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CreatorTitleDescriptionSubjectDate
76 Zhdanov, Michael S.Fast numerical modeling of multitransmitter electromagnetic data using multigrid quasi-linear approximationMultitransmitter electromagnetic (EM) surveys are widely used in remote-sensing and geophysical exploration. The interpretation of the multitransmitter geophysical data requires numerous three-dimensional (3-D) modelings of the responses of the receivers for different geoelectrical models of comple...Multitransmitter electromagnetic data; Numerical modeling; Multigrid quasi-linear approximation; Quasilinear approximation; geophysical exploration; 3-D modeling2006-06
77 Jewell, PaulControls of tufa development in Pleistocene Lake Bonneville, UtahProminent tufa localities along the Provo level (∼14,000 14C yr B.P.) shoreline in Pleistocene Lake Bonneville have been characterized in detail. Three types of tufa are recognized: capping tufa, beachrock, and capping tufa over beachrock. Capping tufa and beachrock are end members of a continuum ...Tufa; Pleistocene; Pluvial lakes2006
78 Fernandez, Diego P.Formulation for the static permittivity of water and steam at temperatures from 238 K to 873 K at pressures up to 1200 MPa, including derivatives and Debye- Hückel coefficientsA new formulation is presented of the static relative permittivity or dielectric constant of water and steam, including supercooled and supercritical states. The range is from 238 K to 873 K, at pressures up to 1200 MPa. The formulation is based on the ITS-90 temperature scale. It correlates a selec...Static relative permittivity; Dielectric constant1997
79 Chapman, David S.; Harris, Robert N.Climate change in India inferred from geothermal observationsTemporal variations in surface ground temperature impart a signal to the subsurface thermal regime that is captured in borehole temperature-depth profiles. Seventy temperature-depth profiles in India, located between 12o and 28oN, are analyzed to infer past changes in ground temperature.Climate change; Borehole temperatures; Surface ground temperature; Surface air temperature; Geothermal observations; India2002
80 Chapman, David S.Exhumation of the central Wasatch Mountains, Utah: 2, thermokinematic model of exhumation, erosion, and thermochronometer interpretationThe Wasatch fault is a ~370 km long normal fault in Utah that marks the boundary between the stable Colorado Plateau to the east and the extending Basin and Range to the west. Understanding the thermokinematic evolution of this fault can provide insights into intracontinental extensional tectonics a...Uplift; Exhumation; Wasatch Fault; Wasatch Mountains; Utah; Helium dating; Fission track; Tectonophysics; Extensional tectonics; Geothermal observations2002
81 Chapman, David S.Thermal analysis of the southern Powder River Basin, WyomingTemperature and geologic data from over 3000 oil and gas wells within a 180 km x 30 km area that transect across the southern Powder River Basin in Wyoming, U.S.A., were used to determine the present thermal regime of the basin. Three-dimensional temperature fields within the transect, based on...Thermal analysis; Inversion; Bottom hole temperature1996-11
82 Brown, Francis HaroldPleistocene rhyolite of the mineral mountains, Utah geothermal and archeological significance1978
83 Zhdanov, Michael S.Integral electric current method in 3-D electromagnetic modeling for large conductivity contrastAbstract-We introduce a new approach to 3-D electromagnetic (EM) modeling for models with large conductivity contrast. It is based on the equations for integral current within the cells of the discretization grid, instead of the electric field or electric current themselves, which are used in the c...Electromagnetic modeling; Integral electric current method; 3-D modeling; High conductivity contrast; Integral equations2007-05
84 Jewell, PaulPaleoredox conditions and the origin of bedded barites along the Late Devonian North American continental marginThe most important controls of the redox state of natural waters are the flux of organic matter from the photic zone, the degree of physical mixing, and oxygen concentrations of any connecting water masses. In coastal upwelling zones, these factors can be described with a simple box model constraine...Bedded barites; Late Devonian; Continental margin; Redox state1994
85 Jewell, PaulThe geology and geothermal setting of the Magic Reservoir Area, Blaine and Camas Counties, IdahoThe Magic Reservoir area straddles the Blaine- Camas county line in south-central Idaho, along the northern boundary of the central Snake River Plain. The rocks exposed at Magic Reservoir include a 5.8- million-year-old rhyolite flow, the Pliocene Square Mountain Basalt, multiple cooling units ...1982
86 Zhdanov, MichaelLarge-scale 3D inversion of marine magnetotelluric data: Case study from the Gemini prospect, Gulf of MexicoThree-dimensional magnetotelluric (MT) inversion is an emerging technique for offshore hydrocarbon exploration. We have developed a new approach to the 3D inversion of MT data, based on the integral equation method. The Tikhonov regularization and physical constraint have been used to obtain a stab...2011
87 Chapman, David S.Monitoring aquifer recharge using repeated high-precision gravity measurements: a pilot study in South Weber, UtahRepeated high-precision gravity surveys were conducted over two infiltration cycles on an alluvial-fan aquifer system at the mouth of Weber Canyon in northern Utah as part of the Weber River Basin Aquifer Storage and Recovery Pilot Project (WRBASR). Gravity measurements collected before, during, an...Aquifer recharge; Gravity measurements; Infiltration ponds; Weber River Basin Aquifer Storage and Recovery Pilot Project2008
88 Zhdanov, MichaelThree-dimensional inversion of large-scale EarthScope magnetotelluric data based on the integral equation method: geoelectrical imaging of the Yellowstone conductive mantle plumeInterpretation of the EarthScope MT (magnetotelluric) data requires the development of a large-scale inversion method which can address two common problems of 3D MT inversion: computational time and memory requirements. We have developed an efficient method of 3D MT inversion based on an IE (integ...2011
89 Jarrard, Richard D.Scientific methods: an online bookThis book was originally intended as ˜How to do science™, or ˜How to be a scientist™, providing guidance for the new scientist, as well as some reminders and tips for experienced researchers. Such a book does not need to be written by the most expert or most famous scientist, but by one who...Science; Process; Method2001
90 Brown, Francis HaroldA reappraisal of the geomagnetic polarity time scale to 4 MA using data from the turkana basin, East AfricaRecalibration of the Pliocene and early Pleistocene geomagnetic time scale using the K-Ar dated fluvial sequence of the Turkana Basin in East Africa agrees with calibrations based on astronomical calculations. Ages estimated here are: Olduvai Subchron, 1.78-1.96 Ma; Reunion Subchrons, 2.11-2.15 Ma ...2012
91 Zhdanov, Michael S.Localized S-inversion of time-domain electromagnetic dataInterpretation of time-domain electromagnetic (TDEM) data over inhomogeneous geological structures is a challenging problem of geophysical exploration. The most widely used approach of interpreting TDEM data is based on the smooth 1-D layered resistivity inversion. We have developed an effective t...2002-01-01
92 Zhdanov, Michael S.Focusing geophysical inversion imagesA critical problem in inversion of geophysical data is developing a stable inverse problem solution that can simultaneously resolve complicated geological structures. The traditional way to obtain a stable solution is based on maximum smoothness criteria. This approach, however, provides smoothe...Focusing; Geophysical inversion images; Minimum gradient support functionals; MGS1999
93 Fernandez, Diego P.Lowering the detection limit for arsenic: implications for a future practical quantitation limitExposure to arsenic (As) in drinking water is associated with an increased risk ol bladder, liver, kidney, ,ind skin cancers (Smith et al, 2002; NRG DIEGO P. FERNANDEZ, 2001). To mitigate these risks? the US Environmental Protection Agency AND JANET G. HERING (USEPA) revised the maximum contaminant ...Practical quantitation limit; Chlorine2007
94 Brown, Francis HaroldMagnetostratigraphy of the Koobi Fora Formation, Lake Turkana, KenyaThe Koobi Fora Formation, a Pliocene and Pleistocene sequence of sedimentary deposits northeast of Lake Turkana, has yielded numerous fossils and stone artifacts of early hominids. Stratigraphic correlation of the hominid-bearing deposits throughout the Turkana region was established primarily by th...1986
95 Zhdanov, Michael S.New approach to interpretation of airborne magnetic and electromagnetic dataWe present a new technique for underground imaging based on the idea of space-frequency filtering and downward continuation of the observed airborne magnetic and electromagnetic data. The technique includes two major methods. The first method is related to the downward analytical continuation and ...1996-01-01
96 Chapman, David S.Regional heat-flow variations across the sedimented Juan de Fuca Ridge eastern flank: constraints on lithospheric cooling and lateral hydrothermal heat transportSeafloor heat flow has been estimated continuously along a transect on the sedimented eastern flank of the Juan de Fuca Ridge to provide constraints on the scale and rate of lateral heat and fluid transport in the upper igneous crust, and on the total flux from the young lithosphere beneath. The ...Juan de Fuca Ridge; Seafloor; Lithospheric cooling; Hydrothermal heat transport1999
97 Brown, Francis HaroldPliocene/pleistocene formations in the lower omo basin, southern EthiopiaFollowing a two month geological reconnaissance by one of us (FHB) in 1966, four seasons of fieldwork by members of the Omo Research Expedition has added greatly to our previous, scanty knowledge of the late Cenozoic history of the lower Omo basin in southern Ethiopia. Eduard Suess (in: von Hohnel ...1970
98 Chapman, David S.Exhumation of the central Wasatch Mountains, Utah: 1, Patterns and timing of exhumation deduced from low-temperature thermochronology dataThe Wasatch Mountains are often cited as an example of normal fault growth and footwall flexure. They represent a tilted footwall at the edge of the Basin and Range extensional province, a major rift basin. Thus understanding the detailed spatial and elevation changes in coupled thermochronometer da...Uplift; Exhumation; Wasatch Fault; Wasatch Mountains; Utah; Helium dating; Fission track; Tectonophysics; Extensional tectonics; Geothermal observations2002
99 Brown, Francis HaroldTiming of volcanism and evolution of the northern Kenya RiftThe northern Kenya Rift is bounded on the west by uplands of Turkana which comprise horst-like blocks that include metamorphic basement rocks, locally overlain unconformably by the Cretaceous Lubur Sandstone, in turn overlain by predominantly volcanic sequences in which relatively thin sedimentary p...2009
100 Chapman, David S.; Harris, Robert N.Snow and the ground temperature record of climate changeBorehole temperature-depth profiles contain a record of surface ground temperature (SGT) changes with time and complement surface air temperature (SAT) analysis to infer climate change over multiple centuries. Ground temperatures are generally warmer than air temperatures due to solar radiation effe...Snow cover; Snow modeling; land/atmosphere interactions; Borehole climate reconstructions; Surface air temperature; Ground surface temperature; Borehole temperatures; Geothermal observations; Heat transfer2002
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