Antarctic sea ice has reached a record low for the year, researchers say

(NEW YORK) — Scientists are keeping a close eye on the Antarctic ice shelf as recent activity could soon cause rapid melting and rising sea levels.

The sea ice in Antarctica has likely met its minimum extent for 2023, furthering expectations from researchers that continued melting will occur at a record-fast pace, according to the National Snow and Ice Data Center.

On Feb. 21, at the peak of the region’s summer, the Antarctic sea ice reached its annual minimum extent of 1.79 million square kilometers, or 691,000 square miles — the lowest sea ice extent on record for the second year in a row, according to the center.

This year’s minimum extent was about 52,000 square miles lower than in 2022, the researchers said.

At its maximum extent in September, the sea ice essentially surrounds the Antarctic continent, helping to buffer large floating ice shelves and major outlet glaciers. A decrease in sea ice extent means that ocean waves will pound the coast of the giant ice sheet more furiously, which will further reduce the ice shelves around the Antarctic, Ted Scambos, senior research scientist at the Cooperative Institute for Research in the Environmental Sciences, said in a statement.

Among the larger glaciers are Pine Island and Thwaites — the fastest-melting glaciers in the region, located in the Amundsen Sea in West Antarctica, and are responsible for the largest contribution to sea level rise from the region.

As the sea ice extent decreases, so do the buffers that prevent the vast amount of melting from the glaciers from dumping water into the ocean at high rates, which will create massive waves and cause more major glacial calving events.

Walt Meier, senior research scientist at the University of Colorado’s National Snow and Ice Data Center, told ABC News. Calving events on Pine Island and Thwaites could “could trigger a dramatic increase in sea level rise rates before the end of this century,” Scambos said.

“They help to pin back the glaciers and keep the ice from flying off the land,” Meier said of the sea ice. “But when the ocean is exposed, the ocean heats up, you get waves, that makes those [glaciers] less stable without the sea ice there.”

As global temperatures continue to rise, the melting in Antarctica has not been as rapid as in the Arctic, which has been the “place of action,” Meier said.

“It’s been on a long-term, pretty steep decline,” he said. “We’ve had record lows or near record lows for the last 10 to 15 years.”

The Arctic is warming twice as fast as the rest of the world, amplifying sea level rise and further warming, according to the National Oceanic and Atmospheric Administration. But the current downtrend in sea ice on the South Pole could be a signal that climate change is “finally affecting” the floating ice surrounding Antarctica, Scambos said.

However, the Antarctic summers from 2013 through 2015 saw “near-record” minimum extents, according to the Snow and Ice Data Center, which tracks sea ice by using data from NASA. Scientists are still trying to determine whether the variations in the maximum and minimum extents year by year are a result of natural variation or a more significant indication of the effects of climate change, Meier said.

“It’s too soon to say,” Meier said.

A full analysis of conditions will be released in early March, the center announced.

Copyright © 2023, ABC Audio. All rights reserved.