Satellite data reveals significant Antarctic grounding line retreat despite stability across most coastlines

Satellite data from 1992 to 2025 shows significant ice retreat in West Antarctica, with 12,800 sq km of grounded ice lost despite stability elsewhere.

By: AXL Media

Published: Mar 3, 2026, 7:39 AM EST

Source: The information in this article was sourced from ESA

Monitoring critical boundaries of the Antarctic Ice Sheet

New research published in the Proceedings of the National Academy of Sciences (PNAS) has provided a comprehensive record of changes to Antarctica’s grounding lines, the vital boundaries where ice transitions from resting on land to floating in the ocean. These lines are considered primary indicators of ice sheet stability and are highly sensitive to changes in sea level. The study, which utilizes three decades of satellite data including missions from Copernicus Sentinel-1, offers new insights into how the world’s largest ice sheet is responding to the warming of global sea temperatures.

Observations of stability and regional vulnerability

The study mapped the grounding lines around the entire Antarctic continent from 1992 to 2025, finding that more than three quarters of the coastline remained largely stable. Major ice shelves, including the Ross, Amery, and Filchner-Ronne, showed little movement over the thirty year period. However, this stability is contrasted by dramatic retreats in vulnerable sectors. The most significant withdrawal was recorded in West Antarctica along the Amundsen Sea coast, where ice has retreated by as much as 42 kilometers in certain areas. Regions surrounding the Pine Island, Thwaites, Smith, and East Getz ice sheets were identified as the most heavily affected.

Mechanisms of ice loss and ocean interaction

The research highlights the role of warm ocean currents, specifically Circumpolar Deep Water, in driving ice retreat. Scientists found that melting is most pronounced where these currents reach deep glacier beds through underwater channels. These areas are particularly susceptible because the underlying bedrock slopes downward as it moves inland, creating a feedback loop that facilitates continued retreat. Furthermore, the study clarified that the grounding line is not a static boundary but part of a dynamic "grounding zone" that shifts in response to subglacial water processes and ocean tides.