The migration of magma within a volcano produces a deformation signature at the Earth's surface. The location, shape, and pressurization of the magma chamber, as well as the internal structure of the rocks surrounding the magma chamber, control the specific deformation pattern that can be observed at the surface of the volcano. Quantifying the characteristics of magma migration is important, because the upward migration of magma is a precursor to volcanic eruptions. This project will develop finite element models (FEMs), a type of numerical method, to simulate volcanoes as a dynamic system that accounts for the interaction of migrating magma within the complex internal structure of an active volcano. These FEMs will be used in inverse methods that seek to quantify estimates and uncertainties of a few characteristic parameters that describe magma migration into, or out of, a magma chamber. These methods will be developed in the context of two volcanoes (Okmok, Alaska, and Tungurahua, Ecuador) that will serve as natural laboratories. Both of these active volcanoes have known internal structures in the form of tomography models estimated using data from ground-based seismic instruments, as well as surface deformation histories that were recorded with geodetic data (e.g., GPS data and satellite radar imagery) over the past decade. More specifically, this project will use FEM-based inverse analyses of geodetic data to determine estimates and uncertainties for the location, shape, and pressurization of magma chambers embedded in the complex internal structures of these two active volcanoes. More generally, this project will develop methods to integrate volcano geodesy and seismology, two traditionally disparate geophysical fields of study. This integration is poised to advance the fundamental understanding of active volcanoes.
This project comprises collaborative research among early-career and mid-career faculty and graduate education at the South Dakota School of Mines and Technology (SDSMT), an EPSCoR institution. SDSMT is a regional center for science and engineering research and is ideally located to interface with a substantial local Native American community. The proposed methods will provide powerful numerical techniques to combine different types of information that are customarily used independently from one another to assess volcano hazards. This ability to simultaneously analyze different types of information will provide a more complete picture of the internal processes for a given active volcano and will likely lead to more reliable predictions of volcanic behavior. The methods developed by this project will be designed to be generally amenable for other analyses of volcano deformation and ultimately provide important societal benefits of more reliable natural hazards assessments. Another impact of this project is its direct relevance to studies of earthquake deformation, which are driven by analogous configurations of deformation sources embedded in complex structures associated with active faults. Thus, the techniques developed for this project may be readily extended to studies of earthquake deformation and may have important implications for future analyses of seismic and tsunami hazards worldwide.
