Thirty-three years of glacier grounding line retreat in Antarctica 1992-2025

The Grounding Line (GL) - the transition from ice grounded on the continent and ice afloat in the ocean - is a sensitive indicator of glacier stability and mass balance. Using differential SAR interferometry from ERS-1/2, Sentinel-1, RADARSAT-1/2, RCM, ALOS PALSAR-2, COSMO-SkyMed, and ICEYE, we assemble a continental scale record of grounding line migration from 1992 to 2025. Over 77±10% of Antarctic coastal length, we detect no GL migration. Stable areas include the vast Ross, Filchner-Ronne, Amery and West ice shelves, and broad sectors of Coats, Queen Maud, Enderby, and Princess Elizabeth Lands. Retreat is concentrated in (i) the Antarctic Peninsula - 2-18 km along Larsen A-B and 2-6 km along parts of GeorgeVI, and no change on Larsen C-D ice shelves; (ii) Wilkes and GeorgeV lands - 6-10 km on Denman, Totten, Moscow, Frost, Holmes, Mertz, Ninnis, and Cook, and 26 km on Vanderford; and (iii) West Antarctica - 5-7-km on Ferrigno, Fox, and Venable, with extreme retreat in the Amundsen a..., SAR Missions. We use radar interferometry (InSAR) observations from several satellite Synthetic-Aperture Radar (SAR) missions. The European Space Agency (ESA) Earth Remote Sensing ERS-1 collected repeat-pass interferometry at the C-band frequency (5.3 GHz) in 1992 and 1994 (3-day repeat). ESA collected data at a one-day repeat with ERS-1 and ERS-2 in 1995/1996. ERS-1 acquired 3-day repeat data at the end of its mission in 2000. ERS-2 acquired 3-day repeat data at the end of its mission in 2011. ESA launched Sentinel-1a in 2014, followed by Sentinel-1b in 2016, which acquired SAR data at the C-band frequency (5.4 GHz) with a 6 to 12 day repeat until Sentinel-1b ceased operations in 2021. Sentinel-1c was launched in December 2024 and collected data at a one-day repeat with S1a for one month over the Amundsen Sea. The Japanese Space Agency (JAXA) launched the ALOS PALSAR in 2006 to acquire SAR data at the L-band frequency (1.27 GHz) at a 44-day repeat until 2011. In 2014, JAXA launched ALO..., # Thirty-three years of glacier grounding line retreat in Antarctica 1992-2025

Dataset DOI: [10.5061/dryad.p2ngf1w4h](10.5061/dryad.p2ngf1w4h)

## Description of the data and file structure

***The grounding line delineations***, **InSAR_GL_Antarctica_v1-1992-2025.gpkg** and **.shp** are distributed as a geopackage file (gpkg) and ESRI shape files which include the following fields

Each double difference is made from 3 to 4 images which correspond to 3 to 4 orbits and 3 to 4 dates. When the set is limited to that, it simply means that the middle image is used twice, once to make a pair forward in time, once to make a pair backward. 

**Sensor:** **String**. Name of the satellite constellation used to collect the data. Values are: CSK (CosmoSkyMed), Sentinel-1, RSAT-1 (RADARSAT-1), RCM (RADARSAT Constellation Mission), ALOS (ALOS PALSAR-2 and 3 missions), ERS (Earth Remote Sensing Satellite 1 and 2), ICEYE (ICEYE X6 and X7 satellites, with a few data acquired with X38). 

**Orbit_1: In..., , **Changes after Sep 24, 2025:** Update to the GL files with additional data.