[Paper Review] Earthquake-induced hazards in mountain regions: a review of case histories from Central Asia -- an inaugural lecture to the society

Hans‐Balder Havenith, Céline Bourdeau|Open Repository and Bibliography (University of Liège)|Jan 15, 2024

Landslides and related hazards5 citations

TL;DR

This paper reviews trigger factors for earthquake-induced landslides in Central Asia and surveys case histories of major seismic landslide events, highlighting two particularly disastrous mass movements and the need for mid- to long-term slope monitoring.

ABSTRACT

This paper presents a summary of the main trigger factors of earthquake-induced landslides as well as a review of case histories of major landslide-triggering earthquake events in Central Asia. The Kainama earth-flow case history of 2005 is added to document possible mid-term effects of smaller earthquakes. These events show that in the Central Asian Mountains, two types of seismically triggered mass movements may have particularly disastrous effects: massive long runout rockslides and medium-sized earth flows made of loess -- or a mixture of both. These types of mass movements also significantly contributed to the largest natural catastrophe of the last century in Central Asian mountain regions: the 1949 Khait earthquake.The high impact potential of these types of mass movements is further pointed out through comparison with two worldwide known events, the 1920 Haiyuan (China) and the 1976 Peru earthquake.Case studies had been carried out on rockslides, debris slumps and earth flows triggered by the above-mentioned Kemin and Suusamyr earthquakes as well as other smaller seismic shocks in the Kyrgyz Tien Shan. Many of the investigated landslides had known a complex failure history before final collapse. To better assess the short- to long-term effects of earthquakes on slopes, landslides need to be surveyed more intensively, over mid- and long-terms.

Motivation & Objective

• Summarize the main trigger factors of earthquake-induced landslides in Central Asia.
• Review case histories of major seismically triggered landslides in Central Asian mountains.
• Document potential mid-term and long-term effects of earthquakes on slopes.
• Highlight mass movement types with high impact potential in the region.
• Advocate for intensified mid- and long-term landslide surveys after earthquakes.

Proposed method

• Review of historical earthquake-induced landslide case histories in Central Asia.
• Incorporation of the Kainama earth-flow 2005 case to illustrate mid-term effects of smaller earthquakes.
• Comparison with globally known events (Haiyuan 1920, Peru 1976) to contextualize mass movement impacts.
• Assessment of failure histories of investigated landslides to understand complex failure processes.

Experimental results

Research questions

• RQ1 What are the primary trigger factors for earthquake-induced landslides in Central Asia?
• RQ2 Which landslide types have the highest potential for disaster in Central Asian mountains?
• RQ3 What do case histories reveal about short-, mid-, and long-term effects of earthquakes on slopes?
• RQ4 How do Central Asian cases compare to notable international earthquake-triggered landslides?

Key findings

• Two seismically triggered mass movement types show particularly disastrous potential: massive long runout rockslides and medium-sized loess earth flows (or mixtures).
• Several landslides exhibit complex failure histories prior to collapse.
• The 1949 Khait catastrophe is linked to these mass movements in Central Asian mountains.
• The Kemin and Suusamyr earthquake cases, along with other shocks in the Kyrgyz Tien Shan, underpin the regional hazard relevance.
• Mid- and long-term surveying of landslides is needed to better assess earthquake impacts on slopes.
• Comparisons with Haiyuan (1920, China) and Peru (1976) provide broader context for the scale of potential events.