NERC. HYDRO-RIFT: Observing and modelling hydrofracture across the Antarctic Peninsula
Lead Research Organisation:
UNIVERSITY OF CAMBRIDGE
Abstract
The Antarctic Ice Sheet has the potential to raise global sea levels by 58 m, and even a partial collapse would have catastrophic consequences for low-lying coastal communities worldwide. Ice shelves are the gatekeepers of such collapse. These floating extensions of the ice sheet buffer grounded ice contributions to sea level rise. Several Antarctic ice shelves are showing increasing signs of vulnerability to collapse, largely driven by rising air and ocean temperatures. This is clearest on the Antarctic Peninsula, where large-scale ice-shelf disintegration has been linked to surface meltwater-driven fracture. This process, known as hydrofracture, occurs when meltwater fills and pressurizes surface cracks - often pre-existing weakness, such as crevasses, until the water-pressure exceeds the surrounding ice-pressure, causing rapid fracture. With atmospheric temperatures set to rise further under all future emissions scenarios, surface melting, and therefore the potential for hydrofracture-driven ice-shelf collapse, is expected to increase. Despite its significance, direct observations of this process remain limited, both from satellites and in-situ measurements, and our understanding of the fracture mechanics involved is still incomplete.
To address this important knowledge gap, this study aims to directly observe ice-shelf hydrofracture events on the Antarctic Peninsula. This will be achieved by instrumenting fractures at sites that have been identified - through satellite evidence - as having experienced hydrofracture during recent melt seasons. Each site is centred on a previously collapsed surface lake basin, known as a doline, which represents a known location for focussed, repeated hydrofracture activity. Four dolines will be studied in detail across the Wilkins and Bach ice shelves. At each site, instruments previously used successfully by the British Antarctic Survey to measure dry fractures on the Brunt Ice Shelf will be redeployed to capture data in wet ice-shelf environments. These will be supplemented by newly developed water pressure sensors, capable of real-time data collection. The resulting dataset will constitute the first-ever direct field observations of ice-shelf hydrofracture.
By reproducing these observed hydrofracture events using the KRAKEN fracture model, we aim to simulate the far-field stress state before, during and after events to assess their larger scale context, and, in particular, assess whether isolated hydrofracture events can cascade, trigger neighbouring events, and potentially initiate widespread ice-shelf collapse. The outcomes of this research will enable improved parameterisation of meltwater-driven fracture processes, enhancing predictive models of ice-shelf stability. Ultimately, these advances will support more reliable projections of Antarctic contributions to future sea-level rise under various climate scenarios.
To address this important knowledge gap, this study aims to directly observe ice-shelf hydrofracture events on the Antarctic Peninsula. This will be achieved by instrumenting fractures at sites that have been identified - through satellite evidence - as having experienced hydrofracture during recent melt seasons. Each site is centred on a previously collapsed surface lake basin, known as a doline, which represents a known location for focussed, repeated hydrofracture activity. Four dolines will be studied in detail across the Wilkins and Bach ice shelves. At each site, instruments previously used successfully by the British Antarctic Survey to measure dry fractures on the Brunt Ice Shelf will be redeployed to capture data in wet ice-shelf environments. These will be supplemented by newly developed water pressure sensors, capable of real-time data collection. The resulting dataset will constitute the first-ever direct field observations of ice-shelf hydrofracture.
By reproducing these observed hydrofracture events using the KRAKEN fracture model, we aim to simulate the far-field stress state before, during and after events to assess their larger scale context, and, in particular, assess whether isolated hydrofracture events can cascade, trigger neighbouring events, and potentially initiate widespread ice-shelf collapse. The outcomes of this research will enable improved parameterisation of meltwater-driven fracture processes, enhancing predictive models of ice-shelf stability. Ultimately, these advances will support more reliable projections of Antarctic contributions to future sea-level rise under various climate scenarios.