An interdisciplinary approach toward improving volcanic flank eruption threat assessment and hazard communication

Mitigating the threat that an active volcano poses to surrounding communities involves several components: understanding the volcano's past eruptive activity, assessing its present-day eruption threat, and implementing the necessary actions to keep people safe, informed, and calm during an eruption. This doctoral dissertation addresses these goals in four main chapters that provide complementary Earth and social science methodologies to better understand how volcanic flank eruptions occur and best practices for communicating their associated hazards and threats to local and global audiences. The dissertation is organized as follows. Chapter 1 provides an overview of the significance, findings, and implications of each of the four research chapters. Chapter 2 addresses how stress evolution of New Zealand's now-extinct Akaroa Volcano may have facilitated the emplacement of dikes exposed radially along its flanks. Present-day geologic and geophysical observations of Akaroa were applied to a finite element model simulating the volcano's paleo-stress field to test how different factors may have promoted or inhibited dike propagation along Akaroa's flanks (published as Goldman et al., 2022) . In Chapters 3-4, complementary qualitative and quantitative analyses were conducted of the communication response by the United States Geological Survey (USGS) Volcano Hazards Program, the USGS Hawaiian Volcano Observatory, and the official social media group USGS Volcanoes during the historic 2018 flank eruption and summit collapse of Kīlauea Volcano. These analyses show that USGS volcanic hazard communicators were most successful when they engaged their audiences through positive or empathic messaging that included the prompt and direct delivery of accurate eruption information. Chapter 3 is published as Goldman et al. (2023) and Chapter 4 is currently in press with Frontiers in Communication. Chapter 5 consists of a global hazard and threat assessment of historic flank eruptions using the Smithsonian Institution's Global Volcanism Program database. Comparisons between this assessment and those of previous regional and global volcanic threat studies demonstrate that the evaluated hazardousness of flank-erupting volcanoes relative to non-flank-erupting volcanoes depends greatly on 1) how individual hazards from each volcano are weighted in formulas for calculating overall hazardousness, and 2) whether or not the cumulative duration of eruptions occurring from each volcano are factored into calculations of their hazardousness. A key lesson learned through conducting these four methodologically distinct investigations of flank eruption mechanics, hazards, and science communication is the interdependency of geology and communication science for preparing human populations for present and future volcanic threats.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Geology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Goldman, Robert Trevor

Contributors dc:contributor

• Gregg, Patricia M
• Stovall, Wendy K
• Wood, Gillen D
• Maguire, Ross R

• Flank Eruption
• Hazard Communication
• Threat Assessment
• Akaroa
• Kilauea
• Trust
• Messenger
• Social Media

Statement dc:rights

• Copyright 2023 Robert T. Goldman

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/121473

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F121473