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Only from its dimensions is historic. It is among the 25 largest on the planet found
the topography map of the rock under the ice sheet and land free of ice around the krater impact / The Natural History Museum of Denmark
In 2015, the University of ġeoċemista & # 39; Copenhagen, Kurt Kjær, noticed a strange depression under the Glacier of Hiawatha & # 39; Greenland. A study now shows that what was found was just the impact of krater & # 39; more than 30 kilometers wide & # 39 ;. Its origin: an asteroid.
Only its dimensions from the crater is already historic, which is one of the largest found in the World 25. However, the history and origin is what really loves science. When and how did a tremendous impact on the continental ice sheet in Greenland?
It turns out that not long ago, not least in & # 39; terms of the history of our planet since at least one kilometer wide meteorite & # 39; its creator.
extraordinary evidence
As explained Kjær: extraordinary discoveries require extraordinary evidence. We have over a decade & # 39; data & # 39; Radar surveys, technical-looking snow which build the topographical map on the glacier. Just as in 2015 we saw a large circular depression under layer. We immediately found that it was something special, but at the same time it was clear it would be difficult to confirm the origin of depression.
further studies
Since then, the last three years have been working and studying area, taking pictures and using new radar developed by the University & # 39; Kansas.
You & # 39; see at the end rounded structure of the ice sheet, especially when flying high enough. For the most part, the krater not be seen through the window of the plane. It is humorous that & # 39; now nobody thought: "Hey, x & # 39; is that semicircular feature there?" From plan is subtle and difficult to see, unless you already know that there.
Using & # 39; satellite imagery taken as & # 39; & # 39 low angle; sun increases the hills and valleys in the terrain of the ice sheet, you & # 39; actually see the whole circle krater in & # 39; these pictures.
Kjær also explained that foreign fakkreth from the beginning to the meteor of & # 39; Cape York escaped in Greenland about 10,000 years ago, the same one that left large chunks & # 39; iron scattered in the same region as glaċer, can & # 39; a link to it? event & # 39; impact?
The recently published work with jikkonvinċiex this is the case, but they present several lines & # 39; convincing evidence to suggest that the krater probably formed over the past 100,000 years.
The geochemical analysis of sediments near the glacier also showed evidence of & # 39; & # 39 processes; impact, indicating the presence of iron. These included quartz, normally found in & # 39; & # 39 areas, impact, and glass, which is created by silica in the bottom with intense heat & # 39; impact.
F & # 39; terms & # 39; age, the researchers believe that they provide evidence b & # 39; healthy enough to think that happened before the Greenland ice covered herself.
It's hard to be wrong to think that the range covers 3 million years ago to 12 years ago only just, at the end of the last ice age. According Kjær: I think it happened when Greenland was covered by ice and therefore a significant amount of molten & # 39; water soluble. This melt water runs to the south at a sensitive point in the climate system.
must know the exact date & # 39; impact
However, currently trying to dig the snow to get foundation samples can be used for data and the exact date of impact.
large hood as the window opened to science. His study raises all kinds & # 39; question, such as the possibility of & # 39; rain & # 39; asteroids or the fact that the impact caused global event & # 39; Cooling can & # 39; very ancient affect human populations.
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