LAVRENCE – An ice survey in Greenland has revealed evidence suggesting that one kilometer of iron asteroid hit the island about 12,000 years ago at the end of the Pleistocene. The final 30-kilometer crater remained hidden under half a mile of thick ice sheets. Recently he was subjected to research into the ultra-wide radar cirrus system developed at CRSSIS at the University of Kansas.
An influential crater under the Hiavath glacier in the far northwestern part of Greenland is detailed in a new article by Science Advances.
It is identified by data collected from 1997 to 2014 by the Canadian University for NASA Arctic Regional Climate Review and Operation IceBridge program and supplemented with additional data collected in May 2016 using a multi-purpose coherent remote radar (MCoRDS) developed by the KU.
"Over the past few decades, we have received a lot of radar data, and glaciologists have put this data on radar data to create Greenland iceberg maps," said co-author John Paden, associate professor of electrical engineering and computer science at the KSU and researcher CReSIS. "The Danish scientists looked at the map and saw this huge dump crater under the ice sheet and looked at satellite images and – because the crater on the edge of the ice sheet – you can see a circular pattern." The combination of these two things has strongly shown that it is a crater. Based on this discovery, a detailed radar survey was conducted in May 2016 using the latest state-of-the-art radar designed and built by the KU for the Alfred Vegener Institute in Germany. "
Paden, who helped develop the MCoRDS radar signal processing software, took part in low-level flights in the network template above the crash crater, in order to review the dimensions in more detail.
"You can see a hardened construction on the edge of the ice sheet, especially when you fly high," he said. "Most of the crater is not visible from the airplane window, and it's ridiculous that nobody ever thought:" Hey, what's a semicircular plan? "It's hard to see on a plane if you do not know it's there." When the sun was a bit above the horizon, emphasizing the hills and valleys on the ice-field, you can see the circle of the crater in these pictures. "
In order to confirm satellites and radar findings, the research team carried out subsequent field studies on glaciophluvial sediment from the largest river that controls the crater. This highlighted the presence of "the influence of quartz and other grain impacts", which include glass. The research team believes that these walls and glass grains probably formed in collision with the deposition of grains in the meta sedimentary bed.
It is still necessary to determine the time of the fall of the asteroid on Greenland. The authors write that the evidence "suggests that the crater Hijavath was created during the Pleistocene, because this age is largely in line with the conclusions from the current available data." However, this wide time interval remains "uncertain". In the southwestern crater, he found a region rich in possible fragments created during the fall, which could help narrow the time span.
"In the atmosphere, there would be dirt that would affect the climate, and it could float a lot of ice, so a sudden flood of fresh water could come to Nares' crossing between Canada and Greenland, which would affect the flow of oceans across the region," he said. Fallen. "Evidence suggests that the impact is likely to occur after the Greenland ice sheet has been created, but the research team is still working on a precise approach."
Credit: University of Kansas
Other KU members who participated in the research who discovered the impact of the crater include Rick Hale, Chairman of Air Engineering and Assistant Director of CReSIS; Carla Leuschena, professor of electrical engineering and informatics and director of CReSIS, and Fernando Rodriguez-Morales, professor of electrical engineering and computing. KU researchers worked closely with colleagues at the University of Copenhagen and the Alfred Vegener Institute in Germany.
Paden says that for three years between the discovery of the crater and the discovery of this discovery, it was a pleasure and exciting to be part of an exclusive group of scientists who knew great influence.
"It was really cool – it was the thing I told the kids when I came home," Paden said. "I said," Look at this, this is under the ice. "It was one of those fun moments, they were astonished, many times, my research was not interesting to them, but this crater of influence was something that caught them."