Date of Award

2022

Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Geology (MS)

Administrative Home Department

Department of Geological and Mining Engineering and Sciences

Advisor 1

Simon A. Carn

Committee Member 1

Snehamoy Chatterjee

Committee Member 2

Greg Waite

Abstract

Over the past two decades, the availability of satellite measurements of volcanic gas emissions and heat flux has driven the development of new methodologies to improve global-scale volcano monitoring. In this work we explored the relationship between volcanic sulfur dioxide (SO2) emissions and radiant heat flux (RHF) measurements from NASA’s Ozone Monitoring Instrument (OMI) and Moderate Resolution Imaging Spectroradiometer (MODIS), respectively, to gain insight into how it associates to volcanic processes and eruption styles. The OMI SO2 emissions data are derived from existing databases developed by using the methodology in Fioletov et al. (2016), which contain global, passive volcanic SO2 degassing fluxes (PVF) for approximately 90-100 active volcanoes calculated at annual and seasonal intervals from 2005-2019 and 2005-2016, respectively. Volcanoes with available SO2 flux datasets and measurable MODIS RHF data were identified using the University of Hawaii’s near-time thermal monitoring of global hot-spots (MODVOLC) thermal alert system. The MODIS data was then integrated to match the annual and seasonal intervals at which the SO2 fluxes were calculated and converted from RHF to Volcanic Radiative Energy (VRE). Both parameters were analyzed quantitatively by building seasonal and annual timeseries and studying how they changed together. This successfully allowed us to see a variety of activity patterns, including but not limited to identifying endogenic and exogenic behavior and transitions between the two states in certain volcanoes. In addition, the VRE and SO2 annual and seasonal data was subjected to a simple linear regression analysis, through which we assessed the strength of the relationship given different types of activity, silica compositions and temporal scales. For example, we looked at six felsic dome/flow volcanoes with higher silica content products whose regressions using annual data returned a strong correlation that weakened when using their seasonally integrated data. Seven of the volcanoes with stronger correlations were used to extrapolate SO2 values from 2000-2005 (prior to the launch of the OMI satellite) based on 2000-2005 MODIS heat emissions data. Given the general lack of SO2 data for that period, it was not possible to corroborate the values and additional studies must be conducted to determine this method’s feasibility. Finally, we conducted an “excess” sulfur analysis where we quantitatively compared melt inclusion-derived sulfur content and total degassed sulfur estimates from 15 volcanoes which also returned high VRE-SO2 correlations. Our results show that there is no clear relationship between tectonic environments, magma composition or activity type (individually) and the amount of “excess” sulfur emitted by a volcano. Additional analyses are needed to determine if any specific combination between these could produce a higher correlation.

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Creative Commons Attribution-Share Alike 4.0 License
This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License.

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