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Full-Text Articles in Earth Sciences

Permeability Prediction In Rocks Experiencing Mineral Precipitation And Dissolution: A Numerical Study, Qifei Niu, Chi Zhang Apr 2019

Permeability Prediction In Rocks Experiencing Mineral Precipitation And Dissolution: A Numerical Study, Qifei Niu, Chi Zhang

Geosciences Faculty Publications and Presentations

In this study, we focus on the electrical tortuosity-based permeability model k = reff2/8F (reff is an effective pore size, and F is the formation factor) and analyze its applicability to rocks experiencing mineral precipitation and dissolution. Two limiting cases of advection-dominated water-rock reactions are simulated, that is, the reaction-limited and transport-limited cases. At the pore scale, the two precipitation/dissolution patterns are simulated with a geometrical model and a phenomenological model. The fluid and electric flows in the rocks are simulated by directly solving the linear Stokes equation and Laplace equation on the representative …


Measurements Of Geomagnetic Declination (1685-1910) Using Land Surveys, Lidar, And Stone Walls, John W. Delano Phd Apr 2019

Measurements Of Geomagnetic Declination (1685-1910) Using Land Surveys, Lidar, And Stone Walls, John W. Delano Phd

Atmospheric and Environmental Science Faculty Scholarship

Nearly 1200 kilometers of boundaries surveyed in 1685-1910, upon which stone walls were subsequently built, were measured using high-resolution LiDAR (Light Detection and Ranging) in the northeastern United States (New Hampshire and New York). The geomagnetic declinations at the time of the original land surveys of those stone wall-defined boundaries have been determined and compared with (i) current geophysical models (i.e., gufm1, IGRF12; United States Historical Declinations-USHD), and (ii) measured declinations (Bauer, 1902). With the exception of lower declinations (i.e., 1.5° eastward) in 1775-1810, the results of this study are in good agreement with gufm1 and IGRF12 geomagnetic declinations. This …


Raspberry Pi Cluster For Parallel And Distributed Computing, Ngoc Ha Apr 2019

Raspberry Pi Cluster For Parallel And Distributed Computing, Ngoc Ha

Graduate Theses & Non-Theses

Parallel and distributed computing have become an essential part of the ‘Big Data’ processing and analysis, especially for geophysical applications. The main goal of this project was to build a 4-node distributed computing cluster system using the Raspberry Pi single-board computers for educational and research purposes. After assembling together the system, a standard test was performed to check the system functionality. A Monte Carlo simulation to calculate π (pi) was used to demonstrate the advantages and drawbacks of parallelization and distribution of tasks and data within the cluster. Challenges encountered during installation of the software and testing phase, and their …


Fault Mapping In 3d Seismic Reflection Data Using Seismic Attributes And Velocity Anisotropy: Example From West Virginia, Megan Valdez Apr 2019

Fault Mapping In 3d Seismic Reflection Data Using Seismic Attributes And Velocity Anisotropy: Example From West Virginia, Megan Valdez

Graduate Theses & Non-Theses

Fracture characterization is highly important in the oil and gas industry. Knowing the location of fractures allows for the assessment of reservoir quality, aids in well placement and planning, and helps identify locations of possible traps. Fracture locations can be determined using seismic data for attribute calculations and anisotropy analysis. Attribute calculations, such as coherence and curvature, identify subtle changes in the dataset that conventional seismic data interpretation might overlook. Anisotropy analysis looks at directionally dependent variations in the wave propagation velocity. Fractures slow the propagation velocity of a wave if the fractures are perpendicular to the wave direction. A …


Results Of The March 2019 Geophysical Survey Near Richardton, North Dakota, University Of North Dakota. Energy And Environmental Research Center Apr 2019

Results Of The March 2019 Geophysical Survey Near Richardton, North Dakota, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet describing the results of a March 2019 geophysical survey near Richardton, North Dakota, conducted by the Energy & Environmental Research Center and funded in part by the U.S. Department of Energy. This was part of the Red Trail Energy carbon capture and storage (CCS) research effort. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Transitional Granulite-Facies Mafic Xenoliths In The 2.8 Ga Trondjhemite-Tonalite-Granodiorite (Ttg) Gneisses Of The Eastern Beartooth Mountains, Mt/Wy: Evidence For Variable Fluid Interactions, Andrew W. Osborne Apr 2019

Transitional Granulite-Facies Mafic Xenoliths In The 2.8 Ga Trondjhemite-Tonalite-Granodiorite (Ttg) Gneisses Of The Eastern Beartooth Mountains, Mt/Wy: Evidence For Variable Fluid Interactions, Andrew W. Osborne

Honors Capstones

No abstract provided.


Completed Geophysical Survey Near Richardton, N.D., University Of North Dakota. Energy And Environmental Research Center Apr 2019

Completed Geophysical Survey Near Richardton, N.D., University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about an intended geophysical survey near Richardton, North Dakota. Describes the survey’s goal of evaluating the area’s feasibility as a CO2 storage site, as part of the Red Trail Energy carbon capture and storage research effort. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Submarine Groundwater Discharge In The Southern Chesapeake Bay: Constraints From Numerical Models, Charles Louis Carlson Apr 2019

Submarine Groundwater Discharge In The Southern Chesapeake Bay: Constraints From Numerical Models, Charles Louis Carlson

OES Theses and Dissertations

Terrestrial and oceanic forces drive fluid flow within the coastal zone to produce submarine groundwater discharge (SGD). Groundwater flowing from the seabed serves as a significant pathway for contaminants and nutrients, producing an active biogeochemical reaction zone. In order to quantify the importance of SGD in geochemical and hydrologic budgets for the lower Chesapeake Bay, three coastal Virginia transects (southern Eastern Shore, Lafayette River, and Ocean View beach) with different topographic gradients were modeled using similar boundary conditions and consistent treatment of hydrogeologic layers. A sensitivity study was performed on the variables of recharge rate, seawater density, and hydraulic permeability. …


Structure Beneath The Northern Los Angeles Basins From Teleseismic Receiver Functions, Guibao Liu Mar 2019

Structure Beneath The Northern Los Angeles Basins From Teleseismic Receiver Functions, Guibao Liu

LSU Master's Theses

This thesis presents part of the work published in Liu et al. (2018).

The Los Angeles area is at high risk of seismic amplification due to its location on top of sedimentary basins. It is very important to obtain accurate information on the crustal structure, in particular, the basin structure of the northern basins, in order to estimate the resulting ground motion and earthquake hazards due to a large San Andreas fault earthquake. In the Liu et al. (2018) study, we image the crustal structure beneath the northern basins using a densely spaced, autonomous 3-component seismometer array in the urban …


Full-Waveform Inversion Of Common-Offset Ground Penetrating Radar (Gpr) Data, Sajad Jazayeri Mar 2019

Full-Waveform Inversion Of Common-Offset Ground Penetrating Radar (Gpr) Data, Sajad Jazayeri

USF Tampa Graduate Theses and Dissertations

Maintenance of aging buried infrastructure and reinforced concrete are critical issues in the United States. Inexpensive non-destructive techniques for mapping and imaging infrastructure and defects are an integral component of maintenance. Ground penetrating radar (GPR) is a widely-used non-destructive tool for locating buried infrastructure and for imaging rebar and other features of interest to civil engineers. Conventional acquisition and interpretation of GPR profiles is based on the arrival times of strong reflected/diffracted returns, and qualitative interpretation of return amplitudes. Features are thereby generally well located, but their material properties are only qualitatively assessed. For example, in the typical imaging of …


Geophysical Analysis Of The Midcontinent Rift’S Subsurface Structure In Southeastern Nebraska, Patrick Szopinski Mar 2019

Geophysical Analysis Of The Midcontinent Rift’S Subsurface Structure In Southeastern Nebraska, Patrick Szopinski

Honors Program: Senior Projects (Public)

The Midcontinent Rift System (MCRS) is a 1.1 billion-year-old failed rift system that spans much of the North American continental interior. The MCRS is exposed at Lake Superior and is buried in the subsurface along its southwest-extending arm through southeastern Nebraska. Due to the presence of buried volcanic rocks, the MCRS has characteristic highly-pronounced potential field anomalies (gravity and magnetic). Despite these large anomalies, not much is known about the subsurface faulting associated with the rift zone in the Midwest. The goal of this project is to attempt to use integrated analysis of collected geophysical data from multiple methods to …


Reflector Dip Trends In Seismic Sh-Wave Imaging Of A Modern Lower Mississippi River Point Bar, Adam Gostic Mar 2019

Reflector Dip Trends In Seismic Sh-Wave Imaging Of A Modern Lower Mississippi River Point Bar, Adam Gostic

LSU Master's Theses

Various studies of ancient point bars have noted that a relationship can be observed between the dip angle and grain size of point bar lateral accretion deposits, with the most mud-rich deposits tending to exhibit the greatest dip. No analysis and only cursory explanations for this relationship have been provided. Additionally, buried mid-channel bars are absent from typical models of point bar architecture.

We successfully image the architecture of late-stage point bar deposits with a near surface 2D seismic SH-wave reflection survey and generate an SH-wave velocity model of the subsurface in the study area in order to interpret the …


Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski Mar 2019

Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski

Engagement & Service-Learning Summit

No abstract provided.


High-Resolution Record Reveals Climate-Driven Environmental And Sedimentary Changes In An Active Rift, Lisa C. Mcneill, Donna J. Shillington, Gareth D. O. Carter, Jeremy D. Everest, Robert L. Gawthorpe, Clint Miller, Marcie P. Phillips, Richard E. Ll. Collier, Aleksandra Cvetkoska, Gino De Gelder, Paula Diz, Mai-Linh Doan, Mary Ford, Maria Geraga, Jack Gillespie, Romain Hemelsdael, Emilio Herrero-Bervera, Mohammad Ismaiel, Liliane Janikian, Katerina Kouli, Erwan Le Ber, Shunli Li, Marco Maffione, Carol Mahoney, Malka L. Machlus, Georgios Michas, Casey W. Nixon, Sabire Asli Oflaz, Abah P. Omale, Kostas Panagiotopoulos, Sofia Pechlivanidou, Simone Sauer, Joana Seguin, Spyros Sergiou, Natalia V. Zakharova, Sophie Green Feb 2019

High-Resolution Record Reveals Climate-Driven Environmental And Sedimentary Changes In An Active Rift, Lisa C. Mcneill, Donna J. Shillington, Gareth D. O. Carter, Jeremy D. Everest, Robert L. Gawthorpe, Clint Miller, Marcie P. Phillips, Richard E. Ll. Collier, Aleksandra Cvetkoska, Gino De Gelder, Paula Diz, Mai-Linh Doan, Mary Ford, Maria Geraga, Jack Gillespie, Romain Hemelsdael, Emilio Herrero-Bervera, Mohammad Ismaiel, Liliane Janikian, Katerina Kouli, Erwan Le Ber, Shunli Li, Marco Maffione, Carol Mahoney, Malka L. Machlus, Georgios Michas, Casey W. Nixon, Sabire Asli Oflaz, Abah P. Omale, Kostas Panagiotopoulos, Sofia Pechlivanidou, Simone Sauer, Joana Seguin, Spyros Sergiou, Natalia V. Zakharova, Sophie Green

Publications and Research

Young rifts are shaped by combined tectonic and surface processes and climate, yet few records exist to evaluate the interplay of these processes over an extended period of early rift-basin development. Here, we present the longest and highest resolution record of sediment flux and paleoenvinronmental changes when a young rift connects to the global concerns. New results from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift shows 10s-100s of kyr cyclic variations in basin paleoenvironment as eustatic sea level fluctuated with respect to sills bounding this semi-isolated basin, and reveal substantial corresponding changes in the volume and …


A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak Feb 2019

A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak

Computer Information Technology Faculty Publications

The realization of Internet of Underground Things (IOUT) relies on the establishment of reliable communication links, where the antenna becomes a major design component due to the significant impacts of soil. In this paper, a theoretical model is developed to capture the impacts of change of soil moisture on the return loss, resonant frequency, and bandwidth of a buried dipole antenna. Experiments are conducted in silty clay loam, sandy, and silt loam soil, to characterize the effects of soil, in an indoor testbed and field testbeds. It is shown that at subsurface burial depths (0.1-0.4m), change in soil moisture impacts …


Timing And Rates Of Events In The Generic Volcanic Earthquake Swarm Model, Tianyu Rong Feb 2019

Timing And Rates Of Events In The Generic Volcanic Earthquake Swarm Model, Tianyu Rong

USF Tampa Graduate Theses and Dissertations

In this thesis I combine data from 29 volcanic earthquake swarms that follow the pattern predicted by the Generic Volcanic Earthquake Swarm Model (GVESM; Benoit and McNutt, 1996) to investigate whether the relative timing of various parameters of pre-eruptive volcanic earthquake swarms could be used to forecast the time of an impending eruption. Based on the analysis of seismic unrest preceding many eruptions, the GVESM suggests that it is common to see an increase first in high-frequency earthquakes, then low-frequency earthquakes, then the onset of volcanic tremor. While this pattern is useful to volcano-seismologists, the relative timing and durations of …


Examining Interactions Between And Among Predictors Of Net Ecosystem Exchange: A Machine Learning Approach In A Semi-Arid Landscape, Qingtao Zhou, Aaron Fellows, Gerald N. Flerchinger, Alejandro N. Flores Feb 2019

Examining Interactions Between And Among Predictors Of Net Ecosystem Exchange: A Machine Learning Approach In A Semi-Arid Landscape, Qingtao Zhou, Aaron Fellows, Gerald N. Flerchinger, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

Net ecosystem exchange (NEE) is an essential climate indicator of the direction and magnitude of carbon dioxide (CO2) transfer between land surfaces and the atmosphere. Improved estimates of NEE can serve to better constrain spatiotemporal characteristics of terrestrial carbon fluxes, improve verification of land models, and advance monitoring of Earth’s terrestrial ecosystems. Spatiotemporal NEE information developed by combining ground-based flux tower observations and spatiotemporal remote sensing datasets are of potential value in benchmarking land models. We apply a machine learning approach (Random Forest (RF)) to develop spatiotemporally varying NEE estimates using observations from a flux tower and several …


Hillslope Hydrology In Global Change Research And Earth System Modeling, A. Flores, J. Mcnamara Feb 2019

Hillslope Hydrology In Global Change Research And Earth System Modeling, A. Flores, J. Mcnamara

Geosciences Faculty Publications and Presentations

Earth System Models (ESMs) are essential tools for understanding and predicting global change, but they cannot explicitly resolve hillslope‐scale terrain structures that fundamentally organize water, energy, and biogeochemical stores and fluxes at subgrid scales. Here we bring together hydrologists, Critical Zone scientists, and ESM developers, to explore how hillslope structures may modulate ESM grid‐level water, energy, and biogeochemical fluxes. In contrast to the one‐dimensional (1‐D), 2‐ to 3‐m deep, and free‐draining soil hydrology in most ESM land models, we hypothesize that 3‐D, lateral ridge‐to‐valley flow through shallow and deep paths and insolation contrasts between sunny and shady slopes are the …


Including Variability Across Climate Change Projections In Assessing Impacts On Water Resources In An Intensively Managed Landscape, Bangshuai Han, Shawn G. Benner, Alejandro N. Flores Feb 2019

Including Variability Across Climate Change Projections In Assessing Impacts On Water Resources In An Intensively Managed Landscape, Bangshuai Han, Shawn G. Benner, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

In intensively managed watersheds, water scarcity is a product of interactions between complex biophysical processes and human activities. Understanding how intensively managed watersheds respond to climate change requires modeling these coupled processes. One challenge in assessing the response of these watersheds to climate change lies in adequately capturing the trends and variability of future climates. Here we combine a stochastic weather generator together with future projections of climate change to efficiently create a large ensemble of daily weather for three climate scenarios, reflecting recent past and two future climate scenarios. With a previously developed model that captures rainfall-runoff processes and …


Probability Of Streamflow Permanence Model (Prosper): A Spatially Continuous Model Of Annual Streamflow Permanence Throughout The Pacific Northwest, K. E. Kaiser Jan 2019

Probability Of Streamflow Permanence Model (Prosper): A Spatially Continuous Model Of Annual Streamflow Permanence Throughout The Pacific Northwest, K. E. Kaiser

Geosciences Faculty Publications and Presentations

The U.S. Geological Survey (USGS) has developed the PRObability of Streamflow PERmanence (PROSPER) model, a GIS raster-based empirical model that provides streamflow permanence probabilities (probabilistic predictions) of a stream channel having year-round flow for any unregulated and minimallyimpaired stream channel in the Pacific Northwest region, U.S. The model provides annual predictions for 2004–2016 at a 30-m spatial resolution based on monthly or annually updated values of climatic conditions and static physiographic variables associated with the upstream basin. Predictions correspond to any pixel on the channel network consistent with the medium resolution National Hydrography Dataset channel network stream grid. Total annual …


Late Permian And Early Triassic Conchostracans From The Babii Kamen Section (Kuznetsk Coal Basin), V. I. Davydov, V. V. Zharinova, V. V. Silantiev Jan 2019

Late Permian And Early Triassic Conchostracans From The Babii Kamen Section (Kuznetsk Coal Basin), V. I. Davydov, V. V. Zharinova, V. V. Silantiev

Geosciences Faculty Publications and Presentations

The Late Permian and Early Triassic conchostracans from the Babii Kamen section (Western Siberia) were studied. The conchostracans were collected from the section during the field work in 2015–2018. It was found that the conchostracans from the Babii Kamen section are characterized by a rather high taxonomical diversity: we identified five Late Permian conchostracan species (Pseudestheria novacastrensis (Mitchell, 1927), Cornia papillaria (Lutkevich, 1937), Megasitum harmonicum Novojilov, 1970, Megasitum lopokolense Novojilov, 1970, and Echinolimnadia mattoxi Novojilov, 1965) and two Early Triassic species (Concherisma tomensis Novojilov, 1958, Cyclotunguzites gutta (Lutkevich, 1938). The discovered conchostracan species occur frequently in the …


An Update Of Seismic Monitoring And Research In The Vicinity Of The Paducah Gaseous Diffusion Plant: January 2013–December 2017, Zhenming Wang, Edward W. Woolery, N. Seth Carpenter Jan 2019

An Update Of Seismic Monitoring And Research In The Vicinity Of The Paducah Gaseous Diffusion Plant: January 2013–December 2017, Zhenming Wang, Edward W. Woolery, N. Seth Carpenter

Report of Investigations--KGS

From January 2013 to December 2017, the Kentucky Geological Survey monitored earthquakes and conducted research on seismic hazards in the vicinity of the Paducah Gaseous Diffusion Plant, a former uranium enrichment facility, in western Kentucky. Fifteen earthquakes with magnitude greater than 3.0 occurred in the area during this period, and data were collected from the Central U.S. Seismic Observatory and the vertical seismic array at the gaseous diffusion plant. This monitoring improved our understanding of seismic-wave propagation through thick sediments and ground-motion site effects, as well as fault locations in the New Madrid Seismic Zone, ground-motion attenuation, and seismic-hazard assessment. …


Applying Cloud-Based Computing And Emerging Remote Sensing Technologies To Inform Land Management Decisions, Monica Vermillion, Josh Enterkine, Lucas Spaete, Nancy Glenn Jan 2019

Applying Cloud-Based Computing And Emerging Remote Sensing Technologies To Inform Land Management Decisions, Monica Vermillion, Josh Enterkine, Lucas Spaete, Nancy Glenn

Geosciences Faculty Publications and Presentations

Who: Boise State University and Mountain Home Air Force Base

What: Creating a species level classification map through the use of Google Earth Engine (GEE), a cloud-based computing platform, to map invasive species

When: In-situ data collected in Summer 2018, a continuation of data collected in Summer 2016. Classification was created in Fall 2018. Unmanned aerial vehicles (UAV) flights in August 2018.

Where: Mountain Home Air Force Base (MHAFB) in southwest Idaho, ecosystem is in the Great Basin Range (GBR)

Why: The introduction of exotic species like cheatgrass (Bromus tectorum) has drastically altered the fire cycle of the …


The Undeniable Attraction Of Lunar Swirls, Dany Waller Jan 2019

The Undeniable Attraction Of Lunar Swirls, Dany Waller

Posters-at-the-Capitol Presentations

Lunar swirls are complex patterns on the Moon with distinct brightness signatures and magnetic characteristics. Current research has suggested that the formation of lunar swirls relies on local magnetic fields to shield impinging solar wind, based on a shift in electromagnetic wavelength peaks related to solar radiation and space weathering. Our research combined recent models and methods to characterize these anomalies at the surface of the Moon, exploring the effects of field strength and position. We have produced a high resolution map of a famous swirl named Reiner Gamma using magnetic dipole modeling. These maps and models are considered when …


Seismic Monitoring And Baseline Microseismicity In The Rome Trough, Eastern Kentucky, N. Seth Carpenter, Andrew S. Holcomb, Zhenming Wang, John B. Hickman, Edward W. Woolery Jan 2019

Seismic Monitoring And Baseline Microseismicity In The Rome Trough, Eastern Kentucky, N. Seth Carpenter, Andrew S. Holcomb, Zhenming Wang, John B. Hickman, Edward W. Woolery

Report of Investigations--KGS

In the central and eastern United States, felt earthquakes likely triggered by fluid injection from oil and gas production or wastewater disposal have dramatically increased in frequency since the onset of the unconventional shale gas and oil boom. In the Rome Trough of eastern Kentucky, fracture stimulations and wastewater injection are ongoing and occur near areas of historical seismic activity. Unlike in surrounding and nearby states (Ohio, West Virginia, and Arkansas), in Kentucky, no seismic events related to subsurface fluid injections have been reported as felt or detected by regional seismic networks, including the Kentucky Seismic and Strong-Motion Network.

Oil …


Receiver Function Investigations Of Mantle Transition Zone And Crustal Structure In East Africa And Northeast Asia, Muchen Sun Jan 2019

Receiver Function Investigations Of Mantle Transition Zone And Crustal Structure In East Africa And Northeast Asia, Muchen Sun

Doctoral Dissertations

"In spite of numerous geophysical studies have been conducted in East Africa and Northeast Asia, the structure and evolution of the crust, upper mantle, and the mantle transition zone (MTZ) are still controversial. The MTZ discontinuities beneath the study area are imaged by stacking an unprecedented volume of receiver functions (RFs). The normal MTZ thickness beneath the Western Branch of the EARS and Tanzania Craton indicates the absence of present-day thermal upwelling from the lower mantle. In contrast, beneath the Eastern Branch, a significant MTZ thinning reveals the existence of thermal upwelling from either the upper MTZ or the lower …


Possible Hydroseismic Triggering For Small Earthquakes Occurring Within The Fox River Valley, Northeastern Illinois, James Benco Jan 2019

Possible Hydroseismic Triggering For Small Earthquakes Occurring Within The Fox River Valley, Northeastern Illinois, James Benco

Graduate Research Theses & Dissertations

In February, 2010 the town of Lily Lake experienced a magnitude 3.8 earthquake. This was followed by small earthquakes of magnitude 2-3 in the same general area in 2012 (McHenry), 2013 (Campton Hills) and 2015 (Lake of the Hills). Seismicity within this region is poorly understood. The Fox River Valley (here defined as the Fox River drainage basin) area is not historically seismically active, nor does it lie above a mapped fault. This study examines the timing of these earthquakes and the hypothesis they were triggered by pore-pressure increases at depth from large rainfall events several months earlier. A pressure …


Mineral Exploration And Sustainable Development: A Case Study In The Republic Of South Sudan, Cosmas Pitia Kujjo Jan 2019

Mineral Exploration And Sustainable Development: A Case Study In The Republic Of South Sudan, Cosmas Pitia Kujjo

Theses and Dissertations--Earth and Environmental Sciences

South Sudan, a new country formed in 2011, has been planning to develop its mineral sector by allocating exploration licenses to investors. This decision requires preliminary knowledge of geology and mineral occurrences, both of which are unavailable because the country has been engaged in a civil war for more than 50 years. Exploration of mineral resources in South Sudan has lagged behind its petroleum industry, except for artisanal gold mining, which is practiced intermittently by local communities. Freely available satellite gravity and remote-sensing data were used to map the basement architecture as well as zones of hydrothermal alteration in the …


Impacts Of Basin-Scale Climate Modes On Coastal Sea Level: A Review, Weiqing Han, Detlef Stammer, Philip Thompson, Tal Ezer, Hindu Palanisamy, Xuebin Zhang, Catia M. Domingues, Lei Zhang, Dongliang Yuan Jan 2019

Impacts Of Basin-Scale Climate Modes On Coastal Sea Level: A Review, Weiqing Han, Detlef Stammer, Philip Thompson, Tal Ezer, Hindu Palanisamy, Xuebin Zhang, Catia M. Domingues, Lei Zhang, Dongliang Yuan

CCPO Publications

Global sea level rise (SLR) associated with a warming climate exerts significant stress on coastal societies and low-lying island regions. The rates of coastal SLR observed in the past few decades, however, have large spatial and temporal differences from the global mean, which to a large part have been attributed to basin-scale climate modes. In this paper, we review our current state of knowledge about climate modes’ impacts on coastal sea level variability from interannual-to-multidecadal timescales. Relevant climate modes, their impacts and associated driving mechanisms through both remote and local processes are elaborated separately for the Pacific, Indian and Atlantic …


Use Of Seismic Refraction In Determining Rock Mass Anisotropy, Mohammad Najmush Sakib Oyan Jan 2019

Use Of Seismic Refraction In Determining Rock Mass Anisotropy, Mohammad Najmush Sakib Oyan

Electronic Theses and Dissertations

Seismic refraction is a popular method used by geological/geotechnical engineers to understand subsurface conditions. This method along with information collected from borings produce a realistic image of the ground beneath us. The goal of this study is to define and test a set of procedures to use seismic refraction alone to create high quality images of subsurface conditions. The focus is on areas with several meters of soil overlain by bedrock. The application of these procedures will minimize construction costs by eliminating the need for multiple boreholes. The results show that two important criteria must be met for successful application …