Damage strength increases ice mass loss from Thwaites Glacier, Antarctica

Abstract. Ice damage plays a critical role in determining ice-shelf stability, grounding-line retreat, and subsequent sea-level rise, as it affects the formation and development of crevasses on glaciers. However, few ice-sheet models have explicitly considered ice damage nor its effect on glacier projections. Here, we incorporate ice damage processes into an ice-sheet model. By applying the upgraded model to the Thwaites Glacier basin, we further investigate the sensitivity of Thwaites Glacier to the strength of the ice damage. Our results indicate that the ice-sheet model enabled with the ice damage mechanics better captures the observed ice geometry and mass balance of the Thwaites Glacier during the historical period (1990–2020), compared to the default model that ignores ice damage mechanics. Ice damage may result in a collapse of Thwaites Glacier on multidecadal-to-centennial timescales and a notable increase in ice mass loss. Moreover, ice mass loss from Thwaites Glacier to the ocean may induce a sea-level rise of 5.0 ± 2.9 cm by 2300, which is more than double the simulation result without ice damage. This study highlights the importance of explicitly representing ice damage processes in ice-sheet models.