Blind spots at Antarctic coasts limit sea level projections

The Antarctic coastal zone is a complex system where ice from the ice sheet interfaces with the ocean and solid Earth. This area plays a crucial role in determining the future of the Antarctic ice sheet and its impact on sea-level rise. However, key coastal conditions remain poorly mapped, with significant knowledge gaps in direct observations of coastal bed topography and sub-ice-shelf cavities.

These gaps hinder accurate predictions of Antarctic ice loss and future sea-level rise, as ice sheet models are highly sensitive to coastal conditions. Current satellite observations provide valuable measurements of ice motion and surface change but cannot observe the bedrock under ice from space. Similarly, computer models alone cannot predict future changes without accurate knowledge of bed topography.

While airborne measurements of ice thickness, ice bed, and cavities beneath ice shelves can help close this knowledge gap, current observations remain sparse, increasing uncertainty in understanding and future projections. International coordination is essential to address these challenges, as no single nation can achieve comprehensive coverage alone.

The review article, published in Reviews of Geophysics, brings together 80 scientists from 16 countries working across various disciplines. It emphasizes the need for long-term, coordinated measurement programs and close international cooperation to better predict future changes in the Antarctic ice sheet and their impact on the ocean, climate, and global sea level.