The deepest geoid low on Earth and its possible relation to the instability of the West Antarctic Ice Sheet ...

• Main Authors: Steinberger, Bernhard, Grasnick, Maya-Laureen, Ludwig, Ronja
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Antarctic; Ross Sea; West Antarctic Ice Sheet; West Antarctica; Antarc*; Antarctica; Ice Sheet
• Online Access: https://dx.doi.org/10.57757/iugg23-0176; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016369

<!--!introduction!--> The deepest geoid low globally w.r.t. hydrostatic equilibrium is in the Ross Sea area. Nearby in West Antarctica is a residual topography high. Both are in a region with thin lithosphere, where a mantle plume has been suggested. Hence upper mantle viscosity could be regionally reduced, allowing for faster rebound than elsewhere upon melting of the West Antarctic Ice Sheet, one of the global climate system's tipping elements. To study possible causes of the geoid low / topography high combination, we compute the effects of disk-shaped density anomalies. With -1% density anomaly, geoid low and topography high can be explained with disk radius ~10° and depth range ~150-650km. Alternatively, there may be two separate disks somewhat laterally displaced, one just below the lithosphere and mainly causing a dynamic topography high and one below the transition zone causing the geoid low. In order to test the feasibility of such density models, we perform computations of a plume that enters ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...