Graduate Thesis Or Dissertation
 

Using Magnetotellurics Towards Imaging the Primary Magma Reservoir in the Cotopaxi Volcano, Ecuador

Público Deposited

Contenido Descargable

Descargar PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/h415pj82t

Descriptions

Attribute NameValues
Creator
Abstract
  • In this study, 3D finite difference and 2D finite element forward modeling were used to create an electromagnetic sensitivity analysis for the Cotopaxi volcano in Ecuador. Magnetotellurics (MT) is a natural-source electromagnetic geophysical technique that images electrical conductivity. Measuring strong contrasts in electrical conductivity in volcanic materials allows for the interpretation and examination of the subsurface geologic structure and geochemistry of the internal system. Starting model conductor geometry is based on geophysical results from a 2019 gravity survey and magmatic fluids associated with the 2015 eruptive period were considered in these models. The smallest possible primary magma reservoir considered herein is a 6 km^3 conductor approximately 3 km beneath the subsurface. To determine the sensitivity of an Andean arc near surface magma reservoir to an MT survey, a dense array of stations separated by 1 km were centered over the conductor and nine periods were calculated to focus on the smallest target. In total, 7 starting models in 3D and 9 in 2D were assembled to consider how changes in shape along the horizontal plane as well as along the vertical axis influence the MT response. Analysis of impedance tensor components in 3D allowed for the electromagnetic dimensionality of the magma system to be determined for varying subsurface geometries of the reservoir. Surface level elevations and topography were added to the 2D models to understand the influence of topography on the apparent resistivity and phase results.
License
Resource Type
Fecha de Emisión
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Declaración de derechos
Publisher
Peer Reviewed
Language

Relaciones

Parents:

This work has no parents.

En Collection:

Elementos

Miniatura Título Fecha de subida Visibilidad Acciones
file details AngelKaitlanWE2023.pdf 2023-07-11 Público Descargar