Jessica Mejia: Cracks in the Ice: Using observations and models of crevasse growth to understand the transport of water to the base of glaciers and ice sheets
Presentations
The Greenland Ice Sheet is a major contributor to global sea level rise, driven by both increased melting and dynamic ice discharge into the ocean. While often treated separately, these processes are interconnected because when surface meltwater flows into crevasses—cracks on the ice sheet surface—they can hydrofracture through the entire ice sheet and reach the bed. Once surface meltwater reaches the ice-bedrock interface it can modulate subglacial water pressures, the structure of the subglacial drainage system, and influence ice dynamics.
In this talk, Jessica will focus on recent work understanding these hydraulic connections. First, she will discuss how far inland these hydraulic connections can extend into the ice sheet’s interior using coupled observational, remote sensing, and modeling applied to the firn aquifer on Helheim Glacier in southeast Greenland. Next, she will discuss in situ observations of crevasse opening and what it means for firn aquifer drainage. Finally, Jessica will discuss some modeling work applied to rapid hydraulically driven fracture propagation from the fast drainage of supraglacial lakes on the Greenland Ice Sheet.
