Tephra clean-up after the 2015 eruption of Calbuco volcano, Chile: a quantitative geospatial assessment in four communities

STEWART, CAROL; BEIGT, DÉBORA; LEONARD, GRAHAM S.; HAYES, JOSH L.; VILLAROSA, GUSTAVO; OUTES, VALERIA; WILSON, THOMAS M.; SALGADO, PABLO; DELIGNE, NATALIA I.

Journal of Applied Volcanology

BMC Part of Springer Nature

Lugar: Heidelberg; Año: 2019 vol. 8 p. 1 - 23

Reliable methods for volcanic impact and risk assessments are essential. They provide constructive information toemergency and disaster managers, critical infrastructure providers, the insurance industry, and wider society. Posteruptionclean-up of tephra deposits is a prevalent and expensive (time and resource) activity which is often notplanned for. Here, we present an overview of the clean-up efforts undertaken in four communities after the VEI 4eruption of Calbuco volcano in 2015. We narratively reconstruct clean-up efforts in Ensenada (Chile), Junín de losAndes (Argentina), San Martín de los Andes (Argentina), and Villa La Angostura (Argentina) using semi-structuredinterviews, syn- and post-deposition photographs, pre- and post-event visual spectrum satellite imagery, and mediareports. We compare these reconstructions with estimates based on a geospatial modelling approach adapted fromHayes et al. (Journal of Applied Volcanology 6:1; 2017). Specifically, we compare reported and geospatially derivedestimates for volume of tephra removed, and clean-up operation duration. Our modelling approach performed well forJunín de los Andes but did not adequately capture volume and clean-up operation duration for the three remainingcase study locations. We discuss several sources of uncertainty (including observational errors and natural variance oftephra deposit thickness), reported tephra removal volume estimates, clean-up methods, land use, and temporalevolution of clean-up operation demand. Our work demonstrates the utility of using simple geospatial data to developassessments for tephra clean-up for use in response and recovery planning, and quantitative volcanic impact and riskassessments.