Developing conceptual models for the recognition of coseismic landslides hazard for shallow crustal and megathrust earthquakes in different mountain environments – an example from the Chilean Andes

Abstract

Landslides represent the most frequent geological hazard in mountainous environments. Most notably, landslides are a major source of fatalities and damage related to strong earthquakes. The main aim of this research is to show through three-dimensional engineer-friendly computer drawings, different mountain environments where coseismic landslides could be generated during shallow crustal and megathrust earthquakes in the Andes of central Chile. We have determined topographic, geomorphological, geological and seismic controlling factors in the occurrence of earthquake-triggered landslides from: (1) a comparison of local earthquake-induced landslide inventories in Chile (the Mw 6.2, shallow crustal Aysén earthquake in 2007 (45.3° S) and the Mw 8.8, megathrust Maule earthquake in 2010 (32.5°S–38.5°S)) with others from abroad; and (2) analysis of large, prehistoric landslide inventories proposed as likely induced by seismic activity. With these results, we have built four representative geomodels of coseismic landslide geomorphological environments in the Andes of central Chile. Each one represents the possible landslide types that could be generated by a shallow crustal earthquake v. those likely to be generated by a megathrust earthquake. Additionally, the associated hazards and suggested mitigation measures are expressed in each scenario. These geomodels are a powerful tool for earthquake-induced landslide hazard assessment.Thematic collection: This article is part of the Ground models in engineering geology and hydrogeology collection available at: https://www.lyellcollection.org/cc/Ground-models-in-engineering-geology-and-hydrogeology

Submarine landslide susceptibility assessment along the southern convergent margin of the Colombian Caribbean

“…After mapping the geographic distribution of submarine landslides reported by Rincon et al, 2021 (Figure 2), its relation with ground conditions including seafloor geomorphology, slope degree, and faults presence, was analyzed. For this purpose, we present bathymetric images and conceptual models (Serey A et al, 2020) to condense the main geomorphological features observed on the seafloor. In addition, looking for evidence connecting gas hydrate dissociation and submarine landslides, we analyzed the position of landslide glides concerning the Bottom Simulator Reflector (BSR) (McIver, 1982;Kayen and Lee, 1993;Kvenvolden, 1993;Miniert et al, 2005;Talling et al, 2014;Mountjoy, 2014;Wu et al, 2018).…”

The likely Quaternary active El Arrayán fault, Santiago, Chile

“…1b; e.g. Serey et al, 2020). Therefore in the absence of absolute dates, the tectonic geomorphology constitutes important chronological support.…”

Modeling and Evaluation of the Susceptibility to Landslide Events Using Machine Learning Algorithms in the Province of Chañaral, Atacama Region, Chile

“…In Chile, landslides are one of the most common geological hazards, together with earthquakes, volcanic activity, and floods. The geological, geomorphological, tectonic, and climatic conditions of the country, characterized by the presence of the Andes Mountain Range on its eastern margin and the Coastal Mountain Range on its western margin, make it highly susceptible to the generation of mass movements such as landslides, rockfalls, flows, and falls [10]. Within 52 declared events in Chile, there have been a total of 1010 fatal victims caused by landslides, corresponding to 882 deaths and 128 people missing between 1928 and 2017 (90 years) [11].…”