The base of the Antarctic Ice Sheet plays a key role in how the ice flows and responds to changes in climate and heat from Earth’s interior. However, scientists still know very little about what lies beneath the thick ice in the high, central part of East Antarctica because it is extremely remote and difficult to reach.

To learn more, we deployed hundreds of seismic sensors along two survey lines near the South Pole over two field seasons. These instruments recorded distant earthquakes, and by analyzing how the earthquake waves changed as they traveled through the Earth, we discovered signs of a soft, wet layer directly beneath the ice.

This layer appears to be made of water-saturated sediments and stretches across a large region. Its presence suggests that parts of the ice sheet base may be thawed and slippery, which could affect how the ice moves over time. Our findings provide new clues about the hidden environment beneath the ice and highlight how seismic imaging can help scientists understand ice sheet behavior in one of the least explored regions on Earth.