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.But what will happen to Antarctica itself as the ice sheets melt?AdvertisementAdvertisementAdvertisementAdvertisementIn 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.A voyage of discoveryAs far back as 30 million years ago, an ice sheet covered much of what we now call Antarctica. But during the Pliocene Epoch, which lasted from 5.3 million to 2.6 million years ago, the ice sheet on West Antarctica drastically retreated. Rather than a continuous ice sheet, all that remained were high ice caps and glaciers on or near mountaintops.About 5 million years ago, conditions around Antarctica began to warm, and West Antarctic ice diminished. About 3 million years ago, all of Earth entered a warm climate phase, similar to what is happening today.Glaciers are not stationary. These large masses of ice form on land and flow toward the sea, moving over bedrock and scraping off material from the landscape they cover, and carrying that debris along as the ice moves, almost like a conveyor belt. This process speeds up when the climate warms, as does calving into the sea, which forms icebergs. Debris-laden icebergs can then carry that continental rock material out …
