Intensifying winds may be causing the largest glacier in East Antarctica to melt from below.
Researchers from the University of Texas at Austin have found that the warmer water beneath the Totten Glacier is due to strong winds, which are becoming stronger due to climate change over the Southern Ocean.
The findings are particularly concerning because the glacier holds more than 11 feet of sea level rise and acts as a plug that helps lock in the ice of the East Antarctic Ice Sheet.
The researchers believe this also sheds light onto what causes Totten melt to speed up some years and slowdown in others. They found that the glacier speeds up its flow toward the sea when the winds over Antarctica’s Southern Ocean are strong, and pull warm water up from the deep ocean onto the continental shelf in a process called upwelling.
When the warm water reaches the coast, it circulates under the floating portion of the glacier via submarine canyons, melting the edge of the ice sheet from below.
When a glacier melts, it thins, weakens and eventually speeds up to let more landlocked ice drain into the ocean, causing sea levels to rise.
Intense winds over the Southern Ocean are considered a byproduct of climate changes, with the winds expected to intensify throughout the next century.
“Totten has been called the sleeping giant because it’s huge and has been seen as insensitive to changes in its environment,” lead author Chad Greene, a Ph.D. candidate at the University of Texas Institute for Geophysics (UTIG), said in a statement. “But we’ve shown that if Totten is asleep, it’s certainly not in a coma—we’re seeing signs of responsiveness and it might just take the wind blowing to wake it up.”
While wind strength varies from year to year, greenhouse gases such as carbon dioxide act like an amplifier to Antarctic coastal winds, boosting their intensity and allowing them to bring up warm water from the depths more frequently.
Deep waters in Antarctica tend to be about five to seven degrees Fahrenheit above freezing, the warmest in the area.