Seismology of iceberg calving
One of the peculiarities of ice is that it remains brittle all the way up to the melting point. Because of this, ice flows like a very viscous fluid (think thick molasses) and fractures like a brittle solid (think about a plate shattering when you drop it). A consequence of this behavior is that glaciers flow out into the ocean and while they do this they start to break up. The bits of ice that break off are icebergs. One of the ways in which we can monitor the iceberg calving process is by looking at the seismic waves generated as the ice fractures. One project that I’ve been involved with seeks to try to characterize the myriad different processes that cause ice to break based on the seismic waveform. We think this will allow to better understand the processes that cause ice to break and ultimately are responsible for iceberg calving. You can read about some work done in collaboration with Fabian Walter and Shad O’Neel here.
Geodynamics of icy moons
Despite the fact that water covers two thirds of the surface of the Earth, Earth is considered a “rocky” planet. This is because most of the interior of the planet is made up of, well, rock. Icy moons such as Europa (a relatively small moon orbiting Jupiter) have a crust that consists primarily of ice. (To a glaciologist, that makes Europa or any other icy moon a glorified ice sheet.) Europa is actually a bit more interesting than that in that it appears to have a subsurface ocean. This means the moon consists of a layer of ice sitting on top of a saline ocean. Europa is not unique, Enceladus is an icy moon orbiting Saturn. However, the existence of an ocean beneath the icy crust of Enceladus is much more controversial. Catherine Walker, a student working with me, is interested in understanding if icy moons, and in particular the way in which icy moons fracture, is at all similar to how ice sheets and glaciers fracture.