Geophysics and Seismology Commons^™

Observation Of Shelfwater Overrunning The Southern Slope Sea, Ajoy Kumar

OES Theses and Dissertations

Analyses of two years (1992 and 1993) of high resolution (1.47 km²) sea surface temperature satellite images of the southern Mid-Atlantic Bight (MAB), showed that unusually extensive overhang of shelf water occurs episodically, and coherently over along shelf distances of several hundred kilometers. These episodes are dubbed overrunning of the Slope Sea by shelf water. The overrunning volume has a "face" and a "back" (southern and northern limit). It transports substantial quantities of shelf water southward, and does not retreat onto the shelf, but eventually joins the western edge of the Gulf Stream in the vicinity of Chesapeake …

The Anomalous Behavior Of Sh‐Waves Across The Water Table, P. Michaels, W. Barrash

CGISS Publications and Presentations

Most theoretical studies of seismic wave propagation in a porous medium do not predict a significant increase in SH-wave velocity with increasing water saturation. Although that type of behavior is commonly predicted for P-waves (and confirmed by countless observations), the expectation for SH-waves is a slight decrease in propagation velocity with increasing water saturations. While published measurements of SH-wave velocity in laboratory studies have been supportive of such a slight decrease in velocity, the data have been biased towards high pressures (typical of oil reservoirs at large depths of burial). On the other hand, the few published low pressure laboratory …

An Assessment Of Airborne Electromagnetics For Hydrogeological Interpretation In The Wheatbelt, Western Australia, Peter De Broekert

Resource management technical reports

No abstract provided.

The Petrology Of The Precambrian Roof Pendants Thompson Peak, Sawtooth Mountains, Idaho, Susan Denise Anderson

Honors Capstones

No abstract provided.

"A Geological Interpretation Of The Stanley Fault And Other Thrust Faults In Page County, Virginia", Michael James Sarros

OES Theses and Dissertations

Paleozoic carbonate rocks flooring Page Valley (within Page County) are overthrust by Precambrian to Cambrian elastic rocks of the Blue Ridge to the east of the study area. King (1950) recognized that the Cambrian carbonate sequence of Page Valley, near Stanley, Virginia, is broken by a large transverse fault which he named the Stanley fault. King (1950) interpreted the Stanley fault as a high-angle reverse fault with oblique-slip displacement. However, detailed mapping and structural data collected in this study indicate the Stanley fault is a low angle thrust fault which cuts all pre-Alleghanian and Early Alleghanian structures.

Two previously unrecognized …

Seismic Stratigraphic Analysis Of The Upper Indus-Fan Complex A Model For Fan Development, Syed Firasat Shah

OES Theses and Dissertations

The seismic stratigraphic analysis of the upper Indus-Fan Complex has revealed the presence of six depositional sequences. Deposition of these sequences occurred primarily during the Miocene period. The Indus River drainage system that developed as a consequence of Himalayan orogeny transported the bulk of the sediments deposited in the Indus Fan. The distribution and thickness of the sequences of the upper Indus Fan are closely related to the canyon-channel systems. Seismic facies analysis of the slope has revealed the presence of a facies relationship that shows continued deepening from the time of deposition of slope fan to the latest deposits …

Reflected Light Microscopy, Electron Microscopy, Electron Spectroscopy, And X-Ray Diffraction Mineralogical Characterization Of Electric Arc Furnace (Eaf) Dusts, Ann M. Hagni

Doctoral Dissertations

"The secondary steel industry in the United States generates 600,000 tons of electric arc furnace (EAF) dust each year. Over 5,000,000 tons of EAF dust are generated annually world wide. The dust, which is removed from off-gasses from the high temperature furnaces, is considered by the Environmental Protection Agency to be hazardous waste due to its leachable lead, cadmium, and chromium. In addition to hazardous components, EAF dust contains valuable zinc, averaging 19%. This study was initiated to determine the mineralogy and characterization of the dust to aid in the processing of the dust for metals recovery and rendering the …

Role Of Acetic Acid In Siliciclastic Diagenesis: An Experimental Study, Gina Marian Bagnetto Waters

Honors Capstones

No abstract provided.

Role Of Acetic Acid In Siliciclastic Diagenesis: An Experimental Study, Gina Bagnetto Waters

Honors Capstones

No abstract provided.

Vertical Variation In Groundwater Chemistry Inferred From Fluid Specific-Conductance Well Logging Of The Snake River Plain Basalt Aquifer, Idaho National Engineering Laboratory, Southeastern Idaho, Spencer H. Wood, William Bennecke

Geosciences Faculty Publications and Presentations

Well logging of electrical fluid specific conductance (C_s) shows that permeable zones yielding ground water to intrawell flows and the water columns in some wells at INEL have highly different chemistry, with as much as a two-fold variation in C_s). This suggests that dedicated pump sampling of ground water in the aquifer may not be representative of the chemistry of the waste plumes migrating southwest of the nuclear facilities. Natural background C_s in basalt-aquifer ground water of this part of the Snake River Plain aquifer is less than 325µS/cm (microSiemans/cm), and total dissolved solids in …

Invariant Manifolds Of A Toy Climate Model, Michael Toner

Mathematics & Statistics Theses & Dissertations

According to astronomical theory, ice ages are caused by variations in the Earth's orbit. However, ice core data shows strong fluctuations in ice volume at a low frequency not significantly present in orbital variations. To understand how this might occur, the dynamics of a two dimensional nonlinear differential equation representing glacier/temperature interaction of an idealized climate was studied. Self sustained oscillation of the autonomous equation was used to model the internal mechanisms that could produce these fluctuations. Periodic parametric modulation of a damped internal oscillation was used to model periodic climate response at double the external modulation period. Both phenomena …

Periodic And Homoclinic Orbits In A Toy Climate Model, M. Toner, A. D. Kirwan Jr.

Mathematics & Statistics Faculty Publications

A two dimensional system of autonomous nonlinear ordinary differential equations models glacier growth and temperature changes on an idealized planet. We apply standard perturbative techniques from dynamical systems theory to study small amplitude periodic orbits about a constant equilibrium. The equations are put in cononical form and the local phase space topology is examined. Maximum and minimum periods of oscillation are obtained and related to the radius of the orbit. An adjacent equilibrium is shown to have saddle character and the inflowing and outflowing manifolds of this saddle are studied using numerical integration. The inflowing manifolds show the region of …

The Hydrology Of Shallow And Deep Aquifers In Relation To Secondary Soil Salinisation In Southwestern Australia, Richard J. George, Arthur J. Conacher

Natural Resources Research Articles

Results are reported from detailed research which has been carried out since 1984 on several Western Australian wheatbelt catchments, ranging in size from 12 ha to 1000 km2, in order to quantify the nature and roles of groundwater aquifers in relation to secondary salinisation. Secondary soil salinisation in the semi-arid wheatbelt has increased by 600% over the past 34 years to 440 000 ha, and is likely to increase by at least another 500% in the next 30-50 years. Changes in groundwater hydrology following the replacement of the native, woodland vegetation with agricultural crops and pastures during this century, have …

The Effects Of Composting Of Yard Wastes On The Ground-Water Quality: Wmu Farms Site, Kalamazoo, Michigan, Bryan Kirk Allen

Masters Theses

In the rush to find alternatives to landfilling of yard waste, federal and state agencies have identified composting as the main solution. There is therefore a need to address the possible environmental problems which could be associated with such composting operations. Compost may contain nutrients, organic acids, pesticides, and metals which could leach through soils to the ground water posing a potential contamination problem.

At the WMU Farms Site, two sites have been used for the composting of leaves by the City of Kalamazoo. The physical and chemical hydrogeology of these sites were characterized.

The results suggest that the presence …

The Origin And Evolution Of The Southern Snake Range Decollement, East Central Nevada, Allen J. Mcgrew

Department of Earth, Environment and Sustainability Faculty Publications

Regional and local stratigraphic, metamorphic, and structural constraints permit reconstruction of the southern Snake Range extensional deformational system in east central Nevada. The dominant structure of the range, the southern Snake Range décollement (SSRD), operated during Oligocene and Miocene extensional deformation to exhume a footwall of multiply deformed metasedimentary and plutonic rocks. Intrusion of three plutons (∼160 Ma, 79.1 ± 0.5 Ma, and 36 ± 1 Ma, respectively) and development of two cleavages preceded the onset of extensional deformation. Plastic deformation of lower plate metasedimentary rocks accompanied the early phases of regional extension and produced bedding-parallel grain shape foliations and …

Dolomite Cement Stratigraphy Of The Reelfoot Rift And The Relationship Of These Cements To Dolomite Cements Found In Southeast Missouri, Timothy James Keller

Opportunities for Undergraduate Research Experience Program (OURE)

The formation of the southeast Missouri Mississippi Valley-type Pb, Zn, Cu ore districts have been a subject of controversy. Using petrology and geochemistry, earlier studies have attempted to reveal fluid flow, composition, and origin of the ore forming fluids. In this study, the potential role of the Reelfoot rift (New Madrid seismic zone) as a source and/or conduit for ore forming fluids is addressed. By observing cuttings and cores from four oil test wells within the Reelfoot rift using cathodluminescence, four cement types were described: 1) A multiple generation cement type similar to that observed associated with mineralization in southeastern …

Depositional Facies Analysis And Sea Level Curve Determination From The Soth Western St. Francois Mts. To The Western Margin Of The Reelfoot Rift, Missouri, Aaron Ramon Rezendez

Opportunities for Undergraduate Research Experience Program (OURE)

Knowledge of the relative influence of eustatic and tectonic controls on sedimentation in basins is important to developing a regional facies model. The Reelfoot Rift basin is located on the southern margin of the North American Craton. The tectonic and sedimentary history of the rift began during Middle Cambrian time and extended through the Early Ordovician. Oil test well cuttings and cores were used to construct a stratigraphic fence extending from the Cambro- Ordovician platform west of the St. Francois Mts. southeastward info the rifted basin. Three major transgressive-regressive sequences and numerous minor transgressive-regressive sequences were observed in Cambro-Ordovician rocks …

A Versatile Shotgun Source For Engineering And Groundwater Seismic Surveys, John R. Pelton

CGISS Publications and Presentations

We describe an electrical seismic gun that is capable of firing 8-gauge blank black powder shells in a water-filled borehole under relatively high hydrostatic pressures. The new seismic gun is a modified version of the electrical shotgun source for engineering seismic surveys introduced by Pullan and MacAulay (1987). Our modifications seal the firing circuit and 8-gauge shell against water entry so underwater detonation will occur reliably at depths to at least 80 m (0.9 MPa atmospheric pressure). Source energy is controlled by varying the size of the black powder load in the shell from 50 grains to 500 grains (10 …

Basement Structure Of The Northern Ontong Java Plateau, Rick A. Hagen, Larry A. Mayer, David Mosher, Loren W. Kroenke, Tom H. Shipley, Edward L. Winterer

Affiliate Scholarship

Site surveys conducted in conjunction with Leg 130 on the Ontong Java Plateau reveal a strong seismic reflector at 0.8 to 1.0 s below the seafloor that drilling at Sites 803 and 807 confirmed is Cretaceous basalt. This reflector is generally smooth, except for the northeastern margin of the plateau, where it forms a series of small, irregularly shaped depressions. Correlatable reflectors present at the bottom of the depressions are also present on the adjacent highs, suggesting that these depressions are original volcanic topography. A strong sub-basalt reflector occurs on many seismic profiles on the northeastern portion of the plateau. …

Considerations Of Variations In Ionospheric Field Effects In Mapping Equatorial Lithospheric Magsat Magnetic Anomalies, Dhananjay Ravat, W. J. Hinze

Earth and Environmental Sciences Faculty Publications

Longitudinal, seasonal, and altitude‐dependent variability of magnetic fields is investigated in equatorial latitudes to determine their effect on the isolation of lithospheric Magsat magnetic anomalies. An estimate of ‘ionospheric effect’ was compiled by averaging the total intensity Magsat anomalies as a function of dip latitudes (called ‘dip‐latitude averages’) from dawn and dusk data sets grouped according to longitudes, time (months), and altitudes. Unanticipated seasonal variations were observed in dusk Magsat data over the Indian sector that may contribute to an improved understanding of the equatorial electrojet. The amplitudes of the dawn dip‐latitude averages are small in comparison to the dusk …

Groundwater Studies Near The Dowagiac Landfill Area, Dowagiac, Michigan, Using Seismic Resistivity Methods, Saiful B. Baharom

Masters Theses

Groundwater contamination has occurred in the vicinity of the Dowagiac landfill, Dowagiac, Michigan. The groundwater has been degraded by the presence of organic hydrocarbons, trichloroethylene in particular. At least two aquifers are thought to be present in the area with the upper unconfined aquifer being contaminated while a lower confined aquifer remains uncontaminated. This lower aquifer is thought to be protected from above by a clay layer. A combined geophysical survey consisting of seismic refraction and electrical resistivity surveys was conducted to determine the continuity and thickness of this clay layer as well as the extent of the contamination. A …

Idaho Earthquakes Of 1905, 1913, And 1916: Intensity, Location, And Magnitude Inferred From Newspaper Accounts, Lynda Koll Harpham

Boise State University Theses and Dissertations

The purpose of this project is to better understand the epicentral location, magnitude, and effects of three southern Idaho earthquakes which occurred in 1905, 1913, and 1916. The three earthquakes are of considerable interest to seismologists owing to their reported proximity to large power dams, multistory buildings, and the nuclear facilities at Idaho National Engineering Laboratory (INEL) in south-central Idaho. structures were built in previous years without assessment of the potential for earthquake damage. Therefore, an understanding of these three earthquakes is important for future development, and for the reevaluation of potential earthquake hazard and adequacy of building codes.

The …

An Electrically Detonated Downhole Seismic Gun, James C. Parker, John R. Pelton, Martin E. Dougherty

CGISS Publications and Presentations

An electrically detonated downhole seismic gun (EDG) that will fire blank 8-guage shells underwater has been constructed and tested to 80m depth (hydrostatic pressures of 130 psi or 8.9 x 10⁵ Pa). Although other engineering seismic guns which fire blank or projectile sources are available, they are for near-surface shots and are not meant to be used for downhold seismic surveys in water-filled boreholes. The EDG was designed primarily for checkshot surveys (well travel-time surveys) and high-quality reflection/refraction tests, but potential applications include shallow vertical seismic profiling and borehole to borehole or borehole to surface tomography, as well as …

Manual Of Field Techniques In Hydrology, Department Of Agriculture, Western Australia. Division Of Resource Management

Agriculture reports

No abstract provided.

A Geophysical And Geological Study Of The Farmville Triassic Basin, Charles G. James Jr.

OES Theses and Dissertations

The Farmville basin is one of many Triassic basins which are found along the eastern coast of North America, and is the largest of the central string of basins in Virginia. Meta-volcanic and metasedimentary rocks of the Chopawamsic Formation, as well as felsic intrusives are the primary lithologies surrounding the basin. A detailed gravity survey was conducted along six roads that trend approximately NW-SE, across the basin. Geologic, gravity, magnetic, and radiometric data were used to develop a kinematic model. Gravity anomalies were isolated using two-dimensional harmonic analysis methods to isolate the local, and regional anomalies. This analysis indicates that …

Statistical Prediction Of Satellite Magnetic Anomalies, H. K. Goyal, R. R. B. Von Frese, W. J. Hinze, D. N. Ravat

Earth and Environmental Sciences Faculty Publications

The geological utility of satellite magnetic observations is limited by orbital altitude variations which may be as large as a few hundred kilometres. This study investigates the use of fast and elegant statistical procedures for altitude normalization and gridding of magnetic anomaly data as an alternative to more commonly used equivalent source inversion procedures involving computationally extensive and complex least‐squares matrix methods. A standard statistical approach for gridding satellite magnetic anomalies is to recompute numerically averaged values from three‐dimensionally distributed observations which are within two standard deviations of an initially determined averaged anomaly estimate. the errors of this procedure for …

Characterization Of Radioactivity In Hot Springs National Park, Arkansas, C. E. Epperson, N. R. Rhodes

Journal of the Arkansas Academy of Science

No abstract provided.

A Geophysical Study Of The Easternmost Piedmont: Brunswick County, Virginia, Mark A. Corbin

OES Theses and Dissertations

Gravity and magnetic models indicate that a steeply dipping, mylonitic shear zone recognized by reconnaissance mapping in the easternmost Piedmont of Brunswick County, Virginia is a listric fault. A pronounced 3 to 5 mgal Bouguer anomaly high is associated with the fault zone. A band of N10° trending aeromagnetic anomalies delineate the areal extent of the fault zone. The fault zone flattens eastward over a short distance to a depth of 15 kms where it joins a near horizontal surface that cuts across the region. This surface is herein interpreted to be a decollement. The fault zone of this study …

Chirp Subbottom Profiler For Quantitative Sediment Analysis, Steven G. Schock, Lester R. Leblanc, Larry A. Mayer

Affiliate Scholarship

A wide‐band, frequency‐modulated, subbottom profiling system (the chirp sonar) can remotely determine the acoustic attenuation of ocean sediments and produce artifact‐free sediment profiles in real time. The chirp sonar is controlled by a minicomputer which performs analog‐to‐digital and digital‐to‐analog conversion, correlation processing, and attenuation estimation in real time. The minicomputer generates an FM pulse that is phase‐ and amplitude‐compensated to correct for the sonar system response. Such precise waveform control helps suppress correlation noise and source ringing. The chirp sonar, which has an effective bandwidth of 5 kHz, can generate chirp (Klauder) wavelets with a tuning thickness (Rayleigh’s criterion for …

Resistivity And Seismic Refraction Surveys Applied To A Groundwater Investigation In Richland Township, Kalamazoo County, Michigan, Homa Moaddel

Masters Theses

Many geophysical methods are increasingly being applied in investigations of contaminated sites. Among the most popular ones are resistivity and seismic refraction techniques.

In this study seismic refraction utilizing a twelve channel digital seismograph and hammer impact source provided records that have given important information about the subsurface layers. Along the same traverses, the Schlumberger resistivity method was applied at selected points. An AC digital resistivity system with a separate uncoupled transmitter (50 watts) and receiver was applied to obtain these measurements.

Geoelectrical cross-sections provided information about the variation in thickness of important layers within the glacial drift aquifer system. …