Seasonal velocity patterns provide insights for the soft-bed subglacial hydrology continuum.

Abstract

Subglacial hydrology plays an important role in controlling glacier behaviour, influencing glacier retreat and the resulting contributions to sea level rise. Here we present a detailed seasonal data set from four soft-bedded temperate glaciers and demonstrate a continuum of subglacial hydrology from channelized to a multichannel distributed behaviour. Our results illustrate how this continuum may be affected by till grain size and subaqueous processes, and we quantify the relative timings of basal sliding and deformation. These different hydrologies have a distinctive seasonal velocity pattern, which although have been identified using a multi-data stream, we suggest can be classified using solely Sentinel-1 satellite-based glacier velocity data. The ability to categorize subglacial glacier hydrology over a much larger data set would allow a better parameterization of subglacial processes for ice sheet models.