Grounding line retreat and tide-modulated ocean channels at Moscow University and Totten Glacier ice shelves, East Antarctica

Abstract. The Totten and Moscow University glaciers, located in East Antarctica, contain 5.1 m sea-level equivalent of ice have been losing mass over recent decades. Using ICESat-2 laser altimetry repeat track analysis satellite radar interferometry from Sentinel-1a/b synthetic aperture (SAR) images, we mapped the grounding line (GL) locations these two glaciers between 2017 2021. By comparing 2017–2021 GL measurements with historic GLs, detected pervasive retreats along plains at glacier central trunk Glacier Ice Shelf (TGIS) (MUIS). retreated 3.51±0.49 km TGIS, while it 13.85±0.08 MUIS 1996. CryoSat-2 altimetry, found that observed are coincident high thinning rates, addition to velocities, indicating a loss pattern dominated by dynamics. We also identified tide-modulated ocean channels on Eastern (TGEIS) Western (MUWIS), where channel widths highly correlated differential tidal amplitudes. opening MUWIS connects previously separated TGIS systems, which might open pathway for warm modified Circumpolar Deep Water enter main cavity facilitate further retreat.