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Microbial Diversity And Biogeochemical Interactions In The Seismically Active And Co2-Rich Eger Rift Ecosystem, Daniel Lipus, Zeyu Jia, Megan Sondermann, Robert Bussert, Alexander Bartholomäus, Sizhong Yang, Dirk Wagner, Jens Kallmeyer Dec 2024

Microbial Diversity And Biogeochemical Interactions In The Seismically Active And Co2-Rich Eger Rift Ecosystem, Daniel Lipus, Zeyu Jia, Megan Sondermann, Robert Bussert, Alexander Bartholomäus, Sizhong Yang, Dirk Wagner, Jens Kallmeyer

College of Life Sciences Faculty Papers

The Eger Rift subsurface is characterized by frequent seismic activity and consistently high CO2 concentrations, making it a unique deep biosphere ecosystem and a suitable site to study the interactions between volcanism, tectonics, and microbiological activity. Pulses of geogenic H2 during earthquakes may provide substrates for methanogenic and chemolithoautotrophic processes, but very little is currently known about the role of subsurface microorganisms and their cellular processes in this type of environment. To assess the impact of geologic activity on microbial life, we analyzed the geological, geochemical, and microbiological composition of rock and sediment samples from a 238 m deep drill …


Highway Crossing Rates Of Wild Felids Before, During, And After Wildlife Crossing Structure Installation, Sarah E. Lehnen, Mitch Sternberg, Hilary M. Swarts, John H. Young Jr., Victoria Hanley, Richard J. Kline Dec 2024

Highway Crossing Rates Of Wild Felids Before, During, And After Wildlife Crossing Structure Installation, Sarah E. Lehnen, Mitch Sternberg, Hilary M. Swarts, John H. Young Jr., Victoria Hanley, Richard J. Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

In an environment increasingly dominated by roads, wildlife crossing structures (WCS) have been installed to decrease wildlife mortality and improve habitat linkages. In South Texas, vehicle collisions have been a major mortality source for the endangered ocelot ( Leopardus pardalis ). To mitigate threats to this species, eight WCS, along with associated fencing, were strategically placed along Farm‐to‐Market Road 106 (FM106), which passes through ocelot habitat. We assessed the rate of on‐roadway crossings and WCS use by GPS‐collared animals before, during, and after WCS installation using camera traps to verify WCS use. Because of the rarity of ocelots in this …


Finite-Difference Time-Domain Simulation For Interpreting Regional Infrasound Arrivals And Estimating Propagation Path Effects, Jesse Howard Dec 2024

Finite-Difference Time-Domain Simulation For Interpreting Regional Infrasound Arrivals And Estimating Propagation Path Effects, Jesse Howard

Earth Sciences Theses and Dissertations

New full-wave infrasound simulation tools were developed based on an optimized finite-difference time-domain solution of 2D axisymmetric linear and nonlinear fluid dynamic equations. These tools were applied to estimate propagation path effects and enhance phase interpretation for regional infrasound arrivals. Middle-atmosphere full-wave predictions for a range of idealized atmospheres show that shadow zone arrivals and fast and slow arrival pair components from multiple ducts can be delineated using a combination of full-wave modeling and geometrical acoustics. Relationships between phase velocity and effective sound profile were established for each arrival type. Implications for source characterization were that amplitude and spectrum variation …


China’S Rare Earths Trade Flow Analysis: Trade Patterns And Strategic Insights, Linbin Tang, Peng Wang, Wei Chen, Yawen Han, Yuning Jin, Zilong Peng, Weiqiang Chen Dec 2024

China’S Rare Earths Trade Flow Analysis: Trade Patterns And Strategic Insights, Linbin Tang, Peng Wang, Wei Chen, Yawen Han, Yuning Jin, Zilong Peng, Weiqiang Chen

Bulletin of Chinese Academy of Sciences (Chinese Version)

Rare earth elements are strategic critical metals that support low-carbon energy, aerospace, and defense technologies. Currently, China’s rare earth industry lacks competitiveness and faces the risk of “multidimensional pressures” in global competition. Therefore, it is crucial to systematically analyze the supply-demand and trade patterns of rare earths, accurately identify the bottlenecks and pain points in China’s entire rare earth industry chain, and provide strategies to transform China’s rare earth resource advantage into a strategic competitive edge. Based on customs trade data, this study traces the trade flows of various forms of rare earth products across the full industry chain in …


Two Decades Of Climate Measurements Reveal El Niño's Role In Andean Elevation-Dependent Warming, Luke Davies Dec 2024

Two Decades Of Climate Measurements Reveal El Niño's Role In Andean Elevation-Dependent Warming, Luke Davies

Honors Program Theses and Projects

Driven by climate change, elevation-dependent warming (EDW) has become a critical issue in the Cordillera Blanca of Peru. This study focuses on gathering evidence of EDW and determining the relationship between El Niño Southern Oscillation (ENSO) events and micrometeorological forcing in two proglacial valleys. A climate monitoring network was maintained through a 20-year collaboration between Bridgewater State University (BSU), Universidad Nacional Santiago Antúnez de Mayolo (UNASAM), and the Autoridad Nacional de Agua (ANA). Fieldwork in June 2023 and June 2024 included repairing weather stations, installing new Lascar sensors, and downloading data loggers to sustain and improve the climate record. Data …


Unquantifiable: The Impacts Of Len Vacher, Victor J. Ricchezza, Nathan D. Grawe Dec 2024

Unquantifiable: The Impacts Of Len Vacher, Victor J. Ricchezza, Nathan D. Grawe

Numeracy

This article celebrates H.L. (Len) Vacher, the founding editor of Numeracy. While many readers of this journal are no doubt familiar with Len’s contributions here and to quantitative literacy as a practice and habit of mind, fewer are intimately familiar with Len’s history and impacts as a professor and colleague. This paper analyzes Len's contributions to the advancement of quantitative literacy through his scholarship in the journal and through the careers of former students and colleagues at the University of South Florida. The former observations originate in interview data originally collected as part of research on Len’s computational geology course …


Next-Generation Compositional And Chronological Sample Analysis Of Lunar Low-Ti Basalts And Volcanic Glasses, Christopher Yen Dec 2024

Next-Generation Compositional And Chronological Sample Analysis Of Lunar Low-Ti Basalts And Volcanic Glasses, Christopher Yen

Arts & Sciences Graduate Student Theses and Dissertations

The Moon, our celestial satellite, has been a source of awe and inspiration persistent through the course of humankind’s existence. Scientific exploration of the Moon began with terrestrial observations, and since the dawning of the space age has accelerated alongside technological advancements. Analysis of lunar samples has marked the remarkable advancement of our knowledge of not just our Moon, but also the formation and evolution of Earth and planetary bodies. Beginning with the Apollo program, human exploration has returned samples from the Moon that allow sophisticated laboratory studies that led to the development of major theories in the field of …


Organic Alkalinity Distributions, Characteristics, And Application To Carbonate System Calculations In Estuarine And Coastal Systems, Christopher W. Hunt, Joseph Salisbury, Xuewu Liu, Robert H. Byrne Dec 2024

Organic Alkalinity Distributions, Characteristics, And Application To Carbonate System Calculations In Estuarine And Coastal Systems, Christopher W. Hunt, Joseph Salisbury, Xuewu Liu, Robert H. Byrne

Faculty Publications

The capacity of aquatic systems to buffer acidification depends on the sum contributions of various chemical species to total alkalinity (TA). Major TA contributors are inorganic, with carbonate and bicarbonate considered the most important. However, growing evidence shows that many rivers, estuaries, and coastal waters contain dissolved organic molecules with charge sites that create organic alkalinity (OrgAlk). This study describes the first comparison of (1) OrgAlk distributions and (2) acid–base properties in contrasting estuary-plume systems: the Pleasant (Maine, USA) and the St. John (New Brunswick, CA). The substantial concentrations of OrgAlk in each estuary were sometimes not conservative with salinity …


The Role Of Nutrient Solutions On Phosphate-Solubilizing Bacteria Population, Phosphorus Availability, Phosphorus Uptake, Growth And Yield Of Red Chili (Capsicum Annuum L.), Betty Natalie Fitriatin, Raden Faqih Hilmiy Ghifari, Emma Trinurani Sofyan, Fitri Widiantini, Hanif Fakhrurroja, Tualar Simarmata Dec 2024

The Role Of Nutrient Solutions On Phosphate-Solubilizing Bacteria Population, Phosphorus Availability, Phosphorus Uptake, Growth And Yield Of Red Chili (Capsicum Annuum L.), Betty Natalie Fitriatin, Raden Faqih Hilmiy Ghifari, Emma Trinurani Sofyan, Fitri Widiantini, Hanif Fakhrurroja, Tualar Simarmata

Jurnal Kultivasi

Red chili consumption in Indonesia has increased every year. However, with large chili production to meet large consumption, land conversion for various purposes has reduced the harvested area. The efforts to increase the harvested area of chili using Inceptisols soil by providing nutrient solutions to overcome the infertility of the soil using its nutrients. This experiment aims to determine the effect of nutrient solution application on the population of phosphate-solubilizing bacteria, phosphorus availability, phosphorus uptake, growth, and yield of Red Chili (Capsicum annuum L.) in Inceptisols. The experiment was conducted from August 2023 to February 2024 at Ciparanje Experimental Field, …


Evaluating The Usefulness Of Geochronometers In The Packsaddle Domain For Refining The Timing Of Metamorphism Via High-Resolution Petrography, Enchanted Rock State Natural Area, Llano Uplift, Texas, Haylee Vike Dec 2024

Evaluating The Usefulness Of Geochronometers In The Packsaddle Domain For Refining The Timing Of Metamorphism Via High-Resolution Petrography, Enchanted Rock State Natural Area, Llano Uplift, Texas, Haylee Vike

Electronic Theses and Dissertations

The Llano uplift, central Texas, exhumes Mesoproterozoic rocks with a complex history of metamorphism, deformation, and magmatism. There are three recognized metamorphic events related to the Grenville orogeny (~1.3-0.9 Ga). The timing of these metamorphic events is not well resolved due to past methods, technology, and lack of published geologic context for many of the current dates. These current time constraints on metamorphic timing could be further refined through modern geochronologic and petrochronologic methods.

A majority of U-Pb zircon dates from the Valley Spring (~1366-1232 Ma), Coal Creek (~1326-1275 Ma), and Packsaddle (~1257-1215 Ma) domains are interpreted as crystallization ages …


Karst Hydrologic Memory Supplements Streamflow During Dry Periods In Snow-Dominated, Mountainous Watersheds, Hyrum Tennant, Bethany T. Neilson, Devon Hill, Dennis L. Newell, James P. Evans, Seohye Choi, James P. Mcnamara, Nathaniel Ashmead, Tianfang Xu Dec 2024

Karst Hydrologic Memory Supplements Streamflow During Dry Periods In Snow-Dominated, Mountainous Watersheds, Hyrum Tennant, Bethany T. Neilson, Devon Hill, Dennis L. Newell, James P. Evans, Seohye Choi, James P. Mcnamara, Nathaniel Ashmead, Tianfang Xu

Geosciences Faculty Publications

Analysis of PRISM and SNOTEL station data paired with USGS streamflow gage data in the western United States shows that, in snow-dominated mountainous watersheds, streamflow regimes differ between watersheds with karst geology and their non-karst neighbours. These carbonate aquifers exhibit a spectrum of flow paths encompassing karst conduits, including large fractures or voids that transmit water readily to springs and other surface waters, and matrix flow paths through soils, highly fractured bedrock, or porous media bedrock grains. A well-connected karst aquifer will discharge a large portion of its accumulated precipitation to surface water via springs and other groundwater flow paths …


Geomorphic Evolution Of St. Augustine Inlet, St. Johns County, Florida, Kristen Becker Dec 2024

Geomorphic Evolution Of St. Augustine Inlet, St. Johns County, Florida, Kristen Becker

Theses and Dissertations

Tidal inlets interrupt longshore sediment transport, influencing adjacent beach morphology and allowing the exchange of water and sediment between the open oceans and protected back barrier bay. Inlets evolve through a combination of natural processes and are highly dynamic zones where sediment exchanges cause shifting shoreline positions nearby and create new morphological features. Barrier islands/beaches that are close in proximity to inlets evolve and are an important natural feature that dissipates wave energy and protects inland areas. Both natural and anthropogenic processes that affect barrier islands will be investigated during this study, including storm activity, waves, wind, water level, and …


And Climate Justice For All Dec 2024

And Climate Justice For All

DePaul Magazine

DePaul is taking its environmental sustainability and equity prowess to the next level through its Just DePaul and President's Sustainability Committee initiatives that incorporate a climate action plan and student voices. Plus, community partnership courses that involve students in environmental action and justice efforts.


Are There Neurological Impacts Of Exposure To A Burned Wildfire Site As It Recovers?, Rubye Strickland Dec 2024

Are There Neurological Impacts Of Exposure To A Burned Wildfire Site As It Recovers?, Rubye Strickland

Undergraduate Honors Theses

Wildfires are increasing with climate change, making the human health implications of exposure to burned soils an essential area of research. Metals associated with fire-impacted soils can be inhaled or accidentally ingested by surrounding communities, causing health risks. Several studies have evaluated the health impact of wildfires, but few have done so from a neurological perspective. This study explores metal changes in burned soils over time as a site naturally recovers from wildfire and how these changes may impact human neurological health. Soil samples were collected from the burned area 0, 3, 6, 9, and 12 months after the fire. …


Algal Community Investigations: Present Day To Year-2100 For Mississippi Lakes And The Western Mississippi Sound, Emma Madison Tucker Dec 2024

Algal Community Investigations: Present Day To Year-2100 For Mississippi Lakes And The Western Mississippi Sound, Emma Madison Tucker

Theses and Dissertations

Algae play a key role in the aquatic environment as primary producers; however, they can form harmful algal blooms that are detrimental to the aquatic environment, people, and even the economy. It is generally believed that climate change will influence future algal blooms. The first study estimated algae community in three freshwater locations in Mississippi, Desoto Lake, White’s Creek Lake, and Columbus Lake, and one saline location, Western Mississippi Sound, using modern and new tools of the autonomous surface vessel, FlowCam, and EcoTaxa. From those results and leading into the second study was the application of four climate scenarios on …


Climate And Gypsum Parent Material Shape Biocrust Communities And Moss Ecology In The Chihuahuan And Mojave Deserts, Nicole Pietrasiak, Katelyn G. Gobbie, Brian Jusko, Rebecca E. Drenovsky Dec 2024

Climate And Gypsum Parent Material Shape Biocrust Communities And Moss Ecology In The Chihuahuan And Mojave Deserts, Nicole Pietrasiak, Katelyn G. Gobbie, Brian Jusko, Rebecca E. Drenovsky

Life Sciences Faculty Research

Biological soil crust communities (biocrusts) establishing on gypsum soils have been well-documented for their prolific appearance and rich diversity of lichens and bryophytes. However, studies characterizing gypsum biocrusts have occurred primarily outside of the U.S., most of which lack comparisons to other soil types. We conducted intensive field surveys to evaluate the ground cover and frequency of biocrust functional groups and moss species on gypsum and non-gypsum soils in the U.S. regions with the most extensive gypsum outcrops, the northern Chihuahuan and eastern Mojave Deserts. Study sites were stratified by geomorphology and paired, so that every gypsum site was matched …


Recovery Of Black Carbon Concentrations In Burned Forests In Wyoming, Usa, Monica Vanesa Zapata Villegas Dec 2024

Recovery Of Black Carbon Concentrations In Burned Forests In Wyoming, Usa, Monica Vanesa Zapata Villegas

Dissertations and Theses

Burned forests that remain standing following fire release light-absorbing particles (LAPs), including black carbon (BC), into winter snowpacks, reducing snow surface albedo and accelerating snowmelt timing for decades postfire. Although the role of LAPs in seasonal snow has been extensively studied, the spatiotemporal variability of LAPs' contributions to snowmelt relative to time-since-fire and burn severity remains unknown. This study aimed to quantify the spatiotemporal variability of forest fire effects on LAPs in snow and associated snow albedo in the Triple Divide region of western Wyoming, headwaters of the Colorado, Columbia, and Missouri rivers. Using geochemical analysis and radiative transfer modeling, …


Landslide Mapping, Characterization, And Hazard Assessment With 3d Slope Stability Modeling In White Bluffs, Washington State, Anna Tsitsivas Dec 2024

Landslide Mapping, Characterization, And Hazard Assessment With 3d Slope Stability Modeling In White Bluffs, Washington State, Anna Tsitsivas

Dissertations and Theses

Slope failures shape the landscape by moving unstable material downslope and, in doing so, become a great hazard to all those in their path. Understanding the mechanisms that control landslide location, timing, size, type, and runout - and therefore hazards - requires a deep understanding of the local geology, stratigraphy, and groundwater conditions. Along White Bluffs, in south-central Washington, landslides of several failure styles have likely been triggered by an increased water table in recent decades, threatening both farmland behind the bluffs and habitat below. This study focuses on characterizing potential groundwater sources and determining controls on spatial and temporal …


Growth And Yield Of Bok Choy (Brassica Rapa L.) Plants In Post-Rock Excavation Soils Provided With Phosphate-Solubilizing Bacteria And Manure, Cecep Hidayat, Yati Setiati Rachmawati, Dhea Rizqi Utami, Sofiya Hasani, Anna Aina Roosda, Windhy Chandria Dec 2024

Growth And Yield Of Bok Choy (Brassica Rapa L.) Plants In Post-Rock Excavation Soils Provided With Phosphate-Solubilizing Bacteria And Manure, Cecep Hidayat, Yati Setiati Rachmawati, Dhea Rizqi Utami, Sofiya Hasani, Anna Aina Roosda, Windhy Chandria

Jurnal Kultivasi

Elevated sand and gravel mining to meet market needs causes negative impacts on the environment, soil, and biodiversity. The government issued a regulation that requires revegetation as reclamation of mineral and coal mining. The conversion needs to overcome the physical and chemical characteristics of post-rock excavation soil that can be utilized by economic value plants such as bok choy. This experiment aimed to determine the growth and yield of bok choy on post-rock excavation soil by providing phosphate solubilizing bacteria (PSB) and various manure types. The study was conducted in Margasari Village, Buah Batu District, Bandung at an altitude of …


Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat Dec 2024

Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat

Jurnal Kultivasi

The contamination of shallots in the food chain by heavy metals such as lead (Pb) and cadmium (Cd) is caused by chemical fertilizers and pesticides. The study aimed to determine the growth and yields of shallot cultivated on soil contaminated with Pb and Cd using mycorrhiza and biochar. The study was conducted in the screen house at Jenderal Soedirman University, Faculty of Agriculture, from April to September 2020, and it was carried out using a factorial Randomized Completely Block Design that involved three replications and two factors. The first factor of mycorrhiza dosage comprised 0, 1, and 2 g/pot, and …


Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat Dec 2024

Bioremediation Of Pb And Cd Contaminated Soil By Mycorrhiza And Biochar Treatment And Its Effect On Growth And Yield Of Shallot, Okti Herliana, Wilis Cahyani, Yugi Rahayu Ahadiyat

Jurnal Kultivasi

The contamination of shallots in the food chain by heavy metals such as lead (Pb) and cadmium (Cd) is caused by chemical fertilizers and pesticides. The study aimed to determine the growth and yields of shallot cultivated on soil contaminated with Pb and Cd using mycorrhiza and biochar. The study was conducted in the screen house at Jenderal Soedirman University, Faculty of Agriculture, from April to September 2020, and it was carried out using a factorial Randomized Completely Block Design that involved three replications and two factors. The first factor of mycorrhiza dosage comprised 0, 1, and 2 g/pot, and …


Developing Resilient Organic Dryland Wheat Systems In The Face Of Climate Change., Jennifer R. Reeve Dec 2024

Developing Resilient Organic Dryland Wheat Systems In The Face Of Climate Change., Jennifer R. Reeve

Funded Research Records

No abstract provided.


Current Status And The Significance Of Local Wisdom Biofertilizer In Enhancing Soil Health And Crop Productivity For Sustainable Agriculture: A Systematic Literature Review, Irwandhi, Fiqriah Hanum Khumairah, Emma Trinurani Sofyan, Nadia Nuraniya Kamaluddin, Anne Nurbaity, Diyan Herdiyantoro, Tualar Simarmata Dec 2024

Current Status And The Significance Of Local Wisdom Biofertilizer In Enhancing Soil Health And Crop Productivity For Sustainable Agriculture: A Systematic Literature Review, Irwandhi, Fiqriah Hanum Khumairah, Emma Trinurani Sofyan, Nadia Nuraniya Kamaluddin, Anne Nurbaity, Diyan Herdiyantoro, Tualar Simarmata

Jurnal Kultivasi

Soil fertility is recognized as a crucial factor in supporting plant growth and productivity. The utilization of biofertilizers as environmentally friendly fertilizers is aimed at enhancing soil fertility and plant productivity. This study aims to explore the potential of local material for developing local wisdom biofertilizers (LWB) for achieving sustainable agriculture. A systematic literature review was conducted using bibliometric analysis, Preferred Reporting Items for Systematic Reviews, and Meta-Analyses (PRISMA) method, employing the Scopus search engine with the keywords "local AND wisdom AND biofertilizer" OR "biofertilizer" OR "local AND microorganism" OR "soil AND health OR crop AND productivity OR sustainable agriculture". …


Reconstructing Long-Term, High-Resolution Groundwater Storage Changes In The Songhua River Basin Using Supplemented Grace And Grace-Fo Data, Chuanqi Liu, Zhijie Zhang, Chi Xu, Wanchang Zhang Dec 2024

Reconstructing Long-Term, High-Resolution Groundwater Storage Changes In The Songhua River Basin Using Supplemented Grace And Grace-Fo Data, Chuanqi Liu, Zhijie Zhang, Chi Xu, Wanchang Zhang

Environment and Society Faculty Publications

The Gravity Recovery and Climate Experiment (GRACE) enables large-scale monitoring of terrestrial water storage changes, significantly contributing to hydrology and related fields. However, the coarse resolution of groundwater storage anomaly (GWSA) data limits local-scale research utilizing GRACE and GRACE-FO missions. In this study, we develop a regional downscaling model based on the linear regression relationship between GWSA and environmental variables, reducing the grid resolution of GWSA obtained from GRACE from approximately 25 km to 1 km. First, we estimate the missing values of monthly continuous terrestrial water storage anomaly (TWSA) for the period from 2003 to 2020 using interpolated multi-channel …


Applying Positive Unlabeled Learning Techniques And Using The Kullback-Leibler Divergence To Improve Geothermal Surveying Assessments, Martín Thomas Rodriguez Dec 2024

Applying Positive Unlabeled Learning Techniques And Using The Kullback-Leibler Divergence To Improve Geothermal Surveying Assessments, Martín Thomas Rodriguez

Dissertations and Theses

As we face the current climate crisis, the discovery of geothermal energy resources has the potential to greatly reduce our dependence on fossil fuels worldwide. However, the development of any new energy infrastructure is expensive and depends on the willingness of energy agencies and developers to make initial investments based on calculated risk measures. One such measure, called geothermal favorability, is the likelihood that a site has conditions favorable for geothermal systems containing recoverable energy potential. Its prediction from existing geophysical datasets proves to be a nontrivial task. The prediction of geothermal favorability can be framed as a binary classification …


Visualization Of Paleocurrents On A Web Application Using Gplates, Anjan Sapkota Dec 2024

Visualization Of Paleocurrents On A Web Application Using Gplates, Anjan Sapkota

MS in Computer Science Theses

Paleocurrents are flow directions derived from features of sedimentary rocks that reveal the direction of the current of wind or water that deposited the sediment. In 2015, Brand et al. created a global database of paleocurrents, which contains over 1,000,000 measurements worldwide: North America, South America, Australia, Great Britain, parts of Western Europe, China, Africa are fairly well represented; Antarctica, Eastern Europe, and Asia are modestly represented and Russia is poorly represented. The contribution of this thesis is a web application that uses the GPlates’ Application Programming Interface (API) to visualize global paleocurrents through time in an interactive way based …


Investigating Crystalline Rock Weathering In Distinct Climate And Ecological Settings: Insights From Shallow Seismic Refraction, Rachel Uecker Dec 2024

Investigating Crystalline Rock Weathering In Distinct Climate And Ecological Settings: Insights From Shallow Seismic Refraction, Rachel Uecker

All Dissertations

Despite decades of research, understanding the subsurface of the critical zone (CZ) remains a challenge, constrained by limited access to information at depth. Traditionally, boreholes, outcrops, soil pits, and near-surface (<1 meter) geochemical measurements provided access to and quantified CZ structure. These methods, though valuable in their detail, are spatially limited, and many landscape-scale weathering hypotheses are based on these observations. In recent years, geophysical techniques have been applied to characterize large-scale CZ structure and test the validity of existing hypotheses. This dissertation harnesses nearly 10 kilometers of seismic refraction data from diverse ecoregions across the United States to challenge prevailing assumptions about weathering patterns and CZ evolution. The objective of this work is to characterize the interpreted range of weathered materials in each ecoregion and connect them to remotely-sensed information like canopy height, elevation, slope, and aspect. To do this, this work first investigates differences in weathering at depth in a north and south-facing slope system in the Laramie Range, Wyoming. The motivation for this work came from nearly a century of soil and geochemical studies from the western United States that show a greater degree and depth of weathering on north-facing slopes when compared to south-facing slopes. Our seismic refraction data were used to show that there is not a significant difference in weathering thickness at depth between north and south-facing aspects at the study site, thus conflicting with the hypothesis that there would be. Next, the hypothesis that the depth of weathering is affected by elevation was tested in the San Jacinto Mountains in southern California. The motivation for this work came from several geochemical studies in the Sierra Nevada Mountains that show ecologically prosperous mid-elevations possess an ideal combination of temperature and precipitation to produce a greater degree and depth of weathering. Again, the seismic results from the San Jacinto Mountains provided observations that conflict with the existing hypothesis that climate conditions dominate the thickness of weathering seen in rocks. Lastly, I used seismic refraction data and topographic curvature to build a groundwater model of a watershed in the Carolina Piedmont. The results of this model reveal that seismic refraction as an application for including more realistic geometry in groundwater models can improve model calibration fits. This model is the first of its kind, and, therefore, is an important step forward in merging geophysical data with the hydrogeologic and modeling field and, with further development, can be used to explore the role of topographic and regional groundwater flow as a driver of CZ evolution.


Western Australian Soil Groups - A Diagnostic Key To Identify Soils In Western Australia (5th Edition), Paul Galloway, Dennis Van Gool, Angela Stuart-Street, Edward A. Griffin, Shahab Pathan, Noel R. Schoknecht Dec 2024

Western Australian Soil Groups - A Diagnostic Key To Identify Soils In Western Australia (5th Edition), Paul Galloway, Dennis Van Gool, Angela Stuart-Street, Edward A. Griffin, Shahab Pathan, Noel R. Schoknecht

Resource management technical reports

The aim of the Western Australian soil groups (WA soil groups) is to classify soils of Western Australia into a limited set using criteria that are easy to recognise in the field. It is a general-purpose classification with a focus on agronomic and rangeland grazing potential. The WA soil groups are designed for WA needs. It complements the Australian Soil Classification (ASC) by grouping the continuum of soils into a limited set of soil types, which simplifies soil variability for generalists, allows soil surveyors to create standardised soil-type legends for mapping products and permits further analyses of spatial data for …


River Confinement And Braiding Loss In Canterbury Region, Aotearoa New Zealand, Victoria Barlow, Peter Ashmore Dec 2024

River Confinement And Braiding Loss In Canterbury Region, Aotearoa New Zealand, Victoria Barlow, Peter Ashmore

Geography & Environment Publications

In relation to the wider concern that rivers in Aotearoa New Zealand have been narrowed by river control and land-use encroachment, and that iconic braided patterns are being lost, nine braided rivers from the Canterbury region were studied to compare river width, pattern type and braiding intensity between the mid-1900s and the present based on mapping from aerial images. Channel narrowing occurred along >90% (~490km) of the length of the rivers studied, 375km of which were historically braided. In total, the rivers narrowed by an average of 43% (48% for braided reaches). Coinciding with narrowing, braided reaches lost 1.3 channels, …


Geochemical Evidence Of Drying During The 4.2 Ka Event In Sediment Cores From The Yucatán Peninsula, Mexico, Derek K. Gibson, Jonathan Obrist-Farner, Alex Correa-Metrio, Alejandra Rodriguez-Abaunza, Carlos Castañeda-Posadas Dec 2024

Geochemical Evidence Of Drying During The 4.2 Ka Event In Sediment Cores From The Yucatán Peninsula, Mexico, Derek K. Gibson, Jonathan Obrist-Farner, Alex Correa-Metrio, Alejandra Rodriguez-Abaunza, Carlos Castañeda-Posadas

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Tropical hydroclimate variability during the Middle and Late Holocene was investigated using geochemical indicators of local-scale precipitation and evaporation preserved in sediment cores from two sites in the Mexican Yucatán Peninsula. Scanning X-Ray fluorescence spectroscopy data show generally decreasing precipitation trends during the Early and Middle Holocene. During the transition between the Middle and Late Holocene, geochemical evidence of reduced watershed erosion and increased evaporation indicate that a centennial-scale drying event impacted the region between 4.3 and 4.0 ka (kilo-anum; thousand years before present). These findings suggest that the 4.2 ka drying event, which has been previously recorded in Europe, …