Meteorite strikes Greenland with 47 million bombs in Hiroshima

An international research group led by Danish researchers discovered a 31 km wide crater under ice in northern Greenland.

Researchers believe that the giant crater was created by an iron meteorite 12,000 years ago, that is, at the end of the last ice age. The clash has likely had major consequences on the climate and biodiversity of the Earth, and it can not be ruled out that it was important that the ice age ends.

– The meteorite weighed about 12 billion tons and triggered something that corresponds to 47 million times the energy bomb of Hiroshima. A slowdown in this order can certainly change the climate, said Professor Kurt H. Kjær.

He is the principal author of a new study on discovery, published in the journal Science Advances.

– This is an excellent study! Very exciting. I had heard about it before, but it's still better than I thought, "said English geology professor Adrian Jones.

Could have annihilated Paris and London

This is the first time that researchers have found a crater under one of the largest ice caps in the world, and this has only been possible thanks to a revolutionary technology:

By flying over the so-called Hiawatha Glacier by plane and scanning the ice with a powerful radar, the scientists retrieved detailed information about the appearance of the physical structure of the Earth and Ice under the mileage traveled by ice.

In this video, you can see how that happened – with your own video, the video produced by NASA, which also lists researchers in the list of authors of the new study:

Scientists also discovered that the meteorite had to be about 1.2 km in diameter to create a hole of this size.

"It would have been really problematic for humanity if it had happened today, depending on where it happened, it would have destroyed cities like Paris and London. says Adrian Jones, who works at University College London.

The crater is exceptionally well preserved

Scientists know a total of about 180 craters on Earth, but only a few are as big. With its 31 kilometers in diameter and 300 meters deep, it lands in 25th place.

The crater is incredibly well kept.

"The exceptional condition is surprising because the ice eliminates the rough edges of the terrain," says Professor Kurt H. Kjær, who works at the Center for GeoGenetik at the National Museum of Natural History.

The state of conservation suggests to scientists that the crater was created after the ice began to cover Greenland. That is, for up to 3 million years and maybe no more than 12,000 years. This makes it one of the largest created late in the history of the earth.

This is important for several reasons.

Declines may be more common than we thought

Previous studies have shown that major clashes can have significant consequences on the climate and biodiversity of the Earth. For example, it is likely that dinosaurs eradicated by a meteoric slurry 65 million years ago.

If the meteorite that created the crater under the Hiawatha Glacier hit the ground 12,000 years ago, it is quite likely that it could have meaning for the end of the previous Ice Age, Adrian believes Jones.

If the impact, the whole geological glasses, occurred so late, this may indicate that the ground is still hit by dangerous meteorites, adds Nicolaj Krog Larsen, one of the other authors.

"Today, we know about 25-30 accidental craters throughout the history of the world, which indicates that there is no particular probability that it will happen again – but if we find more craters of this type under ice, this may suggest The probability is greater, says Larsen, a researcher at the Geoscience Department of Aarhus University.

Colleague: Get facts on the table

Currently, researchers have not been able to date the crater directly. The radar targets, however, show how ice seems to have been affected by the impact, and it seems that it is closer to 12,000 years than 3 million years ago.

It seems that the ice of the previous ice age is "missing". But this remains very uncertain, stress the researchers.

More accurate dating will require ice cores down to the ground. It's hard and expensive.

However, Jørgen Peder Steffensen, professor of ice and climate at the Niels Bohr Institute at the University of Copenhagen, is the only way to do this. He did not participate in the new study, but knows the data behind it.

"They can use all these indirect measures, but in principle, it's a substitute for" the real stuff, "says Steffensen.

reference:

K. H. Kjær mfl: "A large impact crater under the Hiawatha Glacier in northwestern Greenland", Science Advances (2018), DOI: 10.1126 / sciadv.aar8173

© Videnskab.dk. Translated by Lars Nygaard for research.no.