Videos of Subglacial Till Dynamics

Abstract

During a field campaign at Rhonegletscher in summer 2018 we drilled several holes through 190 m ice to the glacier bed. We deployed a borehole camera approximately 15 cm above the glacier bed in different boreholes for a timespan of 20 days in total. The presented dataset contains two time lapse videos of the borehole camera that shows the basal till dynamics on a time scale of hours. Additionally, one video shows how we actively dug into the till. The videos show that basal till reacts highly dynamic on water pressure changes. From digging into the till, it can be seen that the till below Rhonegletscher is only poorly consolidated. Finally, the grain size distribution of the subglacial till can be estimated.