Physical Sciences and Mathematics Commons^™

Geoelectrical Detection Of Water Table Depth At Two Locations In The Los Osos Groundwater Basin, Hallie A. Douglas

Natural Resources Management and Environmental Sciences

The city of Los Osos sits on top of a coastal groundwater aquifer which is the sole supplier of all its residential, agricultural, and industrial water needs. Lacking a sewer system, the upper aquifer became progressively contaminated with nitrates over several decades. Groundwater pumping eventually shifted to the lower aquifer, however seawater intrusion of the lower aquifer caused by over-pumping has further degraded water quality. The Los Osos groundwater basin provides an excellent field region to examine the utility of geophysical methods for characterizing aquifer structure. In this study shallow (<20 >m) electrical resistivity imaging methods were performed at two …

New Approaches On The Investigation Of Covered Geothermal Fields: Exploration Of Kütahya – Şaphane – Karacaderbent Buried Geothermal Fields And Their Developments, Musa Burçak, Hüseyin Dünya, Ömer Hacisali̇hoğlu

Bulletin of the Mineral Research and Exploration

The basement in Şaphane region is constituted by Paleozoic gneiss, schist and marbles belonging to northern margin of the Menderes Massif. These basement rocks are overlain by Cretaceous aged Dağardı ophiolitic melange. All these rocks are discordantly covered by Neogene – Quaternary sedimentary and volcanic rocks deposited under lacustrine – continental environments. The main purpose of this study is to explore buried geothermal system on a covered area using geological, geophysical and geochemical methods and to develop this system by drilling investigations. Geological, geophysical, geochemical and drilling investigations, well development and test studies were applied in this research. This study …

Integrated Geophysical Exploration Of A Known Geothermal Resource: Neal Hot Springs, Clinton Ryan Colwell

Boise State University Theses and Dissertations

I present an integrated geophysical characterization of the Neal Hot Springs geothermal system in eastern Oregon. This newly established 23 MW geothermal production site is located in a region of complex geology and intersecting faults associated with two major extensional systems; the Oregon-Idaho Graben and the western Snake River Plain. The intersection of two dominant fault orientations, coupled with a high geothermal gradient from relatively thin continental crust and radioactive decay from a shallow granitic body, produces the pathways and heat needed for deep water circulation at Neal Hot Springs. New geologic mapping, geochemistry, and measurements from several boreholes in …

Seismic Slip Deficit In The Kashmir Himalaya From Gps Observations, Celia Schiffman, Bikram Singh Bali, Walter Szeliga, Roger Bilham

Faculty Scholarship for the Cascadia Hazards Institute

GPS measurements in Kashmir Himalaya reveal rangenormal convergence of 11±1 mm/yr with dextral shear of 5±1 mm/yr. The transition from a fully locked 170 km wide décollement to the unrestrained descending Indian plate occurs at ~25 km depth over an ~23 km wide transition zone. The convergence rate is consistent with the lower bounds of geological estimates for the Main Frontal Thrust, Riasi, and Balapora fault systems, on which no surface slip has been reported in the past millennium. Of the 14 damaging Kashmir earthquakes since 1123, none may have exceeded M_w = 7.6. Therefore, either a seismic moment …

Discontinuities And Alfvenic Fluctuations In The Solar Wind, G. Paschmann, S. Haaland, B. Sonnerup, T. Knetter

Dartmouth Scholarship

We examine the Alfvenicity of a set of 188 solar wind directional discontinuities (DDs) identified in the Cluster data from 2003 by Knetter (2005), with the objective of separating rotational discontinuities (RDs) from tangential ones (TDs). The DDs occurred over the full range of solar wind velocities and magnetic shear angles. By performing the Walen test in the de Hoffmann–Teller (HT) frame, we show that 77 of the 127 crossings for which a good HT frame was found had plasma flow speeds exceeding 80 % of the Alfven speed at an average angular deviation of 7.7◦; 33 cases had speeds …

Analyzing Tidal Fluctuations In The Big Pine Key Freshwater Lens With Time-Lapse Resistivity, Nicole M. Tucker

FIU Electronic Theses and Dissertations

The tidal influence on the Big Pine Key saltwater/freshwater interface was analyzed using time-lapse electrical resistivity imaging and shallow well measurements. The transition zone at the saltwater/freshwater interface was measured over part of a tidal cycle along three profiles. The resistivity was converted to salinity by deriving a formation factor for the Miami Oolite. A SEAWAT model was created to attempt to recreate the field measurements and test previously established hydrogeologic parameters. The results imply that the tide only affects the groundwater within 20 to 30 m of the coast. The effect is small and caused by flooding from the …

Evolution Of Dike Opening During The March 2011 Kamoamoa Fissure Eruption, Kīlauea Volcano, Hawai'i, Paul Lundgren, Michael Poland, Asta Miklius, Tim Orr, Sang-Ho Yun, Eric Fielding, Zhen Liu, Scott Hensley, Susan Owen, Akiko Tanaka, Walter Szeliga

Faculty Scholarship for the Cascadia Hazards Institute

The 5–9 March 2011 Kamoamoa fissure eruption along the east rift zone of Kīlauea Volcano, Hawai`i, followed months of pronounced inflation at Kīlauea summit. We examine dike opening during and after the eruption using a comprehensive interferometric synthetic aperture radar (InSAR) data set in combination with continuous GPS data. We solve for distributed dike displacements using a whole Kīlauea model with dilating rift zones and possibly a deep décollement. Modeled surface dike opening increased from nearly 1.5 m to over 2.8 m from the first day to the end of the eruption, in agreement with field observations of surface fracturing. …

Towards Model Fusion In Geophysics: How To Estimate Accuracy Of Different Models, Omar Ochoa, Aaron A. Velasco, Christian Servin

Departmental Technical Reports (CS)

In geophysics, we usually have several Earth models based on different types of data: seismic, gravity, etc. Each of these models captures some aspects of the Earth structure. To get the more description of the Earth, it is desirable to "fuse" these models into a single one. To appropriately fuse the models, we need to know the accuracy of different models. In this paper, we show that the traditional methods cannot be directly used to estimate these accuracies, and we propose a new method for such estimation.

Software Development For A 3d Gravity Inversion And Application To Study Of The Border Ranges Fault System, South-Central Alaska, Rolando Cardenas

Open Access Theses & Dissertations

The Border Ranges Fault System (BRFS) bounds the Cook Inlet and Susitna Basins, and is an important petroleum province within south-central Alaska. A primary goal of our research is to test several plausible models of structure along the BRFS using a novel three-dimensional inversion technique utilizing gravity data, constrained with other geophysical, borehole and surface geological information. This research involves the development of 3D inversion modeling software using C++ Builder from Embarcadero's XE2 Suite. The novel inversion approach directly models known geology with a priori uncertainties assigned to the geologic model to allow researchers to compare alternative interpretations. This technique …

A Geophysical Investigation To Locate Missing Graves Utilizing Ground Penetrating Radar, Electromagnetic, And Magnetic Methods, Jared Wyatt Shank

Browse all Theses and Dissertations

Old cemeteries often have graves that are unmarked because gravestones are missing or degraded and the graves are in areas for which maps or other historical documents are incomplete. This is the case for one cemetery in southwestern Ohio, known as Stevenson Cemetery, which contains graves of Revolutionary War and War of 1812 veterans. The immediate goal of this study is to locate unmarked graves in this cemetery using geophysical techniques. The broader goal is to evaluate three geophysical techniques to determine the effectiveness of each.

The three geophysical techniques evaluated in this study are magnetics, electro-magnetics, and ground-penetrating radar. …