Geophysics and Seismology Commons^™

Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese

Theses and Dissertations--Earth and Environmental Sciences

Terrestrial paleoseismological records along the Teton fault have historically indicated two-to-three major post-Pinedale (~14 ka) earthquake events, leaving an unresolved 6-9 m offset along the modern scarp. Recent studies of Jenny Lake have augmented this record, but the triggering mechanism is still equivocal until new paleo-earthquake records are developed. The earthquake record of the Teton fault is complicated by quiescence from ~5 ka to present, demonstrating the need for additional paleoseismic investigations. Compressed, high-intensity radar pulse (CHIRP) reflection data from Jackson Lake indicates multiple potentially seismically-induced mass transport deposits (MTDs). At least six MTD Groups representing chronostratigraphic intervals were interpreted …

Magnetic Anomaly Data Products Of The Central And Eastern United States, Dhananjay Ravat

Earth and Environmental Sciences Research Data

This data set contains Central and Eastern U.S. Magnetic Anomaly, DRTP, Tilt Derivative, and Analytic Signal Amplitude Products ultimately derived from Ravat, D., Finn, C., Hill, P., Kucks, R., Phillips, J., Blakely, R., Bouligand, C., Sabaka, T., Elshayat, A., Aref, A., and Elawadi, E., 2009, A preliminary, full spectrum, magnetic anomaly grid of the United States with improved long wavelengths for studying continental dynamics--A website for distribution of data: U.S. Geological Survey Open- File Report 2009–1258, 2 p.

Discovery Of The Middle Mantle Transition Zone (Mmtz) And Its Geodynamic Significance, Yuping Wang

Theses and Dissertations--Earth and Environmental Sciences

Global mantle discontinuities and mantle transition zones are crucial to the earth’s evolution. By employing K-Means clustering, which belongs to cluster analysis in machine learning (ML), on shear velocity variation data, we generate heterogeneity percentage profiles for three different global tomographic models (Models S362WMANI+M, SEMUCB-WM1, and S40RTS). Key cluster percentage shifts, which are observed at around 400 km, 650 km, 1050 km, 1500 km, and 2700 km, suggest global mantle discontinuities at corresponding depths. All profiles also indicate a global discontinuity in the lower mantle between 2200 km and 2600 km. The middle mantle transition zone (MMTZ), bounded between 1050 …

Analyzing Slab Holes In Subduction Zones And Their Impacts Through Numerical Simulations, Taylor M. Arrowood

Theses and Dissertations--Earth and Environmental Sciences

Subduction zones form as higher density oceanic lithosphere is forced beneath an over-riding, lower density, continental or oceanic plate; a process driven by contrasts in buoyancy throughout this system. We seek to explore subduction zones in which the subducting lithosphere is discontinuous after passing through the trench, forming a slab gap. The main research objective is to determine the effect of slab gaps on surface topography in a subduction-related orogen and asthenospheric flow into the mantle wedge using two and three-dimensional numerical mechanical models. We obtain results from 24+ models that suggest a connection between slab gaps/holes and the magnitude …

Admittance Modeling For Elastic Thickness Across The Mars Crustal Dichotomy Boundary, Aspen Davis

Theses and Dissertations--Earth and Environmental Sciences

We use a Bouguer mass-sheet approximation for spectral admittance and correlation modeling to estimate elastic thickness, crustal thickness, crustal density, and load density across the Mars crustal dichotomy boundary near the landing site of NASA’s InSight Lander. We derive and constrain the parameter ranges using RMS misfit between the observed and theoretical admittance and their error bars. Spherical cap windows of 15° (900 km) radius are used to study 15 locations in the Northern Lowlands, the Southern Highlands and near and on the boundary which suggest distinct, but not sharp, difference in lithospheric properties. Elastic thickness estimates range generally between …

Geophysical Techniques Used For The Analysis And Prediction Of Soil Strength And Mechanical Behavior, Matthew A. Hurley

Theses and Dissertations--Civil Engineering

Determining soil properties involves extensive laboratory testing of samples at discrete timing and location. Non-destructive analysis methods, such as electrical and seismic, presents alternatives to means of gathering soil properties accompanied with increased flexibility due to spatial and temporal applications. This research examined the ability of seismic wave data to predict soil behavior such as stress-strain and pore pressures using a modified version of Duncan and Chang (1970). Friction angle predictions were also analyzed using shear wave velocity and a modified form of the Santos and Gomez-Correria (2001) equation. This research also analyzed the use of electrical data to predict …

Integrated Geophysical Investigation Of Near-Surface Faults - Sassafras Ridge, New Madrid Seismic Zone, Usa, Cooper Cearley

Theses and Dissertations--Earth and Environmental Sciences

The New Madrid Seismic Zone (NMSZ) is a large source of seismic hazard within the central and eastern United States. Seismogenic source parameters such as active fault location, slip rate, total displacement, and strain accommodation is poorly constrained due to the masking effect of the Mississippi Embayment sediment and agricultural practices on structures and surface expressions. Consequently, noninvasive geologic and geophysical investigation of the subsurface is needed to characterize seismogenic sources. Recent investigation of the Reelfoot Fault found that there is a strain accommodation enigma between the dextral offset at seismogenic depth versus the surface expression, Reelfoot Scarp. This strain …

An Update Of Seismic Monitoring And Research In The Vicinity Of The Paducah Gaseous Diffusion Plant: January 2018–December 2019, Zhenming Wang, N. Seth Carpenter, Edward W. Woolery

Report of Investigations--KGS

From January 2018 to December 2019, 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 McCracken County, western Kentucky. Six hundred forty-four earthquakes with magnitude between 0.5 and 3.7 were recorded in the area during this period. Research focused on the influence of the thick sediments on earthquake ground motion, the so-called site response, through theoretical and data analysis of borehole seismic records. Our research has shown that the National Earthquake Hazards Reduction Program site classification, which is based on Vs30, and …

New Magnetic Field Models Of The Moon, Dhananjay Ravat, Michael E. Purucker, Nils Olsen

Earth and Environmental Sciences Research Data

We use L1-norm model regularization of |B_r| component at the surface on magnetic monopoles bases and along-track magnetic field differences alone (without vector observations) to derive high quality global magnetic field models at the surface of the Moon. The practical advantages to this strategy are: monopoles are more stable at closer spacing in comparison to dipoles, improving spatial resolution; L1-norm model regularization leads to sparse models which may be appropriate for the Moon which has regions of localized magnetic field features; and along-track differences reduce the need for ad-hoc external field noise reduction strategies. We examine also the …

Crustal Density Variation Of The Eastern U.S., Henglei Zhang, Dhananjay Ravat, Anthony R. Lowry

Earth and Environmental Sciences Research Data

EarthScope’s USArray Transportable Array (TA) has shortcomings for the purpose of interpreting geologic features of wavelengths less than the 70 km TA station spacing, but these can be overcome by using higher spatial resolution gravity data. In this study, we exploit USArray receiver functions to reduce non-uniqueness in the interpretation of gravity anomalies. We model gravity anomalies from previously-derived density variations of sedimentary basins, crustal Vp/Vs variation, Moho variation, and upper mantle density variation derived from body-wave imaging informed by surface wave tomography to estimate Vp/Vs. Although average densities and density contrasts for these seismic variations can be derived, …

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 …

Characterizations Of Linear Ground Motion Site Response In The New Madrid And Wabash Valley Seismic Zones And Seismicity In The Northern Eastern Tennessee Seismic Zone And Rome Trough, Eastern Kentucky, Nicholas Von Seth Carpenter

Theses and Dissertations--Earth and Environmental Sciences

The central and eastern United States is subject to seismic hazards from both natural and induced earthquakes, as evidenced by the 1811-1812 New Madrid earthquake sequence, consisting of at least three magnitude 7 and greater earthquakes, and by four magnitude 5 and greater induced earthquakes in Oklahoma since 2011. To mitigate seismic hazards, both earthquake sources and their effects need to be characterized.

Ground motion site response can cause additional damage to susceptible infrastructure and buildings. Recent studies indicate that Vs30, one of the primary site-response predictors used in current engineering practice, is not reliable. To investigate site response in …

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 …

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. …

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 …

Extension Of A Quaternary-Active Shear Zone Across The Reelfoot Fault Stepover Arm: Evidence From P- And Sh-Wave Seismic Reflection Imaging, Brooks Rosandich

Theses and Dissertations--Earth and Environmental Sciences

Many seismic hazard source parameters such as slip rate, total displacement, strain accommodation, geographic fault location, etc. are poorly constrained in the New Madrid seismic zone (NMSZ). This is in large part due to the masking effect of the thick Mississippi embayment sediment package on seismogenic structures and features. Consequently, much of the subsurface geologic characterization needed for understanding seismic hazard sources requires geophysical imaging. Recent seismic reflection surveys 12 km NE of the Reelfoot Fault stepover arm of the NMSZ have suggested a northeast-oriented transpressional fault zone extending across the Reelfoot Fault stepover arm where its dextral displacement at …

Integrated Seismic-Reflection And Microgravity Imaging Across The Southern Boundary Of The Charleston Uplift, New Madrid Seismic Zone, Usa, Drew D. Burford Jr.

Theses and Dissertations--Earth and Environmental Sciences

The Charleston Uplift (CU), a 30-km-long by 7-km-wide, N46°E-oriented subsurface geologic anomaly in the northern Mississippi embayment near Charleston, Missouri, exhibits up to 36 m of vertical relief across the Paleogene/Quaternary unconformity. Subsurface structural relief, along with the CU’s coincident boundary alignment with contemporary microseismicity and the New Madrid North Fault (NMNF), suggest a structural origin. Subsequent seismic soundings indicate vertical structural relief is present in Cretaceous and Paleozoic horizons, supporting the fault-controlled origin. The southern boundary (CU-s) had not been investigated, nor had any direct fault images been acquired. Integrated microgravity and seismic-reflection methods across the inferred CU-s establish …

Signature Of Obliquity And Eccentricity In Soil Chronosequences, Christopher Shepard, Jon D. Pelletier, Marcel G. Schaap, Craig Rasmussen

Plant and Soil Sciences Faculty Publications

Periodic shifts in Earth's orbit alter incoming solar radiation and drive Quaternary climate cycles. However, unambiguous detection of these orbitally driven climatic changes in records of terrestrial sedimentation and pedogenesis remains poorly defined, limiting our understanding of climate change‐landscape feedbacks, impairing our interpretation of terrestrial paleoclimate proxies, and limiting linkages among pedogenesis, sedimentation, and paleoclimatic change. Using a meta‐analysis, we show that Quaternary soil ages preserved in the modern record have periodicities of 41 and 98 kyr, consistent with orbital cycles. Further, soil ages predominantly date to periods of low rates of climatic change following rapid climate shifts associated with …

Sh-Mode Seismic-Reflection Imaging Of Earthfill Dams, Edward W. Woolery

Earth and Environmental Sciences Faculty Publications

Assessing subsurface characteristics and imaging geologic features (e.g., faults, cavities, low-velocity layers, etc.) are typical problems in near-surface geophysics. These questions often have adverse geotechnical engineering implications, and can be especially acute when associated with high-hazard structures such as large earthen flood-control dams. Dam-related issues are becoming more frequent in the United States, because a large part of this major infrastructure was designed and constructed in the early- to mid-twentieth century; these dams are thus passing into the latter stages of their design life, where minute flaws that were overlooked or thought to be insignificant in design/construction are now …

Lithologic Controls On Focused Erosion And Intraplate Earthquakes In The Eastern Tennessee Seismic Zone, Sean F. Gallen, J. Ryan Thigpen

Earth and Environmental Sciences Faculty Publications

We present a new geomorphic model for the intraplate eastern Tennessee seismic zone (ETSZ). Previous studies document that the Upper Tennessee drainage basin is in a transient state of adjustment to ~150 m of base level fall that occurred in the Late Miocene. Using quantitative geomorphology, we demonstrate that base level fall resulted in the erosion of ~3,500 km³ of highly erodibility rock in an ~70 km wide by ~350‐km‐long corridor in the Paleozoic fold‐thrust belt above the ETSZ. Models of modern incision rates show a NE‐SW trending swath of elevated erosion ~30 km southeast of the center of …

Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford

Theses and Dissertations--Earth and Environmental Sciences

Landslide characterization and hazard assessments require multidisciplinary approaches that connect geologic processes with geotechnical parameters. Field monitoring of hydrologic variables such as water content and water potential, coupled with geoelectrical measurements that can establish relationships used for geotechnical and landslide hazard investigations is deficient.

This study brings together different techniques to develop a methodology that connects geoelectrical measurements and shear strength. A field-based framework was established that includes (1) analysis of long-term soil moisture fluctuations within different landslides (2) establishment of constitutive and new equations that test the use of electrical conductivity to predict soil-water relationships and shear strength (3) …

Conservation Limnogeology And Benthic Habitat Mapping In Central Lake Tanganyika (Tanzania), Joseph S. Lucas

Theses and Dissertations--Earth and Environmental Sciences

Small scale protected zones are valuable for helping the health and productivity of fisheries at Lake Tanganyika (East Africa). Spatial placement of protected areas relies on accurate maps of benthic habitats, consisting of detailed bathymetry data and information on lake-floor substrates. This information is unknown for most of Lake Tanganyika. Fish diversity is known to correlate with rocky substrates in ≤ 30 m water depth, which provide spawning grounds for littoral and pelagic species. These benthic habitats form important targets for protected areas, if they can be precisely located.

At the NMVA, echosounding defined the position of the 30-m isobath …

Lcs-1: A High-Resolution Global Model Of The Lithospheric Magnetic Field Derived From Champ And Swarm Satellite Observations, Nils Olsen, Dhananjay Ravat, Christopher C. Finlay, Livia K. Kother

Earth and Environmental Sciences Faculty Publications

We derive a new model, named LCS-1, of Earth’s lithospheric field based on four years (2006 September–2010 September) of magnetic observations taken by the CHAMP satellite at altitudes lower than 350 km, as well as almost three years (2014 April–2016 December) of measurements taken by the two lower Swarm satellites Alpha and Charlie. The model is determined entirely from magnetic ‘gradient’ data (approximated by finite differences): the north–south gradient is approximated by first differences of 15 s along-track data (for CHAMP and each of the two Swarm satellites), while the east–west gradient is approximated by the difference between observations taken …

Initial Microseismic Recordings At The Onset Of Unconventional Hydrocarbon Development In The Rome Trough, Eastern Kentucky, Andrew Holcomb

Theses and Dissertations--Earth and Environmental Sciences

The Cambrian Rogersville Shale is a part of a hydrocarbon system in the Rome Trough of eastern Kentucky and West Virginia that can only be produced unconventionally. In Kentucky, the Rogersville Shale ranges in depth from ~1,800 to ~3,700 m below the surface with the crystalline basement ~1,000 m lower than the formation’s base. Baseline Rome Trough microseismicity data were collected, focusing on wastewater injection wells and recently completed and planned unconventional hydrocarbon test wells in the Rogersville Shale, using thirteen broadband seismic stations installed between June, 2015 and June, 2016 and existing University of Kentucky and central and eastern …

Potential Field Modeling Across The Neodymium Line Defining The Paleoproterozoic-Mesoproterozoic Boundary Of The Southeastern Margin Of Laurentia, Rachel Lauren Durham

Theses and Dissertations--Earth and Environmental Sciences

A zone of high magnetization along the SE margin of Paleoproterozoic Laurentia in the United States is indicated by magnetic anomaly data. The SE edge corresponds to the geochemical Neodymium mantle derivation model age (T_DM) boundary and the entire anomaly overlies the Paleoproterozoic Mazatzal Province. Two-dimensional gravity and magnetic models across the Nd boundary are created with Moho constrained from receiver functions with gravity, sedimentary thickness and the base of the crustal magnetization. Upper crustal magnetization does not show strong variation across this boundary and much of the strong magnetization appears to lie in the middle crust. Using …

Constraining Boundaries And Extent Of The Charleston Uplift, Northeast New Madrid Seismic Zone, Using Shallow Seismic Reflection Methods, Clara Rose Rucker

Theses and Dissertations--Earth and Environmental Sciences

A recently identified 30 km by 7.2 km subsurface stratigraphic uplift, called the Charleston uplift, exhibits 36 m offset of Paleogene-Quaternary unconformity based on shallow borehole data. Two seismic soundings demonstrated relief in Paleozoic and Cretaceous reflectors across the northern boundary of the uplift, suggesting a structural origin rather than an erosional origin. This study collected and analyzed 18 additional shallow seismic soundings to confirm Paleozoic and Cretaceous offset across the boundaries of the uplift, to better constrain the surface trace of the uplift, and to examine potential extension into western Kentucky. One ground penetrating radar profile was taken in …

Integrated Geophysical Methods In Investigation Of Claiborne Aquifer Hydrostratigraphy, Jackson Purchase, Kentucky, Marie Cooper

Theses and Dissertations--Earth and Environmental Sciences

Increased groundwater withdrawals associated with agricultural irrigation in the Jackson Purchase have prompted questions related to groundwater availability and sustainability. Key factors in addressing these questions are understanding the extent and variation in thickness of the local hydrostratigraphic system, which is the upper part of the Mississippi Embayment aquifer system. Correlations of 70 gamma-ray well logs, and 49 resistivity logs were made across parts of the Jackson Purchase in Fulton and Hickman Counties in order to delineate the upper Claiborne aquifer and middle Claiborne confining unit. Commercial software (i.e. Petra 3.8.3) was used to generate cross sections, structure and isopach …

Site Characteristics, Instrumentation, And Recordings Of The Central United States Seismic Observatory, Edward W. Woolery, Zhenming Wang, N. Seth Carpenter

Report of Investigations--KGS

The Central United States Seismic Observatory is a vertical seismic array in southwestern Kentucky within the New Madrid Seismic Zone. It is intended to record the effects of local geology, including thick sediment overburden, on seismic-wave propagation, particularly strong ground motion. The three-borehole array is composed of seismic sensors placed on the surface, in the bedrock, and at various depths within the 585-m-thick sediment overburden. The array's deep borehole also provides a unique opportunity to describe the geology and geophysically measure the complete Late Cretaceous through Quaternary stratigraphy in the northern Mississippi Embayment.

Based on the surface and borehole geophysical …

Earthquake Hazard Mitigation In The New Madrid Seismic Zone: Science And Public Policy, Alice M. Orton, Zhenming Wang, Lanmin Wang, Edward W. Woolery

Report of Investigations--KGS

In the central United States, earthquake sources that are not well defined, long earthquake recurrence intervals, and uncertain ground-motion attenuation models have contributed to an overstatement of seismic hazard for the New Madrid Seismic Zone on the national seismic hazard maps published by the U.S. Geological Survey. A series of informal interviews in western Kentucky with local businesspersons, public officials, and other professionals in occupations associated with seismic-hazard mitigation discussed seismic-mitigation policies in relation to depressed local economy. Scientific and relative economic analysis was then performed using scenario earthquake models developed with the Federal Emergency management Agency's Hazus-MH software. The …

Development Of A Semi-Automated Methodology For Discriminating Between Natural And Manmade Seismic Events Using The Oiink Seismic Array, Paul Rodriguez Asihama

Theses and Dissertations--Earth and Environmental Sciences

Broadband waveforms from the Ozark, Indiana, Illinois, Kentucky temporary seismic array OIINK, a Flexible Array in the EarthScope project, were used to develop routines to identify and remove mine blast events from a database of local events and preserve the infrequent, small, natural earthquakes. The approach taken was to first create a database of all seismic events that were detected by the OIINK Seismic Array. False-detections, events detected from outside of the project area (approx. 302 thousand square km), and known (i.e. cataloged) local earthquake were also removed. The remaining in the database were local unknown events. During the Phase …