Saturday , July 2 2022

They discovered an asteroid-producing crater under the ice of Greenland.



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Date only with sizes. It is among the 25 largest on the planet.

They discovered an asteroid-producing crater under the ice of Greenland.

Rocky topography under the ice layer and a groundless map of the crater surrounding the impact crater / Danish Museum of Natural History

In 2015, the geochemist Kurt Kjær of the University of Copenhagen noticed a strange depression under the Greenland Hiawatha Glacier. A study now reveals that what they just found is an impact crater of more than 30 kilometers. Origin: an asteroid.

One of the biggest 25 in history, with only its own size crater. However, history and its origin are what really interests science. When and how did we create a great impact on the continental ice layer in Greenland?

Not long after the meteorite of at least one kilometer, at least not in terms of the history of our planet.

extraordinary evidendias

As Kjær explains: extraordinary discoveries require extraordinary evidence. We have a radar survey of more than a decade, a technique to look into the ice we're mapping the topography on the glacier. In 2015, we found large circular depression beneath this layer. We knew immediately that this was something special, but it was also hard to verify the origin of depression.

sustain

Since then, the last three years, working using a new radar developed by the University of Kansas and working to work the region.

You can see the round structure on the edge of the ice sheet, especially when flying high enough. For the most part, the crater cannot be seen through the aircraft window. No one has ever been surprised: Şimd Hey, what's that semicircular feature out there? Hiç Unless you know you saw it on the plane, it's hard and hard to see.

You can see the entire crater circle on these images using satellite images taken with a low angle of sun, highlighting the hills and valleys in the terrain of the ice sheet.

Kjær also recalled that the stranger may have a link to the meteor of Cape York, which hit him in Greenland 10 thousand years ago, the same thing separating him from the huge iron fragments scattered across the glacier. effect event?

The recent study has not been able to conclude that this is the case, but there are many compelling evidence that the crater has probably occurred over the last 100,000 years.

The geochemical analysis of the sediments near the glacier showed evidence of the impulse processes indicating the presence of iron. These are glass consisting of quartz, which is commonly found in the impact zones, and silica in the main rock in the intense heat.

In terms of age, researchers believe that their evidence is strong enough to think that Greenland was before it covered the ice.

It's hard to be mistaken if the time until 3 million years ago dates back to the end of the last ice age, only 12 thousand years ago. According to Kjær: I think it was when Greenland was covered with ice, so a significant amount of melt would melt water. This melt water goes southward in the climate system towards a sensitive point.

They want to know the exact date of impact

However, they are now trying to pierce the ice, to obtain samples of the bedrock which can be used until the exact date of aging and impact.

The window that he opened for science is as big as a crater. His work raises any questions, such as the possibility of a rainfall of asteroids, or the fact that this effect leads to a global cooling event that can greatly affect people's old populations.

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