Snow is beautiful. It turns the world white and unblemished. Children love it for play, grown-ups love it for what it hides. Soon the snow will melt again, or worse, it will age like the world ages, lose its colour and become pockmarked with dirt. The beauty is temporary, here today, gone tomorrow. What was hidden will be revealed again – a memory come back to life, for better or worse.
Glaciers lack the beauty of snow. They carry the scars of age, the collected debris of the years. The surface can be so dirty that it looks like rubble, and needs a fall of snow to beautify. You need to dig down to find the ice. There may also be black layers embedded in the ice, evidence of nearby volcanic eruptions. Vatnajokul is full of those, caused by the frequent eruptions of Grimsvotn. But like the snow, the glacier hides what lies below. At the bottom is the rock, made barren by the scouring of the ice. Once the ice melts (as it will, one day), the scraped rock surfaces. It can take a long time before new soil builds up. We can still see the aftermath of the ice age in the scoured, soil-less lands of northern Canada, the west coast of Sweden, and many other places.
The rock which lies hidden below the ice contains the memory of a landscape that predates the glacier. There are events here from long ago. And not all that it covers is expected. This is the story of one such event, hidden below the ice of Greenland.
Inglefield Land
The Nares Strait separates the northwest coast of Greenland from Ellesmere Island. According to political ownership, Europe and Canada are only 30 km apart here. Geology, of course, puts both sides of the divide on the American plate. The straight line of the Nares Strait is typical for a fault line, an old one as there are no earthquakes here now. Indeed, this once was a strike-slip fault with some 70 km offset. The width suggests that there may also have been some extension. The fault was active around the opening of the Labrador Sea to the south, 60 million years ago. The precise date is not known, though.
Along the Nares Strait are some ice-free areas of land. The largest of these is Inglefield Land. It is 10 degrees north of the arctic circle, and the climate is not kind. There are only three months each year where the average temperature is above freezing, and in winter -20C is normal. The US has an airbase nearby, at Thule. It was the cold war at its coldest. Still, in sheltered places there is grass and other tundra vegetation.
There are people for whom this is home. High in the arctic, the area has a small population of Inughuit, polar Inuit who have been here for centuries. About 800 live in the region around Thule.
http://tiinaitkonen.com/works/inughuit-1995-2002/
Archeologists have uncovered some of their ancient dwellings. The people here lived in houses for the nine months of winter, mainly in the area around Marshal Bay. (There is not enough snow for igloos.) The houses were partly dug into the ground, with an entrance tunnel, a stone-paved floor, walls made from cobbles and a roof build from stone and sod. In the summer the people would remove the roof to let the house dry out, and move away to do summerly things (hunting along the coast and in the eastern part of Inglefield Land), before returning in autumn to reassemble the dwelling. The dwellings that were investigated all had the roof removed: the people had left in spring as normal, clearly expecting to return in autumn but this time had not done so. Whether they had not returned or had build a new house nearby is not known. Archaeology cannot answer all questions: it only finds what was left, not what was taken.
Source: Darwent et al. 2007, Arctic Anthropology
In the 1860’s a few Inuit migrated north from Baffin Island and mixed with the local population. They re-introduced some forgotten technologies, such as bow-and-arrow, and kayaks. Westerners too came and they developed the Thule trading station, which later became the airbase.
The Inughuit were thus not the last to live here. Neither were they the first. The Inughuit had arrived in the area around 1300 AD (the people of that era are known as the Thule.) Before them came the Dorset people, seal and walrus hunters who lived here from 2000 BC to around 1100 AD. The longest Late Dorset longhouse known in Greenland was discovered in the Inglefield area, dating from before 1000 AD. Genetic studies have shown that the Inughuit are not their descendants. As an interesting aside, the Dorset people used iron blades on their harpoons, with the iron taken from the Cape York iron meteorite, found on the ice a little to the south. Stone tools were used to hack off iron fragments from the large meteorite. By about 1300 AD, the local Thule obtained some trade good from the Vikings to the south, perhaps traded during the summer walrus hunt. Different worlds mingled here.
Inglefield Mobile Belt
Sentinel image, August 2021
Inglefield Land lies north of Thule. It is an ice-free coastal region, a 20-km wide arctic desert with little precipitation – no more than 150 mm per year. In-land lies the Greenland ice sheet which spills over the mountains into large glaciers. The Hiawatha glacier which lies above Inglefield Land does not reach the coast (unlike the Humboldt glacier to its north), leaving Inglefield Land habitable for non-vegetarians. The area has been ice free since 6000 BC, when the ice barrier in the Nares Strait collapsed and warmer water from the south entered the Strait. After 1500 AD the ice began to advance again as the Little Ice Age took hold, and areas in Greenland further north than Inglefield became abandoned. Nowadays, as almost everywhere on Earth, the ice is retreating again, but the Hiawatha glacier remains larger than it was 2000 years ago.
The sparse vegetation grows on ancient rock. The bedrock at Inglefield Land is just under 2 billion years ago. It is an interesting region for its geology. In geology too, this was a place where worlds collided. We now recognize an east-west structure extending from here across Ellesmere Island. It is called the Inglefield Mobile Belt. The belt lines up with the edge of the old craton of Northern Canada, all the way to Alaska. Is this all part of the same structure, the old fault where North America and Siberia once came together and separated again? We have written about this in the White Christmas post: the time when the world almost ended. Later, the oldest parts of Alaska migrated 2000 km along this fault, to the west where it rotated into its present location (see the Wrangellia post). We don’t know for certain whether this is all the same structure. Sometimes alignments are real, and sometimes they are just coincidences.
Magnetic map showing the east-west linear belt. Source: Nutman et al 2011. https://ro.uow.edu.au/scipapers/910/
The rocks here are far older than the Franklin event of White Christmas. The rock to the north has an age of 2.5 billion years. There was a later event which intruded magma and granite, dated to 1.9 billion years ago. This was apparently a plate collision which tilted layers vertically. A volcanic island arc may have been involved, coming in from the south. Behind it followed a continental block that is around 2.8 billion years old which now forms the area around Baffin Bay. The two blocks came together in the Inglefield Mobile Belt, with the old volcanic arc contributing to the southern part. The southern craton is now called the Rae craton. The Inglefield Mobile Belt is a young suture, in comparison, a 1.9-billion-year interloper still keeping the two oldies apart.
Geological map of Inglefield Land Source https://www.mdpi.com/2072-4292/11/20/2430
After the parts had come together, Inglefield had a fairly uneventful life. During the Cambrian it sank below sea level, and sediment covered the old rock. At some time a short fault formed in the northern part, running southwest to northeast. It runs parallel to the Nanes Straits and may have formed at the same time, an ‘also-ran’ fault that eventually failed. It is recognized because hydrothermal activity left a gold/copper mix on the surface.
Hiawatha glacier
The Hiawatha glacier lies east of the northern section of Inglefield Land, close to this gold-copper belt, and rises above it. It forms a semi-circular shape, attached to the Greenland ice sheet further in-land; a thin lobe of ice extends from Hiawatha to the northwest, flowing through an opening in the rock wall into a valley. The photo below shows the snow-covered ancient bed rock, with the thin lobe of ice and in the background the arc of the large glacier rising above it all. In the summer, pools of melt water develop on the far side of the Hiawatha glacier.
NASA image, taken from wikimedia
The Hiawatha glacier never attracted much attention. Ice is not scarce in Greenland, and the area was of no particular importance. Science looked elsewhere.
Impact
The first direct evidence that the glacier was well worth a closer look came during a visit in July 2016. A few hundred meters beyond the end point of the Hiawatha glacier lies a sandy flood plain, where a river deposits sediment from below the glacier. This floodplain had started to form after 2010, in response to the rapid local warming. During the one-day visit, sand was collected from the floodplain for analysis. The team found crystals of shocked quartz among the sand. Such crystals form in highly energetic events. A large impact seemed the most likely explanation, and the implication was that somewhere under the Hiawatha glacier there was an impact crater. It was time to remove the ice.
Crystals found in the search. ‘A’ shows the linear shock features. They run at several angles: this is sometimes seen in the central uplift of large impact craters. ‘G’ is an ellipsoidal grain with seems to have shrunk a bit: this is typical for a melt droplet, ejected by an explosion.
Of course, removing the ice is not trivial (though it is not beyond our technology – pumping CO2 into the atmosphere will eventually do the trick). To look below the ice, there are two faster options. One way is to drill through it. That requires luck, as the drilling only samples one location and that may miss the expected crater. The other is to use radar. Perhaps surprising, a radar signal at a frequency of tens of MHz (wavelengths of 10-20 meters) can penetrate ice. Not perfectly: imperfections in the ice will scatter some of the radar signal. Especially layers of volcanic ash can be problematic. This makes the method perhaps less suitable for Iceland, where glaciers are full of these layers, but Greenland has had no volcanic activity for the last tens of millions of years. The little Icelandic or Alaskan ash is too little to interfere with the radar. Internal boundaries in the ice also reflect the radar signal. This may for instance be at a boundary between stationary and flowing ice. A shear zone with broken ice will give lots of reflections.
The strongest boundary is at the bottom of the ice sheet, where the ice lies on what remains of the bedrock, after 3 million years of scraping. If enough of the radar signal makes it through to the bottom, a nice reflection signal tells you the depth of the ice. Tests have shown that such a radar can see through 3 kilometers of ice. Put the radar on an airplane and fly it across the entire ice sheet, and the radar will produce a map of the real, deeply buried surface of Greenland. The job is perfect for NASA which owns several research planes, used for various purposes. The mapping has been done over the past decades. The instrumentation has improved over that time. It now uses an ultra-wide band system developed in Kansas; it transmits 6 kW of power using 8 antennas, covers a frequency range of 150-600 MHz, and emits pulses that repeat at a frequency of 10 kHz. The transmitter is on the body of the plane; two of the three receivers are mounted on the wings. (The third receiver is the transmitter.) The aircraft flies 350 meters above the ice. The radar can measure the depth with an accuracy of better than 20 m.
Here is an example of such a radar profile, taken somewhere in Greenland. It shows the different layers where the ice has internal reflections, the chaos of a shear zone, and very clearly the grounding layer. The empty regions in the left part are cause by strong reflections higher up, leaving too little signal to get through. On the right there is another empty region; it is caused by a steep cliff on the bottom which reflects the radar signal away from the receiving aircraft.
The search for the shocked crystals had of course not been done on a hunch. It was still a closely guarded secret, but the radar mapping done over decades had shown signs of something extraordinary. A few months earlier, a more detailed radar survey of the Hiawatha glacier had confirmed the signs. The team had chartered the helicopter for a day to confirm what they already suspected. There were only 18 hours to find the confirmation, but that was enough.
There was indeed a meteor crater underneath the Hiawatha glacier, and it was not a small one. Neither was it a typical large, 10-km crater. It wasn’t large: it was huge. It turned out, the Hiawatha glacier was the crater. The semicircular shape of the glacier was caused by the crater rim. The glacier had grown inside a huge impact crater, filled it to the brim and grown up further. The glacier extended only about 1 kilometer outside of the crater – that single kilometer had hidden the secret. This was among the 25 largest impact craters known on Earth, measuring a tremendous 31 kilometers across. And no one knew.
The crater rim turned out to be 320 meter high, with a further 600 meter of ice thickness above this at the highest point of the Hiawatha glacier.
The bottom of the crater was rather flat, with a 50-meter tall rise in the central 8 kilometer. This shape is typical for such a large crater. Small craters (such as Meteor Crater in the US) have a bowl shape, with the deepest point at the centre. This what you get from an explosion in solid rock. Volcanic craters, if not filled with lava, have the same shape. But explosions in soft rock create a flat surface inside the crater. This is seen for instance in maars, where the explosion happens in wet rock. The explosion originally makes the same bowl shape, but the soft rock flows back and reshapes the bowl into a plate. Big impacts do this because they have so much energy that they partially melt the rock below. A very large impact can even cut through the crust, and expose the ductile layers below.
Gosse impact crater, Australia. This crater is 5 km across and has some similarity to Hiawatha, although much smaller. It is too small to show a central peak.
Why the central rise? It is known from large craters on the moon: they often have a central peak. It comes from rebound. The explosion pushes down the rock below, and after the explosion the rock rebounds and overshoots, finally freezing into position as a central mountain. (In an even larger impact, the rebounded mountain collapses again before it freezes, and in a second rebound forms a ring around the centre.) In Hiawatha, the central peak has been largely removed by erosion from the ice, and remains as a low plateau.
The crater rim is breached in two places. One is on the southeastern side, where two channels have merged. The second is on the northwest, is much smaller and is the source of the small lobe of ice flowing into the valley. Apart from this, the structure is remarkably well preserved. This may be because the bedrock in Greenland is so hard and so resistant to erosion (all erodable material has long gone). It might also be because the structure is young.
The impact happened within the Inglefield Mobile Belt. We know that the belt extends to Hiawatha: the sediment carried by the river from the northwestern glacier has the same composition as the material from the belt. The crater is symmetric and shows no deformation that would have happened during the formation of the belt. Therefore, it formed after the Mobile Belt had become immobile. This however is not a severe constraint. Very little deformation has happened here since. Even the opening of the Nares Strait might not have affected the area of the crater.
However, the crater is not as deep as it must have been originally: when it formed, it would have been 800 meters deep. That suggests that the rim and central peak have been significantly eroded. Erosion rates for Greenland are not well known: it could have taken anywhere from 50,000 to 50 million years.
Dating the crater is hard enough. Can we date the ice? Ideally, that would be done by extracting an ice core and counting the annual layers. The desert-like climate ensures that the annual layers are thin. At 10 cm precipitation per year, a kilometer of ice can build up in 10,000 years. In reality the layers will be much thinner than the annual precipitation rate, because of evaporation and compression. Thus, the ice could be as old as the ice age.
About 100 meters above the bed rock, the radar mapping shows a layer which reflects a lot of the radar signal. This has been seen elsewhere in Greenland. Where it reaches the surface, it has been shown to date to the Younger Dryas, the sudden cold and dry period when the ice age briefly came back, 13,000 years ago. The layer contains a lot of debris. If the layer inside Hiawatha is the same it means that the ice here is at least as old as the start of the holocene. Below this layer, the structure of the ice is complex. Ice from the late glacial period, (more than 20,000 years ago) which is present in the Greenland ice sheet, is not seen or is strongly deformed inside Hiawatha.
Surprisingly, the radar reflections show evidence for ground water underneath the glacier. This may be the source of the sediment in the river. Could the ground water come from the residual heat of the impact? That heat could linger for up to 100,000 years. However, this is speculative.
Based on the evidence from the crater and the ice, the original discoverers argued for a date within the past few million years (the pleistocene). This implies a highish erosion rate to bring the rim down by 500 meters.
The Younger Dryas
Could the crater be much younger than this? The crater lacks ice from the ice age. This has led to the suggestion that the crater did not exist during the ice age: it formed in the warmer period between the end of the ice age and the onset of the Younger Dryas. This was an extraordinary claim. Impacts of this size (requiring an impactor of 1.5-2 km across) may occur on Earth perhaps once every few million years. To have one only barely 10,000 years old would be a major event.
There had been other, earlier suggestions that a major impact had happened somewhere on Earth around this time. The original claim came from spherules and melt-glass found on sites in Pennsylvania and several other places. The sites had been dated to the start of the Younger Dryas. These locations also show enhanced iridium and platinum, as might come from a major impact. It quickly developed into a catastrophe theory, with the impact being the cause of the extinction of the large mammals in North America, the disappearance of the Clovis culture, and even the Younger Dryas itself. Enhanced iridium and platinum was also reported from a few sites in the southern hemisphere. Evidence for widespread forest burning in North America added to the evidence for the disruption. But a culprit had not been found: there was no impact crater of the right age and size.
The theory ran into trouble when later analysis showed that several of the original sites did not date to the Younger Dryas. A statistical analysis of the carbon dates from the sites confirmed that the various sites did not trace the same time. To get around the lack of a crater, the suggestion had been made that instead of a single event, it had been a meteor swarm with airbursts across the globe. To explain the variety of dates, a cometary swarm was proposed with impacts over a period of time. When a theory needs such complexities to explain missing evidence, it begins to look rather weak. What it needed was an actual crater. Could Hiawatha be that crater? It was in the right location for North America, and such an age would neatly explain the missing late glacial ice inside Hiawatha.
A clue was found in the crystals collected from Inglefield Land. Unshocked fragments showed compositions consistent with the local bedrock, not unexpectedly. But the shocked crystals and melt fragments show additions to this: they were enhanced in elements such as copper, chromium and gold, and with high rhodium. No local rocks show this and it likely came from the original impactor. Most impactors are made of silicate rocks, but about 10% are metallic, with high iron content. The impactor that made the Hiawatha impact crater appeared to have been such a rare metallic object. Platinum is often associated with iron meteorites, and the spike in platinum abundances at the start of the Younger Dryas had already led to the suggestion of an iron impactor. However, the fragments analyzed from Inglefield Land showed low platinum content, so the evidence did not quite come together.
There were some problems with the idea of such a young age for the Hiawatha crater. The impact would have ejected some 20 km3 of rock, forming a debris layer 200 meters thick around the crater, and 20 meters thick 30 kilometers away. The debris should have shown up in the Greenland ice cores, but nothing has been seen. Could the debris all have been carried away by the ice? Or was the impact under a shallow angle, directing the ejecta away from Greenland?
An association of the Hiawatha impact crater with the start of the Younger Dryas has run into too many problems: the low probability of an impact this size this recent, the lack of evidence in the ice cores and the evidence for 500 meters of erosion of the crater walls point at a much larger age. It may be possible to circumvent the problem by having the impactor hit the ice sheet. Models show that for a 2-km deep ice sheet, a much shallower crater wall and central peak is formed, because the ice absorbs the impact. There is also much less rock ejected from the site. However, this is double the current ice thickness (already amplified by the presence of the crater) and that would put us deep within the glacial maximum, long before the Younger Dryas. A search was made for impact grains in marine deposits associated with the Younger Dryas, but none were found. An association with the Younger Dryas seemed unlikely.
Age
We learned more about the impact from the crystals. The structures of the crystals indicated that the crater cooled rapidly after the impact. Soon after the impact the crater seems to have filled with water. This is consistent with an impact in ice, but it could also be a water-rich, warmer era.
Many of the crystals that were analyzed contain organic material. In one study, organics were seen in 5 out of 6 grains. Carbon dating failed to give an age: this indicates that the organics is older (perhaps much older) than 40,000 years. The material has been identified as coming from burned pine trees. But pine trees have not grown here since the early pleistocene, 2.4 million years ago. Could the crater be this old, predating the ice age altogether, and having formed in a much warmer period? Could it even be the eocene, a warmer period before the world began to cool towards the ice ages?
The controversy around the age was finally resolved this year. Carbon dating is suitable for young dates but not old ones: C-14 decays too fast, leaving nothing after some 40,000 years. But there are other radio isotopes that decay much slower, and these can be used even for geological time scales. Argon is itself not radioactive. When a rock solidifies it has no argon: as a noble gas it escapes the melt. But potassium remains in the rock, and the isotope potassium-40 (40-K) decays (very slowly) into an isotope of argon. Because now it is solid rock, this argon cannot escape. By measuring the amount of argon and the amount of potassium-40, the ratio can be give the age of the sample. The half time is more than a billion years, so that the method works for very old rocks (but not for very young ones!). The second method uses uranium, which over very long times decays into lead. Again, by measuring what fraction of uranium has decayed, the age of the rock can be determined. Because of these methods, we can measure surprisingly accurate ages even for very old rock.
The U-Pb method showed that some of the grains had ages of 1.9 billion year. This dates them to the time when the Inglefield Mobile Belt formed. The map below shows the various ages of local rocks, which agree well with these U-Pb dates for the grains from Hiawatha. (No other rocks in North Greenland have this age – it is unique to the Inglefield Mobile Belt.) Clearly though, this is when the rock formed – not the crater. These grains had not been changed by the impact.
The other grains showed a component with uranium-lead ages around 58 million years, at which time there was a ‘reset’ event which had partially melted the grains.
The argon method indicated ages in excess of 25 million years. The two grains with the best result showed ages of 58 and 60 million years. This agrees very well with the U-Pb method, which shows that ‘something happened’ at this time. This ‘something’ was the impact.
The Hiawatha impact is therefore dated to 58.0+-0.5 million years ago. To put it in context, this was 8 million years after the demise of the dinosaurs, caused by another, much larger impact.
This new age shows that the impact crater has nothing to do with the Younger Dryas, the ice age, or even the pleistocene. It existed long before the ice came. Did the organic remains date from the time of the impact? That is very much plausible: at this time the area was abundantly vegetated at the time and may have had conifer forests. The organic remains became part of the sediment washed out on the river floodplain.
This new age solves the problems that the young ages had: the lack of an ejecta blanket or ice core trace, the significant erosion, and the organic remains. It also leaves the Younger Dryas impact hypothesis without a smoking gun and without its strongest evidence. Unless new evidence emerges, this hypothesis may have to be abandoned.
Impacts
The asteroid caused a dramatic crater. It is perhaps the best surviving example on Earth of a large crater. However, the impact was too small to change the world’s climate or cause a worldwide extinction. That would have required a much larger impact as had happened 8 million years earlier. The effects of the Hiawatha impact would have been major across the local continent, but survivable further afield.
Were there such local effects? It is interesting that the crater is so close to the copper-gold belt which runs parallel to the rim. Did this fault open by the nearby impact? Copper and gold can be deposited by hydrothermal activity: the impact happened in a water-rich region, and the fault could have filled with hot water after the impact? This is of course speculative. The impact was also approximately when the Nares Strait opened. Did the impact break the final connection between Greenland and Ellesmere Island and triggered the activity of the Nares Strait fault? Nearby is an island, which was only recently revealed by the melting ice. It is now claimed by both Denmark and Canada. Perhaps, if this impact had not happened in this place, the two would not have separated and all of the region would now be Danish. It is just a thought.
The era when the crater formed was an exciting time in this part of the world. The volcanism in western Greenland related to the opening of the Labrador Sea occurred 60 million years ago. The paleocene/eocene boundary with its global warming event happened 56 million years ago, related to a flood basalt in eastern Greenland and the opening of the north Atlantic. The Hiawatha impact neatly occurred in between these events. What a time to be alive.
Final point
Dramatic results in science should always be looked at with suspicion, and with an eye to finding confirmation. This is how science works – checking, and checking again. In the end, the data will win. Sometimes, the extraordinary is true. Sometimes, there are changes to the interpretation. In this case, the Younger Dryas impact hypothesis lost out. But we are still left with a city-sized crater no one knew about, hidden in Greenland. The world can still surprise us.
Albert, March 2022
K. H. Kjær et al. A large impact crater beneath Hiawatha Glacier in northwest Greenland. Sci. Adv. 4, eaar8173 (2018) https://www.science.org/doi/10.1126/sciadv.aar8173
G. G. Kenny et al. A Late Paleocene age for Greenland’s Hiawatha impact structure. Sci. Adv. 8 (2022) https://www.science.org/doi/10.1126/sciadv.abm2434
Could it happen again?
Beautifully told story. Excellent!
Phantastic. Must have been a lot of work. Truly fascinating. Thank you very much!
Could it have any connection to this like triggering higher activity?:
“Isotopic dating indicates the most active magmatic phase of the NAIP was between c. 60.5[7] and c. 54.5 Ma (million years ago)”….
https://en.wikipedia.org/wiki/North_Atlantic_Igneous_Province
This is Mistastin, Labrador, about the same crater size, about 36 million years old.
Manson, Pocahontas Country, US, same size, is 74 million years old. If we leave Chicxulub out (much bigger) we have 16 million years between Manson and Hiawatha, and then Kamensk, Crater a bit smaller, 49 Ma. Before Manson, we have Steenriver, Alberta, 91 Ma. This would be 17 million years between Steenriver and Manson and 13 million years between Kamensk and Mistastin. So we have between 9 and 17 million years for craters this size, but some might be missing.
The other possibility is, that it was a time of “bombardement” as there is also Kara, Russia, with a crater size of 65 km, 70 Ma. That would mean 91 Ma, 74 Ma, 70 Ma, 66 Ma, 58 Ma, 50 Ma (Montagnais, Canada), 49 Ma, 2×35 Ma (Popigai and Chesapeake) plus Mistastin with 36 Ma, and some would be missing. After that they seem to be getting smaller which might mean a) they are generally getting smaller, b) more probably, the craters were smaller and seem larger caused by longterm erosion. Maybe both.
There’s a lot of room for science there it seems. It is also a very interesting topic besides volcanism.
https://en.wikipedia.org/wiki/List_of_impact_craters_on_Earth#10_Ma_or_more
There’s also another piece by Albert about Germany’s Nördlinger Ries and Vesta:
Vesta’s volcanoes: Dawn’s blast in the past
https://www.volcanocafe.org/vestas-volcanoes-dawns-blast-in-the-past/
Another masterpiece, Albert.
Thanks Albert, great article.
From the Vesta piece;
“By volume, Pallas appears just a tad larger. But Vesta is heavier than Pallas. It must therefore have a higher density. Indeed, the density of Vesta is measured at 3456 kg/m3 which is considerably higher than that of typical rocky asteroids.”
If one day, Albert, you’d explain how the density of other bodies in the solar system is measured, I’d be quite happy.
If that hit Earth At 35 km an second it woud boil Earths oceans.. and envelop Earth in a 20 000 C shroud of vaporized rock it woud become a hell that makes Venus look like paradise 🙂
Althrough souch Impacts only happened during formation of the Earth 4,5 billion years ago
There are two ways of measuring mass of bodies in the solar system. The most straightforward one is to send a probe there, and use Kepler’s laws and Newton’s law of gravity to determine mass based on orbital parameters of the probe (semimajor axis and orbital period). This is how Vesta was weighed, more or less down to precision to which we know the value of gravitational constant – 20 per million.
But for bodies which no probe has visited yet, you can still observe how they perturb orbits of other smaller bodies – small enough that their weight is negligible compared to the body you’re weighing. Again you use Newton’s law of gravity to calculate mass of bigger body based on how much it changes the orbit of the smaller body. (Of course, in fact both orbits are changed, and both masses affect this interaction, but when ratio is lopsided enough, the bigger body’s change of orbit is negligible and the mass of the smaller body gives a negligible contribution to the perturbation.) Pallas, while never visited, has passed close enough to enough smaller asteroids that it’s possible to infer its weight to about 5% precision.
Thank you.
Hiawatha metallic:
Any connection to Psyche (crazy name)?
“The asteroid Psyche is an example. It is a metallic object, 200 kilometers across.”
From Vesta piece.
Iron meteorites come from a protoplanet in the solar system that was destroyed by a large impact. Psyche might be the core of that protoplanet. Iron can only separate from the other elements when it is liquid and nuder influence of gravity. That requires a decent sized object. The iron sinks to the core, so to get it out you have to destroy the object. The object wasn’t planet-sized but bigger than asteroids.
So, where are the others? This is an inspiring piece. Meteorites. Invitation to excursions to Vesta, Ceres and the Asteroid Belt. Earth in the Solar System. What we see on Mercury, Venus and Mars plus the moon, must also exist on Earth, on the Ocean floor like Chicxulub, overgrown like in South-East Asia, possibly Thailand, or, like here, for the longest time hidden by a glacier.
A glacier hides in a meteorite impact, this is unique. It’s metallic, and people used it for tools.
Others like Nördlingen are more rocky, and people used it for building.
For centuries people used material from the Solar System and didn’t know it. They thought it was the centre made by God, and in a way it is a centre, the centre of fortune, lucky survival. But it regularly got birthday presents from the Asteroid Belt. The most unlucky guys in the Solar System were obviously the dinosaurs. Everybody feels pity for them although nobody wants to meet them.
South-East Asia:
https://www.science.org/content/article/glassy-debris-points-relatively-recent-asteroid-impact-southeast-asia
Only young craters will survive erosion, and only craters Jurassic or younger will be found in the ocean. It is uncertain whether Earth even had continents in the late heavy bombardment, land might have been exclusively as volcanic islands. Even Hawaii would probably be destroyed by a big impact, Iceland would maybe survive above sea level barely. So probably almost 0 chance of finding craters of that time which is when most of the carpet of craters on the Moon and Mercury formed.
Maybe the same thing for Venus, back in the Hadean it probably had a surface mostly covered in water with small islands. It probably evaporated fairly early though, before plate tectonics could properly start, which happened about 3 billion years ago on Earth so maybe slightly later on a Venus sized planet. Is hard to tell though because both planets have geologically young surfaces.
Great article, Albert. Two of my favourite topics in one!
And to celebrate we had the meteor impact north of Iceland:
https://interestingengineering.com/an-asteroid-is-spotted-before-it-slams-into-the-earth
This was a lovely read Albert. I know this is a volcano blog, but I would love to read more about impact events as well as they’re quite fascinating.
One question I have is whether the deep ocean can effectively hide or shield the impact event from creating shocked quarts? I have to imagine that roughly 4 km of water can effectively dampen some of the impact energy on bedrock and prevent shocked quarts from forming quite a lot. Alternatively, I would imagine that some of the water would reduce some of the ejecta into the atmosphere (albeit, in a tradeoff for more water being immediately pushed into the atmosphere).
To me, given the dearth of impact craters we see on the ocean floor, it would seem that unless you have a chicxulub size impactor, it’s difficult to get a crater that lasts at depth.
Depends on the speed and size of the impactor .. Impact Events are so powerful most larger ones does not seem any diffrence I think
Even If the 14 km wide Chicxlulub Asteorid have hit the deepest subduction trench.. at that time.. it woud not have made much diffrence I guess … only that the crater woud have been subducted today
An enormous ammounts of vaporized rock and ejecta woud have still been injected into the upper atmosphere and sent on ballistic reentry trajectories
But smaller impactors are defentivly stopped or slowed by a very deep ocean
Or ice. Cape York crater has still not been found. Or Willamette Meteorite. (deposited as a glacial erratic from wherever it originally was)
It was an enormous glacial mass there in the middle of the North American continent, going on in the West. It must have transported not too few rocks.
Wikimedia Commons/USGS
Oh. So bad. Try again:
The original Cape York meteorite was probably around 5 meters across. All significant parts have been found. That is smaller than the Chelyabinsk meteor, which was about 15 meters long, but it was around 5 times heavier than that meteor (iron is much denser than rock). At that size it slows down in the atmosphere and does not make as large a crater as one would expect. The Kamil iron meteor in Egypt was around 10 tons and created a create 60 meters across. Cape York was around 50 tons and may have made a crater 100 meters across. But because the different parts were found some distance apart, it may have broken up in the air already.
This is my favorite (possible) impact site, at Latitude 42.3396419022731 and Longitude -130.74216967772142 at a depth of 8347 meters in an ocean floor averaging 3800 to 4000 meters. Something big had to have hit here to punch that hole in the ocean bedrock. One day looking at the Hawaii earthquake monitoring maps, I happened to have stumbled across this pit in the bathymetric data. It needs scientific investigation.
Map?
Go to the Hawaii HVO webpage and pull up the monitoring map which has bathymetry on it then move north and a bit east from Hawaii to find the pit
Google maps doesn’t show what’s on the USGS page… Maybe there’s a data hiccup?
A bit larger for Geolurking. Really fascinating, Lake Agassiz:
Wikimedia Commons and USGS
It must have been totally frozen up there in the Younger Dryas. On the other hand there is the theory that the Younger Dryas might have been caused by an impactor (bigger than Willamette). It hasn’t been found so far, so the theory is what it is: A theory without evidence. 72% ocean, 10% mapped. This means: What we know is only pieces of a bigger puzzle.
That is what this post is about… 🙂
I was hoping that this post would have terminated that idea..
It pretty much put the nail in Hiawatha’s chances. The timing is far too off.
Well, concerning Hiawatha, yes. But there could be more. They didn’t even find the crater of Willamette. Come on, Albert, it’s more exciting with more theories, not fewer.
Very true…. But my Carolina Bays idea was shot to shit, and now Hiawatha. Its got to be something else.
Albert won this round on sound science. In order for the prevailing science to be defeated by better ideas… the science behind the new idea has to be profound and irrefutable. Hiwatha has been trounced.
Note: Cape York and Willamette meteors, though large, still fall short of the size needed for the effects proposed for a Younger Dryas impactor extinction event.
Geolurking, they also found traces in South Africa and Chile. An impactor in the forests in Brazil or Kongo or around the equator probably wouldn’t be found. Not in the Pacific Ocean before it is completely mapped either.
The same problem goes for missing volcanoes in those areas.
Albert is a wise man: “Unless new evidence emerges, this hypothesis may have to be abandoned.” In his piece.
Albert, you said in the piece that the grains’ age was measured 1) 58 Ma, 2) 60 Ma
Now I saw this (60 Ma), Skye:
https://www.sciencedaily.com/releases/2017/12/171214100851.htm
I hope you don’t mind that with the coincidence of dates I have to ask:
Do the Hiawatha Cratre and the old grains have to belong together?
These grains have not been found elsewhere in Greenland. But the Skye data is interesting. The data is slightly different from that of Hiawatha from the U-Pb data, but this seems based not on the debris layer but on the lava above it. So I do wonder whether the Sky debris is from Hiawatha. The locations were closer before the formation of the Atlantic
I was wondering whether the cratre is younger as Kwaer says here pretty firmly:
“The age of the crater is presently unknown, but an impact sometime during the Pleistocene is consistent with presently available geological and geophysical data.” (Before the chemistry of the grains came in)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235527/
The grains then being from a meteorite on the Altantic Ocean floor covered by lava from the NAIP and sand. Indeed they were very close 60 Ma, Simon Winchester mentions 15° longitude for 30 M years in his book “A Crack”. Alternatively from an airburst. Hiawatha being younger after all.
I think the theory might not be dead as I believe that a 60 M year old cratre would be more eroded with a travelling plate and changing climates.
So I would settle for two impacts if I were a geologist and go on looking for evidence.
The date for Hiawatha is now pretty secure. Kaer et al. favoured a time within the pleistocene but even their paper does no rule out an older date. And of course the pleistocene does not mean the Younger Dryas. That was always an unlikely suggestion for reasons given in the post. The Skye debris is dated to 60.5 million years ago but with some leeway. That is also the date of one of the fragments at Hiawatha. t raises the question whether there were two impacts at this time, 2 million years apart? Not impossible. In that case Hiawatha was the ‘big one’ and Skye a smaller event. Could it be the same impact? Yes, not full excluded, but only if that impact was Hiawatha. Either case, Hiawatha has nothing to do with the Younger Dryas. That theorey is dead in the water (or rather, ice).
This thinking comes from “lice and flee”. It happens not too rarely that us docs don’t find out what a patient precisely suffers from because he has two diseases, called “lice and flee”. And this is without 60 M years.
So, Albert, as I said under my replies to myself I believe the Crater is younger than the grains, based on the observations of Kwaer (under your answer from yesterday, 22.45).
More reasoning. A crater this old would be covered by ashes of the North Atlantic Igneous Province and other layers of, say, Aniakchak or Icelandic volcanoes. It would be more eroded as the climates change back and forth from cold to warm and warm to cold. The area might have been under water in between.
And there would have been found a few fossils between 58 and 60 Ma old. Paleontology might be the clue in the end as there must have been local havoc.
So, for me, it is not finished, and I certainly hope it’s not finished for geologists.
Call me old fashioned, but my studies of the Younger Dryas led me to conclude the collapse of Ice Dams and the floods of fresh water pouring out from northern USA into the Atlantic (carving out the Badlands, etc) were the cause of the reversal of the post-glacial warming trend. These did not happen in one go, there were several over time.
The giant floods effectively smothered the circulation of warmer waters from the Gulf and temperatures went into reverse for a number of years until the effects wore off.
Bob’s your Uncle: Younger Dryas. job done mate.
I don’t see the need for an impactor, and I have my suspicions that even had one unfortunately plopped into the North American continent at the time, it would have made little difference.
It is also why I also consider the doom-mongers incorrect over their predictions of the collapse of the Gulf Stream (I can’t type thermohaline cycline thingy whatsit, sorry) due to a fresh cold water leaking off Greenland. The quantities are incomparable between the Dryas and now.
Interesting thought about the fear-mongerers and the gulf stream. They made a film once for German TV with all the ice of The North melting in a very short time and then flooding the islands. Fear-mongering makes good films. Take Roland Emmerich. Exciting stuff. Most people love fear for some reason. Plus dying folks, mososaurs devouring girls, dinosaurs chasing children. Murder. Sitting in an armchair with beers and a bag of crisps watching natural desastre or crime.
Reality is much slower though. I read a paper which said that Cycle 26 could produce a Solar Minimum and a small glaciation, starting in 2030. That’s not fear-mongering though. A paper with calculations.
Very interesting indeed. Thank-you Albert.
Bored Wednesday afternoon musing – if a very large meteorite just happened to slam directly into the centre of a large active volcano (say Kilauea), what might happen?
Let me guess. Kilauea and Big Island would be completely flattened. The effects of the meteorite impact would overshadow everything. You said large.
If you mean large as in 1 km crater then it would probably set off a major eruption, even fluid basalt under those conditions will probably explode or at least would erupt too fast to call it a lava flow. Most likely the impact crater would be unrecognisable almost immediately.
If you mean large as in Chixulub sized then the fact it is hitting a volcano is of little importance. Chixculub could have hit the Deccan traps and even then the volcanism would be of little additional damage, just that the crater would probably have filled in afterwards and been entirely hidden. I suppose it is not impossible that some LIPs were initiated by impacts just they are not exclusively formed that way.
There was talk here once about an impact hitting Iceland and setting off a flood basalt. Basically the conclusion was an impact big enough to excavate down to the deep rift would be a far bigger event than any eruption it might cause. Impacts are literally out of this world in the amount of energy involved, the only thing comparable are nuclear weapons. Eruptions can compare to small impacts (or to nukes that actually exist) but there is a limit because of pressure and fluid physics, an impact turns whatever it hits into plasma at the density of a solid but completely unconfined…
🙂
Agreed. I read though a few days ago, that a nuclear bomb would do little to a volcano, unless it is highly active. But it wouldn’t trigger an eruption in Yellowstone, thank God. Let’s not work this out more, please.
There is a difference between a nuclear weapon we have build and one that could exist. We could build one as powerful as a VEI 8, or an extinction level impact. We cant practically do that but there is no fundamental reason it is impossible.
The biggest nuclear explosions are type 1a supernovae, which have energy sufficient to turn our entire solar system into plasma at solar escape velocity multiple times over.
No limit the size of nuclear tests.. as Chad says.. and wow This is really my stuff 😆
The dream for me on my 27 th Birthday is a New Tsar Bomba Test with same yeild as Chicxulub 🙂 and let test it on the Antartica Icecap
At 300 million X the original 1961test it Maybe not very diffrent at all from the real KT impact.. whole mountain rangers woud move like you threw a rock in a pond .. the fireball maybe almost 2000 km wide and visible all over Sourthen Hemisphere.. wont be any mushroom cloud at souch yeilds.. the explosion is much bigger than the atmosphere is tall.. the south hemisphere woud awoke to false sunrise
At souch high yeilds it Maybe set much of the atmosphere on fire I guess or from all thrown up materials it Will set on reentry trajectories
I dont even know what a nuclear test 100 times bigger than Tsar Bomba woud look like 🤔 But There woud be No mushroom cloud at souch enormous yeilds
Impressive stuff like bringing a piece of the suns center To Earth
And Nukes are even much much hotter than the center of the sun
Well Tsar Bomba and Castle Bravo looked very diffrent from the much smaller Hiroshima
What woud be worst
A New Chicxulub Impact or a Nuclear Test with same yeild as chicxlulub?
Both are bad but not same physics exactly
My dream is that nobody touches Antarctica. If they want to try out bombs they should settle on Venus, would only add to the damage there.
Right … or Mars
On Venus the nuclear fireballs will be very intense because of their High atmospheric density
Strong quake off the coast of Japan:
https://geofon.gfz-potsdam.de
Don’t speculate!
https://www.jma.go.jp/bosai/map.html#5/38.407/143.189/&elem=warn&contents=tsunami&lang=en
According to the US Tsunami Warning Centers, there is no tsunami threat: https://www.tsunami.gov/.
With an earthquake depth of 63 km, that is not surprising.
Preceded by a 6.4
https://earthquake.usgs.gov/earthquakes/eventpage/us6000h518/executive
You know, that was just what I was wondering about. Purely as an gedanken experiment, of course.
There was a smaller one around 6 before, so it might be over.
They have a probelm with getting rid of the cooling water and want to send it into the Pacific Ocean, diluted. The Chinese don’t like the idea:
https://www3.nhk.or.jp/nhkworld/en/news/backstories/1938/
Campi Flegrei did a M3.5 today. Biggest quake since the 1980s.
https://ingvterremoti.com/2022/03/16/evento-sismico-md-3-5-in-area-campi-flegrei-16-marzo-2022/
https://www.livescience.com/giant-jurassic-pterosaur-scotland
Seeing as how there’s nothing happening on earth…
https://www.jpl.nasa.gov/news/nasa-extends-ingenuity-helicopter-mission
Don’t forget the rollout of the Artemis 1 SLS stack for the first time this evening (UK time). A milestone we thought may never arrive. https://blogs.nasa.gov/artemis/2022/03/16/artemis-i-stack-ready-to-rocket-and-roll/
That is a milestone. Maybe much needed now that Russia will no longer launch spacecrafts for others. But SLS is horrendously expensive. NASA will only be able to afford one launch per year
They have the option of using SpaceX. Not just Starship (which will probably take ridiculously and unnecessarily long to be human certified) but also Falcon Heavy, which is already human rated. Would take multiple trips but you could launch 8 fully expendable FHs for the price of 1 SLS, or probably twice that number if reusing boosters.
Actually, maybe human rating Starship might not take that long, it is the landing vehicle for Artemis, and NASA defended that successfully agai st a lawsuit by one of the other lander teams. Maybe Jeff Bezos should actually try to get something into orbit before trying to make a human rated moon lander 🙂
NASA tv Live “Awaiting first motion”
The success of Ingenuity has spurred on development of the successor Mars Science Hexacopter and now a MAHD method of delivery 🙂
https://arxiv.org/abs/2203.03704
Interesting article about the enlargement of lakes in Kenya on the Great rift and elsewhere. Looks like a variety of causes at hand but no definitive answers
https://www.theguardian.com/world/2022/mar/17/kenya-quiet-slide-underwater-great-rift-valley-lakes-east-africa-flooding
The most important passage of the piece:
““If we go back in time, the Rift valley lakes have had higher levels. What we are seeing now is not something new.” Sean Avery, a hydrologist who has lived in Kenya since 1979, has pointed out that the current level of Lake Turkana is no higher than it was in the 1970s or in the 1900s.”
So on the topic of younger dryas event, I’ll put forward one view I have.
In large part, I don’t think there was an impactor, there just was a lot of abrupt climate that caused lots and lots of chaos.
Complex systems such as climate tend to operate in a relatively stable manner between various constraints. But once those constraints get broken, you get a phase transition, which results in a lot of chaos until the inputs into the system find a new stable equilibrium.
In short, very abrupt changes in temperature and climate that occurred around this time was likely too fast for a lot of life to adapt to. We know there were likely some very large fires in north america. While this could easily be caused by an impact event, I tend to think it could have just as easily been a product of the climate change of the time. If environment of north america suddenly transitioned from a relatively wet environment into a much dryer environment (or a large drought), it would make sense that you would see massive fires occur. The previously wet forests would have built up massive stores of potential fuel that never burnt because it had always been too wet for a real forest fire to do any burning of underbrush.
Combine that event with the stress from lots of other massive changes in climate that happened on a relatively quick timeframe (geologically speaking) and I think this easily could be enough to explain what had happened. That being said, clearly could have been due to many other causes, and as with many things, this was not just the product of one event.
abrupt climate change*
I think the thing that is never ever considered is that events of thjs magnitude can be any combination of things as a cause. Trying to say mass extinctions are only caused by one thing then trying to find evidence of that thing at every case will always result in a correct byt very biased answer. Some extinctions were caused by LIPs, some by climate change as a result of continental configuration. KPg was caused by an impact, but also there was a LIP in progress, maybe it would not have been as bad if only one had occurred.
In the case of the Pleistocene extinctions it has to be said we are undoubtedly involved. Any attempt to say otherwise is just being unrealistic. There had been many interglacials, presumably many ‘Dryas events’ in turn. Rarely did animals totally disappear. But this one occurred in the presence of cosmopolitan Homo Sapiens, and literally almost everything disappeared…
It is not only the obvious places either, the Americas and Australia. Africa and Eurasia lost a lot of megafauna with the spread of intelligent Homo, just much earlier, and not quite in totality. Hyperspecialised big game carnivores like the Machairodontinae (sabertooth cats for the rest of you 🙂 ) sequentially went extinct quite rapidly when our genus turned up on the predator scene, half a million years ago in Africa, about 150,000 years ago in Eurasia with one exception, and at the end of the Pleistocene in the Americas. The extant Panthera cats are not obligate megafauna specialists so could coexist with us though not easily. I think people today are so removed from this that they have truly no idea how dangerous we are as animals, give us anything sharp and we are killing machines of the highest calibre, and we are also primates which are a rather characteristically violent and agressive group of animals.
Exactly everywhere where Homo Sapiens vent during the Pleistocene.. the Megafauna died out When humans came there
Australias megafauna where pretty much terminated by the arriving humans including megalania
We are indeed the most dangerous species that have ever evolved .. better we move to Mars and leave Earth in peace
You don’t need to send anybody to Mars. Death penalty for killing wild animals that were not bred before would certainly do the job. It would mean giving wild animals the same rights. I don’t see a consense for this though, esp. in China.
Sending to Mars is a fantasy. This is concrete. Concrete means protection of wild animals and their habitats including the Amazon, Swedish or Finnish forests. It means end of wrapping paper, high prices for wooden floors, furniture, toilet paper and Kleenex and so on. It means boots on the ground for wild animals and their habitats. Might happen one day when enough people are thoroughly disgusted by Homo aka stultus.
There is the book “The Sixth Extintion”: I think Chicxulub was the Fourth and Popigai the Fifth (only bigger ones, there were more). This means mankind is a meteorite impact for wild animals and their habitats, nothing less.
This also means setting new viruses free by taking down their hosts and habitats. And the answer can then be seen as a balance with some good will or bad will, depending on interpretation. There’s a good older piece in the Guardian about chicken farms in China moving into the Wild Forest.
Megalania, properly Varanus priscus, was not the bloodthirsty monster it is in the media. It was literally almost a model image of a Komodo Dragon but somewhere between 50% and 100% larger. Komodos are potentially dangerous but generally no threat. Megalania was probably just the same, if you were near a carcass they would probably pay no attention to you. Thylacoleo on the other hand, not the sort if thing you would want to encounter unarmed, though I doubt it would have actually seen something our size as prey, it was a real big game specialist and sort of overengineered to attack anything its own size or smaller effectively.
Quinkana was probably the one that would have been the most powerful, basically a sizable saltwater croc but with long legs, quite at home on land and probably entirely terrestrial or at least much more than modern crocs are. It also had teeth that were serrated, thing was basically like a land shark 🙂 it js a shame it is very obscure compared to the other two, at equal length it was probably significantly heavier than megalania and with a much more powerful bite. Fossils of both megalania and Quinkana have been found inbetween lava flows of the Nulla province in Queensland, still active, to link back to volcanism.
That being said there isnt exactly any recollection of monster sized killer reptiles terrorizing people in the Dreamtime stories, which are otherwise quite realistic and describe a lot of real events pretty accurately. So maybe they ended up on the menu instead…
So Megalania were typical Australians and Thylacoleo were more like the Russian army? While Quinkana makes me think of the New Zealand rugby team.
Funny, Albert. I’m not talking about the Younger Dryas anymore, enough readers having given plenty of reasons for it. But I believe the crater is younger for the reasons mentioned above. I don’t think that there is anything in the world that travelled with its plate being accomoanied by a LIP and then ending uo unchanged. So, I won’t believe that the crater is 58-59 million years old.
Pilanesberg is 20 times older and also went through a LIP. It has been at the surface for almost as long as Hiawatha. It is not unprecedented. There is a big gap in the ring on the eastern side. It looks like an ancient river and may well predate the ice. Before the ice age, there were large lakes in central Greenland, with a big flow channel towards the northern coast. I was wondering whether the system connected to that.
You certainly have a point with Pilanes.
I guess you could say that Albert. Should say Quinkana was only found in the far north as modern crocs are, which also did exist at that time too. Megalania and Thylacoleo were found continent-wide, probably the mammal was much more prominent in the south where it was very cold in the winter.
The thing is realistically all 3 could re-evolve, there are some pretty big varanids still extant in Australia and also now a new swath of megafauna (cattle and buffalo, probably camels too) to encourage evolution of a new apex predator. Crocodilians also have a persistent habit of returning to land, it has happened many times in their evolution and at least once from every line of their lineage, and rather rapidly if a niche is vacant. Even today many crocodiles can gallop and all have 4 chambered hearts and unidirectional lungs of an active terrestrial animal.
Anyone who has cornered a possum will know it us only one size down from a drop bear. Possibly having big cats now exist in Australia (not leopards but literal massive feral cats) will thwart the evolution of Thylacoleo 2 but that might not stop them trying… 🙂
I read the geological period Dryas is named after the plant Dryas octopetale ( funny, I always assumed it was the other way around …. !), because of the quantities of pollen found in core samples. In the Alps this arctic-alpine species blooms within weeks after snow has molten.
Mountain avens is the national flower of Iceland.
Wikipedia
Pretty, thank you.
I saw something a while back on the Bangui Magnetic Anomaly, it implied an impact crater with an outer ring that stretches out into the atlantic southwestward. It would certainly be the biggest impact on earth, since the moon’s creation.
From wiki:
‘The Bangui anomaly is bounded to the south by the Walvis Ridge, the north by the Cameroon–St. Helena volcanic line, and to the west by the Mid-Atlantic Ridge. It is shaped approximately as an ellipse 700 km × 1,000 km (430 mi × 620 mi) in size. It has three sections, and the magnetic equator runs through its center. It has a short axis diameter of about 550 kilometres (340 mi), and its amplitude varies between –1000 nT at ground level and –20 nT at satellite altitude, about 400 kilometres (250 mi).[1] Its features include a Bouguer gravity anomaly of −120 mGal, a topographical surface feature shaped as a ring of 810 km (500 mi) diameter, rock features of Late Archean and Proterozoic periods in the central part of the anomaly, granulites, and charnockites rock formations supplemented by granites at the lower crust level, and greenstone belts, and metamorphosed basalts seen as rock exposures.[2] A zone of thinner crust bounds the anomaly to the north and a zone of relatively thicker crust is on the southern edge.’
Also did we ever find out the origin of the Australasian tektite field?
That might be Bolaven:
https://www.syfy.com/syfy-wire/impact-crater-of-massive-ancient-meteor
https://www.quantamagazine.org/rumbles-on-mars-raise-hopes-of-underground-magma-flows-20210201/?fbclid=IwAR1o06i_RcT96qPKwD27PlQhRRCppFwAW5Ym_rATU9U5V9qqXowk21UhfcU
Good Article
Yes, interesting. Good pictures. I like it when they colour them as it is sort of exhausting to look at reddish pictures.
Very interesting. 60 km is a plausible depth for magma on Mars. The data is not conclusive: a few more events will help. If it is magma, the next question is what makes it flow. Is magma accumulating, or are the rocks above shifting a bit?
There is a new flurry of earthquakes on Reykjanes, one at Fagradalsfjall and another more powerful next to Grindavik. Not at pre-eruption levels yet but it has been about 3 months since the last intrusion and that was 3 months from when lava stopped erupting, so a bit of a pattern.
I remember there being mention of significant magma accumulation at depth under this part of Reykjanes. The eruption that began a year ago 🙂 and the intrusion in December both came from from a source that rose up under Keilir, that might be why they were weak, but there is nothing saying that more deep conduits cant rise up under Fagradalsfjall itself and erupt more directly. That would probably lead to a larger and more intense eruption, and maybe a more persistent one.
Grindavik is probably quite doomed now, seems very likely an eruption will take place on the fissure swarm running right through it sooner or later.
That swarm near Langjokull stopped, maybe it was not a volcano after all 🙁
That’s definitely a worrying cluster near Grindavik.
If that becomes a persistent EQ swarm area, it’d be even more worrying.
Think it has already been a long persistent swarm for at least 2 years now, and magma has risen under the area at least once in that time and probably ever since 2020. There were persistent swarms at Fagradalsfjall for years before it erupted too.
In this quieter period some of you may be interested in this:
“Slab-derived devolatilization fluids oxidized by subducted metasedimentary rocks.” https://www.nature.com/articles/s41561-022-00904-7
An interesting take on the Tonga magmas.
Looks like another small swarm of earthquakes around the south slope of Mt Hood. wouldn’t be suprised if this one erupted sometime this century.
Is it possible PETM and/or NAIP are related to Hiawatha Glacier Crater?
PETM is related to NAIP flood basalts
There was a video today about that exact question. Anton Petrov on youtube.
I think stuff like that should be investigated, especially for events of this magnitude and short duration. Even the biggest VEI eruptions are unlikely to impact this much, and flood lava events are not really fast enough long term, or likely to reach the stratosphere. Impacts though are instantaneous events.
Hiawatha probably affected the nearby volcanism. NAIP might have been more like Iceland than Deccan Traps, not so intense as a lot of other LIPs, and nothing that probably would have been so extreme to produce the PETM. An impact though, well that could have set it off directly or induced extreme volcanism.
NAIP was a Big LIP over a short timescale .. But its thulean lava plateau have been eroded away
But almost certainly had monster flows, one paper a few years ago describes VEI 8 pheratoplinian eruptions from that event
Faroe Islands remains of that LIP plateau have some gigantic Aa flows exposed in outcrops that spann the entire Island group and are 60 meters thick so events that dwarfed Laki thats for soure
But Central Atlantic Magmatic Province was more Severe
Just folliwing along….
Halema’uma’u is flowing like crazy now 🙂 and many upwelling sites too
Beautiful piece on Hiawatha crater, thank you Albert!
On the elevation graphic, I see what look like two erosional chasms to the south. If that’s what those are, it seems to me that the impact would have had to occur many millions of years ago, a good fit for the dating you cite.
As for the Younger Dryas impact theory, I’ve long been conflicted. My main issue is that the evidence often cited seems to have date issues. I have no problem believing that an “impact” event could have occurred without leaving a crater (an airburst due to low angle of incidence, especially of over an ice sheet or ocean) but that would need the evidence of spherules, etc, to be a bit more definitive IMHO.
Looks like there was a bit of activity in the Azores between yesterday and today at the São Jorge volcano in the Azores about 17 by the looks of it ranging from just under 1km to 15km deep.
From what I can tell it looks like it’s in a line, this volcano is classed as a fissure vent isn’t I think so could this be signs of activity starting to pick up in the Azores again?
This might be interesting to you all? https://www.sciencedaily.com/releases/2022/03/220314154424.htm
Is continental collision (e.g. in the Himalayas) different to plate subduction?
You asked, Clive: Is continental collision (e.g. in the Himalayas) different to plate subduction?
Well it is a combination as the authors are writing themselves. First, the Tethys Ocean subducted, then the (older) Indian Plate dived under the Asian Plate, possibly to a depth (link) of 200 km. But not all is subducted. Some of the material is pushed up further inland, also nicely seen in the Andes where an oceanic plate (Nazca) dives under a continental plate. Also the collision of Gondwana and Laurentia 250 Ma led to the subduction of an ocean and continental mass, but also folding to the same extent with the result of the Transpangaean Mountain Range. It is the classical process for orogenies I think.
From your link:
“This says that we shouldn’t be looking at continental collision and oceanic subduction as two different things — we should be looking at them as the same thing with somewhat different flavors because geometrically, they look the same,” Klemperer said.
Another link about subduction depth, abstract (sufficient for explanation):
https://www.sciencedaily.com/releases/2010/05/100528101552.htm#:~:text=Geological%20investigations%20in%20the%20Himalayas,of%20at%20least%20200%20km.
Nice art of the Chicxlulub Impact althrough in real life it woud be even brigther as the impacts hot ejecta plume was many times hotter than the surface of the sun .. You woud get retina damage by looking at the impact from distance ( brigther than the sun )
Chicxulubs reentering ejecta transformed the atmosphere into an oven over large part of the planet .. Atmospheric firestorm as all the Reentering ejecta as Chicxulubs superhot ejecta plume falls back on the upper atmosphere. Trillions of mini meteors fills the upper atmosphere radiating heat towards the ground, Earths atmosphere turns into an oven glowing like a kiln furnace. Most of the ejecta burned up shedding its heat to the atmosphere
The heat pulse was worst in the Northen Hemisphere That was engulfed by continent sized forest firestorms there is a global soot layer from the KT boundary.. so large parts of the biosphere burned.. wildfires everywhere
Chicxulub also created a serious Impact Winter with global vegitation dissapearing for a few years in global geological layers, the food farmine is What doomed most of the KT larger species during the Asteorid Winter
Whatever happened that day .. woud be quite a sight to see 🙂 But No timemachines yet
Well entire continents woud look like the Hamburg and London firestorms hours after the impact .. really scary
North America was badely hit with all vegitation gone in geological layers from the KT boundary
If the Asteorid was a bit larger perhaps not even the mammals woud have made it
I read a description of policemen outside in the morning of the San Francisco Earthquake 1906, very plastic. The ocean came in, the buildings started walking and then collapsed. The fires started a bit later.
I think the San Francisco Earthquake gives an idea, we just need Albert to put in a multiplication factor.
Indeed Chicxulub woud be an insane sight to see in a time – machine the entire planet was burning as the ejecta and impact plume fell back on the atmosphere and reeentered
Wildfires everywhere and better to be in a lake To shield your skinn against the atmospheric heating
The skies fills with meteors as the ejecta comes into the atmosphere turning it into a Firestorm
The skies became oven hot
If you could see it, it would be the last thing you would see!
Any veracity to the idea that large impact events can instigate antipodal flood basalts? I think there’s even been insinuation Chicxulub initiated the Deccan Traps, though I’m not quite sure how antipodal that location would’ve been at the time of impact.
I always thought this idea seems rather unnecessary as the mechanics of a rising plume head unleashing a torrent of magma makes plenty of sense on its own, meaning we don’t need another catastrophic event to explain it.
Any thoughts Albert?
You forgot about the massive earthquake made from the impact. And all of the tidal waves made like some meteotsunamis, by the initial atmospheric shockwave as it race all over the world. Truly a very bad day for Earth.
Timemachine
Best to see it from the surface of the moon ( woud be a very very very bright flash for many minutes ) brigther than the sun
On Earth you coud be in Europe or Asia and Watch the ejecta firestorm as the Chicxulub materials fall back on the atmosphere
Funny. You found a way to watch it. Only problem: You wouldn’t be able to return for a long while.
Many large dinosaurs where clearly warm blooded and had rather mammalian or avian in evolved features
The endothermy became their nail in the coffin during the Asteorid Winter as they needed alot of food, and the food dissapeared during the Impact Winter When the biosphere production shut down for a few years
Crocodilians surivived with cold bloodedness as they dont need to eat alot
Warm-blooded? Mammalian? Avian yes, but mammals were separate, very small, could hide like a mole or mice. Dinosaurs had air chambers in their bones, otherwise they would have collapsed under their own weight. I believe the air chambers burst together with the lungs.
What he means is dinosaurs would have been much more like mammals than lizards. And actually most probably would have been more like mammals than birds too, only the smaller bipedal dinosaurs would have been obviously birdlike but the massive 20+ ton sauropods and hadrosaurs would have been more like mammalian megafauna, very solid powerful animals. Large theropods probably would have been surprisingly un-birdlike too, most would not be able to run safely as adults, and had crazy proportions compared to small theropods (small arms, very thick necks and huge skulls typically).
Remember birds are hyperevolved towards flight, with no exceptions. Even flightless birds like penguins and emus still show the adaptations, it us rather fundamental to their body plan. Imagine trying to reconstruct an elephant or a lion from bones where the only live mammal you can use as a base is a bat, that is basically what we have to do with dinosaurs.
The tsunami is always forgotten:
1. Closer specimen died of the explosive forces.
2. Others, also further away (the European and African coasts being must closer) drowned in the hugest tsunami ever seen. Some, washed up in river beds, are found together (Hell’s Creek)
3. Many who survived starved afterwards (global cold, food crisis).
4. Survivors were further away and somehow adapted to oceans and food there.
The rat would survive today too, being able to live in water and on the ground and underground and being really omnivorous, besides very fertile.
Rats are actually vety vulnetable, rodents have to gnaw or they die, so require a lot of food. Rays in particular are also rather acclimated to our living conditions and would not survive in the wild without us. Its a bit of a meme that the world will end up full of giant rodents in a post extinction, they are a rather highly derived and specialized group compared to many other small mammals.
A post anthropocene ecosystem is surely going to be one of the most unique ever in the history of life. Most certainly any prediction of what will inhabit it will be very far off, honestly just about anything. If we get really crazy about gene editing and de-extinction then the options are limitless, it will be insane.
How about the raccoons?
Many other groups where also badely hit during the Asteorid Extermination
Chicxulub was Severe enough that only small generalists or cold blooded low metabolism giants made it .. almost all large land animals dissapeared
Only one group of birds made it through too that became the ancestors of todays bird – fauna
Makes you wonder how the birds survived. They have very high metabolisms.
Apparently the survivors were all from aquatic environments, and omnivorous. Also likely very small probably not any bigger than a sparrow. Maybe this trait is why so many bird lineages today have ties to water, not nearly so many Cretaceoys birds did, nor did pterosaurs
Great idea. Most birds survived because they were able to dive?
But then there is “wonder-chicken” (Cambridge). Maybe it belonged to the ducks though.
SO, the oceans seem to be the saviours of life.
Apparently the survivors were all from aquatic environments, and omnivorous. Also likely very small probably not any bigger than a sparrow. Maybe this trait is why so many bird lineages today have ties to water, not nearly so many Cretaceoys birds did, nor did pterosaurs
In this piece you find the oldest zircon found so far in West Australia, courtesy of John Valley, U Wisconsin, 4.374+/-0.006 Ga.
https://news.wisc.edu/oldest-bit-of-crust-firms-up-idea-of-a-cool-early-earth/
After Albert wrote a lot about the oldest crust on earth in South Africa, Greenland and around Hudson Bay it seems really inviting to me if you added some about Australia.
Four areas, West Australia and South Africa sitting close together, and Greenland plus North Canada, possibly sitting next to them then seem to be the beginning of firmer continental crust. And Valley says that the
study they have done there proves that the Earth was cool enough to hold oceans before 4.3 Ma.
Is the Saõ Jorge swarm still going ?
Albert, btw.,
an extinction event, at least a local one, caused by the Hiawatha impact 58.,,, Ma would possibly not be seen as life wouldn’t have recovered that fast after Chicx. (8 million is no time in geology and paleoontology). As birds survived and possibly water-adapted birds, it might be possible that there are next to no fossils. Birds do not fossilize well, the same goes for bats, fragile leg and wing structures.
So, a small extinction event cannot be excluded if nothing is found, esp. in an environment like Greenland. It seems much easier to me to find fossils of the likes of the Sib.Traps as they were going on for at least one million years.
S.th. else seems interesting to me: If there was an impact around 58 Ma without traces of an extinction like bigger fossils the dinosaurs were definitely gone by then.
Jesper
It’s so easy to feel sorry when seeing this. But then man came to make pictures like these. This one is from Christian Darkin, he has made amazing and very lovable pictures:
https://fineartamerica.com/featured/2-sauropod-dinosaurs-christian-darkin.html
Sometimes I don’t like mankind. What I don’t like is force, also mental force, greed, envy and also mass enthusiasm like there was for WW I, hysteria, exaggerated fear, superstition and other particularities.
But then I see a picture like this, and I’m glad to see the good side of mankind. Mankind is writing the story of the planet and also other planets, stars and suns. Mankind gives ammonites and dinosaurs a history. Without mankind they would just be gone, nobody would remember them. Mankind found them, described them, did research on them and pictured them. Mankind made them eternal.
From the photo, a question came to my mind: Is it precisely because of us that there is no more such gigantic animals? And the rhinoceros, elephants and large whales might go next.
No, these preceded us by around 65 million years. Not guilty. Not guilty for the mammoth either (glaciation). Guilty though for plants and animals that live today.
Open List of extinctions on wikipedia which goes down in age. First: Humans. Second: Humans. It hurts. All the others were meteorites, climate cooling or volcanism.
Well, I wasn’t blaming us for the demise of Dinosaurs! I just meant that when a very effective predator of our size arrives, it seems that it will first kill almost all the larger animals.
Azores swarm keeps going? Any chance for an eruption? The swarm is not very Intense althrough quite strong quakes .. But not the intense dense hamering of small quakes that signals a magma intrusion
Aside from the Azores swarm, theres been a swarm near Mahagnao volcano in the Philippines, not sure if that’s volcanic though to be honest. Seemed to be linked to a M5.3 that occured yesterday and subsiquent earthquakes have been varying in depaths from 35km to near the surface.
Lakigigar
Studying some maps I got to the following conclusion: Greenland 60 Ma was still tightly connected to Eurasia, on the western side thought there is a tail of the Atlantic Ocean opening up.
NAIP, on the northern end of the Large Low Shear Wave Velocitiy Province (LLSVP) Tuzo is very close or under Greenland. So, it is very well possible that the meteorite is closely connected to the NAIP as Chad said as well.
On the other hand the CLIP (Caribbean) with a spreading ridge was finished 3 million years before Chixculub hit, and there was no new LIP as far as I know. Therefore the co-existence of LIP’s and meteorite impacts could also be a coincidence.
10 million years later there are two openings of the Atlantic Ocean west and east of Greenland, and there are probably higher sealevels. If or how the PETM might have been connected to this I couldn’t tell.
As the end-Cretacious temperature was at a low though whereas the meteorite impact and the Deccan Trap eruptions coincided, after being high around 90 Ma a connection might be strongly disputed, I won’t look this up now. A few million years after Chixculub and Deccan the temperature rose again though, there were no ice caps at the time. Therefore there might be a rebound effect after significant cooling.
If a gigantic impact like Chixculub, accompanied by a LIP doesn’t cause a second LIP in the surroundings I would believe that a significantly smaller impact couldn’t be connected automatically to a LIP.
Bags of questions for research.
I think that the NAIP on the northern end of Tuzo is mainly due to a deep mantle plume. Therefore it doesn’t need the meteorite for an explanation.
https://www.youtube.com/watch?v=rxeRdZ0gn8k
A real-time simulation of a, to simply put it, “what if Chixculub impacted Earth today in the same area as 65 mya”. It shows that, in human time scales, an impact isn’t an instant (though geologically, it is a thunderbolt). Quite shows the true ‘impact’ of such an event.
Insane stuff the plasma fireball after the impact is a 600 km wide and high little star and at 20 000 C so it will be waaay brigther than the sun .. it expands quickly into a plume
It wasn’t like this. 75% of species died out, 25% survived. With a heat wave of 250°C and the globe burning globally no creature would have survived. This is sensational scare-mongering. The continents were also closer together, the Atlantic Ocean narrow.
With the scenario pictured there wouldn’t be fossils.
The impact ground zero itself woud have generated temperatures of up to
18 000 c to perhaps up to 24 000 C forming a rock vapour plume by its own kinetic energy and Thats seen as the impact flash and the boiling ejecta plume
If you where anywhere close near To ground zero it .. you be incenirated on the spot and turned to plasma as well
The atmospheric heating by Chicxulub is debated all the time .. But it was alot of ejecta that was sent on ballistic reentry trajectories heating up the upper atmosphere as they comes back in as mini meteors the uppermost atmosphere Maybe been heated to perhaps 2500 C
The ground temperatures far away from impact is unknown .. But the biosphere did burned over large parts of the planet and That requires ground temperatures of over 550 C for some time at least .. the ejecta high above had a oven effect
The video gets many things right althrough better They make more research
550 to 700 C are likely figures for global ground temperatures for the Chicxulub atmospheric heating by its Reentering Ejecta that comes back in as trillions of shooting stars after the impact .. To allow large parts of the biosphere to burst into flames and form that KT soot layer
The Sourthen Hemisphere May have been cooler 250 to 300 C
The Asteorid Impact itself generated 20 000 C much hotter than the surface of the sun
How would anything, even small omnivoric scavengers, survive ground temps that high? Were all the survivors underground at the time this happened or underwater?
Seems like we were very close to sterilizing the planet again, at least in terms of continental surfaces.
They went underground or in water .. soil is a very good insulator
This is insane fear-mongering for making money with gullible young people. It doesn’t belong in a scientific blog, my sympathy assured, Zach.
Snakes and pterosaurs wouldn’t have survived, no single mammal, no matter how deep inside earth. Even the shark wouldn’t have made it in a boiling ocean, nor the crocodile.
75% of species were mainly the dinosaurs, so it probably had to do either with their air-chambers or with not finding enough food for their size. It might also have to do with their habit of leaving their eggs alone, contrary to birds. And snakes? Crocodiles eat cadavers, snakes can live without food for a while.
Rodents though obviously have found food, also avian dinosaurs and the predecessors of today’s birds. It was significantly different.
If it weren’t nobody would have even thought about the possibility of the Deccan Traps.
There are completely intact fossils in America! washed up in rivers. So I say, there were no huge fires, but a huge tsunami instead. Worldwide fires would have destroyed everything and every single species.
This wasn’t even as bad as the Permian-Triassic extintion. This was different. Sensationalism isn’t good.
Chicxulubs atmospheric heating was enough to boil shallow lakes and small rivers
But the oceans are too massive for an impact of that size To boil .. they did not boil during KT
To boil Earths oceans You needs a 100 km wide impactor and to boil away Earths oceans You needs a 500 kilometers wide Impactor
Higher speeds works well too
Chicxulub impactor was around 14 kilometers wide
Jesper
I’m nice.
They don’t even know precisely why the dinosaurs died out, and mainly the dinosaurs. What they know though is that the dinosaurs had already started to die out before which means they were old and, although gigantic (some) feeble.
The extinction of the dinosaurs is a topic of research and not a pizza-festival. The avian dinosaurs died out about 15 million years later. No meteorite, duh.
That is a myth that dinosaurs were already going extinct before the K-Pg boundary. Until recently there were no bonebeds of exactly the age of the impact but one was discovered in the Hell Creek formation, it has a great number of exquisitly preserved fossils ranging from dinosaur feathers to 3 dimensional fish, and half of a Triceratops with the skin still attached. Apparently every dinosaur known from the formation has been found there in some form.
The site is called Tanis, and it was created by gigantic seiche waves in a river as the shockwave went through, a magnitude 11+ earthquake about an hour after the impact. There are fossils of sturgeon that were violently impaled on each others osteoderms and have microtektites stuck in their gills…
So yes dinosaurs and the environment in general were completely fine up to the very last moment. Maybe not in India, but everywhere else was fime, Deccan was not going to do the K Pg on its own.
I see you found the paper on the Tanis site from your other comment 🙂
Yes, Chad, of course I know Tanis. It proves that the meteorite impact gave them the final blow, here by flash flood or tsunami. Single families had been dying out before the event.
Most species start dying out when their food source changes or disappears, that’s to say with changing climate.
It doesn’t help that meteorite fans now start to make the meteorite impact solely responsable for the extinction of dinosaurs. There must have been s.th. else, s.th. genetic as the mososaur died out, his main enemy, the shark, survived though.
The air pressure was going down – that might be a reason. The air pressure is supposed to have been 4-5 times and more our values today while they were roaming the Earth.
Up to now it is not even completely clear from which side the meteorite came in and at which angle. The larger ones (every 250-750 million years, estimated) are thought to come in at shallow angles.
The second reason to reject that sort of fear-mongering is the interval for larger ones.
The same has been done with Yellostone. As Yellowstone is not close to any of the large LLSVP Tuzo and Jason it might not have a mantle plume underneath, contrary to Hawai’i and Iceland which doesn’t say that it doesn’t have a shallower magma reservoir. Anyway, fear-mongering with Yellowstone or Campi Flegrei, meteorites and other things. The fashion of fear-mongering for know-nothings with an internet-connection is medieval. It’s like showing the devil and talking the devil like Jesper again – “we’d be plasma”. Yes, well, I can snap dryly, we also have blood-plasma.
You know, Chad, sometimes kids might somehow pop in here, volcanoes-nice. I reject that sort of unscientific fear-mongering. I would call it “graphic content” at least for some groups of people, also from some corners of the world where education is undervalued.
Sorry.
I would argue anyone who finds this place would be no stranger to the sometimes graphic nature, volcanoes are natural disasters after all. There are people who chase tornadoes, who fly in thunderstorms, there is the whole phenomenon of surfing which is in a way no different.
I also encourage you to read some of the articles Carl has written in the past. Is a stretch to call it NSFW but if talking about dinosaurs going extinct is too far then some of these articles might get Carl sent to the dungeon 🙂
I need not speak about the articles Tallis writes…
Point is this entire hobby comes with a certain degree of disaster sensationalism, singling me and Jesper out for our youthful exitement is a tad unfair maybe.
Chad, it is not about the content in general or dinosaurs dying out, and you possibly know it. It is about blowing something up or talking of plasma.
That film i.e. uses the geography of today. Well, the maps differ a bit. The bay in general was much larger. Tethys was probably running through there in a width of around 30° latitude, maybe a little less. The Western Interior Seaway was barely closed.
Florida and other southern states like Texas, Missouri, Mississippi, Alabama, Louisiana and Georgia weren’t there.
South America and North America were probably still separated.
So, we might have a meteorite impact at a shallow angle ending up in an ocean leading to a tsunami, creating havoc, but not like in that stupid film, and a dying species died out, in America of course right away, in other parts of the world possibly later, helped by the Deccan Traps.
I wouldn’t ask Carl to take the film out as I am about the opposite of a friend of censorship.
He knows Jesper, so if he sees this at all he can tell him to drop his plasma talk.
And, btw. the film scared me. I hate being scared an d have to read some science to work against it. And I am still furious in the morning after a good sleep which is rare.
Volcanoes, Chad, are not phantasies, but real dangers, mostly for the locals. VEI 6-7 is rare.
Another thing, Chad: With a No-Fly-Zone like the Ukraine buddy was dreaming of we might have gone down here, Abert, Carl, me, everybody else and also Jesper – his plasma dream might have come true. You would probably survive, but only as long as China doesn’t chime in and attack Taiwan. Have a nice day and enjoy your life!
I might be a bit sensitive right now. And Chad: I remember the Cold War. It wasn’t always that pretty. We could have gone down. Safe.
People who lived through the cold war see things different from other people. The fear it instilled never completely went away. We write about volcanoes and disasters, but we are careful to keep the disasters in general terms rather than go into graphic detail. That seems right to me. Both denial and sensationalism should be avoided when discussing volcanoes – and similar events such as impacts!
As for the extreme temperatures, I think those refer to the pressure shock. It is very brief and cools down again once the pressure wave has passed.
I agree with you to a point. If you look into the description the guy grabbed 15 sources and, sure, it would need work, as Jesper said, to be more accurate but not really fear-mongering, you see. Sure, they stated that most people would be killed and some would consider that fear mongering, but he did not mention that all life is going to die but rather focused on the human casualties, which is a little bias. Also, bone would melt at 1670 degrees Celsius and that is only if it was turned into ash (I could be wrong, but bone would not instantly vaporize or instantly melt as much as the organic parts will). On that note, he did not state that it was a simulation of the impact 66 mya. This is more of a what-if it happened TODAY and that it was more of a project rather than some Faily-News type mongering where they would state “oh, Yellowstone is gonna kill all life on Earth”. The guy just thought “what if an impact the size of the Chicxulub hit the Earth in the modern times”. Assure you, North America was different back then and that all the pieces are in the different spots. Sure, there would have to be improvements, garenteed, but this is not big-time sensationalist fear mongering as you proposed. Call me crazy, but I just posted it up because I thought it was interesting here. Sorry if it looks like I am a pseudo-science guy.
At ground zero any unlucky human is turned into plasma
20 000 c
The plasma stuff If the fireball plume after the impact .. the Asteorid and perhaps 60 000 km3 of Earths crust became totaly vaporized and ejected above the upper atmosphere
Its all the ejecta and the impact plume that heats up the atmosphere as it falls back on the atmosphere at hypersonic speeds after the impact
It woud be an incredible sight
Trillions of trillions of meteors fills the skies high above making the night – skies glow like a furnace and setting the worlds forests on fire
This is good:
The same study documented that a massive surge of water, triggered by the impact, was the cause for the rapidly deposited drape of sediment that locked the event in time and preserved the only known impact-caused vertebrate mass-death assemblage at the KPg boundary. The densely packed tangle of plants, animals, trees, and asteroid ejecta enabled a unique opportunity to work out the fine details of the KPg event, the biota that succumbed to it, and the environment in which they lived.
“The fossil record is a key to understanding biotic response to global-scale hazards, without which we would be ill-equipped to properly respond or react to modern events,” said DePalma. “This modern utility of the fossil record is highlighted by the fact that we currently appear to be perched at the threshold of another episode of global biotic stress.”
The unique structure and pattern of the growth lines in fossil fish bones from the site, similar to a barcode, showed that all of the examined fish died during the spring-summer growth phase. High-tech isotopic analysis of the growth lines provided independent confirmation of this, showing a yearly oscillation that also terminated during the spring-summer growth.
https://www.fau.edu/newsdesk/articles/dinosaur-extinction-chicxulub-asteroid.php
And this:
The environmental severity of large impacts on Earth is influenced by their impact trajectory. Impact direction and angle to the target plane affect the volume and depth of origin of vaporized target, as well as the trajectories of ejected material.
https://www.nature.com/articles/s41467-020-15269-x?error=cookies_not_supported&code=bc6e6153-1c97-4c8d-8c59-f9018906ad78
This is science, not fear-mongering.
I’m furious about this kind of films made by attention seekers.
What the Chicxulub Impact Flash woud look like from Florida .. and of course way brigther than that .. Any dinosaurs in the Gulf Region became a spam in the can very quickly, the impact flash from Chicxlulub was probaly bright enough to make you blind and allow you to see the light through the dinosaurs bodies
Thanks. Sane.
State of emergency issued in Velas, São Jorge (Azores) due the quake swarm, as a preventive measure.
https://twitter.com/VOSTAZ/status/1506004105067704328
An eruption in the Azores would be timely. There is on average one every twenty years or so there, and it has been that long
The terrfying scale of the Chicxulub Impact in These simulation graphics.. speaks for itself
No, it doesn’t, because it leaves out the tsunami as far as I can see. It is amazing that we talk about a relatively small wave travelling around the world several times, caused by Hunga-Tonga, and it doesn’t occur to you that a huge tsunami abrazed averything form the surface of the Earth unless it was a brillant swimmer, used to some depth, or could fly high up into the mountains or lived there anyway like some rodents.
Edited. Be nice.. – admin
Chicxulub hit a shallow ocean so the tsunami woud not be more than 300 m I think still enormous compared to anything historical We humans see.
But its possible that the immense force of the impact forced away the ocean so much that it formed kilometers high waves anyway?
Had it hit the deep ocean .. we woud have gotten 5 kilometers high wave sourge possible
We are still talking about flooded coasts and forests flattened by wave sourge
The magnitude 12 X quakes May have stewed up numerous tsunamis
Air shockwave from the impact must have dwarfed the Tonga blast for soure
I remember simulations that indicated impacts tsunamis would not be as large as one might expect. The hole it punches in the sea is too big: it takes a long time to refill and so you don’t get this instant reverse shock, but a drawn out series of turbulent waves. I haven’t kept up with this research. The air pressure wave can itself induce tsunamis, but it travel faster than the ocean wave so you don’t get this resonance build-up. It could still be very large, but not Hollywood size. Earthquakes can generate tsunamis via a resonance in lakes, but more dangerous are the landslides into such lakes.
The tsunami is invisible on these scales in the simulation.. look at the scale bars
The sea is just a thin thin film on these scales even if it was 100 s of meters deep
The Guardian has an article about the Azores swarm. They describe the island itself as a fissure and it is shaped like a fissure.
https://www.theguardian.com/world/2022/mar/21/more-than-1000-earthquakes-shake-portugals-azores-islands
The Japanese website of the Hydrographic and Oceanographic Department of the Japan Coast Guard has recently published new pictures of Nishinonima (March 15, 2022):
More pictures can be found here:
https://www1.kaiho.mlit.go.jp/GIJUTSUKOKUSAI/kaiikiDB/kaiyo18-2.htm
No new eruption, but nice pictures of the island…
Sorry, that was supposed to say Nishinoshima, of course…
Wow that last eruption really destroyed the cone. Went from being a lava shield to full fire fountain vent. I think that big surge in the intensity of the eruption was when the composition of the lava went from being hot and mostly degassed andesite to basalt, from the deep source, fluid but full of volatiles Turned full Etna mode, and then water got into the vent near the end.
With the andesite apparently flushed out there probably wont be another large eruption for a while but it might erupt with small eruptions more often, become the Stromboli of the Pacific.
My, how the boy has grown.
Interesting pattern on the drum from Ruapehu. From GNS Science:
“We consider there is an increased likelihood of eruptive activity as strong tremor is indicating increased gas flux through the system. Despite an increase in gas flow, the lake temperature is only responding slowly, suggesting a partial blockage may exist in the vent beneath the lake. This could allow pressure to build up within the volcano.”
Ooo…er. Don’t like the look of that. Thanks for noting it!
Those are some impressive-looking LP earthquakes and tremor. Thanks for sharing, you don’t see something like this every day.
The Municipal Emergency Plans of the two municipalities of the Island, Velas and Calheta, were activated.
From the beginning of the crisis until 19:00 on 21/03/22, 1329 earthquakes had been registered (CIVISA), 73 senses.
image Ivar/CIVISA.
https://twitter.com/VOSTAZ/status/1506061317706297350
I’m guessing we are looking at a major dike intrusion propagating along the island.
Sao Jorge has an amazing shape. Like a really long fissure swarm. It is normal for volcanic islands to be elongated along its fissure swarms, but Sao Jorge is the most extreme case I know of.
Although I had barely known anything about this volcano before, but it apparently has an interesting history. It often erupts underwater which is good, however it also produced two destructive subaerial eruptions in 1580 and 1808 which had pyroclastic flows. It was one the first instances in which they were described, and apparently the term nuee ardente had its origins in Sao Jorge before being translated to French and used for Mount Pelée.
Thank you my friend. Now authorities of CIVISA assume this swarm is not only tectonic, it’s volcanic too. That’s why they activate the emergency plans.