Today’s Image of the Day from NASA Earth Observatory features an old area of sea ice breaking up near Land Glacier in West Antarctica. According to NASA, as new ice was forming in March, part of the glacier’s ice tongue crumbled away.
The sea ice around Antarctica is starting to gain momentum after reaching its lowest extent on record in late February 2022.
Michael Lowe is an analyst at the U.S. National Ice Center. He recognized the changes near Land Glacier – part of the Antarctic coastline known as Marie Byrd Land.
“I’ve had my eye on that area over the past two months as a large area of very old fast ice began to break apart,” said Lowe. “When comparing two SAR images from consecutive days I saw that the tip of the Land Glacier was starting to break up.”
An earlier satellite image that was captured in February showed a vast expanse of sea ice fastened to the Land Glacier’s ice tongue and icebergs. Lowe explained that this “fast ice” often has a symbiotic relationship with glaciers and icebergs.
“The glaciers and grounded bergs allow sea ice to accumulate and ‘fast’ in a stable fashion,” said Lowe. “This fast ice then helps anchor those bergs and glaciers as it thickens into old ice over years.”
A recent analysis of satellite observations revealed that fast ice off the coast of Marie Byrd Land, and in other parts of Antarctica as well, has been decreasing since around 2000.
According to Frazer Christie, a glacier geophysicist at the University of Cambridge, the loss of fast ice may have further consequences. It is possible, he said, that the quick evacuation of fast ice between February and March, in addition to the longer-term losses, may have contributed to the rifting and ultimate calving of Land Glacier’s ice tongue.
“An increasing body of research has begun to show the important role sea ice plays in congealing together and buttressing both ice tongues and ice shelves,” said Christie.
“While Land Glacier has been observed to retreat, thin, and speed up in recent years, there is no evidence to suggest that its recent calving is related to anthropogenically forced climate change.” “Instead, its behavior most likely reflects the natural calving lifecycle common to all Antarctic ice shelves and marine terminating glaciers.”
The image was captured on March 23, 2022 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua satellites.
Image Credit: NASA Earth Observatory
By Chrissy Sexton, Earth.com Staff Writer