Probabilistic Volcanic Hazard Assessment of the 22.5–28°S Segment of the Central Volcanic Zone of the Andes

Abstract

Evaluation of volcanic hazards typically focusses on single eruptive centres or spatially restricted areas, such as volcanic fields. Expanding hazard assessments across wide regions (e.g., large sections of a continental margin) has rarely been attempted, due to the complexity of integrating temporal and spatial variability in tectonic and magmatic processes. In this study, we investigate new approaches to quantify the hazards of such long-term active and complex settings, using the example of the 22.5–28°S segment of the Central Volcanic Zone of the Andes. This research is based on the estimation of: 1) spatial probability of future volcanic activity (based on kernel density estimation using a new volcanic geospatial database), 2) temporal probability of future volcanic events, and 3) areas susceptible to volcanic flow and fall processes (based on computer modeling). Integrating these results, we produce a set of volcanic hazard maps. We then calculate the relative probabilities of population centres in the area being affected by any volcanic phenomenon. Touristic towns such as La Poma (Argentina), Toconao (Chile), Antofagasta de la Sierra (Argentina), Socaire (Chile), and Talabre (Chile) are exposed to the highest relative volcanic hazard. In addition, through this work we delineate five regions of high spatial probability (i.e., volcanic clusters), three of which correlate well with geophysical evidence of mid-crustal partial melt bodies. Many of the eruptive centres within these volcanic clusters have poorly known eruption histories and are recommended to be targeted for future work. We hope this contribution will be a useful approach to encourage probabilistic volcanic hazard assessments for other arc segments.

An evaluation of the General Bathymetric Chart of the Ocean in shoreline-crossing geomorphometric investigations of volcanic islands

“…The attempt of Zorn et al (2022) to find potentially tsunamigenic volcanoes in Indonesia, by creating a ranking system based on globally available datasets, for example, can potentially be improved with additional information below the sea level. With an extensive database, a probabilistic volcanic hazard approach, similar to the methods of Bertin et al (2022) will become possible.…”

Gathering insights into volcanic risk from Auckland to the Andes, Antilles, and Arabia: an unexpected journey to professorship in volcanology

“…A recent highlight for me has been to rekindle my interest in the Central Andes by co-supervising a Chilean PhD student, Daniel Bertin, who developed a comprehensive volcanic database and volcanic hazard assessment for the region (Bertin et al, 2022;Bertin et al, 2023). It was particularly rewarding to co-supervise Daniel with Shan de Silva, my former adviser.…”

Revisiting the Holocene tephrochronology of northwestern Argentina: Insights from geochemical characterization of the tephras from the Tafí valley

“…Unlike the Southern Volcanic Zone (SVZ), which has recorded dozens of historic eruptions from several volcanoes (Dzierma and Wehrmann, 2012), in the southernmost sector of the CVZ, only the Lascar volcano records confirmed historical explosive eruptions (Gardeweg et al, 1998). However, it should be considered that most of the volcanoes in this region have little or no information about their eruptive history, especially for the Holocene (Bertin et al, 2022). In contrast, Holocene stratigraphic record along the intermontane valleys located at the eastern foothills of the Andes (200-300 km from the arc, Fig.…”

“…1a) of the Andes (14-28 • S) has been characterized by a prolific arc volcanism featuring hundreds of stratovolcanoes, collapse calderas, dome complexes, and mafic monogenetic centers (e.g., Trumbull et al, 2006;Kay y Coira 2009;Guzmán et al, 2014;Petrinovic et al, 2017;Wörner et al, 2018;Bertin et al, 2022Bertin et al, , 2023Báez et al, 2023). In the southernmost sector of the CVZ (23-28 • S), there are an estimated 30 to 40 volcanoes that are considered as potentially active (de Silva y Francis, 1991;Lara et al, 2011;Amigo et al, 2012;Elissondo et al, 2017;Aguilera et al, 2022;Bertin et al, 2022). These active arc and rear-arc volcanoes lay along the Chile-Argentina border, and most of them are far from populated urban centers.…”