Melting Antarctic glacier could increase global sea levels 8 feet

Jan. 31 (UPI) -- A large hole under an Antarctic glacier is a sign of rapid decay that could lead to dramatic sea level rise, a study says.

A cavity two-thirds the size of Manhattan and nearly 1,000 feet tall is growing beneath Thwaites Glacier in West Antarctica, according to study published Wednesday in the journal Science Advances.

"We have suspected for years that Thwaites was not tightly attached to the bedrock beneath it," Eric Rignot, a researcher at NASA's Jet Propulsion Laboratory and study author, said in a news release. "Thanks to a new generation of satellites, we can finally see the detail."

Researchers discovered the cavity during Operation IceBridge, an aerial expedition launched in 2010 to explore the relationship between polar regions and the global climate. They used NASA's ice-penetrating radar to get their data.

"[The size of] a cavity under a glacier plays an important role in melting," said Pietro Milillo, a NASA researcher and study lead author. "As more heat and water get under the glacier, it melts faster."

Thwaites Glacier has nearly the mass of Florida and accounts for 4 percent of global sea level rise. If all of the ice melted, the world's ocean level would rise over two feet. The Thwaites Glacier melting could also lead to nearby glaciers melting, which could lift sea levels around the world an additional eight feet.

Researchers hope these new findings will help other scientists better understand the connection between the weather and glaciers.

"Such data is essential for field parties to focus on areas where the action is, because the grounding line is retreating rapidly with complex spatial patterns," Milillo said.

"Understanding the details of how the ocean melts away this glacier is essential to project its impact on sea level rise in the coming decades," Rignot said.