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 doctoral dissertation addresses these three goals through a combination of geologic observations, geophysical simulations, and analysis of volcanic hazards communications.
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 Ph.D. research chapter) evaluates 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 Hawaii during the 2018 Kīlauea eruption. Accordingly, the second research chapter of my thesis (and published open-access in the journal Volcanica) 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 and the communities they serve.
My second Ph.D. project related to volcanic hazard communication (and third research chapter overall, published open-access in the journal Frontiers in 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 communications between other hazard-monitoring agencies and the communities they serve.
Additional information regarding my research, professional, and outreach experiences is provided in my CV, below:
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 Ph.D. research chapter) evaluates 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 Hawaii during the 2018 Kīlauea eruption. Accordingly, the second research chapter of my thesis (and published open-access in the journal Volcanica) 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 and the communities they serve.
My second Ph.D. project related to volcanic hazard communication (and third research chapter overall, published open-access in the journal Frontiers in 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 communications between other hazard-monitoring agencies and the communities they serve.
Additional information regarding my research, professional, and outreach experiences is provided in my CV, below:
| rgoldman_cv_apr2026.pdf |
