News Picks : Previous Greenland glacial melt may have raised sea level 6 m
Ars Technica: Earth has experienced periodic warming periods during which there was widespread shrinking of glaciers. The warm interglacial period that occurred 400 000 years ago lasted much longer than other such periods and may have raised sea levels 6 to 13 m above current levels. But where that melt came from has been unclear. Alberto Reyes, now of the University of Alberta, and Anders Carlson of Oregon State University and their colleagues suggest that the retreat of Greenland’s glaciers may have been a primary contributor. They examined seafloor cores off Greenland’s coast and looked for silt that was deposited by the motion of the glaciers. Compared with the amount of sediment laid down during the two most recent interglacial periods, there was significantly less silt. This suggests that the glaciers had retreated much more than in the other warm periods and therefore eroded less of the terrain. Through the use of a model that incorporated their findings, Reyes and Carlson showed that the loss of Greenland glacial ice would have raised sea levels 4.5 to 6 m above where they currently are. That could account for the majority of the rise during the period.