In another study, researchers from the University of Texas at Austin found that coastal Antarctic permafrost—which, unlike Arctic permafrost, was considered to be stable—is actually melting much faster than scientists had expected. Researchers had though that the permafrost in the region was in equalibrium—ice would melt during the summer, only to refreeze in the winter. But the Texas study, published in Scientific Reports, shows a rapid melting of permafrost in Antarctica’s Garwood Valley, diminishing the overall mass of ground ice. “The big tell here is that ice is vanishing—it’s melting faster each time we measure,” said Joseph Levy, a research associate at the University of Texas’s Institute for Geophysics and the lead author on the paper.
“That’s a dramatic shift from recent history.”
It’s important to note that global warming is not responsible for the permafrost melt here—that region of Antarctic actually experienced a cooling trend from 1986 to 2000, followed by relatively stable temperatures. The Scientific Letters researchers suggest instead that the melting is due to an increase in radiation from sunlight resulting from changing weather patterns that allow more light to reach the ground during the summer. (In the winter, of course, Antarctica experiences 24-hour darkness.) As the permafrost melts, it actually alters the land surface, creating “retrogressive thaw slumps.” The changes observed in the study are occurring around 10 times faster than the average during the Holocene, the current geological epoch, and can actually be seen with time-lapse photography