Collaborative Research: Observing melt-forced subglacial hydrologic connectivity and its impact on ice sliding with coupled hydrology and geophysical methods

About This Grant

The investigators will explore how meltwater from surface channels called moulins (holes in the ice that funnel water downward) affects the hidden drainage system beneath Greenland’s glaciers. They will conduct a field study to see how water connects isolated pockets of space at the glacier’s base with larger drainage networks and how these connections influence seasonal changes in ice speed. The team will use tools like seismic sensors, radar, and measurements of ice movement to track how these systems evolve together. By observing changes in the number, size, and location of these underground cavities over time - linked to how much meltwater flows in - they will determine how the hydrological connections between these spaces affect how fast the ice is moving. This research builds on earlier discoveries showing that Greenland’s summer slowdowns (when glaciers move less) happen not because water channels grow larger, as seen in mountain glaciers like those in the Alps, but because isolated pockets under the ice merge into bigger drainage pathways. The study will focus on western Greenland’s Paakitsoq region. The investigators will create a Virtual Reality (VR) module showcasing fieldwork on the Greenland Ice Sheet in partnership with the Museum of the Earth (Ithaca, NY) and the Kangiata Illorsua-Icefjord Center (Ilulissat, Greenland). The investigators will conduct a field campaign focused on understanding how hydraulic connections between isolated cavities at the bed surface of the Greenland Ice Sheet and the broader distributed subglacial drainage system evolve, and how this "connectivity" affects the seasonal changes in ice velocity. The team will integrate ice dynamic, hydrologic, and geophysical (seismic and radar) methods to monitor the co-evolution of moulin-connected subglacial channels, well-connected regions of the distributed system, and hydraulically isolated bed cavities. By quantifying changes in cavity number, size, and spatial distribution over time - linked to observed meltwater inputs - the researchers will assess how bed cavity connectivity modulates ice motion. This work aligns with findings from the Greenland Ice Sheet (GrIS) observations, which show that summer slowdowns occur not due to conduit expansion (as seen on Alpine glaciers) but through increased connectivity within the distributed system as isolated bed cavities integrate into larger drainage pathways. The field campaign will focus on the Paakitsoq region of western GrIS, where supraglacial meltwater inputs are monitored to trace their subglacial impacts. Understanding these processes is critical for predicting how future meltwater increases will influence GrIS mass loss, particularly as seasonal connectivity changes modulate ice flow and stability. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.