摘要:∼0.2 m) is widespread several kilometers upstream of the grounding zone. Our results are consistent with previous inferences of gradual grounding zones across this sector of the Ross Ice Shelf from airborne radar and satellite altimetry. Separately, the only clear bed-reflectivity change that we observed occurs ∼40 km downstream of the Kamb Ice Stream grounding zone, which we attribute to the onset of marine ice accretion onto the base of the ice shelf. This onset is much nearer to the grounding zone than previously predicted.