Geophysics and Seismology Commons^™

Mapping Along-Strike Changes In Shallow Subduction Zone Geometry At The Alaska Subduction Zone Using Seismic Reflection And Tectono-Geomorphic Analysis, Madelyn K. Hurd

Earth and Planetary Sciences ETDs

The Alaska subduction zone, where the oceanic Pacific plate subducts beneath the continental North American plate at a rate of 60-66 mm/yr, has hosted more >M8 earthquakes over the last century than any other subduction zone globally. The largest of these, the 1964 M9.2 Alaska earthquake, ruptured 800 km of the margin, including a high slip patch near the trench offshore Kodiak Island. The 1964 rupture area may have overlapped with the 1938 M8.3 Semidi earthquake rupture zone that lies to the west. Slip propagation near the subduction trench during large earthquakes can control tsunamigenesis, and differences in wedge geometry …

Exploring The Role Of A Mushy, Crustal Compliant Region In Volcano Deformation, Grant A. Block

Physics & Astronomy ETDs

Volcanoes are both creative and destructive forces that have shaped and continue to shape our world from early geologic time to the present day. Continued study of volcanic processes not only better prepares us for monitoring volcanic hazards but also allows us to better understand processes fundamental to Earth as we know it, such as the generation of the atmosphere and accretion of the continents. This dissertation focuses on an integral part of volcanic processes: the trans-crustal magmatic transport system. Specifically, we investigate regions of these transport systems where magma pools in melt-rich lenses within broader regions of low melt-fraction, …

The Case For Ice Rises At Ross Bank Since The Middle Miocene, William Weber

LSU Master's Theses

Many tens of ice rises exist at the marine margins of the Antarctic Ice Sheet. Isle-type ice rises in particular are those where an ice shelf is pinned to an underlying submarine bank. Recent and ongoing studies show that Ross Bank, on the middle continental shelf of central Ross Sea, was the former site of an important Ross Ice Shelf ice rise during the advance and retreat of the West Antarctic Ice Sheet (WAIS) in the last glacial cycle. Ross Bank is a broad and anomalously shallow water platform whose crest rises to 170 m water depth. Despite their importance …

Somatic Prosthetics For Planetary Resonance, Disha Dharesh Kumar R

Masters Theses

This thesis investigates how industrial design can transcend extractive technological paradigms in favor of relational interfaces that foster planetary attunement. Framing the climate crisis as a 'crisis of imagination', the research challenges the Western bifurcation of nature and culture by drawing on Indic cosmologies- which recognize stones, plants, and ecosystems as conscious at different levels and participants in a shared cosmic field. By synthesizing research in Biosemiotics, Quantum Information Pansycishm, and Neuroscience, the project redefines intelligence as a distributed, more-than-human phenomenon.

The research materializes as a speculative design artifact: a device that functions as a somatic prosthetic for planetary resonance. …

Marine Geophysical Studies Of Coupled Tectonic And Sedimentary Processes At Active Plate Boundaries, Sarah R. Rysanek

Earth and Planetary Sciences ETDs

Deep-sea and convergent margin sedimentary systems preserve critical records of tectonic and climatic processes that shape Earth’s surface. This dissertation investigates source-to-sink sediment routing and forearc deformation to better constrain the interplay between sedimentary and tectonic processes, through investigations of a deep-sea fan system, and the forearc geomorphology offshore Nicaragua. In the Gulf of Alaska, we integrate ultra-long-offset and regional multi-channel seismic reflection data, multi-resolution bathymetry, and plate reconstructions to remap the Baranof Fan system. Results show that the fan is larger than previously recognized and constructed by two primary depocenters linked to distinct glacial sediment pathways, with accommodation space …

Phase Equilibria Modeling Constraints On Seismic Velocity And Density For Mafic Granulites In The Athabasca Granulite Terrane, Western Canadian Shield, Olivia Wyllie

Geosciences Undergraduate Honors Theses

Samples of mafic granulite and eclogite from the Athabasca granulite terrane, thought to be representative of the lower continental crust, were analyzed via bulk geochemistry analysis and seismically modelled with Perple_X v.7.1.6. Modeled P-wave speeds, S-wave speeds, and densities for the samples were graphed by region and calculated for wet (1.00 wt.% H2O) versus dry (0.01 wt.% H2O) conditions at 460 °C and 648 °C. The samples were found to have higher median P-wave values than those determined by Rudnick and Fountain (1995; 7.4 km/s to 7.8 km/s, as compared to 6.9 km/s to 7.2 km/s). This indicates both a …

Empirical-Based Model Of Spatio-Temporal Errors, Godwin Naaba Ndaa

Masters Theses

This research develops an empirical model to characterize spatial-temporal InSAR errors and improve the accuracy of deformation time-series analysis. Using standardized Sentinel-1 HyP3 products and MintPy, the study quantifies how correlated noise affects velocity precision and validates the results against continuous GNSS velocities.

Residual velocities are near-Gaussian, with σ ~0.92–2.04 cm/yr and ~1 cm/yr on average. Variograms show power-law spatial structure with a non-zero nugget implicating troposphere and decorrelation while errors drop exponentially with more acquisitions; spatial uncertainty is strongly affected by unwrapping errors, coherence, and tropospheric noise, not simply troposphere.

A comparative assessment of on-demand cloud processing with other …

Applied Machine Learning In Mineral Prospectivity Mapping In The South Pass-Granite Mountains Of Wyoming, Carl D. York

Graduate Theses/Dissertations

The South Pass-Granite Mountains, comprised of Archean to Tertiary rocks embedded with an Archean greenstone belt in Central Wyoming, have historically been mined for gold, iron, steel, and silver. Rare earth elements have been of increasing interest in the region and thus, several datasets have become available. Knowledge driven and data driven models are used in mineral prospectivity mapping with input data including geological mapping, geochemical data, geophysical (USGS Critical Mineral magnetic and gravity data), radiometric (U, Th, K) data and multispectral remote sensing data. Mineral prospectivity has seen a rapid improvement in recent years using advancements in machine learning …

Identification And Characterization Of Tornado Seismic Signals In The Central U.S., Seth Thompson

Theses and Dissertations--Earth and Environmental Sciences

Tornadoes cause extensive property damage and endanger lives. While Doppler radar can indicate the potential for tornado development, it cannot confirm that a tornado is in contact with the ground unless a debris signature is present. While on the ground, a significant amount of a tornado’s energy may be transferred into the earth as seismic vibrations. Thus, seismometers have the potential to detect on-the-ground tornadoes. Since 1960, only five papers have published seismic recordings from tornadoes. These studies have mostly reported on seismic waves generated by tornadoes at a relatively large range, from 0.01-2.5 Hz, representing uncertainty in the dominant …

Assessment Of Local Amplification Causes At Coastal Strong Motion Stations With Elevated Ground Motion Residuals From The 2024 Tewksbury, New Jersey Earthquake, Patrick Daniele

Open Access Master's Theses

Elevated ground motion amplitudes at individual stations are commonly observed in earthquake datasets, yet the physical causes of these residuals are often not explicitly identified. This study investigates two seismic monitoring stations in southeastern New York that recorded amplified motions during the 2024 Mw 4.8 Tewksbury, New Jersey earthquake. A consistent set of established geophysical methods -- including multichannel analysis of surface waves (MASW), passive ambient noise arrays (MAM), stochastic inversion, horizontal-to-vertical spectral ratio (HVSR) analysis, and directional spectral ratio techniques -- was applied to directly characterize site conditions and identify the mechanisms contributing to amplification.

Results show that elevated …

Bridging The Gap: Evaluating Gnss-Derived Total Water Storage As A Groundwater Monitoring Tool In The Colorado River Basin, Michelle Lee Barton

Graduate Student Theses, Dissertations, & Professional Papers

Groundwater resources in the Colorado River Basin are critically stressed yet remain under-monitored and under-regulated, creating urgent need for reliable, continuous observations at multiple spatial scales. This study evaluates the performance of the University of Montana Global Navigation Satellite Systems (GNSS) terrestrial water storage dataset as a tool for bridging groundwater monitoring gaps across the Upper and Lower Colorado River Basins between 2006 and 2024. We compare GNSS-derived total water storage and groundwater storage estimates against NASA’s Gravity Recovery and Climate Experiment (GRACE) satellite observations and in-situ groundwater well measurements at regional and sub-regional scales. We employ a Bayesian autoregressive …

Towards Spatial Inversion Of Aerial Gamma-Ray Survey Data For Measurement Of Naturally Occurring Radioactivity, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma-ray surveying (AGRS) is used in geologic and environmental contexts to provide data on the surface spatial distribution of naturally occurring radioactive material (NORM) or other gamma-ray-emitting isotopes. The standard data reduction workflow for AGRS data involves a process whereby pointwise gamma-ray spectral data are denoised, corrected for numerous sources of background radiation and aircraft height, and are finally converted to physical values by empirical conversion factors. The reduced pointwise data are then typically spatially interpolated to form a continuous surface map.

This dissertation introduces and explores a novel spatial inversion method for reduced AGRS data that considers aircraft …

First-Principles Insights Into Binary Oxide Systems Under Extreme Pressure, Daniel Schacher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pressure is powerful tool by which one can manipulate the properties of materials. In this work we utilize pressure to explore binary oxide systems and characterize their structural and electronic properties. The observation of anomalous structural and electronic behavior in the rutile to CaCl2 phase transition in SnO2 led to the prediction that such behavior is inherent to all oxides experiencing such a phase transition sequence.[1] Here, the ultra-wide band gap semiconductor GeO2 is confirmed to exhibit anomalous behavior during the rutile to CaCl2 phase transition. A phase pure rutile GeO2 sample synthesized under high-pressure, high-temperature, conditions is probed using …

Seismological Investigations Of Magmatic Systems Using Dense Nodal Arrays, Wenkai Song

Earth and Planetary Sciences ETDs

Understanding the internal architecture of magmatic systems is crucial for volcanology, yet conventional geophysical techniques often lack the resolution to image their fine-scale structures. This dissertation leverages unique datasets from dense nodal arrays to investigate the upper crustal magmatic systems beneath Yellowstone Caldera, Valles Caldera, and Mount St. Helens. At Yellowstone, I processed vibroseis data to delineate the top of the modern magma reservoir and evaluate the thermal connection between the magmatic and the overlying hydrothermal systems. At Valles, 3D radial seismic anisotropy imaging reveals strong positive radial anisotropy within the reservoir, indicating an organized structure of horizontally sill-like melt …

A Kinematic, Data-Parameterized Approach To Constrain Subducted Seafloor During The Emplacement Of Shatsky Rise, Alexzandrya Katrina Shotorban

OES Theses and Dissertations

This study investigates ridge spreading rates and plate boundary geometry in interactions between large igneous provinces and mid ocean ridges, and their role in the kinematics of Shatsky Rise, an undersea volcanic plateau in the western Pacific Ocean that is roughly the size of the state of California. Shatsky Rise formed at a ridge-ridge-ridge (RRR) triple junction (TJ) (Hilde et al., 1976; Sager et al., 1988), at the intersection of the Pacific-Izanagi, Pacific-Farallon, and Izanagi-Farallon ridges, beginning at approximately 147 Ma. Investigations into Shatsky Rise’s formation are limited by the fact that two-thirds of the seafloor data has subducted with …

Integrating Satellite Observations And Modeling Approaches To Study Tectonic And Land Surface Hazards, Jeng Hann Chong

Earth and Planetary Sciences ETDs

The increasing availability of Earth observation satellites, such as SAR and optical platforms, has improved our ability to study the ground deformation processes during, after, and leading up to these natural hazards, such as earthquakes and debris flows. In this dissertation, I analyze satellite geodetic interseismic velocities across the Rakhine-Bangladesh megathrust and the influence of having realistic modeling assumptions for subduction zones to better constrain seismic hazard. I also examined changes in post-fire debris flow likelihood four years after the 2020 Lake Fire in Southern California using a suite of satellite data and field observations. Together, these studies highlight how …

The Compositional And Dynamical Properties Of Exoplanets, Cody James Shakespeare

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solid surface density profile of protoplanetary discs, and the composition of these solids, can be formed through sequential condensation models of dust precipitating from the cooling gas of the solar nebula. I continue developing a code that reproduces the chemical compositions of most chondrites as well as the bulk compositions of the rocky planets using our partial condensation model with an evolving disc. I extend this validated code to exoplanet systems with different initial elemental ratios, like the carbon-to-oxygen ratio and estimated stellar abundances over the age of the universe. I have improved this dust condensation code to include …

High-Frequency Seismic Noise In Desert Environments, Alexis Hernandez

Open Access Theses & Dissertations

This study investigates the generation and modulation of ambient seismic noise in arid environments, with a focus on aeolian processes such as saltation, wind shear, and precipitation events. Using a dense array of three-component seismic nodes co-located with meteorological sensors and a novel particle transport instrument (SANTRI), high-frequency seismic signatures were examined within the Jornada Experimental Range in southern New Mexico. Time-frequency analysis reveals that wind-driven saltation events produce measurable seismic energy enhancements, particularly within the 100-300 Hz band, with clear spectral distinctions between wind-only forcing and particle-laden transport. Additionally, rainfall events were identified by elevated seismic amplitudes in the …

Magnetic Reconnection In Space: From Two-Dimensional Magnetohydrodynamic (Mhd) Simulations To Three-Dimensional Particle-In-Cell (Pic) Simulations, Shan-Chang Lin

Dartmouth College Ph.D Dissertations

Magnetic reconnection is a physical process in plasmas that converts magnetic energy into plasma kinetic energy and thermal energy. It plays an important role in the generation of solar flares, interactions between the solar wind and Earth's magnetosphere, and magnetic confinement fusion devices. This thesis focuses on studying magnetic reconnection using computational methods, including two-dimensional (2D) magnetohydrodynamics (MHD) simulations to study Petschek-type reconnection, estimating the timescale from a thin current sheet to fully developed reconnection using 2D particle-in-cell (PIC) simulations, and magnetic reconnection X-line spreading in the current direction using three-dimensional (3D) PIC simulations.

This thesis contributes to the understanding …

Seeking Structure In Complex Systems: From Feature Analysis To Space-Time Causal Discovery With Earth Science Applications, Jeffrey J. Nichol

Computer Science ETDs

Complex systems are difficult to study because of their many interacting parts, emergent phenomena, and feedback loops. These systems underpin all life on Earth. We need improved tools for seeking an understanding of them. This body of research presents my investigations into data-driven methods for understanding complex systems, including my invention of a novel causal discovery meta-algorithm for space-time gridded data. I demonstrated machine learning feature importance and causal discovery capabilities for comparing simulated and observed climate data. I developed a new benchmark for modeling space-time dynamics of locally driven phenomena and examined a prominent causal discovery algorithm. Finding that …

The Surface Water And Ocean Topography (Swot) Mission For River And Lake Ice Application, Sunwoo Yoon

Earth Sciences Theses and Dissertations

The Surface Water and Ocean Topography (SWOT) mission, launched in December 2022, is designed for global survey of Earth’s surface water. However, the seasonal freezing of lakes and rivers combined with SWOT’s unique interferometric radar characteristics presents a valuable opportunity to assess its potential for river and lake ice applications. In this dissertation, I first compare backscatter characteristics over open water and frozen lakes and rivers. I demonstrate strong contrast in backscatter between water and ice while accounting for incidence angle, highlighting SWOT’s capability to discriminate between surface cover types. However, overlapping backscatter signatures suggest further investigation of drivers of …

Characterization Of The Quaternary Active Twin Lakes Fault, Mount Hood, Oregon, Johnathan Peterson

University Honors Theses

The High Cascades chain of volcanoes results from Cascade Arc volcanism and is responsible for the generation of the highest topography in the state of Oregon. Surrounding Mt. Hood at the crest of the Cascade chain in northern Oregon is the Mt. Hood Fault Zone, an extensional fault zone of generally north-south trending normal faults that down-drop this high volcanic topography. The Twin Lakes Fault is located just south of Mt. Hood and is one of the southernmost faults in the Mt. Hood Fault Zone, previously mapped as approximately 12-13 km in length. This study provides the first in-depth characterization …

Calculating Moment Magnitude Using The Coda Calibration Technique To Update The Earthquake Catalog Of Iraq (1900-2021), Muntadher Al-Kaabi

Theses and Dissertations

The first comprehensive earthquake catalog for Iraq based on moment magnitude (Mw) ‎was compiled by Onur et al. (2017). It spanned the period from 1900 until the end of ‎‎2009, covered the region between 26°–40° N latitudes and 36°–51° E longitudes, and ‎included more than 18,000 earthquakes, of which roughly 4,000 are of Mw 4.0 or larger. ‎With the ongoing efforts of updating the probabilistic seismic hazard assessment ‎‎(PSHA) and the Iraqi building code, the need for an updated earthquake catalog for Iraq ‎in terms of moment magnitude (Mw) has been raised. Robust estimation of moment ‎magnitude (Mw) can be …

Seismological Applications To Crustal Deformation And Explosion Discrimination, Olumide Adedeji

Earth and Planetary Sciences ETDs

There are many outstanding questions in seismology and plate tectonics that remain unresolved due to the complexity of seismic wave propagation, fault system evolution, and sedimentary-tectonic interactions. In this dissertation, I analyze seismic and acoustic data to improve event discrimination, understand strain partitioning along a transpressive plate boundary, and investigate the influence of tectonic deformation on sedimentary processes. Using seismic arrays, I assess the detectability of Ground Coupled Airwaves (GCA) generated by shallow borehole explosions and earthquakes, demonstrating that GCA detections are highly dependent on source type, environmental conditions and sensor distribution. Along the Queen Charlotte Plate Boundary, I analyze …

Survey Of A Paired Gravity Anomaly Within The Benton Uplift Of The Ouachita Mountains, Isaac B. Prud'homme

Physics Undergraduate Honors Theses

The Benton Uplift west of Hot Springs, AR is underlain by a paired gravity anomaly on the order of 80 mGal. Nicholas & Rozendal (1975) have theorized that the gravitational low is caused by a “downwarp of the crust into the mantle”1 however the cause of the gravitational high is still debated. This paired gravity anomaly within the Benton Uplift follows the Ouachita orogenic belt southwest for 500 miles where it meets the Marathon uplift in southwest Texas. We conducted a gravity survey along a 108-km-long transect east of two previous gravity surveys.2,3 We corrected the data from this transect …

Improved Snow Distribution Estimates Using A Rapid-Response Lidar And Photogrammetry System, Naheem Idowu Adebisi

Boise State University Theses and Dissertations

Snow plays a critical role in global hydrology, climate systems, and human activities, particularly in mountainous regions where it is a primary source of freshwater, influences the energy balance, and impacts mobility and commerce. Despite its importance, accurately mapping and predicting snow distribution remains a major challenge due to the complex spatial and temporal variability of snowpack and the lack of an ideal observation system. This dissertation aims to advance our monitoring capability, understanding, and prediction capacity of snow distribution using Light Detection and Ranging (LiDAR) and photogrammetry techniques.

In chapter 2, I discussed the high-resolution LiDAR-derived datasets of multiple …

Resilience Webtool: Engaging Community Partners To Humanize Data For Use In Local Resilience Planning In Valley County, Idaho, Sabrina Akther

Boise State University Theses and Dissertations

Advancements in technology have made hazard data increasingly available. However, officials in rural communities with limited resources often face challenges in accessing, interpreting, and applying these data to assess vulnerabilities and plan future development. Furthermore, when hazard data is not paired with relevant population and infrastructure, data vulnerability assessments become increasingly difficult. To address this challenge, this project aims to co-create a web tool with decision makers in Valley County, Idaho following a user-centered design approach, consolidating hazards, social vulnerability, and infrastructure data to help local officials with risk management, decision-making, and resilience planning. The project started with listening sessions, …

Inter-Hemispheric Asymmetry In The High-Latitude Electrodynamics And Their Impacts On The Magnetosphere-Ionosphere-Thermosphere System, Yu Hong

Physics Dissertations - Archive

In this dissertation, the inter-hemispheric asymmetries (IHAs) in the ionosphere–thermosphere (I-T) system and their impacts on the coupled magnetosphere-ionosphere–thermosphere (M-I-T) were examined using multi-instrument observations and advanced global numerical modeling frameworks. First, the drivers and consequences of IHAs in the I-T were systematically investigated and quantified, revealing that seasonal solar irradiance differences, geomagnetic field offsets, and asymmetric high-latitude electrodynamic forcing each produce significant asymmetries in electron density, neutral density, velocity, and Joule heating, with seasonal effects dominating under relative quiet conditions. During geomagnetic storms, IHAs were found to depend more strongly on asymmetric field-aligned currents (FACs) and particle precipitation (PP), …

Sedimentary Archives Of Late Quaternary Limnological, Ecological, And Environmental Change In The Eastern Sierra Nevada (California, Usa), Bailee Hodelka

Theses and Dissertations--Earth and Environmental Sciences

The Sierra Nevada essentially serve as the headwaters of California, providing crucial freshwater to the state through seasonal snowmelt. This water supply is threatened by climate change in complex ways that are not fully understood. Geological records provide a valuable source of information on how the hydrology, limnology, and ecology of the Sierra Nevada region has responded to climate changes of the past. This dissertation presents new sedimentary and paleoecological research from Mono Lake and Convict Lake (Mono County, California) and aims to shed light on environmental changes in the eastern Sierra Nevada from ~16 ka to present.

At Mono …

Evaluating Tropospheric Delay Modeling For Enhanced Geospatial Accuracy, Adeyinka Olaoluwa Olaseinde

Masters Theses

Interferometric Synthetic Aperture Radar (InSAR) is a vital technique for monitoring ground surface deformation across large spatial scales. However, variability in atmospheric water vapor, pressure, and temperature introduces tropospheric delays that can significantly affect measurement accuracy. These delays are often corrected using outputs from numerical weather prediction (NWP) models. RAiDER, an open-source Python package, facilitates this by estimating tropospheric delays using models such as the High-Resolution Rapid Refresh (HRRR). Previous studies have shown that weather model–based corrections can substantially reduce atmospheric noise in InSAR data but also highlight persistent residual errors, especially at spatial scales smaller than the model grid …