Investigating Relationships between Lake Drainages and Surge Motion through Modeling in the Karakoram Himalaya

Glacier motion, retreat, and hazards like surges and glacial lake outburst floods (GLOF) are strongly affected by subglacial hydrology. In High Mountain Asia, surges and GLOF, which have caused billions in damages in recent decades, occur in the context of increasingly negative mass loss, erratic weather patterns, and dwindling water resources. While surges and GLOF have generally been studied separately, observations at surge-type glaciers in the Karakoram Range of Pakistan exhibit identical patterns of concurrent surge termination and GLOF, implying that both phenomena may be connected to changes in subglacial hydrology. Here, we build on previous modeling work with SHAKTI (Subglacial Hydrology and Kinetic, Transient Interactions) that demonstrated that seasonal subglacial hydrology alone is insufficient to explain observed velocity changes. We use a coupled subglacial hydrology and ice dynamics framework to investigate how ice-dammed lake outbursts affect the motion of surging glaciers. We then demonstrate the effects of lake bathymetry and glacier geometry on flood characteristics and ice motion.