( A) Bathymetry with notations indicating bathymetric features and areas discussed in the main text. Orange dots indicate conductivity-temperature-depth (CTD) cast locations. 1).Ĭolors indicate bathymetry according to color bar, unsurveyed areas appear smoother as bathymetry from gravity inversion ( 7) is shown, and black solid line shows ice shelf and melange front in mid-February 2019. This basin beneath the Eastern Ice Shelf extends eastward to a 1400-m-deep area, partially separated from Pine Island Trough by an irregular ridge ( Fig. This northern front of the Thwaites Ice Shelf provides access to the main deep basin at the grounding zone, but there is also an eastern-facing front that provides access to a more eastern deep basin, separated from the main basin by a submarine ridge ( Fig. These troughs branch from a 1300-m-deep northern basin (Thwaites Trough) that connects to Pine Island Trough further north along the continental shelf. 1), which are hypothesized, in turn, to direct warm dense water into the cavity, potentially accessing the base of the ice shelf and grounding zones. These inversions predict the existence of three deep troughs at the northern ice front (“T1”, “T2”, and “T3” in Fig. Direct observations of water depth are lacking in the coastal vicinity and ice-shelf cavity therefore, all studies so far have used estimates of bathymetry derived from inversions of airborne gravity survey data ( 7, 8).

The Thwaites Ice Shelf consists of the faster flowing Thwaites Glacier Tongue and the slower flowing Eastern Ice Shelf ( Fig.

Seven ice extreme v2