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
https://www.youtube.com/watch?v=zloJ_yptWU0
Stunning beautyful really around 1 hour of otherwordly soundscapes: well of course it cannot be anything else than Iceland! it mirrors Icelands mysterious, dark otherwordly landscapes exactly. I dont know what my favorite section is of this track is but it does reminds me of a cloudy mysterious summer day at Thorsmörk or Laki lava fields, the lava moss emerlad green and dark cloud rags hangs over the table mountain and lonley black mountains rise up from the black plains into the fog layer, its very beautyful and all sound parts are just as stunning
Icelands mysterious volcano – glacial enchanted landscapes have fascinated me since a small child its almost goth during a rainy november day at Myradalssandur looking like some gothic horror, high fantasy or dark sci-fi film or something like that. Im free resident in Iceland as Scandinavian so I really dont want to miss this oppurtinities, its where I wants to be. A person that likes Icelands landscapes as much as I does is called an Icelandophiliac learning Icelandic will be a brutal grinder, hopes its possible even but its where I wants to be. A cloudy summer day or a cloudy winter day at Iceland brings the most otherwordly scenery
https://pics.craiyon.com/2023-10-14/cda8e58873f54aa8850f56be4f1bcfe0.webp
These are the best winter conditions in Iceland for many with camera. Its AI but gives some sense of an ideal winter day for me woud be near Katlas coast for and it is for many photographers these light conditions are the ultimate dream. For myself indeed it was exactly like this during my first visit in winter… season.. only the Aleutian islands are the only other place where souch stark volcano- glacial landscapes exists in any abundance …
Still strong uplift at Svartsengi, its not as fast as right after the last eruption but still a lot faster than for most of the year before that. At the current rate the inflation will break even with the last time in about a month. After how far the intrusion went last time I dont know where the next eruption will be, but up north of Sundhnjukur near the August vents or even further beyond might be more likely. This area has very few Holocene vents but that doesnt mean it is safe, trends can be broken. The August eruption was nearly at the northern limit of old vents but was far from small or short lived. Theres a reasonable chance of a north coast ocean entry next time too…
There are also still co stant quakes at Ljosufjoll. Not a real swarm exactly but theres always something there. Pretty good chance it erupts before 2030 I think, lets see 🙂
Kilauea is starting up once more.
South vent overflowed too, so this migbt be a big one. Hopefully more really huge fountains or even a new record breaker 🙂
We got a star just NW of Grimsvotn.
Drumplot looks a bit like one of the big ones. Expect some updates when this has been manually checked.
Looking at distant drumplots, this has to be the M5 we have been expecting from Bárðarbunga.
USGS calls it M5.3 but IMO has it at M4.8. Fairly deep at 9 km.
There was a M3.5 as well, that is more shallow at 2.6 km.
M 4.8 means 10^4.8 ≈ 63,096 energy units. What unit do they use as base for Magnitude?
Here they use a scale of Joules: https://en.wikipedia.org/wiki/Moment_magnitude_scale#Comparison_with_TNT_equivalents
Is the energy of M 0 = 1 Joules or different?
The formula for moment magnitude is Mw = 2/3*log10(M_0) – 10.7, where M_0 is the seismic moment, which includes both energy dissipated as heat and non-elastic deformations, as well as radiated energy. To get M_0 from the magnitude you need to rewrite the equation as:
M_0 = 10^(3/2*(Mw + 10.7))
The unit is in dyne*cm, which is 10^-7Nm (10^-7J).
Magnitude 0, Mw = 0, then corresponds to M_0 = 1.1e9 Nm. But wait a minute. This is on the same order as a magnitude 3 in the Wikipedia table, how come?
The reason is that the Wikipedia table lists the radiated seismic energy, which is on the order 5e-5 times the seismic moment. The relation between seismic moment and radiated seismic energy is not fixed, but depends on a number of factors, making it difficult to exactly compare magnitudes and energy values.
Somebody confirm for me if there was an earthquake seen on the HVO Live Summit Webcam at 15:48:22 HST? The BYL seismometer shows something right before 16:00.
?fileTS=1746495676
Not one large enough to be catalogued.
Io keeps erupting like CRAZY as always its the real volcanologists paradise! Juno spacecraft saw alot of crazy surface changes and been many thermal outbrusts. Near one of Io s poles there been a cluster of new mega lava lakes discovered a few of these are basaltic lava lakes that are bigger than Denmark..crazy
Our technology is capable of building a Mars habitat. The negative, dark side of our human psychology is a much bigger barrier. “Roanoke”.
Jesper, you’re right!
After the Andersson eruption we now have the Tomas shake. The predicted M5 (well -almost) occurred as predicted.
Is that a new dance move in the making.?
Only on special occasions 🕺
GPS of Bardarbunga show no movement. Should we expect it later or is the movement too small?
I would think that tge detector would have to be over the plug to detect any movement. Also the ice and conditions probably masks any movement there could be.
Askja looks also very calm now. Is the unrest over that we had some years ago? Sometimes Herdubreid had earthquakes, but the caldera of Askja has remained quiet recently.
For some of the previous quakes, we could see a step back in the horizontal trajectory of the KISA station (towards Bárdarbunga). If you look closely in the graphs, you can notice that there are no new GPS readings taken after the quake, so we still don’t know what effect the quake had on the GPS.
A new GPS data point has been recorded now. At KISA, the quake seems to have caused a 10mm step towards the east and possibly a small step towards the south. The N-S change is within the usual noise amplitude, so more samples are needed before we can know for sure.
Was the explosive eruption of Bardarbunga 1910 in the caldera or on Loki-Fögrufjöll (subsystem)? The informations are a bit confusing. The Catalogue of Icelandic Volcanoes says that 1910 was in the Central Volcano, but Wikipedia says Loki-Fögrufjöll.
There are no known eruptions from the caldera itself: all eruptions are assigned to the flanks or the fissure systems. But do be aware that Bardarbunga’s caldera was only discovered in 1973, so local reports could not have listed it as the location of an eruption. The 1910 eruption was under the icecap but not in the caldera region: it occurred near Hamarin, i.e. on the upper end of the fissure swarm. How near I do not know.
https://www.volcanocafe.org/icelands-eruptions-since-1900/
Thanks for the link! I read through all eruptions. Interesting is the “mystery eruption” 1913 of Lambafit. One of the many unexpected things Iceland can do.
The 1950s were quiet. This resembles a bit the period after Holohraun concerning the big volcanoes. 1948-1961 were 13 years without an eruption of them. Now we’ve had ten years.
The 1910 eruption happened obviously in a period, when scientific observation was impossible, and the event was too small to explore much afterwards. So it remains a bit uncertain, where the correct location was. Was the Loki-Fögrufell area the location of many explosive eruptions of Bardarbunga?
Wikipedia also links the most recent subglacial minor eruptions to Loki-Fögrufjöll. F.e. 2008 and 2011. But I don’t know how reliable this information is.
Is a subglacial eruption like these recent ones also likely to occur in the summit caldera, if the unrest continues? I imagine, if only a small quantity of magma comes up during the movement of the caldera, it may do a purely subglacial eruption that’s only visible in tremor monitoring.
Unless it breaks the icecap and is obvious, its kind of an unknown if every jokulhlaup is an eruption. Schroedinger’s eruption.
Well, definitely not every single one, probably not even a majority, but theres a lot of edge cases. Katla and Jamarinn in 2011, and I think Katla a few years ago. I think the Katla 2011 event got labled an eruption mostly because people were expecting it and jumped too early. It still could have been a tiny eruption but it hardly counts for altering the probably long overdue VEI more than 3 we are waiting for.
Loki-Fogrufjoll and Hamarinn are the same volcano too, I think. Or one is part of the other.
Kilauea is now overflowing from the north vent, no fountains at this time.
Pele will probably deliver some fountains again as HVO has scheduled.
HVO states “~30 gas piston cycles have occured in north vent since 10:48 a.m. Main lava fountaining phase is likely to start within 24 hours.”
Interesting that the pause between E19 and E20 has been very short until now. Is this a tendency or an outlier?
E19 was smaller, still same supply rate.
https://youtu.be/wHhfUnVnLg4?si=EblEBrKwE6r9GU5b
We all know about the deep quakes at Pahala and the new swarm at Ljosufjoll but there looks to be a similar situation in the Abu volcanic field.
Interesting.
Some more on Bárðarbunga:
Bárðarbunga quake actually 5.3 in size; gravity measurements underway (RÚV, 6 May)
Recovering 30% of the subsidence in 10 years suggests the magma chamber isn’t refilling that quickly, but a M5.3 is a M5.3, especially when it happens right under you while you are perched on top of a volcano. Yikes! It’ll be interesting to see the gravity data when they have it ready.
30% in 8 years, last measurements were done two years ago. Considering that roughly 2km³ were drained I’d guess that average refillrate was around 2.8m³/s so not too shabby
He is wrong about the recovery, Kilauea is at probably close to 90% recovered in 7 years, so much more. Even accounting Kilauea lost 1.5 km3 and Bardarbunga 2.5 km3, Kilauea is winning. Maybe he meant to say in Iceland only or translate got it wrong.
But 30% of 2.5 km3 is 750 million m3, meaning on average Bardarbunga has a supply rate of 0.075 km3 a year since Holuhraun ended. And that in 20 years time it will be fully ready for a repeat. Although I think it will be a rather longer gap of a few more decades and the eruption larger and to the southwest. In 2080 there will be about 5 km3 accumulated, and that should be enough for a Veidivotn eruption by itself. That isnt counting magma in Hamarinn that probably gets involved too, or Torfajokull and Hekla also inflating. So maybe a Veidivotn eruption within the next 50 years is actually pretty likely, although I doubt it will be before Bardarbunga recovers from Holuhraun so say some time between 2045 and 2075.
This is probably the highest supply rate of the major volcanoes of Vatnajokull at least counting magma that is entering the part that can actually erupt, Grimsvotn might have been more for a few years after 2011, but not long term. But it might actually be less than Hekla, and it is still getting its ass kicked by the Reykjanes volcanoes right now.
He might be talking about the plug being pushed back up. Usually, a caldera collapse is irreversible, and recovery is done by other means. Kilauea is restoring itself by pouring magma on the top instead of pushing the down dropped block back up.
I’m a bit confused about the many locations/subsystems of the central volcano: Bardarbunga caldera, Loki-Fögrufjöll, Hamarinn volcano, Gjàlp. Are there more subsystems of Bardarbunga in the Vatnajökull area that are outside the caldera? Where do the typical explosive eruptions occur usually?
87.5% of Bardarbunga’s eruptions are said to be explosive. But where do they occur most frequently?
The fountaining phase has started at Kilauea.
It’s already over. The last two episodes seem similar, with only the north vent erupting and being about the same size, though this one was more intense. It’s amazing how quickly we’ve changed from only the south vent vent fountaining to it being completely quiet.
And before the really tall fountains it was only the north vent again. They really do seem to be pretty independant, the south vent actually did erupt in the early activity too just not fountaining.
One thing I did notice, when the south vent does erupt, it tends to be taller and the episode is more voluminous, E16 was almost a full day of fountains above the rim. Episodes where only one vent erupts usually have short repose.
If you draw a curve from deformation depression to depression, you get a positive tendency since 8/9th April:
More shocking is that it even peaked over the caldera rim, despite having a lava pond (to be fair, the lava pond is shallower than before), so I wonder if the north vent becomes the one to break potentially records here. Maybe it’s trying to be a lava lake system – one pours, the other empty, yet it seems too gas rich and seperated to do that, but at times, some of the north vent lava drains into the south vent, like some earlier episodes.
It’s actually quite the opposite. I ran the numbers for effusion rate based on pixel-counting the µrads lost during each episode on UWD (with one µrad equal to 5 million m³ divided by 13 µrad (for ease of use this is 480 thousand m³), from HVO’s numbers on episode 18). As the HVO also states the duration for each episode, of which they’ve gotten better at as the eruption progressed, we’ve got the ideal ingredients to calculate the effusion rate during and the recharge rate ahead of each episode, which I did and put in a graph (note the recharge rates ahead of both episode 2 and 3 are skewed because significant drainback occurred during the pause; “recharged ahead” on episode 1 means the spike on UWD before it started):
Based on those numbers, episode 16 effused, on average, “only” 59.1 m³/s, and that with fountains well above the rim. However, episode 19, with significant action only from north, effused 99.1 m³/s on average and episode 20 under similar conditions did a staggering 140.1 m³/s, which is only surpassed by the onset of the entire eruption at 156.3 m³/s. Taller means not always more volume.
Looks like average effusion rate is increasing. That might actually argue against this passively evolving into a slowly erupting lava shield, seems like for that to happen the narrow conduit needs to rupture. As the cones get taller I have expected to see new satellite vents open but none yet.
It’s great to see some numbers on the eruption so far, thanks!
Interesting… so this eruption is only going to get more intense from here? If this trend holds true, then that might mean that future episodes might be shorter but more intense, therefore *maybe* taller lava fountains. I know that lava fountain height doesn’t correlate well with eruption rates, but looking at episode 20, the north vent’s lava fountain was taller than the caldera wall at certain points, despite of a lava pond that might damper the fountaining.
I am just going to throw this into the void, but if the north vent is dominant, it might throw fountains 1000 feet high, being very intense but short. If the south vent is dominant, it might get some record-breaking fountains going. This is only 3 to 5 days away, so we’ll wait and see.
If this eruption was to reach that coveted lava fountain record, it’ll look like a pyroclastic column pretty much, like this of Kīlauea Iki’s 1900 foot fountain…
Realized an error in remembering the (rounded) volume of 1 µrad: should be 380 thousand, not 480 thousand as in my message earlier. It doesn’t affect the numbers on the graph, as in the script I wrote “urad = 5000000 / 13” – if my computer calculates that incorrectly, I seriously wonder how it managed to survive 5½ years without noticeable mathematical errors :).
About the lack of satellite vents, I don’t think we’ve seen them because both vents function as each other’s satellite. If one doesn’t work, it can pick another one without consequences. During the two episodes of insignificant north vent action, magma thus already had a second, well-established, vent to make use of (south), thus no reason to try its luck elsewhere.
Though maybe the biggest factor in the lack of satellite vents is that magma doesn’t have to travel that far to the exit – if I may say so, straight up and out. With the MERZ eruptions, magma had to travel from the chamber quite a distance out to the exit. Enough chances, despite an established pathway, to encounter an obstacle or a new path out, especially when there’s a non-constant flow rate as during Pu’u’o’o’s fountaining phase, or so I think.
At this time I think the cessation of fountaining will be marked by north’s inability to transition from gas-pistoning to fountaining – as it can already hang in there for extended periods of time, demonstrated several times now -coupled by south’s inability to begin fountaining. The latter because in several episodes, south was “pushed” higher with each north vent cycle, eventually initiating fountaining.
I think there’s technically a satellite vent, one usually perched above the south vent to the south. It’s usually only active once the south vent does high fountain episodes.
I found that a rough number of 0.5 million m3/microrad works, or close to it. The problem is that this eruption despite being repetitive isnt necessarily super consistent. Lots of times SDH and UWE dont respond equally between episodes, and only UWE can really benefit from a volume applied to its scale, SDH is affected by two or more magma systems from different directions and they both move in the eruption, so SDH cant just be divided by m3/microrad.
It is also very subtle, but the GPS data might suggest slight inflation, or at least caldera extension. Its still well below levels around Christmas but is slowly climbing.
For flank vents I was thinking something like the vents in the 1820s or 1919, leaking out some lava from the caldera without being truely deep sourced vents. Kamakaia Hills, and the recent eruptions in 1974 and 2018, were true SWRZ eruptions by contrast. I also think there is a reasonable chance a vent could open in the east side of the 2018 caldera, based on a persistent set of quakes over there.
I also have the impression that the gas emissions have increased in the pauses:
HVO observed “sulfur dioxide (SO2) emission rate of approximately 1,750 tonnes per day (t/d) was measured on May 2” https://www.usgs.gov/volcanoes/kilauea/volcano-updates
We can interpret increasing sulfur gas emissions as an indicator for increasing overall magma recharge.
Increased SO2 emissions can be both higher supply rate and also a wider or more efficient open vent. When the lava lale was open before 2018 it was going at multiple times higher than it is now, and at a rate higher than it was able to refill, so the whole summit was degassing hence why the 2018 lava fountains were pretty low compared to 1960. I think most or all of that degassing has been reversed since then though, the new lava is very frothy.
HVO said in one of their update messages that the eruption rate was about 200 m3/s in the first half hour of the episode.
V2cam still shows a bit spattering:
Not sure if this has been posted before.
https://www.soest.hawaii.edu/soestwp/announce/news/kilauea-ash-largest-phytoplankton-bloom/
“Kīlauea volcano’s ash prompted largest open ocean phytoplankton bloom
Posted on April 8, 2025 by Marcie Grabowski”
“When the Kīlauea Volcano erupted in May 2018, an enormous amount of ash was released into the atmosphere in a plume nearly five miles high. A new study by an international team of researchers revealed that a rare and large summertime phytoplankton bloom in the North Pacific Subtropical Gyre in the summer of 2018 was prompted by ash from Kīlauea falling on the ocean surface approximately 1,200 miles west of the volcano. The research was published recently in JGR Oceans.
“The scale and duration of this bloom were both massive, and probably the largest ever reported for the North Pacific,” said David Karl, study co-author, Victor and Peggy Brandstrom Pavel Professor, and director of the Center for Microbial Oceanography: Research and Education in the School of Ocean and Earth Science and Technology. “Our study shows the connection between the eruption of Kīlauea and bloom formation far from the volcano. This can be used to refine our understanding of phytoplankton bloom dynamics and to improve our understanding of the ocean’s carbon cycle.””
Great fertilizer for the words clearest bluest, most nutrient devoid ocean… a temporary feast in the desert of the sea
Hekla 55 years ago (May to July 1970): https://www.youtube.com/watch?v=N7WP20BxynY
1948-1970 was a break of 22 years, shorter than the present break of 25 years. 1970 Hekla erupted 0.2 km³ lava. 2000 Heklas did nearly the same effusive volume in two weeks, what 1970 happened in two months.
2000 was closer to 0.1 km3 of lava, but nearly all of it erupted on the first day, I think the only activity after that was spattering at one of the vents. 0.1 km3/day is almost 1200 m3/s average rate, it must have been much higher at the peak.
I think Hekla has possibly gone back to its old ways though. So next eruption might bot be for several decades but will be big when it does. The timeframe in question also lines up roughly to when Bardarbunga might next send a dike southwest, so perhaps a combined eruption could happen. Not a directly triggered eruption, but both going in short succession or even the same time
Wikipedia says 2000 was 0.189 km³. Larger was 1947-48 with 0.8 km³, it looks like a Hekla version of Holohraun. It was the second largest lava eruption of Hekla since Vikings.
Wikipedia is a bit outdated on that, 1970 and 1991 eruptions were about 0.2 km3, 1980-81 and 2000 were 0.1 km3. Very rough.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL076887
2000 was the smallest in volume of the 5 recent eruptions unless you count 1981 separate. But it was just as intense to start off.
Thank-you for the link Chad!
1947-1948 they estimate 0.742 ± 0.138 km³. Is it one of the largest basaltic andesitic lava eruptions on Earth of the 2nd millenium? Usually big volumes of lava are caused by basalt. Anak Krakatau also does magma around basaltic andesite, but less volume.
I’m not sure how many basaltic andesite eruptions have actually happened. Lots of magma with that composition is dacite with mafic crystals and not actual melt. One is basically a viscous liquid filled with solid crystals and the other is a free flowing liquid.
Theres a pretty good chance Heklas eruptions are the biggest example of an intermediate composition magma erupting as a free flowing liquid. It is viscous compared to the majority of Icelandic lava but still erupts in the same way, the notorious explosive opening is just a vent clearing stage, the large majority of Heklas eruptions are effusive. I suspect that was also the case before 1104, the ages of many lavas there are very poorly known even though many are probably historical.
Some BH s ackreation disks compared to distances in our solar system the power of even these ”microquasar”ackreation disks are tremedously grandiose stuff compared to anything we are familar with in our solar system or anything we are familiar with in our daily lives… and then of course there is megaquasars thats another level of insanity …
Please give a link also to that Astronomy article where that image is from.
Snaefellsness is collecting stars like there is no tomorrow. This is I think the 5th one this year? Almost (but not quite) an M4
But the activity is all very deep still (12-14 km is the shallowest I’ve seen). If it keeps going like this it may take years or decades before we seen any surface action at Snaefellsness.
Volcano watching is not for the impatient…
Decades of boredom and hours of terror ..
That’s what I’ve always said about stormchasing. Drive twelve hours straight, for fifteen minutes of video.
Years possibly but I doubt it will be decades, the way it has accelerated from basically nothing to what it is now seems too fast for that. Before 2030 for sure, but my guess is next year.
From RÚV:
One of the largest quakes recorded at Grjótárvatn (RÚV, 8 May)
Not much info, but IMO is keeping an eye on the swarm, as you would expect.
A failed Soviet Venus mission is going to cause an artificial meteorite (=Space Debris) accident: https://www.bbc.com/news/articles/cy9vz28nyedo
“it could potentially land anywhere from as far north as London to as far south as the southern tip of South America”
This was covered on Watchers eleven days ago:
https://watchers.news/2025/04/28/kosmos-482-spacecraft-reentry-may-2025/
The Youtube-video included in that has interesting original footage:
https://www.youtube.com/watch?v=6fuS5Mz2d2U
(and the automatic translation from Russian to English seems to work quite well).
Also this video about Mars-3 probe has nice green patina on it: https://www.youtube.com/watch?v=7osihYX3bQg
The thing about Kosmos-482 is that because the capsule was intended to survive landing to Venus through its thick atmosphere, it will probably survive intact down to Earth as well.
There is a chance it would survive. The deceleration regime is very different though and it also depends on whether it will start to tumble.
It is possible the parachute has come out in orbit. That would make the initial descent hard to predict although the parachute would not survive long.
Status 10 May 09:56 CEST
As the descent craft was not spotted by radar over Germany at the expected 07:32 UTC / 09:32 CEST pass, it is most likely that the reentry has already occurred.
From:
https://blogs.esa.int/rocketscience/2025/05/07/reentry-prediction-soviet-era-venera-venus-lander-cosmos-482-descent-craft/
The most likely location of the re-entry is over the southern ocean
I recall a story about a Venus probe accidentally landing on Earth and causing havoc. It is mentioned in ‘The Martian’ (a highly recommended book for nerds) as a most unlikely event as it is not normal for probes to land on the wrong planet. He was wrong: it is now happening exactly as in that story.
Found it: https://bionic.fandom.com/wiki/Death_Probe
You are warned
$6,000,000 wouldn’t by much these day, maybe a bionic pinky!
I guess nowadays you’d need to buy subscriptions to access the various features of the bionics. And AI would be added, so the body would do all kinds of unexpected things just because the AI thought that would be a good idea.
There’s a new geologic map of Mauna Loa:
https://pubs.usgs.gov/publication/sim2932E
The Kanimoe flow forming most of the coastline looks like another potential flood lava eruption and probably a caldera collapse, which also shows these dont necessarily always happen from the rift zones.
From the publication.
“p5e3, a5e3, Kanimoe flow—
Picritic flow originating from summit of Mauna Loa traverses northwestern Naohueleelua, Puu Anahulu, Puu Hinai, and Anaehoomalu quadrangles. At one time, this unit formed the coastline from Weliweli Point to Puakō. ʻAnaehoʻomalu Bay formed as result of this eruption. Characterized by clear, large, subhedral to anhedral olivine as large as 10 mm that form 15–35% of flow. Both pāhoehoe and ʻaʻā occur. Pāhoehoe flow tops locally have lower abundances of olivine; flow interiors contain as much as 40% olivine. Plagioclase abundances range from 0 to 4% as phenocrysts. Groundmass dull gray. FID 159”
Yep, this was definitely a major eruption, probably multiple km3 of lava and erupted very fast. So it seems that Mauna Loa actually can do radial vent caldera forming eruptions too.
After reading through further, it looks like picritic a’a summit eruptions arent actually unusual, not typical but this massive flow really was erupted without a big drainout event. Without much else to go on at that age its hard to say but its possible Mauna Loa had a mature ring fault caldera back then and could do fast eruptions without draining. But still to get lava flowing that far and with so much volume all the way to the ocean…
The overlying Kaniku flow was probably a summit collapse event though, being a large pyroclastic cone with evidence of tall fountaining.
Also that there was a radial vent eruption in the 1730s, apparently. Radial Vent 414, very small but also very far from the summit and both rift zones. At this point it is one of only two dated flows younger than the Hapaimanu eruption and older than 1843, the other being the Manuka flows near Ocean View erupted in the 1810s. Its weird that a radial vent could open here at this time though, even at its oldest it is still in the 1690s, and equally could be as young as 1770. The youngest Hapaimanu could be is also 1770 but as old as 1650, so it is very likely older. Theres also nothing about the vent that suggests it is an eccentric eruption unrelated to the caldera, no tall cones or weird chemistry. Maybe Mokuaweoweo had lava in it that drained and refilled for a few decades, before Kilauea took over in the 1740s, and this vent was the only drain that actually erupted.
“Also that there was a radial vent eruption in the 1730s”.
When the radiocarbon age is calibrated it actually puts the radial eruption in around 1660. It was part of a series of NERZ-radial eruptions that likely started with a low rift eruption, a middle rift long-lived voluminous one, and a final radial one, likely being the same sequence as in the 1850s. Hapaimamu likely happened right after this sequence. The NERZ sequence has a lot of radiocarbon dates for the flows, the calibration curve is very steep for those decades, and as far as my memory goes, they all fall around 1660 so it was very likely around that decade when it took place. I seem to remember another NERZ eruption took place shortly before or after Hapaimamu.
The age of the summit overflows is the part of the new geologic map that interests me most, though I will need some time to look at it calmly. It was likely a very particular extreme of Hawaii activity with Kilauea completely quiet and Mauna Loa fully dominant, but the rifts largely dead, which allowed Mauna Loa to erupt an isotopic chemistry close to the “Hawaii mean”
As I understand it radiocarbon is done starting at 1950, which gives a range of 1690 to 1770, with a mean at 1730? The late 1600s age is consistent in all the other flows in these maps, but this one vent is younger. I guess it is possible to be older than Hapaimanu but the mean age HVO gives suggests otherwise.
Well, radiocarbon is complicated. The ages given by the USGS are in conventional radiocarbon (yr. BP means conventional, while cal. yr is the real age), which is the common thing they do. But the half life of C14 was later found to be a bit longer than in the conventional ages, and the isotopic carbon composition of the atmosphere that plants entrain has also changed over time, so the conventional age needs to be transformed into to the real age with a “calibration curve” that takes into account these factors. I do so with OxCal.
But if the dates are all calibrated with the same method the ages should still be relative to each other?
Even ignoring that, its strange that a vent could open so faw from the summit and not be a major event. Yet there are other very similar flows a couple centuries older nearby too, unrelated in cause but maybe there is something about this particular area.
Theres also a flow that looks like it flooded out in a couple hours from a fissure parallel to the contours, with lots of big blocks rafted out a short distance. Must have been a lava lake drain, its fortunate the eruption in 1877 wasnt on land above Kealekekua Bay or it could have been much the same but bigger.
I think you are probably right about the Kanimoe flow being a caldera event.
Thanks Hector! I’ve tried to find out the age of the lavas on the saddle between Mauna Loa and Kilauea.
There is the Ke‘āmuku Kīpukakēkake flow close to Kilauea Caldera. It belongs to “Age Group 1 (pre-A.D. 1843–1,000 yr B.P.; Holocene)” Does this mean that the eruption in this area happened during last thousand years? They also describe its age as ” 288±36 radiocarbon yr B.P. FID 800″. This applies to a time around 1700.
Yes, the flows in the saddle of Kilauea and Mauna Loa were erupted on the NERZ in the second half of the 1600s. Radiocarbon starts from 1950 to avoid nuclear testing related errors, at least I think it is around 1950. So basically whatever the average age given is, add 75 more years.
Ke‘āmuku Kīpukakēkake flow was erupted in about 1662, although it could have been as late as 1698 or as early as 1626. Among eruptions on the northern and eastern side of Mauna Loa only the Ke‘āmuku flow on the north flank is probably younger, average age of 1672. So it is very probably the youngest prehistoric NERZ eruption, meaning there was a gap of 181 years before another eruption there.
Other than these two, the only eruptions known for sure are Hapaimanu in about 1710, Radial Vent 414 in about 1730, and Manuka in about 1809. Wikipedia mentions possible eruptions of Mauna Loa in 1730, 1750 1780 and 1803, the first and last of these are probably the RV 414 and Manuka eruptions, the 1780 eruption was probably the Kaupulehu eruption of Hualalai. The 1750 eruption was maybe Kilauea, which was very active at that time, or an eruption within Mokuaweoweo. The 1832 eruption was only seen on Maui somehow and seems to be controversial.
When I have time I will map these eruptions. At least of the vents. The NERZ was pretty active in the 1600s,
1880-81 was the most recent lava flow towards the Kilauea saddle, but didn’t reach far enough. During last 200 years we’ve had three lava flows towards the Mauna Kea saddle, one towards Kilauea and one to Hualalai (and surrounding its northern part).
The Kilauea saddle only gets lava flows from Mauna Loa, if an eruption happens on NERZ and has a favourable position. Most NERZ eruptions happen to the north of the ridge, so they prefer to run northeast.
It’s interesting that the 1859 Hualalai encircling lava flow is not unique. The geological map shows, that eruptions like this occur repeatedly. Mauna Loa has a preference to do radial vents in the NW area so that lava flows can run NW:
There’s also a minority of pre-1800 lava flows which ran over Southern Kona. This area is safe from SWRZ eruptions, but some radial vents also sent lava flows in this area south of Hualalai. Events like this are rare, but possible.
The image link didn’t work, so I use the PDF link with the big map: https://pubs.usgs.gov/sim/2932/e/sim2932e_sheet1.pdf
Kilauea saddle might be about to flood with Kilauea lava in the next few decades the way things are going now, while Mauna Loa seems to be the same as it was after 1984 so unlikely to erupt again for a while. 2022 was a smaller volume than 1984, 150 million m3 rather than 220 million, so 1984 was 32% bigger. If the magma supply is similar then maybe the next eruption will be with a 32% smaller interval. Which is 26 years, the next eruption might be in about 2048. Of course, at its current rate Kilauea will erupt almost 6 km3 of lava by that point, even if it erupts only half that it will probably fill the caldera, and certainly spill south at least.
Its an interesting pattern that the majority if lava flowed south from the rift in the 1600s eruptions, while most historical lava went north. There was some speculation the next eruption would flow south but that didnt happen either. I wonder if Kilauea probably having a deeper caldera back then is a relevant factor, it was always pretty full historically from the 1830s onwatds, draining a few times but filling quickly. There are phreatomagmatic deposits from the 17th century I think, and probably a caldera collapse in that century too, so it seems Kilauea probably had a caldera much deeper than it was in the 19th century. Kilaueas summit cant be pushed and opposes the NERZ from spreading at a deep level properly, so it being drained could allow that flank to move more freely and encourage eruptions southwards.
Regarding dates, the 10 most recent dated prehistoric eruptions seem to be these. All using radiocarbon provided and scaled starting from 1950. Only 7 flank eruptions occurred between 1600 and 1843, apparently. HVO hasnt released a map of most of the SWRZ and western flank yet though, so there are likely more. But still, here are the dates.
RAD = radial vent.
1809 SWRZ – Pele Iki/Manuka flow
1730 RAD – radial vent 414 flow
1710 SWRZ – Hapaimanu flow –
1672 RAD – Ke’amuku flow
1662 NERZ – Ke‘amoku Kipukakekake flow
1650 NERZ – Pu’u Kupanaha flow
1639 NERZ – Kipukamauna’iu flow
1574 NERZ – Landing Zone/Pohakuʻohanalei flow
1548 SWRZ – Kipahoehoe flow
1540 NERZ – Ainahou flow
Obviously eruptions in Mokuaweoweo arent visible.
Yes, it’s possible that Kilauea is building up towards a shield summit eruption now. Something like this would allow unusual and uncommon directions of lava flow, f.e. over the southern flank between SWRZ and ERZ. We can try to imagine where lava would flow, if the current vents rise above the caldera rim.
If a longterm shield eruption like this needs a lot of magma, this might be a reason why Mauna Loa has lost some access to magma supply and Kilauea gets most. Kilauea does a shield eruption like this probably more often than Mauna Loa. Last 1000-1500, now again. Mauna Loa had its last shield eruption until around 1270 AD and has probably to wait for another 1000 years to get it again.
Kilauea already js doing a shield summit eruption, question is more about if it will overflow the summit or if a similar vent will open on one of the rift zones instead. At the moment it is looking increasingly more likely that this summit eruption really will overflow the caldera though, the vents are at about 1000m elevation which is more than high enough to set off rift eruptions, but both rifts are dead silent and only weak deflation from south flank movement is evident at Pu’u O’o.
Im not sure about if Kilauea really does shield building summit eruptions more than Mauna Loa though. If we only count the times the calderas were actually overflowed then Kilauea last did so between about 1000 and 500 years ago, but before that was at least 2500 years ago. Mauna Loa has a lot of summit lava and radial vents with fewer rift eruptions between about 1100 and 1900 years ago, indicating no long lived caldera and probably most of that time a lava lake that often overflowed. Although probably no one there to see any of it 🙁
It is worth noting that in that interval 1000-2000 years ago there was the gigantic SWRZ eruption of Pu’u o Keokeo lava shield above Ocean View about 1800 years ago, maybe a 50 year long eruption. It seems to have been both a tube fed pahoehoe eruption and a lava fountain eruption with variable and sometimes high sustained eruption rates that didnt just smoothly transition from one to the other. The eruption also ended in a lava flood eruption at neighboring Pu’u Ohohia and likely a summit collapse, the total volume of this eruption possibly being Laki sized though mostly a lot slower. There is a summit overflow that is dated to about 1700 years ago, so whatever collapse did happen was filled in in about 100 years. About 1500 years ago was when the Pana’ewa basalt under Hilo airport was erupted too, which was a huge lava flood like 2018, but there are summit overflows dated to only 10 years after, so whatever caldera it made was gone within a decade. Which is possibly very similar to Kilauea today and could support a very active future to come…
The actual end of these summit overflow eruptions seems to have been about 1300 years ago. There are some major radial vents to about 1100 years ago though which probably needed a summit lava lake still. Starting from 1300 years ago large SWRZ eruptions started happening, as well as a flow towards Hilo 1400 years ago, but kilauea had a shield building eruption making Kanenuiohamo about 1000 years ago and maybe also summit overflows starting before this . Mauna Loa dudnt have an eruption of the type to create a caldera until about 800 years ago (Kipuka Kanohina at Ocean View), and Mokuaweoweo probably didnt reach its current dimensions until about 1700 (Hapaimanu) or even 1868.
I want to add though that TECHNICALLY the 1949 eruption was a summit overflow of Mokuaweoweo. 🙂
The map also shows lava flows from the summit. They cover 64% of the NW slopes of Mauna Loa. We haven’t had any historically. They must be different to radial vents or rift zone eruptions. How can we imagine lava flows from the summit to spread NW or elsewhere?
With the present slow speed of filling the caldera, it will take centuries, before a summit eruption can spill over the caldera rim. Are there times when Mauna Loa hurries to fill the caldera faster?
They say that Mauna Loa was in a very active state between 50 BC (Julius Caesar) and 1270 AD (Louis IX of France) with a core of 750 years with most activity.
“vast sheets of pāhoehoe originated from the summit of the volcano … Sustained activity sent flows repeatedly to the north and west … Flows from this period blanketed the north and west flanks and reached the sea near Puʻuohau (west) and from Kīholo to Puakō to the northwest.”
Was it after this highly active period that the Mokuʻāweoweo Caldera was formed?
Mokuaweoweo formed in probably about 1710 with a massive SWRZ eruption at Hapaimanu, under Ocean View. It maybe grew a bit in 1868 too. Maybe a caldera of some sort existed before.
Summit overflows are the same as Kilauea doing
They say about Mauna Loa’s 1st millenium summit eruption:
” Summit flows represent long-term steady state activity,
similar to what was observed during the Puʻuʻōʻō eruption
(A.D. 1983–2018), with a fixed vent region, sustained magma
supply, and moderate-to-low effusion rates. The region is
dominated by pāhoehoe lavas with lesser amounts of ʻaʻā.”
Shield eruptions like this are rare on Hawaii’s volcanoes. Kilauea did it 1000 to 1470. They allow the summit to do lava flows until the ocean and to cover areas that now are usually lava proof. When they begin, they can last for centuries.
They also say that the summit overflows caused Kilaueas caldera to collapse, still, even after watching how it really happened 7 years ago… the style of eruption lasted centuries but just the fact there are numerous radial vents and even major drainout eruptions the same age as the summit overflows shows it wasnt really just overflowing for a few hundred years with nothing else. Kilauea the same way probably had eruptions on its SWRZ during the summit overflows. And at least one major eruption on the lower ERZ at Pu’u Kaliu that is about the same age as the younger summit overflows, and Kaliu is literally a road gravel quarry so testing its age should be easy… Radiocarbon is good but doesnt give detail in the short span we observe. Radiocarbon wouldnt be able to tell us that the 2018 eruption and Pu’u O’o happened 3 days apart, or that the summit fully collapsed and refilled in a single decade. We know it because you can see it, literally live right now.
Even as I posted that list, all those eruptions had margins if error of decades. The 4 eruptions in the 1600s all had enough error to be in almost any order, really. It would be pretty hard to find the progression order of a lot of the 1840-1950 eruptions too, actually often only the biggest vent is obvious and even that isnt true, until the new map released I thought the 2022 cone formed next to the vent of 1899, but it actually formed next to the main vent of 1855…
Random, but I was browsing Google Earth & Open Topography today when bored, and I came across an area that was really fascinating to look at using Open Topography. It’s fascinating to find items in there that are visibility more interesting or noteworthy than when you look at things in Google Earth satellite view.
I can’t say I know of anywhere else in the world where there is a volcanic feature quite like this. Points if you can guess what this is / where this is.
Newberry volcanic system?
Nope, it’s the Chichinautzin volcanic field in Mexico.
I know that one well, one of my favourites. The chemistry is also very unique; this system and the stratovolcanoes to the right has some of the highest SiO2 for a given MgO content of the world, a bit like the antithesis of alkaline magmas in a number of major oxides like SiO2, FeO, or CaO (though not all). And the other such locations on the world with this extreme endmember have smaller scale volcanism, I think.
Yeah quite fascinating. I figured you would guess it given your familiarity with the region. The total volume is rather tremendous – 470 cubic KM emitted in around 40,000 years supposedly.
I think I once looked at that area when I was looking at volcanoes near some massive cities, and I noticed all these small cones on the outskirts of the city! Some of them are even surrounded completely by buildings, so they could be quite destructive.
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500 km3 in 40,000 years is 0.012 km3 a year, which is pretty high, over 1 km3 a century. Maybe that is all going to Popocatepetl but I dont know if that makes any sense for geochemistry either. And Popo isnt erupting that much either probably. It would explain high gas emissions if it is the vent for a huge deep complex though.
Eruption every 1400 years at Chichinautzin in the Holocene from GVP data, although in real life its not so predictable. Last was 1700 years ago but only 100 years after its predecessor which was after 2000 years but that 3rd oldest has a 1500 year margin of error… Still seems like a pretty high risk to happen this century. Not as bad as a major earthquake but an eruption in outer Mexico City would be a problem even if it us just a tourist eruption.
I wonder if most of the volume of the rist us uplift too, as the intervals should be giving 10+ km3 eruptions every time which isnt the case as far as I know. Maybe the area is a far future supervolcano.
Blah Blah Chiles-Cerro Negro Blah Blah another swarm Blah Blah…
I am so sick and tired of this stupid volcano, I don’t want to talk about this volcano anymore but it keeps doing crap to get my attention. If it wasn’t for my health, I’d have already published an article about the current situation.
On the border between Bavaria and Czech Republic they found a maar that’s only 288 thousand years old: https://gfzpublic.gfz-potsdam.de/pubman/faces/ViewItemOverviewPage.jsp?itemId=item_2653917
Cold War prevented studies there until 1990. So they’re bit late in examining the area compared to the Eifel studies.
The topic of maars let me think about Iceland’s maar eruptions 1000-2000 AD. There were at least three maar eruptions: 1. Ljótipollur 1477 (part of Veidivotn eruption, https://guidetoiceland.is/travel-iceland/drive/ljotipollur), 2. Krafla’s Viti 1724 and 3. Askja’s Viti 1875. Were these all maar eruptions during this time?
Hey, I think there’s soattering at the North vent at Kīlauea at 4:09 or 4:10 PM Hawaii time…
It’s possible that the eruption develops towards a higher “ebb” level between the episodes. There is a shallow magma body somewhere below the cones. If it rises slowly over the episodes, it can do low-scale activity (effusive Strombolian spattering) between the episodes.
Maybe, if we had a vertical view on the cones, we could observe an actual lava lake comparable to the 2008-2018 lava lake that sometimes was very deep in Halema’uma’u. Then the lava lake gave cameras a better perspective.
Added to this a contraction of the pauses between the episodes can be possible. If this happens, the overall output of lava could increase. Ten episodes in a month erupt in sum more than four. Number of episodes per month 2025:
January 4
February 4
March 5
April 2
I’ve also noted that the inflation has flattened on all three summit tiltmeters. Is the eruption moving towards a balanced mode?
The Venus lander crashed over the Indian Ocean, west of Indonesia. 50 years late and on the wrong planet, and of course it was not designed for a water landing. Otherwise, no problem
Apparently it’s still quite uncertain where it actually fell:
https://www-tiedetuubi-fi.translate.goog/kosmos-482-on-pudonnut-saattaa-kellua-meressa?_x_tr_sl=fi&_x_tr_tl=en&_x_tr_hl=fi&_x_tr_pto=wapp
Herðubreið had a 3.1 quake with serveral aftershocks … or was it a magmatic earthquake swarm? Depth around 4-5 km.
We had a 4.1 quake south of Knoxville Tennessee this morning at around 25k deep. Felt over several states, including Atlanta and north. No shaking at our house.
Looks like someone popped up for a bit of sunbathing. Must have left his horns at home though…
Durr… image link failure.
Thanks Albert.
Oh my!
Nice
Might not last much longer, E21 should start within a few hours.
https://www.smithsonianmag.com/smart-news/scientists-stumbled-upon-an-active-volcanic-eruption-in-a-mid-ocean-ridge-for-the-first-time-ever-180986586/
Happened only 2 weeks ago, on the Cocos ridge far off Costa Rica
First time a mid ocean ridge eruption has ever been observed happening on location. There is actually direct video of the lava erupting in the distance too, not just recently solidified. Eruptions like this must happen very often somewhere along the whole ridge system, if the ridge system generates 21 km3 of magma a year then each 1 km stretch of the ridge would make about 300,000 m3 of magma a year. But with no big difficulty in rising maybe a lot doesnt get stuck rising up, and so ypu could get small eruptions every few years everywhere. It would take 3000 years for a 1 km3 section to generate 1 km3 of magma but thats still means there are at least 20 magmatic events involving 1 km3 of magma in a single year, in theory…
V1 Kilauea cam shows occasional small flames interspersed by small explosions. Can’t be real fire, me thinks, but might be very hot sulphate particles? Just guessing.
HVO writes “Yellowish flames in volcanic vents are due to burning of hydrogen gas”.
Not sure what their statement is based on as sampling or flame spectroscopy would both be tricky to perform…
In a previous daily update, they linked to this Volcano Watch article from March 2000: https://www.usgs.gov/news/volcano-watch-flames-vents-are-hydrogen-gas-burning.
Thanks, that is interesting.
It happened in 2022 too, shortpy before I saw it there was fire observed at that years vent.
I have assumed it is because of water reacting with Fe2+ in the rock, oxidising it and leaving either H2 or further reactions with either SO2 or CO2 making H2S or light hydrocarbons. Probably all of these really, although the latter two seem to be more after the eruption has stopped. There also might be other redox reactions occurring too with other metals but theres a lot of iron in Hawaii basalt so it seems likely that is the main reason.
Chad – H2S, SO2, H2O and elemental sulfur are in an equilibrium
2H2S + SO2 = 3S + 2H2O
I used to know the temperature when the equilibrium produced equal concentrations of each, I think it’s around 450 C. Gets complicated when you start to look at the allotropes of sulfur, since it polymerizes (the yellow stuff is S8).
What all this means is you will tend to have H2S, gaseous sulfur and SO2 all in the same gas stream. Relative concentrations would vary depending on how much of each of the four species are present.
I should get around to put the thermodynamics package I have onto my new laptop. It produces excellent temperature/concentration tables and Porbaix diagrams. It was on my old one but the disk died.
To holger and JO. Pure hydrogen flame is almost invisible. The colours will come from heated dust or other incandescent impurities. It should be rather easy to do spectroscopy on the coloured flames to determine the elements/compounds producing the colours, only requiring a telescope and a diffraction grating. Would make an easy project as part of a masters or high school project (access permitting).
Suggest it to HVO.. Yes, I had been wondering why it was seen at all. It is moving very fast so whatever is causing the yellow glow is mixed with the gas, and is not tephra. So you think aerosols. The heat is coming from the chemical reaction (mind you – there is quite a lot of heat there already) but the light is from the something that is heated. The fact that hydrogen appears just before the episode take off shows that the episodes are driven by new gas. Hydrogen is very light so arrives first.
My guess is H2 but with a coloured flame from sodium emission. Sodium tends to dominate over other emissions spectra even in low concentrations. Hawaiian basalt has 2-3% Na2O, which isnt much, but the other metals of higher concentration are polymerized oxides so probably cant really be involved.
It is anything that is dust-sized. Some will either glow incandescent in the flame (~black body) or will vaporise enough for ions to form in the heat. Just sprinkling salt on a bunsen will give you yellow, potassium blue strontium red etc, (chemistry 101) so particle size isn’t exactly that critical. I am not quite sure if some dissociation is a requirement, but if so, many compounds (even NaCl) must dissociate sufficiently to produce ions in a hot flame. Actually its quite easy, I remember throwing copper carbonate into a campfire to produce impressive blue-green flames. Caused “some surprise”.
Thats what I mean, sodium ions in the flame giving it colour like if you sprinkle salt in a bunsen burner.
I wonder actually if highly potassic magmas with very low Na would have a violet flame, that might prove this hypothesis.
Does a significant Hydrogen content allow the interpetation about the magma source?
Picking up now
Really going now.
Lots of lava flowing out but low fountains. Probably going to be over in a couple hpurs again and resume later in the week. I noticed pressure might be higher on tbe tilt than last time, so possibly at some point soon the south vent will erupt again too and we get bigger episodes wider apart. South vent still glows at night and is degassing, it isnt dead but just doesnt get involved now, its a lot like a few months back.
As I say this the fountains are going taller… not enormous but over 100 meters for sure.
Definitely taller!
Must be 250 meters or so.
Yes it really shot up, maybe the south vent is closing up now, or at least all the pressure is at the north vent. Although both vents have lasted long enough to be fully open so this is probably just temporary. Maybe they will merge with a collapse if magma intrudes southwest.
Interesting the tiltmeters dont show any deflation yet. Usually they respond immediately, but not this time. There was a daily variation on UWD that was spiking up when the eruption started which could have covered the start signal but that seems a stretch really. If it isnt just delay on their site (mist likely) maybe there was a big pulse of magma that might have given this a boost.
Did lava already touch down on the caldera rim? I expect that the next episodes are going to to this. It would be the first lava outside the caldera since 1982.
Now we’ve got a truely massive fountain.
Ok now the tiltmeters show deflation, at this rate it will be over in about 4 hours or less, so another short episode. But if fountains get way higher and stay that way or the south vent opens then things could be interesting.
Amazing action right now!
S2Cam
Live cam but even after all that lava rain the south vent is still a drain, its still open just not erupting. Fascinating how they are so close but must be separated from deep down.
Only hours after E21 and both vents are glowing bright and 1 microradian of reinflation has already happened. Again the south vent is just as bright even though it only weakly erupted near the end of E21.
The minimum level of deformation is higher than in March/April. Deformation doesn’t fall below the level, at which previously the “inflation eruption” started. We’ve got a persistent eruption in which the episodes are moments of peak eruption.
I also have the suspicion that there is or are on resp. two lava lakes inside the cones. There is now webcam that have a good perspective to show them. But the illuminated steam&gas cloud indicate that there must be something like a lava pond.
This fountaining looks way more violent this time around.
The amount of lava gushing from the north vent is incredible, unlike the narrow tall jet of the south one, the north one makes a colossal fan, and even if not as tall it’s clearly gaining height each time.
This video shows a great view of the initial lava fountains:
https://www.youtube.com/watch?v=CjxwJhtie-U
Does the height of the lava fountain show, how tall the vent can grow in future?
Fountain of episode 21 is lower now, but the lava flows seemed to be more intense than they were during the fountaining, like a flood gushing out rather than a fire hydrant. Maybe it’ll reverse and go full fountain again…
Fountain fallout means lots of lava spread out, when it is lower it all falls in the crater and flows out the spillway so the full volume goes in one spot. Also tends to favor lava staying as pahoehoe for longer and flowing further.
Who says the North vent can’t do full on fountains! What caused the pressure to change from the South vent to the North in 5 episodes?
Probably the same thing that caused the south vent to take over in March, the two conduits must be separated to a great depth and perhaps one or the other will just be easier. These episodes are intense but so far not as voluminous as a month ago, April 1st was huge. So maybe that means pressure isnt relieved as efficiently by a single vent.
The curious thing is how the south vent still glows at night like there is lava in it, and the eruption now hasnt been able to fill it in, so the vent is open…
Maybe it was not the north vent that had a problem, but the south vent that was having a boost in fountain height. Like farmeroz noted, there may have been a partition of gassy and degassed members, but I’m not sure why, where the south vent was erupting the gas-rich part and the north vent the gas-poor part of the same magma conduit. Causing the south one to produce taller fountains relative to eruption rate than is usual for Hawaiian eruptions. Looking at old videos of Mauna Ulu, I think the thick, bright fountain we have seen in the last episode is the normal thing for Hawaiian volcanoes.
Interesting is the significant increase of episode frequency in May. In April there began only two episodes. In May we’ve already had three episodes from 1st to 11th May. The tiltmeter shows the higher frequency. If it was light, it was a “blueshift”:
The epevation of the vents is growing pretty rapidly. Compared to the rest of the crater floor. By tge time the lava is able to overflow north over the rim into the main caldera both vents will probably be higher up than the caldera rim behind them, and might even be overflowing that way already.
I remember when the ledge behind the north vent was flooded by lava in late January and it looked huge, but now the vent itself is nearly that tall and fountains past the rim are expected… 🙂
The last map was 87.5 million m3 after E18, there are now 3 episodes after. E19 and E20 were both about 4-5 million m3, and E21 now looks to be similar or stronger. So its likely today the total volume erupted will be over 0.1 km3. In only 6 months…
They don’t publish the elevation of the lava field anymore. The last summit map doesn’t allow well to follow the growing lava field/shield.
However, the video shows that the lava fountain grew much above the caldera rim. I’d estimate ~100m above the caldera rim and up to 400m above the lava field. https://www.youtube.com/watch?v=CjxwJhtie-U
It’s possible that the height of the lava fountains are growing and will grow with the height of the cones. I imagine that there is some pipe effect that allows the lava fountains to grow even more in future. It looks probable that lava fountains will put lava drops outside the caldera. Until now there was only tephra accumulating outside the caldera. But future lava fountains may add lava.
Yes at some point this year I think fountain fallout will land on the rim directly and form spatter fed flows.
Pu’u O’o didn’t do the highest fountains in the first year, but later. Maybe this is a model of how also this eruption is going to rise towards the sky. Imagine a 400-500m high lava fountain. Until then the base of the lava fountain is going to rise, because the cone growths like a classical shield volcano.
Pu‘u‘ō‘ō was a shield eruption. This doesn’t have to apply exactly as a model on the summit, but some aspects of the development are possible there too. Pu‘u‘ō‘ō did 4.4 km³. The current rate of the eruption is higher. We’re probably in the period that resembles Pu‘u‘ō‘ō 1983-1986. Afterwards the eruption will probably shift towards a steady lava tube & channel eruption.
How much volume is the eruption going to do 2025? Are roughly 0.3km³ appropriate? With this rate the eruption would do in 15 years the volume of Pu‘u‘ō‘ō.
Pu’u’ō’ō could be a model, but with a few significant differences. In the first 3½ years of its period, it has produced about 0.559 km³ of lava (or less than 0.16 km³/year), it had longer pauses (65.3 days compared to 12) yet emitted larger volumes per episode. Again, Pu’u’ō’ō is on the rift, whereas here it’s at the summit so they are different. They are similar in a few ways so this is the best we got for this eruption for now.
However, it is true that the tallest fountains could come later in this eruption, based on this. For all I know, it could be around 95 million m³ (0.095 km³) at the moment in the first nearly six months of eruptive activity, hence has the capability to possibly far exceed that of Pu’u’ō’ō.
Since the last time I posted the episode graph, I’ve refined the calculation method (previously I used pixel count of a section for the whole graph to calculate µrads gained and lost, now I use the pixel count of the whole graph to get a more accurate number). In any case it results in slightly higher numbers, however not drastically different than previously.
Based on this, episode 19 effused 2.9 million m³ (corrobates with HVO’s “just under 3 million m³”) at 101.8m³/s, episode 20 2.4 million m³ (corrobates with their “approximately 2.5 million m³”) at 147.2 m³/s (HVO approximately 140 m³/s) and the latest episode, 21, effused 3 million m³ (no HVO figure yet) at 106.6 m³/s. Certainly close to 0.1 km³, but still needs one or two episodes to surpass it.
How much is the volume of the Kilauea Caldera (Kaluapele)? If we assume ~2km³ to fill it up completely, we would get this with the present speed within 7 years. And we can’t exclude that the rate still can increase.
A difficulty for filling up the caldera is that the lava doesn’t grow with horizontal layers, but as a sloped shield volcano. The peak is in the yellow western part of the caldera. The foot of the shield volcano is at the moment on the east end of the down-dropped block. This foot is probably going to rise and flood the caldera. Later it’s uncertain whether lava fill the caldera or leave the caldera towards the SWRZ:
It will overflow the 2018 caldera completely in about June 2028 at current rates. Because of how the vents are elevated, lava already might spill southwards by this point even without filling in the whole caldera pit. It might take much longer, decades or more, for Volcano House to be in danger, because the lava is going to flow south in preference when possible. But overflows will begin before 2030 barring a catastrophic drainout again.
There’s even the option that lava from the present source will flood Kilauea Iki Crater.
In near future it looks possible that lava ponds develops in the two vents. HVO writes about them: “magma remains shallow in both the north and south conduits”. It’s now a “magma lake” some meters below the surface. Puʻuʻōʻō began 1986 to develop a lava lake. I expect that we should await something like this sooner or later.
Another flurry of earthquakes at Ljosufjoll
After a visit to Venus, we travel to Turkey. Istanbul has a past, but does it have a future?
https://www.volcanocafe.org/istanbul-and-the-marmara-sea/
Have you all seen this? I had to watch it a few times to believe what my eyes were telling me (watch the land outside of the gate carefully):
https://youtu.be/77ubC4bcgRM?si=lwcmQ65lCABOpb1Q
It lines up with edge of the green. Could it be infill above a pipe which is splitting?
Shawn Willsey the geologist covers this video in some detail. Worth a watch for his explanations.
https://www.youtube.com/watch?v=CfKFK4-HNmk
It’s certainly an incredible video. As Willsey said, possibly the only film of an actual rupture occurring on the surface.
Ongoing swarm east of Grimsey, with several quakes over m3.
It is fairly common in this region. Thew swarm may lasts for some days. It is a creeping fault which is prone to this behaviour. Note that the largest earthquake occurred at the start of the swarm, and the swarm followed immediately. Volcanic dikes tend to start slower, or have a time lag after a larger event before the die forms. So I expect this is tectonic.
I usually dismiss them as tectonic in this area, it was just a larger swarm than I’m used to seeing, but then I also don’t remember seeing a 4.9 before there either.