Analysis of Glacial Lake Outburst Flood Terrain and Sedimentary Deposits in Valle Soler, Northern Patagonia Icefield

Glacial lake outburst floods (GLOFs) pose an increasing hazard to communities living downstream of glaciated areas due to a proliferation of glacial lakes in both size and quantity, a result of increased warming in recent years. Many outlet glaciers of the Northern Patagonia Icefield (NPI) have experienced several catastrophic GLOFs in recent decades. Understanding past events will help to understand and prepare for future occurrences. This study utilizes satellite imagery, supplemented by high-resolution unmanned aerial vehicle (UAV) imagery derived from 3D models, to understand the hydrodynamics of a GLOF which took place March 16, 1989, in the Valle Soler of the NPI. Using the 3D digital elevation model (DEM) and satellite-derived DEM, flood parameters are evaluated to describe this significant GLOF event. Calculated flood volume was in excess of 135,000,000 m³ while the peak discharge was likely between 50,000-60,000 m³/s. This newly calculated flood discharge value distinguishes this event as the largest recorded glacial moraine outburst flood in the literature and is significantly larger than previous estimates (1,800 - 2,000 m³/s) for this incident.