Melting of West Antarctic ice sheet could trigger catastrophic reshaping of the land beneath
A picture of what West Antarctica looked like when its ice sheet melted in the past can offer insight into the continent’s future as the climate warms.
Due to its thick, vast ice sheet, Antarctica appears to be a single, continuous landmass centered over the South Pole and spanning both hemispheres of the globe. The Western Hemisphere sector of the ice sheet is shaped like a hitchhiker’s thumb – an apt metaphor, because the West Antarctic ice sheet is on the go. Affected by Earth’s warming oceans and atmosphere, the ice sheet that sits atop West Antarctica is melting, flowing outward and diminishing in size, all at an astonishing pace.
Much of the discussion about the melting of massive ice sheets during a time of climate change addresses its effects on people. That makes sense: Millions will see their homes damaged or destroyed by rising sea levels and storm surges.
In layers of sediment accumulated on the sea floor over millions of years, researchers like us are finding evidence that when West Antarctica melted, there was a rapid uptick in onshore geological activity in the area. The evidence foretells what’s in store for the future.
Aboard the drillship JOIDES Resolution, workers lowered a drill nearly 13,000 feet (3,962 meters) to the sea floor and then drilled 2,605 feet (794 meters) into the ocean floor, directly offshore from the most vulnerable part of the West Antarctic ice sheet.
The drill brought up long tubes called “cores,” containing layers of sediments deposited between 6 million years ago and the present. Our research focused on sections of sediment from the time of the Pliocene Epoch, when Antarctica was not entirely ice-covered.
Cover photo: The ice that now covers West Antarctica was not there 3.6 million years ago, after a massive collapse of the ice sheet during a warming period. (Image credit: Anna Ruth Halberstadt / CC BY-NC-ND)
