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Full-Text Articles in Physical Sciences and Mathematics
Geoelectrical Detection Of Water Table Depth At Two Locations In The Los Osos Groundwater Basin, Hallie A. Douglas
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 …
Integrated Geophysical Exploration Of A Known Geothermal Resource: Neal Hot Springs, Clinton Ryan Colwell
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
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 Mw = 7.6. Therefore, either a seismic moment …
Analyzing Tidal Fluctuations In The Big Pine Key Freshwater Lens With Time-Lapse Resistivity, Nicole M. Tucker
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
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. …