Date of Award

Fall 2020

Project Type

Thesis

Program or Major

Earth Sciences

Degree Name

Master of Science

First Advisor

Julia G Bryce

Second Advisor

Sarah A Miller

Abstract

The Aleutian volcanic arc in southwest Alaska is known for active volcanoes that can significantly interfere with air traffic. Outstanding questions in the Aleutians, as in most active volcanic regions, include both the indications of an imminent eruption and the evolution of magma within the volcanic system. Remotely sensed observations, such as seismic activity, gravity and thermal anomalies, and gas and ash emissions, may be used in conjunction with geochemical studies of volcanic crystals to improve estimates of the pacing of eruption, thereby enhancing the capability to connect magmatic processes with observed surficial expressions. The objectives of this work are 1) to create volcanic activity timelines produced from the compilation of remotely sensed data across multiple platforms, 2) evaluate the pacing of magma accumulation through the elemental diffusion within volcanic minerals, and 3) compare the two timeline reconstructions to relate aboveground indications of volcanic activity to belowground magmatic processes. I will make progress on these objectives by constructing timescales of volcanic activity as observed in vast datasets of spectral, gravitational and thermal measurements collected from satellites (MODIS, GRACE, ASTER) and other remote sensing sources. Remote sensing timescales will be compared to timescales reconstructed from records of isotopic and elemental distribution within volcanic crystals, namely plagioclase and pyroxene, from the 2006 Augustine eruptions. Variations in the composition of crystals serve as a record of the change of magma chamber conditions during crystal growth. The overall goal in syncing geochemical models with remote sensing data is to understand the symptoms of the underlying magmatic process that are expressed on the surface to enhance eruption prediction and to constrain timescales produced by the magma modeling. By relating timescales produced from differing datasets, I aim to introduce a new assessment of volcanic arc magma systems and ultimately to improve the ability to forecast eruptions.

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