An abseil down a knickpoint, during a descent to the bottom of the Larsbreen glacier above Longyearbyen, Svalbard. This photo was taken during a scientific mission to map the caves and channels within the glacier. These channels are eroded by meltwater rivers during the summer months and shift their configuration annually. Mapping the changes and specifically the movement of knickpoints gives an indication of how much water has flowed through the glacier during the preceding summer.