9 Cenozoic Tectonics in Asia and North America: Linking Processes Across Scales (Posters)

This session invites research integrating geologic, geomorphic, and paleoclimate data to advance understanding on orogenesis, seismic hazards, and global change.

Monday, 18 May 2026
8:00 AM - 5:30 PM
Alvarado D/E

Landslide Hazards in the Altai Mountains, Western Mongolia

Paper number: 9-0
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

The Altai Mountains of western Mongolia consists of the Mongolian Altai and the Gobi-Altai, each distinguished by unique transpressive settings likely linked to far-field crustal deformation associated with the Indo-Eurasian collision. This study seeks to establish a connection that links large earthquakes and massive landslides, characteristic of both ranges, and establish a framework for understanding the natural hazards that impact a rapidly growing infrastructure and human population in western Mongolia. On December 4, 1957, one of the strongest measured intracontinental earthquakes (M 8.3) occurred along the Valley of Lakes in the Gobi-Altai range, specifically on the eastern segment of the Bogd fault. This region is known for several long strike-slip faults with other large historic ruptures, including the Chandmani (Mmax7.8), Ikh Bogd (Mmax8.1), and Tsagaan gol (Mmax7.8) earthquakes. The steep flanks of the Mongolian and Gobi Altai formed by these active fault segments are scalloped by massive landslides including the Burhan Buudai Mountain landslide (3765 m) in the western part of the Gobi-Altai range. This landslide has a width of ~17.5 km, a length of ~16 km, a main head scarp slope angle of ~37°, and an estimated volume of ~56 km³. We document a recent, large event, the Tsambagarav mountain landslide, that occurred on July 27, 2021, in the Erdeneburen area of Khoyd Province. Here, residents reported a loud roaring sound at midnight, and by morning, a massive landslide was observed covering ~42 km², destroying 20 ha of forest in its path, and impacting 62 ha of regional habitat. This event was apparently triggered by snowmelt and heavy rain accumulating at the permafrost front in the soil. Similarly, we have undertaken a reconnaissance survey to determine the causes, trends, and spatial distribution of an even more recent mountain landslide that occurred on December 27, 2024, in the territory of Dzereg soum, Khovd Province. These events highlight the ongoing risk of landslides due to climate-change driven by increases in soil water infiltration, rising lake levels, and extreme flooding. Our goal is to understand how similar future landslides and their associated hazards can be characterized when earthquakes are introduced as a primary triggering mechanism, or as an antecedent mechanism that primes slopes for failure prior to hydro-climatic triggers.

Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410538

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