Science

The nails that cling to the Thwaites Glacier appear to be peeling off.

On a research cruise in Antarctica, WHOI postdoctoral scientist Peter Kimball helped use the robotic vehicle Jaguar to map the underside of the ice. But the trip was memorable for more than just their success in a harsh environment: "We were stuck in heavy pack ice for nearly two weeks," recalls Kimball. "We couldn't see any open water around the ship, and the ice was just too thick for the ship to break. While we were stuck, this magnificent minke whale broke through a few centimeters of ice in a small lead and was breathing at the hole, right near our ship, for an entire day."
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On a research cruise in Antarctica, WHOI Postdoctoral Scientist Peter Kimball helped use the Jaguar robotic vehicle to map the underside of the ice.  But the trip was memorable for more than just its success in a hostile environment:

On a research cruise in Antarctica, WHOI Postdoctoral Scientist Peter Kimball helped use the Jaguar robotic vehicle to map the underside of the ice. But the trip was memorable for more than just its success in a hostile environment. We were stuck in a huge amount of ice for almost two weeks, Kimball recalls. We couldn’t see open water around the ship, and the ice was too thick for the ship to break up. While we were trapped, this magnificent minke whale broke through a few inches of ice in a small channel and was breathing in the hole, right next to our boat, for an entire day.

The front of the Thwaites Glacier in the vulnerable section of West Antarctica is very wide (70 miles wide where it meets the ocean) and, in its entirety, it is the size of Florida. The glacier is the most feared as it breaks down quickly and threatens coastal cities around the world. The bottle cork for the entirety of West Antarctica contains ten feet of sea level rise. Sea extent collapse will not add to sea level rise, as it floats. When it collapses, the cork bursts and the land ice is free to slide into the Weddel Sea and Amundsen Sea, raising sea level.

All of the damage to Thwaites’ stability is occurring below the ice. Upwelling of warm ocean water softens and erodes the smooth white underside of the glacier. Upwelling also lifts the ice, where warmer waters can flow up ridges and beyond the ground line, encouraging ice breakdown with faster, more fragmented and fractured flow with the threat of collapse. The water can do that because the ice is no longer anchored in the bedrock.

The ocean in front of the glacier is still quite cold, about 34 to 36 degrees Fahrenheit. That’s above freezing, and if you think back to your ice-filled afternoon cocktail, it’s similar to the temperature of the ocean water gobbled up by the glacier. Sipping your cocktail, you notice that the ice is melting, which is precisely what is happening at the bottom of the vast expanse of sea that is Thwaites Glacier. The glacier alone supports two feet of sea level rise.

Geophysicists were able to map the front of the glacier’s seabed. Like you and me, we have a history and Thwaites too.

A 3D rendered view of depth-coloured multibeam bathymetry (shape of the seafloor), collected by Rán across a ridge of the seafloor, just in front of the Thwaites Ice Shelf.
A 3D rendered view of multibeam bathymetry (shape of the seafloor) colored by depth, collected by Rán across a seafloor ridge just in front of the Thwaites Ice Shelf

A recent study from the University of South Florida:

At some point in the last 200 years, during a period of less than six months, the glacier front lost contact with a seafloor ridge and retreated at a rate of more than 1.3 miles per year (2.1 kilometers per year). year), twice the rate documented using satellites between 2011 and 2019.

“Our results suggest that very rapid retreat pulses have occurred on Thwaites Glacier in the last two centuries, and possibly as recently as the mid-20th century,” Graham said.

“Thwaites is really picking at it by the claws, and we should expect to see big changes on small time scales in the future, even from one year to the next, once the glacier recedes beyond a shallow ridge in its bed,” said the marine geophysicist. and study co-author Robert Larter of the British Antarctic Survey.

Thwaites Tongue is fifty miles wide. You can make a distinction in the tongue depending on its stability and if it is anchored in a ridge. While endangered, the western part of the language is still relatively stable. The eastern side is spewing chunks of ice like there’s no tomorrow, and the eastern side also contains most of the land ice. Sooner rather than later for chaos, in my opinion.

For twenty-two years, a major iceberg named Iceberg B22a it broke away from the Thwaites Tongue in 2001 and became stuck on its front, protecting the remaining ice from the open ocean. The iceberg was fifty-three miles long and forty miles wide. It is also subject to warming waters, and the iceberg thinned enough to break free of the mound it was trapped on. September 2022. That means there will be a brutal assault on Thwaites from the ocean. An iceberg flotilla is expected to leave from the front following the iceberg leaving the Amundsen Sea and entering Weddel. If he didn’t know, West Antarctica passed the tipping point many years ago.

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