hide
Free keywords:
-
Abstract:
Some of the most destructive mountain cryosphere hazards are those that generate far-traveled flows, most notably glacial lake outburst floods (GLOFs), but also mass wasting or glacial collapse triggered flows. These events can travel 10s to 100s of kilometers downstream through the fluvial network, and the processes that take place during this propagation may play a significant role in the magnitude and type of impact that such events have on both downstream communities and the fluvial system. While there has been substantial progress in our understanding of the past occurrence, potential sources and triggers, and initial stages of such events, particularly GLOFs, there are still a number of key open questions about their subsequent behavior. Understanding the interaction between propagating flows and the water, sediment, and channel properties they encounter as they propagate downstream is critical for the accurate estimation of the hazard potential of possible flow sources. These questions are highlighted by the complexity of several recent large events in the Himalaya, including the 2021 Chamoli event, the 2021 Melamchi flood, and the 2016 Bhote Koshi GLOF. Using new techniques such as environmental seismology, combined with advances in remote sensing and observer documentation, we can make progress towards understanding the evolution of such events as they propagate downstream.
