In the words of NASA, “several disturbing discoveries” have been brought up by their research survey of the colossal Thwaites Glacier in West Antarctica. On top of the usual story of thinning ice, they found a gigantic cavity – perhaps the size of the Eiffel Tower – growing at the bottom of the vast glacier.
Thwaites Glacier, approximately the size of Florida, once contained over 14 billion tons of frozen water, enough to raise the world's sea level by over 2 feet (65 centimeters). However, huge quantities of this colossal ice cube have melted away over the past three years as a result of climate change, contributing to around 4 percent of global sea level rise.
As reported in the journal Science Advances, researchers have gained a clearer picture of the glacier’s plight. Their findings show that Thwaites Glacier is suffering from extensive ice thinning, receding, and calving, as well as a 300-meter (1,000-foot) hole inside its west wing that’s growing at an “explosive” rate.
"[The size of] a cavity under a glacier plays an important role in melting," study leader Pietro Milillo of NASA’s Jet Propulsion Lab (JPL) said in a statement. "As more heat and water get under the glacier, it melts faster."
A NASA-led team studied the glacier using satellites and specialized planes armed with ice-penetrating radar to provide researchers with high-resolution data about the glacier’s ever-changing shape and size. This data also shed some light on another concern about the glacier's grounding line, the point at which the glacier starts to depart from land and float on the sea. The research has shown that Thwaites Glacier is peeling off from the bedrock beneath it, meaning more of the glacier’s base is exposed to warming waters. In turn, this makes the glacier even more susceptible to melting.
"We have suspected for years that Thwaites was not tightly attached to the bedrock beneath it," said Eric Rignot of the University of California, Irvine, and NASA's JPL. “Thanks to a new generation of satellites, we can finally see the detail."
Thwaites Glacier plays an instrumental role in the story of rising sea levels and climate change, so there's never been more of a drive to study and understand it. Just this week, an icebreaker ship left Chile to begin a scientific expedition to Thwaites Glacier with the help of a number of other ships, researchers, planes, and tagged wild seals.
"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," added Rignot.