Fig. 4: Changes in surface elevation, h, and speed, V, of Berry Glacier, West Antarctica.

Changes in a h and b V from 2006 to 2022 with GLs in 1996 (white)/2008 (blue)/2009 (cyan) and IGZ boundaries in 2019 (yellow)/2020 (orange)/2021 (red); c, d h and e, f V along profiles G-H and C-D for 1996-2022; g h (grey solid) from WorldView (WV) DEM on Sep 6, 2019, ice draft (blue) deduced from WV (blue solid) and from ICESat-2 DEM for Jan 1, 2020 (dash blue) versus bed elevation from BMv3.7 (dash brown) along G-H. Blue circles are Multichannel Coherent Radar Depth Sounder (MCoRDS) data from 2011-2016; h h (grey solid) from Airborne Topographic Mapper (ATM) from Oct 27, 2012, ice draft (blue) from the ATM for Oct 27, 2012 (dark blue solid) and from the year 2020 ICESat-2 DEM (dash blue) versus bed elevation (dash brown) from BMv3.7 along C-D. Blue circles are MCoRDS data from Oct 27, 2012. Blue shaded areas in (g, b) are the uncertainty of the derived ice drafts. Blue stripey areas in (g) indicate regions where vertical motion from seawater intrusion is detected, but the bed depth remains unknown. White stripey areas in (g) denote regions outside the IGZ where flotation is not applicable and the BMv3.7 bed is not reliable. Brown stripey areas in (h) mark regions where the bed inferred from MCoRDS is not compatible with flotation from 2012 ATM and has been picked erroneously too deep.