Browsing Earth and Space Sciences by Title
Now showing items 38-57 of 120
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Greenland outlet glacier behavior during the 21st century: Understanding velocities and environmental factors
Outlet glacier ice dynamics, including ice-flow speed, play a key role in determining Greenland Ice Sheet mass loss, which is a significant contributor to global sea-level rise. Mass loss from the Greenland Ice Sheet ... -
Hillslope erosion and weathering rates in Earth's most rapidly uplifting mountains
(2014-02-24)Knowledge of hillslope erosion rates and processes is necessary for understanding landscape response to tectonic and climatic forcing and for determining the degree to which mountains regulate biogeochemical cycles and ... -
Hydrated silica on Mars: Global comparison and in-depth analysis at Antoniadi Crater
(2012-09-13)Hydrated silica is found in a variety of Martian deposits within suites of minerals that indicate aqueous alteration, mostly because hydrated silica forms easily in different environments. Because of its relative ubiquity ... -
Imaging northern Cascadia wave speed structure and slow slip
I calculate tremor source amplitudes for the northern Cascadia episodic tremor and slip (ETS) events from 2007-2010 and find they exhibit similar spatiotemporal patterns of radiated energy from tectonic tremor. In the ... -
Implications and Limitations of Tremor as a Proxy for Slow Slip
This thesis seeks to integrate geodetic and seismic observations to explore the relationship between tremor and slow slip on subduction zones. In particular, I evaluate the one-to-one relationship of tremor and slip in ... -
Innovations in pulsed plasma thrusters to enable CubeSat science missions
CubeSats and other small satellites in the 3-25 kg range are increasingly able to conduct meaningful science through advances in technology and miniaturization. However, much of the proposed science requires satellite ... -
Investigating the drivers of glacier retreat in West Antarctica using proxy-data assimilation and numerical modeling
Outlet glaciers in West Antarctica are rapidly retreating and contributing to sea level rise. Ice loss is primarily occurring via wind-driven incursions of warm circumpolar deep water melting the ice shelves that buttress ... -
Investigating the effects of <italic>Bacillus subtilis</italic> endospore surface reactivity on low-temperature aqueous geochemical systems
Microbes are a ubiquitous component in water-rock systems including ground and surface waters, soils, mid-ocean ridge hydrothermal systems, and deep sedimentary basins. Microbial envelopes provide complex organic surfaces ... -
Investigating the evolution of fault scarps in jointed volcanic rock through field evidence, morphometric techniques and novel methods
The morphology of fault scarps in jointed volcanic rock records information on the tectonics, volcanism and geomorphology of a region. The evolution of scarp form has been modeled to extract information varying from the ... -
Investigating the interior of West Antarctica with light, radar, and electrical conductance
(2014-02-24)Ice sheets play an important role in both the modern climate and in past variations of Earth's history. Our understanding of ice sheets has been limited by few observations until recent advances in technology, notably air ... -
Investigating the roles of ice dynamics and climate on polar near-surface processes
Understanding processes in the snow and firn are important for studies of ice dynamics, ice-sheet mass balance, glacial hydrology, and ice-core interpretation. In this dissertation, I use a combination of modeling, geophysical ... -
Investigations of glacier terminus changes on weekly to decadal time scales
Glacier retreat and mass loss are contributing to global sea-level rise and environmental change. One method to improve our understanding of how glaciers affect local and global environments is to measure historical and ... -
Investigations of physical processes in polar firn through modeling and field measurements
Evolution of firn on the polar ice sheets is important for several applications in glaciology, including interpreting climate records from ice cores and correcting ice-sheet-elevation change measurements from altimetry for ... -
Landscape Response to Oblique Convergence: Insights from Numerical Modeling and from the Marlborough Fault System, New Zealand
Strike-slip and oblique faults are prominent tectonic features that can dramatically influence the landscape at all scales. In this dissertation, I explore the effects of strike-slip and oblique faults on the landscape, ... -
Landslides in Cascadia: Using geochronometry and spatial analysis to understand the timing, triggering and spatial distribution of slope failures in the Pacific Northwest United States
Landslides kill hundreds to thousands of people every year, cause billions of dollars in infrastructure damage, and act as important drivers of landscape evolution. In the Pacific Northwest USA, landslides routinely block ... -
Large woody debris and river morphology in scour pool formation, dam removal, and delta formation
The interactions between large woody debris, fluid flow, and sediment transport are a first-order control on river processes, affecting channel morphology at multiple scales. This thesis investigates how wood geometry and ... -
Magnesium isotope fractionation associated with biotic and abiotic weathering -and- Developing a scalable method for rare earth element extraction from non-traditional feedstocks using engineered Escherichia coli
This dissertation is divided into two sections, with the first discussing magnesium (Mg) isotope behavior during biotic and abiotic rock weathering, and the second describing the application of engineered microbes for the ... -
Mars' Water Cycle Seen Through an Ice Lens
The water cycle of Mars has been intensely studied thanks to data from orbiting spacecraft and landers on the surface. Water is of major interest due to its vital connection to life on Earth. The global cycle is driven by ... -
Measured and modeled albedos of sea-ice surfaces with implications for Snowball Earth
The Snowball Earth episodes were extensive glaciations that occurred during the Neoproterozoic, between 600 and 800 million years ago, during which ice covered much or all of the oceans. These glaciations were a result of ... -
Melt-Triggered Seismic Response in Hydraulically-Active Polar Ice: Observations and Methods
(2014-02-24)Glacier ice responds to environmental forcing through changes in its sliding speed and mass balance. While these changes often occur on daily time scales or longer, they are initiated by brittle deformation events that ...