Review status: a revised version of this preprint is currently under review for the journal ESurf.
Earthquake-induced debris flows at Popocatépetl Volcano, Mexico
Velio Coviello1,Lucia Capra2,Gianluca Norini3,Norma Dávila4,Dolores Ferrés2,Víctor Hugo Márquez-Ramirez2,and Eduard Pico2Velio Coviello et al.Velio Coviello1,Lucia Capra2,Gianluca Norini3,Norma Dávila4,Dolores Ferrés2,Víctor Hugo Márquez-Ramirez2,and Eduard Pico2
Received: 27 Apr 2020 – Accepted for review: 20 May 2020 – Discussion started: 25 May 2020
Abstract. The M7.1 Puebla-Morelos earthquake that occurred on 19 September 2017, with epicenter located ∼ 70 km SW from Popocatépetl volcano, severely hit central Mexico. Seismic shaking of the volcanic edifice induced by the earthquake triggered hundreds of shallow landslides on the volcanic flanks, remobilizing loose pyroclastic deposits and saturated soils. The largest landslides occurred on the slopes of aligned ENE-WSW-trending ravines on opposite sides of the volcanic cone, roughly parallel to the regional maximum horizontal stress and local volcanotectonic structural features. This configuration may suggest transient reactivation of local faults and extensional fractures as one of the mechanisms that has weakened the volcanic edifice and promoted the largest slope failures. The seismic records from a broadband station located at few kilometers from the main landslides are used to infer the intensity of ground shaking that triggered the slope failures. The material involved in the larger landslides, mainly ash and pumice fall deposits from late Holocene eruptions with a total volume of about 106 cubic meters, transformed into two large debris flows on the western slope of the volcano and one on its eastern side. The debris flows were highly viscous and contained abundant large woods (about 105 cubic meter). Their peculiar rheology is reconstructed by field evidences and analyzing the grain size distribution of samples from both landslide scars and deposits. This is the first time that such flows were observed at this volcano. Our work provides new insights to constrain a multi-hazard risk assessment for Popocatépetl and other continental active volcanoes.
The Puebla-Morelos earthquake (19 September 2017) was the most damaging event in central Mexico since 1985. The seismic shaking produced hundreds of shallow landslides on the slopes of Popocatépetl volcano. The larger landslides transformed into large flows of sediment and water that travelled for kilometres. We describe this dramatic mass-wasting cascade and its predisposing factors, which have important implications for both the evolution of the volcanic edifices and for hazard assessment.
The Puebla-Morelos earthquake (19 September 2017) was the most damaging event in central Mexico...