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Nanoscale Evidence For Temperature-Induced Transient Rheology And Postseismic Fault Healing, Alexis K. Ault, Jordan L. Jensen, Robert G. Mcdermott, F.-A. Shen, B. R. Van Devener
Nanoscale Evidence For Temperature-Induced Transient Rheology And Postseismic Fault Healing, Alexis K. Ault, Jordan L. Jensen, Robert G. Mcdermott, F.-A. Shen, B. R. Van Devener
Geosciences Faculty Publications
Friction-generated heat and the subsequent thermal evolution control fault material properties and thus strength during the earthquake cycle. We document evidence for transient, nanoscale fault rheology on a high-gloss, light-reflective hematite fault mirror (FM). The FM cuts specularite with minor quartz from the Pleistocene El Laco Fe-ore deposit, northern Chile. Scanning and transmission electron microscopy data reveal that the FM volume comprises a2+ suboxides. Sub–5-nm-thick silica films encase hematite grains and connect to amorphous interstitial silica. Observations imply that coseismic shear heating (temperature >1000 °C) generated transiently amorphous, intermixed but immiscible, and rheologically weak Fe-oxide and silica. Hematite regrowth in …
Sorption Temperature And And The Stability Of Iron-Bound Soil Organic Matter, Michael L. Nguyen
Sorption Temperature And And The Stability Of Iron-Bound Soil Organic Matter, Michael L. Nguyen
Doctoral Dissertations
The preservation of soil organic matter (SOM) is an important control on the global cycling of carbon. Long-term preservation of SOM has important implications on soil fertility and climate regulation. Minerals, such as iron oxides, can react with SOM and serve as a preservation mechanism for SOM. Globally, iron oxide-SOM interactions form a “rusty carbon sink” which protects up to 22% of organic carbon in marine sediments. Climate changes, such as warming, may alter the size or efficacy of the “rusty carbon sink.” The effects of temperature, SOM composition, and mineral particle size on the formation and stability of iron …
Evaluation Of Pre-Eruptive Conditions For Cordon Caulle Rhyo-Dacitic Historic Eruptions, Mauro Andres Mingo
Evaluation Of Pre-Eruptive Conditions For Cordon Caulle Rhyo-Dacitic Historic Eruptions, Mauro Andres Mingo
FIU Electronic Theses and Dissertations
For better understanding of Plinian-hybrid eruptive events, I analyzed the variables that affect the pre-eruptive conditions of the latest three eruptive events of the Puyehue Cordon Caulle Volcanic Complex (PCCVC). The analysis was done by performing a petrological study of lava samples followed by Electron Probe Microanalysis (EPMA) on selected mineral phases. Mineral data were then used in established mathematical models to calculate pre-eruptive magma temperature and water content. The acquired data are compared to bulk measured water content, and the difference is utilized to estimate viscosities and evaluate the degassing regime. Results indicate that the historic eruptive events have …
Experiment On Methane Displacement In Coalbed By Supercritical Carbon Dioxide, Wu Di, Liu Xueying, Sun Keming, Xin Liwei, Miao Feng
Experiment On Methane Displacement In Coalbed By Supercritical Carbon Dioxide, Wu Di, Liu Xueying, Sun Keming, Xin Liwei, Miao Feng
Coal Geology & Exploration
Using self-made experimental system, experiments were performed on coal samples to study supercritical CO2 seepage, adsorption and CH4 displacement by supercritical CO2. Experimental results show that permeability and adsorption of supercritical CO2 in coal increase with CO2 pressures. Pressures and temperatures of CO2 influence the values of displaced CH4. Values of displaced CH4 increase by average 0.076 cm3/g and sweep efficiency rises by 17%-23% with the CO2 pressure increasing from 8 MPa to 12 MPa, while displacement volume decreases linearly. With the temperature rising by 10℃, sweep …
Determining The Influence Of Lateral Margin Mechanical Properties On Glacial Flow, Kate Hruby
Determining The Influence Of Lateral Margin Mechanical Properties On Glacial Flow, Kate Hruby
Electronic Theses and Dissertations
The lateral margins of glaciers and ice streams play a significant role in glacial flow. Depending on their properties, like temperature and ice crystal orientation, they can cause a resistance to flow or enhance it. In combination with our current changing climate, flow patterns can dictate the mass balance of an ice body. It is therefore more important than ever to understand the impact that variations at the margins can have on flow. However, the lateral margins of glaciers and ice streams are an often-neglected part of ice dynamics; they are harder to sample than the center of a glacier’s …
Multi-Resolution Spatio-Temporal Change Analyses Of Hydro-Climatological Variables In Association With Large-Scale Oceanic-Atmospheric Climate Signals, Kazi Ali Tamaddun
Multi-Resolution Spatio-Temporal Change Analyses Of Hydro-Climatological Variables In Association With Large-Scale Oceanic-Atmospheric Climate Signals, Kazi Ali Tamaddun
UNLV Theses, Dissertations, Professional Papers, and Capstones
The primary objective of the work presented in this dissertation was to evaluate the change patterns, i.e., a gradual change known as the trend, and an abrupt change known as the shift, of multiple hydro-climatological variables, namely, streamflow, snow water equivalent (SWE), temperature, precipitation, and potential evapotranspiration (PET), in association with the large-scale oceanic-atmospheric climate signals. Moreover, both observed datasets and modeled simulations were used to evaluate such change patterns to assess the efficacy of the modeled datasets in emulating the observed trends and shifts under the influence of uncertainties and inconsistencies. A secondary objective of this study was to …
Wildfires In The Northeastern United States: Evaluating Fire Occurrence And Risk In The Past, Present, And Future, Daniel R. Miller
Wildfires In The Northeastern United States: Evaluating Fire Occurrence And Risk In The Past, Present, And Future, Daniel R. Miller
Doctoral Dissertations
Climate change is one of the most complex and challenging issues facing the world today. A changing climate will affect humankind in many ways and alter our physical environment, presenting ethical challenges in how we respond. The impact of climate change will likely be exacerbated in heavily populated regions of the planet, such as the Northeastern United States (NEUS). The NEUS is comprised of complex, sprawling urban centers and rural regions, both of which are vital to the economic and cultural character of the region. Furthermore, both urban and rural areas in the NEUS contain communities that have been historically …
Examination Of The Climate Factors That Reduced Wheat Yield In Northwest India During The 2000s, Avik Mukherjee, Shih-Yu (Simon) Wang, Parichart Promchote
Examination Of The Climate Factors That Reduced Wheat Yield In Northwest India During The 2000s, Avik Mukherjee, Shih-Yu (Simon) Wang, Parichart Promchote
Plants, Soils, and Climate Faculty Publications
In India, a significant reduction of wheat yield would cause a widespread impact on food security for 1.35 billion people. The two highest wheat producing states, Punjab and Haryana in northern India, experienced a prolonged period of anomalously low wheat yield during 2002–2010. The extent of climate variability and change in influencing this prolonged reduction in wheat yield was examined. Daily air temperature (Tmax and Tave) was used to calculate the number of days above optimum temperature and growing degree days (GDD) anomaly. Two drought indices, the standard precipitation and evapotranspiration index and the radiation-based precipitation index, …
Carbon Dioxide Measurement In Irish Blanket Peatlands: An Assessment Of Pool-Soil Flux Variability, Mariya Radomski, Alan Gilmer, Vivienne Byers, Eugene Mcgovern
Carbon Dioxide Measurement In Irish Blanket Peatlands: An Assessment Of Pool-Soil Flux Variability, Mariya Radomski, Alan Gilmer, Vivienne Byers, Eugene Mcgovern
Articles
Peatlands have been recognised as having a significant role in the mediation of atmospheric carbon dioxide (CO2) levels with direct implications for global climate change. Longitudinal in situ measurement systems for CO2 concentrations in blanket peatland ecosystems are difficult to implement where the nature of terrestrial–aquatic connectivity and hydrodynamics have a significant effect on the carbon cycle. The need for greater data on CO2 concentrations and flux monitoring in these settings has been well recognised. However, applying the most appropriate monitoring approach presents a special challenge. This paper sets out the development of a direct method for field based longitudinal …
Meteorological Comparison Of Three Cave Systems, Matthew Wine
Meteorological Comparison Of Three Cave Systems, Matthew Wine
Mahurin Honors College Capstone Experience/Thesis Projects
Cave systems are home to delicate underground ecosystems that can be affected by changes in surface atmospheric conditions which in turn affect underground meteorology. Modern human use of caves is typically for tourism, so understanding surface-underground weather-climate interactions is important when caves carry streams that are prone to flooding in response to surface precipitation. The purpose of this research is to document the effects of surface weather conditions on cave meteorology in three different cave system types located in different geographic locations including an island, the central USA, and at high elevations in British Columbia. The study caves include Kaumana …