The last time I wrote an article here, it was to talk about Afar Region volcanoes, and I promised more to come. This is still a project that I have in mind, but that will have to wait a little longer until I can get an extended period of free time. Today we will go farther away than Afar, to a place whose hellish conditions make the Ethiopian deserts seem like a paradise. I’m here to answer one question: Is Venusian volcanism active, and how and where is this volcanism occurring?
The age and evolution of Venusian volcanism is something that has interested me for quite some time. Understanding extraterrestrial volcanoes might help us understand volcanism as a whole much better. The more I learn about extraterrestrial volcanism, the more I think we are the weird ones. The more I learn, the more I see similarities between Lunar, Martian, and Venusian volcanism, as opposed to Terrestrial volcanic activity, although each rocky body gives volcanoes its personal touch. It might also come as a surprise that I consider Venus to have a more normal volcanism, when our sister planet is full of bizarre volcanic features, from pancakes to spiders, or strange concentric patterns that seem completely alien. But from what I learned about much of the weirdness of Venusian volcanoes often comes from what happens to them after they erupt rather than the volcanism itself, if Earth has erosion, then Venus and it’s highly deformable crust has a lot of ways of fracturing, folding, sinking, or wrinkling volcanoes to change their shape, which we will see more about in a moment. This is added to how Magellan radar images look weird to the untrained observer.
The issue of active volcanoes on Venus has been turning up in Volcanocafé from time to time, usually when new scientific articles come up. One of them is quite relevant to this question, and must be mentioned, this is a 2023 article called “Surface changes observed on a Venusian volcano during the Magellan mission” by Robert R. Herrick and Scott Hensley. This article found changes to a pit crater, in between two images taken during the Magellan Mission that took place 30 years ago. The pit crater seemed to have enlarged and partly filled with lava in between the images. This seems to confirm that some level of activity is ongoing on Maat Mons volcano.
How to reveal Venusian geologic history
The Magellan Spacecraft that orbited Venus between 1990 and 1994 is the best data we have on our sister planet. However, Magellan had overcome the issue of the planet’s opaque atmosphere. Apart from having an atmosphere nearly 100 times heavier than that of Earth, this atmosphere is also constantly covered in clouds of water and sulfuric acid. These clouds help Venus acquire its remarkable brightness in the sky, but at the same time obscure its surface. So to map this surface, the Magellan mission employed radar, which uses microwave radiation that pierces the atmosphere to see surface features. These images are usually viewed in black and white, and they don’t show the real colour of the surface but rather its texture and angle of incidence, among other properties. Other than being able to see obstacles like cliffs or steep hills due to the incidence angle, the texture is one of the more important aspects. The bright areas in Magellan are those with a rough surface texture, for example, young lava flows like those of Maat Mons will have some of the brightest colours because lava has a very irregular surface, something you will know full well if you have ever tried to walk on a’a lava. Faults or cliffs will also show very brightly due to the irregularities of the rock face. Instead, dark areas correspond to those covered in sand or dust, making the surface smooth, while ponded lava lake surfaces can also show as relatively dark areas. There is also low-resolution stereographic topography data of Venus’ surface that I’ll also rely on, revealing the size and locations of mountains and depressions, and helps see how the volcanoes visible on the radar became deformed as time and the planet’s hot plastic crust came into play.
I view the aforementioned data with the Google Venus kmz file for Google Earth that was produced in collaboration between various scientists and Google Earth, and that I will link to at the end of the article.
So we have the data, but now an interpretation is needed. Which principles can be used to establish the age of this alien surface from satellite-based data alone? There are quite a few:
Impact Craters: The approach of using crater density to date the geologic age of the terrain has been used successfully on Mars and the Moon. Incoming meteorites gradually turn the surface of a planet into gruyere cheese, or at least before it gets resurfaced by lava. Venus, however, burns up most meteorites in its thick atmosphere, while only the biggest ones do get through and impact the surface. Craters larger than 35 kilometers follow a similar distribution to craters on other bodies, but the relative frequency of craters under 35 km is smaller than usual since most burn up (or blow up) in the atmosphere. Few craters make crater counting a limited tool that can only be used on very large surfaces, however, it has allowed to establish that the Venusian surface has an average age of about 500±200 million years. This is a lot. On Earth, the surface is constantly changing; one can barely recognize a one-million-year-old scoria cone, but on Venus, we are often looking at volcanoes that are hundreds of millions of years old. Venus is no Io, contrary to what some might expect. Something else about crater distribution in Venus is that it’s relatively homogeneous, which comes to show that most of the surface formed within a short time. Though there is some difference since it has been shown that the young parts of the planet, rifts, coronae, and young volcanoes are about half the age of the rest of the planet (on average). In other planets like Mars, the difference in crater density is much greater, given that the highlands of Mars date to just after the formation of the planet, while much of the Tharsis Rise, in contrast, is floored by lavas that are only about 100 million years old. So the relative homogeneity of Venus’ surface crater density and the very limited spatial resolution of the crater counting due to most incoming impactors burning up has led to a unique interpretation of the planet’s geologic history, that there was possibly one massive resurfacing event or period followed by quiescence. But because the technique can’t apply to small surfaces, there is always the doubt whether small areas of the planet have been resurfaced much later by volcanism, prompting much debate about how dead or active the planet is.
Relatively homogeneous distribution of meteorite craters on Venus surface could suggest a single resurfacing event. But also, because there are only very large craters, it’s hard to tell for small areas. Image from Ghail et al. 2018.
Wrinkles: As the surface ages, it grows wrinkles, and I’m not joking. Most of the planet seems to have contracted over time, probably to balance the areas that are rifting. Wrinkles are born out of the squeeze. They have the structure of folds or thrust faults. I’m unsure whether this process is homogeneous over the surface of the planet, but it won’t be too important for the article anyway, since I’m already selecting through other means volcanoes that are too young to be wrinkled.
Cavell Corona is a wrinkled volcano in one of the somewhat older parts of Venus. Various wrinkle ridges cut the surface in different directions. Most of this area is below the mean elevation of Venus’ surface, and many of the volcanoes have become depressions. The color scale of the radar is changed relative to other images of this post in order to make features sharper.
Fractures: Some fractures on Venus are due to dike intrusions, which show as white filaments in Magellan images, and often can be traced for a thousand kilometers in length. Dikes are not unexpected on an active volcano, but there are other types of fractures that can also be found; some are related to spreading or uplift/subsidence, while others are tension fractures along the crest of folds. Lavas that predate those fractures are cut to pieces, while lava that postdates the fractures will pond inside the topographic pockets created, erasing faults within the areas flooded. Many volcanoes are in major rifts, and we will see some cases of volcanoes that erupt inside the grabens or other volcanoes that are older than the rifting and are cut by it (like Yolkai-Estsan).
Yolkai-Estsan Mons is cut in two by the Ganis Chasma rift valley, which is about 4 km deep and about 100 km wide. Ganis Chasma, together with Devana Chasma, is likely one of the youngest rift valleys on the planet, given that while others are riddled with massive volcanoes, Ganis Chasma only has this volcano and Ozza Mons, and it seems to entirely postdate the main activity of Yolkai-Estsan, despite the volcano having some of the youngest-looking lavas of Venus. The color scale of the radar is changed relative to other images in this post in order to make features sharper.
Deformation: Venusian volcanoes also tend to deform over time, summit areas often develop into a subsidence bowl, where lava flows that formed downslope are left pointing upslope. I think this happens when dense crystals accumulate in the central magma storage, and because these are denser than the basaltic crust, their weight pulls the summit of the volcano downwards into the planet. The counterpart to Venusian magma chambers on Earth are probably the structures known as layered intrusions (named because of the distinctive alternating layers of crystals like olivine, pyroxene, or plagioclase that make them up). On Earth, layered intrusions happen in ocean island volcanoes and in flood basalts; most flood basalts likely hosted gigantic layered intrusions in their center, and a bunch of them are known, although many have likely been obliterated by continental break-up that usually happens after flood basalts. Some layered intrusions can grow gargantuan; for example, the Bushveld layered intrusion in South Africa is thought to have been a magma chamber 400 kilometers wide! On Venus, I believe these same layered intrusions are linked to the structures known as coronae, which sometimes reach hundreds of kilometers across and in one case even 2000 km (Artemis Corona, which is the largest volcano-tectonic structure in the Solar System).
Volcanic edifices also seem to subside as a whole too, due to their weight, so the oldest, most wrinkled, and dust-covered volcanoes have practically zero prominence and are usually below the mean altitude of the planet. Instead, the volcanoes with the youngest dust-free surfaces are usually among the taller ones. So elevation can also inform about the age.
The surface roughness/smoothness: This aspect is the most important to this article. Lavas at elevations lower than 2 km (above the mean planet surface) tend to collect dust, either from the lava itself breaking down or dust carried from elsewhere, which makes them darker in Magellan images. Lavas from above 2 km elevation instead seem to get brighter (coarser surface), probably as weathering and “wind” erosion strip the softer sand and leave behind a field of boulders, which results in many Venusian volcanoes having a bright halo around their peaks in Magellan images, although this could be some change in other properties of the rock too *. This brightening happens much quicker than the darkening at low elevations, and part of Maat Mons’ flank already has a slight brightening visible.
*Edit: Albert pointed out that the radar brightening at higher altitudes is a sort of metallic frost that forms above 4 km elevation in the highlands. It indeed looks as if some of the highlands are covered in “Venus snow” above certain elevations. Some volcanoes must have brought down a remnant of this deposit as they subsided, since it’s present at altitudes of only 2 kilometers in some volcanoes like Sapas or Ozza Mons, likely not as dense as it originally was.
Other events can also redistribute the dust and alter surface brightness in the radar. Landslides leave dark smooth deposits, and some volcanoes can probably smooth the surface with pyroclastic material, which I think happens around the summit of Maat Mons. Meteorite impacts also make some changes; they knock away the surface dust (or fill the ground with rubble) from an area around the crater and drop it into a ring around it, making a brighter circle surrounded by a dark ring or bow-shaped area that is elongated in the direction of the Venusian wind. Even the meteors that burst in the atmosphere can have a similar effect, they create a bright circle where the dust is presumably blown away by the shockwave, but with a darker area just below the airburst, which I picture like the trees standing upright in the center of the Tunguska explosion. In the areas where the dust cover is appropriate to leave airburst deposits, these seem more common than actual craters.
A usual Venusian landscape. On the right, you can see the Toklas crater, formed in an impact that melted the surface of the planet into lava flows. The impact created a lot of dust, which makes a dark area around the crater. On the left instead there’s an airburst deposit, where a meteorite exploded above Venus surface, a smaller dark circle several kms across must be right below the explosion, where dust held to the ground, a much bigger area 150 km across is probably where dust was swept away by the shockwave, or so I reason. These craters overlie an ancient volcanic terrain. Near the center of the image, there appears to have been a volcanic center. There is a pancake visible (strange volcanic structures that I think lie in various spots along a spectrum between cryptodomes and giant perched lava lakes) and a hint of a corona volcano just below as a concentric pattern. Giant dikes radiate as white lines, and, on the left of the image, there are also low shield volcanoes dotting the ground. The lava flows are smoothed by dust and weathering to the point that they can’t even be distinguished. The color scale of the radar is changed relative to other images of this post in order to make features sharper.
Two volcanoes of different ages. Ledoux Patera is on the right side, with its black “eye” which is a ponded lava lake. Ledoux is younger (“Ozza-aged”); its lavas are bright on the radar. Instead, Maram Corona is older, on the upper left side, with older lavas covered in thick dust or weathered, which makes them dark to the radar, though it’s still likely on the younger side of Venusian volcanoes. Numerous cracks run through both volcanoes, some are dikes of Ledoux Patera that cut through Maram, others are fractures related to folding, rifting, subsidence, and similar. The color scale of the radar is changed relative to other images of this post in order to make features sharper.
The Ozza-age volcanoes
The surface roughness/smoothness is the main criterion that can be used to find young lava flows, since it’s the most direct way of finding the age of the lava. I called the volcanoes with the youngest looking lavas (those that don’t seem, or mostly don’t seem to be smoothed by dust/weathering) Ozza age volcanoes, given that Ozza Mons is by far the biggest system among them. I reason that the active volcanoes must be among them, assuming a similar rate of weathering across the planet.
A total of 16 volcanoes could be classified as Ozza age, give or take a few, since the distinction was not always fully clear. Do consider that Venusian volcanoes are gigantic, often far superior in size to terrestrial stratovolcanoes or shield volcanoes. All of these youngest systems turned up in the same part of the planet, being found between 180 and 300 degrees longitude and in tropical regions, below 25 degrees latitude. The area is not too surprising since the main rift systems of Venus run around most of the planet within the tropics, and also because the volcanoes are clustered around three topographic swells called Atla Regio, Beta Regio, and Phoebe Regio. Though I’m surprised the area around Artemis Corona, which hosts very important rifts and many of the largest Coronae in Venus, did not show to have any particularly young volcanism. The map below shows the location and name of these volcanoes, though not all have been named.
Colours show elevation (red=high areas, blue=low areas), and brightness shows the radar data (white is rough terrain, dark is smooth, black patches are around young impact craters). The volcanoes indicated with red circles are the ones that have Ozza-aged lavas, unweathered. M. stands for Mons, and P. for Patera. The basemap is from the USGS Astrogeology Science Center.
However, most of these volcanoes do not seem to be active, to the point that I think the list can be narrowed to only four potentially active volcanoes. How is this? Well, the lava flow roughness is not the only principle that can be used to determine the age of the volcanoes. Many of these are deformed or faulted, which shows they haven’t erupted in a long enough interval, which makes me think they shouldn’t be considered active, at least not by Earth standards. Most of the volcanoes are located along the tropical rifts of Venus which can be used as an age constraint, given that the majority of them, for example Yolkai-Estsan Mons, or two of the Devana Chasma volcanoes have massive fault scarps cutting through their edifices and summits, which are the result of rifting, but there are no lavas that seem to overlie or pond in these fault scarps, so there must have been a long interval volcanic inactivity and tectonism acting on their volcanic edifices.
Another example of a volcano that no longer seems to be active despite having some of the youngest lavas of Venus is Sapas Mons, which is the only one of the Ozza-age volcanoes that is not on top of a rift, located on the flank of the hyperactive Atla Regio. Sapas, like most Venusian volcanoes, is gigantic. Its lavas cover an area of almost 170,000 km2, which is nearly twice the size of Iceland! This is also just a bit less than its younger neighbour Maat Mons. At present Sapas is a very low volcano that rises barely 2 kilometers above the average height of its surroundings, but I think this could be an effect of subsidence that has elapsed since its construction, originally I think Sapas it may have been more like the actively growing Maat Mons volcano that presently towers nearly 7 kilometers above the average height of its surroundings, and 8 kilometers above its lowest elevation lavas. But the most clear sign that Sapas is long inactive is the shape of the summit area.
Sapas’ summit area used to possess two lofty peaks that are now depressed into the volcano due to subsidence. I think the volcano is also likely to have been taller and steeper originally, later affected by subsidence, more akin to Maat, and this subsidence continues to affect the shields until they end up with the flat or reverse topography of the volcanoes in some of the older parts of the planet.
Originally, the shield volcano had two peaks, each hosting a steeply perched lava lake or piston uplift structure over 10 kilometers wide. The steep flanks of the two peaks gave way to landslides that ran downslope, similar to many lava flows that extended radially from the twin summits, following the downslope direction. However, the volcano has deformed in such a way that these lava flows and landslides now point upslope; as indicated in Magellan topography data the entire summit area has subsided into a double bowl 100 kilometers long and 3 kilometers deep, as deep as the tip of the lowest elevation lava flow of Sapas, likely due to the weight of its dense central intrusive core/ layered intrusion. If Sapas Mons was still active, it would have erupted inside the subsidence bowl, making a ponded lava plain, which is not the case, which precludes the volcano from having erupted in a really long time.
The southern summit of Sapas is shown to have originally been a steep mountain, not a depression like it currently is.
There are additional signs of Sapas’ long dormancy. First, the ridge around the subsidence bowl is fractured in places, likely due to tension along the crest of the fold, and the fractures cut through the lavas. Second, is that a bright halo of erosion/weathering encircles the volcano above 2 km above the mean Venus elevation. And lastly, although the lavas are generally of similar brightness to those of Maat, beyond the bright halo, Sapas lacks lavas as bright as the brightest/roughest low-altitude flows of volcanoes such as Maat, Ozza, or even Theia.
Another volcano that looks very young is the impressive Theia Mons volcano, a junction between three major rift valleys and two minor ones that forms the roof of Beta Regio. The volcano covers over 300,000 km2 in young Ozza-age lava, and probably has older lavas over a larger area. Its young edifice postdates the bulk of rifting of Devana Chasma (but not all), the rift being much deeper in adjacent areas than on the edifice of Theia. However, the summit of the volcano has experienced massive subsidence and forms a vast 70 km wide depression that is 4 km deep, making even the largest terrestrial calderas look small. Though this may not be a caldera collapse, but the subsidence of its central intrusive complex. Since the central depression reaches as deep as the lowest elevation lavas of the shield, then if the volcano was active, eruptions should be ponding inside of it, but the Magellan radar shows a dust-covered summit depression cut by fault scarps and no sign of recent lava filling it. This volcano is another example of why almost all Venusian volcanoes can be ruled out as being active, for one reason or another, or usually several.
Topography of Theia volcano. Three major rift valleys converge on the mountain. Zverine Chasma on the west, and the two branches of Devana Chasma running north and south of the volcano. The edifice postdates the bulk of this rifting, although it’s slightly collapsed by the final rifting. A major depression is located at the summit. Contours are 1 km increments in elevation.
The central subsidence of Theia is 4 km deep over the summit of one of Venus’ youngest volcanoes and triple junction. The bottom is covered in dust and fractures, however, with no sign of a lava fill.
Something else I’ve done is to try and estimate the age of the tropical rift systems with crater counting. Ozza-age lavas cover a very small area of the planet, making it impossible to use crater counting, but the rifts are more widespread and they are linked to the youngest Venusian volcanoes. These rifts often seem to entirely postdate the many volcanoes that cover all of Venus’ surface, showing that at some point there may have been a transition from a very volcanically active stage to a stage of weak volcanic activity, where tectonic processes instead dominated. However, some volcanoes have grown after the bulk of activity of the major rift systems, like Theia or Ozza Mons, that occupy the two largest rift junctions of the planet. And four, as we will see later, have lavas that postdate even the youngest rifting. So, having an idea of the absolute (average) age of the last rifting across the tropical rift systems was important to judge whether the planet is geologically active or not, and no doubt this has been done already, but I wanted to do it myself. I can only do so with craters of over 30 kilometers since the smaller ones don’t have the typical size distribution and do not always make it possible to see if the floor is faulted.
The result is that in an area of 12 million square kilometers that is affected by rifting there are 12 meteorite craters that predate the rifting, 2 additional craters that may postdate rifting but were too small to tell for sure but anyways also too small to be included in the counting, and two >30 km craters that respectively postdate the rifting and Ozza-age lavas inside Dali Chasma. One of these two last craters has 34 km diameter and is located north of Yolkai-Estsan Mons, it postdates fault systems belonging to Ganis Chasma that in turn cut and thus postdate Yolkai-Estsan Ozza-age lavas. The other crater is a 40 km diameter impact on Ozza Mons (Uvaysi crater) in the center of Dali Chasma rift system, the impact showered the whole SW sector of Ozza, including some of the best preserved lavas of the planet in smooth dust deposits. The bottom of the crater doesn’t seem cut by Dali Chasma faults, but the rim does have some faults that likely postdate the crater. I think a fissure of Maat Mons likely erupted inside Uvaysi and resurfaced the floor, but the crater itself, while postdating the main shield-building episode of Ozza, predates some of the last rifting of Dali Chasma that cuts through all but the last Ozza lavas.
Venus has 189 catalogued craters of over 30 km in diameter and an estimated mean age of 500 Ma, so taking into account the area of the planet, it is possible to compare the mean crater density of the planet with that of the rifting area, and the density should be proportional to the age. Considering the one crater, this gives a mean age of 100 million years for the rifting areas, which is a lot more than I was expecting to be honest, but at the same time shows the rifts are much younger than the rest of the planet, so there is clearly a protracted history of volcano-tectonic activity here. This orientative age doesn’t imply there’s no active rifting on Venus, given the crater that does postdate all rifting is away from the central axis of the rift, an area that may have been abandoned in favor of more focused activity. But combined with the crater on Ozza’s flank, it does seem to point at Venusian volcanism being very old, and it also points to rifting being far slower than on Earth’s continental rifts, if active at all. While there is a lot of uncertainty, even the 16 Venusian volcanoes of youngest appearance are likely to have had most of their activity before 100 million years ago. This volcanic slumber gets so bad that I’m not sure which planet has erupted more lava in the last 200 million years, Mars or Venus.
The potentially active Venusian volcanoes
So, which are the volcanoes that could be presently active? The first is an area of 3,300 km2 of lava, very bright in the radar, that is ponded inside Devana Chasma in Phoebe Regio. The volcano has no name, and I simply call it the South Devana Chasma volcano. Since the topography is complicated and the lavas appear to mantle it, then perhaps the lava is hundreds of meters thick, probably over 1,000 km3 in volume, which is not much. There is also an older apron of Ozza-age lava covering 30,000 km2 that was erupted before Devana Chasma started to open; additional episodes must have followed inside the rift, associated with continuing faulting, until the final episode that entirely or almost entirely postdates rifting. If the rift valley is still active, then this unnamed volcano must be active too.
Lava field inside the southern part of Devana Chasma, which is unaffected or almost unaffected by the rifting.
Another potentially active volcano is Kono Mons, which is located in another major rift system of Venus, known as Zverine Chasma. The volcano grew as a shield that covered an area of 70,000 km2, though only a few of these lavas can be considered Ozza-aged I think, the rest are older, then the rift valley opened and split the volcano in two. More lava was erupted inside Zverine Chasma, maybe 1 km thick and covering 6000 km2, so 6000 km3 in volume. The surface of these lavas does not have any rift-related faults on them, so they must postdate all rifting, but there are small fractures and deformation that seem associated to subsidence or uplift of the volcano’s center. If the rift system is still active, then Kono Mons must be actively erupting too, given the lack of rift fractures on the lava, making Kono a potentially active volcano and among the few youngest eruptors in Venus.
Lava flooring the summit of Kono Mons is not affected by the rifting of Zverine Chasma that cuts through Theia Mons lavas. The few fractures seem related to uplift of the floor.
The last two potentially active volcanoes, which also have the best chances of being active, and likely contain the vast majority of lava erupted in Venus during “Ozza times”. They are the two goddesses of Atla Regio, Maat and Ozza Mons. Because I think these volcanoes deserve their own article, I will publish a second part looking into the construction of the volcanoes, the way they erupt, and how various features like coronae, giant dikes, and lava flows may be related.
Conclusion
Since I’ve learned of Venusian volcanism, I’ve been swinging between two ideas of Venus: that of a dead planet that was resurfaced during an apocalyptic, very old volcanic episode, and that of a live planet that still has several volcanoes going off at any given time. It turns out that it is not exactly any of the two. The volcano-tectonic activity that we see on the planet seems to have spanned hundreds of millions of years, but it can’t be considered to reach a level of volcanic activity anywhere near what it once was. I thought some volcanoes, like Theia Mons or Tepev Mons, that are relatively tall, would turn out to be active, but closer inspection shows them to be long dead. As far as I can see only 4 volcanoes may still be actively erupting, and only one of them vigorously, Maat Mons, the others seem to be but a shadow of what ancient Venusian volcanoes were hundreds of millions of years ago, when in a relatively short span pf the planets history they covered all the surface of the planet in lava and cut by countless giant dikes, likely feeding layered intrusions that were hundreds of kilometers across and more, and channels of lava that run for several thousands of kilometers in lenght. It’s unclear if this has been a continuous fading trend of the planet’s volcanic activity towards oblivion, or if volcanism is something cyclic or episodic that at present is going through a low phase, but it’s clear that the Earth is a far more consistently geologically active planet than its siblings.
References
Richard C. Ghail, David Hall, Philippa J. Mason, Robert R. Herrick, Lynn M. Carter, Ed Williams. VenSAR on EnVision: Taking earth observation radar to Venus, International Journal of Applied Earth Observation and Geoinformation, Volume 64, 2018, Pages 365-376, ISSN 1569-8432, https://doi.org/10.1016/j.jag.2017.02.008.
(https://www.sciencedirect.com/science/article/pii/S030324341730034X)
David Sandwell, Ross Beyer, Ekaterina Tymofyeyeva, Catherine Johnson, Stafford Marquardt, Jenifer Austin, Kurt Schwehr. Google Venus: https://topex.ucsd.edu/venus/index.html
Robert R. Herrick, Virgil L. Sharpton, Michael C. Malin, Suzanne N. Lyons, and Kimberly Feely. (Venus Crater Database) “Morphology and Morphometry of Impact Craters”, (1997, U. of Arizona Press, eds. S. W. Bougher, D. M. Hunten, and R. J. Phillips, pp. 1015-1046). https://www.lpi.usra.edu/resources/vc/vchome.html
Robert R. Herrick, Scott Hensley ,Surface changes observed on a Venusian volcano during the Magellan mission.Science379,1205-1208(2023).DOI:10.1126/science.abm7735. https://www.science.org/doi/10.1126/science.abm7735
Very good article indeed! you are indeed highly intelligent ( which Im really not ). Since Venus and Earth are the solar systems largest rocky planets and therefore they haves the slowest cooling rates and they carry the most internal radioactive internal heating. Size and heat maybe thats one reason why Venus and Earth haves mobile and deformable crusts unlike the smaller cooler Mars thats more of a really thick litosphere lid. Venus should have a plentiful geothermal budget due to its size and more than enough internal heat to drive frequent small scale volcanism. I guess as you conclude in the article the small scale eruptions are perhaps rather common in the younger volcanic centers while Venus is not in the mood of full LIP scale resurfacing today. The mass of Venus and its internal heat budget makes it likey for small scale activity to be a frequent thing. We needs more radar mapping orbiting spaceprobes to rescan the volcanic centers to check for crater changes and new lava flows over the last thirty years thats spanned from Magellans mission, that is the best way to evalute rates of frequent small scale volcanic activity on Venus. ”Volcanic Dusk” in terms of avarge activity maybe much more analougus to apply on the smaller Mars that seems to be in its sunset days on volcanism frequency but even Mars is not completey dead yet
Venus is a real all consuming hellworld due to the geological- climate sillica – weathering CO2 cycle have broken down completely on Venus. This cycle is self – regulating on a planet thats large enough to be geologicaly active and cool enough to have oceans and rainfall if it haves a good atmosphere. Its very eerie since its well known due to atmospheric studies in the past Venus was a cool watery world not unlike the early Earth ( but a bit warmer ) since closer to the sun with frequent volcanism and oceans of seawater with a fairly dense nitrogen atmosphere like Earth, there may have been large Venusian oceans and large hotspot volcanoes perhaps even some kind of form of plate tectonics billions of years ago when the sun was smaller and cooler back then Venus had likey a fully working carbon – sillicate water cycle thats pretty much self regulating as long as the planet is geologicaly active and cool enough for rain and sedimentation so CO2 constantly circulates between mantle eruption outgassing and ground burial as carbonates.. like it does on Earth but on Earth this important cycle have broken down.. the CO2 scubbers ( water) on Venus are gone.
Breaking of this important cycle on Venus likey is due to the Sun was getting brigther and brigther. Venus water ( a strong greenhouse gas ) likey became its own downfall towards the absolute hell that it is today. When the sun got brigther Venus atmosphere could hold more and more seawater vapour due to increasing evaporation and it simply got hotter and hotter and hotter until the oceans boiled away all the water vapour , thats a strong greenhouse gas so temperatures skyrocketed and sillica – weathering CO2 cycle broke down. Without water and rainfall ( being too hot ) the scrubbers of volcanic CO2 vanished forever. Active volcanoes coud then fill the atmosphere with as much CO2 as they wanted without that gas being ”rained out” as carbonates. That is when you got hell started .. billions of years of eruptions and volcanic outgassing have now resulted in a 100 bar pure CO2 atmosphere who Venus thats now too hot for a water cycle and too dry for tectonics cannot remove this atmosphere. And its only going to get worse the brigther and larger then sun becomes maybe the whole planet may melt completely in a few 100 of millions of years in the future under a brigther sun with the same nightmare atmosphere
This fate also awaits our planet Earth when the sun gets brigther and larger in perhaps a billion years or so If Earths oceans evaporate very quicky in the far future the water vapour coud send global temperatures 1500 c ! melting the entire planets crust under 100 s of bars of pure water vapour specialy so if the magnetosphere is there and prevents the water from being stripped away. If Earth looses its water more slowly then temperatures will soar up slower but the far future is grim indeed
Thanks Jesper. Well, I’m good with basic geologic principles and have excellent spatial vision, but I struggle a lot with other mental skills, so it depends a lot on how intelligence is defined…
“The mass of Venus and its internal heat budget makes it likey for small scale activity to be a frequent thing.”
It would be visible in Magellan images if there were such a thing. A volcanic field inside a crater or one of the major rifts, or covering the ejecta of a recent meteor impact (those that have very distinct bright and dark radial stripes and halos) or flows with very bright colours in the radar. But the only good candidates for such recent activity are the ones I’m presenting here. I will keep searching, and if something new pops up I will be sure to mention it in the next part, but it’s not looking that way.
A new magellan woud be very useful to track surface changes its been more than 30 years now
You are excellent at processing information into data and producing a sicentific result so likey a very high IQ you are well suited for being a researcher perhaps better that you university in Scandinavia rather than in Spain. Not certain but I guess you likey does not need to pay here but Im not soure but for a born citizen here its cost free. But the terrible weather maybe making that impossible I myself can barely function in this weather
Im myself is so busy with various projects and other stuff that I may not have much time for VC for a very long time but its good that there are writers like you and we really needs even more writers for VC !
Venus is certainly in a low intensity era of volcanic activity compared to before but due to the planets near Earth size I guess there is plenty of internal fuel left for future episodes of major volcanism. 🙂 with an ever heavier CO2 atmosphere and a sun thats only getting hotter it will make the greenhouse effect even worse the whole planet maybe the first one to melt completey under its heavy atmosphere even way before the sun becomes a Red Giant
Woud Venus surface even be visible even without the sulfur clouds in the upper atmosphere? its known that all clear gases scatters light and things fades in the distance like it does on Earth. The denser an atmosphere is the more light is scattered at Venus its nearly 100 atmospheres of pure CO2 pressure, nearly all the carbonate mantle materials in the atmosphere due to the carbon – sillicate cycle being broken down. An atmosphere as dense as this will have some very strong light scattering indeed. I read that visibility in clear venusian air at the surface is only three kilometers before light scattering makes the horizon or surface features fade away in the distance. Maybe its possible even without the clouds that Venus woud just be a pale blue orb from orbit with no surface detail at all because its incredible strong reyleigh scattering. Its likey that the sky color from the ground even without clouds maybe white too simply because scattering is so strong. The sun seen from the ground at a cloudless Venus maybe a dark red orb in a white sky due to the strong scattering…
Mars is the reverse stuff an atmosphere so thin that its equal to almost 40 kilometers above Earths surface, the reason Mars have a sky color is the fine dust, clear CO2 at souch very low pressures have a very weak scattering effect. At noon with least scattering I guess that without any dust, Mars maybe woud have a space black sky only being somewhat blue at evening.. .
Thanks Hector! I always enjoy going off-planet
Thanks Albert. Sometimes one gets tired of seeing just one planet all the time.
I am content with this planet, however I think the piece is excellent. It must have been a bit of work.
When I see those wrinkles I wonder whether Venus shrinks. Could that be?
Or could it be the pressure?
(When in Pathology you take out the bowels that are folded and “wrinkled” you have to place them on the floor as they spread and then, instead of being “wrinkled” they are smooth with the room they have.)
The biggest miracle is that resurfacing event and why it happened. Collision with another fate that lucky Earth had?
Venus does not have any subduction zones or oceanic ridges where energy can
bubble out slowly. Venus during catastrophic resurfacing haves maybe an upper mantle thats acting as a single global mantle plume during souch times
Thanks Denaliwatch. Venus could definitely have “shrunk” (while growing outside), the planetary resurfacing event must have taken up quite a lot of magma from inside the planet after all.
“It must have been a bit of work.”
It has. I tend to get carried away with articles, originally, in my head, the article was going to be much simpler.
The bright radar halo around high peaks is a common feature on Venus. This is attributed to a metal-containing deposit, above around 4 km altitude and disappearing at 9 km. (The heights vary across Venus.) It is commonly attributed to a deposit from the atmosphere, a kind of snow.
Yes, I noticed one scientific article hinting at some atmospheric process (it’s why I mentioned the “other properties” thing), but I didn’t have time to look it up, I may have provided an alternative explanation in the process though.
The youngest lavas of Maat and Ozza don’t have the bright halo. It’s quite striking to see the volcanic field in the NW part of Ozza’s summit that is distinctively darker than the super-bright older lavas around and overlie the rifting and fractures that cut the edifice, but still has an overall high brightness like that found on Maat Mons lavas
I just noticed that the Maxwell Montes are “white” above 4 km, pretty much all the ground and all of a sudden, must be this metal-bearing snow. Tepev Mons and some Coronae and other highlands also have it at over 4 km.
But the only way it works with the volcanoes is if it’s mostly a really old deposit that endures and builds up over a long time, that in flat places has been covered in dust and in Maat and Ozza volcanoes by lava. For example the dust apron of Uvaysi meteor crater is at over 4 km and doesn’t have the white deposit, the impact may be too young (though I’m not sure if it drops on dusty surfaces). And also some volcanoes must have brought down the deposit from higher altitudes as they subsided, cause in Sapas volcano the bright halo clearly starts at 2 km and only 1.5 km on one side, while Ozza Mons also has the bright deposits at barely above 2 km in much of the shield, and Maat and Theia Mons have their bright halos start at 3 km. Although Maat’s is very subtle and only on one side of the mountain, it may be thin. That said this would explain why the brightness starts at different altitudes in various volcanoes which was driving me crazy.
It coud be a kind of pyrite sulfide metal snow it should vaporize at lower altitudes and higher temperatures in some areas. Im not soure how the snow behaves in the Magellan radar as its a soft and likley powdery substance or perhaps even like a consensed out frost without falling from a cloud it maybe is just condensing and freezing out as frost from vapor rich carbon air at higher altitudes but crystals falling from the lower cloud layers maybe a possibility too.
Articles mention that the radar reflectivity comes from the electric properties of the metals. But maybe some sort of spiky crystalline deposit would be worth considering too. As for the exact substance it falls outside my field of knowledge.
Not all high reflection areas may have the same cause. And on Maxwell Montes, different sides have reported different altitudes for the onset of the snow. That is not fully clear: I expect that the radar altitude measurements on steep slopes can be quite far off, because of the limited spatial resolution. Wind direction may also be important.
When overlaying the topography and radar in Google Earth, the bright deposits seem to start slightly at about 4 km on the Maxwell Montes, and then around 5 km they get really white.
In Ozza Mons, the brightness at about 3 km is in places very strong and seems to obscure the flows underneath, which could indeed fit some sort of precipitate that mantles the lavas. I had noticed it was really hard to tell apart flow boundaries on Ozza’s high flanks, but didn’t give it much thought, but it could be explained with this is precipitate if it survives the subsidence into lower elevations.
Wondering – as Venus is supposed to have had oceans – if salt is a possibility at all.
Great Salt Lake, Utah by NASA:
https://modis.gsfc.nasa.gov/gallery/individual.php?db_date=2024-04-25
Whether Venus ever had an ocean is under discussion. Climate models show that if an ocean was present, it could have survived for a while. On the other had, atmosphere models show that volcanic degassing contain little water, indicating that the interior is dry. That would imply Venus lost its water very early on, before the planet had solidified, in which case it has always been like it is now. Pick your choice.
https://www.nature.com/articles/s41550-024-02414-5
Thank you. No choice really. They say at the end:
“These results indicate that Venus probably never experienced conditions conducive to ocean condensation. This result is in agreement with recent modelling work indicating that a Venus born with a hot steam atmosphere would never have received a low enough insolation to condense its water reservoir.”
It would be different if the Grand Tack Hypothesis were right and Venus had been closer to Earth and further from the Sun and Jupiter had pulled it in, also if the theory of Theia were right and the collision with Earth had had effects on neighbouring planets.
We see a lot, and yet we know so little as we cannot step on hot planets like Venus and Merkur or planets made of gas.Probes get lost by the heat. But there will be some progress.
Good article to be studied by me again during the week to come.
But even if Venus had been closer to Earth with a proper tilt and rotation plus water complex life would not have developed in the short time. Maybe simple life.
Do remember that science is a perpetual discussion. Their conclusion is based on a solid piece of modelling, but there are assumptions in there. Outgassing may be different. Water may have arrived later then they thin k. Oceans may not have affected the mantle, in the absence of an asthenosphere and subduction, in which a dry mantle does not prove an absence of oceans. These assumptions will be tested by them and by others in the future. In the end, all the gaps will have been filled and a conclusion reached. They have a strong case but perhaps not unassailable.
David Grinspoon who is referred to under the paper just loves Venus. He learnt that in early days from Carl Sagan who he heard as a boy his father being in the same Uni as Sagan (Harvard) and being friends.
In case Venus has been displaced by Jupiter it is a planet to have pity with.
Bravo !!!
Here, we sorta-regard water-lubricated ‘Ring of Fire’ subduction related volcanism as the norm, finessed by secondary effects from long-subducted, intact or split slabs . Like the ‘weirdness’ recently discovered under US Mid-West ??
( So, will that area ‘delaminate’, rise as fast as Tibetan Plateau did ?? Where will the Mississippi / Missouri and Great Lakes etc go ?? Heh, heh, heh… )
But, Venus seems to be near-pure ‘intra-plate’ tectonics…
Thanks Hector for a fascinating and detailed article! Especially as I’ve not really looked at Venusian geology much at all, and not since the Magellan mission.
I’d go with a qualified “live planet”. This is only inference, but there is no reason why Venus cannot have mantle plumes. The size of Venus is nearly identical to Earth and the internal heating will be just about identical too, from radioactive decay. That heat is going to cause magma to rise. Perhaps not as enthusiastically as on Earth since there’s subducted water lubricating the circulation through the mantle here.
On what you said in your intro, I would agree that Venusian volcanism is probably the standard model. Mars and Io being similar.
Earth of course has water to make everything go. And the other one I would be really interested in is Europa.
What you can see in the picture is the white ice with large amounts of red coloration. Almost certainly that red pigment is iron (III) oxides. Which means the ocean underneath is like the preoxygenation terrestrial ocean: full of iron chloride. (Although there’s no oxygen on the surface of Europa any ferrous chloride reaching the surface will be rapidly oxidized to ferric oxides by radiation.)
The thing of course is where did that iron in the ocean come from? And the likely answer is submarine volcanoes interacting with the acidic ocean water.
And apology Héctor for calling you Albert. My mind was so full of Monses I was negligent.
Fixed in the comment..
Thanks. Much appreciated!
Thanks Bruce. I could definitely see Europa as a very volcanically active moon below the hydrosphere.
Submarine volcanoes coud be the furnaces of life… giving of heat energy, nutrients there thats required to cook up alien life itself there coud be deep sea Europa fishes there or most likey alien deep sea microbes eating volcanic fluids…
There is probably a lot of H2O2 ice in the Europa crust too, being so irradiated. I have seen somewhere that this might actually make the upper levels of the ocean oxygenated enough to support fish although its not a settled matter. But basically it might actually be possible to support more advanced life, and although certainly very different to our own life it is likely to have convergent evolution to a degree.
I guess, basically, theres a non zero chance the first contact with the ocean is met by some curious ‘fish’ 🙂
Maybe the most exiting option is if biology there, or on Mars, does exist but actually DOES turn out to be related to us. It doesnt at all imply a single genesis, despite expectations. Because obviously all 3 are not and never were connected, it implies a common ancestor ehich was capable of getting to all 3. So either panspermia is real, or maybe more likely we are a seeded world by something else. We are so close to answering our oldest question, are we alone…
Mega-impact ejecta could transfer bacteria from around the LUCA era…
Thats the thing, it cant really, they dont survive the impact… the only thing surviving a impact is the dissociated free carbon atoms, impacts are so energetic they equate to nuclear explosions in power level for even couple meter scale rocks, I cant think of a possible way to survivd re entry without an artificial and engineered craft. We have technically done this ourselves already on the Moon, there actually probably are living bacteria on the moon at least on our spacecraft.
If it turns out the U in LUCA is common to other planets too then I actually lean more to the idea it encountered spacefaring aliens that moved it instead of it somehow surviving an impact and in the case of a trip to Jupiter many years in space, possibly millions of years.
A small meteor ( less than 1 meters wide ) can easly carry hibernating alien bacteria sheltering inside towards a new world and surivive entry like the marsian meteors does, if its small enough the forces on reentry and impact are much less of course it gets slowed by the atmosphere, the outside melts but the inside remains cool..
https://m.youtube.com/watch?v=uCYyog_CD_c&pp=ygUSdmVudXMgY2xvdWQgY2l0aWVz
It woud be the ideal place to live in for me: IF I was born in the future massive floating cloud city societies on Venus having an lofty apartment in the sunny clouds just like at Bespin in Star Wars. At Venus atmosphere the pressure level at 56 km gives a very earthlike outside temperature with only that you needs an oxygen mask when you are going outside the floating city habitat. Above the upper clouds I guess the skies will be blue due to the clear upper atmosphere should scatter blue light
Its not a good place at all while being drunk and risk stumbling and falling off an outside platform and down into the terrible inferno below..still I wants an air lock and an outside balcony where I can walk around in just an oxygen mask 1 bar of CO2 or 0,7 bar pressure of CO2 will likey feel pretty warm due to its greenhouse nature
Thank-you for the mission to Venus, Hector! Why does volcanism occur on Venus without plumes and plate tectonics?
The rifts look a bit like the failed rift systems of earth that pull for a while, but are too weak for the formation of a divergent plate boundary. The Jordan rift valley or the Rhine rift valley (Upper + Lower Rhine) are examples for volcanism on rift zones without the formation of plate boundaries.
Maybe there are mantle plumes that drives the venusian rifts and uplifted litosphere domes and their resulting bilisters and coronae?
Thanks Volcanophil. While Venus doesn’t have plate tectonics, it does have some sort of rifting and also has some convergence areas (the tesserae regions, which seem to be folded and have a thick crust). A lot of the larger volcanoes align with the major rifts, and the last major volcanism (Theia and Ozza) seems to have been over the major junctions, so there is some relation there.
There must also be some connection with the odd distribution of volcanic activity over time. One possibility may be that melt accumulated in a growing Venusian asthenosphere at some point, eventually reaching a very unstable state that gave way, and then the whole planet was engulfed in a planetary volcanic flood, which also generated a form of tectonics and maybe also convection in the mantle. And that volcanism has been gradually dwindling since then, retreating to the rifts, then finally to the junctions. But there may be other explanations.
As you are available here, Hector, I have to ask you a few things about Hawaii. I get such beautiful pictures by Bing i.e. for Hawaiian volcanoes with lava erupting in a rugged mountain terrain, then flowing downhill, then creating a few lava lakes, and also lava running down rocks into the ocean, and I do not know where this would be. I would really like to have a more precise history of Hawaiian volcanism with good pictures.
I am incredibly bored by discussions about vent 1/ vent 2, that is really only interesting for some Kilauea Nerds.
Jespers pieces were very interesting though, I loved them and would study them again if I ever get to Big Island.
But the vent discussion is not for a majority of people – I guess – interested in the Hawaiian-Emperor Chain, too detailed. At least for me.
“I would really like to have a more precise history of Hawaiian volcanism with good pictures.”
I could (eventually) do a good overview of both the pre-1800 and post-1800 AD history of Hawaiian volcanoes. Doing a pre-1800 history would be more valuable since none exist to my knowledge. I also have material for a paused article where I was going to talk about Maui Nui and the construction of the Big Island.
I do really like to get into as much detail as possible about stuff, though, and particularly if it comes to lava flows, while probably most people are interested in a lighter read or following developing situations in volcanoes, particularly those that may explode violently.
Yes, that would be nice.You could do two parts or a trilogy if necessary like Albert did with Wrangellia or Jesper with Nyaragongo.
https://www.spacevoyaging.com/wp-content/uploads/2023/05/main-qimg-29717386cdbb07b1631a9bd0d510160f.webp
Mars surface seen by the russian venera landers, its impressive stuff and completely unexpected during the cold war that USSR where doing souch technological feats like this around 40 and 50 years ago. I think this is a ( disturbing ) image thats whats it looks like for your eyes if you where on Venus surface, its a sickly and twisted world
Venus surface seen by the russian venera landers, its impressive stuff and completely unexpected during the cold war that USSR where doing souch technological feats like this around 40 and 50 years ago. I think this is a ( disturbing ) image thats whats it looks like for your eyes if you where on Venus surface, its a sickly and twisted world
“On the possibility of convection in the Venusian crust”; Physics of the Earth and Planetary Interiors
Volume 361, April 2025, Viatcheslav S. Solomatov, Chhavi Jain, doi.org/10.1016/j.pepi.2025.107332
Using new fluid dynamic modeling, researchers show that Venus’ crust could support convection. This, in turn, could help explain how heat from Venus’ interior could be transferred to the surface, where temperatures reach 870 degrees Fahrenheit (466 degrees Celsius) and volcanoes and other geological features show clear signs of melting, according to a statement from Washington University in St. Louis.
The accompanying statement (presumably from their press office) is a bit strange. It is factually correct but Venus’ surface temperature is not caused by volcanism and ‘volcanoes showing signs of melting’ shouldn’t need saying. The paper itself only states that under some conditions (small grain size, mainly) convection in the solid crust could occur. Otherwise you’d need some melt in the crust to get it. A partially molten crust is probably excluded for the same reason that we know there is no asthenosphere: it would cause the mountain regions to sink down too fast.
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTIgodqsRggaeGsVQPX28r5f9xwIw6OYBmlkA&s
Venus compared to Mars its important to understand despite the size differences their geological surfaces are quite similar in some ways with both planets lacking true plate tectonics and are full of massive intra plate volcanoes, massive lava plains and failed continental rifts the venusian casmas maybe sucessful if they are still spreading. Venus is nearly 8 Mars masses so it likey generates 4 to 5 times more radiogenic internal heat than Mars does that will lessen the thickness of Venus litosphere compared to the thicker crusted smaller Mars.
Venus haves no really Earthlike tectonics in terms of oceanic spreading ridges and subduction zones it does not have that. But it does haves its own style of tectonics like compression belts and crustal spreading rifts. The large volcanoes on Venus are feed by mantle plumes these are tought to be responsible for the venusian spreading rifts. Venus haves a larger and hottest interior than Mars so its crust like Earth is more plastic and movable than smaller Mars. Its still unknown if Venus haves grantic continental crust or if it ever had true plate tectonics. Most of Venusian crust is likey primitive and basaltic gabbro like Mars. The Venusian highlands are intresting like Isthar they sits much higher than the basaltic lowlands perhaps suggestive of likey a lower density perhaps an indication of the rock materials being granitic in composition. The highlands on Venus may also just be mafic gabbro plutonic materials thats been compressed into highlands pushed by the rifts rather than being ancient continents thats frozen in place.
They are still quite similar just that Venus is hotter and thinner skinned than Mars is..
The atmosphere of Venus hot enough to melt Pb (Plumbum, Lead). Melting point of Lead is 327°C. Venus has an average “air” temperature of 464°C. The atmosphere has strong convection (Hadley cells), but without the water dynamics that we know on earth.
Its hot enough for the ground to glow very dull dark red at night
But hot enough for metals to melt, and on other places cold enough to solidify the same metal. Earth’s volcanoes do the same occasionally with sulfur that can build solid deposits which melt if geothermal heat enters in it. Mauna Loa has a Sulfur Cone that did sulfur flows during SWRZ eruption 1950, when geothermal heat entered the sulfur sediments.
https://www.usgs.gov/observatories/hvo/news/volcano-watch-a-peculiar-flow-sulphur-cone-along-mauna-loa
I’d imagine that something like this is possible for metal deposits on Venus.
I dont think there are any metals with a transition point that fits with Venus average temperature and can occur naturally in an oxidising atmosphere. There might be some other minerals but metals specifically tend to be rare in nature in elemental form and the ones I can think of found in elemental form all have extreme melting points.
https://www.lenntech.com/periodic-chart-elements/melting-point.htm
Closest on this list is Zinc, which melts at 420 C but it is very reactive at that temperature especially to acids, its definitely not found naturally as a metal. Tellurium melts at 450 C but it is extremely rare in the Earths crust so it seems unlikely Venus has more, and its not really a metal either. This is only elements, not alloys or metallic-looking compounds, so theres lots if options still but I dont think its a metal. I saw somewhere that it could be pyrite FeS2.
Costa Rica’s Poas has recently above-average activity. On 21st April it did a 4km high ash plume. Do we see the biggest possible activity of Poas or can it do worse?
https://www.youtube.com/watch?v=VdSG6q3b7As
The ash cloud reminds a bit to Grimsvötn’s black clouds, but smaller. The magma of Poas is Basalt to Dacite, but the black color of the cloud indicates that it a possible injection of hot basalt caused the eruption.
At a guess:
1. The Atla, Beta, and Phoebe Regios are atop mantle plumes. Hence the (relatively) young volcanism there as well as the overall uplift of these regions.
2. There’s a very thin crust directly atop a mantle that does the same kind of lava-lamp convection as Earth’s does, with crust just wrinkling up over downwellings and rifting over upwellings. In the wrinkle regions the bottom “melts” into the mantle (loses distinctiveness) without subduction. It’s “almost a naked mantle”.
3. There are activity cycles in the upper mantle, with the last period of high activity half a billion years ago, perhaps analogously to what drives the supercontinent cycle on Earth (but with half the frequency or so).
I wouldn’t bet actual money on these, though.
I wants to live in a cloud city on Venus certainly something like a floating city the size of many kilometers with full scale industrial production and remote surface – to station mining. The livable zone in temperature is in middle of the cloud decks, is the Venusian clouds anything as opticaly dense like Earths water clouds are? or are they much more like a thin haze thats very extensive yet with a visibility of many kilometers?
https://www.vedur.is/skjalftar-og-eldgos/jardskjalftar/snaefellsnes/
Still lots of quakes at Ljosufjoll, and still following the same line as that swarm a while back. Looks like that event was an actual intrusion, so the eruption eventually might not be in the mountains but on the plain at the base possibly.
Anyone else think we might see an eruption at Bardarbunga (or more likely on one of it’s rift zones) sooner rather than later? It’s been hyperactive the past year or so meanwhile Grimsvotn which had seemed the closer has went back to sleep.
Our in-house Bardabunga expert tells us it is getting ready for another M5, part of the recharging of the magma chamber. It is hard to tell whether it is close to erupting. Nor is it clear that we would know if something stays underneath the icecap! At the moment, this is the ‘normal’ behaviour. No promises though.
I fully agree. It’s very hard to say if it will erupt tomorrow or in several decades from now. What’s clear is that it’s currently inflating at a very fast rate. Horizontal movements of the closest GPS station KISA is on the order of 4-5mm per week (and accelerating). That’s on par with some of the stations near Svartsengi. On the other hand, there was a similar period with many M5 quakes in the 1970s, and we all know that it took a few more decades before anything happened.
It looks like the next M5 could be very close.
Maybe a few decades off from a Veidivotn rifting event then, which might involve eruptions at Torfajokull and/or Hekla too. And it also might be related to Reykjanes too given Hekla and Torfajokull are basically on the other end of the Reykjanes fault. Not causing the eruptions, but common tectonic movement.
Paper might be interesting for some authors/commentators here:
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JB029566?af=R
Also from this paper:
Thank you, Denaliwatch, I’m slowly digesting as much as I’m able.
“complex interactions”, haha yes, that sums it up.
I’m constantly frustrated, because my great curiosity and wonder about the cosmos totally exceeds my IQ, I think it’s in single figures.
Then there’s the dyscalculia, doh!!
My ability to retain and recall facts (while in education) was always limited, ageing compounds that. Fighting Dunning-Kruger.
To me, people on VC seem like gods. 🙂
No need to be frustrated. Be glad that this staff interests you.
And yes, Surtsey will go, unless it erupts again.
Everyone knows something other people don’t, or has a question to ask that others hadn’t yet considered. Everyone is welcome and respected. VC is a shared hobby – not a competition
Now that is a big pile of Reykjanes moment tensors! Mostly strike slip, along the plate boundary, but some graben formation/dike intrusion quakes too, around (where else?) Svartsengi. What do they infer from all of that? Is Krysuvik likely to go next (there is a big green normal-faulting one located there), or will it continue to domino west toward Eldey (I see another normal-faulting quake near the west coast, and more closer to Svartsengi, near Eldvorp) or something?
This is (WAS!) pretty
Jolnir Island, belonhging to Surtsey in 1966. Beauty vanishing.
I suppose Surtsey itself might eventually erode away? 😪
I absolutely like the process of the seabirds fertilising and bringing vegetation. That must be a wonderful botanical study.
Sea level rise will get to it first, I think. The cores of these islands are palagonite tuff which is basically natural concrete so much harder to erode. Surtsey would probably last millennia, although only looking much like it does now for maybe a century longer at best.
The slow “inflation part” of Episode 19 on Kilauea began yesterday:
“Kilauea Message 2025-04-27 19:49:20 HST
Weak spatter bursts began from the north vent just before 6:50 pm HST tonight.”
The steepest inflation on the summit has Kilauea Iki’s station now. UWD (Halema’uma’u) has had a concave (not conclave) development. SDH has relatively flat inflation.
About 2/3 of the way to recover E18, so E19 might start properly in a couple days, around a week after E18 and mid this week. Some point this week anyway.
The vents look very active. Has the overall inter-episodic activity increased?
Here is very young lava flow sheet on Mars this basalt is completely without impact craters, without erosion and without dust. Its likey very young even if erosional processes on Mars are much much slower than on Earth with its very thin atmosphere, lack of rainfall and biological erosional processes. This lava flow unit coud still be just a few million years old or even much less than that even its fresh apparence is indication of youthful age
Yes it looks very obvious against the background. Maybe it doesnt have the heat to do continuous volcanism but Mars is clearly not a dead planet. Although no doubt its most active years are long ago still. Venus looks the same stage based on Hectors findings although I expect that is just waning from the last big resurfacing, rather than actually dying. Venus will flood itself again in future no doubt probably several times more until it ends up in the Sun.
Where is this spot on Mars exactly?
“Where is this spot on Mars exactly?”
Only the Cerberus Fossae lavas (that run all the way to Amazonis Planitia where they form a lava sea) look this young in Mars, so it must be somewhere around there. They are very big, many tens of thousands of cubic kilometers, possibly in just two brief outbursts.
Cratering is the best way to get a handle on the youth.
This lava flow is likey a unit of the Athabasca flows that is very likey. These gigantic lava flows are sourced from the Cerberus Fossae rift dyke system that likey acts as a litosphere pathway for upwelling magma. The InSight lander measured many remote earthquakes from this region on Mars infact most of the seismic activity it saw it recorded from Cerberus Fossae an indicator its still an active system with huge ammounts of magma present perhaps a few tens of km down it maybe the easiest place for magma to erupt on Mars at present.. the complete lack of geothermal activity in Cerberus Fossae likey means the magma is quite deep down at current
I dont think geothermal is a reliable indicator on Mars, water wont stay liquid for very long and the rock is probably too cold and dry near the surface.
Cerberus Fossa is probably also a radial rift of the Elysium volcanoes, which is probably where most of the magma was. But if it is still moving now that probably means there is a bit more to it than that, and maybe some of the eruptions are directly from it. Maybe not another flood lava but if those supposed 50,000 years old eruptions on the rift are actually really that age it could and probably will erupt again in the nearish future. It is probably the most active part of Mars, certainly the youngest rift.
A youthful tephra deposition from a small sub fissure from the same system: this coud be the youngest all Cerberus Fossae eruptions maybe only a few 10 000 s of years old likey it was a short lived very gassy lava fountains the produced lots of dark basalt spherules
Sure. But you might have at least three meteorite craters under the fissure.
This picture has nothing, no location given, no scale. The question is whether we would see small meteorites at all. Large meteorites with the size of ~ 3 miles are thought to hit Earth at an average of 20 million years. The last object of 6 miles and more hit Earth at the CT event. As Earth is hit by bigger objects that rarely the question is whether the frequency on Mars is even lower due to the small size.
It seems higher as Earth is covered to ~ 70 percent by water and has much more erosional processes, subduction and plant growth, so the history of the meteorites/asteroids on Earth is and will stay incomplete.
Given that bigger meteorites are rare and might miss Mars more frequently than Earth this volcanic field can be very old.
It might also be necessary to consider the orbit of Mars which is about twice as long as the orbit of Earth around the sun.
So as long as this picture has no data whatsoever it is a freshly painted garage that became wet, sorry, Jesper.
Its quite small for being a marsian volcanic feature but bigger than the Holuhraun lava flow its about 30 kilometers long in image maps and nearly completely lacks small craters so its very youthful, even the eruption tephra have not rusted yet, it remains black its a very youthful feature
Let us say hypothetically that this volcanic field is 9-15 million years old – that would be the age of the Aconcagua volcanic complex. We would not say though that the AVC is “active”. We call it extinct.
So it seems very far-fetched to me to create an active planet out of that field.
There are more asteroids near Mars too though, not to mention the main asteroid belt not too far away. And the atmosphere isnt going to stop most of them like it does on Earth. Its the opposite of Venus which has a thick atmosphere and there are less asteroids there than around Earth and Mars.
Mars is smaller, true, but I dont know if gravity has much to do with impact frequency at least directly, asteroids already typically move a lot faster than the escape velocity of most of the planets. I think impact frequency is just how many things are nearby that can collide. Mars has more than most planets.
I wonder how this might affect the crater counting on Venus actually. Maybe most of Venus surface is older than estimated, while Mars is younger.
Its simply impossible for an object thats as large as Mars are to have cooled yet it does have cooled alot more than Earth have due to its smaller mass but its still hot inside and most of its central core appears to be liquid in InSights results even if core temperature should be quite a bit lower than Earths lower pressure and high sulfide content in the iron likley explains why its liquid lack of magnetic field is due to lack of iron motions in it. Mars astenospheric mantle part is certainly much deeper down than Earths are but it maybe just as hot as our own
https://www-vulkane-net.translate.goog/blogmobil/santorin-forschungen-bestaetigen-magmaintrusion/?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp
Santorini symposium.
I wonder if they will or are using DAS.
Last paragraph, reminds of the heavy responsibilities of these scientists.
A Search for Planet Nine with IRAS and AKARI Data, (submitted on 24 Apr 2025):
https://arxiv.org/abs/2504.17288
“First, we estimated the expected flux and orbital motion of P9 by assuming its mass, distance, and effective temperature to ensure it can be detected by IRAS and AKARI, then applied the positional and flux selection criteria to narrow down the number of sources from the catalogues. Next, we produced all possible candidate pairs whose angular separations were limited between 42′ and 69.6′, corresponding to the heliocentric distance range of 500 – 700 AU and the mass range of 7 – 17 Earth masses. There are 13 pairs obtained after the selection criteria. After image inspection, we found one good candidate, of which the IRAS source is absent from the same coordinate in the AKARI image after 23 years and vice versa. However, AKARI and IRAS detections are not enough to determine the full orbit of this candidate. This issue leads to the need for follow-up observations, which will determine the Keplerian motion of our candidate.”
Interesting, the ladt thing I saw about planet 9s expected properties are that it is maybe only 5 earths, but then without seeing it its kind of pointless.
7 earths is in the weird zone where it could be a solid or fluid planet. It also could be a planet that is mostly made of volatiles but is solid because of the temperature too, so like a gigantic Pluto. If it is above 10 earths it probably has no solid surface but like Neptune and Uranus it probably does have a distinct atmosphere as opposed to a gradient of density like Jupiter and Saturn. Ice giants arent just tiny Jupiters, most of the mass of Neptune and Uranus is probably in nitrogen, carbon, silicon iron and especially oxygen, all as hydrides or oxides even though the majority of atoms are hydrogen and helium. We really need to send something out there again.
It will be exiting if this really is planet 9, a historic discovery for sure.
The mass range in the paper is just what they are sensitive to. If planet 9 is less massive, then they wouldn’t see it at that distance. And if it is closer, they would not see it because to would move too much. Their candidate is not very strong – it is just the best they have.
It would be ironic if they find something that is too small to fit the simulations but is big enough to be a planet anyway, because that would still be planet 9 but hint of 10 and onwards.
Really, its not all that unlikely there are things as big as the Moon or even Mars way out there, which are big enough to be planets. The same is probably true of most single stars or even binary stars, with oort clouds.
I did realise after posting that a solid surface planet 9 might be impossible to see unless it is geologically active. If it is icy it will look like Pluto, covered in brown organic dust. If it has a thick atmosphere it could be brighter. This also could maybe be why it hasnt been seen yet too…
An Earth-sized planet might be visible in the optical to 3 times the distance of Pluto.
What about in the infrared though, using the Webb. Eris is 3x as far as Pluto and smaller than the Moon but seen 20 years ago.
Indeed, I had made a slight miscalculation. Earth would be visible out to 2000 au, or 50 times Pluto. But the way, Eris is on average about 1.7 times as far as Pluto, not three times. Both have rather elliptical orbits. The factor 3 some people quote comes from taking the minimum distance to Pluto and the maximum distance to Eris. But Eris can also come closer to us than Pluto, in a part of its orbit.
Héctor, Albert and Tallis have written about this Bolivian volcano, so the article may be of interest to VC readers.
Anatomy of a ‘zombie’ volcano: Investigating the cause of unrest inside Uturuncu (Phys.org, 28 Apr)
Maybe it’s a zombie, maybe not. The tip of the melting slab is right underneath, but very deep, so it’s possible that blobs of magma would only come up to the surface every now and then.
The age of 250k years, I wonder if that is the youngest eruption in the whole area or just on the mountain itself. Uturuncu might have been a sort of ‘monogenetic’ volcano, erupting and building quickly for a few millennia and then magma went somewhere else but the deep source is shared. I havent actually looked at the area but I would be surprised if it is truely a 250k year dormancy seemingly ending. Its not impossible bit it seems likely to be more complicated.
Is it an extinct volcano that has converted to a non-volcanic intrusion? F.e. a pluton like many Granite bodies in the earth.
Klyuchevskoy is in the middle of a relatively strong deep earthquake swarm, curious to see were this goes.
Russias Mount Doom very much looks like Doom for soure 🙂
Under Klyuchevskoy specifically? The whole group are probably connected deep down, although where a group of volcanoes becomes one huge volcano seems to be debated.
Klyuchevskoy and Bezymianny are both erupting now, so it would make sense one of those increases in activity. But it could erupt at one of the others, maybe making a large lava flow and pyroclastic cone somewhere. Or possibly an explosive eruption, its a bit unclear how big the evolved magma capacity is in the Klyuchevskaya group, it might only be Bezymianny or it might be wider than that.
Most likely outcome I think is a paroxysm event at Klyuchevskoy, a possible bigger eruption at Bezymianny, maybe plinian, or a significant lava flow somewhere probably at Tolbachik. In that order.
It’s mostly at Klyuchevskoy but Bezymianny is seeing some as well. I hope we get another Tolbachik eruption!
Yes it would be interesting, although its last eruption finished 12 years ago and that might be too soon, but who knows. A paroxysm at Klyuchevskoy would be a visual spectacle too, 4 km tall gravel pile adding another layer. It must be getting to a point a flank collapse is possible.
Klyuchevskoy is only 6k years old too, maybe not the volcano itself but its modern cone is. I wonder where all that magma was going before, the group as a whole is probably erupting several km3 a century, which is comparable to the larger Icelandic calderas, or to Etna. I wouldnt be surprised if it is more actually I havent done the maths recently.
Klyuchevskoy has nearly the same radiant flux as Etna, so if it’s proportional to productivity, then Klyuchevskoy alone might have a similar eruption rate as Etna, and higher if you include the other volcanoes of the Central Kamchatka Depression, that are less active but still very considerable lava producers. It’s probably by far the most active stratovolcano complex in the planet. The entire group may have formed since 300,000 years ago. And Shiveluch is only 80,000 years old. It’s still well below Hawaii and Iceland, though, and maybe also less than Virunga and Galapagos.
Something for Chad: what place or planet in the solar system do you find the most disturbing by your own feels/ opinions? Me = the abyss of Jupiter specialy so the clear cloud – less dry hotspots like where galileos entry probe fell into. You woud still be able to see a horizon in a cloud less spot on Jupiter simply due to Jupiter mass being un – transparent. And the view below your feet likey is a dark murk ( un transparent to light ) and above you woud see a clear blue sunny hydrogen daysky. These kinds of things are certainly unsettling to picture but almost everyone you ask finds Gas Giants unsettling
Jupiters fuzzy edge in a dry hotspot must look exactly like Earths shadow when Earth casts a fuzzy shadow on its own atmosphere at the evening time, thats what the doomed entry probe likey saw as it slowly sank into this cloud free abyss, sky color depends on pressure depth
I dont find any of the solid terestrial planets that extremely disturbing even if the empty wastelands of Mercury, Mars and Venus hellscapes certainly haves its terrors, Venus is quite terrible but remains a solid planet with a surface that I can have a mental grasp on… but the Gas Giants bottomless skies that gives way to a pressure cooking interior makes me feel very uneasy…
Would probably agree really, endless falling until you are crushed or pyrolysed by the heat dis way too alien. Although in reality at least you wouldnt live much longer than a few minutes at best. Interesting and maybe a bit disturbing is without CO2 building up near yiu actually you wouldnt feel as much of a choking feeling, just blacking out… So maybe a small relief from the realisation of certain doom…
Sucks there where no camera in the 1995 s descent probe but that probe where built with 1980 s technology with cameras being bulkier and heavier back then and much harder to cram into that thing. That jovian hotspot It woud be a very disturbing sight I guess a blue daysky over a
”dark fuzzy plain” there maybe was some thin high white cirrus sheets in the local jovian sky too..the deeper it sank the paler the daysky must have become under more rayleigh scattering, perhaps turning into a red sky under 22 bars ( where the probe lost contact )
If there where thin hazes in the clear jovian sky ( which there was according to the probe ) then an isolated cirrus sheet cloud blanket woud be able to cast 100 s of miles long shadow streamers into the hazy murk below this is disturbing to picture
yes, a deployable H2 balloon would also have been great iff re-entry speed could be hugely reduced “by other means”. The only feasible way I can think of would be multiple skips through the atmosphere to lose as much orbital speed as possible (where I think most of the energy resides) as slowly as possible (if that is theoretically possible). Then a near vertical fall using heat shield and parachutes until a balloon can be safely deployed. I am not quite sure where equilibrium would be reached but from albert’s last comment on this it was about the 25C height. I still think there is a good chance of life there.
Reentry on Jupiter is simply nightmarish I think you can get up to mach 220 or something! 1995 entry probe where a small bullet with a very sturdy heat shield reentry heat gets up towards 15 500 c ! even at lowest entry speeds around the equator in direction towards planetary rotation to shave off 10 km a second, Jupiters equatorial region is at the very technological limit by whats possible with atmosphere entry probes today.
Exploring a Super Jupiter or colder Brown Dwarf with entry probes will be all impossible there you have entry speeds of 100 s perhaps even 1000 s of kilometers a second in worst cases making areobraking simply impossible due to the friction compression heat
Woud be fun to see the Jovian Moons rise a morning, seen from Jupiters tropospause 0,1 bar pressure level ( If you where down in the atmosphere) Jupiters shadow woud be visible too that it cast itself on the upper atmosphere and the jovian horizon woud be incredibley distant. The jovian ammonia cirrus, cirrustratus 50 km below woud be a smooth beige – white silky plain, going for ethernity litteraly. Pale morning skies maybe a pale pleasant or just blue.. the air density is not great as far up as this, so woud be very dark blue at noon when molecule scattering is least, but more color at evening and morning. It woud be a very earthlike experience at least visualy the jovian atmosphere and very disturbing knowing there is No surface at all below your feet.
I often roams Jupiters skies in my daydreams in a gigantic hot hydrogen zeppelin, think hindenburg/ graf zeppelin but on steroids, and I woud best like it old and steampunky : ) rusty copper, brass coloured with lots of rivets visible in it, the retro golden gondola cockpit woud be a spectacular panorama over the jovian cloudscape. The whole rusty retro Zeppelin thing woud have to be absolutely gigantic to have any chance to provide any lift at all, as Jupiters atmosphere above the ammonia cirrus is not very dense, and hydrogen is very light and gravity is high, having it painted with Vantablack coud help it with solar heating and bouyancy, but then it woud be just an ugly pitchblack thing and not steampunk classy. It woud have to have a very complicated extra heating mechanism to allow it to float. Lower down in the cloud layers and below the water clouds it woud be easier with bouyancy as the atmosphere is much denser there, but visibility woud perhaps not be good at all as you are below the 3 cloud layers, and if struck by a lightning bolt thats 1000 times earths strenght the whole thing coud be history. The cold in the upper atmosphere woud suck too..
You look down you may see a altocumulus cloud field each cloud lit by the sun, below in the clear gaps there coud be another cumulus field miles below the upper layer looking hazy and less bright. Its likley possible to see 100 s of miles down into gaps, but since sunlight cannot penerate or scatter from a clear jovian depth of view ( as you look down into a clear area into the gas giant ) it woud be an unsettling dark hazy gloom. But clouds woud be very reflective and earthlike and the skies above you woud be blue like Earths dayskies, beacuse of hydrogen that woud scatter into blue, but Jupiter itself woud be a dark gloom and a hazy horizon providing No reflective clouds in a drier area. weird and scary indeed, If a cloud layer is present it woud be just like being above a cloud layer on Earth, reflective opaque surface so a ”sharp white surface” with blue sky above
But in a dry area like at the 1995 entry site where No clouds are present, it woud be a dark pit, like a grey menacing shadow If you looked down, there woud still be a fuzzy horizon as Jupiter is inpenetrable and yet not very reflective to light. The blue skies above woud look just like a sunny day on Earth
Rather disturbing 😳
Suicidal project anyway .. getting there and deploying it and the logistics are Impossible and Impossible to get out later with that gravity well of 2,4g unless the Zeppelin haves an nuclear, fusion powered escape rocket pod
Gas Giants are hellpits and not any tourist destination
Seen from inside the atmosphere at earth sealevel pressure level distant jovian thunderstorm towers may simply fade into blue on Jupiter. Thanks to Rayleigh scattering, the sky would be blue, and objects far off in the distance would fade to blue just like they do on Earth. But since Jupiter is so large having souch a distant horizon , you might not see the cumulonimbus disappear over the horizon; the towers might just fade off blue into the far distance.
Babylon 5 Season 3 episode 8, just saying! I don’t know what was scarier, the Shadow Ship or Jupiter’s atmosphere! https://halfblog.net/2013/03/02/babylon-1999/#jp-carousel-13318
https://www.msn.com/en-ph/news/national/bulusan-volcano-in-sorsogon-erupts/ar-AA1DJ2p4
Is the series of Sundhnukur slowly dying?
“Volcanologist Þorvaldur Þórðarson believes the events at the Sundhnúkagígar crater row may be fading away.” He expects at the most one more tiny eruption like the one on 1st April.
https://icelandmonitor.mbl.is/news/news/2025/04/29/i_think_this_is_the_quiet_phase_of_fading_out_says_/?fbclid=IwY2xjawJ94QNleHRuA2FlbQIxMQBicmlkETB1cUg4WWl1Zm1peDl4N014AR7fcRW_ma1Fne8MCizrAc7Ej01WHAXfBAylpOpk2qM4c44uZY_KvIg-6460Sw_aem_RWMCuJMbi8HHMuFkb2UurQ
Professor Þórðarson also changes his answer every time he gets interviewed 🙂
Inflation hasnt really changed at all, its not as fast as it was right immediately after last eruption but its still at least as fast as the average of the last year. Doesnt seem like supply has actually decreased at all in the last year. Maybe there are ither reasons to think its ending but if magma is going in then its not over yet.
Historically Bardarbunga did Vatnaöldur 877 (during onset Iceland’s Viking settlement) and Veidivötn 940. That’s only around 60 years apart. So it is able to do two big fissure swarm eruptions in a century. We can’t exclude that Bardarbunga is going to do something like this in the SW fissure swarm 50-60 years after Holohraun. But it would be after most of our lives around 2070.
No Veidivotn eruption in 940, Eldgja was around that time but that was from Katla.
There was a big lava eruption up north of Trolladyngja probably in the 1100s, that was bridging the gap between the Vatnaoldur 877 and Veidivotn 1477 eruptions. And then Laky between 1477 and 2014. Holuhraun was much smaller than Eldgja or Laki but the other 3 were pretty comparable, at least within a factor of 2-3, Holuhraun was a major event, one of the biggest historical eruptions in one of the most historically active parts of the planet…
Still, a big rift to the southwest isnt impossible, just needs a suitable parent. Katla is mysterious right now but doesnt seem a good pick to repeat Eldgja any time soon, and same for Grimsvotn to Laki. So that leaves Bardarbunga. But Torfajokull and Hekla are there too, Hekla isnt inline but is probably ready to erupt, Torfajokull is active too. They might be connected to some degree. So Bardarbunga might not need to be doing all the heavy lifting and actually start the ruft. Theres also the case it starts at Hamarinn, in which case all bets are off.
Just on average interval, a big rift eruption has happened southwest of Vatnajokull historically in 877, 939, 1477 and 1783. Thats 302 years apart on average. Its quite a bit less if the smaller rifting eruptions like Gjalp and Trollahraun or 1913 Hekla are counted but I dont think they do really. Using this would put the next one in the 2080s in about 60 years time. But its probably better to put a 50 year margin both ways, so the next rift might be in only about a decade or it might be in the 2150s… Depends on how the volcanoes themselves are more I think.
The Wikipedia list of historical eruptions on Iceland mentions an eruption of Veidivötn 940, but I haven’t found any more evidence and information about it. GVP has 940 on the list for Bardarbunga, but without data: https://volcano.si.edu/volcano.cfm?vn=373030
That eruption comes from a 1984 paper where it was dated to around 900 AD. More recent work equates it to the ~870AD Vatnaöldur eruption (e.g. https://www.vedur.is/media/jar/Bardarbunga_kafli20140825.pdf). I don’t know where the 940 date came from but presumably that date is for the Eldgja eruption, where we know that the Veidivotn eruption happened earlier – so it cold not be younger than that. It was an explosive eruption which produced some 3 km3 of tephra.
Excuse me for going off-topic, but I thought you all might like to see some video of a lava field (Ḥarrat Lunayyir) located in the northwest of Saudi Arabia. I follow a Dutch motorcyclist, Noralys (Itchy Boots is her channel), on YouTube. She travels the world alone by motorbike. From 5 minutes into the video to about 10 minutes in, she has amazing footage of Ḥarrat Lunayyir, which reminds me of a scaled-up version of Fagradalsfjall. Sorry about the massive URL, but I have no idea how to shorten it.
In there a graph with eight pics from 31 Ma till 10 million years in the future (this an imagination).
https://www.volcanocafe.org/volcanoes-of-saudi-arabia/
Thank you. Of course, it’s been covered already.
Thank you for posting. Some good memories brought back.
I’ve walked a little in the area and it’s truly beautiful. At the time I was ignorant of the geology.
I planned a bike ride to UK having met someone who had done it before. But there was too much politics on route to get permission.
Always regret it as it would have been nice to add to my list.
She is really tough. Impressive film, like it a lot, thank you Gabrielle.
I noticed at Kilauea especially for the last few months this year, there have been more small earthquakes along the ring fault if the 2018 aldera,at about 0.5-1 mile down. They arent numerous, and I havent checked what type but I wonder if the calsera fault is slipping a bit like at Bardarbunga, though far smaller scale. Its either that or maybe the weight of new lava combined with an open vent means the magma chamber roof isnt supported so is slightly sinking, again very small scale.
It might just be nothing though, but I wonder if maybe as the caldera fills if other vents coukd start opening around the rim, maybe without the typical seismicity of a fast dike intrusion. The last time the caldera overflowed there were probably many separate centers of activity at various times over the at least 500 years the summit ovefflowed. Only the two youngest ones of which are obvious now. Not to mention the many vents open 200 years ago, Halemaumau just being the dominant one…
UWD three months tilt shows saw tooth pattern:
The north vent has begun spattering, and the south vent is glowing strongly:
Krafla showed a similar saw tooth pattern, but with longer waves:
https://volcano.si.edu/volcano.cfm?vn=373080#bgvn_198204
Yes its very similar, just different scale and time. I think E19 will be in the next day by the looks of it
Krafla shows that a series of short episodes can lead to major effusive eruptions in the end. With July 1980 the eruptions grew in size. Before the eruptions were minor like Kilauea’s SWRZ 2024 eruption or Sundhnukur’s 1st April 2025 eruption. Before July 1980 most Krafla eruptions looked “accidental” like the tip of an iceberg of an intrusion.
July 1980 to 1984 the eruptions were “real”, surface oriented eruptions.
If we look at this example of Krafla, there was a lot of magma accumulation 1975-1980 that didn’t reach the surface during the five years. Is Kilauea currently in a similar mode? Do the episodes hide a magma accumulation that exceeds the current lava output? Can later stages push out the remaining magma?
Kilauea Iki in fact did a similar behaviour like Krafla: After the last episode on 21st December 1959 “far more lava was stored in the shallow reservoir beneath the caldera than when the eruption began.” https://pubs.usgs.gov/pp/0537e/report.pdf
Was the Kapoho eruption the location where the remaining Kilauea Iki magma erupted? There was a major summit collapse in February 1960, smaller than 2018, but similar mechanism. This looks as if the 1959-60 period was a mixture between the 2025 episodes first and 2018 second.
Kilauea is like a lava geyser, the saw-tooth pattern is only a loss and recovery of pressure causing deformation, not a specific cause.
Also relates to behavior too. Kilauea in the last 5 years has almost erupted the same volume as the whole Krafla Fires as it is, just a lot slower and often continuously. It will end in a major eruption eventually but that event might end up being this eruption lasting decades and overflowing the caldera. Or a lower ERZ eruption…
I don’t think the east rift zone will see any activity anytime soon, especially the lower part. I believe the LERZ (including the submarine part) acts as a safety-valve, for when Kilauea fails to erupt sufficient lava at the expected sites (caldera, UERZ, MERZ, upper part of SWRZ).
Before 1955 LERZ, Kilauea had basically been accumulating magma for three years since its 1952 reactivation. The HVO notes (https://www.usgs.gov/volcanoes/kilauea/science/kilauea-1955-lower-east-rift-zone-eruption-lower-puna) that seismicity remained high in these three years and tilt had continued to increase despite a four-day eruption in May 1954; with August that year marking the month where tilt was at its highest level since 1924 and nothing in the meantime which relieved pent-up pressure.
Although there was copious effusion during 1959 Kilauea Iki, there also was a significant drainback after each episode. As you may have been able to see on the tilt graph after the first episode of the current (2024) eruption, tilt continued to increase despite the drainback, which resulted in a net positive tilt when episode 2 happened. This evidently must also have happened during the 1959 eruption, as by the end of the last episode, more magma had accumulated than left the system. That’s another case where enough lava failed to erupt at the expected site.
Ahead of 2018 LERZ, the lava lake level at Halema’uma’u increased in height (ultimately resulting in overflows), D/I cycles notwithstanding, as a result of, I recall, an intrusion, yet no change in effusion rate occurred. A surplus of magma had accumulated, and despite the new fissure on Pu’u’o’o’s flank which was later discovered, magma found the pathway to the LERZ easier.
In all three cases, this resulted in an eruption at the LERZ, which, for lack of a better term, “reset” the system, as ahead of each the mantra is “inflation with no way out”. I strongly suspect each of the other (pre-)historical LERZ eruptions resulted from similar conditions. How long those need to last exactly ahead of each “LERZ reset” I don’t want to put an exact number on, but I suspect weeks (1959 Kilauea Iki) to decades (see the persistent lava lake despite infrequent drains in Halema’uma’u before 1924, but, if I may, I also count 2008-2018 to that, as the lava lake slowly rose during that time). I wouldn’t rule out that different modes of activity have different thresholds for when the safety-valve is triggered.
That Maunaulu didn’t end in a LERZ eruption in 1974 likely had to do with magma finding a way out elsewhere – initially at the summit (which ended the eruption at Maunaulu), then again the summit, followed by the SWRZ. Of course “catastrophic deflation” following the 1975 earthquake (HVO’s own words, https://www.usgs.gov/news/volcano-watch-eruptions-end-will-come-slowly-submitted-title-mauna-ulu-eruption-1969-1974) also helps prevent LERZ eruptions, a reset in its own right.
Back to the present. As the overall trend with the current eruption is deflation, I don’t think we’ll see a LERZ eruption anytime soon, in any case not until the net deflationary trend is reversed. Even then it’ll probably be months to years, assuming an open vent system remains. Based on pixel counting of the UWD tilt graph (take that for what it’s worth) ahead of episode 18, Kilauea overall had run a net deflation of approximately 28.8 µrad. Additionally, summit GPS stations indicate vertical is still below the level where 2018 LERZ was triggered.
What is the influence of the Earth-Moon system on Earth’s volcanism? If we assume that the Earth was a lonely planet like Venus, would volcanism and geology be very different?
The Earth-Moon system was probably created by a monster impact event by a planet-sized asteroid. This probably also changed the speed of Earth’s rotation. How did this event influence the rotation of Earth? Would a slower or faster rotation cause a different geology and volcanism? This event was 4.5 billions (milliards) of years ago during the Hadean Eon
Also, somewhat related question: Can a tidally locked planet have a magnetic field (dynamo), if the rotation rate (in this case also the length of year) is otherwise fast enough. And what is fast enough? A few earth days?
My unfounded guess: It won’t, if it’s tidally locked to the star the local magnetic field should be dominated by the star’s magnetic field. Short rotation periods would mean bigger stars or close orbit.
Thing is, Venus and Mars show that a magnetic field isnt necessary to keep an atmosphere. Mars has only 0.3 g and still holds one, Venus is 0.9 g and obviously does too. Titan is only 0.13g and it holds a nitrogen atmosphere denser than our own, although it obviously isnt in the habitable zone. So maybe a habitable tidally locked planet could still be a thing, although it would need a thick atmosphere that isnt super insulating, which might be hard. But a planet with 1g or more should be able to hold an N2/O2 atmosphere even in the solar wind, for billions of years. Although it might not have a lot of water left after that long, but the night side could be all glaciated and provide storage as ice.
I guess the bigger problem is the only stars small enough to have tidally locked habitable zones are red dwarfs which tend to be very active. That is what is expected for Proxima b, that it is probably pretty barren and has little atmosphere. But until we actually observe it this is still only speculation, maybe flares are way less damaging than expected and so tidally locked planets with atmospheres and water are totally possible.
Thank you. Of course, it’s been covered already.
But without any local video! It is a nice addition.
https://youtu.be/Zmk9ezTVoeo?si=LZrwel9dfvlB2-_B
Video from GeologyHub about Yellowstones new youungest eruption, as well as where it actually was. Its not where I thought and a lot smaller but still interesting.
HVO says the tephra layer here is 2 meters thick, about 500 meters from the vents. A 500 meter radius cylinder 2 meters tall is 1.5 million m3, and this is ignoring tje much thinner but wider blanket further out, or the much thicker tepgra pile inside the caldera (many meters, tens even at the cones).
So its safe to say this is at least a VEI 1, probably a 2, possibly even a 3. Its not much exactly, but goes to show effusive eruptions can actually have a VEI number even with typical hawaiian style activity, in Hawaii… 🙂
Funny criticism of the planned Mars colonies, the Martian soil is really full of nasty chemicals which makes it difficult to grow crops and the sharp Martian dust wears down machines and airlocks functions, being outside without a spacesuit is impossible. I hope Elon Musk understands what he is getting into. It would be really fun to force both Elon Musk and Donald Trump to work on Mars as farmers and building and maintaining pressurized modules and recycling their crap and recycling other waste.. I really don’t even think that the porcelain tudexo figures that is Donald Trump or Musk ( who gets everything fixed for them ) even knows how to use a microwave… or fix a broken screwdriver 🙂
https://m.youtube.com/watch?v=uqKGREZs6-w&pp=ygUXbWFycyBob3JyaWJsZSBrdXJoZXNhZ3Q%3D&fbclid=IwZXh0bg
The moon is a better place in so very many ways.
Well, almost all except for day length in fact.
But not quite the same cachet, I suspect.
Moon is worse in some ways, there overall even less useful water and volatiles on the Moon, there is even less gravity to slow bone and muscle degradation than on Mars. Both are hard places to settle before industrial factories are set up that can use the local geological materials to produce home – made goods on Mars and the Moon.
Musk and Trump struggling they be growing stunted foul tasting greens in perchlorate-contaminated ‘soil’ in some habitat in a remote Martian crater and they breeding small foul stunted fishes in aquaponic ponds …the hilarious idea seeing them collecting their crap and processing it on Moon and Mars recycling feces becomes gold commodity
The fishes in the tanks are small and stunted, bony, nearly inedible and dart around in the tanks like crazy while a tired Trump waters the stunted vegetables. Well on Mars the habitats needs to be served and maintained all the time there is lots to do and there is lots to worry about.. all the time…
Perchlorate is a potental source of oxygen that doesnt involve electrolysis, so not a bad thing really. Its also easy to remove by distillation like with seawater, and with the oxygen removed you get calcium chloride which is non toxic. It also might be usable for making rockets, its a lot easier to get to orbit on Mars so not strictly necessary to use really high tech rockets, solid boosters would work at least early on. I guess its a problem still but its probably not a problem by the time a mission actually happens.
Biggest problem on Mars excluding actually getting there is the low gravity, eventually future Martians wouldnt be able to walk on Earth without assistance. But there is a lot of water on Mars, and adding carbon to the dirt makes it usable, so its not necessary to bring along all the soil.
Much as Elon Musk has fallen to the dark side in recent years, I used to be a big fan back in the Covid years and back then he sounded much more optimistic and actually interested in his companies, and SpaceX has no public stock so he cant be accused of stock pumping for early Starship goals, although maybe fairly judged on what he thought was a good enough rocket at the time…
I still think an electric car would be a great Moon or Mars rover. Range is no issue moving at walking speed with a solar panel and that is still way faster than existing rovers which move like 50 km a decade… the Apollo moon buggy was literally exactly this, but we have way better batteries and solar panels now. A solar car with nitinol tyres and high torque motor would be a perfect rover 🙂
The biggest problem with mars is that its a VERY long was away and VERY expensive to get to in both time and energy. I am not so sure water is that rare on the moon: accepted, its not common. Ita actually quite easy to land and take off from the moon though due to its low gravity and low orbital speeds.
To get a self-sustaining infrastructure on the moon would still take millions of tons and tens of thousands of people at a minimum (could be >100k). Until that time, routine supply will be required at regular intervals, probably weekly.
If you cannot make solar panels and building materials (particularly transparent glass) cheaply on site then its a total non-started. Economically I can’t see the moon has anything going for it, or mars come to that, which is even harder.
Reality always trumps aspiration.
Imagine if Mars where a Super Earth
( impossible due to Jupiters migration and stealing of ackreation mass ) but imagine anyway: it woud completely change what Mars really is today: there woud be plenty of geological activity likley even hyperactive plate tectonics a dense atmosphere and a very strong geomagnetic field
GPS is showing continued inflation at Svartsengi. At the current rate, if conditions are similar to previous, I estimate an intrusion or eruption in about 4 weeks +/÷ 1 week.
That was supposed to be a new comment;P
Haha.. Trump and Musk that shouts Mars all the time ( are forced to to do hard work on Mars by me ) They are very busy drying their feces on Mars in electric ovens specialy built for the purpose by Nasa. It is Elons stools from a few days of collecting thats being dried 180 c at many many hours to kill active bacteria. After the oven the dried heat treated stool is crushed into a coffee like powder to fertilize the stunted percholrate filled vegetables…in the aquaponic gardens
(UWD, 1 month, live)
(SDH, 1 month, live)
These two are the usual we see so we could see if an episode is coming or not (likely is today), but they are both lower than tilt levels of the previous one. On UWD, it is experiencing plateau or deflation. On IKI, however, something odd (at least to me) happened:
(IKI, 1 month, live)
Is this normal? A sharp jump up to the same levels as the previous episode? Is this a malfunctioning or is a new phase in this episode coming? Chad mentioned something about small earthquakes near the 2018 caldera faults, so does it have any connection to this?
It could be related, the jump happened about a day ago and the quakes on the eastern ring fault of the 2018 caldera were over a period of time about the same. Although it doesnt look like it was exactly coincidental theres no other good natural explanation.
Blue line at IKI points pretty much radial to the caldera, so the signal shows the uplift slowing then releasing, which sounds exactly like what Bardarbunga is doing, but Kilauea has never done this at least not during inflation. I doubt it means much on its own but there could be changes in the making for the eruption.
Lots of fire in the north vent, I dont remember seeing any flames before other episodes. If it is hydrogen then there must be water reacting with the lava, probably the Fe2+. The last time I remember seeing obvious flames at Kilauea was back in 2022 on a live video from EpicLava, and not long before I saw it myself. But the activity now is quite different and much more powerful, theres a lot of heat flow through these vents.
This is the radiant thermal emussion of Kilauea from the MIROVA satellite. When it is only the open vents doing nothing between episodes, it is sitting at about 1 MW continuous but sometimes much more than this, as much as 100 MW all with no visible lava flows.
When there is a full high fountain, the output goes way up to around 10 GW continuous for the duration of the episode. It looks like the absolute peak is 13 GW.
I think I did see some flame before episode 18, maybe 17, although they below the rim so it’s hard to see but occasionally peek over it, unlike now where it is visible.
Yes there was always flickering light before visible lava, I always assumed it was spatter bursts but maybe it was fire instead. Both vents are pretty shallow now not the deep holes they used to be.
I should add, a 13 GW output is more than every single currently operational and planned future thermal cycle power plant on the planet, and that is the entire 100% output of all energy not just the rated electric output… Every single coal, gas, oil and even nuclear plant are all just a campfire to Pele. Only 5 hydro dams are more powerful, and the biggest one only by 2x. The amount of energy in lava is enormous.
Although the power average of the eruption might be ‘only’ 1-2 GW, which is similar to before 2018 and still a huge number. Nyamuragira has a huge open lava lake yet still tops out about the same. Lava fountains are extremely hot, as it turns out… 🙂
Hydrogen burns with a faint blue flame, as does sulfur. If you are seeing flames then it would more likely be methane and/or carbon monoxide.
or a bit of dust gets in, like sodium-containing.
Many things can colour a flame, and the source material is likely not uniform and pure.
Hekla reminding us she is lurking 😉
Thursday, 01.05.2025 10:56:16 63.994 -19.692 0.2 km 0.4 99.0 1.2 km W of Hekla
Source: https://en.vedur.is/earthquakes-and-volcanism/earthquakes/myrdalsjokull/#view=table
Usually earthquakes there are linked to SISZ, not Hekla. If Hekla does quakes, the eruption begins within 90 minutes (the time frame of a soccer match) … and the quakes probably rise from deep levels towards the surface.
Not really sure there is any difference really. Hekla in 1845 was noticed in advance so it isnt always quiet, that might have been because of its more frequent eruptions in the 20th century. And Hekla also has a deep magma chamber so a sensitive seismic network is needed to see the small pressure quakes that are easily seen at Kilauea. Which, would also erupt with minutes warning if you happened to be there when it started.
Its also a totally different story for basaltic rift eruptions from Hekla, like in 1913. Those are dikes and rifting events so probably no different to on Reykjanes. There was also a mag 7.5 quake there in 1912, which might be related. And a 7.5 is the same as 5.6 million mag 3 quakes, which is the same as 136 mag 3 quakes there every day since then… So maybe Hekla isnt as silent as it appears, in more ways than one.
Not to few of you might find this paper interesting. About the effects of the Eldgja (~900-940 AD) eruption and the Laki (1783/84) eruptions in Morocco:
“Effects in North Africa of the 934–940 CE Eldgjá and 1783–1784 CE Laki eruptions (Iceland) revealed by previously unrecognized written sources”, open access
https://link.springer.com/article/10.1007/s00445-020-01409-0
A new testimony worth taking into consideration is the Supplementum chronicarum, written by the Augustinian monk Jacobus Philippus Foresti and first published in Venice in 1483. After the election of the 20th Doge of Venice Pietro Badoer Participazio (which took place in 939), this chronicle records: “In quest’anno medesimo per alcun giorno el sole apparve come sangue”, i.e. “in this same year, for some days, the sun appeared like blood”.
I consider this a precise date as the election date of the Doge is clear.
Concerning the Islamic year 327, that began on 28 October 938 and ended on 16 October 939 CE, the chronicle reports
“and in the year three hundred twenty seven, there was the “year of the clouds”: the (veil of) clouds dwelled five days in Morocco. Through it, people could not see the Sun, and nobody could see the ground beyond the place where he stayed. People were afraid for this reason, offered alms and repented, and these clouds were removed from over them”.
The phenomenon is recorded in a medieval North African chronicle known as Rawḍ al-Qirṭās (“The Gardens of Paper”), which was written in 1326 CE (and from here onward we refer to the critical edition of 1843) and is one of the most important sources on the history of Morocco in the first centuries of the Islamic conquest.
There reports look plausible to me.
Laki
The most detailed information comes from the Neapolitan scientist Michele Torcia, who shared it with many contemporary scientists across Europe. In a letter dated 9 September 1783, he wrote (Torcia 1784)
“The darkness was even stronger on the southern coast of the Mediterranean Sea. Our coral fishermen [from Torre del Greco] could arrange nothing this year by the island of Galite and by Tabarka on the coast of Tunis. One of their barks perished after the crash with another. Letters from all provinces of the kingdom testified that the growth of this mist was gradual and the same everywhere, with the only difference that it occurred earlier and with more force in the southern regions. In short, it was strongest in the middle of summer, when no fog is otherwise known of”
All passages from the Springer Link paper.
Looks like Episode 19 of Kīlauea has started half hour ago and might be cyclic at north vent…
Yes the same episodic overflows, high fountaining will probably begin within a day of now 🙂
Its interesting how the vents seem to have different activity. They obviously start in the same place but the divergence point must be pretty deep, deeper than the point of gas evolution in the magma, so maybe over 1 km. Which is actually pretty close to the magma chamber in general. This would also explain why both vents have at times not participated in an episode but still survived longer term.
This double vent system was common in Fargradalsfjal. They are always along the rift/dike, so in a place where this dike gets close to the surface and finds a weak spot, it made two conduits. In this case, they are along the caldera edge so the plane of weakness is that of the caldera wall, I assume caused by the pressure difference between just outside (carrying much more weight) and inside the caldera. It is not that different from the constant spacing between volcanoes in Iceland (https://www.volcanocafe.org/volcano-ecology/). You would expect that the magma paths diverge at a depth which is similar (factor of 2) to the distance between the cones. So not deep at all. It is not a stable situation in the long term but seems to last well here.
Im not sure those two eruptions are analogous. Fagradalsfjall generally had pretty low effusion rate and only became episodic after a single vent became dominant, and it happened pretty quickly if I remember correctly. But both vents at Kilauea have survived despite much higher eruption rate, even though not every episode involves both including this one it seems.
To me this looks like two mature open conduits in parallel. The fact they dont really seem to mirror each other at all most of the time makes it hard to believe the separation is so shallow.
Latest
19 has begun.. North vent fountaining begun just before 21:30 HST accompanied by the onset of rapid deflation.
No south vent, even though it was glowing strongly too. Its still early but thats a big change from the recent trend
Actually it looks like the south vent is going but the webcam is so overexposed its hard to see what lava comes from where…
Yes! It looks like some of the big Mauna Ulu pictures with lava cascades
Mauna Ulu’s lava cascades into Aloi Crater were much bigger, we need to see something like this again. But for this you need a lava flow that floods an empty crater downhill. This can’t happen in the summit now, only if a lava eruption happens upon the caldera rim:
https://home.nps.gov/media/photo/gallery-item.htm?pg=6496027&id=0bfdbf84-db56-4a3b-b5d6-321196d68d90&gid=81D6CA00-BCDB-4C54-917E-1B86D6842611
https://www.nps.gov/npgallery/GetAsset/0bfdbf84-db56-4a3b-b5d6-321196d68d90/proxy/hires?
Live from a different angle, it is more clear that the north vent is tge only one erupting right now.
https://www.youtube.com/live/7eLxAvGg-1Q?si=5k0zdtN3IPIp_x1_
Finally a new map with volumes given too. 87.5 million m3 erupted before E19 started today. So each episode is on average a bit under 5 million m3. All of this on only 1/3 of a year, at this rate by Christmas there will be over 250 million m3 of lava erupted, and a bit longer the 2018 caldera will be overflowing by its 10th birthday…
Speaking of overflowing calderas, it looked like the north vent might’ve broken a bit of the wall during this eruption and parts of the lava are going into the south vent, as shown earlier in this live stream when he was in person (Doing Hawaii):
https://www.youtube.com/live/aatXDjvvKYY?si=8CanmPqLFjDRLAt-
Looks like, some time in the future and if the eruption goes on like this, two vents might eventually form one crater…
(S2 Cam, live)
Some of the lava might still be overflowing into the south vent. It might’ve even built a wall around the vent itself…
It is 87.5 million m³ in ~four months (End December to End of April). Can we compare this with the rate of Pu’u O’o and Mauna Ulu?
Mauna Ulu I lasted 29 months (1969-1971) and had a volume of 190 million cubic meters. In a month this would make on average 6.55 million cubic meters.
If we divide 87.5 million m³ through 4, we get on average 22 million per month. That’s more than 3 times of Mauna Ulu’s rate, if I have calculated correctly.
Pu’u O’o lasted for 35 years (~420 months) with 4.4 cubic km. This was on average 10.5 million cubic meters per month. Half rate of the first four months of the current Kilauea Summit Eruption.
Of the big eruptions only 1840 had a higher output rate than our eruption. 1840 did 190 millions in 26 days. So around double volume as our current eruption within one month. Or the whole Mauna Ulu I volume in one month.
In fact since 2020 we see a clear development of summit eruptions towards higher rates. Each eruption had a higher rate than the previous one. The September 2023 eruption (six days) had a volume of 19 million m³. On a monthly level this applies to 95 million m³ per month, so close to our average rate.
Maybe the rift zone intrusions after September 2023 diverted magma flow there, so the summit couldn’t continue the path of summer 2023 for a while, but in December 2024 the path was back.
HVO considers the 2018 eruption separate from Pu’u O’o, although nit a distinct eruption in terms of being separated in time. But 2018 was much faster than 1840. 1960 was also close to 1840 too, and bigger volume.
The ongoing eruption is now probably about 91 million m3, in 130 days. That is an average of 0.7 million m3 a day, or 8 m3/s. The supply rate is a bit less as some of the volume is overpressure, but its probably still around 6-7 m3/s.
Pu’u O’o erupted 4.4 km3 in 12901 days, about 4 m3/s average. But there was net deflation for that eruption so the supply was a bit less, Pu’u O’o only saw sustained inflation in 2007 and in the 2010s which is where supply was higher than eruption rate. Mauna Ulu was 347 million m3 in 1885 days, or only slightly over 2 m3/s. But there was net inflation during the eruption and a lot of gaps so the supply rate was higher than this. It was probably still less than Pu’u O’o but fairly close.
3 m3/s is 94 million m3/year, 4 m3/s is 126 million m3 a year
Neither of them is anywhere near the supply and eruption rate of today. And this supply didnt just start, it has been very high since about mid 2023. Far from Mauna Loa taking over in 2022 it looks like Kilauea now has total dominance of all the magma…
If you ask me I think the Pahala magma has finally started escaping, it could have been building up for centuries. Maybe that is what happened to fill the caldera last time, a very steady base rate that isnt controlled by the cyclic alternation between Kilauea and Mauna Loa, or other variables. Pu’u O’o kind of got this from Kilaueas summit magma chamber itself, but the potential today is far greater if true.
I also would like HVO distinguish between Pu’u O’o 1983-2018 and Leilani Estates 2018. Leilani Estates was driven by draining and collapse of the summit and Pu’u O’o reservoirs. It was on low altitudes, where it’s easier for the volcano to release volumes of lava. Low ERZ eruption can be very voluminous. They can use stored magma from elsewhere. 1960 was another example with 1/4 km³ within 36 days.
1840 was a very short eruption of 26 days. It was an “all ERZ” eruption beginning in Alae Crater and erupting along the whole ERZ until low ERZ. There also was some subsidence on the summit, but not as dominant as 2018.
I forgot to mention the SWRZ intrusion in February 2024. How large was it? If I remember correctly it was the most voluminous event since 2020. Its rate was probably also higher than the current eruption rate.
https://www.usgs.gov/media/images/february-3-2024-summary-map-recent-unrest-kilauea-volcano
https://www.usgs.gov/observatories/hvo/news/volcano-watch-another-intrusion-southwest-kilaueas-summit
Higher feed rate than the current eruption rate but no way it is more voluminous, I saw 40 million m3. Its the biggest event outside the caldera after 2018, and in 2023/2024, but the filling from 2020-2022 and this year is much more.
“January-April … a minimum of 50 x 10,000,000 m3 of lava had been extruded since eruptive activity began on 3 January.” https://volcano.si.edu/volcano.cfm?vn=332010#bgvn_198305
The first four months of Pu’u O’o had ~50 million m³, so a lot less than our present eruption.
About half, so consistent with the supply rate being close to double now too.
What a ridiculous set of units/number expression. There is a scientific (indeed engineering and domestic) measuring system that states that measurements go in powers of 1000: SI =
p,n,u.m (0) k, M, G, T etc. This is to allow easy comparison.
50 x 10,000,000 m^3 fits neither the antique centi (powers of 100 scale) nor the SI scale.
In a land-based scale its 0.5 (km)^3 or 0.5 Gm^3 or 500 Mm^3.
Personally, I prefer (km)^3. Alternatively, this covers a square of land 10km on a side to a depth of 1/2m.
Its quite interesting really how an apparently huge lava flow over a large area is often quite a modest volume in (km)^3.
Sometimes they didn’t write 10,000,000, but wanted to write “10⁶ m³”. But usually the keyboard only has the exponents ² and ³, so they have to use the ^ for declaration of exponents.
As humans we have short memory. We see it with weather disasters as well with volcanoes. So for us each volcanic eruption is a very subjective and personally important event. It’s always a bit difficult to compare it with eruptions that we didn’t observed. The historical experience of Pu’u O’o was, that it was a big volcanic event that covered a big area with lava in a short time. We remember well the pictures of burning rainforest. But the subjective experience lacked the comparison with past eruptions which did higher rates. 1840 was very distant to Pu’u O’o, but much higher rate.
Its not that bad, its understandable to those who arent well experienced. 6 zeros is a million, and 5×10 is 50.
Part of the job is being able to explain the results to people who dont know what the jargon is. There is a bit of history of misunderstanding between HVO and the locals, especially in 2022 where they said Mauna Loa isnt erupting on its southwest rift zone, despite part of the fissure being outside and southwest of Mokuaweoweo. Technically they are right, the SWRZ starts at the pit craters, not inside Mokuaweoweo. But there definitely was a fissure open above the Kona coast, and it could have been destructive, many people took it as a gaslighting attempt basically… 2018 was its own set of problems…
If you want people to understand then stay away from unusual large units and random large numbers. People/humans struggle with this.
1 (km)^3 doesn’t sound much: misinterpreted.
An area 33km on a square 1m deep is comprehensible.
An area 10km on a square 10m deep is too.
I would suggest using either of the last two to express lava amounts.
Random mixes of unsuitable volumes (like litres) and random large numbers like units of 10,000,000 m^2 do not enhance understandability and is really just lazy.
It is not just volumes. I remember being in Poland during the hyperinflation when the money was counted in thousands and more. When there are so many zeroes on a banknote, it is hard to tell the difference between 500 and 5000, or 5000 and 50000. I would often hand over a bank note to have it returned as being the wrong one. The level of honesty was such that the bank notes that were too little or too much were handed back in equal numbers. That builds trust in a country.
Dear Albert,
it is not possible to make a useful comment on your post.
A fitting end to a sub-thread.
However its true that the poorer you are, often the more honest you seem to be.
Looks like there was a pause 5 minutes ago or it’s over (episode 19).
Interesting how the volcano can do so high rate with so many pauses. Maybe an example for good human workflow. Pu’u O’o during the first four months did less volume with fewer pauses. January to April Pu’u O’o did three episodes (2024-2025 19), so only two breaks (2024-2025 18).
Our eruption is 74% stronger than the first four months of Pu’u O’o.
So if’n I’ma cyphering right smartly with’n my 5th grade edamacation: 87.5 million cubic meters = 0.0875 km3 / 4 months * 12 months = 0.2526 km3/year.
In Stock Market Technical Analysis we would say that looking the 1 year chart, after strong growth in the first half of 2024, the UWEV hit stiff resistance starting with the July 2024 eruption out on the SWRZ. Resistance was retested in September with the MERZ eruption. With the 1 year line in the tephra clearly drawn, the UWEV attempted a third test in search of a breakout.and found it in early December when crowd jumped on the bandwagon as buying pressures burst through resistance. This turned out to be only the Head of a suckers rally as the left shoulder of the Head & Shoulders pattern was already in play back in September. However, former resistance quickly turned to firm support as selling pressures were relieved and stability in the chart resumed. Looking at the 90 day chart of EWEV in 2025, we see a slight positive slope in the 90 day moving average with about 3 or 4 centimeters of growth during that time.
The magma supply number is probably a little higher considering the slightly net positive inflation since the eruption start and whatever small amount that is trickling into the rift zones.
?fileTS=1746209129
The MLSP way up top Mauna Loa maintained slight inflation all the way up to March until it flatlined.
?fileTS=1746209173
I think we have all just witnessed the long term peak supply capability of the Hawaiian plume. Where on Earth and how much is the number 2 on the list for magma supply rate production within a 100 kilometer diameter? I wouldn’t think its anywhere close to a quarter of a cubic kilometer per year…
Iceland probably has similar magma generation rates, but most of that is plutonic and the volcanoes dont get supplied with that much. That might also be true of some other places.
But that shows the other thing about Hawaii, its eruption efficiency. Half of the magma generated in Hawaii actually erupts, and its much more than that if there is an overflowing vent, its nearly 100% now. Most other highly productive areas are rift zones that trap magma, but the rifts in Hawaii are only part of the magma storage of the volcanoes not basal to them.
The quarter cubic kilometer of magma is only the erupted part. The rest is down yonder in the Pahala sills. Didn’t you give a figure for that volume once?
I would propose that if you bring into the equation plutonic magma in Iceland, it is fair to include Pahala on the other side of the equation for Hawaii.
So which produces more magma in a 100 kilometer diameter?
Iceland MAR & hot spot including eruptive, intrusive, and plutonic magma or,
Hawaiian plume including eruptive, intrusive, and Pahala magma production…
I think once I calculated that the volume of the whole Pahala swarm complex us like 1000+ km3, and that even if 1% of the magma there erupted it could double the output of Kilauea. But the actual location that most of the Pahala quakes happen seems to be along a fault line that at a shallower depth is where the SWRZ mobile south flank ends. If it is actually the same fault line that could indicate the tectonic structures in the island are deeper than just the volcanoes, and actually could go into the mantle, although theres no evidence eruptions occur that bypass the central volcanoes at least on land.
It also stands to reason that if this is a moving fault parallel to the SWRZ, then deep down is spreading too, and that means magma movement. It all points to Kilauea getting a big surge and potentially for a very long time. 1% of 1000 km3 is 10 km3, and if the supply was about 0.12 km3 anyway that is an extra 0.15 km3. It would take nearly 70 years to use up that 10 km3… It also looks pretty likely that a lot more than 1% of the magma could erupt, so there could be centuries of high activity. Or Mauna Loa could take the plume and become really active while Kilauea still has the Pahala magma feeding it, so they both erupt together.
I think the caldera will be basically gone in 10 years, and lava will be flowing down the pali before 2030. Volcano House is probably safe, that rim is a lot higher and uphill, but all of the Koae and SWRZ area could be a sea of silver lava soon. Seeing lava cascading down Hilina Pali and falling a few hundred meters straight into the ocean is a distinct possibility 🙂
I loved this comment.
Mac
How is the correct hierarchy of oceanic plumes? One propasal:
Hawaii > Iceland > Reunion > Galapagos > Canary Islands > Azores > Jan Mayen / Tristan / Eifel / St. Helena (Napoleon’s exile island)
Galapagos is definitely above Reunion. But you are also forgetting Virunga.
Mine is Hawaii, then Virunga, Iceland, Galapagos, Reunion, and the rest are hard to really put numbers on. I also dont know if there is a plume under Afar or nearby, or if that is just rifting.
Really the main problem is only Hawaii even has an easy way to calculate output, and it is 0.21 km3/year for the last few million years. Iceland is 16 million years old, about 4 km tall, and maybe half a million km2 in area with all the glacial sediment fans added. That gives 0.125 km3/year, which is only slightly over half that of Hawaii. Parts are a lot thicker than 4 km, but I think I also overestimated the area too. In any case it doesnt seem likely that it is twice this much
From that alone its pretty likely that Hawaii is quite in a league of its own, its much more active than other similar volcanoes.
I’d count the continental plumes seperately. Afar still is more continental than oceanic, but can change in future. Yellowstone, the weak Sahara hotspots and Eifel are continental plumes which are difficult to compare.
There are subduction zone volcanoes with higher productivity than weak hotspots. This applies much to volcanoes which sit on an extensional area like f.e. Etna or Krakatau.
I dont see why they should be separate, Iceland is a plume and a ridge. Actually, just the plume alone in Iceland is probably 5 on my list, it is extremely hot like Hawaii but on its own probably smaller than Reunion.
Yellowstone might actually be in the top 5. It doesnt erupt often, last was 35000 years ago and small, but the caldera does huge eruptions as standard and has gigantic heat flow that is hard to explain without a continuous magma supply and circulation.
For the full hot spot list, Hawaii is highest by quite a margin. It provides 16% of all heat flux from all hot spots. For individual volcanoes, a possible ranking is by gas emissions. That puts Ambryn, Kilauea, Bagana and Nyamuragira/Nyiragongo in the top: the order depends on whether it is measured by SO2 or CO2. Nyamuragira/Nyiragongo can’t easily be separated in the measurements so are lumped together.
Heatflow sounds like a good indicator for the strength of a plume.
Is it possible to compare the plumes concerning the combined production of igneous and extrusive rock/tephra?
Its hard to compare subduction volcanoes to plumes though, they have more volatiles. I also dont know if you can compare an evolved magma eruption to mantle supply rate, as it needs to come from a crust storage and input output isnt necessarily equilibrium like it probably is with the same magma in two connected areas.
There isn’t a single measure that fits everything. Heat flow comes closest because it will eventually reach the surface. But can be hard to measure. Volume of the volcano may include inflation purely from the buoyancy, as is important in Hawai’i. Melt production suffers from the problem that it may not reach the surface and solidify again underground. Lava production requires very long time scales to average things out, as it can vary even from millennium to millennium. Reykjanes is a case in point: for there past 800 years it was bottom of the Icelandic pecking order, and suddenly it is becoming one of its main lava producers even on a century time scale.
Hawaii actually sinks down into the mantle, the island is about 15-20 km thick in the middle the outer Hawaiian arch is the plume bulge that is then depressed, and eruptions happen out on the seafloor there too, and are maybe the biggest lava flows able to erupt anywhere on the planet today.
Iceland seems to be propped up by mantle uplift a lot more, except at its center where it is depressed by weight too. Iceland also probably has a continental component, maybe not a full base but continental fragments buried inside. Hekla has to get uts fluorine somewhere and Iceland is otherwise pretty low in it.
In the world of hotspots, I agree with Chad that Galapagos is definitely more productive than Reunion.
Afar in terms of eruption rate, is just below Reunion, given that looking at the volume of Alu-Dalafilla/Bora Ale eruptives and making guesses for the others, there’s probably about 200 km3 of lava in Afar for the last ~15,000 years. That said, there is a little additional volume in the MER and the Arabian Peninsula that can probably be grouped as the same hotspot (same swell and radial pattern of volcanism), and a lot that’s probably in the Red Sea and maybe intrusive in the form of dikes, so I think Afar probably goes over Reunion in total.
Iceland may be very powerful as a magmatic province. Oceanic crust is basaltic, so the whole volume is melt extracted from partially molten peridotite. Looking at maps of crust thickness in Iceland, including the unusually thick crust of the Reykjanes Ridge and Tjornes Ridge then the total magma production of the Iceland magmatic province is 0.5 km3/year, about 1/40th of the Earth’s mid-ocean ridge magma production. Of those 0.5 km3/year, 0.2 km3/year would be that of a normal mid-ocean ridge, and 0.3 km3/year might be attributed a hotspot origin. But only about 0.11 km3/year of productivity, which exceeds that of a normal mid-ocean ridge, falls within the emerged part of Iceland. So, depending on how the rules are set, either Iceland or Hawaii wins, both far ahead of Virunga and Galapagos which might in turn be interchangeable at around 0.05 km3/year. I’d say:
Iceland/Hawaii > Galapagos/Virunga > Afar > Reunion
Azores, Etna, and Yellowstone may be in the list too.
Our experience with Reunion is very short. Did it do larger than normal eruptions before the French colonial rule? How representative is the behaviour of Piton during the last decades?
It probably can do much bigger eruptions more regularly, theres a lot of large pyroclastic cones all over the outer slopes of Piton de la Fournaise. In historical time as far as I know only the one in 2007, 2019 and 2020 are a true tephra cone made by tall fountaining, the many other examples are more spatter cones of many sizes. But many disyal vones are not flank vents of the central system of Piton de la Fpurnaise but probably monogenetic eccentric eruptions that start down in the deep storage of the island. I dont think anything like that has happened in a historical eruption but the early centuries history was either patchy or arent easy to access in English, so maybe some if the distal cones are younger.
This map shows radiocarbon dates that show there have been unrecorded recent eruptions outside the Enclos Forque, in 1726, 1766 and 1823, interesting as there were observed eruptions in 1708, 1776 and 1800, so observation must have been very intermitent. The last time a vent opened outside was in 1998 but very small, and in 2005 a dike went outside but erupted on the inner wall within, so it isnt counted but technically should.
Based on the above, the frequency of eruptions outside is about 30 years apart, but not very consistent. Still, if you count 2005 it has been 20 years so theres a pretty good chance the next time will be in the 2030s. I dont know what happened in the 1760-1830 range to get more eruptions though, only to get none between 1823 and 1977. But it sounds a lot like Kilaueas ERZ being dead at about the same time, only to be very active later, that seems to be related to flank movement and Piton also has active seaward sliding.
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQjeMMwan3A65ovtjLUkQas-w1cCfeEup5PgD2EoRpPY_rAKxaGJILRdDDx&s=10
The last major eruption was 2007 with a big volume, ocean entry and collapse on the main summit caldera.
https://www.youtube.com/watch?v=4Tugoo77NPo
https://volcano.si.edu/showreport.cfm?doi=10.5479/si.GVP.BGVN200712-233020
The eruption history doesn’t show whether there were bigger lava eruptions than that. Two possible big events aside effusive eruptions are 1) landslides and 2) rare explosive eruptions (~2765 BC, VEI5).
I’ve also tried to check the next two volcanoes of Hawaii: Hualalai has flat deflation, Haleakala is without station. They say in the recent update in May that Haleakala is without significant deformation. How good is monitoring of these two volcanoes by HVO?
Monitoring Hualalai has the benefit of Mauna Loa’s vast of array of seismometers & GPS stations that would foretell a potential eruption with earthquakes & inflation to the Northeast.
In response to the Mauna Loa 2022 eruption, The HOK tiltmeter on the South Rift of Hualalai temporarily flashed tilt to the southeast and indicating inflation. The Hualalai eruption series prior to 1800-1801 was in the 1400s just north of this instrument.
Mauna Kea has a collection of telescopes that are among the most sensitive GPS station on the planet Earth. Even back in 1973, the seismic network picked up the 7+ magnitude quake on the East Flank that many consider a deep seated intrusion at 40 or 50 kilometers. It would be interesting to know if this possible intrusion was related to the second boiling of stalled magma at 25 km that the seismic network picked up over a period of 20 years until recently.
Haleakala also has one such instrument at the summit at the observatory. In early 2022, I remember seeing a 4+ magnitude tectonic quake on the North Flank. The HVO also does a survey campaign to measure changes at key potential eruptions sights from the East Rift all the way to the SWRZ.
As Chad has often said, an eruption on any of these 3 Volcanoes would promulgate fairly quickly with a sharp rise in earthquake and tilt but little deformation shown on GPS instruments. The best account of a potential eruption on Hualalai was described by witnesses in Kona during the 1929 6.5 magnitude earthquake and failed eruption.
https://hilo.hawaii.edu/maunakea/library/ref/1032picked up o
https://www.sciencenews.org/article/mauna-kea-volcano-dormant-tiny-earthquakes-gas-magma
The abundant olivine xenoliths in the Kaupulehu flow on Hualalai suggest it erupts very fast after onset of a swarm, within 3 days probably and maybe much faster from how recent dikes have moved in other places. That flow probably wasnt erupted in 1800, the only records of that year are the slower Huehue flow under Kona airport, which started off as a fissure eruption but became a slow pahoehoe eruption. The Kaupulehu eruption was very fast and intense, it maybe only lasted a few days even, or at least most of the lava erupted at the start.
Lots of older eruptions at Hualalai are longer lived though making lava shields and even gigantic fountain fallout cones that suggest 1000+ meter fountains…The eruption in the 1400s actually started slow and then got really intense later, it started as a maar then became a small overflowing lava shield, and then that lava lake suddenly turned into a full fountain and flooded a big area down to the ocean. Weirdly it was only a singular vent from the start, not a fissure, so the intrusion wasnt a long dike and perhaps its warning signs were different too.
Three days feels like if we’re completely blind. Doesn’t modern science help to know f.e. ten years before that an eruption is to expect soon?
Maybe an intrusion like 1929 on Hualalai would help HVO to test modern equipment during a volcanic unrest there.
How can we know then, how long the current calm state of Hualalai is going to last? Are we able to notice anything 10 years before a next eruption there as an early sign?
Are there better instruments than GPS to monitor the three postshield volcanoes of Hawaii?
Very interesting, both vents are glowing bright already, and the south vent is brighter even though it didnt erupt in E19. E20 probably isnt too far away.
And on V1 livestream
https://www.youtube.com/live/oG5zz9Sjw3E?si=-PbnQxDx1xyO-iSO
There was 7 microrad deflation with E19, so its likely E20 will be some point in 4-6 days, so not a week like before 🙂
It looks like a Stromboli situation with a magma body shallow below the crater. If it was an Andesite or Trachyandesite (Stromboli) magma, it would occasionally do Strombolian bangs. But as Hawaiian basaltic magma, it’s too peacefull for that. This changes a bit, when inflation and pressure rise enough. Then the cone(s) do some spattering which is kind of an intermediate Hawaiian-Strombolian eruption type.
Is the current eruption of Kilauea an eruption that “loads the summit”? 1975 Mauna Loa had a similar eruption on the summit that increased magamtic pressure in the summit region, that was later released 1984. 1959 Kilauea Iki did an episodic eruption that “loaded the summit” towards the 1960 eruption. I have the feeling that the episodes that we witness, follow the same pattern.
The question is: How can the – once – accumulated magmatic pressure in the summit go off? There is more magma added with each episode than is erupted. So once in future there might follow a big event that releases the remaining magma somewhere. The summit becomes an increasingly loaded gun that can go off.
https://www.usgs.gov/volcanoes/yellowstone/science/summary-yellowstone-eruption-history
The USGS has quantified 4 different eruption sequences in the last 2.1 Million years at Yellowstone including rhyolitic lava flows since 70,000 years ago.
2450+280+1000+600=4330 cubic kilometers. That’s still only 0.002062 km3/year.
Granted however, Yellowstone probably has much greater magma underground than Pahala, but when it does come up it tends to do it all at once. Yellowstone or Iceland? Who has more underground?
There is probably quite a lot more, there is likely a lot of la a fill after 2.1 mya too, and the whole volcanism of the snake river plain is related and has been voluminous in the Holocene. Maybe the real volume is well over 5000 km3′ maybe even 6000, byt thats not a bif difference in 2 million years.
I think Yellowstone might be subject to most magma not erupting though, the actual magma flow has to be high to keep the rhyolite molten and the whole park so geothermal. The cyclic resurgence also hints of magma rising up then draining down, although that could be partly hydrothermal. Where it drains I dont know, maybe into the Snake River Plain through a deep rift type structure, basically the old roots of the dead calderas. Thats just speculation though I dont know if that is consistent with the geochemistry.
Regarding the Mars-base: I think the fundamental problem is that Mars is essentially a dead frozen planet, and thus lacks almost all the cycles that keep our planet alive and livable. So most of those cycles would need to be implemented explicitly by human technology, e.g., recycling of all the crap and junk. And there is no experience of doing that 100% tightly here on Earth (even Biosphere 2 failed, and the Antarctic research stations are not closed loops at all), because our life and even our so called hi-tech technological civilization piggy-backs a lot on Earth’s natural cycles. E.g., active tectonics -> exploitable ores! Where do you find for example copper on Mars?
Somehow I think that the people who do all those renderings of shiny, supposedly self-sustainable Martian colonies (and people who fall for them) have never visited a mine, a modern factory, a modern farm, or even a small-scale metal workshop (*), the latter with all the dust, burrs and other metallic detritus on its greasy floor.
(* Of course in the original sense of that word, before it became corrupted to stand for a tutorial meeting of academics and other nerds. Compare also how “park” nowadays often means any ugly industrial area.)
An Alien Super Earth ( rocky planet thats a bit larger than Earth ) maybe much better than Earth at driving plate tectonics and the life important sillicate – carbon cycle thats a planets thermostat. They carry more internal heat and radioactive fuel for doing so for much longer than our planet ever will. ..they are very intresting exoplanets
A 2008 study by the Harvard-Smithsonian Center for Astrophysics suggests Earth may in fact lie on the lower boundary of habitability: if it were any smaller, plate tectonics would be impossible. Conversely, “super-Earths”, terrestrial planets with higher masses than Earth, would have higher levels of plate tectonics and thus be firmly placed in the habitable range…
And any von Braun or Musk on that Super Earth would need to build truly gargantuan rockets, even if he were squirrel-sized himself!
Nuclear rockets, or railguns possibly. Although only the first option wouldnt kill you from the acceleration…
How many G’s a typical ant can stand? Maybe the first technological species on a Super Earth is a gigantic “ant” (or nearest equivalent) colony with a hivemind? Then it could emigrate to the orbit little by little, a few ants at time, that would maintain a telepathic connection to ground colony’s hivemind, in one way or another.
(Some of this gives me Olaf Stapledon flashbacks, “Last And First Men” specially).
I think ants cant even withstand 1 G if they are our size, not without major changes to their anatomy and skeleton. Theres a reason arthropods are mostly smaller than vertebrates. Its usually explained as oxygen, but its not that, coconut crabs are bigger than most carboniferous insects and can breath fine, and the biggest flying insect today is not a huge amount smaller than a Meganeura. Also that high O2 was present about 100 mya and there were no supersized bugs then too, but there actually still were well afyer the carboniferous when O2 was comparable or even lower than today… I dont know the real reason but it is probably because arthropods have to molt and are basically soft and helpless then, where an internal skeleton is grown with the organism.
I guess an animal, either on Earth in future or an alien, could look like an arthropod but possess an internal skeleton of some sort too. Armored vertebrates are pretty common and basically that (turtles, armadillos, ankylosaurs, etc) but those still have the ability to grow their skeleton with them.
But back to the original point, an exoskeleton wouldnt really help aliens be stronger alone. Something smaller than a mouse can survive falling at its own terminal velocity at 1 G 1 bar. But an animal with an exoskeleton and as big as us probably needs to be aquatic until adult stage and then stay a fixed size, and that puts an immediate limit on where it can live and a disadvantage if something else evolves a way to not need water. Which is basically exactly what happened 300 mya. Lots of insects are fully terrestrial now too but have hard size limits, and the biggest live in wet places.
Also, ants are devout and unwavering communists and aliens only ever land in the US for some reason so this wouldnt go well if aliens turn out to be like ants… 🙂
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTkaSBBOPleja3j4nOY4fIhzkISQg9cS_wt903y4LOT2KA-SQ00Q2MhCeU&s=10
O2 plotted over time. This seems to be a pretty widely variable number depending on source though. But it looks to have been very low when giant griffinflies still existed although they were not found much longer.
https://en.m.wikipedia.org/wiki/Meganeuropsis
290-285 mya. But still ‘only’ twice the wingspan or the biggest modern flying insects. So giant in a relative sense but would still be small compared to a lot of terrestrial animals.
Chemical rockets have a finite limit to how much an energy well they can overcome. At best its their energy density vs their mass but in reality its far lower than this. Apart from a few unreasonable chemicals and using ozone as an oxidant its the most reasonable high energy fuel is acetylene. It generates 12MJ/kg. Methane (+required oxygen) delivers about 10MJ/kg.
It takes ~30MJ/kg for low earth orbit and ~60MJ/kg for interplanetary (100Gm solar radius).
Using this handy calculator
https://space.geometrian.com/calcs/orbit-energy.php
And simply putting surface gravity to 20m/s^2
(yes albert, I know its more complex than that)
we get 126 mJ/kg for interplanetary orbit.
Round figures the rocket would need to be only 1/4 of its mass but the same engine output and duration. This is not possible with chemistry.
So typically life that is extraplanetary needs a small planet with a thin atmosphere (low cost to low long-life-orbit). These are a bit tricky, too small and you have no atmosphere, too big and you have too much.
Probably best to have a medium-sized planet (eh venus) and freakishly remove most of its atmosphere (by chemistry or collision) like earth.
Note that a stab;e (until it evaporates into interplanetary space) state of earth would be a thick water vapour atmosphere with astronomically high surface pressures and temperatures under the greenhouse blanket.
Life need not, and probably rarely does, produce a lifeform capable of leavinf its own planet, on theoretical grounds, let alone practical.
The way to get around and colonise space is by not starting from the ground. There are two problems. Most of the energy is used to lift things against the Earth’s gravity – once in space, it becomes much easier. And rockets are a relatively inefficient propulsion system because the exhaust velocity is much less than the escape velocity from Earth – they are not good enough.
So the idea is that everything possible is built in space, and only the people themselves are rocketed up. We have a convenient station nearby: the Moon. But it lacks some essential ingredients: water, carbon, etc. But these are plentiful in asteroids. So bring in an asteroid and put it in a low orbit around the Moon, and everything you need is there. From there, use ion drives rather than rockets as they have much higher exhaust speeds.
Think about it: a rocket works by throwing things out of the back window. How far would your car get of you tried to propel it like that? To call something rocket science is not a compliment.
The best way to launch into space would be a space elevator. But it would take two weeks for the journey to Earth orbit, so brings its own supply problems.
It would be better to put the asteroids in Earth orbit, I think. You could build the space stations on them too, or in them, and at variable distances between Earth and Moon.
I think the Raptor engines also have a thermal efficiency of over 60% to motion, which is probably the most efficient heat engine. So rockets are very efficient just chemical fuel doesnt hold much energy… Nuclear rockets have comparable specific impulse to ion drives in some cases, they might be better for some applications.
The issue with an asteroid in Earth orbit is the risk that it eventually collides with us.. Safer around the Moon. Also, the Delta-V needed to go to Mars is much lower from lunar orbit than it is from (closer) Earth obit.
The problem with rocket fuel is not the energy efficiency, but the exhaust speed. That is limited by the temperature of the burn which can’t easily be increased. It limits the speed to a few km/s. The rocket equation shows that, to go much faster than that, you need a LOT more fuel because you need to carry it all with you and accelerate it to a velocity where it becomes useful. Up to that point, it is dead weight and needs a lot of fuel itself to be accelerated. Ion drives are low energy but ten times faster speed. They work out much more effective.
Its not in low earth orbit, sit it out at a few thousand km with an ion thruster for minor adjustment and it should be fine, its going to be mined so never uninhabited and you could probably even just use argon as propellant, which is very cheap. Or out at geostationary, it cant hit us then, nor will it be drawn in. Last I read about it orbits around the Moon are unstable long term too. I also cant really see how an asteroid could be captured without it going into Earth orbit first anyway so the risk is still there.
I also wonder how bad an impact at orbital velocity would actually be. Obviously it would be bad as a direct hit, but it might still be much less energetic than a typical impact. I wonder if any evidence exists of this in the past, that Earth had a proper second ‘moon’ as a captured asteroid that eventually landed, making a crater but not hitting as hard. It temporarily captured a tiny asteroid for a few orbits last year.
A few thousand kilometre is low orbit. The Moon is 15 times further from the centre of the Earth! So interplanetary travel takes 15 times less energy from there. And it is within the Roche limit so the asteroid will fall apart. You need to be at least beyond geostationary orbit. You also need exchange of kinetic energy and angular momentum to park it into orbit. The Moon is ready-made for that.
Impact from orbit would be almost as bad as an object drifting in from the outside. It is a factor of 2 difference in energy.
Sorry, the meaning I intended was: “a huge colony of (small) ants”, not “a colony of (giant) ants”. So the question is: Does it help to be tiny, to better endure large g-forces?
More solid metal asteroids could probably survive within the roche limit, and those would be prime targets if we are going to bother. If it is built upon and strengthened as a structure too, or just completely transformed, it would also remove that factor.
Im also not sure that tidal disruption would happen so fast that it would destroy the asteroid before any of the above anyway. At least it looks rare for asteroids and comets to fragment completely from a close encounter.
Remember Shoemaker-Levy? Or the bodies that formed the rings of Saturn?
Look up what the Roche limit is. You don’t mess with it: for bodies larger than what can be kept together by cohesive strength (of order 1 km), it is irresistible. The Roche limit is a bit closer in for high density bodies. But not much.
Might I suggest 3753 Cruithne as that first asteroid base/mine? It regularly passes close to the Earth (but poses no collision risk). It’s probably been baked dry of volatiles, but so have most objects this side of Mars, and it may have valuable minerals, as well as being valuable as practice.
For the longer term though we’ll have to go farther afield: Phobos. It’s expected to have much more volatile content and unlike Mars’s surface it’s not nearly as deep into a gravity well. Phobos makes a lot of sense as a base and a refueling stop to serve as the next step on the way to:
The main belt, which has more accessible resources perhaps than Earth itself, and again without the pesky gravity well. Of course, once a breeding population of humans with a self-sufficient technology and manufacturing base exists there, they won’t need us any more and will likely leave us behind. But maybe they’ll remember where they came from and send us a care package once in a while.
Cruithne is an interesting one. It is on a horseshoe orbit which approaches earth but never collides. Disadvantage is that it can be on the opposite side of the Sun at times.
I was thinking of things under 1 km actually, and Jupiter and Saturn are not exactly comparable to Earth, or a comet to a metallic asteroid. From what I could find the Earth roche limit is 18,400 km away too so not at geostationary, and that only applies to something with 0 tensile strength, which is not the case of a metal asteroid, and definitely not the case of a structure we build from or on it, so it could be maybe as close as 15,000. Im not sure what the tensile strength of a completely natural metallic asteroid is, but it is probably higher than a rocky one and way more than a Bennu-type gravel one or a comet.
It would make sense to build a structure from the surface of the asteroid while mining it and that structure would be refined metal and much stronger, probably much too strong to be affected by tidal forces that way.
https://www.spacereference.org/asteroid/2016-ed85
Apparently this is the nearest M type asteroid with a known orbit and over 1 km size. There are doubtless millions of smaller ones but they are hard to see. But you would want it to be a sizable rock at least a few hundred meters to a km wide, and this one is going to be 15 million km away in 2098, so who knows maybe a mission to retrieve it could be set up then. By that I mean fly an ion drive to it, to move its orbit to a capture, which might be decades after…
Super Earths unless they are very very large does not have any killer gravity for humans on many Super Earths you are just somewhat heavier than you are on Earth and that maybe haves some health benefits maybe very much so if you manage to live on a small Super Earth. A somehwat larger Earth around a somewhat smaller sun coud be the ideal planet for life
A moderatly large Super Earth say 2 to 3 Earth masses yeilds only 20 and 30% more gravitation with an earthlike interior composition it woud still be possible with current tech spaceflight on a ”small Super Earth”
Mars is tectonicaly dead but large enough to do some very infrequent volcanism. Earth maybe indeed be a borderline case barely large enough to have active moving plate tectonics, larger Super Earths with hotter deeper mantles and thinner litospheres under more stress maybe ideal for plate tectonics
On Mars the low outside air pressure is awful only 1/100 th of Earths surface pressure. Everything in a Martian home needs to be air – tigtht a crack or broken window is disasterious INSTANT pressure decompression unless the leak hole is very small its a leathal enviroment souch low air pressure your facial fluids will boil due to lack of pressure keeping your water togther. There is just a few seconds of useful concious-ness if you finds yourself decompressed on the Mars or the Moon.. meaning a large rupture tear in a space – suit is a disaster. Mars habitats needs to be well sealed and the air locks seals mecanism must work everytime when you go outside and in. I guess that Mars – cities coud perhaps be better to be underground in large pressurized dug out caverns, there the residents does not need to interact that much with the extreme surface conditions and offers protection from small meteors and solar radiation.
You are much better well off in ways of air pressure in a zeppelin skytown on Venus that haves a very dense atmosphere: there you can be outside on balcony with only an oxygen mask it will be warm and pleasant 55 kilometers up and a leak in a wall in some lofty venusian cloud-city apartment is not an instant alarm CO2 sensors will be in every room I guess.
Venus blimp to me makes way less sense than Mars. The only advantage is gravity and air pressyre, but take that mask off and take a deep breath and you probably die even if you put it back on, 5% CO2 atmosphere is probably lethal very fast, and Venus at 1 bar is 20x that. And on top of that every reference I have ever seen has the temperature at 70-80 C at 1 bar so either that is wrong or I have no idea where the ‘earth-like’ conditions idea came from. Also just, we cant make a blimp city… And we still need a Starship type thing anyway, and cant use any resources on Venus.
On Mars, wearing a heavy suit to increase load on joints and regular exercise could counter the gravity issue. Beyond that, you are also on a solid surface with usable material and the atmosphere isnt as toxic, yes its also CO2 but much less than the toxic limit, and as a low pressure its not going to leak into anything anyway.
Accessible solid surface is a non-negociable for planetary exploration by humans really. We can physically survive a spacewalk on the Moon or Mars, but not Venus. And there is water and accessible oxygen on Mars too.
55 km altitude makes an earthlike outside Venusian temperature I think 30 c or so I remember thats similar to daytime in Hawaii lowlands its possible to sleep in that with some room some indoor air condition. The higher up you haves the steampunk skytown the higher oxygen % you needs in the indoor living room airmix to be able to breathe normaly. A an indoor inert mix with a very high oxygen % can be breathed at quite low indoor pressures its possible to have your zeppelin city in in high altitudes where its – 20 c outside .. but lower down is better with a more earthlike indoor mix allowed. I agree an underground colony on Mars is much better than a Zeppelin Town on Venus its easier to get back to Earth as well.
Because the indoors on its Venus will be pressurized/ isolated from outside atmosphere it maybe possible to float at very high cold altitudes on Venus thats saied higher up means more solar storm radiation and UV problems so its better to float lower down but avoid levels where its over 35 c outside
I mean, at that point you might as well build the blimp city on Earth…
I think 10% O2 in air is breathable, maybe would be 5% for birds. Fire cant start at 15%. An atmosphere of pure O2 at 15% pressure would be uncomfkrtable but you could breath. It would be better mixed with argon or nitrogen though. Also a vacuum is only 1 var pressure difference, and we havevast experience making things that can hold that. Technically going down 10 meters underwater and returning is as big a pressure change as exposing yourself to a vacuum. I cant remember where but spacesuits have had holes before, and so has the ISS.
Really the biggest issue by far is actually getting there, solving that makes the rest look easy. Going to the moon is a lot easier, not easy but its only 3 days, not a few months. Getting to Venus is probably harder than Mars too, at least using more fuel because you are falling towards the sun and have to counter that. It is faster and transfer windows happen much more often but still, rockets are at limits.
At lower air mix pressures the molecule density is lower so you needs a higher O2% to be able to breathe it. I read that some early space stations and spacecrafts where pressurized with a thin pressure of nearly pure oxygen, with pure O2 you can breathe a very thin pressure gas indeed to allow less structural stress on vessels and compartments like the lunar module that where a tin – can in strenght
Partial pressure, pure O2 but at 20% pressure is the same amount of oxygen as aur at sea level. 1 bar pure oxygen is a poison like chlorine or NO2, just not as quick… But 3 days in pure O2 at 1 bar would probably be dangerous ignoring the extreme fire hazard. Also that your own flesh is a fuel in that situation… O2 is not air.
Chad – Hyperbaric oxygen therapy can be at a pressure of 3 bar of pure oxygen for 2 hour sessions three times a day. It can go on for weeks and weeks.
Thats not continuous exposure though, 3 weeks would only be a total of 14 hours. There are also lots of cases of people getting oxygen poisoning doing it. If you sat in that chamber for 14 hours non stop there would be problems.
Pure oxygen at low pressure is, I believe, a much higher fire risk than with the nitrogen. This is why its not used, after an american (fatal) test went wrong. It should be easier to breath as it will have lower viscosity. As to blood transfer I think that’s probably just dependent on the oxygen differential with hemoglobin so probably not much affected (see Tibetans).
Chad – I checked, it’s up to 60 sessions of 2 hrs each. Three sessions per day.
So 120 hrs at 3 bar of pure oxygen. Six hours a day for three weeks. Pretty heavy!
I was wondering to myself what sort of O2 partial pressure whales would experience on deep dives. And N2 partial pressure. Whales seem to be immune to the bends though.
Living on Venus is like living on a CO2 gas giant in some sense: its a bottomless fiery pit below your floating city where no human can reach without being incenirated into atoms. True hydrogen gas giants will likley never be colonized due to high very entry/ escape speeds, high gravity and the air being too light to support any floating human structures..
Maybe you could use them as penal colonies for dangerous intellectuals. The gulags of space?
Im curious to know how an isolated one kilometer box of the Amazon jungles woud burn under 200 atmospheres (200 bars ) of pure oxygen just one match and it all goes up violently almost like a thermite reaction I woud guess..
At that pressure as soon as something lights the whole thing would probably detonate. LOX soaked into organic material is a shock sensitive high explosive and one of the most powerful, and 200 bar isnt quite so dense but it is closer to that than to standard air…
Im NOT going to Mars Im NOT going to an Elon Musk ”penal colony”. I understands the point of having two planets for backup in case cometary bombardment and other terrible future Earth disasters. But myself is not getting into that crammed flying tincan – phallus and going to his silly colonies thats ruled by that shady corporate man in souch a harsh dangerous enviroment that Mars is. Its really is an awful place to live in at least in the startup phase of Martian society where you basicaly haves dig in your own body waste to surivive lots of freeze dried turds 🙂 . https://m.youtube.com/watch?v=uqKGREZs6-w&fbclid=IwZXh0bgNhZW0CMTEAAR6OSmQqgr9ruBwcZgytViEjppTcejyJoWlvKa1Rbc3pINMJNHXO9P91lCR8vQ_aem_4hBj_J3zc-X-bjFYYA9UUA
Release the Xenomorph… a nice companion pet for Musks “mars slaves”
If a KT sized impactor with same composition hits Jupiter at steep angle woud it release more energy than the KT impact on Earth did? I knows that Jupiter simply does not have a solid surface but the entry speeds on Jupiter are so fast it is simply beyond what many persons can understand even, depending on angle you can get up to 72 km a second relative to Jupiter which is rather scary. And on a Brown Dwarf it gets even much more crazy…. 🙂
Earthquake party at Bardarbunga and Ljosfjöll: