Antarctica's subglacial bedrock is mapped more closely using satellites.

Researchers used Ice Flow Perturbation Analysis with satellite ice-surface data and ice-thickness observations to produce the most detailed map yet of Antarctica's subglacial topography, revealing mesoscale valleys and steep-sided channels and indicating where future geophysical surveys could focus.

Researchers have combined satellite observations of the ice surface with a modelling method called Ice Flow Perturbation Analysis (IFPA) to infer the shape of bedrock beneath Antarctica's ice. The team led by Helen Ockenden produced what they describe as the most detailed reconstruction to date of subglacial topography across the continent. The approach uses ice-surface measurements, ice-flow physics and available ice-thickness data from geophysical surveys. The reconstruction resolves features at the mesoscale, roughly 2 to 30 km in size, while smaller landforms remain beyond its current reach. Key findings: - The IFPA method inverts satellite ice-surface data to infer subglacial topography when combined with ice-thickness observations from geophysical surveys. - The new map reveals previously unknown or poorly resolved features, including steep-sided channels and deep, U-shaped valleys that may reflect ancient landscapes. - The reconstruction resolves landforms at the mesoscale (about 1.2 to 18.6 miles, or 2 to 30 km) but does not capture smaller-scale bed features. - These mapped features provide information relevant to understanding ice flow across Antarctica and how the ice sheet may influence future sea-level contributions. - Commentators note that the map can guide where to target more detailed airborne and ground-based geophysical surveys, and they point to the International Polar Year 2031–2033 as a timely opportunity for coordinated observation efforts. Summary: The IFPA-based map offers a finer view of Antarctica’s hidden bedrock and identifies mesoscale valleys and channels that were previously unresolved. The map is presented as a guide for more focused geophysical surveys and for improving models of ice flow and potential sea-level impact, and international observation efforts such as the International Polar Year 2031–2033 are noted as a forthcoming opportunity to build on this work.