Three Recent and Lesser-Known Glacier-Related Flood Mechanisms in High Mountain Environments

Abstract

Glacial lake outburst floods, and specifically those triggered by avalanche-induced seiche waves, have been studied in considerable detail during the past several decades. Less attention has been given to other cryospheric flood phenomena, which include floods sourced primarily from englacial conduits, permafrost-linked rockfall and avalanches, and earthquake-Triggered glacial lake floods. The article reviews examples of each phenomenon, based on field sampling and laboratory analyses, that have occurred in the Nepal Himalaya during the past decade, drawing parallels with similar events in other countries throughout the high mountain world. In most cases, the frequency of these events appears to be increasing globally, as is their potential to inflict significant damage downstream. We argue that each type of glacier flood requires more detailed study to develop the most effective prevention, mitigation, and adaptation approaches possible. Such studies will most likely be strengthened if they include a reconnaissance of the event as soon after its occurrence as possible, along with the participation, insights, and experience of local people, in addition to the use of increasingly powerful remote sensing technologies. How scientists can more quickly and effectively share the results of their research with decision-makers, and how decision-makers and governments can deliver more timely mitigation programs, are areas that also require further strengthening.