The behaviour of ice sheets, ice shelves, and glaciers is strongly influenced by the geology, structure, and evolving boundary conditions of the solid Earth beneath and around them. From mantle dynamics and crustal architecture to subglacial topography, geothermal heat flux, and basement geology, these boundary conditions influence ice-sheet and ice-shelf dynamics and their response to climate change. However, their representation in the numerical models used to project future sea-level rise remains subject to significant uncertainties. Growing amounts of geological and geophysical data from Antarctica, Greenland, and other ice-covered regions have improved our understanding of these solid Earth–ice interactions, yet many connections between geological boundary conditions and ice-sheet, ice-shelf, and glacier behaviour remain poorly constrained. This session seeks to bring together research spanning mantle-to-crustal-scale processes, tectonic and geodynamic controls (e.g., rifting, uplift, exhumation), and surface and subglacial boundary conditions (e.g., subglacial topography, sub-ice shelf bathymetry, geothermal heat flux, subglacial geology, basal sediment and water distribution) that together provide critical constraints on ice behaviour.

This session aims to link deep Earth processes with the boundary conditions that govern ice-sheet and ice-shelf behaviour, thus aiming to foster dialogue across the solid Earth, geodynamics, and cryosphere communities and to explore implications for past, present, and future ice stability. While we anticipate particular interest in the Cenozoic evolution of the Antarctic and Greenland ice sheets, contributions addressing older glacial events and the deeper-time geological drivers of glaciation are equally welcome. Contributions addressing solid Earth-ice interactions across a range of spatial and temporal scales are encouraged, and we invite studies using geophysical measurements, geological and geochronology data, and/or numerical geodynamic/landscape-evolution/ice-sheet modelling approaches.