A comprehensive and version-controlled database of glacial lake outburst floods in High Mountain Asia

Abstract

Abstract. Glacial lake outburst floods (GLOFs) have been intensely investigated in High Mountain Asia (HMA) in recent years and are the most well-known hazard associated with the cryosphere. As glaciers recede and surrounding slopes become increasingly unstable, such events are expected to increase, although current evidence for an increase in events is ambiguous. Many studies have investigated individual events, and while several regional inventories exist, they either do not cover all types of GLOF or are geographically constrained. Further, downstream impacts are rarely discussed. Previous inventories have relied on academic sources and have not been combined with existing inventories of glaciers and lakes. In this study, we present the first comprehensive inventory of GLOFs in HMA, including details on the time of their occurrence, processes of lake formation and drainage involved, and downstream impacts. We document 697 individual GLOFs that occurred between 1833 and 2022. Of these, 23 % were recurring events from just three ephemeral ice-dammed lakes. In combination, the documented events resulted in 6906 fatalities of which 906 can be attributed to 24 individual GLOF events, which is 3 times higher than a previous assessment for the region. The integration of previous inventories of glaciers and lakes within this database will inform future assessments of potential drivers of GLOFs, allowing more robust projections to be developed. The database and future, updated versions are traceable and version-controlled and can be directly incorporated into further analysis. The database is available at https://doi.org/10.5281/zenodo.7271187 (Steiner and Shrestha, 2023), while the code including a development version is available on GitHub.

Shaking up Assumptions: Earthquakes Have Rarely Triggered Andean Glacier Lake Outburst Floods

“…None of this implies that a future earthquake could not trigger a catastrophic GLOF, but the data clearly indicates that, in the region and timeframe of study, large earthquakes rarely ever trigger any GLOFs. This supports research focused on smaller regions, such as the case of the M7.8 2015 Gorkha earthquake in Nepal (Kargel et al, 2016) and more recent database for High Mountain Asia (Shrestha et al, 2023). A notorious exception is the 1970 Perú earthquake (Emmer, 2017;Emmer et al, 2020Emmer et al, , 2022bHubbard et al, 2005;Lliboutry et al, 1977;Zapata, 2002), which we consider in the next section.…”

Enhanced glacial lake activity threatens numerous communities and infrastructure in the Third Pole

“…The GLOFs that occurred after 1900 and originated from moraine-dammed lakes were compiled (Table S2 ) by integrating several available GLOF datasets, such as those created by Zhang et al 13 , Shrestha et al 14 , and Veh et al 25 . Many outburst floods produced by ice-dammed lakes or those without reliable data were not included (for example, Zheng et al 24 ).…”

“…It had a 40-km runout distance and destroyed a hydropower plant in Nepal 12 . Since 1900, more than 110 GLOFs originating from such moraine-dammed lakes have been recorded in the Third Pole and have claimed ~7000 lives 13 , 14 . The Himalayas, Nyainqentanglha, and Tianshan Mountains serve as the main sources of GLOFs in the Third Pole.…”

Remote Sensing and Modeling of the Cryosphere in High Mountain Asia: A Multidisciplinary Review

“…The first comprehensive GLOFs inventory in HMA documented that 697 individual floods occurred between 1833 and 2022, as compiled from peer-reviewed papers, news articles, reports, books, and communications [12]. To date, several glacier lake inventories in HMA have been derived from optical images.…”

“…As HMA's cryosphere changes [2,3], cryospheric-related disasters have occurred, such as rockice avalanches [4,5], glacier collapses or detachments [6,7], debris flow [8], landslides [9], and glacial lake outburst floods (GLOFs) [10,11]. Historical data demonstrate that there were 697 individual GLOFs that occurred in HMA from 1833 to 2022, resulting in 6906 fatalities [12]. More recent data indicate that there were 681 snow and ice avalanche events that occurred in HMA between 1972 and 2022, resulting in more than 3100 fatalities [13].…”