Phys.org June 25, 2024
Recently published studies of the complex hydrography of grounding zones suggest that warm ocean water can intrude large distances beneath the ice sheet, with dramatic consequences for ice dynamics. Researchers in the UK developed a model to capture the feedback between intruded ocean water, the melting it induces and the resulting changes in ice geometry showing a sensitive dependence of the grounding-zone dynamics on this feedback: as the grounding zone widens in response to melting, both temperature and flow velocity in the region increase, further enhancing melting. They found that increases in ocean temperature could lead to a tipping point being passed, beyond which ocean water intrudes in an unbounded manner beneath the ice sheet, this tipping point may not be easily detected with early warning indicators. This suggests a mechanism for dramatic changes in grounding-zone behaviour, which are not currently included in icesheet models. According to the researchers their results point towards a stronger sensitivity of icesheet melting, and thus higher sea-level-rise contribution in a warming climate, than has been previously understood… read more. Open Access TECHNICAL ARTICLEÂ
Complex grounding zones of ice sheets. Credit: Nature Geoscience, 25 June 2024