The ice dynamic and melting response of Pine Island Ice Shelf to calving

• Published in: Annals of Glaciology
• Main Authors: Alexander T. Bradley, Jan De Rydt, David T. Bett, Pierre Dutrieux, Paul R. Holland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2022
• Subjects: Calving; ice/ocean interactions; ice shelves; ice-sheet modelling; polar and subpolar oceans; Meteorology. Climatology; QC851-999; Pine Island Glacier; Annals of Glaciology; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: https://doi.org/10.1017/aog.2023.24; https://doaj.org/article/3c5184c7aa964900b9268bc899e5695e

Sea level rise contributions from the Pine Island Glacier (PIG) are strongly modulated by the backstress that its floating extension – Pine Island Ice Shelf (PIIS) – exerts on the adjoining grounded ice. The front of PIIS has recently retreated significantly via calving, and satellite and theoretical analyses have suggested further retreat is inevitable. As well as inducing an instantaneous increase in ice flow, retreat of the PIIS front may result in increased ocean melting, by relaxing the topographic barrier to warm ocean water that is currently provided by a prominent seabed ridge. Recently published research (Bradley and others, 2022a) has shown that PIIS may exhibit a strong melting response to calving, with melting close to the PIG grounding line always increasing with ice front retreat. Here, we summarise this research and, additionally, place the results in a glaciological context by comparing the impact of melt-induced and ice-dynamical changes in the ice shelf thinning rate. We find that while PIG is expected to experience rapid acceleration in response to further ice front retreat, the mean instantaneous thinning response is set primarily by changes in melting, rather than ice dynamics. Overall, further ice front retreat is expected to lead to enhanced ice-shelf thinning, with potentially detrimental consequences for ice shelf stability.