This study investigates the geometric amplification and suppression of ice-shelf basal melt in West Antarctica, focusing on the Amundsen Sea region. The research uses a high-resolution coupled ice–ocean model to simulate the evolution of ice-shelf mass balance over 200 years, incorporating the Pine Island, Thwaites, Crosson, and Dotson ice shelves. The model explores how changes in ice-shelf geometry influence ocean circulation and basal melt rates, revealing significant and sustained changes in melt rates, ranging from a 75% decrease to a 75% increase near the grounding lines, regardless of far-field ocean forcing. These feedbacks between ice-shelf geometry, ocean circulation, and basal melting have a demonstrable impact on the net ice-shelf mass balance, including grounding-line discharge, over multi-decadal timescales. The study highlights the importance of considering these feedbacks in future projections of Antarctic mass loss, alongside changes in ice-shelf melt due to anthropogenic trends in ocean temperature and salinity. The research shows that changes in ice-shelf geometry can significantly affect basal melt rates through complex interactions with ocean dynamics. For example, in the hi_melt experiment, average basal melt rates in the deep interior of the Crosson and Pine Island ice shelves increased by up to 75%, while those for the Dotson Ice Shelf decreased by up to 75%. In the av_melt experiment, similar trends were observed but with a delayed response due to colder ocean thermal driving and slower cavity geometry evolution. The study also demonstrates that the momentum transfer coefficient dominates the melt evolution, with detailed analyses of the underlying dynamical causes for each ice shelf. The findings emphasize the importance of understanding the feedbacks between ice-shelf geometry, ocean circulation, and basal melting in predicting future mass loss from the Antarctic Ice Sheet. The study provides a first step towards more definitive climate change scenario-based projections of mass loss in response to ocean-induced ice-shelf thinning over the next decades to centuries. The results highlight the need for further research into the long-term impacts of these feedbacks on the net mass balance of the West Antarctic ice shelves.This study investigates the geometric amplification and suppression of ice-shelf basal melt in West Antarctica, focusing on the Amundsen Sea region. The research uses a high-resolution coupled ice–ocean model to simulate the evolution of ice-shelf mass balance over 200 years, incorporating the Pine Island, Thwaites, Crosson, and Dotson ice shelves. The model explores how changes in ice-shelf geometry influence ocean circulation and basal melt rates, revealing significant and sustained changes in melt rates, ranging from a 75% decrease to a 75% increase near the grounding lines, regardless of far-field ocean forcing. These feedbacks between ice-shelf geometry, ocean circulation, and basal melting have a demonstrable impact on the net ice-shelf mass balance, including grounding-line discharge, over multi-decadal timescales. The study highlights the importance of considering these feedbacks in future projections of Antarctic mass loss, alongside changes in ice-shelf melt due to anthropogenic trends in ocean temperature and salinity. The research shows that changes in ice-shelf geometry can significantly affect basal melt rates through complex interactions with ocean dynamics. For example, in the hi_melt experiment, average basal melt rates in the deep interior of the Crosson and Pine Island ice shelves increased by up to 75%, while those for the Dotson Ice Shelf decreased by up to 75%. In the av_melt experiment, similar trends were observed but with a delayed response due to colder ocean thermal driving and slower cavity geometry evolution. The study also demonstrates that the momentum transfer coefficient dominates the melt evolution, with detailed analyses of the underlying dynamical causes for each ice shelf. The findings emphasize the importance of understanding the feedbacks between ice-shelf geometry, ocean circulation, and basal melting in predicting future mass loss from the Antarctic Ice Sheet. The study provides a first step towards more definitive climate change scenario-based projections of mass loss in response to ocean-induced ice-shelf thinning over the next decades to centuries. The results highlight the need for further research into the long-term impacts of these feedbacks on the net mass balance of the West Antarctic ice shelves.