It is an unstable rock, green in color, more than 4 cm from its longest size. And yet this little piece of sandstone still has traces of our future.
It is restored in the mud deep in the ocean, far off the coast of modern-day West Antarctica.
Scientists who found it say it really shouldn’t have been there.
This is what is called a dripper, a piece of ice. It scraped the White Continent with ice.
After being packed out of Antarctica by ice flow, the iceberg was exported and dumped offshore.
What is particularly remarkable about this mosaic is that researchers can tell where it came from.
Using state-of-the-art “geographic fingerprinting” techniques, they confidently confirmed that it came from the Elsworth Mountains, about 1,300 km from where the rock was removed from the Amundsen Sea by a drilling rig.
The mystery is that the Elsworths, Antarctica’s highest mountain range, are located on the outskirts of the continent, and such a rock is unlikely to survive until now.
“Considering this material, it will not withstand a large amount of transport, with” then “transformation by several steps of the cycle. And, moreover, it probably will not last very well. “The interaction between the ice caps will be broken,” Christine Sidway, a professor of geology at Colorado College in the United States, told BBC News.
So how did he travel so far? The answer lies in the age of deposits collected in 2019 by the International Ocean Detection Program (IODP) “Campaign 379”.
In the geologists’ schedule, they are the middle of the Pliocene. That is about three million years ago.
The middle of the Pliocene is a fascinating period in the history of the Earth due to its strong reactions today. This was the last time the atmosphere had the same concentration of carbon dioxide in the greenhouse gas – more than 400 million parts.
At that time the temperature was significantly warmer, maybe 2-3 degrees in the world, and the sea level was even higher, possibly 10-20 meters above the surface of the modern ocean.
And this is where our little green sandstone rock comes into play.
The middle levels of the Pliocene Sea suggest that the West Antarctic ice sheet, or at least significant parts of it, had melted; there was a large open sea route in its place.
It is difficult to imagine when you look at the maps of Antarctica today. we see its ice cover as a continuous solid mass. But take out the ice, և you are left with a large archipelago, a number of large islands.
It explains how the tile still travels.
The ice of the Elsworth Glacier took it, then placed it on an iceberg to swim more than a thousand miles on the high seas and land on the site that eventually restored the 379th Expedition.
“Our findings confirm that ice can disappear fairly quickly, and that it can recover quite easily,” he said.
“We read from very detailed notes that we are trying to make it even more detailed that the ice has collapsed significantly, particularly in the Middle Pliocene.
“This is a break if we read the current literature by climate designers that we can access … The Pliocene climate is what we expect to enter. And if the warm-up continues at the current rate, we can stay there. “
No one expects the West Antarctic ice sheet to collapse any time soon, but the tiny sandstone is a warning to scientists about the conditions we can eventually recreate if we do not find ourselves in a climate crisis soon.
Professor Sidway presented the details of the IODP Expedition 379 study to the General Assembly of the European Geological Survey (EGU) this week. The #vEGU21, usually held in Vienna, Austria, was added online this year due to Covid restrictions.