Since 2015, when researchers at the GLOBE Institute at the University of Copenhagen discovered the Shivata impact crater in northwestern Greenland, uncertainty about the age of the crater has been the subject of considerable speculation. Could the asteroid have crashed into Earth 13,000 years ago, when humans were already living on Earth? Will its impact catalyze a nearly 1,000-year global cooling period known as the Young Drought?
New analyses of sand and rocks from the Danish Natural History Museum and the GLOBE Institute at the University of Copenhagen, as well as the Swedish Natural History Museum in Stockholm, show that the answer is no. The History of the Haysaw Impact Crater is much longer. In fact, a new study published in Science Advances says it is 58 million years old.
"Measuring craters has always been a particularly difficult problem, so it is very gratifying that two laboratories in Denmark and Sweden have reached the same conclusion using different calculation methods. So I'm sure we've determined the actual age of the crater, which is much older than many people once thought," says Michael Storey of the Danish Museum of Natural History.
"Determining the new age of the crater surprises us all," says Gavin Kenny of the Swedish Museum of Natural History, "and in the future, it will help us investigate the possible impact of the impact on the climate of an important era in Earth's history." ”
As one of those who helped discover the Haysaw impact crater in 2015, Professor Nicolaj Krog Larsen of the GLOBE Institute at the University of Copenhagen was pleased that the exact age of the crater was confirmed.
"It's amazing to know its age now. Ever since we discovered the crater seven years ago, we've been working hard to find a way to determine its age. Since then, we have conducted several field trips to the area to collect samples related to the Haywar impact," said Professor Larsen.
Age is revealed through laser beams and sand grains
When the Asteroid Haysaw hit the Earth's surface, northwestern Greenland was not covered in a kilometer-thick layer of ice, releasing millions of times more energy than an atomic bomb. At the time, the Arctic was covered in temperate rainforest and wildlife abounded – temperatures of 20 degrees Celsius were the norm. Eight million years ago, a larger asteroid struck what is now Mexico and caused the extinction of dinosaurs on Earth.
The asteroid slammed into Earth and left a crater thirty-one kilometers wide and one kilometer deep. This crater is large enough to hold the entire washington, D.C. Today, the crater is located under the Haysaw Glacier in northwestern Greenland. Rivers flowing out of glaciers provided researchers with sand and rock that were overheated by impact 58 million years ago.
The sand was analyzed at the Danish Museum of Natural History, using a laser to heat the grains of sand until they released argon, while the rock samples were analyzed at the Swedish Museum of Natural History using uranium-lead determination of the mineral zircon.
There is still a lack of clear evidence that the Haysaw impact disrupted the global climate. However, the dating of the crater allowed the international team of researchers studying the crater to begin testing various hypotheses to better understand its impact on the local and global climate.