The Hindu-Kush Himalaya is a region that is commonly known as the third-pole given the volume of glacier ice that is stored in the mountains – more than anywhere on earth outside the Arctic and Antarctica. These water towers also feed the world’s most densely populated countries; the Brahmaputra and Indus basins alone provide water for an estimated 60 million people. Yet predictions of glacier mass loss in high Asia are severely limited by data availability and assumptions made in the parameterisation of glacier models. Consequently, projections of glacier change vary widely; in Nepal, recent estimates of volumetric ice loss by AD2100 have ranged between 8 and 99%. In particular, data describing glacier bed topography, ice thickness, ice temperature, basal water pressures, bed composition and 3D strain are lacking.

This project, EverDrill, will revolutionise the way in which dynamic debris-covered glacier models are parameterised, by accessing and installing sensors in the interior and at the bed of a large Himalayan glacier for the first time. We will use pressurised hot-water to drill several boreholes into the Khumbu Glacier, Nepal. We will gather visual footage of the interior of each borehole and install a multi-sensor array at the bed at each location. At select boreholes we will install englacial temperature and tilt strings to determine the 3D thermal and deformation profiles of the glacier. Combined, these data will offer transformative potential by providing an unprecedented insight into the physical structure and dynamics of a Himalayan glacier and the processes that operate englacially and at the bed. By incorporating these data into our state-of-the-art 3-D dynamic glacier model we will make the first ever predictions of Himalayan glacier evolution and their future contribution to river flow based on real-world data, thereby dramatically improving forecasts for regional and international policy makers (through, for example, IPCC AR6), governments, aid agencies, and global development programmes.