Modeling Northern Hemispheric Ice Sheet Dynamics, Sea Level Change, and Solid Earth Deformation Through the Last Glacial Cycle

Retreat or advance of an ice sheet perturbs the Earth's solid surface, rotational vector, and the gravitational field, which in turn feeds back onto the evolution of the ice sheet over a range of timescales. Throughout the last glacial cycle, ice sheets over the Northern Hemisphere have gone through multiple growth and retreat phases, but the dynamics during these phases are not well understood. In this study, we apply a coupled ice sheet-glacial isostatic adjustment model to simulate the Northern Hemisphere Ice Sheets over the last glacial cycle. We focus on understanding the influence of solid Earth deformation and gravitational field perturbations associated with surface (ice and water) loading changes on the dynamics of terrestrial and marine-based ice sheets during different phases of the glacial cycle. Our results show that solid Earth deformation enhances glaciation during growth phases and melting during retreat phases in terrestrial regions through ice-elevation feedback, and gravitational field perturbations have a stabilizing influence on marine-based ice sheets in regions such as Hudson Bay in North America and Barents and Kara Seas in Eurasia during retreat phases through sea-level feedback. Our results also indicate that solid Earth deformation influences the relative sensitivity of the North American and Eurasian ice sheets to climate and thus the timing and magnitude of their fluctuations throughout the last glacial cycle.