A team of scientists has recently discovered a giant impact crater, larger than the surface of Paris, which had remained hidden under a thick layer of ice in northern Greenland, and was formed by the impact of an iron meteorite.
This iron meteorite is believed to be responsible for causing the mysterious, 1,000-year period known as Younger Dryas. The Younger Dryas (c. 12,900 to c. 11,700 years BP) was a return to glacial conditions which temporarily reversed the gradual climatic warming after the Last Glacial Maximum started receding around 20,000 BP.
Its diameter of more than 31 kilometers places it among the 25 largest impact craters on Earth, according to the findings of an international team of researchers from Denmark, Germany, and the United States.
The study detailing the discovery was published in the journal Science Advances.
Scientists believe that the crater was formed when a one-kilometer-wide iron meteorite crashed in northern Greenland about 12,000 years ago, towards the end of the last ice age – although more studies are needed to pinpoint the date.
It is believed that the impact of the iron meteor threw debris several hundred miles in every direction, and some fragments may have traveled as far as modern-day Canada.
Since then the massive crater had remained buried under the ice of the Hiawatha glacier.
The 12-billion-tonne meteor impacted the Earth’s surface with the power of 47 million Hiroshima bombs, obliterating all life within a 60-mile (100 km) radius, scientists explained.
“We’ve collected lots of radar-sounding data over the last couple of decades. Glaciologists put these radar-sounding datasets together to produce maps of what Greenland is like underneath the ice,” explained Study co-author Dr. John Paden.
“Danish researchers were looking at the map and saw this big, crater-like depression under the ice sheet and looked at satellite imagery and – because the crater is on edge of the ice sheet – you can see a circular pattern there as well. The two combined made a really strong case for this being an impact-crater site,” he added.
The impact crater was firmed discovered in July of 2015 when experts from the Natural History Museum of Denmark, University of Copenhagen spotted a depression located beneath the glacier, while they were creating a map of the glacier’s physical features.