Seasonal velocity patterns and deforming bed processes associated with different subglacial drainage systems.

Abstract We use a series of unique techniques (wireless in situ subglacial probes; web connected GNSS) along with remotely sensed data to record a continuum of subglacial hydrology from channelized to braided behaviour associated with four soft bedded temperate glaciers. We argue this continuum may be affected by till grain size and subaqueous processes. In addition, we are able to quantify sedimentary processes associated with these different hydrologies. Although we have used a multi-data stream here, we suggest it is possible to solely use glacier velocity data, derived from Sentinel-1 imagery, to distinguish the different hydrological types. This is important because the water at the base of the glacier (in both water bodies and the till) is a key driver of glacier behaviour and the rate of sea level rise, but direct measurements of the basal environment are rare, hence the importance of our remote sensing data.