Forecasting volcanic unrest through geodetic data assimilation

Volcanic eruptions pose a serious hazard to communities around the world, and one of the key goals of volcanology as a discipline is to better forecast volcanic unrest so that the damage and loss of life caused by future events can be minimized. To that end, many active volcanoes host extensive monitoring networks, both ground-based and spaceborne, that detect deviations from the system’s baseline behavior. This dissertation focuses on using the Ensemble Kalman Filter (EnKF), an advanced data assimilation technique, to derive the physical conditions of an active magma reservoir from geodetic measurements of ground deformation. The models produced by the EnKF can in turn be used to measure the stress state in and around the reservoir, determining its long-term mechanical stability and the likelihood of a physically triggered eruption. After successfully applying this framework to hind-cast the 2008 eruption of Okmok, Alaska, I use a series of synthetic tests to measure the EnKF’s sensitivity to different drivers of magmatic inflation. While changes in different reservoir parameters can produce very similar geodetic signals, the EnKF can broadly distinguish between different scenarios, albeit with some difficulty resolving exact reservoir parameters. By evaluating the performance of different variations on the EnKF workflow, I show that these distortions are persistent and arise from non-uniqueness in the geodetic observations. Although the application of geodetic data can only constrain a magma reservoir to within a range of non-unique states, that range is narrow enough to provide meaningful information about the system’s stability. In the end, I show that the EnKF can quickly and efficiently invert geodetic data, particularly high-resolution satellite measurements, to provide useful eruption forecasts.

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

2022

Author dc:creator

• Albright, Jack

Contributors dc:contributor

• Gregg, Patricia M
• Liu, Lijun
• Best, James
• Marshak, Stephen
• Pettijohn, Justin C

• geodesy
• EnKF
• geodynamics
• eruption forecasting

Statement dc:rights

• Copyright 2022 Jack Albright

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/116212

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F116212