Sediment core record from remote Siberian lake shows unusually warm Arctic periods coincided with deglaciation of West Antarctica
By Bob Berwyn
SUMMIT COUNTY — Researchers studying sediment cores dating back nearly 3 million years found evidence that the Arctic has experienced several intensely warm climate intervals, and that there may be a link between those periods and episodes of dramatic changes in the West Antarctic ice sheet.
“We found eight warm intervals … the majority relatively early in the Quarternary, when temperatures were 4 to 5 degrees Celsius warmer — as well as wetter — than during normal interglacial periods. They occurred irregularly, not following orbital cycles,” said Professor Martin Melles, of the University of Cologne, one of the lead researchers.
Other lead scientists include Julie Brigham-Grette of the University of Massachusetts Amherst; and Pavel Minyuk of Russia’s North-East Interdisciplinary Scientific Research Institute in Magadan.
“That’s what we know. Then we wanted to know the reasons for that. It can’t be explained by greenhouse gas variations or orbital variations, so we compared the interglacial warm intervals with other records,” said Melles, explaining that the warm intervals seemed to match up well with an Antarctic sediment core showing that the West Antarctic ice sheet disintegrated approximately during these same periods. (more…)