It has long been known that something very dramatic happened during the Younger Dryas about 12,000 years ago. This is when a large number of animal and plant species suddenly disappeared. There was also a sudden drop in temperature.
We know that Earth’s climate goes through cycles of about 120,000 years with sharp rises to the temperature followed by a relative slow decline into a minimum. The Younger Dryas event that plunged the world back into an ice age happened during the last sharp temperature rise, and it is suspected that it was this sudden reversal of the ongoing warming that caused the mass extinction.
While the repeated pattern of sharp temperature rises followed by prolonged cooling can be attributed to galactic super-waves, the sudden reversal of temperature changes during the Younger Dryas must have had something else. A meteorite impact has been proposed as a possibility, and it now looks like this hypothesis may be correct.
An enormous impact crater has recently been discovered on Greenland. The crater is 19 miles wide. Its effect can be seen in ice core samples older than 12,000 years, implying that the event happened during the Younger Dryas. The impact crater is so large that its effect must have been felt globally. There must have been earthquakes and tsunamis all over the place, not only in the arctic, but in far away places as well. There may even have been a short lived pole reversal. This in turn may be the source of many legends about extraordinarily large floods, earthquakes and volcanic eruptions.