Lake Palcacocha
A large glacial lake above Huaraz with steep avalanche source zones and substantial downstream exposure.
Supporting sourceGlacier Watch Atlas
Glacier-related hazards and possible movement routes
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The map shows where water, ice or debris might move based on terrain and published sources. It does not predict the exact affected area, depth, speed or arrival time. Do not use this map for emergency decisions.
Documented 2023 flood pathSouth Lhonak Lake → Chungthang · approximately 67.5 km
The 2023 flood reached Chungthang. This map does not predict how far a future outburst could travel.
Confirmed 2023 path to Chungthang
How the historical path was checked
The centreline is a terrain-derived reproduction of the documented 2023 path from South Lhonak Lake to Chungthang. Published research places Chungthang 67.5 km downstream along the river. This is not a calculation of how far a future outburst would travel.
Terrain model135 m cellsElevation5189 → 1642 mRoute-length comparison1.8% from published 67.5 km segmentDestination comparison1.99 km from ChungthangMapzen Terrain TilesPublished route reference
About
About Glacier Watch Atlas
Glacier Watch Atlas brings together glacier-related hazards, possible downstream movement routes, nearby communities and supporting scientific sources in one research interface.
Methodology
How to read the atlas
Entries combine peer-reviewed research and official information with terrain-derived route axes. Confirmed, modelled and potential describe different levels of evidence. A route is not an inundation boundary and does not predict depth, speed or arrival time.
Data sources
Sources and environmental context
Each entry links to its supporting publication or official source. Where available, environmental context may also use Copernicus terrain data, RGI glacier outlines, NASA OPERA satellite classifications, Open-Meteo and WorldPop.
Index
Glacier hazards in this atlas
Imja Tsho
A rapidly evolved proglacial lake with mitigation works, trekking exposure and a complex downstream valley.
Supporting sourceTsho Rolpa
One of Nepal’s best-known monitored lakes, with extensive downstream infrastructure and previous mitigation.
Supporting sourcePlace Glacier
A repeatedly draining lake system above inhabited properties near Gates Lake and Poole Creek, with documented debris floods in 2024, 2025 and 2026.
Supporting sourceSouth Lhonak
A documented cascading flood source in Sikkim, included as a reference event for checking terrain-based routes.
Supporting sourceShisper Glacier
A surge-type glacier with repeated outburst floods and renewed damaging blockage-and-release flows in 2025.
Supporting sourceMerzbacher Lake
A recurrently draining ice-dammed lake in the central Tien Shan with highly dynamic seasonal behaviour.
Supporting sourceSuicide Basin
A recurrent outburst source held by the natural ice dam of Mendenhall Glacier, with direct flood exposure in Juneau.
Supporting sourceFjallsárlón
An emerging mass-movement-triggered lake hazard studied with detailed bathymetry and avalanche scenarios.
Supporting sourceLake 513
A high-altitude lake where ice avalanches can generate displacement waves despite a comparatively strong dam.
Supporting sourceSedongpu Valley
Repeated glacier and ice-rock collapses have moved through Sedongpu Valley and temporarily blocked the Yarlung Tsangpo.
Supporting sourceShuraki Kapali
Several glacier and rock-ice source zones feed one steep catchment. The 2016 detachment transformed into a long debris flow that reached the Surkhob.
Supporting sourceDevdoraki Glacier
Historical and 2014 ice-rock avalanches descended through the Devdoraki–Amali gorge to the Tergi/Terek and the Dariali infrastructure corridor.
Supporting sourceWeisshorn East
An actively monitored upper hanging-glacier source above Randa. Recent break-offs stopped on the glacier plateau.
Supporting sourceBis Glacier
A separate lower icefall above the Matter Valley, monitored independently from the upper Weisshorn East source.
Supporting source