I use in-situ data, remotely-sensed data, traditional and novel sensors and algorithms, and low-cost robotic platforms to investigate glaciers, glacier hydrology, and the ice/ocean boundary.
I have mapped approximately 100 m of a subglacial conduit at mm resolution. The conduit was accessed by rapelling down a moulin in Hornsund, Svalbard, after a lake drainage event. These conduits have two opposing influences on the overhead ice: Either they act as high-pressure sources, contributing additional water to the distributed system and glacier bed, reducing basal friction, and accelerating the ice toward the sea, or they act as low-pressure sinks, drawing in water from their surroundings and reducing glacier velocity. I am co-advising a student who is using the digital conduit maps as boundary conditions for a computational fluid dynamics model, and will examine the effects of skin and form roughness on the water pressure within the subglacial conduit.
Conduit mapping was funded by the Svalbard Science Forum and National Geographic. CFD simulations funded by the National Science Foundation award # 1503928.
Greenland Meltwater Runoff and Ice/Ocean Interactions
Observations of marine-terminating glaciers in Greenland (and Antarctica) show that increased velocity, thinning, and retreat is contributing to accelerating sea level rise. Increasing surface melt, runoff, and frontal melting are contributing increasing freshwater fluxes into Greenland fjords and into the downstream oceanic system.
These fjords are the connection between the warming North Atlantic waters and the melting ice front, and the complex dynamical processes in them are not fully understood. My research focuses on the subglacial outflow, and how that buoyant freshwater plume mixes into the fjord.
Pine Island Glacier Ice Shelf
Pine Island Glacier ice shelf, the floating tongue of the fastest ice stream in West Antarctica, has experienced recent acceleration and thinning, primarily due to rapid melting by relatively warm ocean waters accessing the grounding zone and base of the ice shelf.
While sub-ice shelf outflow plumes had long been assumed and occasionally observed at the edge of other ice shelves, and modeled at the PIG ice shelf, my observations confirmed the sub-shelf plume at this location. More recent additional work on PIG has shown high melt rates in the upstream sub-shelf basal conduits, and that sub-shelf conduits are both widespread and connected to upstream subglacial hydrology.