West Antarctic's Thwaites Glacier—an enormous ice mass with the potential to trigger catastrophic sea level rise—could retreat far more quickly in the coming years than scientists previously anticipated. It is roughly the size of the U.S. state of Florida and, if melting continues at the current pace, it could raise global sea levels by 11 feet or more.
A team of scientists led by Alastair Graham of the University of South Florida's College of Marine Science observed the sea floor in front of Thwaites using a sensor-equipped autonomous submarine. Findings over two extended survey missions raises the potential upper 'speed limit' for Thwaites behavior in the near future.
A new study published in Nature Geoscience reveals
"Over a duration of 5.5 months, Thwaites' grounding zone retreated at a rate of >2.1 km per year—twice the rate observed by satellite at the fastest retreating part of the grounding zone between 2011 and 2019," the analysis notes. "Similar rapid retreat pulses are likely to occur in the near future when the grounding zone migrates back off stabilizing high points on the sea floor."
Robert Larter, a marine geophysicist with the British Antarctic Survey, said that the research shows Thwaites "is really holding on today by its fingernails, and we should expect to see big changes over small timescales in the future—even from one year to the next—once the glacier retreats beyond a shallow ridge in its bed."
Graham warned that "just a small kick to Thwaites could lead to a big response."
Researchers have cautioned that several feet of global sea level rise could have devastating consequences, displacing tens of millions of people.
Tom Frazer, dean of the University of South Florida's College of Marine Science, said that just because the glacier is "out of sight, we can't have Thwaites out of mind."
Rapidly Retreating Doomsday Glacier Clinging 'By Its Fingernails': Study (commondreams.org)
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