SEAS Events

About the presentation: The ice underside in freshwater lakes of various sizes has been observed to be appreciably rough as a function of flow oscillations and pressure ridging in large open lakes, and variability in snow depth modifying the conductive heat flux (i.e. freezing rates) of the lake. In the case of an underwater oil pipeline rupture occurring in the winter, consolidated ice cover serves to both retain buoyant oil and mask the location of the oil to clean-up crews. The storage capacity of freshwater ice is a function of the roughness of the ice-water interface, the magnitude and correlation length of which varies dependent on the weather from year to year. This presentation focuses on preliminary investigations in the Straits of Mackinac which indicates that ice bottom variability in a region with considerable oscillatory flow is 0.3 m3 per m2, similar to that of first year sea ice. Additionally, the implication of ice-bottom roughness also extend to studies with the aim to improve the understanding of microwave interactions with freshwater ice (observed with airborne and spaceborne platforms), which holds potential to detect the presence of under-ice oil.

About the speaker: Dr. Gunn is an Assistant Professor in the Department of Geography and Environmental Management at the University of Waterloo (Canada) and formerly in the Department of Geography at Michigan State University. His expertise lies in the remote observation and retrieval of freshwater ice systems in sub-Arctic and Arctic environments. His research applies emerging technologies including airborne/spaceborne synthetic aperture radar, high-performance cloud computing (e.g. Google Earth Engine), interferometry, polarimetric decomposition and thermodynamic modeling. During his time at MSU, Dr. Gunn investigated the variability of ice properties using ground penetrating radar in the Straits of Mackinac to understand the holding capacity of oil under freshwater ice in the event of a spill in the Great Lakes.