Earth Sciences Commons^™

Reading The Martian Surface: Impact Crater Distributions And Geochemical Signatures In Gale Crater As Recorded By The Curiosity Rover, Megan E. Hoffman

Earth and Planetary Sciences ETDs

The Curiosity rover has been exploring Gale crater, a large impact basin near the Mars equator since 2012. This mission has greatly improved our ability to explore the surface of Mars with a suite of geologic tools and cameras and has revealed that Mars likely once resembled present-day Earth. In this dissertation, I utilize measurements and data taken by Curiosity to analyze the distribution and preservation of small impact craters at meter scales, I quantify the formation characteristics of a small impact crater cluster, and I examine the presence of barium in a geologic unit with high-Si to constrain sediment …

Pebble Accretion: Compositions And Water Origins Of Terrestrial Planets, Susmita Garai

Earth and Planetary Sciences ETDs

Two leading models of planet formation invoke either stochastic collisions among km-sized planetesimals, or pebble accretion of sub-mm-cm solids regulated by gas drag. While collision based models typically require tens to hundreds of millions of years to assemble terrestrial planets, pebble accretion can produce Mars to Jupiter-mass bodies within the lifetime of the protoplanetary disk. Although widely accepted for the rapid growth of giant planet cores, the role of pebble accretion in forming terrestrial planets, including Earth, remains debated. Here, we investigate the consequences of pebble accretion for Earth’s origin. Here, I combine numerical models and laboratory experiments to find …

Mining Legacy And Wildfires: Interfacial Reactions Affecting Metal Mobility, Eresay Alcantar-Velasquez

Earth and Planetary Sciences ETDs

We identified water labile interfacial reactions between laboratory burned pinewood ash and mine waste solids that influence metal mobilization. The Upper Gallinas Creek Watershed in New Mexico is affected by wildfires and mining legacy. Pinewood and mine waste sediments were sampled from the area, and the pinewood was burned at 350°C to simulate medium burn intensity ignition. Rapid desorption and gradual dissolution of Mn and Fe was detected by ICP-MS as pH decreased over time. After reacting 18 MΩ ultra-pure water with a mixture of pinewood ash and mine waste sediments Fe (143%) and Mn (89.2%) concentrations increased over time. …

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 …

Information Theory Analysis Of Water Vapor Stable Isotopes From The Sail Campaign, Matthew John Rybecky

Earth and Planetary Sciences ETDs

Understanding the processes that control water vapor isotopic composition in mountain environ- ments is essential for interpreting isotope records and predicting water resource responses to cli- mate change. This thesis applies information theory to continuous, high-resolution water vapor stable isotope measurements from the Surface Atmosphere Integrated Field Laboratory (SAIL) campaign in the East River watershed of Colorado’s Upper Gunnison Basin, spanning the winter- to-spring transition of 2022–2023. The analysis employs Shannon entropy, mutual information, transfer entropy, and joint transfer en- tropy (JTE) to quantify how environmental variables, including surface meteorology, radiation, tur- bulent fluxes, and ERA5 reanalysis products, transfer information …

Quantifying Co2 And Ch4 Fluxes In A Semi-Arid Floodplain: Assessing Spatial And Temporal Drivers, Miles E. Kelsey

Earth and Planetary Sciences ETDs

Rivers transport sediment and carbon across Earth’s surface, and their floodplains can store carbon over decades to millennia, making them important to terrestrial carbon management. While soil carbon can persist long term, it may be released as greenhouse gases through processes like methanogenesis and heterotrophic respiration. Environmental controls on these fluxes remain poorly constrained across floodplains in different climate and geomorphic setting, but especially in semi-arid systems where measurements are limited. To address this gap, we quantified CO₂ and CH₄ fluxes along the Middle Rio Grande (New Mexico, USA) using 227 chamber measurements collected May to November 2025 at three …

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 …

Constraining Magmatic Processes In The Central American Arc Using Melt Inclusion Vapor Bubble Analysis And Triple Oxygen Isotope Modeling And Exploration Of Volatile Contributions To The Production Of Continual Radio Frequency (Crf) Lightning Events, John M. Hamilton

Earth and Planetary Sciences ETDs

Magmatic volatiles are key to determining the processes happening in the subsurface that we cannot directly sample. Advances in measuring volatile and isotope contents from erupted volcanic samples have given us the ability to understand magmatic processes, mixing components that produce the bulk magma composition and potentially precursors to eruptive hazards, such as lightning.

Through analysis of melt inclusions that sample the melt at depth and triple oxygen isotope quantification of olivine crystals from multiple volcanic edifices, the three following studies display how I have utilized these analytical techniques to help unravel processes happening in the subsurface that lead volcanic …

Dense Temporary Array Investigation Of Jemez Uplift Seismicity, Jillian D. Podmore

Earth and Planetary Sciences ETDs

A protracted multi-stage tectonic and magmatic evolution combined with low regional crustal strain rates make it challenging to characterize active structure that may host earthquakes in the Jemez Mountains of New Mexico. Here, we leverage temporary 1-month deployments of nodal seismometers to gain new insights into seismicity of the Jemez Mountains, which only have continuous seismic monitoring on their eastern flank as a result of the Los Alamos Seismic Network. Our catalog is built using 4 steps: phase picking in continuous seismic data, association of picks to detect unique events, event magnitude estimation, and absolute hypocenter estimation. We detect and …

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 …

Contemporary Martian Geomorphic Processes And The Suitability Characterization Of Terrestrial Analogues, Daniel Paul Mason

Earth and Planetary Sciences ETDs

Both historical and contemporary evidence for geomorphic activity on the surface of Mars is apparent. This evidence is showcased by features including a) well-preserved deltaic remnants in an otherwise cold and arid environment, present along the western flank of Jezero Crater, and b) the seasonal appearance of candidate recurring slope lineae throughout Martian equatorial, lower, and mid-latitudes as seen within both the Eos Chasma region and on the walls of Raga, Lohse, Rauna, and Tivat Craters. In this dissertation, I elucidate the role that geomorphic processes, whether aqueous or dry, have played in shaping both the ancient and contemporary Martian …

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 …

Using Triple Oxygen Isotopes To Investigate Water Usage In Desert Ecosystems, Cloe V. Knutson

Earth and Planetary Sciences ETDs

In arid environments, maintaining water balance can be more critical for survival than obtaining food. As droughts intensify, understanding how animals manage body water is essential. Triple oxygen isotope analysis provides a novel way to trace water sources in animals, distinguishing contributions from free water, food-derived oxygen, and atmospheric O₂. We developed an equilibration method using CO₂–H₂O oxygen exchange and measured δ^’18O and Δ^’17O values via tunable infrared laser direct spectroscopy (TILDAS). Validated against traditional fluorination methods, this technique enables streamlined analysis of whole blood and plant samples. Applied to …

Modeling Mars Chaos Terrains As Fracture Mosaics, Aidan C. Buie

Earth and Planetary Sciences ETDs

Chaos terrain exists on several planetary bodies but most notably on Mars. With 30 different named terrains and hundreds of chaotic or ”chaos-like” terrains, they are one of the most prominent and visible features on the planet. Chaos terrains have many visible similarities to each other: they all are comprised of polygonal blocks separated by fractures or channels. These blocks vary from angular to rounded and from flat plateaus to small hills, and the fractures vary from flat floored to ”v” shaped. Often, a single chaos will contain all of these morphologies. Most of the 30 named chaoses on Mars …

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 …

Insights Into Fluid-Rock Interactions On The Cv3 Chondrite Parent Body Through The Use Of Secondary Garnets In The Allende Cv3 Chondrite And Terrestrial Skarns, Jessica Marie Johnson

Earth and Planetary Sciences ETDs

Garnets are valuable for studying geologic processes, particularly fluid-rock interactions in terrestrial skarns. This dissertation examines secondary garnets and associated Ca-Fe silicates in Allende-like CV3 chondrites and terrestrial skarns to assess garnets as recorders of fluid-rock interactions. Chapter 2 investigates garnets from the Willsboro-Lewis skarn, revealing that mineral separate techniques misrepresent rare earth element (REE) signatures. Chapter 3 examines garnets and clinopyroxenes from the Victorio Mining District skarn, showing that REE incorporation was controlled by fluid composition rather than crystal chemistry. Chapters 4 and 5 focus on extraterrestrial samples. Chapter 4 finds that garnets and pyroxenes in Allende CV3 matrix …

Late Cretaceous Ammonites And Other Non-Rudist Mollusks From Costa Rica And Their Paleoecology, Esteban David Lopez-Murillo

Earth and Planetary Sciences ETDs

The Nicoya region in northwestern Costa Rica contains a rich record of Upper Cretaceous fossiliferous sediments, which have received variable levels of study over the past several decades. In particular, rudists from these deposits have been well-characterized, however, the non-rudist ammonite, gastropod, and bivalve fauna have received much less attention. However, this area is particularly important because the Nicoya region was attached to the southernmost tip of North America, making it a unique crossroad between the western Tethys (Caribbean) and Pacific Oceans. Here I present a detailed investigation of these rocks and their fauna between the Late Campanian to Early …

Ambient Noise Tomography Of The Southern M9.2 1964 Great Alaska Earthquake Rupture Area, Joshua Ojuoluwa Osasona

Earth and Planetary Sciences ETDs

We used data from a densely spaced node array to investigate seismic velocity structure within the southern rupture area of the M9.2 1964 Great Alaska earthquake. The node array was deployed along a ~50 km section of the road system on Kodiak Island as part of the Alaska Amphibious Community Seismic Experiment (AACSE). The full ~400-node array was active for 25 days in May-June 2019. We extracted Rayleigh wave dispersion curves from ambient noise cross-correlations between station pairs in the node array to compute phase velocity maps from 2-8 s periods. Using these phase velocity maps, we performed a Bayesian …

Crustal Structure And Evolution Of The Queen Charlotte Plate Boundary, Collin C. Brandl

Earth and Planetary Sciences ETDs

There are many outstanding questions in plate tectonics that remain unanswered because large regions of the Earth are unexplored, both at the surface and in the subsurface. In this dissertation, I processed and analyzed active source seismic reflection data from the historically understudied Queen Charlotte transform plate boundary. Using this dataset, I found that the southern segment of the plate boundary has active underthrusting, is analogous to subduction zone crustal slivers, and is a site of early subduction initiation. Along the entire plate boundary, I constrained the near-surface thermal gradient using the stability of gas hydrate, finding that it is …

Differential River Incision Due To Quaternary Faulting On The Río Jemez-Salado System At The Million-Year Timescale, Cameron Reed

Earth and Planetary Sciences ETDs

Analysis of long-term average bedrock incision rates along the Río Salado-Jemez system using fluvial terraces can be used to test and quantify the hypothesis that differential river incision reflects Quaternary fault slip during ongoing uplift of the Jemez and Nacimiento Mountains. Terrace flights were correlated from the Arroyo Peñasco to the Río Salado near the southern nose of the Nacimiento and along the Río Jemez. Using highest/oldest river terraces, resulting bedrock incision values average out glacial/interglacial cycles and are interpreted to reflect differential uplift. For previously mapped and correlated terraces, we applied lidar datasets to refine strath heights. We also …

Sulfur Sequestration In Anhydrite Through Alteration Of Calcic Wall Rock, Lexi Kenis

Earth and Planetary Sciences ETDs

Heterogeneous gas-solid reactions are suggested as a potential mecha-
nism for sequestering gaseous sulfur through the alteration of calcic wall
rocks. This study explores the concept of a “hierarchy of reactions” pro-
posed by Giggenbach (1987), outlining the interplay between gas components
and redox-related minerals in volcanic wall rocks. Mt. Pinatubo provides a
more felsic composition and more oxidizing conditions compared to previ-
ously studied volcanoes, Kudryavy and Erta Ale (Henley and Fischer, 2021),
and Lascar a more oxidizing case with a similar composition. By employing
thermodynamic models and synthetic melt experiments, evaluations of effi-
ciency of sulfur sequestration across …

Proterozoic Tectonic Evolution Of The Lower Granite Gorge, Grand Canyon, Arizona: A Middle Crustal Record Of Multiple Orogenic Pulses, John M. Bailey

Earth and Planetary Sciences ETDs

The well-exposed basement transect in the Lower Granite Gorge (LGG) of western Grand Canyon provides a middle-crustal record of suturing crustal blocks during the Proterozoic accretionary history of southwestern Laurentia. Orogenic evolution included at least three stages: (1) subduction-related ~1.75-1.72 Ga volcanic arc magmatism, turbidite deposition, and suturing of arc terranes with different crustal thicknesses; (2) intense northwest-southeast crustal shortening at ca. 1.71-1.68 Ga to form the Vishnu Mountains during the Yavapai orogeny; (3) dextral strike-slip shear zones development at ~1.4 Ga during long-term crustal residence and slow cooling above ~250 °C (~10 km) until ~1.3 Ga. Final cooling from …

Chemical And Morphological Characterization Of Airborne Particulate Matter At The Jackpile-Paguate Mine, Pueblo Of Laguna, New Mexico: Implications For Potential Metals Exposure, Andreanna C. Roros

Earth and Planetary Sciences ETDs

The inhalation of windblown particulate matter (PM) derived from abandoned uranium mines (AUMs) is a potential environmental health risk to Native American communities that live in proximity to these sites. However, the aeolian transport of metal-bearing PM from AUMs, as a potential exposure pathway, has not been investigated in any detail. In this study, we sampled airborne particulate matter within the Jackpile Mine located on the lands of the Pueblo of Laguna, New Mexico using passive sampling methods to understand the characteristics of dust within the mine site. The objective was to determine the elemental concentrations, mineralogy, and morphology of …

Carbonate And Organic Proxies And The Impacts Of Climate On Lake Systems: Paleoclimate Interpretations From Lake Chalco, Mexico, Aria Holmes

Earth and Planetary Sciences ETDs

This project incorporates several lines of evidence to better understand the climate at Lake Chalco. Chapter 1 utilizes oxygen isotopes from carbonates and show that the Inter Tropical Convergence Zone varies on primarily glacial and millennial timescales; precession is not observed. These data indicate glacials periods were shallower and interglacials were wetter periods at Lake Chalco. Chapter 2 studies carbon, nitrogen, C/N, and TOC proxies and finds that the lake conditions during the glacials and interglacials are primarily a mixed algal-macrophyte-terrestrial organic matter. Deviations show that the lake during the interglacials had more algal organic matter- reflecting influxes of nutrients …

Sand, Ice, And X-Rays: Developing Xct Methods For Frozen Samples And Refining Siliciclastic Facies Models For Perennially Ice-Covered Lakes, Utilizing Cores From Lake Fryxell, Mcmurdo Dry Valleys, Antarctica, Holly M. Levett

Earth and Planetary Sciences ETDs

Sedimentation in perennially ice-covered lakes (PICLs) is proposed to be bi-modal, with mud deposited by stream inflow and sand deposited on the ice cover by aeolian processes and then melting through by absorption of solar radiation. Here, we consider Lake Fryxell, a PICL in the McMurdo Dry Valleys, and several lake bed cores about 30 cm in length, to better understand PICL facies through time, using micro X-ray CT (XCT). Using XCT images along with sieve and laser granulometry data, we constrained the grain-size of PICL deposits to dominantly medium / fine sand with a coarse component. The presence of …

Gnss And Insar Observations Of Vertical Motion In The Valles Caldera, Nm, Savannah Chase Devine

Earth and Planetary Sciences ETDs

The Valles caldera is a rhyolitic “supervolcano” formed 1.231 Ma. An understanding of whether Valles caldera is currently deforming is needed to inform volcanic hazard estimates for northern New Mexico and will allow for a better understanding of the hazards presented by other rhyolitic caldera systems. Here, we present an InSAR time series of the Valles Caldera using 37 interferograms, spanning 2014 to 2022, which show a small but consistent signal of broad pattern subsidence/yr. We also present GNSS observations from a survey conducted in October 2022 and compare the results to surveys in 2002 and 2003 to estimate the …

Sub-Stage Climatic Shifts During Mis 11 Refined From Diatom Assemblage Reconstruction In The Valles Caldera, New Mexico, Savannah Cutler

Earth and Planetary Sciences ETDs

Diatom assemblage reconstruction from the Valles Caldera sediment core (VC-3) was utilized to infer climatic and aquatic changes during a 50-thousand-year [ka] period in the Mid-Pleistocene (435-385 ka). This 50 ka interval spans most of Marine Isotope Stage 11 (MIS 11) – one of the most prominent interglacials of the past 500 ka – and is widely considered an analog for the Holocene and future climate regimes. Nearly all records from MIS 11 are either marine or ice-core based, making VC-3 unique among lacustrine sediment records as it captures insolation variations and climatic changes during the mid-Pleistocene. Analysis of the …

Unboxing The Complicated Near Term Climatic And Geomorphic History Of Mars, Joshua Matthew Williams

Earth and Planetary Sciences ETDs

It has long been thought that glacial processes were unlikely within the tropical regions of Mars. However, growing evidence, including this work has identified and quantified relic glacial forms within the equatorial regions. These findings have major implications for understanding Martian climate history and its sensitivity to changes in insolation. As well, the presence of ice in the equatorial region of Mars has significant implications for the past global redistribution of the water ice in the Martian cryosphere. In this manuscript, I clarify and refine our understanding of the morphology of glacial features in the equatorial zone by applying novel …

Paleoecology Of The Late Cretaceous Western Interior Seaway And Gulf Coastal Plain, Ceara Kathleen Quinn Purcell

Earth and Planetary Sciences ETDs

This dissertation presents research into the paleobiogeography and paleoecology of the Western Interior Seaway (WIS) and Gulf Coastal Plain (GCP) during the Late Cretaceous. The dataset utilized here includes an extensive record of marine invertebrates from over 200 years of fossil collecting and sedimentary data collated from over 45 different literature sources, representing approximately 17 million years of deposition. The high-resolution of this dataset, and its extensive geographic distribution and temporal duration, make it ideal for exploring various ecological questions. Using these data, I have attempted to reconstruct paleobiogeographic provinces as published in prior works, explore functional diversity patterns, and …

Remote Sensing Techniques To Determine Volcanic Gas Components And Fluxes: Application For Lascar, Chile And Fagradalsfjall, Iceland Volcanos., Felipe S. Rojas Vilches

Earth and Planetary Sciences ETDs

Volcanic plumes allow us to understand different aspects of a volcanic system including magma movements, dynamics, mass transfer, overall gas emissions to the atmosphere, and many processes that impact human life. However, the H₂O gas is poorly constrained due to the intrinsic difficulties of this gas, with high background values and easily dispersed/integrated into the background. In this work we study the gas emissions from Lascar volcano, and Fagradalsfjall volcano, in Chile and Iceland, respectively, using a combination of different ground-based remote sensing techniques and in situ plume measurements, we measure H₂O, SO₂, CO₂, CO, and H₂S from longer and …