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2015

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Articles 301 - 330 of 409

Full-Text Articles in Geology

Subsurface Geological Analyses Of The Berea Petroleum System In Eastern Kentucky, Julie Floyd Jan 2015

Subsurface Geological Analyses Of The Berea Petroleum System In Eastern Kentucky, Julie Floyd

Theses and Dissertations--Earth and Environmental Sciences

The Berea Sandstone is a Late Devonian, tight oil and gas reservoir that intertongues with the Bedford Shale in eastern Kentucky. In order to evaluate the Bedford-Berea interval in the subsurface, 555 well logs from the Kentucky Geological Survey’s oil and gas database were used to construct structure maps, isopach maps, and cross sections of the interval and its possible hydrocarbon source rocks. Gamma-ray logs were compared to known cores in order to separate Bedford from Berea lithologies. Maps and cross sections were compared to known basement structures to evaluate possible structural influences on the interval.

The Bedford-Berea interval is …


At-Grade Stabilization Structure Impact On Surface Water Quality Of An Agricultural Watershed, Kyle R. Minks, Matthew D. Ruark, Birl Lowery, Fred W. Madison, Dennis Frame, Todd D. Stuntebeck, Matthew J. Komiskey, George J. Kraft Jan 2015

At-Grade Stabilization Structure Impact On Surface Water Quality Of An Agricultural Watershed, Kyle R. Minks, Matthew D. Ruark, Birl Lowery, Fred W. Madison, Dennis Frame, Todd D. Stuntebeck, Matthew J. Komiskey, George J. Kraft

United States Geological Survey: Staff Publications

Decades of farming and fertilization of farm land in the unglaciated/Driftless Area (DA) of southwestern Wisconsin have resulted in the build-up of P and to some extent, N, in soils. This build-up, combined with steep topography and upper and lower elevation farming (tiered farming), exacerbates problems associated with runoff and nutrient transport in these landscapes. Use of an at-grade stabilization structure (AGSS) as an additional conservation practice to contour strip cropping and no-tillage, proved to be successful in reducing organic and sediment bound N and P within an agricultural watershed located in the DA. The research site was designed as …


Interactive Effects Of Climate Change With Nutrients, Mercury, And Freshwater Acidification On Key Taxa In The North Atlantic Landscape Conservation Cooperative Region, Alfred E. Pinkney, Charles T. Driscoll, David C. Evers, Michael J. Hooper, Jeffrey Horan, Jess W. Jones, Rebecca S. Lazarus, Harold G. Marshall, Andrew Milliken, Barnett A. Rattner, John Schmerfeld, Donald W. Sparling Jan 2015

Interactive Effects Of Climate Change With Nutrients, Mercury, And Freshwater Acidification On Key Taxa In The North Atlantic Landscape Conservation Cooperative Region, Alfred E. Pinkney, Charles T. Driscoll, David C. Evers, Michael J. Hooper, Jeffrey Horan, Jess W. Jones, Rebecca S. Lazarus, Harold G. Marshall, Andrew Milliken, Barnett A. Rattner, John Schmerfeld, Donald W. Sparling

United States Geological Survey: Staff Publications

The North Atlantic Landscape Conservation Cooperative LCC (NA LCC) is a public–private partnership that provides information to support conservation decisions that may be affected by global climate change (GCC) and other threats. The NA LCC region extends from southeast Virginia to the Canadian Maritime Provinces. Within this region, the US National Climate Assessment documented increases in air temperature, total precipitation, frequency of heavy precipitation events, and rising sea level, and predicted more drastic changes. Here, we synthesize literature on the effects of GCC interacting with selected contaminant, nutrient, and environmental processes to adversely affect natural resources within this region. Using …


Global Change And Conservation Triage On National Wildlife Refuges, Fred Johnson, Mitchell J. Eaton, Gerard Mcmahon, Raye Nilius, Michael R. Bryant, Dave Case, Julien Martin, Nathan Wood, Laura Taylor Jan 2015

Global Change And Conservation Triage On National Wildlife Refuges, Fred Johnson, Mitchell J. Eaton, Gerard Mcmahon, Raye Nilius, Michael R. Bryant, Dave Case, Julien Martin, Nathan Wood, Laura Taylor

United States Geological Survey: Staff Publications

National Wildlife Refuges (NWRs) in the United States play an important role in the adaptation of social-ecological systems to climate change, land-use change, and other global-change processes. Coastal refuges are already experiencing threats from sea-level rise and other change processes that are largely beyond their ability to influence, while at the same time facing tighter budgets and reduced staff. We engaged in workshops with NWR managers along the U.S. Atlantic coast to understand the problems they face from global-change processes and began a multidisciplinary collaboration to use decision science to help address them. We are applying a values-focused approach to …


A Bird’S- Eye View Of The Usa National Phenology Network: An Off-The-Shelf Monitoring Program, Jherime Kellerman, Caroline A. F. Enquist, Diana L. Humple, Nathaniel E. Seavy, Alyssa Rosemartin, Renée L. Cormier, Lorianne Barnett Jan 2015

A Bird’S- Eye View Of The Usa National Phenology Network: An Off-The-Shelf Monitoring Program, Jherime Kellerman, Caroline A. F. Enquist, Diana L. Humple, Nathaniel E. Seavy, Alyssa Rosemartin, Renée L. Cormier, Lorianne Barnett

United States Geological Survey: Staff Publications

Phenology is central to the biology and ecology of organisms and highly sensitive to climate. Differential responses to climate change are impacting phenological synchrony of inter- acting species, which has been implicated in the decline of migratory birds that rely on seasonal resources. However, few studies explicitly measure phenology of seasonal habitat resources on the breeding and wintering grounds and at stopover sites. While avian monitoring methods are widely standardized, methods of monitoring resource phenology can be highly variable and difficult to integrate. The USA National Phenology Network (USA- NPN) has developed standardized plant and animal phenology protocols and a …


Inference Of Hydrogeological Conditions And Source History Of Groundwater Contaminants Using 3-D Modeling And Human Health Risk Assessment, Mary Rosanna Carnagie Jan 2015

Inference Of Hydrogeological Conditions And Source History Of Groundwater Contaminants Using 3-D Modeling And Human Health Risk Assessment, Mary Rosanna Carnagie

Wayne State University Theses

This study was completed using data interpolation and human health risk modules in Spatial Analysis and Decision Assistance (SADA) software to model a 3-D time-series of 1,4-dioxane and vinyl chloride plumes and their associated health risks to infer hydrogeological conditions at the Ann Arbor Landfill site. Ordinary kriging estimates of contaminant distribution and human health risk distribution provide insight to groundwater flow direction, hydraulic conductivity distribution, and source history of contaminants at sites with groundwater contamination in a glacial aquifer system. More studies with larger datasets in glacial aquifer systems are necessary to prove these correlations, but this thesis illustrates …


Impacts Of Anthropogenic Watershed Activity On The Sedimentary Record Of Dams From The Midwestern United States: A Case Study From Michigan And Indiana, Jenna Hage-Hassan Jan 2015

Impacts Of Anthropogenic Watershed Activity On The Sedimentary Record Of Dams From The Midwestern United States: A Case Study From Michigan And Indiana, Jenna Hage-Hassan

Wayne State University Theses

Large-scale watershed land use changes, including urbanization, have resulted in accelerated soil erosion and sediment accumulation rates, which in turn have posed a threat to the longevity and productivity of a majority of the aging dams in the mid-western United States. In this study, we collected and analyzed 3 sediment cores each from two dams from the Mid-western United States: Webber Dam in Michigan and Goshen Pond Dam in Indiana. Cores were analyzed for 137Cs and 210Pb to establish chronology, as well as concentrations and isotopic composition of organic carbon and nitrogen to investigate the land use changes as preserved …


Evaluation Of Hygroscopic Soil Amendments And Natural Freeze-Thaw Cycling To Accelerate The Mechanical Breakdown Of Artifacts In Demolition Site Soils, Phillip Joseph Backers Jan 2015

Evaluation Of Hygroscopic Soil Amendments And Natural Freeze-Thaw Cycling To Accelerate The Mechanical Breakdown Of Artifacts In Demolition Site Soils, Phillip Joseph Backers

Wayne State University Theses

Many cities worldwide have areas of vacant land produced by building demolition. This open space has attracted great interest as a potential resource for green infrastructure, urban agriculture, and other purposes related to urban renewal. Unfortunately, rock-like artifacts (e.g. brick, mortar, concrete) are often present in great abundance in demolition site soils. These artifacts make the soil difficult to till, create obstacles for root penetration, and limit the soil’s water-holding capacity, infiltration and aeration. As an alternative to physical removal, this study was carried out to test the feasibility of using hygroscopic compounds as soil amendments to accelerate the mechanical …


Changes In The Geometry And Volume Of Rabots Glaciär, Sweden, 2003-2011: Recent Accelerated Volume Loss Linked To More Negative Summer Balances, Keith A. Brugger, Latysha Pankratz Jan 2015

Changes In The Geometry And Volume Of Rabots Glaciär, Sweden, 2003-2011: Recent Accelerated Volume Loss Linked To More Negative Summer Balances, Keith A. Brugger, Latysha Pankratz

Geology Publications

Terminus geometry, ice margins, and surface elevations on Rabots glaciär were measured using differential GPS during summer 2011 and compared with those similarly measured in 2003. Glacier length over the eight years decreased by ∼105 m corresponding to 13 m a−1, a rate consistent with ice recession over the last several decades. Measured changes in surface elevations show that between 2003 and 2011 the glacier’s volume decreased by ∼27.6 ± 2.6 × 106 m3, or 3.5± 0.3 × 106 m3 a−1. This compares favorably with an estimate of −28.1 ± 2.6 × 106 m3 based on a mass-balance approach. The …


Schoenophyllum Aggregatum Zone: Stratigraphic Marker For Investigations Of Mississippian Limestones In Western Kentucky, Garland R. Dever Jr., Preston Mcgrain Jan 2015

Schoenophyllum Aggregatum Zone: Stratigraphic Marker For Investigations Of Mississippian Limestones In Western Kentucky, Garland R. Dever Jr., Preston Mcgrain

Report of Investigations--KGS

Schoenophyllum aggregatum, a Mississippian colonial rugose coral, has a widespread geographic distribution and narrow stratigraphic range in the upper Ste. Genevieve Limestone of western Kentucky. This coral zone serves as a useful stratigraphic marker for commercial and geologic investigations of the extensive limestone deposits formed by the Ste. Genevieve and enclosing limestone units in the region. S. aggregatum is also present in rocks correlative with the Ste, Genevieve that occur in the Monteagle Limestone Slade Formation of south-central Kentucky and the Newman Limestone of southeastern Kentucky.


Is There Space Inside Solid Rock?, Stephen F. Greb, David C. Harris, J. Richard Bowersox Jan 2015

Is There Space Inside Solid Rock?, Stephen F. Greb, David C. Harris, J. Richard Bowersox

Map and Chart--KGS

No abstract provided.


Mapped Karst Groundwater Basins In The Hopkinsville 30 X 60 Minute Quadrangle, James C. Currens, Joseph A. Ray, Phillip W. O'Dell, Robert J. Blair Jan 2015

Mapped Karst Groundwater Basins In The Hopkinsville 30 X 60 Minute Quadrangle, James C. Currens, Joseph A. Ray, Phillip W. O'Dell, Robert J. Blair

Map and Chart--KGS

No abstract provided.


Throughfall Nutrients In A Degraded Indigenous Fagus Orientalis Forest And A Picea Abies Plantation In The Of North Of Iran, Parisa Abbasian, Pedram Attarod, Seyed Mohammad Moein Sadeghi, John T. Van Stan, Seyed M. Hojjati Jan 2015

Throughfall Nutrients In A Degraded Indigenous Fagus Orientalis Forest And A Picea Abies Plantation In The Of North Of Iran, Parisa Abbasian, Pedram Attarod, Seyed Mohammad Moein Sadeghi, John T. Van Stan, Seyed M. Hojjati

Earth, Environment & Sustainability: Faculty Publications

Aim of study: The objective of this study was to compare the quantity and quality of TF (throughfall) in an indigenous, but degraded, stand of Fagus orientalis and Picea abies plantation.

Area of study: Forests of Kelar-Dasht region located in Mazandaran province, northern Iran.

Material and Methods: TF measured by twenty collectors that were distributed randomly underneath each stand. For 21 storms sampled in 2012 (August-December) and 2013 (April-June), we analyzed pH, EC, Ca2+, Mg2+, K+, NO3-, and P of gross rainfall (GR) and TF.

Main results: Cumulative interception (I) for F. orientalis and P. abies were 114.2 mm and …


Trace Element Behavior During Coal Combustion: Insights From Cadmium And Zinc Isotope Analysis, Fotios Fouskas Jan 2015

Trace Element Behavior During Coal Combustion: Insights From Cadmium And Zinc Isotope Analysis, Fotios Fouskas

Open Access Theses & Dissertations

Due to its low cost and abundance, coal has been pervasively used in recent decades to meet large energy demands worldwide. Coal combustion provides the dominant electrical source in the U.S and produces over 100 million tons of coal combustion products (CCPs) per year domestically. The disposal/beneficial use of CCPs has the potential to release toxic trace elements, including cadmium (Cd) and zinc (Zn), into the environment. High temperature combustion of coal changes both physical states and chemical properties of Cd and Zn compounds in CCPs. Related processes such as evaporation and condensation, can lead to mass-dependent fractionation of Cd …


A Geophysical Study Of The Castle Mountain Fault System And Matanuska-Susitna Valley Near Anchorage, Alaska, Shane Michael Schinagel Jan 2015

A Geophysical Study Of The Castle Mountain Fault System And Matanuska-Susitna Valley Near Anchorage, Alaska, Shane Michael Schinagel

Open Access Theses & Dissertations

The Castle Mountain Fault (CMF) is the closest (~50 km) active fault to Anchorage, Alaska. Located within the Matanuska and Susitna (Matsu) Valleys, the CMF shows repeated, unmistakable evidence for Holocene motion. Recent geologic studies estimate that this fault is capable of producing earthquakes of magnitude 7.0 - 7.1. The Anchorage metropolitan area (which includes the Matsu Valley) contains most of Alaska's population as well as vital shipping and transportation facilities that serve much of inland Alaska. Expected magnitude >7 earthquakes pose seismic hazards to the expanding Anchorage area.

While several mapping and trenching studies have been conducted along the …


North-Central Nebraska Geology: Niobrara River Valley In Brown, Cherry, And Keya Paha Counties, R. M. Joeckel, L. M. Howard, S T. Tucker Jan 2015

North-Central Nebraska Geology: Niobrara River Valley In Brown, Cherry, And Keya Paha Counties, R. M. Joeckel, L. M. Howard, S T. Tucker

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska Statewide Groundwater-Level Monitoring Report 2015, A. R. Young, M. E. Burbach, L. M. Howard Jan 2015

Nebraska Statewide Groundwater-Level Monitoring Report 2015, A. R. Young, M. E. Burbach, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Spatial Incidence Of Adult Obesity In The State Of Alabama, Mary G. Odhiambo Jan 2015

Spatial Incidence Of Adult Obesity In The State Of Alabama, Mary G. Odhiambo

Theses

No abstract provided.


Assessing The Relative Mobility Of Submarine Landslides From Deposit Morphology And Physical Properties: An Example From Kumano Basin, Nankai Trough, Offshore Japan, Zachary T. Moore Jan 2015

Assessing The Relative Mobility Of Submarine Landslides From Deposit Morphology And Physical Properties: An Example From Kumano Basin, Nankai Trough, Offshore Japan, Zachary T. Moore

Theses and Dissertations--Earth and Environmental Sciences

A prominent landslide deposit in the Slope Basin seaward of the Megasplay Fault in the Nankai Trough was emplaced by a high-mobility landslide based on analysis of physical properties and seismic geomorphology. Slide acceleration is a critical variable that determines amplitude of slide-generated tsunami but is many times a variable with large uncertainty. In recent controlled laboratory experiments, the ratio of the shear stress to yield strength (defined as the Flow Factor) controls a wide spectrum of mass movement styles from slow, retrogressive failure to rapid, liquefied flows. Here, we apply this laboratory Flow Factor approach to a natural landslide …


Dynamic Surface Water-Groundwater Exchange In Tidal Freshwater Zones: Insights From The Christina River Basin (Delaware, Usa), Cole T. Musial Jan 2015

Dynamic Surface Water-Groundwater Exchange In Tidal Freshwater Zones: Insights From The Christina River Basin (Delaware, Usa), Cole T. Musial

Theses and Dissertations--Earth and Environmental Sciences

In coastal rivers, tides can propagate for tens to hundreds of kilometers inland beyond the saltwater line. Yet the influence of tides on river-aquifer connectivity and solute transport in tidal freshwater zones (TFZs) is largely unknown. We estimate that along the TFZ of White Clay Creek (Delaware, USA), more than 17% of river water exchanges through hyporheic and riparian storage zones due to tidal pumping alone. Additional hyporheic processes such as flow through bedforms likely contribute even more exchange. The turnover length associated with the tidal pumping process is 39 km, similar to turnover lengths for all hyporheic exchange processes …


The Environmental Effects Of Coal Fires, Trent Garrison Jan 2015

The Environmental Effects Of Coal Fires, Trent Garrison

Theses and Dissertations--Earth and Environmental Sciences

There are thousands of subterranean coal fires in the world that, because of incomplete combustion, emit a wide variety of volatile and semivolatile organic compounds to the atmosphere, water, and soil at concentrations that could pose health risks to humans and wildlife. The main goals of this study were to (1) review methods that are used to characterize physical and chemical characteristics of coal-fire sites, (2) determine relationships between gas emissions and physical and chemical characteristics of coal-fire sites, using a combination of regression and multivariate statistical methods, and (3) determine the concentrations of volatile and semivolatile organic compounds in …


Bedrock Geologic Mapping And Structural Analysis Of The Western Half Of The Petersham Quadrangle, Central Massachusetts: Further Tests Of The Model For Middle To Late Paleozoic Ductile Transpression, Vertical Extrusion, And Lateral Escape In The Northern Appalachians, Lucas P. Rohrer Jan 2015

Bedrock Geologic Mapping And Structural Analysis Of The Western Half Of The Petersham Quadrangle, Central Massachusetts: Further Tests Of The Model For Middle To Late Paleozoic Ductile Transpression, Vertical Extrusion, And Lateral Escape In The Northern Appalachians, Lucas P. Rohrer

Theses and Dissertations--Earth and Environmental Sciences

Bedrock mapping, structural analysis, and geochronology reveal the distribution of lithologies and timing of metamorphism and deformation in the western half of the Petersham 7.5’ quadrangle, western Massachusetts. Underlying lithologies are: (from west to east) the Ordovician Monson granitic orthogneiss, Silurian Rangeley migmatitic paragneiss, and Late Devonian (357 Ma) Hardwick tonalitic orthogneiss. Their tightly folded contacts strike north to south. The 361 Ma, unfoliated, strike-parallel Nichewaug quartz-diorite (10-100 m wide) intrusion spans the map area within the Rangeley. Evidence for vertical and lateral extrusion/escape of the Monson orthogneiss, as observed in the Palmer MA area, is absent. Instead, petrofabrics (foliations …


Fluvial Responses To Growth Faulting In The West Pearl River, Louisiana, Stephen A. Prosser Jan 2015

Fluvial Responses To Growth Faulting In The West Pearl River, Louisiana, Stephen A. Prosser

Theses and Dissertations--Earth and Environmental Sciences

The Pearl River Delta (PRD) in southeastern Louisiana is an actively deforming deltaic complex displaying surface and near-surface evidence of growth faulting. Active growth faults in these environments are rarely identified at the surface, in part because the downthrown blocks often experience increased rates of sediment deposition leading to an obscured and low-relief, or entirely absent, surface expression. Faulting can be expressed in fluvial systems as changes in channel gradient, which often result in coincident changes in channel sinuosity, migration rates, planform deflections, and/or ponding features within the deformed zone. The study area is focused on a meander bend of …


Katian Gssp And Carbonates Of The Simpson And Arbuckle Groups In Oklahoma, Jesse R. Carlucci, Daniel Goldman, Carlton E. Brett, Stephen R. Westrop, Stephen A. Leslie Jan 2015

Katian Gssp And Carbonates Of The Simpson And Arbuckle Groups In Oklahoma, Jesse R. Carlucci, Daniel Goldman, Carlton E. Brett, Stephen R. Westrop, Stephen A. Leslie

Department of Earth, Environment and Sustainability Faculty Publications

This guidebook was written for the 2015 International Symposium on the Ordovician System (ISOS) as a synopsis of the recent work (e.g., Goldman et al. 2007; Carlucci et al. 2014, forthcoming work for the ISOS meeting) on Ordovician-Silurian rocks of south-central and south-eastern Oklahoma. This new research and past studies (e.g., Harris 1957; Longman 1976; Longman 1982a, b; Fay et al. 1982a; Fay et al. 1982b) underscore the scientific importance of this region. The global stratotype section and point for the Katian Stage of the Upper Ordovician Series is examined on this trip. The first appearances of important graptolites, conodonts …


Geologic Map Of The Welcome Quadrangle And An Adjacent Part Of The Wells Quadrangle, Elko County, Nevada, Allen J. Mcgrew, Arthur W. Snoke Jan 2015

Geologic Map Of The Welcome Quadrangle And An Adjacent Part Of The Wells Quadrangle, Elko County, Nevada, Allen J. Mcgrew, Arthur W. Snoke

Department of Earth, Environment and Sustainability Faculty Publications

Located in central Elko County, the Welcome and adjacent part of the Wells quadrangles expose a remarkable array of critical relationships for understanding the geologic history of the State of Nevada and the interior of the southwestern U.S. Cordillera. Covering the northern end of the East Humboldt Range and adjacent Clover Valley and Clover Hill, this map includes the northern terminus of the Ruby Mountains-East Humboldt Range metamorphic core complex. The oldest rocks in the State of Nevada (the gneiss complex of Angel Lake), and Nevada’s only exposures of Archean rock, form the core of a multikilometer scale, southward-closing recumbent …


Stream Bank Erosion Trends And Sediment Contributions In A Southwestern Missouri River, Ezekiel Allen Kuehn Jan 2015

Stream Bank Erosion Trends And Sediment Contributions In A Southwestern Missouri River, Ezekiel Allen Kuehn

Graduate Theses/Dissertations

Bank erosion can be a significant source of in-stream sediment that negatively affects water quality and aquatic habitat. However, assessments of the role that eroding banks play in suspended and bed sediment supply are rarely available to managers. The purpose of this study was to quantify bank erosion rates for a 7 km conservation easement the James River in southwest Missouri to evaluate the annual contributions of bank sediment to the channel. The objectives were to: (1) monitor an eroding 260 m bank to better understand short-term, reach scale bank erosion rates; (2) determine historical rates of bank erosion for …


Patterns And Processes Of Salt Efflorescences In The Mcmurdo Region, Antarctica, Kelsey M. Bisson, Kathleen A. Welch, Susan A. Welch, Julia Meyer Sheets, W. Berry Lyons, Joseph S. Levy, Andrew G. Fountain Jan 2015

Patterns And Processes Of Salt Efflorescences In The Mcmurdo Region, Antarctica, Kelsey M. Bisson, Kathleen A. Welch, Susan A. Welch, Julia Meyer Sheets, W. Berry Lyons, Joseph S. Levy, Andrew G. Fountain

Geology Faculty Publications and Presentations

Evaporite salts are abundant around the McMurdo region, Antarctica (~78°S) due to very low precipitation, low relative humidity, and limited overland flow. Hygroscopic salts in the McMurdo Dry Valleys (MDVs) are preferentially formed in locations where liquid water is present in the austral summer, including along ephemeral streams, ice-covered lake boundaries, or shallow groundwater tracks. In this study, we collected salts from the Miers, Garwood, and Taylor Valleys on the Antarctic continent, as well as around McMurdo Station on Ross Island in close proximity to water sources with the goal of understanding salt geochemistry in relationship to the hydrology of …


Theoretical Foundation Of Cyclostationary Eof Analysis For Geophysical And Climatic Variables: Concepts And Examples, Kwang-Yul Kim, Benjamin Hamlington, Hanna Na Jan 2015

Theoretical Foundation Of Cyclostationary Eof Analysis For Geophysical And Climatic Variables: Concepts And Examples, Kwang-Yul Kim, Benjamin Hamlington, Hanna Na

CCPO Publications

Natural variability is an essential component of observations of all geophysical and climate variables. In principal component analysis (PCA), also called empirical orthogonal function (EOF) analysis, a set of orthogonal eigenfunctions is found from a spatial covariance function. These empirical basis functions often lend useful insights into physical processes in the data and serve as a useful tool for developing statistical methods. The underlying assumption in PCA is the stationarity of the data analyzed; that is, the covariance function does not depend on the origin of time. The stationarity assumption is often not justifiable for geophysical and climate variables even …


A Joint Receiver Function And Gravity Study Of Crustal Structure Beneath The Incipient Okavango Rift, Botswana, Youqiang Yu, Kelly H. Liu, Cory A. Reed, Moikwathai Moidaki, Kevin Mickus, Estella A. Aetkwana, Stephen S. Gao Jan 2015

A Joint Receiver Function And Gravity Study Of Crustal Structure Beneath The Incipient Okavango Rift, Botswana, Youqiang Yu, Kelly H. Liu, Cory A. Reed, Moikwathai Moidaki, Kevin Mickus, Estella A. Aetkwana, Stephen S. Gao

College of Natural and Applied Sciences

Rifting incorporates the fundamental processes concerning the breakup of continental lithosphere and plays a significant role in the formation and evolution of sedimentary basins. In order to decipher the characteristics of rifting at its earliest stage, we conduct the first teleseismic crustal study of one of the world's youngest continental rifts, the Okavango Rift Zone (ORZ), where the magma has not yet breached the surface. Results from receiver function stacking and gravity modeling indicate that the crust/mantle boundary beneath the ORZ is uplifted by 4-5 km, and the initiation of the ORZ is closely related to lithospheric stretching. Possible decompression …


Interplay Of Porous Media And Fracture Stimulation In Sedimentary Enhanced Geothermal Systems : Red River Formation, Williston Basin, North Dakota, Caitlyn M. Hartig Jan 2015

Interplay Of Porous Media And Fracture Stimulation In Sedimentary Enhanced Geothermal Systems : Red River Formation, Williston Basin, North Dakota, Caitlyn M. Hartig

Theses and Dissertations

Fracture stimulated enhanced geothermal systems (EGS) can be installed in both crystalline rocks and sedimentary basins. The Red River Formation (Ordovician), which lies between 3.6 and 4.2 km depth in the Williston Basin, is a viable site for installation of sedimentary EGS (SEGS). SEGS is possible there because temperatures in the formation surpass 140° Celsius and the permeability is 0.1-38 mD; fracture stimulation can be utilized to improve performance. The main objectives of this project were 1) to determine the spatial variation of the intrinsic properties of the Red River Formation across the study area, and 2) to understand the …