Arrive at Thwaites and map an unexplored seabed


Nathaniel B. Palmer arrived at the Thwaites Glacier at approximately 26:00 ET on February 26, almost a month after leaving Chile. On the first day at Thwaites, the Palmer traced a trail of about 100 miles around the glacier and above it in the Amundsen Sea.

During the hike, the researchers mapped parts of the seabed in front of the glacier that were not yet mapped.

These maps will help scientists understand what happened with Thwaites in the past and its future behavior, allowing models to better predict how well Florida-sized ice could contribute to the future. Sea level rise over the next few decades.

"It sounds pretty mystical," said Peter Sheehan, oceanographer at the University of East Anglia in the UK. "It's like standing in a cathedral, you feel the silence of reverence."

Snow layers, compacted over time, are visible up the Thwaites Glacier. In areas where ice moves more slowly, these layers, such as tree rings, can help scientists date glaciers.

The Amundsen Sea was particularly motionless during the first day of Palmer at Thwaites, which allowed the ship to get closer to the glacier than expected. Lieutenant-Commander Rick Wiemken, sailing in uncharted waters, said he had kept about a quarter of a mile off the face of the glaciers to reduce any risk of iceberg calving for the vessel.

As the Palmer sailed west along the Thwaites face, the glacier front became increasingly broken and chaotic – visual signs of its instability.

The glacier fronts are generally relatively uniform, with vertical fronts like cliffs. The wavy summit and gentle slope off Thwaites in many places, as well as in Thwaites' recently calmed icebergs, are also signs of its volatility.

The Thwaites Glacier begins ashore and empties into the Amundsen Sea, forming a vast ice platform floating above a water hole never studied before.

"We know more about the moon than about this part of the Earth," says Anna Wahlin, an oceanographer at the University of Gothenburg who hopes to send an automated submarine near Thwaites on this expedition.

"It's a critical boundary in the world today," said British Antarctic Survey chief scientist Rob Larter, observing the glacier on the morning of his arrival.

"This is where the quick changes really happen, and we are looking at what is changing rapidly."

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