Skip to content

What if? Quantifying exposure to high-impact low-probability eruptions

Elinor Meredith1, Heather Handley1,2, Susanna Jenkins3, Christopher Gregg4

  • Affiliations: 1ITC Faculty, University of Twente, Enschede, the Netherlands; 2School of Earth, Atmosphere and Environment, Monash University, Clayton, Australia; 3Earth Observatory of Singapore, Nanyang Technological University, Singapore; 4East Tennessee State University Department of Geosciences, Johnson City, USA 

  • Presentation type: Poster

  • Presentation time: Monday 16:30 - 18:30, Room Poster Hall

  • Poster Board Number: 12

  • Programme No: 6.1.18

  • Theme 6 > Session 1

Abstract

Due to their rarity and high mitigation costs, large-magnitude volcanic eruptions are often overlooked in disaster risk analysis and management in favour of more plausible events. However, population growth, technology dependency, and increased global system complexity would result in catastrophic impacts of such an eruption on a hemispherical to global scale. Identifying the potential scale and locations of hazards and impacts from large-magnitude volcanic events can help focus future research and target collaborative preparation efforts. Assessing exposure and potential impacts from these high-impact, low-probability events is challenging due to the lack of past event data, which makes forecasting difficult and introduces large uncertainties. Furthermore, to date, global exposure analysis methodologies typically consider distances up to 100 km from a volcano, even though past VEI 7 eruptions have deposited tephra beyond this distance. In this research, we propose a methodology to assess exposure to these large-scale eruptions. We assess exposure of populations, buildings, and infrastructure around likely candidate volcanoes for potential VEI 7 eruptions, with particular attention to those near waterbodies where tsunamis are likely to be triggered and those in tropical latitudes, which may have global climate implications. Using tephra fall isopachs from case studies of past VEI 7 eruptions, we calculate the probabilities of current and future exposure to tephra fall based on prevailing wind direction. We emphasise the sensitivity of tephra fall exposure to wind direction and isopach extent. Due to the high cross-border exposure, we highlight the need for international collaboration in preparing for such high-impact, low-probability events.