Antarctica's ice shelves could be melting faster than we thought

The study was conducted in the laboratory of Andy Thompson, professor of environmental science and engineering, and appears in the journal Science Advances on August 12.

Ice shelves are outcroppings of the Antarctic ice sheet, found where the ice juts out from land and floats on top of the . The shelves, which are each several hundred meters thick, act as a protective buffer for the mainland ice, keeping the whole ice sheet from flowing into the ocean (which would dramatically raise global sea levels). However, a warming atmosphere and warming oceans caused by are increasing the speed at which these are melting, threatening their ability to hold back the flow of the ice sheet into the ocean.

"If this mechanism that we've been studying is active in the real world, it may mean that ice shelf melt rates are 20 to 40 percent higher than the predictions in global climate models, which typically cannot simulate these strong currents near the Antarctic coast," Thompson says.

In this study, led by senior research scientist Mar Flexas, the researchers focused on one area of Antarctica: the West Antarctic Peninsula (WAP). Antarctica is roughly shaped like a disk, except where the WAP protrudes out of the high polar latitudes and into lower, warmer latitudes. It is here that Antarctica sees the most dramatic changes due to climate change. The team has previously deployed autonomous vehicles in this region, and scientists have used data from instrumented elephant seals to measure temperature and salinity in the water and ice.

Prior to developing this model, the team has traveled to Antarctica to make measurements of temperature and salinity of the water and ice. Their new model shows that an often-overlooked narrow ocean current along the Antarctic coast can play a large role in how heat gets trapped beneath the ice shelves, melting them from below. Credit: Andy Thompson

Researchers traveling to Antarctica to take measurements of ocean temperature and salinity. Credit: Andy Thompson

An ice shelf in the distance as researchers take measurements of temperature and salinity off the coast of Antarctica. Credit: Andy Thompson