The origin of the Patomskiy crater

 

 

Scientists reconstruct asteroid impact SIX TIMES bigger than the blast that wiped out the dinosaurs and say it boiled oceans, burned the sky, and shook the Earth for thirty minutes 36 mile wide asteroid is believed to have hit Earth 3.26 billion years ago Collision punched a crater into the planet’s crust 300 miles across Atmosphere filled with dust and the tops of oceans boiled Scientists have reconstructed one of the biggest asteroid impacts ever to hit Earth - and say it was six times as big as the blast than wiped out the dinosaurs. The 36 mile wide asteroid is believed to have hit Earth 3.26 billion years ago, creating unique geological features found in a South African region known as the Barberton greenstone belt. Researcher say the impact would have boiled oceans, burned the sky, and cause the planet to shake for 30 minutes. +2 The massive asteroid was almost as wide as Rhode Island and about three to five times larger than the rock thought to have wiped out the dinosaurs. HOW BIG WAS IT? The huge impactor – between 37 and 58 kilometers (23 to 36 miles) wide – collided with the planet at 20 kilometers per second (12 miles per second). The jolt, bigger than a 10.8 magnitude earthquake, propelled seismic waves hundreds of kilometers through the Earth, breaking rocks and setting off other large earthquakes. Tsunamis thousands of meters deep – far bigger than recent tsunamis generated by earthquakes — swept across the oceans that covered most of the Earth at that time. The collision punched a crater into the planet’s crust that’s nearly 500 kilometers (about 300 miles) across: greater than the distance from Washington, D.C. to New York City, and up to two and a half times larger in diameter than the hole formed by the dinosaur-killing asteroid. Seismic waves bigger than any recorded earthquakes shake the planet for about half an hour at any one location – about six times longer than the huge earthquake that struck Japan three years ago. The impact also sets off tsunamis many times deeper than the one that followed the Japanese quake. Although scientists had previously hypothesized enormous ancient impacts, much greater than the one that may have eliminated the dinosaurs 65 million years ago, now a new study reveals the power and scale of a cataclysmic event some 3.26 billion years ago which is thought to have created geological features found in a South African region known as the Barberton greenstone belt. The research has been accepted for publication in Geochemistry, Geophysics, Geosystems, a journal of the American Geophysical Union. The collision punches a crater into the planet¿s crust that¿s nearly 500 kilometers (about 300 miles) across: greater than the distance from Washington, D.C. to New York City, and up to two and a half times larger in diameter than the hole formed by the dinosaur-killing asteroid. WHAT HAPPENED TO EARTH? The sky would have become red hot, the atmosphere would have been filled with dust and the tops of oceans would have boiled, the researchers said. The impact sent vaporized rock into the atmosphere, which encircled the globe and condensed into liquid droplets before solidifying and falling to the surface, according to the researchers. Tsunamis thousands of meters deep – far bigger than recent tsunamis generated by earthquakes — swept across the oceans that covered most of the Earth at that time. The huge impactor – between 37 and 58 kilometers (23 to 36 miles) wide – collided with the planet at 20 kilometers per second (12 miles per second). The jolt, bigger than a 10.8 magnitude earthquake, propelled seismic waves hundreds of kilometers through the Earth, breaking rocks and setting off other large earthquakes. Tsunamis thousands of meters deep – far bigger than recent tsunamis generated by earthquakes — swept across the oceans that covered most of the Earth at that time. 'We knew it was big, but we didn’t know how big,' Donald Lowe, a geologist at Stanford University and a co-author of the study, said of the asteroid. Lowe, who discovered telltale rock formations in the Barberton greenstone a decade ago, thought their structure smacked of an asteroid impact. The new research models for the first time how big the asteroid was and the effect it had on the planet, including the possible initiation of a more modern plate tectonic system that is seen in the region, according to Lowe. The study marks the first time scientists have mapped in this way an impact that occurred more than 3 billion years ago, Lowe added, and is likely one of the first times anyone has modeled any impact that occurred during this period of the Earth’s evolution. The impact would have been catastrophic to the surface environment. The smaller, dino-killing asteroid crash is estimated to have released more than a billion times more energy than the bombs that destroyed Hiroshima and Nagasaki. The more ancient hit now coming to light would have released much more energy, experts said. +2 Although scientists had previously hypothesized enormous ancient impacts, much greater than the one that may have eliminated the dinosaurs 65 million years ago, researchers have now modelled the power and scale of the cataclysmic event for the first time The crator covers an areas 500km wide The impact may have been one of dozens of huge asteroids that scientists think hit the Earth during the tail end of the Late Heavy Bombardment period, a major period of impacts that occurred early in the Earth’s history – around 3 billion to 4 billion years ago. The study’s co-authors think the asteroid hit the Earth thousands of kilometers away from the Barberton Greenstone Belt, although they can’t pinpoint the exact location. 'We can’t go to the impact sites. In order to better understand how big it was and its effect we need studies like this,' said Lowe. The study’s findings have important implications for understanding the early Earth and how the planet formed. The impact may have disrupted the Earth’s crust and the tectonic regime that characterized the early planet, leading to the start of a more modern plate tectonic system, according to the paper’s co-authors. HOW THEY DID IT The pummeling the planet endured was 'much larger than any ordinary earthquake,' said Norman Sleep, a physicist at Stanford University and co-author of the study. He used physics, models, and knowledge about the formations in the Barberton greenstone belt, other earthquakes and other asteroid impact sites on the Earth and the moon to calculate the strength and duration of the shaking that the asteroid produced. Using this information, Sleep recreated how waves traveled from the impact site to the Barberton greenstone belt and caused the geological formations. The geological evidence found in the Barberton that the paper investigates indicates that the asteroid was “far larger than anything in the last billion years,' said Jay Melosh, a professor at Purdue University in West Lafayette, Indiana, who was not involved in the research. The Barberton greenstone belt is an area 100 kilometers (62 miles) long and 60 kilometers (37 miles) wide that sits east of Johannesburg near the border with Swaziland. It contains some of the oldest rocks on the planet. The model provides evidence for the rock formations and crustal fractures that scientists have discovered in the Barberton greenstone belt, said Frank Kyte, a geologist at UCLA who was not involved in the study. 'This is providing significant support for the idea that the impact may have been responsible for this major shift in tectonics,' he said.

When one geologist stumbled across a massive mound 65 years ago, he had no idea his discovery would spark one of the world’s strangest scientific mysteries. The site in Irkutsk, Siberia was discovered in 1949 and is a huge convex cone with a funnel-shaped recess and a rounded hill in the middle, which looks a little like an eagle’s nest with an egg nestled inside it. The origin of the Patomskiy crater has baffled scientists for decades and theories for its existence have ranged from a nuclear blast to a secret gulag mine and even a meteorite strike. The site in Irkutsk, Siberia was discovered in 1949 and is a huge convex cone with a funnel-shaped recess and a rounded hill in the middle, which looks a little like an eagle's nest with an egg nestled inside it THE PATOMSKIY CRATER The mysterious crater - also known as the 'eagle's nest' - was discovered 65 years ago in Irkutsk, Siberia, by a Russian geologist. The cone is 80 metres tall from the lowest point of its base and measures 150 metres wide. It is thought to be just 250 years old, although estimates differ widely. Scientists previously suggested it was a slagheap, but now think there were not enough people living in the area to create it. Some people believe it was made by aliens. Scientists threw out the idea that the mound was made as the result of a uranium ore explosion as the site has low background radiation. They have floated the idea that it could have been made by a volcano, but none have been found nearby. An impact made by a meteorite is the favourite theory but no evidence of fragments has been found. It is thought there is something with a high iron content over 100metres below the crater, which could be a meteorite. The crater is 'alive' and changes shape - by rising and falling - constantly. Trees nearby the site are reported to grow abnormally fast. The current thinking is that the site was indeed created by a meteorite strike, but no evidence has been found to support the theory. The cone is 80metres tall and has a diameter of 150metres at its widest. The depth of the inner circle ditch is around 10metres.  It was named Patomskiy after a nearby river and was discovered by a geologist called Vadim Kolpakov who tried and failed to arrange a scientific trip to examine the site, but numerous expeditions have taken place since and one last year collected samples. Theories that the mound is a giant slagheap have been thrown out as there were not enough people living nearby when the crater is thought to have formed to create such a pile.  And there were never labour camps or gulags in the region. Half a tonne of samples were taken from the site and removed by helicopter last year. The samples led scientists to dismiss ideas of a uranium ore explosion as the background radiation at the site is low and no uranium has been found nearby either. This left them with two main theories – one of a volcano and another of a meteorite.  However, the mysterious site has not given up any meteoritic material and the area is not thought to be volcanic. In fact there are no volcanoes within thousands of kilometres of the Patomskiy crater and it also seems to be relatively new. The origin of the Patomsky crater has baffled scientists for decades and theories for its existence have ranged from a nuclear bomb blast, a secret Gulag mine and meteorite strike The cone is 80metres tall and has a diameter of 150metres at its widest. The depth of the inner circle ditch is around 10metres. Scientists thought the crater was only between 100 and 500 years old and could be the result of the Tunguska meteorite, which fell in the Krasnoyarsk region in 1908, but whose crater has never been discovered. It is thought the meteorite was sighted just 70km away from the ‘eagle’s nest’ and that distance is a mere 10 to 15 seconds of flight. As the Tunguska event occurred in 1908, the age coincides, but modern tests have shown that the crater is actually 250 years old – so it could have been formed by a previous meteorite that fell when the area was virtually unpopulated. The strange mound was found in Irkutsk, Siberia (pictured) was discovered in 1949 but it was only last year that scientists took samples from the site The crater was named Patomsky after a nearby river and was discovered in Siberia (pictured) by a geologist called Vadim Kolpakov who tried and failed to arrange a scientific trip to examine the site. The first expedition only took place last year Scientists now think that there is something with a high iron content and ferromagnetic materials buried between 100 and 150 metres underneath the crater. They believe it could be a meteorite or another incredibly dense object, but they are not certain. The fact that the crater is ‘alive’ as its shape changes constantly - by rising and falling - and that the trees nearby the site are reported to grow abnormally fast, adds to the mystery. Scientists now think that there is something with a high iron content and ferromagnetic materials buried some 100 to 150 metres underneath the crater (pictured)