Giant impact crater in Greenland occurred a few million years after dinosaurs went extinct

The researchers have dated the crater, which is 31 km wide and buried under a kilometer of ice. The dating ends speculation that the meteorite impacted after the appearance of humans and opens up a new understanding of Earth's evolution in the post-dinosaur era.

Uncertainty about the age of the Hiawatha impact crater has been the subject of considerable speculation since 2015, when researchers discovered it. It is possible that the asteroid slammed into Earth as recently as 13,000 years ago. The Younger Dryas are a nearly 1,000-year period of global cooling.

The answer is no, according to new analyses performed on grains of sand and rocks from the Hiawatha impact crater by the GLOBE Institute at the University of Copenhagen and the Swedish Museum of Natural History. A new study published in the journal Science Advances says it is 58 million years old.

Dating the crater has been a particularly tough nut to crack, so it is gratifying that two laboratories in Sweden andDenmark used different dating methods to arrive at the same conclusion. According to Michael Storey of the Natural History Museum of Denmark, the crater is much older than people think.

The new age of the crater surprised us all. In the future, it will help us investigate the impact of climate change during an important period of Earth's history.

The exact age of the Hiawatha impact crater has now been confirmed, thanks to Professor Nicolaj Krog Larsen of the GLOBE Institute at the University of Copenhagen.

It is great to know its age. We have been trying to find a way to date the crater since we discovered it seven years ago. Since then, we have been on several field trips to the area to collect samples.

Laser beams show the age of the sand.

The asteroid hit the Earth's surface with more energy than an atomic bomb. The temperature in the north was 20 degrees Celsius and the rainforest was covered with plants. The extinction of Earth's dinosaurs was caused by an even larger asteroid hitting Mexico.

A thirty-one-kilometer-wide, one-kilometer-deep crater was created when the asteroid smashed into Earth. The crater is large enough to hold the entire city of Washington D.C. Sand and rocks that were superheated by the impact 58 million years ago were supplied by the rivers flowing from the glacier.

The sand was analyzed at the Natural History Museum ofDenmark by heating the grains with a laser until they released argon gas, whereas the rock samples were analyzed at the Swedish Museum of Natural History.

There is no evidence that the Hiawatha impact disrupted global climate. The dating of the crater allows the international research team to begin testing hypotheses to better understand what impact the crater had on both the local and global climate.

More information: Gavin G. Kenny et al, A Late Paleocene age for Greenland's Hiawatha impact structure, Science Advances (2022). DOI: 10.1126/sciadv.abm2434 Journal information: Science Advances Citation: Giant impact crater in Greenland occurred a few million years after dinosaurs went extinct (2022, March 9) retrieved 9 March 2022 from https://phys.org/news/2022-03-giant-impact-crater-greenland-million.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.