This study presents an analysis of fault scarps, with a focus on implementing the Landlab computational toolkit to model fault scarp evolution and analyzing fault scarps under transport and production-limited conditions with linear and nonlinear diffusive transport laws. The aim of the study is to expand diffusion modeling of fault scarps from 1D to 2D by using Landlab toolkit. The study evaluated two fault scarps in western US (NE California): one representing an old fault scarp (Twin Butte) and the other representing a young fault scarp (Active Hat Creek Fault). High-resolution digital elevation models (DEMs) were used to generate 2D surfaces of the fault scarps, which were then converted to 1D profiles for morphological modeling and analysis. The accuracy of the models was evaluated using Root Mean Squared Error (RMSE), and the best-fit models were selected for further examination. The grid search of the non-linear diffusion model of the Twin Butte and Active Hat Creek fault scarps showed optimum values for transport constant (k) and scarp age (t) that aligned with the apparent ages of the rocks and associated fault scarps. For both fault scarps, the optimum k value was around 7.5 m2 /kyr, while the optimum t value was around 110 kyr for the Twin Butte scarp and around 26 kyr for the Active Hat Creek scarp. The results suggest that the geomorphic processes (influenced by climate and rock types) in both fault scarps are similar, despite the difference in age and location. Integrating tectonic displacement in the model helps to better capture the observed patterns of tectonic deformation. The expansion of the fault scarps diffusion model from 1D to 2D opens up a range of fascinating possibilities, as it enables us to model the lateral movement of particles that the 1D model typically overlooks. By incorporating this additional dimension, we can better understand the complex interplay between vertical and horizontal displacements, providing a more accurate representation of the geological processes at work. This advancement ultimately allows for a more comprehensive analysis of fault scarps and their development over time, enhancing our understanding of Earth's dynamic crustal movements.

Despite the rapid adoption of robotics and machine learning in industry, their application to scientific studies remains under-explored. Combining industry-driven advances with scientific exploration provides new perspectives and a greater understanding of the planet and its environmental processes. Focusing on rock detection, mapping, and dynamics analysis, I present technical approaches and scientific results of developing robotics and machine learning technologies for geomorphology and seismic hazard analysis. I demonstrate an interdisciplinary research direction to push the frontiers of both robotics and geosciences, with potential translational contributions to commercial applications for hazard monitoring and prospecting. To understand the effects of rocky fault scarp development on rock trait distributions, I present a data-processing pipeline that utilizes unpiloted aerial vehicles (UAVs) and deep learning to segment densely distributed rocks in several orders of magnitude. Quantification and correlation analysis of rock trait distributions demonstrate a statistical approach for geomorphology studies. Fragile geological features such as precariously balanced rocks (PBRs) provide upper-bound ground motion constraints for hazard analysis. I develop an offboard method and onboard method as complementary to each other for PBR searching and mapping. Using deep learning, the offboard method segments PBRs in point clouds reconstructed from UAV surveys. The onboard method equips a UAV with edge-computing devices and stereo cameras, enabling onboard machine learning for real-time PBR search, detection, and mapping during surveillance. The offboard method provides an efficient solution to find PBR candidates in existing point clouds, which is useful for field reconnaissance. The onboard method emphasizes mapping individual PBRs for their complete visible surface features, such as basal contacts with pedestals–critical geometry to analyze fragility. After PBRs are mapped, I investigate PBR dynamics by building a virtual shake robot (VSR) that simulates ground motions to test PBR overturning. The VSR demonstrates that ground motion directions and niches are important factors determining PBR fragility, which were rarely considered in previous studies. The VSR also enables PBR large-displacement studies by tracking a toppled-PBR trajectory, presenting novel methods of rockfall hazard zoning. I build a real mini shake robot providing a reverse method to validate simulation experiments in the VSR.

Mountain landscapes reflect competition between tectonic processes acting to build topography and erosive processes acting to wear it down. In temperate mountain landscapes, bedrock rivers are the primary erosional agent, setting both the pace of landscape evolution and form of the surrounding topography. Theory predicts that river steepness is sensitive to climatic, tectonic, and lithologic factors, which dictate the rates and mechanics of erosional processes. Thus, encoded into topography is an archive of information about forces driving landscape evolution. Decoding this archive, however, is fraught and climate presents a particularly challenging conundrum: despite decades of research describing theoretically how climate should affect topography, unambiguous natural examples from tectonically active landscapes where variations in climate demonstrably influence topography are elusive. In this dissertation, I first present a theoretical framework describing how the spatially varied nature of orographic rainfall patterns, which are ubiquitous features of mountain climates, complicate expectations about how climate should influence river steepness and erosion. I then apply some of these ideas to the northern-central Andes. By analyzing river profiles spanning more than 1500 km across Peru and Bolivia, I show that the regional orographic rainfall pattern this landscape experiences systematically influences fluvial erosional efficiency and thus topography. I also show how common simplifying assumptions built into conventional topographic analysis techniques may introduce biases that undermine detection of climatic signatures in landscapes where climate, tectonics, and lithology all covary – a common condition in mountain landscapes where these techniques are often used. I continue by coupling this analysis with published erosion rates and a new dataset of 25 cosmogenic 10Be catchment average erosion rates. Once the influence of climate is accounted for, functional relationships emerge among channel steepness, erosion rate, and lithology. I then use these functional relationships to produce a calibrated erosion rate map that spans over 300 km of the southern Peruvian Andes. These results demonstrate that accounting for the effects of climate significantly enhances the ability to decode channel steepness patterns. Along with this comes the potential to better understand rates and patterns of tectonic processes, and identify seismic hazards associated with tectonic activity using topography.

The South Tibetan Detachment System (STDS) marks a major decoupling horizon in the Himalaya, separating the highly metamorphosed infrastructure in the footwall from the weakly to unmetamorphosed superstructure in the hanging wall. The STDS stretches the entire range and is likely one of the most significant deformational features of the orogen, but its spatial and temporal evolution remain relatively unconstrained. As its name suggests, the STDS is a system of faults which occur at slightly different structural levels and are often diachronous. Detailed studies on the different strands are needed to understand the slip history of the system as a whole, which in turn will improve understanding of Himalayan orogenesis, thus informing tectonic models for continental orogenesis in general. I focus on some of the best exposed strands of the STDS which are located in the Annapurna region of Nepal. Outcrops within the shear zones of basal structures in the Kali Gandaki and Marsyandi valleys – the Annapurna and Chame detachments – contain leucogranites that are variably deformed via ductile slip on the detachments. I used U/Pb zircon and Th/Pb monazite geochronology to constrain emplacement ages of these leucogranites, which suggest ductile slip ceased prior to 14.95 ± 0.78 Ma and 16.0 ± 1.1 Ma on the Annapurna and Chame detachments respectively. 40Ar/ 39Ar muscovite and biotite, (U-Th)/He zircon and apatite thermochronology data and resulting thermal-kinematic models for samples I collected in the shear zones and footwalls of these detachments suggest further slip was ongoing on both detachments until ca. 12 Ma, although the majority of slip on the Chame detachment likely ceased by ca. 15-14 Ma. I also collected samples in the footwall of a structurally higher detachment in the Marsyandi and the resulting cooling ages and thermal-kinematic models suggest slip was contemporaneous with that on the lower Chame detachment. The new constraints on N-S extension on the STDS in the Annapurna region presented in this dissertation call into question the popular idea of a geodynamic change from N-S to E-W extension in the central Himalaya during the early Miocene, and emphasize the importance of the STDS as a major decoupling horizon.

The Greater Obsidian Pool Area just south of the Mud Volcano area in Yellowstone National Park is an active and ever-changing hot spring region. Situated next to a lake in a meadow between several hills of glacial deposits, north of the Elephant Back rhyolite flow, a diverse group of hot springs has been developing. This study examines the geologic and geomorphic context of the hot springs, finding evidence for a previously undiscovered hydrothermal explosion crater and examining the deposits around the region that contribute to properties of the groundwater table. Hot spring geochemical measurements (Cl- and SO4-2) taken over the course of 20 years are used to determine fluid sourcing of the springs. The distribution of Cl-, an indicator of water-rock interaction, in the hot springs leads to the theory of a fissure delivering hydrothermal fluid in a line across the hot spring zone, with meteoric water from incoming groundwater diluting hot springs moving further from the fissure. A possible second dry fissure delivering mostly gas is also a possible explanation for some elevated sulfate concentrations in certain springs. The combination of geology, geomorphology, and geochemistry reveals how the surface and subsurface operate to generate different hot spring compositions.

The tectonism, volcanism, and sedimentation along the East African Rift System (EARS) produced a series of rift basins with a rich paleoanthropological record, including a Late Miocene–present record of hominin evolution. To better understand the relationship between Earth system history and human evolution within the EARS, the Hominin Sites and Paleolakes Drilling Project (HSPDP) collected paleolake sediments near key paleoanthropological sites in Ethiopia and Kenya, compiling a multi-proxy, high-resolution geological and environmental record. As part of the HSPDP, I studied the detrital mineral record of the basins and evaluated tectonic and climatic controls on East African landscapes during the Plio-Pleistocene using samples from three of the drill sites, Chew Bahir: (CHB, ~620–present; Ethiopia), Northern Awash (NA, ~3.3–2.9 Ma; Ethiopia,), and West Turkana (WTK, ~1.9–1.4 Ma; Kenya). I employed laser ablation U/Pb and (U-Th)/He double dating (LADD) of detrital zircons, which yields paired U/Pb and (U-Th)/He dates, and (U-Th)/He dating of detrital apatites to evaluate sediment provenance and the cooling history of the source rocks. In addition, I used in situ 10Be cosmogenic radionuclide analyses to determine paleoerosion rates. Two chapters of this dissertation focus on results from the NA and WTK drill sites. Source units for the NA and WTK drill sites are largely Cenozoic volcanic rocks, and the detrital zircon record yields an extensive record of the timing of various phases of volcanism within the EARS. Exceptionally young zircon (U-Th)/He dates reflect partial resetting associated with late mafic volcanism and/or hydrothermal activity. Erosion rates are consistent and relatively low across the Plio-Pleistocene, despite significant tectonic and geomorphic shifts in the landscape. Two other chapters of this dissertation cover results from the CHB drill site. The Chew Bahir basin has significant exposures of Neoproterozoic and Early Paleozoic crystalline basement units, and the detrital zircon record yields one singular phase of volcanism in the EARS. The CHB erosion rates show an overall decreasing trend over time, consistent with an aridifying climate, and increased environmental variability after ~200 ka.

Faults found in the arid to semi-arid Basin and Range Physiographic province of the southwestern US are given broad age definitions in terms of which features appear to be the oldest. Particularly in the northwestern corner of Arizona, detailed geomorphic studies on the tectonic history and timing of faulting are not widespread. At the base of the Virgin Mountains in northwestern Arizona is a fault scarp along the Piedmont Fault line. This normal fault crosses a series of alluvial fans that are filled with sediments of ambiguous ages. Previous studies that were done in this region find a broad, Miocene age for the exhumation and uplift of these surfaces, with some indications of Laramide faulting history. However, specific fault characteristics and a time constraint of the tectonic history of the Piedmont Fault scarp has yet to be established. Here, we aim to determine the age, fault-slip rate, seismic history, and potential hazard of the fault scarp near Scenic and Littlefield, Arizona through structure from motion (SfM) modeling, which is a form of photogrammetry using a drone. In addition, we distinguish the climatic and tectonic influences on the geomorphology observed along the scarp through analysis along the fault line. With data collected from a ~500 m section of the fault, we present results from a digital elevation model (DEM) and orthophotos derived through the SfM modelling. Based on field observations and morphologic dating, we determine that the Piedmont Fault experiences an approximately continuous fault-slip and an earthquake recurrence interval in the range of 7,000 years. The approximate age of the scarp is 16.0 ka ± 5 kyr. Therefore, we conclude that the earthquake hazard posed to nearby cities is minimal but not nonexistent. Future work includes further analysis of fault profiles due to uncertainty in the present one and Terrestrial Cosmogenic Nuclide (TCN) dating of samples taken from the tops of boulders in a residual debris flow sitting on faulted and unfaulted alluvia. Determining the ages for these boulder surfaces can hopefully further inform our knowledge of the tectonic activity present in the North Virgin Mountains.

The project was designed to increase awareness of sustainability and environmental science in public high school students who would otherwise not be exposed to complex environmental problems. This was done by testing the effectiveness of a simple yet comprehensive curriculum that could satisfy and expand the scope of the Arizona Education Science Standard, Essential HS.E1U3.14, while simultaneously being accessible to (and teachable by) any school instructor. Another goal of the project is to stimulate the minds of students who would otherwise not be introduced to the topics of sustainability and environmental science. Utilizing proven visualization and engagement techniques, the curriculum focuses on five key subjects: waste, water, energy, ecosystems, and environmental challenges. Each of these subjects had an educational presentation, interactive activities, question and answer sessions, and bonus activities. To test the overall effectiveness of the curriculum, students were given a pretest to gauge initial comprehension, and then after the five subjects (or modules) were taught, the same test was distributed again to the students. The aforementioned was done with two groups of students. Posttest results support the project effectiveness. The data indicate that the lessons had a positive impact on the test results, with one class averaging 33.6% better on the posttest than the pretest, indicating that the concepts taught did resonate with the students in a measurable way.

Water has shaped the surface of Mars, recording previous environments and inspiring the search for extinct life beyond Earth. While conditions on the Martian surface today are not conducive to the presence of liquid water, ancient erosional and depositional features indicate that this was not always so. Quantifying the regional and global history of water on Mars is crucial to understanding how the planet evolved, where to focus future exploration, and implications for water on Earth.

Many sites on Mars contain layered sedimentary deposits, sinuous valleys with delta shaped deposits, and other indications of large lakes. The Hypanis deposit is a unique endmember in this set of locations as it appears to be the largest ancient river delta identified on the planet, and it appears to have no topographic boundary, implying deposition into a sea. I have used a variety of high-resolution remote sensing techniques and geologic mapping techniques to present a new model of past water activity in the region.

I gathered new orbital observations and computed thermal inertia, albedo, elevation, and spectral properties of the Hypanis deposit. I measured the strike and dip of deposit layers to interpret the sedimentary history. My results indicate that Hypanis was formed in a large calm lacustrine setting. My geomorphic mapping of the deposit and catchment indicates buried volatile-rich sediments erupted through the Chryse basin fill, and may be geological young or ongoing. Collectively, my results complement previous studies that propose a global paleoshoreline, and support interpretations that Mars had an ocean early in its history. Future missions to the Martian surface should consider Hypanis as a high-value sampling opportunity.

The movement between tectonic plates is accommodated through brittle (elastic) displacement on the plate boundary faults and ductile permanent deformation on the fault borderland. The elastic displacement along the fault can occur in the form of either large seismic events or aseismic slip, known as fault creep. Fault creep mainly occurs at the deep ductile portion of the crust, where the temperature is high. Nonetheless, aseismic creep can also occur on the shallow brittle portion of the fault segments that are characterized by frictionally weak material, elevated pore fluid pressure, or geometrical complexity. Creeping segments are assumed to safely release the accumulated strain(Kodaira et al., 2004; Rice, 1992)(Kodaira et al., 2004; Rice, 1992)(Kodaira et al., 2004; Rice, 1992)(Kodaira et al., 2004; Rice, 1992)(Kodaira et al., 2004; Rice, 1992) on the fault and also impede propagation of the seismic rupture. The rate of aseismic slip on creeping faults, however, might not be steady in time and instead consist of successive periods of acceleration and deceleration, known as slow slip events (SSEs). SSEs, which aseismically release the strain energy over a period of days to months, rather than the seconds to minutes characteristic of a typical earthquake, have been interpreted as earthquake precursors and as possible triggering factor for major earthquakes. Therefore, understanding the partitioning of seismic and aseismic fault slip and evolution of creep is fundamental to constraining the fault earthquake potential and improving operational seismic hazard models. Thanks to advances in tectonic geodesy, it is now possible to detect the fault movement in high spatiotemporal resolution and develop kinematic models of the creep evolution on the fault to determine the budget of seismic and aseismic slip.

In this dissertation, I measure the decades-long time evolution of fault-related crustal deformation along the San Andrea Fault in California and the northeast Japan subduction zone using space-borne geodetic techniques, such as Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR). The surface observation of deformation combined with seismic data set allow constraining the time series of creep distribution on the fault surface at seismogenic depth. The obtained time-dependent kinematic models reveal that creep in both study areas evolves through a series of SSEs, each lasting for several months. Using physics-based models informed by laboratory experiments, I show that the transient elevation of pore fluid pressure is the driving mechanism of SSEs. I further investigate the link between SSEs and evolution of seismicity on neighboring locked segments, which has implications for seismic hazard models and also provides insights into the pattern of microstructure on the fault surface. I conclude that while creeping segments act as seismic rupture barriers, SSEs on these zones might promote seismicity on adjacent seismogenic segments, thus change the short-term earthquake forecast.