An Interdisciplinary Approach Toward Improving Volcanic Threat Management
Managing the threat posed by hazards from an active volcano involves three components: understanding the volcano's past eruptive activity, assessing its present-day risk of eruption, and implementing the necessary actions to not only keep people safe, but informed and calm, during an eruption. My PhD research addresses these three goals through a combination of geologic observations, geophysical simulations, and analysis of volcanic hazards communications. My award-winning 3-minute Research Live! talk, which I gave back in my first year, provides a fun overview of the first two components of volcanic risk management. Meanwhile, my 2021 guest blog for "The Plainspoken Scientist" provides a glimpse of the third component, and what is was like for me, as a geoscientist, to venture into a completely new discipline--social science! In total, my thesis consists of four chapters: two based in geology and geophysics, and two based in communication science.
The first geology chapter of my thesis (available open-access via the Journal of Geophysical Research: Solid Earth) focuses on how stresses within New Zealand's now-extinct Akaroa volcano influenced the propagation and emplacement of a radial dike swarm around the volcano's erosional crater rim. I used field, satellite, seismic, and petrographic observations to define a finite element model (FEM) that numerically calculated the forces acting within the ancient volcanic system when it was active 9-8 Ma. These forces provide a map of where ancient magma blades, called dikes, plowed through the interior of Akaroa volcano before freezing near or erupting at its surface. This work provides evidence supporting one possible mechanism for Akaroa's crater rim dike swarm--the lateral deflection of vertically ascending dikes along a "stress barrier" formed by the competing forces of Akaroa volcano's weight and pressurization of its shallow magma source. This barrier may also explain the occurrence of flank, or downslope, eruptions on active volcanoes such as Italy's Mt. Etna or Hawaii's Kīlauea volcano. In fact, a series of flank eruptions occuring on Kīlauea in 2018 became Hawaii's largest eruption event in over two centuries! My second geology chapter (and fourth overall), currently in progress, will evaluate the global risk of flank eruptions from other active volcanoes using a combination of historic eruption records, ArcGIS data, statistical analyses, and the FEM developed in my first chapter.
Halfway through my PhD, I ventured into the realm of communication science to investigate how well in-person and online hazard communications, including those by the @USGSVolcanoes social media group, informed residents of Hawai‘i during the 2018 Kīlauea eruption. This work has resulted in two research manuscripts: one that has been published in the journal Volcanica, and another that is currently in revision with the journal Frontiers in Communication. The first of these projects focuses on in-person interview conversations I held in January 2020 with residents of the Island of Hawai‘i (a.k.a. the "Big Island"), where Kīlauea volcano is located, regarding their opinions of the communications they received over the course of the 2018 eruption. After using mixed social science methods to quantitatively and qualitatively interpret my notes from these semi-structured interview conversations, I found that residents from three distinct regions of Hawai‘i preferred communications from sources and messengers who were perceived to be most accesible and trustworthy among those communities. This result highlights the importance of building and maintaining close relationships between scientists/hazard managers and the communities they serve.
The second project related to volcanic hazard communication involved mixed qualitative and quantitative analyses of public communications between @USGSVolcanoes scientists and users of their Facebook page during the 2018 eruption. I investigated two overaching themes within these communications. The first theme focuses on the responsiveness of @USGSVolcanoes scientists and "informed" non-USGS users to other users' questions or occurrences of misinformation within users' comments. The second theme concerns emotions expressed in users' comments in response to eruption events, information provided by @USGSVolcanoes, and/or the comments of other users. From these two themes, I found that the @USGSVolcanoes Facebook page created a communication ecosystem that promoted factual information and contributed positively to users' overall emotional state. The dialogues between @USGSVolcanoes and their users provides a useful framework for improving real-time social media hazard communications between other science/hazard managment agencies and the communities they serve.
The first geology chapter of my thesis (available open-access via the Journal of Geophysical Research: Solid Earth) focuses on how stresses within New Zealand's now-extinct Akaroa volcano influenced the propagation and emplacement of a radial dike swarm around the volcano's erosional crater rim. I used field, satellite, seismic, and petrographic observations to define a finite element model (FEM) that numerically calculated the forces acting within the ancient volcanic system when it was active 9-8 Ma. These forces provide a map of where ancient magma blades, called dikes, plowed through the interior of Akaroa volcano before freezing near or erupting at its surface. This work provides evidence supporting one possible mechanism for Akaroa's crater rim dike swarm--the lateral deflection of vertically ascending dikes along a "stress barrier" formed by the competing forces of Akaroa volcano's weight and pressurization of its shallow magma source. This barrier may also explain the occurrence of flank, or downslope, eruptions on active volcanoes such as Italy's Mt. Etna or Hawaii's Kīlauea volcano. In fact, a series of flank eruptions occuring on Kīlauea in 2018 became Hawaii's largest eruption event in over two centuries! My second geology chapter (and fourth overall), currently in progress, will evaluate the global risk of flank eruptions from other active volcanoes using a combination of historic eruption records, ArcGIS data, statistical analyses, and the FEM developed in my first chapter.
Halfway through my PhD, I ventured into the realm of communication science to investigate how well in-person and online hazard communications, including those by the @USGSVolcanoes social media group, informed residents of Hawai‘i during the 2018 Kīlauea eruption. This work has resulted in two research manuscripts: one that has been published in the journal Volcanica, and another that is currently in revision with the journal Frontiers in Communication. The first of these projects focuses on in-person interview conversations I held in January 2020 with residents of the Island of Hawai‘i (a.k.a. the "Big Island"), where Kīlauea volcano is located, regarding their opinions of the communications they received over the course of the 2018 eruption. After using mixed social science methods to quantitatively and qualitatively interpret my notes from these semi-structured interview conversations, I found that residents from three distinct regions of Hawai‘i preferred communications from sources and messengers who were perceived to be most accesible and trustworthy among those communities. This result highlights the importance of building and maintaining close relationships between scientists/hazard managers and the communities they serve.
The second project related to volcanic hazard communication involved mixed qualitative and quantitative analyses of public communications between @USGSVolcanoes scientists and users of their Facebook page during the 2018 eruption. I investigated two overaching themes within these communications. The first theme focuses on the responsiveness of @USGSVolcanoes scientists and "informed" non-USGS users to other users' questions or occurrences of misinformation within users' comments. The second theme concerns emotions expressed in users' comments in response to eruption events, information provided by @USGSVolcanoes, and/or the comments of other users. From these two themes, I found that the @USGSVolcanoes Facebook page created a communication ecosystem that promoted factual information and contributed positively to users' overall emotional state. The dialogues between @USGSVolcanoes and their users provides a useful framework for improving real-time social media hazard communications between other science/hazard managment agencies and the communities they serve.
