A Giant 12,000-Year-Old Ice Shelf in Antarctica Could Melt By 2020 (Video)

May 16, 2015 Updated: May 17, 2015

The Larsen B Ice Shelf in Antarctica, which suffered a partial collapse in 2002, is rapidly disintegrating and is expected to melt completely by 2020, according to a report produced by NASA’s Jet Propulsion Laboratory.

Large cracks are developing and the glaciers are thinning out rapidly.

“Although it’s fascinating scientifically to have a front-row seat to watch the ice shelf becoming unstable and breaking up, it’s bad news for our planet,” Ala Khazendar, one of the authors of the report, said in a statement. “This ice shelf has existed for at least 10,000 years, and soon it will be gone.”

Ice shelves are named after their service as “gatekeepers.” They keep glaciers from floating and melting into the ocean, which would contribute to rising sea levels. The NASA report on Larsen B was based on data collected during a multiyear airborne survey of Antarctica’s glaciers, including their elevation and bedrock depth.

The prognosis for the Larsen B’s swift destruction is founded on the expectation that a large rift in the ice shelf will develop into a fatal crack that will split the ice block into two, one of which will float into the sea and disintegrate into hundreds of fragments.

“What is really surprising about Larsen B is how quickly the changes are taking place,” Khazendar said. “Change has been relentless.”

The Larsen B has a surface area of around 625 square miles, and is more than 1,640 feet deep at its thickest point. The ice block is at least 400 years old according to studies of its sediments, and scientists believe that it has existed since the last glaciation period 12,000 years ago.