A research team led by U.S. and Korean scientists deployed three moorings with hydrophones attached seaward of the Nansen Ice Shelf in Antarctica’s Ross Sea in December of 2015 and were able to record hundreds of short-duration, broadband signals indicating the fracturing of the ice shelf.
The “icequakes” primarily took place between January and March of 2016, with the front of the ice sheet calving into two giant icebergs on April 7.
The day the icebergs drifted away from the shelf coincided with the largest low-pressure storm system the region had recorded in the previous seven months, the researchers say.
Results of the study are being published this week in Frontiers in Earth Science.
SEE ALSO: Geological ‘Hotspot’ Melting Pine Island And Thwaites Glaciers, Not Global Warming
“It appears that while the icebergs had broken free of the main ice sheet, they stayed attached until the combination of high winds and a strong low-pressure storm combined to break them loose,” noted Bob Dziak, a research oceanographer with the National Oceanic and Atmospheric Administration and lead author on the study.
“The processes behind the unpinning and breakup of Antarctic ice shelves is not fully understood, and our study suggests that storms play an under-appreciated role in their breakup,” Dziak said.
Next January, Dziak and researchers from Oregon State University and the Korea Polar Research Institute will return to Antarctica to replace the three hydrophones near Nansen, and deploy addition acoustic sensors near the massive Thwaites Glacier, called one of the most important—and dangerous—glaciers on the planet.
Read rest at Phys.org
“Strong Storms Behind Antarctic Ice Shelf Collapse”
Maybe it was already weakened before the storm…………
https://www.wired.com/story/antarctica-thwaites-glacier-breaking-point/
THE RACE TO UNDERSTAND ANTARCTICA’S MOST TERRIFYING GLACIER
Saving Thwaites, or even finding out whether the Ghost Ridge looks stable, won’t save the world. At the rate temperatures are rising, Anandakrishnan may soon have to pack up his explosives and go elsewhere. By then, some other glacier will be hanging by its fingernails.
I asked Anandakrishnan whether there was any chance that he might crack off part of Thwaites with his explosive charges, which can sometimes add up to about a kilogram. I imagined some kind of calamitous avalanche, as in the Alps. He shook his head. “This ice sheet is so large,” he said.
His small bombs would destroy the office we were sitting in, but they were nothing compared with the forces of nature moving Thwaites’ ice into the ocean… maybe