Analysis of glacial lake outburst flood terrain and sedimentary deposits in Valle Soler, Northern Patagonia Icefield

Abstract

ABSTRACT Glacial lake outburst floods (GLOFs) pose an increasing hazard to communities living downstream of glaciated areas of the Northern Patagonia Icefield (NPI). The proliferation of GLOF events poses a growing hazard to human development and infrastructure which is rapidly expanding into formerly isolated areas. The outlet glaciers on the eastern flank of the NPI, in particular, have experienced an increase in the frequency of GLOFs, threatening downstream communities with the potential for future events. Using a satellite-derived DEM and UAV imagery, we evaluated flood parameters of a 16 March 1989 GLOF event in the Valle Soler. Calculated flood volume was in excess of 140 × 106 m3 while the peak discharge was approximately 20,000 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.