Two decades of dynamic change and progressive destabilization on the Thwaites Eastern Ice Shelf

Abstract. The Thwaites Eastern Ice Shelf (TEIS) buttresses the eastern grounded portion of Glacier through contact with a pinning point at its seaward limit. Loss this ice shelf will promote further acceleration Glacier. Understanding dynamic controls and structural integrity TEIS is therefore important to estimating Thwaites' future sea-level contribution. We present ? 20-year record change on that reveals governing shelf's past behaviour ongoing evolution. derived velocities from MODIS Sentinel-1 image data using feature tracking speckle tracking, respectively, we combined these records ITS_LIVE GOLIVE velocity products Landsat-7 Landsat-8. In addition, estimated surface lowering basal melt rates Reference Elevation Model Antarctica (REMA) DEM in comparison ICESat ICESat-2 altimetry. Early record, flow dynamics were strongly controlled by neighbouring Western Tongue (TWIT). Flow patterns changed following disintegration TWIT around 2008, new divergence developing Simultaneously, developed rifting extends shear zone upstream rise increased strain concentration within zone. As horizontal changes occurred, sustained thinning driven reduced thickness, particularly near grounding line area point. This evidence weakening rapid pace suggests likely fully destabilize next few decades, leading