Understanding and anticipating dynamical changes as Greenland Ice-Sheet outlet glaciers Transition from Marine- to Land-terminating

In TransMariLand, we aim to quantitatively understand the physics controlling MorPoFee and predict its impact on Ice-Sheet evolution and sea-level rise from paleo-climatic timescales to coming centuries.

This proposed research pushes beyond the state of the art not only because it builds up on a recent change of paradigm regarding Greenland susceptibility to surface meltwater, but also because it involves a particularly innovative monitoring strategy based on seismic and satellite observations to probe key differences in marine- versus land-terminating subglacial hydrology characteristics and fill long-lasting knowledge gaps on subglacial hydrology and basal sliding. Contrary to observations of basal water pressure in boreholes, seismic and geodetic observations are by nature non-local and allow to retrieve multi-scales spatial fields that can more easily be confronted to models at considerably reduced financial cost and human resources enabling systematic investigations in remote areas like Greenland. Although proofs of concepts exist, yet a multi-scale monitoring strategy combined with dedicated modelling enabling making full sense of observations has not been conducted, nor in Greenland nor elsewhere. The plan of investigation is structured through two overlying aims gathering 5 work packages that all have their own independent merit, but taken together will synergistically provide unprecedent and quantitative insights.

Innovative use of seismology. The field of seismology underwent a particularly large diversification over the past decade. Recent discoveries, to which we actively contributed, suggests that dedicated array designs, signal processing schemes and theoretical frameworks allow locating both channel and cavity drainage with high spatial and temporal resolution, inferring cavity network structure and evolutions as well as channel pressure and size.

Innovative use of geodesy. New satellite sensors and improved processing schemes now put satellite observations at another level of increased temporal and spatial coverage and resolution. We have recently demonstrated that differential radar interferometry (DInSAR) allows investigating centimetric changes in surface motion resulting from underneath fluid migrations, such that flow pathways and velocities are inferred over large areas of several hundreds of kilometers.

Updated on 10 September 2024