Unstable foundation didn’t cause Larsen B’s breakdown
Balmy surface temperatures, not an unstable underbelly, probably prompted the largest ice shelf collapse ever recorded, researchers report in the Sept. 12 Science.
In 2002 a Rhode Island–sized hunk of the Larsen B ice shelf on the Antarctic Peninsula shattered into thousands of icebergs during the peninsula’s hottest summer on record (SN: 3/30/02, p. 197). Radar maps at the time suggested that the point where the shelf floated off the seabed, called the grounding line, had retreated farther inland, triggering the overhanging ice to break off. Now seafloor sediments reveal that Larsen B’s grounding line had remained stable for thousands of years before the ice shelf’s collapse.
The finding demonstrates that the grounding line wasn’t involved in Larsen B’s breakup, says study coauthor