Ice blocks have left grooves at the bottom of the North Sea, and may today be useful for unraveling secrets from the coldest regions on Earth.
When the ice layers that covered much of northern Europe were quickly retreating, about 18,000 or 20,000 years ago, the North Sea, between England, Norway and Denmark, had unexpected visitors: colossal iceberments.
These blocks of ice had the size of cities and eventually left a mark to this day at the bottom of the North Sea.
“We can estimate, based on the extent of the excavations and what is known about the old levels of the sea, that these iceberments probably had five to a few dozens of kilometers wide and perhaps a few hundred meters thick – iceberries on the scale of a medium -sized British city,” researcher James Kirkham.
In the North Sea, the straight lines of the large icebergos are replaced by irregular depressions made by the narrow keys of much smaller ice blocks, explain the authors of the published in Nature This Thursday. In the background, there is a “change of regime” in which large iceberments are replaced by numerous small iceberments.
A Radiocarbon dating from sediments It shows that this change occurred within 20,000 to 18,000 years ago.
This investigation now launches new doubts: the birth of mega -bergs like the A23A and the A68a can announce the widespread collapse from Antarctica’s ice platforms?
“James’s investigation underlines mine, which mentions the fact that the major delivery events are not necessarily a sign of instability or alarm reason,” says scientist Emma Mackie, not involved in the study. “InsteadIce platforms disintegrate through death for a thousand cuts. We must worry when we stop seeing the big events of delivery. ”
