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Sample records for included geophysical geochemical

  1. Predictive geophysics: geochemical simulations to geophysical targets

    Science.gov (United States)

    Chopping, R. G.; Cleverley, J.

    2017-12-01

    With an increasing focus on deep exploration for covered targets, new methods are required to target mineral systems under cover. Geophysical responses are driven by physical property contrasts; for example, density contrasts provide a gravity signal, acoustic impedance contrasts provide a seismic reflection signal. In turn, the physical properties for basement, crystalline rocks which host the vast majority of mineral systems are determined almost wholly by the mineralogy of the rocks in question. Mineral systems, through the transport of heat and reactive fluids, will serve to modify the physical properties of country rock as they chemically alter the hosting strata. To understand these changes, we have performed 2D reactive transport modelling that simulates the formation of Archean gold deposits of the Yilgarn Craton, Western Australia. From this, we derive a model of mineralogy that we can use to predict the density, magnetic susceptibility and seismic reflection changes associated with ore formation. It is then possible to predict the gravity, magnetic and seismic reflection responses associated with these deposits. Scenario mapping, such as testing the ability to resolve buried ore bodies or the geophysical survey spacing required to resolve the mineral system, can be performed to produce geophysical targets from these geochemical simulations. We find that there is a gravity response of around 9% of the unaltered response for deposits even buried by 1km of cover, and there is a magnetic spike associated with proximal alteration of the ore system. Finally, seismic reflection response is mostly characterised by additional reflections along faults that plumb the alteration system.

  2. The Earth's heterogeneous mantle a geophysical, geodynamical, and geochemical perspective

    CERN Document Server

    Khan, Amir

    2015-01-01

    This book highlights and discusses recent developments that have contributed to an improved understanding of observed mantle heterogeneities and their relation to the thermo-chemical state of Earth's mantle, which ultimately holds the key to unlocking the secrets of the evolution of our planet. This series of topical reviews and original contributions address 4 themes. Theme 1 covers topics in geophysics, including global and regional seismic tomography, electrical conductivity and seismic imaging of mantle discontinuities and heterogeneities in the upper mantle, transition zone and lower mantle. Theme 2 addresses geochemical views of the mantle including lithospheric evolution from analysis of mantle xenoliths, composition of the deep Earth and the effect of water on subduction-zone processes. Theme 3 discusses geodynamical perspectives on the global thermo-chemical structure of the deep mantle. Theme 4 covers application of mineral physics data and phase equilibrium computations to infer the regional-scale ...

  3. Geophysical and geochemical signatures of Gulf of Mexico seafloor brines

    Directory of Open Access Journals (Sweden)

    S. B. Joye

    2005-01-01

    Full Text Available Geophysical, temperature, and discrete depth-stratified geochemical data illustrate differences between an actively venting mud volcano and a relatively quiescent brine pool in the Gulf of Mexico along the continental slope. Geophysical data, including laser-line scan mosaics and sub-bottom profiles, document the dynamic nature of both environments. Temperature profiles, obtained by lowering a CTD into the brine fluid, show that the venting brine was at least 10°C warmer than the bottom water. At the brine pool, thermal stratification was observed and only small differences in stratification were documented between three sampling times (1991, 1997 and 1998. In contrast, at the mud volcano, substantial temperature variability was observed, with the core brine temperature being slightly higher than bottom water (by 2°C in 1997 but substantially higher than bottom water (by 19°C in 1998. Detailed geochemical samples were obtained in 2002 using a device called the 'brine trapper' and concentrations of dissolved gases, major ions and nutrients were determined. Both brines contained about four times as much salt as seawater and steep concentration gradients of dissolved ions and nutrients versus brine depth were apparent. Differences in the concentrations of calcium, magnesium and potassium between the two brine fluids suggest that the fluids are derived from different sources, have different dilution/mixing histories, or that brine-sediment reactions are more important at the mud volcano. Substantial concentrations of methane, ammonium, and silicate were observed in both brines, suggesting that fluids expelled from deep ocean brines are important sources of these constituents to the surrounding environment.

  4. Development of geophysical and geochemical data processing software based on component GIS

    International Nuclear Information System (INIS)

    Ke Dan; Yu Xiang; Wu Qubo; Han Shaoyang; Li Xi

    2013-01-01

    Based on component GIS and mixed programming techniques, a software which combines the basic GIS functions, conventional and unconventional data process methods for the regional geophysical and geochemical data together, is designed and developed. The software has many advantages, such as friendly interface, easy to use and utility functions and provides a useful platform for regional geophysical and geochemical data processing. (authors)

  5. The Nasca and Palpa geoglyphs: geophysical and geochemical data

    Science.gov (United States)

    Hartsch, Kerstin; Weller, Andreas; Rosas, Silvia; Reppchen, Gunter

    2009-10-01

    The Nasca geoglyphs in the stone desert in southern Peru are part of our world cultural heritage. These remarkable drawings have roused the interest of scientists from different disciplines. Here we report the results of integrated geophysical, petrophysical, mineralogical, and geochemical investigations of the geoglyphs at six test sites in the stone desert around Nasca and Palpa. The geomagnetic measurements revealed clear indications of subsurface structures that differ from the visible surface geoglyphs. The high-resolution geoelectrical images show unexpected resistivity anomalies underneath the geoglyphs down to a depth of about 2 m. Remarkable structures were revealed in both vertical and lateral directions. No evidence was found of geochemical or mineralogical alterations of the natural geogenic materials (desert pavement environment versus geoglyphs). Neither salts nor other mineral materials were used by the Nasca people to alter or prepare the surfaces of geoglyphs. This supports the hypothesis that the Nasca people simply removed stone material down to the natural hard pan horizon to create the geoglyphs.

  6. Perceiving the Crust in 3-D: A Model Integrating Geological, Geochemical, and Geophysical Data

    Science.gov (United States)

    Strati, Virginia; Wipperfurth, Scott A.; Baldoncini, Marica; McDonough, William F.; Mantovani, Fabio

    2017-12-01

    Regional characterization of the continental crust has classically been performed through either geologic mapping, geochemical sampling, or geophysical surveys. Rarely are these techniques fully integrated, due to limits of data coverage, quality, and/or incompatible data sets. We combine geologic observations, geochemical sampling, and geophysical surveys to create a coherent 3-D geologic model of a 50 × 50 km upper crustal region surrounding the SNOLAB underground physics laboratory in Canada, which includes the Southern Province, the Superior Province, the Sudbury Structure, and the Grenville Front Tectonic Zone. Nine representative aggregate units of exposed lithologies are geologically characterized, geophysically constrained, and probed with 109 rock samples supported by compiled geochemical databases. A detailed study of the lognormal distributions of U and Th abundances and of their correlation permits a bivariate analysis for a robust treatment of the uncertainties. A downloadable 3-D numerical model of U and Th distribution defines an average heat production of 1.5-0.7+1.4 µW/m3, and predicts a contribution of 7.7-3.0+7.7 TNU (a Terrestrial Neutrino Unit is one geoneutrino event per 1032 target protons per year) out of a crustal geoneutrino signal of 31.1-4.5+8.0 TNU. The relatively high local crust geoneutrino signal together with its large variability strongly restrict the SNO+ capability of experimentally discriminating among BSE compositional models of the mantle. Future work to constrain the crustal heat production and the geoneutrino signal at SNO+ will be inefficient without more detailed geophysical characterization of the 3-D structure of the heterogeneous Huronian Supergroup, which contributes the largest uncertainty to the calculation.

  7. Geochemical and Geophysical Signatures of Poas Volcano, Costa Rica

    Science.gov (United States)

    Martinez, M.; van Bergen, M.; Fernandez, E.; Takano, B.; Barboza, V.; Saenz, W.

    2007-05-01

    still remains open to a question if they will play a helpful role as a geophysical monitoring tool in determining the commencement of volcanic events. A range of Poas volcano geochemical and geophysical parameters have been combined to envisage relationships between them and to gain a better insight in the understanding of the Poas volcanic system.

  8. Geophysical, geochemical, mineralogical, and enivronmental data for rock samples collected in a mineralized volcanic environment, upper Animas River watershed, Colorado

    Science.gov (United States)

    McCafferty, A.E.; Horton, R.J.; Stanton, M.R.; McDougal, R.R.; Fey, D.L.

    2011-01-01

    This report provides analyses of 90 rock samples collected in the upper Animas River watershed near Silverton, Colo., from 2001 to 2007. The samples are analyzed for geophysical, geochemical, mineralogical, and environmental rock properties of acid neutralizing capacity and net acid production. The database is derived from both published (n=68) and unpublished (n=32) data. New for all samples are geophysical measurements of electrical resistivity, density, and porosity. Rock samples were acquired from 12 geologic units that include key Tertiary volcanic and plutonic lithologies, all with varying degrees of alteration.

  9. Objective computerized approaches for centralized geophysical and geochemical landscape project planning.

    Directory of Open Access Journals (Sweden)

    Danilyan Eugene Andreevich

    2013-10-01

    Full Text Available At present landscape design does not represent a scientific subject in strict sense, being a superposition of decorative and applied landscape art and the methods of graphic architectural planning. Serving interests of customers, it does not harmonize with the individual needs of the ground based on landscape geochemistry and ecology. Hence, it results in great number of grounds not consistent with each other according to geochemical criteria. In many cases total soil changing, isolation of natural hydrodynamic drainage, introduction of exotic plants interacting with their environment (including abiotic relations take place, it results in disequilibrium in the ground. Ecological system efficiency needs to be constantly artificially maintained, and that does not support its stability. In other words, without maintaining sufficient conditions, it will be influenced by succession with the course of time, as a particular case of potential gradient equalization. Hence, at present there is an acute problem to develop such a concept of landscape design, that, covering ecological requirements of customers, would be mass one, not producing gradient isolation effect and ecologically self-sustaining in given environment at the same time. It is evident, that to meet these requirements, this concept should not be the product of subjective vision of the author, but direct consequence of geophysical and geochemical landscape condition with theoretical development allowing calculation testing at any scale of geographical zoning.

  10. Merging high resolution geophysical and geochemical surveys to reduce exploration risk at glass buttes, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Patrick [Ormat Nevada, Inc., Reno, NV (United States); Fercho, Steven [Ormat Nevada, Inc., Reno, NV (United States); Perkin, Doug [Ormat Nevada, Inc., Reno, NV (United States); Martini, Brigette [Corescan Inc., Ascot (Australia); Boshmann, Darrick [Oregon State Univ., Corvallis, OR (United States)

    2015-06-01

    The engineering and studies phase of the Glass Buttes project was aimed at reducing risk during the early stages of geothermal project development. The project’s inclusion of high resolution geophysical and geochemical surveys allowed Ormat to evaluate the value of these surveys both independently and in combination to quantify the most valuable course of action for exploration in an area where structure, permeability, and temperature are the most pressing questions. The sizes of the thermal anomalies at Glass Buttes are unusually large. Over the course of Phase I Ormat acquired high resolution LIDAR data to accurately map fault manifestations at the surface and collected detailed gravity and aeromagnetic surveys to map subsurface structural features. In addition, Ormat collected airborne hyperspectral data to assist with mapping the rock petrology and mineral alteration assemblages along Glass Buttes faults and magnetotelluric (MT) survey to try to better constrain the structures at depth. Direct and indirect identification of alteration assemblages reveal not only the geochemical character and temperature of the causative hydrothermal fluids but can also constrain areas of upflow along specific fault segments. All five datasets were merged along with subsurface lithologies and temperatures to predict the most likely locations for high permeability and hot fluids. The Glass Buttes temperature anomalies include 2 areas, totaling 60 km2 (23 mi2) of measured temperature gradients over 165° C/km (10° F/100ft). The Midnight Point temperature anomaly includes the Strat-1 well with 90°C (194 °F) at 603 m (1981 ft) with a 164 °C/km (10°F/100ft) temperature gradient at bottom hole and the GB-18 well with 71°C (160 °F) at 396 m (1300 ft) with a 182°C/km (11°F/100ft) gradient. The primary area of alteration and elevated temperature occurs near major fault intersections associated with Brothers Fault Zone and Basin and Range systems. Evidence for faulting is

  11. Geophysical and geochemical characterisation of groundwater resources in Western Zambia

    DEFF Research Database (Denmark)

    Chongo, Mkhuzo; Banda, Kawawa Eddy; Bauer-Gottwein, Peter

    Zambia’s rural water supply system depends on groundwater resources to a large extent. However, groundwater resources are variable in both quantity and quality across the country and a national groundwater resources assessment and mapping program is presently not in place. In the Machile area...... in South-Western Zambia, groundwater quality problems are particularly acute. Saline groundwater occurrence is widespread and affects rural water supply, which is mainly based on shallow groundwater abstraction using hand pumps. This study has mapped groundwater quality variations in the Machile area using...... both ground-based and airborne geophysical methods as well as extensive water quality sampling. The occurrence of saline groundwater follows a clear spatial pattern and appears to be related to the palaeo Lake Makgadikgadi, whose northernmost extension reached into the Machile area. Because the lake...

  12. An integrated geophysical and geochemical exploration of critical zone weathering on opposing montane hillslope

    Science.gov (United States)

    Singha, K.; Navarre-Sitchler, A.; Bandler, A.; Pommer, R. E.; Novitsky, C. G.; Holbrook, S.; Moore, J.

    2017-12-01

    Quantifying coupled geochemical and hydrological properties and processes that operate in the critical zone is key to predicting rock weathering and subsequent transmission and storage of water in the shallow subsurface. Geophysical data have the potential to elucidate geochemical and hydrologic processes across landscapes over large spatial scales that are difficult to achieve with point measurements alone. Here, we explore the connections between weathering and fracturing, as measured from integrated geochemical and geophysical borehole data and seismic velocities on north- and south-facing aspects within one watershed in the Boulder Creek Critical Zone Observatory. We drilled eight boreholes up to 13 m deep on north- and south-facing aspects within Upper Gordon Gulch, and surface seismic refraction data were collected near these wells to explore depths of regolith and bedrock, as well as anisotropic characteristics of the subsurface material due to fracturing. Optical televiewer data were collected in these wells to infer the dominant direction of fracturing and fracture density in the near surface to corroborate with the seismic data. Geochemical samples were collected from four of these wells and a series of shallow soil pits for bulk chemistry, clay fraction, and exchangeable cation concentrations to identify depths of chemically altered saprolite. Seismic data show that depth to unweathered bedrock, as defined by p-wave seismic velocity, is slightly thicker on the north-facing slopes. Geochemical data suggest that the depth to the base of saprolite ranges from 3-5 m, consistent with a p-wave velocity value of 1200 m/s. Based on magnitude and anisotropy of p-wave velocities together with optical televiewer data, regolith on north-facing slopes is thought to be more fractured than south-facing slopes, while geochemical data indicate that position on the landscape is another important characteristic in determining depths of weathering. We explore the importance

  13. pplication of Fractal Technique for Analysis of Geophysical - Geochemical Databases in Tekieh Pb-Zn Ore Deposit (SE of Arak

    Directory of Open Access Journals (Sweden)

    Seyed Reza Mehrnia

    2017-02-01

    calculated based on measuring the fractal dimensional variations in the recursive patterns (Mehrnia, 2013. In practice, the Area-Concentration equations (Mandelbrot, 2005 were applied in resistivity, induction polarization, Pb and Zn datasets for achieving the nonlinear relationships in anomalous regions which were characterized by increasing in regression coefficients with more spatial correlation of the variable than linear statistics (Mehrnia, 2013. Results and Discussion This research showed that both linear and nonlinear statistics are able to estimate the spatial association of geochemical anomalies with geophysical variables. A meaningful increase in the regression coefficient was also revealed after measuring the self-similar peculiarities of concentration values on gridded plots (Salehi, 2004; Torkashvand et al., 2009. From the fractal point of view, Pb ore-minerals have been deposited in the western sub-region, while Zn mineralization seems to be extended in the depth of eastern alterations. Also a predictable geochemical zonation can be considered in the western target (meaningful Pb anomalies that is more patterned than the eastern halos according to geological observations (Momenzadeh and Ziseman, 1981 and mineralogical evidences (Salehi, 2004. An increase in Supra ore/Sub ore proportional content was measured in the western sub-region which indicated more reliable potential of Pb mineralization (Galena as a particular indication of sulfide-rich minerals than the same phases of ore forming processes in the eastern sub-region, although the content of Pb-ores rapidly decreases in the eastern target and is replaced by Zn minerals (Sphalerite as particular indication of sulfide-rich mineralization. Because power law relationships are significant in both geochemical and geophysical anomalies (Mehrnia, 2013 a detailed program including borehole geophysics and litho-geochemical land-surveys should be considered in the prospected regions. Therefore, upcoming phases

  14. Water information bulletin No. 30: geothermal investigations in Idaho. Part 11. Geological, hydrological, geochemical and geophysical investigations of the Nampa-Caldwell and adjacent areas, southwestern Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J.C. (ed.)

    1981-12-01

    The area under study included approximately 925 sq km (357 sq mi) of the Nampa-Caldwell portion of Canyon County, an area within the central portion of the western Snake River Plain immediately west of Boise, Idaho. Geologic mapping, hydrologic, geochemical, geophysical, including detailed gravity and aeromagnetic surveys, were run to acquire needed data. In addition, existing magnetotelluric and reflection seismic data were purchased and reinterpreted in light of newly acquired data.

  15. Development of data processing system for regional geophysical and geochemical exploration of sandstone-hosted uranium deposits based on ArcGIS Engine

    International Nuclear Information System (INIS)

    Han Shaoyang; Ke Dan; Hou Huiqun; Hu Shuiqing

    2010-01-01

    According to the data processing need of geophysical and geochemical exploration of sandstone-hosted uranium deposits, the function design of the regional geophysical and geochemical data processing system is completed in the paper. The geophysical and geochemical data processing software with powerful functions is also developed based on ArcGIS Engine which remedies the shortage of GIS software for performing the geophysical and geochemical data processing. The development technique route of system software and key techniques are introduced, and the development processes of system software are showed through some development examples. Application practices indicate that the interface of developed system software with friendly interface and utility functions, may quickly perform the data processing of regional geophysical and geochemical exploration and provide the helpful deep information for predicting metallogenic prospective areas of sandstone-hosted uranium deposits. The system software is of a great application foreground. (authors)

  16. Digital image processing applied to analysis of geophysical and geochemical data for southern Missouri

    Science.gov (United States)

    Guinness, E. A.; Arvidson, R. E.; Leff, C. E.; Edwards, M. H.; Bindschadler, D. L.

    1983-01-01

    Digital image-processing techniques have been used to analyze a variety of geophysical and geochemical map data covering southern Missouri, a region with important basement and strata-bound mineral deposits. Gravity and magnetic anomaly patterns, which have been reformatted to image displays, indicate a deep crustal structure cutting northwest-southeast through southern Missouri. In addition, geologic map data, topography, and Landsat multispectral scanner images have been used as base maps for the digital overlay of aerial gamma-ray and stream sediment chemical data for the 1 x 2-deg Rolla quadrangle. Results indicate enrichment of a variety of elements within the clay-rich alluvium covering many of the interfluvial plains, as well as a complicated pattern of enrichment for the sedimentary units close to the Precambrian rhyolites and granites of the St. Francois Mountains.

  17. Geophysical and geochemical models of the Earth's shields and rift zones

    International Nuclear Information System (INIS)

    Chung, D.H.

    1977-01-01

    This report summarizes a collection of, synthesis of, and speculation on the geophysical and geochemical models of the earth's stable shields and rift zones. Two basic crustal types, continental and oceanic, and two basic mantle types, stable and unstable, are described. It is pointed out that both the crust and upper mantle play a strongly interactive role with surface geological phenomena ranging from the occurrence of mountains, ocean trenches, oceanic and continental rifts to geographic distributions of earthquakes, faults, and volcanoes. On the composition of the mantle, there is little doubt regarding the view that olivine constitutes a major fraction of the mineralogy of the earth's upper mantle. Studies are suggested to simulate the elasticity and composition of the earth's lower crust and upper mantle

  18. Geological, geochemical, and geophysical survey of the geothermal resources at Hot Springs Bay Valley, Akutan Island, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Motyka, R.J.; Wescott, E.M.; Turner, D.L.; Swanson, S.E.; Romick, J.D.; Moorman, M.A.; Poreda, R.J.; Witte, W.; Petzinger, B.; Allely, R.D.

    1985-01-01

    An extensive survey was conducted of the geothermal resource potential of Hot Springs Bay Valley on Akutan Island. A topographic base map was constructed, geologic mapping, geophysical and geochemical surveys were conducted, and the thermal waters and fumarolic gases were analyzed for major and minor element species and stable isotope composition. (ACR)

  19. Geochemical mapping in polluted floodplains using handheld XRF, geophysical imaging, and geostatistics

    Science.gov (United States)

    Hošek, Michal; Matys Grygar, Tomáš; Popelka, Jan; Kiss, Timea; Elznicová, Jitka; Faměra, Martin

    2017-04-01

    In the recent years researchers have enjoyed noticeable improvements of portable analytical and geophysical methods, which allow studying floodplain architecture and deciphering pollutant distribution more easily than ever before. Our area of interest was floodplain of the Ploučnice River, particularly a pollution hotspot in Boreček, severely impacted by U mining between the 1970s and late 1980s, in particular a "radioactive flood" in 1981. In the area, we used hand drill coring and in situ (field) analysis of so acquired sediments by handheld X-ray fluorescence spectrometer (XRF), which gave us information about depth profiles of pollutants (Ba, U, Zn) and the Al/Si and Zr/Rb ratios, i.e., proxies for sediment lithology. We found that spatial distribution of pollutants (control by depth and position in the floodplain) is apparently complex and discontinuous. In some places, contamination is buried by a couple decimetres of less polluted sediments, while in other places the peak pollution is near surface, apparently without a straightforward connection with the surface topography and the distance to the river channel. We thus examined the floodplain architecture, the internal structure of the floodplain using two geophysical methods. First of them, dipole electromagnetic profiling (DEMP, also denoted EMP, MP, or Slingram) quickly acquires average electric resistivity in top strata in selected areas, which was actually top 3 m with our particular instrument. Second, electric resistivity tomography (ERT) produces much more detailed information on resistivity with depth resolution of ca 0.5 m to the depth of ca 5 m in selected lines. ERT thus allows identifying boundaries of electric resistivity domains (sediment bodies) and DEMP their spatial distribution. Based on the obtained data, we divided the floodplain to five segments with specific topography, pollution characteristics, and electric resistivity. We suppose that those segments are lithogenetic floodplain

  20. Geophysical Monitoring of Coupled Microbial and Geochemical Processes During Stimulated Subsurface Bioremediation

    International Nuclear Information System (INIS)

    Williams, Kenneth H.; Kemna, Andreas; Wilkins, Michael J.; Druhan, Jennifer L.; Arntzen, Evan V.; N'Guessan, A. Lucie; Long, Philip E.; Hubbard, Susan S.; Banfield, Jillian F.

    2009-01-01

    Understanding how microorganisms alter their physical and chemical environment during bioremediation is hindered by our inability to resolve subsurface microbial activity with high spatial resolution. Here we demonstrate the use of a minimally invasive geophysical technique to monitor stimulated microbial activity during acetate amendment in an aquifer near Rifle, Colorado. During electrical induced polarization (IP) measurements, spatiotemporal variations in the phase response between imposed electric current and the resultant electric field correlated with changes in groundwater geochemistry accompanying stimulated iron and sulfate reduction and sulfide mineral precipitation. The magnitude of the phase response varied with measurement frequency (0.125 and 1 Hz) and was dependent upon the dominant metabolic process. The spectral effect was corroborated using a biostimulated column experiment containing Rifle sediments and groundwater. Fluids and sediments recovered from regions exhibiting an anomalous phase response were enriched in Fe(II), dissolved sulfide, and cell-associated FeS nanoparticles. The accumulation of mineral precipitates and electroactive ions altered the ability of pore fluids to conduct electrical charge, accounting for the anomalous IP response and revealing the usefulness of multifrequency IP measurements for monitoring mineralogical and geochemical changes accompanying stimulated subsurface bioremediation

  1. Insight into eruptive cyclic behavior of Mount Etna during 2011: geophysical and geochemical constraints

    Science.gov (United States)

    Coltelli, M.; Patanè, D.; Aiuppa, A.; Aliotta, M.; Aloisi, M.; Behncke, B.; Cannata, A.; Cannavò, F.; Di Grazia, G.; Gambino, S.; Gurrieri, S.; Mattia, M.; Montalto, P.; Prestifilippo, M.; Puglisi, G.; Salerno, G.; Scandura, D.

    2012-04-01

    The period 2009-2011 at Mt. Etna was characterized by a gradual intensification of volcanic activity. In particular, after the end of the 2008-2009 eruption a resting phase took place and lasted up to the first months of 2010. In 2010 several episodes of minor explosions, taking place at the summit craters and accompanied by mild ash emissions, testified the ongoing recharging phase started at the end of 2009 suggested by ground deformation GPS data. During 2011 volcanic activity culminated with a series of 18 lava fountains, occurring at the new South-East crater. A multiparametric approach, consisting in collecting and comparing volcanological, geophysical and geochemical data, was applied to investigate the volcano dynamics during 2009-2011. In particular, temporal and/or spatial variations of volcanic tremor, long period events, very long period events, soil deformation (GPS and tiltmeter data), SO2 flux, SO2/CO2 ratio were studied. Further, on the basis of such data FEM models were developed to follow the evolution of intrusive and eruptive processes. In conclusion, new insights into the geometry of the magma plumbing system feeding the fountaining activities, as well as into the processes of magma discharge and recharge, were obtained.

  2. Geologic, geophysical, and geochemical aspects of site-specific studies of the geopressured-geothermal energy resource of southern Louisiana. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pilger, R.H. Jr. (ed.)

    1985-01-01

    The report consists of four sections dealing with progress in evaluating geologic, geochemical, and geophysical aspects of geopressured-geothermal energy resources in Louisiana. Separate abstracts have been prepared for the individual sections. (ACR)

  3. An integrated geological, geochemical, and geophysical investigation of uranium metallogenesis in selected granitic plutons of the Miramichi Anticlinorium, New Brunswick

    International Nuclear Information System (INIS)

    Hassan, H.H.; McAllister, A.L.

    1992-01-01

    Integrated geological, geochemical, and geophysical data for the post-tectonic granitic rocks of the North Pole, Burnthill, Dungarvon, Trout Brook, and Rocky Brook plutons and surrounding areas were examined to assess their potential for uranium mineralization. Geological, geochemical, and geophysical criteria that are thought to be useful guides for uranium exploration were also established for the host granites. The granitic plutons were emplaced discordantly, late in the tectonomagmatic sequence and at shallow depths within the metasedimentary rocks of the Miramichi Anticlinorium. Geochemically, the host granites are highly evolved (Si0 2 > 75 wt. %), peraluminous and have strong similarities with ilmenite-series 'S-type' and 'A-type' granitoids. Uranium occurrences are spatially and perhaps temporally associated with late-phase differentiates of the plutons where elevated levels of other lithophile elements such as Sn, W, Mo, and F were also detected. Geophysically, the granitic plutons are associated with distinctively high aeroradiometric eU, eTh, and K anomalies that coincide with strong negative Bouguer anomalies and low magnetic values. Conceptual models involving magmatic and hydrothermal processes have been adopted to explain the concentration of uranium and associated metals in the granitic plutons

  4. Descriptions of mineral occurrences and interpretation of mineralized rock geochemical data in the Stikine geophysical survey area, Southeastern Alaska

    Science.gov (United States)

    Taylor, Cliff D.

    2003-01-01

    Detailed descriptions of some of the more significant mineral occurrences in the Stikine Airborne Geophysical Survey Project Area are presented based upon site-specific examinations by the U.S. Geological Survey in May of 1998. Reconnaissance geochemical data on unmineralized igneous and sedimentary host rocks, and mineralized rocks are also presented and are accompanied by a brief analysis of geochemical signatures typical of each occurrence. Consistent with the stated goal of the geophysical survey; to stimulate exploration for polymetallic massive sulfides similar to the Greens Creek deposit, the majority of the described occurrences are possible members of a belt of Late Triassic mineral deposits that are distributed along the eastern edge of the Alexander terrane in southeastern Alaska. Many of the described occurrences in the Duncan Canal-Zarembo Island area share similarities to the Greens Creek deposit. When considered as a whole, the geology, mineralogy, and geochemistry of these occurrences help to define a transitional portion of the Late Triassic mineral belt where changes in shallow to deeper water stratigraphy and arc-like to rift-related igneous rocks are accompanied by concomitant changes in the size, morphology, and metal endowments of the mineral occurrences. As a result, Late Triassic mineral occurrences in the area appear as: 1) small, discontinuous, structurally controlled stockwork veins in mafic volcanic rocks, 2) small, irregular replacements and stratabound horizons of diagenetic semi-massive sulfides in dolostones and calcareous shales, and as 3) larger, recognizably stratiform accumulations of baritic, semi-massive to massive sulfides at and near the contact between mafic volcanic rocks and overlying sedimentary rocks. Empirical exploration guidelines for Greens Creek-like polymetallic massive sulfide deposits in southeastern Alaska include: 1) a Late Triassic volcano-sedimentary host sequence exhibiting evidence of succession from

  5. How inheritance, geochemical and geophysical properties of the lithospheric mantle influence rift development and subsequent collision

    Science.gov (United States)

    Picazo, Suzanne; Chenin, Pauline; Müntener, Othmar; Manatschal, Gianreto; Karner, Garry; Johnson, Christopher

    2017-04-01

    In magma-poor rifted margins, the rift structures, width of necking zones and overall geometry are controlled by the heterogeneities of geochemical and geophysical properties of the crust and mantle. In this presentation we focus on the mantle heterogeneities and their major implications on the closure of a hyper-extended rifted system. In our study, we review the clinopyroxene and spinel major element composition from the Liguria-Piemonte domain, the Pyrenean domain, the Dinarides and Hellenides ophiolites and the Iberia-Newfoundland rifted margins (Picazo et al, 2016). It would seem that during an extensional cycle i.e., from post-orogenic collapse to polyphase rifting to seafloor spreading, the mineral compositions of mantle peridotites are systematically modified. The initially heterogeneous subcontinental mantle cpx (inherited mantle type 1) equilibrated in the spinel peridotite field and is too enriched in Na2O and Al2O3 to be a residue of syn-rift melting. The heterogeneous inherited subcontinental mantle becomes progressively homogenized due to impregnation by MORB-type melts (refertilized mantle-type 2) during extensional thinning of the lithosphere. At this stage, cpx equilibrate with plagioclase and display lower Na2O and Al2O3 and high Cr2O3 contents. The system might evolve into breakup and oceanization (mantle type 3) i.e., self-sustained steady-state seafloor spreading. The different mantle-types are present in various reconstructed sections of magma-poor margins and display a systematic spatial distribution from mantle type 1 to 3 going oceanwards in Western and Central Europe. We estimated the density of the three identified mantle types using idealized modal peridotite compositions using the algorithm by Hacker et al, (2003). The density of the refertilized plagioclase peridotite is predicted to be lower than that of inherited subcontinental and depleted oceanic mantle. This has some interesting consequences on the reactivation of rifted margins

  6. Joint Inversion of Geochemical Data and Geophysical Logs for Lithology Identification in CCSD Main Hole

    Science.gov (United States)

    Deng, Chengxiang; Pan, Heping; Luo, Miao

    2017-12-01

    The Chinese Continental Scientific Drilling (CCSD) main hole is located in the Sulu ultrahigh-pressure metamorphic (UHPM) belt, providing significant opportunities for studying the metamorphic strata structure, kinetics process and tectonic evolution. Lithology identification is the primary and crucial stage for above geoscientific researches. To release the burden of log analyst and improve the efficiency of lithology interpretation, many algorithms have been developed to automate the process of lithology prediction. While traditional statistical techniques, such as discriminant analysis and K-nearest neighbors classifier, are incompetent in extracting nonlinear features of metamorphic rocks from complex geophysical log data; artificial intelligence algorithms are capable of solving nonlinear problems, but most of the algorithms suffer from tuning parameters to be global optimum to establish model rather than local optimum, and also encounter challenges in making the balance between training accuracy and generalization ability. Optimization methods have been applied extensively in the inversion of reservoir parameters of sedimentary formations using well logs. However, it is difficult to obtain accurate solution from the logging response equations of optimization method because of the strong overlapping of nonstationary log signals when applied in metamorphic formations. As oxide contents of each kinds of metamorphic rocks are relatively less overlapping, this study explores an approach, set in a metamorphic formation model and using the Broyden Fletcher Goldfarb Shanno (BFGS) optimization algorithm to identify lithology from oxide data. We first incorporate 11 geophysical logs and lab-collected geochemical data of 47 core samples to construct oxide profile of CCSD main hole by using backwards stepwise multiple regression method, which eliminates irrelevant input logs step by step for higher statistical significance and accuracy. Then we establish oxide response

  7. A geochemical and geophysical reappraisal to the significance of the recent unrest at Campi Flegrei caldera (Southern Italy)

    Science.gov (United States)

    Moretti, Roberto; De Natale, Giuseppe; Troise, Claudia

    2017-04-01

    Volcanic unrest at calderas involve complex interaction between magma, hydrothermal fluids and crustal stress and strain. Campi Flegrei caldera (CFc), located in the Naples (Italy) area and characterised by the highest volcanic risk on Earth for the extreme urbanisation, undergoes unrest phenomena involving several meters of uplift and intense shallow micro-seismicity since several decades. Despite unrest episodes display in the last decade only moderate ground deformation and seismicity, current interpretations of geochemical data point to a highly pressurized hydrothermal system. We show that at CFc, the usual assumption of vapour-liquid coexistence in the fumarole plumes leads to largely overestimated hydrothermal pressures and, accordingly, interpretations of elevated unrest. By relaxing unconstrained geochemical assumptions, we infer an alternative model yielding better agreement between geophysical and geochemical observations. The model reconciles discrepancies between what observed 1) for two decades since the 1982-84 large unrest, when shallow magma was supplying heat and fluids to the hydrothermal system, and 2) in the last decade. Compared to the 1980's unrest, the post-2005 phenomena are characterized by much lower aquifers overpressure and magmatic involvement, as indicated by geophysical data and despite large changes in geochemical indicators. Our interpretation points out a model in which shallow sills, intruded during 1969-1984, have completely cooled, so that fumarole emissions are affected now by deeper, CO2-richer, magmatic gases producing a relatively modest heating and overpressure of the hydrothermal system. Our results do have important implications on the short-term eruption hazard assessment and on the best strategies for monitoring and interpreting geochemical data.

  8. Geological, geochemical, and geophysical studies by the U.S. Geological Survey in Big Bend National Park, Texas

    Science.gov (United States)

    Page, W.R.; Turner, K.J.; Bohannon, R.G.; Berry, M.E.; Williams, V.S.; Miggins, D.P.; Ren, M.; Anthony, E.Y.; Morgan, L.A.; Shanks, P.W.C.; Gray, J. E.; Theodorakos, P.M.; Krabbenhoft, D. P.; Manning, A.H.; Gemery-Hill, P. A.; Hellgren, E.C.; Stricker, C.A.; Onorato, D.P.; Finn, C.A.; Anderson, E.; Gray, J. E.; Page, W.R.

    2008-01-01

    Big Bend National Park (BBNP), Tex., covers 801,163 acres (3,242 km2) and was established in 1944 through a transfer of land from the State of Texas to the United States. The park is located along a 118-mile (190-km) stretch of the Rio Grande at the United States-Mexico border. The park is in the Chihuahuan Desert, an ecosystem with high mountain ranges and basin environments containing a wide variety of native plants and animals, including more than 1,200 species of plants, more than 450 species of birds, 56 species of reptiles, and 75 species of mammals. In addition, the geology of BBNP, which varies widely from high mountains to broad open lowland basins, also enhances the beauty of the park. For example, the park contains the Chisos Mountains, which are dominantly composed of thick outcrops of Tertiary extrusive and intrusive igneous rocks that reach an altitude of 7,832 ft (2,387 m) and are considered the southernmost mountain range in the United States. Geologic features in BBNP provide opportunities to study the formation of mineral deposits and their environmental effects; the origin and formation of sedimentary and igneous rocks; Paleozoic, Mesozoic, and Cenozoic fossils; and surface and ground water resources. Mineral deposits in and around BBNP contain commodities such as mercury (Hg), uranium (U), and fluorine (F), but of these, the only significant mining has been for Hg. Because of the biological and geological diversity of BBNP, more than 350,000 tourists visit the park each year. The U.S. Geological Survey (USGS) has been investigating a number of broad and diverse geologic, geochemical, and geophysical topics in BBNP to provide fundamental information needed by the National Park Service (NPS) to address resource management goals in this park. Scientists from the USGS Mineral Resources and National Cooperative Geologic Mapping Programs have been working cooperatively with the NPS and several universities on several research studies within BBNP

  9. Application of the geophysical and geochemical methods to the research for uranium

    International Nuclear Information System (INIS)

    Gangloff, A.M.; Collin, C.R.; Grimbert, A.; Sanselme, H.

    1958-01-01

    Since 1954, at the Commissariat a l'energie atomique, geophysics and geochemistry have been added to routine geological surveying and radiometric observations. Geophysical prospecting reveals the tectonic structures linked with French uranium deposits and gives an idea of favorable zones. Geochemistry adds to the geophysical indirect methods further details on the distribution of uranium traces in the soils. This method is direct and specific. Uranium assay in waters and alluvial deposits find its use in preliminary exploration. (author) [fr

  10. Geophysical and geochemical regional evaluation and geophysical model for uranium exploration in the western part of Yanliao region

    International Nuclear Information System (INIS)

    Liu Tengyao; Cui Huanmin; Chen Guoliang; Zhai Yugui

    1992-01-01

    The western part of Yanliao region is an important uranium metallogenic region. This paper summarizes the regional geophysical model for uranium exploration composed of prediction model for favourable area of mineralization and evaluation model for anomalies on the basis of aeromagnetic and aeroradiometric data interpretation and analysis of the data from carborane and ground gamma spectrometric survey, high accurate magnetic survey, VLF survey and α-collected film survey in mult-displiary research work. The prospective prediction for uranium metallogenesis in this region was also conducted

  11. Geophysical and geochemical processing of data from the Santa Terezinha de Goias region, Brazil

    International Nuclear Information System (INIS)

    Calle, Carlos Humberto Tapia; Pires, A.C.B.

    1995-01-01

    The paper presents a few data processing techniques used with geophysical and geometry data from Santa Terezinha de Goias. Airborne gamma ray spectrometry and magnetometry were conduced in the area during the Brazil Canada Geophysical Project. Black and white and color images produced using available procedures resulted in new interpretation for the geological mapping. Guidelines for emerald exploration in the area are suggested from images and anomalous potassium map. (author). 14 refs., 5 figs

  12. Application of Fractal Technique for Analysis of Geophysical - Geochemical Databases in Tekieh Pb-Zn Ore Deposit (SE of Arak)

    International Nuclear Information System (INIS)

    Mehrnia, S.R.

    2017-01-01

    In this research, two statistical techniques that consist of classical and fractal equations (Mandelbrot, 2005) were applied in geochemical (Torkashvand et al., 2009) and geophysical (Jafari, 2007) databases for obtaining the linear and nonlinear distributions of geochemical elements (Tekieh Pb-Zn content) in association with resistivity variations and induction polarization measurements (Calagari, 2010). According to linear statistical techniques (Torkashvand et al., 2009), the main central parameters such as mean, median and mode in addition to variances and standard deviations as distribution tendencies could be used for obtaining the regression coefficients of the databases. However, in fractal statistics, a reliable regression between geo electrical - geochemical anomalies should be calculated based on measuring the fractal dimensional variations in the recursive patterns (Mehrnia, 2013). In practice, the Area-Concentration equations (Mandelbrot, 2005) were applied in resistivity, induction polarization, Pb and Zn datasets for achieving the nonlinear relationships in anomalous regions which were characterized by increasing in regression coefficients with more spatial correlation of the variable than linear statistics (Mehrnia, 2013).

  13. Geophysics

    CERN Document Server

    Bolt, Bruce

    1973-01-01

    Methods in Computational Physics, Volume 13: Geophysics is a 10-chapter text that focuses with the theoretical solid-earth geophysics. This volume specifically covers the general topics of terrestrial magnetism and electricity, the Earth's gravity field, tidal deformations, dynamics of global spin, spin processing, and convective models for the deep interior. This volume surveys first the construction of mathematical models, such as the representation of the geomagnetic field by assuming arrangements of multipole sources in the core and the fast computer evaluation of two- and three-dimensiona

  14. Geophysics

    Science.gov (United States)

    Carr, M. H.; Cassen, P.

    1976-01-01

    Four areas of investigation, each dealing with the measurement of a particular geophysical property, are discussed. These properties are the gravity field, seismicity, magnetism, and heat flow. All are strongly affected by conditions, past or present, in the planetary interior; their measurement is the primary source of information about planetary interiors.

  15. Combined geophysical, geochemical and geological investigations of geothermal reservoir characteristics in Lower Saxony, Germany

    Science.gov (United States)

    Hahne, B.; Thomas, R.

    2012-04-01

    The North German basin provides a significant geothermal potential, although temperature gradients are moderate. However, deep drilling up to several thousand meters is required to reach temperatures high enough for efficient generation of geothermal heat and electric power. In these depths we have not much information yet about relevant physical properties like porosity or permeability of the rock formations. Therefore the costs of developing a geothermal reservoir and the risk of missing the optimum drilling location are high. The collaborative research association "Geothermal Energy and High Performance Drilling" (gebo) unites several universities and research institutes in Lower Saxony, Germany. It aims at a significant increase of economic efficiency by introducing innovative technology and high tech materials resisting temperatures up to 200 °C in the drilling process. Furthermore, a better understanding of the geothermal reservoir is essential. gebo is structured into four main fields: Drilling Technology, Materials, Technical Systems and Geosystem. Here, we show the combined work of the Geosystem group, which focuses on the exploration of geological fault zones as a potential geothermal reservoir as well as on modeling the stress field, heat transport, coupled thermo-hydro-mechanical processes, geochemical interactions and prediction of the long-term behavior of the reservoir. First results include combined seismic and geoelectric images of the Leinetalgraben fault system, a comparison of seismic images from P- and S-wave measurements, mechanical properties of North German rocks from field and laboratory measurements as well as from drill cores, seismological characterization of stimulated reservoirs, a thermodynamic "gebo" database for modeling hydrogeochemical processes in North German formation waters with high salinity and at high temperatures, stress models for specific sites in northern Germany, and modeling results of permeability and heat transport

  16. Geochemical mapping in polluted floodplains using handheld XRF, geophysical imaging, and geostatistics

    Czech Academy of Sciences Publication Activity Database

    Hošek, Michal; Matys Grygar, Tomáš; Popelka, J.; Kiss, T.; Elznicová, J.; Faměra, Martin

    2017-01-01

    Roč. 19, APR (2017) ISSN 1607-7962. [EGU General Assembly 2017. 23.04.2017-28.04.2017, Vienna] Institutional support: RVO:61388980 Keywords : Dipole electromagneting profilling * electric resistivity tomography * floodplain contamination * geochemical mapping Subject RIV: DD - Geochemistry http://meetingorganizer.copernicus.org/EGU2017/EGU2017-3573-3.pdf

  17. Pre-selection tests on geophysical and geochemical exploration methods for in-situ leachable sandstone-type uranium deposit in Erlian Basin

    International Nuclear Information System (INIS)

    Zhang Shouben; Tan Chenglong; Jiang Yongyi; Wu Duanyang

    1997-01-01

    The authors introduce the application tests and their results on the Nuheting deposit using non-conventional geophysical and geochemical methods. Through effective analysis on the screened methods, a method combination for the exploration of the in-situ leachable sandstone-type uranium deposit in Erlian Basin has been presented

  18. Constraining Lateral Evolution of Magmatic Behavior in North Tanzania from Geophysical and Geochemical Analyses

    Science.gov (United States)

    Gautier, S.; Tiberi, C.; Parat, F.; Baudouin, C.

    2016-12-01

    In the framework of CRAFTI and CoLiBrEA experiments in 2013, we proceeded to both seismic and geochemical studies along an EW profile through the North Tanzania Divergence. The data were collected along a line starting at the Ngorongoro volcanic area, ending at Kitumbeine edifice and crossing the rift valley. Recent seismological studies show lateral and depth variations for both velocity and Vp/Vs ratio within this area, particularly a change of Moho depth between the western and central parts of the rift. These two zones also exhibit diverse geochemical signatures that involve different magma storage (depth of reservoir, magma volume) and ascent as well as higher partial melts content for the western part. We take advantage of the recent and precise 3D lithospheric velocity models and receiver functions in this area to compare the structure and nature of Ngorongoro area and rift valley. We first compute ray path and establish regional coherency maps between piercing points, Vp/Vs ratio and tomographic images. Second, those results are compared with the composition of magma at depth obtained from a petrophysical and geochemical analysis of lava samples. We will discuss those results in terms of magmatic processes, and how they interact with the rifting in a cratonic lithosphere.

  19. Relative roles of rifting tectonics and magma ascent processes: Inferences from geophysical, structural, volcanological, and geochemical data for the Neapolitan volcanic region (southern Italy)

    Science.gov (United States)

    Piochi, Monica; Bruno, Pier Paolo; de Astis, Gianfilippo

    2005-07-01

    The Neapolitan volcanic region is located within the graben structure of the Campanian Plain (CP), which developed between the western sector of the Appenine Chain and the eastern margin of the Tyrrhenian Sea. Two volcanic areas, spaced less than 10 km apart, are situated within the CP: the Somma-Vesuvius Volcano (SVV) and the Phlegraean Volcanic District (PVD). SVV is a typical stratovolcano, whereas PVD, including Campi Flegrei, Procida, and Ischia, is composed mostly of monogenetic centers. This contrast is due to different magma supply systems: a widespread fissure-type system beneath the PVD and a central-type magma supply system for the SVV. Volcanological, geophysical, and geochemical data show that magma viscosity, magma supply rate, and depth of magma storage are comparable at PVD and SVV, whereas different structural arrangements characterize the two areas. On the basis of geophysical data and magma geochemistry, an oblique-extensional tectonic regime is proposed within the PVD, whereas in the SVV area a compressive stress regime dominates over extension. Geophysical data suggest that the area with the maximum deformation rate extends between the EW-running 41st parallel and the NE-running Magnaghi-Sebeto fault systems. The PVD extensional area is a consequence of the Tyrrhenian Sea opening and is decoupled from the surrounding areas (Roccamonfina and Somma-Vesuvius) which are still dominated by Adriatic slab dynamics. Spatially, we argue that the contribution of the asthenospheric wedge become much less important from W-NW to E-SE in the CP. The development of the two styles of volcanism in the CP reflects the different tectonic regimes acting in the area.

  20. Mapping saline water intrusion into the coastal aquifer with geophysical and geochemical techniques: the University of Lagos campus case (Nigeria).

    Science.gov (United States)

    Ayolabi, Elijah A; Folorunso, Adetayo F; Odukoya, Abiodun M; Adeniran, Adelere E

    2013-01-01

    Saltwater intrusion into the coastal aquifer, a phenomenon brought by the flow of seawater into freshwater aquifers originally caused by groundwater extraction near the coast, has long been recognised as a major concern around the world. In this study, we employed geophysical and geochemical techniques to map and provide evidences that the coastal aquifers in the study area have been intruded by saltwater from the adjacent Lagos lagoon. The resistivity data were acquired with an electrode spacing (a) that vary between 1.6 to 8 m, and expansion factor n of 30. The depth inverted models obtained from inversion of the fifteen resistivity data obtained in the area revealed significant impact of the lagoon water on the aquifers indicated as low resistivity usually below 7 Ωm. A combination of four different electrode arrays - Schlumberger, Wenner, Dipole-dipole and pole-dipole, with at least three deployed at each site ( except for three traverses - traverses 13, 14 and 15), yield better horizontal and vertical resolution, having depth range of 36-226 m with 1.6-8 m electrode spacing used. The delineated geoelectric layers were juxtaposed with logs from both boreholes located within the campus. Evidence from geochemical study of borehole and the lagoon water samples corroborated the ERT result. Progressive decrease in total dissolved solute (TDS) and electrical conductivity (EC) from the lagoon to the coastal aquifer buttresses gradual encroachment of the inland aquifers by the intruding lagoon water. In addition, similar trend was observed in heavy metal distribution Pollution Index (PI) plot suggesting possible underground flow of water from the lagoon to the aquifers. From this study, we deduced that excessive groundwater extraction and possibly the reduction of groundwater gradients which allows saline-water to displace fresh water in the aquifer of the investigated area are responsible for the saline water intrusion observed.

  1. Geophysical and geochemical constraints on the geodynamic origin of the Vrancea Seismogenic Zone Romania

    Science.gov (United States)

    Fillerup, Melvin A.

    The Vrancea Seismogenic Zone (VSZ) of Romania is a steeply NW-dipping volume (30 x 70 x 200 km) of intermediate-depth seismicity in the upper mantle beneath the bend zone of the Eastern Carpathians. The majority of tectonic models lean heavily on subduction processes to explain the Vrancea mantle seismicity and the presence of a Miocene age calc-alkaline volcanic arc in the East Carpathian hinterland. However, recent deep seismic reflection data collected over the Eastern Carpathian bend zone image an orogen lacking (1) a crustal root and (2) dipping crustal-scale fabrics routinely imaged in modern and ancient subduction zones. The DRACULA I and DACIA-PLAN deep seismic reflection profiles show that the East Carpathian orogen is supported by crust only 30-33 km thick while the Focsani basin (foreland) and Transylvanian basin (hinterland) crust is 42 km and 46 km thick respectively. Here the VSZ is interpreted as the former Eastern Carpathian orogenic root which was removed as a result of continental lithospheric delamination and is seismically foundering beneath the East Carpathian bend zone. Because large volumes of calc-alkaline volcanism are typically associated with subduction settings existing geochemical analyses from the Calimani, Gurghiu, and Harghita Mountains (CGH) have been reinterpreted in light of the seismic data which does not advocate the subduction of oceanic lithosphere. CGH rocks exhibit a compositional range from basalt to rhyolite, many with high-Mg# (Mg/Mg+Fe > 0.60), high-Sr (>1000 ppm), and elevated delta-O18 values (6-8.7 /) typical of arc lavas, and are consistent with mixing of mantle-derived melts with a crustal component. The 143Nd/144Nd (0.5123-0.5129) and 87Sr/86Sr (0.7040-0.7103) ratios similarly suggest mixing of mantle and crustal end members to obtain the observed isotopic compositions. A new geochemical model is presented whereby delamination initiates a geodynamic process like subduction but with the distinct absence of subducted

  2. Hydrogeological modeling constraints provided by geophysical and geochemical mapping of a chlorinated ethenes plume in northern France

    Science.gov (United States)

    Razafindratsima, Stephen; Guérin, Roger; Bendjoudi, Hocine; de Marsily, Ghislain

    2014-09-01

    A methodological approach is described which combines geophysical and geochemical data to delineate the extent of a chlorinated ethenes plume in northern France; the methodology was used to calibrate a hydrogeological model of the contaminants' migration and degradation. The existence of strong reducing conditions in some parts of the aquifer is first determined by measuring in situ the redox potential and dissolved oxygen, dissolved ferrous iron and chloride concentrations. Electrical resistivity imaging and electromagnetic mapping, using the Slingram method, are then used to determine the shape of the pollutant plume. A decreasing empirical exponential relation between measured chloride concentrations in the water and aquifer electrical resistivity is observed; the resistivity formation factor calculated at a few points also shows a major contribution of chloride concentration in the resistivity of the saturated porous medium. MODFLOW software and MT3D99 first-order parent-daughter chain reaction and the RT3D aerobic-anaerobic model for tetrachloroethene (PCE)/trichloroethene (TCE) dechlorination are finally used for a first attempt at modeling the degradation of the chlorinated ethenes. After calibration, the distribution of the chlorinated ethenes and their degradation products simulated with the model approximately reflects the mean measured values in the observation wells, confirming the data-derived image of the plume.

  3. Targeting of Gold Deposits in Amazonian Exploration Frontiers using Knowledge- and Data-Driven Spatial Modeling of Geophysical, Geochemical, and Geological Data

    Science.gov (United States)

    Magalhães, Lucíola Alves; Souza Filho, Carlos Roberto

    2012-03-01

    This paper reports the application of weights-of-evidence, artificial neural networks, and fuzzy logic spatial modeling techniques to generate prospectivity maps for gold mineralization in the neighborhood of the Amapari Au mine, Brazil. The study area comprises one of the last Brazilian mineral exploration frontiers. The Amapari mine is located in the Maroni-Itaicaiúnas Province, which regionally hosts important gold, iron, manganese, chromite, diamond, bauxite, kaolinite, and cassiterite deposits. The Amapari Au mine is characterized as of the orogenic gold deposit type. The highest gold grades are associated with highly deformed rocks and are concentrated in sulfide-rich veins mainly composed of pyrrhotite. The data used for the generation of gold prospectivity models include aerogeophysical and geological maps as well as the gold content of stream sediment samples. The prospectivity maps provided by these three methods showed that the Amapari mine stands out as an area of high potential for gold mineralization. The prospectivity maps also highlight new targets for gold exploration. These new targets were validated by means of detailed maps of gold geochemical anomalies in soil and by fieldwork. The identified target areas exhibit good spatial coincidence with the main soil geochemical anomalies and prospects, thus demonstrating that the delineation of exploration targets by analysis and integration of indirect datasets in a geographic information system (GIS) is consistent with direct prospecting. Considering that work of this nature has never been developed in the Amazonian region, this is an important example of the applicability and functionality of geophysical data and prospectivity analysis in regions where geologic and metallogenetic information is scarce.

  4. Geochemical and geophysical investigations, and fluid inclusion studies in the exploration area of Zafarghand (Northeast Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Zahra Alaminia

    2017-11-01

    Full Text Available Introduction Urumieh-Dokhtar Magmatic Arc (UDMA is a good prospective area for Cu, Cu-Mo and Cu-Au deposits (Fig. 1A and B. The Zafarghand district is located in the central part of the UDMA and the northeastern Isfahan. The present study concerns geological observations, alteration investigations, geochemical data and fluid inclusion studies. The purpose of the research is to identify geochemical anomalies and source of metals in this area. Geochemical anomalies for mineralizing elements and element associations were identified by using statistical analysis methods. Additionally, these results together suggest a site for exploration drilling in this study area. Materials and methods We collected 186 samples (rock along multi-cross sections oriented perpendicular to the strike of the South -Ardestan fault (Fig. 2.Trace element concentrations were determined by the ICP-MS technique in Amdel laboratory (Australia. Thin sections and doubly polished sections (100–200 µm thick from quartz veins were prepared from samples collected from the Zafarghand district in the University of Isfahan. Heating and freezing experiments on fluid inclusions were performed as defined (by Goldstein and Reynolds (1994 on a Linkam THM600 stage. Results Igneous rocks in the Zafarghand area are dominated by the Eocene and post Eocene acidic-intermediate rocks that include dacite, rhyodacite and andesite associated with diorite, quartz diorite and microdiorite intrusions. The present investigations indicate that all rocks of the Zafarghand district exhibit a variety of alterations. Hydrothermal alterations include phyllic, potassic, silicification, and argillic with widespread propylitic. The mineralization consists of malachite, azurite, hematite, and goethite, rare amounts of magnetite, pyrite, and chalcopyrite. Numerical traditional statistical analysis techniques have been applied to interpret the geochemical data of the study area. These methods are aimed at

  5. Surface geochemical data evaluation and integration with geophysical observations for hydrocarbon prospecting, Tapti graben, Deccan Syneclise, India

    Directory of Open Access Journals (Sweden)

    T. Satish Kumar

    2014-05-01

    Full Text Available The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significant hydrocarbon discoveries, particularly for Mesozoic sequences, have not been established through conventional exploration due to the thick basalt cover over Mesozoic sedimentary rocks. In this study, near-surface geochemical data are used to understand the petroleum system and also investigate type of source for hydrocarbons generation of the study area. Soil samples were collected from favorable areas identified by integrated geophysical studies. The compositional and isotopic signatures of adsorbed gaseous hydrocarbons (methane through butane were used as surface indicators of petroleum micro-seepages. An analysis of 75 near-surface soil-gas samples was carried out for light hydrocarbons (C1–C4 and their carbon isotopes from the western part of Tapti graben, Deccan Syneclise, India. The geochemical results reveal sites or clusters of sites containing anomalously high concentrations of light hydrocarbon gases. High concentrations of adsorbed thermogenic methane (C1 = 518 ppb and ethane plus higher hydrocarbons (ΣC2+ = 977 ppb were observed. Statistical analysis shows that samples from 13% of the samples contain anomalously high concentrations of light hydrocarbons in the soil-gas constituents. This seepage suggests largest magnitude of soil gas anomalies might be generated/source from Mesozoic sedimentary rocks, beneath Deccan Traps. The carbon isotopic composition of methane, ethane and propane ranges are from −22.5‰ to −30.2‰ PDB, −18.0‰ to 27.1‰ PDB and 16.9‰–32.1‰ PDB respectively, which are in thermogenic source. Surface soil sample represents the intersection of a migration conduit from the deep subsurface to the surface connected to sub-trappean Mesozoic sedimentary rocks. Prominent hydrocarbon concentrations were associated with dykes, lineaments and presented on thinner basaltic cover in the study area

  6. Development of a Model of Geophysical and Geochemical Controls on Abiotic Carbon Cycling on Earth-Like Planets

    Science.gov (United States)

    Neveu, M.; Felton, R.; Domagal-Goldman, S. D.; Desch, S. J.; Arney, G. N.

    2017-12-01

    About 20 Earth-sized planets (0.6-1.6 Earth masses and radii) have now been discovered beyond our solar system [1]. Although such planets are prime targets in the upcoming search for atmospheric biosignatures, their composition, geology, and climate are essentially unconstrained. Yet, developing an understanding of how these factors influence planetary evolution through time and space is essential to establishing abiotic backgrounds against which any deviations can provide evidence for biological activity. To this end, we are building coupled geophysical-geochemical models of abiotic carbon cycling on such planets. Our models are controlled by atmospheric factors such as temperature and composition, and compute interior inputs to atmospheric species. They account for crustal weathering, ocean-atmosphere equilibria, and exchange with the deep interior as a function of planet composition and size (and, eventually, age).Planets in other solar systems differ from the Earth not only in their bulk physical properties, but also likely in their bulk chemical composition [2], which influences key parameters such as the vigor of mantle convection and the near-surface redox state. Therefore, simulating how variations in such parameters affect carbon cycling requires us to simulate the above processes from first principles, rather than by using arbitrary parameterizations derived from observations as is often done with models of carbon cycling on Earth [3] or extrapolations thereof [4]. As a first step, we have developed a kinetic model of crustal weathering using the PHREEQC code [5] and kinetic data from [6]. We will present the ability of such a model to replicate Earth's carbon cycle using, for the time being, parameterizations for surface-interior-atmosphere exchange processes such as volcanism (e.g., [7]).[1] exoplanet.eu, 7/28/2017.[2] Young et al. (2014) Astrobiology 14, 603-626.[3] Lerman & Wu (2008) Kinetics of Global Geochemical Cycles. In Kinetics of Water

  7. A Combined Hydrological, Geochemical and Geophysical Reconnaissance of Groundwater Contamination In Oilfield Environment (republic of Tatarstan, Russia)

    Science.gov (United States)

    Levitski, A.; Titov, K.; Buès, M.; Ilyin, Yu.; Konosavski, P.; Kharkhordin, I.; Uchaev, V.; Sapozhnikov, B.; Kharkovski, K.

    Numerous brine leakages from production and injection wells and pipelines were ob- served at the site of study situated in Romashkinskoye oilfield. The groundwater flow, which follows the relief, is manifested by five springs. The salinity of these springs significantly increased during 20 years of oil exploitation at the site. The subsurface consists of sandstone, clayey sandstone, siltstone and limestone. Sampling of spring water and soils, as well as geophysical investigations, were carried out to develop the groundwater and contamination flow model of the site. In addition to the traditional bulk soil sampling, the mobile forms of chemical elements were investigated using the diffusion sampling technique (Levitski et al., 1995). The dipole-dipole resistivity and Spontaneous Polarization (SP) maps of the site were obtained. One prospecting bore- hole of 40 m was sunk. Vertical Electrical Sounding (VES) and Time Domain Spec- tral Induced Polarization Sounding (SIP), conducted at several points, were inverted to obtain rock and soil resistivity. The SIP measurements were performed to help geo- logical interpretation of the obtained resistivity cross-sections. The groundwater flow model was developed on the basis of borehole data, debits of the observed springs, and surface geophysical data. The model was calibrated using numerical modelling of SP. The 2D program GWFGEM based on the SillSs approach (1983) was applied. First, the preliminary groundwater flow model was obtained. Based on the coupling flow theory, sources of SP were calculated from water heads. Then, SP was calculated on the basis of SP sources and subsurface resistivity derived from the VES inversion. The above procedure was repeated several times to minimise the discrepancy between the observed and calculated SP. The flow balance for the whole site was obtained. The best indicators of the oil-related contamination at the site were found to be: (1) in groundwater U K, Na and Sr; (2) in bulk soil U Ca

  8. Geophysical and geochemical exploration research on basic metallogenic conditions of unconformity-related uranium deposits in the south part of Kangdian earth's axis

    International Nuclear Information System (INIS)

    Zhang Shucheng; Bai Yunsheng; Wu Huishan; Wu Yue; Chang Guilan

    2001-01-01

    In order to find out the unconformity-related large and super large uranium-rich deposits and to explore the prospecting model for the unconformity-related uranium deposits, the geophysical and geochemical exploration on the basic metallogenic conditions of the unconformity-related uranium deposits in the south part of the Kangdian earth's axis has been carried out after the investigation and research into large amounts of information in combination with the analysis and contrasts of the aeromagnetic, aero-radiometric and gravity data. On the basis of synthesizing the airborne survey information, land-based geophysical and geochemical exploration, the physical nature of many types of rocks and the multi-element analytical and determining results of the U, Th, Au, Cu in the soil samples, the geophysical prospecting models on the unconformity-related uranium deposits in this area has been put forward, and two uranium metallogenic prospect areas and one uranium metallogenic prospect belt have been divided. These results have laid a good foundation for finding out the unconformity-related uranium deposits in this area

  9. A geophysical and geochemical investigation of the Kalang-Anyar mud volcano, Indonesia.

    Science.gov (United States)

    Husein, Alwi; Mazzini, Adriano; Lupi, Matteo; Sciarra, Alessandra; Karyono, Karyono

    2017-04-01

    The northest Java region is a sedimentary basin as well as a promising hydrocarbon province. Like other similar setting, the region is characterized by diffused mud volcanism and degassing sites. In the Sidoarjo province extends the Watukosek Fault system that connects the Javanese Arjuno-Welirang Volcanic arc to the back-arc basin in North East Java. Along this fault systems can be identified several mud volcanoes including the spectacular Lusi mud eruption site. Approximately 40 km NE of Lusi is located the Kalang Anyar mud volcano that was target for a multidisciplinary study to understand its activity as well as the plumbing system. We combined geoelectrical, gas sampling and mapping studies and seismic monitoring. The geoelectrical data show low resistivity values (CO2 flux profiles were conducted through the active crater area and extending towards the outskirts. Results shows anomalous high values of the gasses in the summit region revealing a methane dominated diffused degassing throughout the structure. The seismic data show a drumbeat signal in the high-frequency range (i.e. between 5 Hz and 30 Hz) occurring on all the seismic stations. The signal is most pronounced on the seismic station closer to the most active emission vent. Such seismic signal is seen at regular intervals varying from about 40 s to 120 s.

  10. Geophysical and geochemical studies to delineate seawater intrusion in Bagoush area, Northwestern coast, Egypt

    Science.gov (United States)

    Eissa, Mustafa A.; Mahmoud, Hussein Hosni; Shouakar-Stash, Orfan; El-Shiekh, Abdelfattah; Parker, Beth

    2016-09-01

    Coastal aquifers are the main source for sustainable freshwater in many arid and semi-arid regions around the earth. In such regions, groundwater extraction far exceeds the natural replenishment rates due to additional demands on groundwater resources especially in the last few decades. The characterization of the seawater intrusion in the Baghoush area along the northwestern coast of Egypt assesses the risk of seawater intrusion for the purpose of managing the groundwater resources in coastal areas. The (SI) in the oolitic Pleistocene aquifer is affected by several natural factors, including the drainage patterns, geological structures, distance from the sea and the manipulation of groundwater. Electrical Resistivity Tomography (ERT) has been implemented to identify the geometry of the brackish/saline water interface and to map the distribution of brackish water zone floating over the denser saline water. Seven 2-D resistivity imaging profiles were conducted using a Wenner array with different electrode distance spacings. The inverse resistivity models of these profiles indicate that these profiles are composed of three zones: the upper dry zone, the middle brackish water zone, and the lower saline water zone. The thickness of the brackish groundwater zone decreases toward the sea and the resistivity decreases with depth due to increase in water salinity. Water table along these profiles decreases from south to north, which indicates that groundwater flow is from south (inland) to north (sea). Groundwater chemistry and stable isotopes were used to determine the fresh groundwater recharge source(s), to identify mixing of different groundwaters, to evaluate seawater intrusion zone along the coast, and to investigate the upwelling of deep saline groundwater underneath the brackish zone. The recharge of fresh groundwater originates from the mountain watershed located upstream as well as the annual rainfall; however, seawater is the main source of groundwater

  11. ELECTRE III: A knowledge-driven method for integration of geophysical data with geological and geochemical data in mineral prospectivity mapping

    Science.gov (United States)

    Abedi, Maysam; Torabi, Seyed Ali; Norouzi, Gholam-Hossain; Hamzeh, Mohammad

    2012-12-01

    This paper describes the application of a multicriteria decision-making (MCDM) technique called ELECTRE III, which is well-known in operations research, to mineral prospectivity mapping (MPM), which involves representation and integration of evidential map layers derived from geological, geophysical, and geochemical geo-data sets. In a case study, thirteen evidential map layers are used for MPM in the area containing the Now Chun copper prospect in the Kerman province of Iran. The ELECTRE III technique was applied for MPM, and the outputs are validated using 3D models of Cu and Mo concentrations from 21 drill hole data. This proposed method shows high performance for MPM.

  12. Geophysical and Geochemical Aspects of Pressure and CO2 Saturation Modeling due to Migration of Fluids into the Above Zone Monitoring Interval of a Geologic Carbon Storage Site

    Science.gov (United States)

    Zhang, L.; Namhata, A.; Dilmore, R. M.; Bromhal, G. S.

    2016-12-01

    An increasing emphasis on the industrial scale implementation of CO2 storage into geological formations has led to the development of whole-system models to evaluate performance of candidate geologic storage sites, and the environmental risk associated with them. The components of that engineered geologic system include the storage reservoir, primary and secondary seals, and the overlying formations above primary and secondary seals (above-zone monitoring interval, AZMI). Leakage of CO2 and brine through the seal to the AZMI may occur due to the presence of natural or induced fractures in the seal. In this work, an AZMI model that simulates pressure and CO2 saturation responses through time to migration of fluids (here, CO2 and brine) from the primary seal to the AZMI is developed. A hypothetical case is examined wherein CO2 is injected into a storage reservoir for 30 years and a heterogeneous primary seal exists above the reservoir with some permeable zones. The total simulation period is 200 years (30 years of CO2 injection period and 170 years of post CO2 injection period). Key geophysical parameters such as permeability of the AZMI, thickness of the AZMI and porosity of the AZMI have significant impact on pressure evolution in the AZMI. arbitrary Polynomial Chaos (aPC) Expansion analysis shows that permeability of the AZMI has the most significant impact on pressure build up in the AZMI above the injection well at t=200 years, followed by thickness of the AZMI and porosity of the AZMI. Geochemical reactions have no impact on pressure and CO2 saturation evolution in the AZMI during the CO2 injection period. After the CO2 injection stops, precipitation of secondary minerals (e.g., amorphous silica and kaolinite) at the CO2 plume/brine interface in the AZMI formation may cause permeability reduction of the AZMI, which restrains horizontal migration of CO2 in the AZMI.

  13. Surface geochemical data evaluation and integration with geophysical observations for hydrocarbon prospecting, Tapti graben, Deccan Syneclise, India

    OpenAIRE

    Satish Kumar, T.; Dayal, A.M.; Sudarshan, V.

    2014-01-01

    The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significant hydrocarbon discoveries, particularly for Mesozoic sequences, have not been established through conventional exploration due to the thick basalt cover over Mesozoic sedimentary rocks. In this study, near-surface geochemical data are used to understand the petroleum system and also investigate type of source for hydrocarbons generation of the study area. Soil samples were collected from favorable...

  14. pplication of Fractal Technique for Analysis of Geophysical - Geochemical Databases in Tekieh Pb-Zn Ore Deposit (SE of Arak)

    OpenAIRE

    Seyed Reza Mehrnia

    2017-01-01

    Introduction Tekieh Lead-Zinc ore deposit that is located in the Sanandaj-Sirjan structural zone has been recognized as one of the most important mineralized regions in Malayer-Isfahan metallogenic sub-state, south east of Arak (Momenzadeh and Ziseman, 1981). Carbonate host units have been developed along (or across) the Vishan-Tekieh anticline as the main structure extended in NW-SE trends (Annells et al, 1985). According to geochemical investigations (Salehi, 2004), the element content o...

  15. Geophysical and Geochemical Analysis of the 8°20' N Seamount Chain: Studies of Off-Axis Volcanism

    Science.gov (United States)

    McCully, E.; Fornari, D. J.; Gregg, P. M.; Perfit, M. R.; Wanless, V. D.; Anderson, M.; Lubetkin, M.

    2017-12-01

    The 8°20' N Seamount Chain is an off-axis lineament of volcanoes located west of the East Pacific Rise (EPR) and 15 km north of the Siqueiros Fracture Zone. The volcanoes are located 11 km west of the EPR axis and extend 160 km to the west. The OASIS (Off-Axis Seamount Investigations at Siqueiros) expedition in November 2016 collected ship-based EM122 bathymetry aboard the R/V Atlantis over the entire seamount chain at a 50 m resolution, and AUV Sentry bathymetric and sidescan sonar data were collected over 11 selected areas on some of the seamount summits and flanks at 1-2 m resolution. 90,000 high-resolution digital images were acquired using DSV Alvin and analyzed and classified according to morphology, structure, sediment and manganese presence, and biology. These data are used to create geologic facies maps to correlate seafloor morphology and type with acoustic reflectivity. Major and trace element data of samples collected by Alvin and dredging are also correlated to geological parameters of the seafloor features on each studied seamount. Initial estimates for the volumes of individual constructional features (e.g., mounds, cones) that comprise the seamounts were derived from the high-resolution EM122 multibeam and Sentry AUV bathymetric data and calculated using IVS Fledermaus and plotted as a function of distance from the EPR. These individually constructed volcanic features, dependent on geochemical diversity, may ultimately be grouped into larger eruptive volumes. Thus far, Sentry-derived volumes range from 0.0011-2.96 km3, while EM122-derived volumes range from 0.13-123 km3. The seamounts were classified into 3 shapes; circular, volcanic lineaments aligning parallel to the ridge-axis, and ridge-like constructions, trending perpendicular to the EPR axis. The central 60 km of the chain (60-120 km off-axis) is dominated by ridges and circular seamounts, which exhibit the largest volumes observed along the 8°20' N chain. The seamounts with the lowest

  16. Geochemical and Geophysical Study in a Degraded Area Used for Disposal of Sludge from a Water Treatment Plant

    Directory of Open Access Journals (Sweden)

    Ricardo Cosme Arraes Moreira

    2011-01-01

    Full Text Available The effects of disposal of sludge from water treatment plant (WTS in area damaged by laterite extraction and its consequences to soil and groundwater were investigated. Therefore, the presence and concentration of anthropogenic elements and chemical compounds were determinated. WTS disposal's influence was characterized by electroresistivity method. The WTS's geochemical dispersion was noticed in the first meters of the nonsaturated zone from the lending area. Lateritic profiles were characterized due to the large variation in chemical composition between the horizons. Infiltration and percolation of rainwater through the WTS have caused migration of total dissolved solids to the groundwater. WTS's disposing area has more similarities to local preserved vegetation than to gravel bed area. WTS can be considered a noninert residue if disposed in degraded areas located in regions with similar geological and hydrochemical characteristics.

  17. Final Report: Improved Site Characterization And Storage Prediction Through Stochastic Inversion Of Time-Lapse Geophysical And Geochemical Data

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A; Mcnab, W; Hao, Y; White, D; Johnson, J

    2011-04-14

    During the last months of this project, our project activities have concentrated on four areas: (1) performing a stochastic inversion of pattern 16 seismic data to deduce reservoir bulk/shear moduli and density; the need for this inversion was not anticipated in the original scope of work, (2) performing a stochastic inversion of pattern 16 seismic data to deduce reservoir porosity and permeability, (3) complete the software needed to perform geochemical inversions and (4) use the software to perform stochastic inversion of aqueous chemistry data to deduce mineral volume fractions. This report builds on work described in progress reports previously submitted (Ramirez et al., 2009, 2010, 2011 - reports fulfilled the requirements of deliverables D1-D4) and fulfills deliverable D5: Field-based single-pattern simulations work product. The main challenge with our stochastic inversion approach is its large computational expense, even for single reservoir patterns. We dedicated a significant level of effort to improve computational efficiency but inversions involving multiple patterns were still intractable by project's end. As a result, we were unable to fulfill Deliverable D6: Field-based multi-pattern simulations work product.

  18. Early Cretaceous Tertiary magmatism in Eastern Paraguay (western Paraná basin): geological, geophysical and geochemical relationships

    Science.gov (United States)

    Comin-Chiaramonti, P.; Cundari, A.; DeGraff, J. M.; Gomes, C. B.; Piccirillo, E. M.

    1999-11-01

    Structural characteristics of Eastern Paraguay, at the westernmost side of the Paraná basin, show that the tectonics in the region is extensional. This tectonics controlled the emplacement of the alkaline rocks in Early Cretaceous-Tertiary times. Major structures are NW-trending zones of tectonic subsidence, i.e. the 'Asunción-Sapucai-Villarrica' and 'Amambay' grabens of the central and northeastern regions of Eastern Paraguay, respectively. Early Cretaceous potassic magmatism is widespread in the 'gravity lows', and predates the tholeiitic Early Cretaceous magmatism in the northern areas, whereas in central Paraguay it postdates the tholeiitic flood basalts. Sodic alkaline rocks (late Early Cretaceous-Tertiary) are widespread in cratonized areas of the La Plata Craton. The Early Cretaceous uncontaminated potassic rocks (and tholeiites) have geochemical features of 'subduction type' (e.g. Ta-Nb negative anomaly), while the contrary occurs for the closely associated younger sodic magmatism. This implies different mantle sources consistently with Sr-Nd isotopes which are Rb-Nd enriched and depleted for the potassic and sodic rocks, respectively. T DM(Nd) model ages point to two notional distinct metasomatic events occurred in Middle and Late Proterozoic times. A contribution of asthenospheric melts from Tristan da Cunha Plume is not appreciable. We suggest that the source(s) of the recurrent potassic magmatism and interposed tholeiitic event may not be easily accounted for by the Tristan da Cunha plume hypothesis.

  19. Progress Report, December 2010: Improved Site Characterization And Storage Prediction Through Stochastic Inversion Of Time-Lapse Geophysical And Geochemical Data

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A; Mcnab, W; Carle, S; Hao, Y; White, D; Johnson, J

    2010-12-17

    predicted seismic response. The software that implements this approach has been completed, tested, and used to process seismic data from pattern 16. A previously submitted report titled ''Model verification: synthetic single pattern simulations using seismic reflection data'', Ramirez et al. 2010, partially fulfilled deliverable D3 by summarizing verification activities that evaluate the performance of the seismic software and its ability to recover reservoir model permeabilities using synthetic seismic reflection data. A future progress report will similarly describe summarizing verification activities of the geochemical inversion software, thereby completing deliverable D3. This document includes a chapter that shows and discusses permeability models produced by seismic inversion that used seismic data from pattern 16 in Phase 1A. It partially fulfills deliverable D5: Field-based single-pattern simulations work product. The D5 work product is supposed to summarize the results of applying NUFT/MCMC to refine the reservoir model and geochemical parameters by optimizing observation/prediction agreement for the seismic/geochemical response to CO{sub 2} injection/migration within a single pattern of Phase 1A/1B. A future progress report will show inversion results for the same pattern using geochemical data, thereby completing deliverable D5. This document also contains a chapter that fulfills deliverable D2: Model development: MCMC tool (synthetic fluid chemistry data). The chapter will summarize model development activities required to facilitate application of NUFT/MCMC to optimize agreement between the observed and predicted geochemical response to CO{sub 2} injection/migration. Lastly, this document also contains a chapter that partially fulfills deliverable D4: Model development/verification: MCMC tool (TProGS, field seismic/chemistry data) work product. This work product is supposed to summarize model development activities required for (1

  20. Blind Geothermal System Exploration in Active Volcanic Environments; Multi-phase Geophysical and Geochemical Surveys in Overt and Subtle Volcanic Systems, Hawai’i and Maui

    Energy Technology Data Exchange (ETDEWEB)

    Fercho, Steven [Ormat Nevada, Inc., Reno, NV (United States); Owens, Lara [Ormat Nevada, Inc., Reno, NV (United States); Walsh, Patrick [Ormat Nevada, Inc., Reno, NV (United States); Drakos, Peter [Ormat Nevada, Inc., Reno, NV (United States); Martini, Brigette [Corescan Inc., Ascot (Australia); Lewicki, Jennifer L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kennedy, Burton M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-08-01

    Suites of new geophysical and geochemical exploration surveys were conducted to provide evidence for geothermal resource at the Haleakala Southwest Rift Zone (HSWRZ) on Maui Island, Hawai’i. Ground-based gravity (~400 stations) coupled with heli-bourne magnetics (~1500 line kilometers) define both deep and shallow fractures/faults, while also delineating potentially widespread subsurface hydrothermal alteration on the lower flanks (below approximately 1800 feet a.s.l.). Multi-level, upward continuation calculations and 2-D gravity and magnetic modeling provide information on source depths, but lack of lithologic information leaves ambiguity in the estimates. Additionally, several well-defined gravity lows (possibly vent zones) lie coincident with magnetic highs suggesting the presence of dike intrusions at depth which may represent a potentially young source of heat. Soil CO2 fluxes were measured along transects across geophysically-defined faults and fractures as well as young cinder cones along the HSWRZ. This survey generally did not detect CO2 levels above background, with the exception of a weak anomalous flux signal over one young cinder cone. The general lack of observed CO2 flux signals on the HSWRZ is likely due to a combination of lower magmatic CO2 fluxes and relatively high biogenic surface CO2 fluxes which mix with the magmatic signal. Similar surveys at the Puna geothermal field on the Kilauea Lower East Rift Zone (KLERZ) also showed a lack of surface CO2 flux signals, however aqueous geochemistry indicated contribution of magmatic CO2 and He to shallow groundwater here. As magma has been intercepted in geothermal drilling at the Puna field, the lack of measured surface CO2 flux indicative of upflow of magmatic fluids here is likely due to effective “scrubbing” by high groundwater and a mature hydrothermal system. Dissolved inorganic carbon (DIC) concentrations, δ13C compositions and 3He/4He values were sampled at Maui from several shallow

  1. Geostatistical Interplay Between Geophysical and Geochemical Data: Mapping Litho-Structural Assemblages of Mesozoic Igneous Activities in the Parnaíba Basin (NE Brazil)

    Science.gov (United States)

    de Castro, David L.; Oliveira, Diógenes C.; Hollanda, Maria Helena B. M.

    2018-02-01

    Two widespread magmatic events are recorded in the Parnaíba basin (NE Brazil) during the Jurassic/Cretaceous opening of the Central and South Atlantic Oceans. The Early Jurassic ( 200 Ma) lava flows of the Mosquito Formation occur essentially in the western and southern basin segments, representing one of the largest expressions of the Central Atlantic Magmatic Province in the South American Plate. In contrast, sill complexes and dike swarms of the Early Cretaceous (129-124 Ma) Sardinha Formation occur in the eastern part of the basin and are chrono-correlated to the large Paraná-Etendeka igneous province and to the Rio Ceará-Mirim Dike Swarm. We gathered geophysical, well logging, outcrop analogs and geochemical data to recognize geometrical shapes and areal distribution patterns of igneous-related constructions. Seismic and well data reveal hundreds of km wide multilayered sill complexes and dikes, which are widespread across vast regions of the basin without evident structural control from either the Precambrian basement grain or the basin internal architecture. Anomaly enhancement techniques and self-organizing maps (SOM) procedure were applied on airborne magnetic data, unraveling near-surface magmatic features in four distinct magnetic domains. Using SOM analysis, the basaltic rocks were divided into six groups based on magnetic susceptibility and major elements composition. These results suggest common origin for both magmatic episodes, probably a combination of effects of edge-driven convection and large-scale mantle warming under the westward moving West Gondwana during the Central and South Atlantic opening, which caused a shifted emplacement to the east of the igneous rocks in the Parnaíba basin.

  2. Expanding Geophysical and Geochemical Investigation of Causes of Extraordinary Unrest at the Laguna del Maule (Rhyolitic) Volcanic Field, Southern Andes, Chile

    Science.gov (United States)

    Singer, B. S.

    2014-12-01

    The Laguna del Maule Volcanic Field, Chile, includes an unusually large and recent concentration of silicic eruptions. Since 2007 the crust here has been inflating at an astonishing rate of 25 cm/yr. Findings thus far lead to the hypothesis that the silicic vents have tapped an extensive layer of crystal-poor, rhyolitic melt that began to form atop a magmatic mush zone that was established by ~20 ka with a renewed phase of rhyolite eruptions during the Holocene. Modeling of surface deformation, magnetotelluric data, and gravity changes suggest that magma is currently intruding at a depth of ~5 km. Swarms of volcano-tectonic and long period earthquakes, mostly of M San Juan-Argentina, Nanyang Technological University-Singapore, SERNAGEOMIN, OVDAS, USGS, and SEGEMAR-Argentina. Team members will be introduced in this presentation. Our approach includes augmenting the OVDAS array of 6 permanent seisic stations with 40 additional instruments to conduct tomographic, receiver function and ambient noise studies. We continue to collect 4-D gravity data from 37 stations. Surface deformation is monitored via cGPS at 5 permanent receivers and InSAR data. A magnetotelluric survey across the Andes at 36o S is planned. Geochemical studies include mineral zoning and U-Th disequilibrium of zircons to constrain the timing of magma intrusion and mixing events prior to the current unrest. The overall aim is to integrate these observations and to construct numerical models of system dynamics. We are developing communications protocols and a web site to facilitate sharing of findings among the team members and with the public.

  3. Environmental Geophysics

    Science.gov (United States)

    The Environmental Geophysics website features geophysical methods, terms and references; forward and inverse geophysical models for download; and a decision support tool to guide geophysical method selection for a variety of environmental applications.

  4. Massive sulfide exploration models of the Iberian Pyrite Belt Neves Corvo mine region, based in a 3D geological, geophysical and geochemical ProMine study

    Science.gov (United States)

    Inverno, Carlos; Matos, João Xavier; Rosa, Carlos; Mário Castelo-Branco, José; Granado, Isabel; Carvalho, João; João Baptista, Maria; Represas, Patrícia; Pereira, Zélia; Oliveira, Tomás; Araujo, Vitor

    2013-04-01

    The Iberian Pyrite Belt (IPB) hosts one of the largest concentrations of massive sulfides in the Earth's crust. This highly productive VMS belt contains more than 85 massive sulfide deposits, totalling an estimate of 1600 Mt of massive ore and about 250 Mt of stockwork ore (Leistel et al., 1998; Oliveira et al., 2005; Tornos, 2006). Included in the South Portuguese Zone the IPB is represented by the Phyllite-Quartzite Group (PQG) composed of shales and quartzites of late Devonian age followed by the Volcanic-Sedimentary Complex (VSC) a submarine succession of sediments and felsic and basic volcanic rocks (late Famennian-late Viséan age). Above the IPB a turbidite sedimentary unit occurs being represented by the Baixo Alentejo Flysch Group (BAFG). The ore deposits are hosted by felsic volcanic rocks and sediments that are dominant in the lower part of the VSC succession. The Neves Corvo (ProMine, EU FP7) project area is focused on the Neves Corvo deposit, an active copper mine. The project area is located between the Messejana Fault and the Portuguese/Spanish border which has been selected for the 3D geological and geophysical modelling study, based on high exploration potential of the Neves Corvo area (Oliveira et al. 2006, Relvas et al. 2006, Pereira et al. 2008, Rosa et al. 2008, Matos et al. 2011, Oliveira et al. 2013). In this study existing LNEG and AGC geological, geophysical and geochemistry databases were considered. New surveys were done: i) - A physical volcanology and palynostratigraphic age data study and log of the Cotovio drill-hole core (1,888 m, drilled by AGC). ii) - Interpretation of 280 km of Squid TEM performed by AGC. Based on the TEM data, significant conductors have been identified related with: shallow conductive cover, graphitic shale, black shale and sulphide mineralizations. The most important TEM conductors are related with the Neves Corvo massive sulphides lenses (1-10 Ωm). iii) - Ground and residual gravimetry studies including

  5. A geochemical and geophysical approach to derive a conceptual circulation model of CO2-rich mineral waters: A case study of Vilarelho da Raia, northern Portugal

    Science.gov (United States)

    Marques, J. M.; Santos, Monteiro; Graça, R. C.; Castro, R.; Aires-Barros, L.; Mendes Victor, L. A.

    2001-11-01

    The Vilarelho da Raia-Chaves region, located in northern Portugal adjacent to the Spanish border, is characterized by both hot and cold CO2-rich mineral waters issuing from springs and drilled wells. The present paper updates the conceptual circulation model of the Vilarelho da Raia cold CO2-rich mineral waters. Vilarelho da Raia mineral waters, dominated by Na and HCO3 ions, have formed mainly by interaction with CO2 of deep-seated mantle origin. The δ18O, δ2H and 3H values indicate that these waters are the result of meteoric waters infiltrating into Larouco Mountain, NW of Vilarelho da Raia, circulating at shallow depths in granitic rocks and moving into Vilarelho da Raia area. The conceptual geochemical and geophysical circulation model indicates that the hot and cold CO2-rich mineral waters of Chaves (76 °C) and Vilarelho da Raia (17 °C) should be considered manifestations of similar but not the same geohydrological systems. Résumé. La région de Vilarelho da Raia - Chaves, située au Portugal près de la frontière Espagnole, est caractérisée par des eaux carbogazeuses, chaudes et froides, émergeant à des sources et dans des puits. Ce travail constitue une mise au point du modèle conceptuel de circulation des eaux minérales carbogazeuses froides de Vilarelho da Raia. Les eaux minérales de Vilarelho da Raia, dans lesquelles les ions Na and HCO3 sont dominants, résultent principalement d'interactions avec du CO2 d'origine mantellique. Les δ18O, les δ2H, et les teneurs en 3H indiquent que ces eaux proviennent de l'infiltration d'eaux météoriques dans le Mont Larouco au NW de Vilarelho da Raia, circulant à faible profondeur dans les granites en direction de la région de Vilarelho da Raia. Le modèle de circulation géochimique et géophysique conduit à penser que les eaux minérales carbogazeuses chaudes et froides de Chaves (76 °C) et de Vilarelho da Raia (17 °C) doivent être considérées comme des manifestations de systèmes hydrog

  6. Mineralogical and Geochemical Studies of Bone Detritus of Pleistocene Mammals, Including the Earliest in Northern Eurasia Humans

    Directory of Open Access Journals (Sweden)

    V. I. Silaev

    2015-12-01

    Full Text Available Article presents the preliminary results of mineralogical and geochemical studies of the primary and epigenetic properties of the bio-mineral and protein components in the fossil bone detritus as an example of first step of continued interdisciplinary research program. During the further implementation of this program, it is expected not only to solve a set of interrelated mineralogical, paleontological, paleoecological, paleoclimatic, and archaeological problems, but also to obtain new knowledge about the coevolution of organic, organo-mineral and inorganic substances in the geological history. The main objects of study are the fossil remains of the large Pleistocene mammals (mammoths, woolly rhinoceroses, deer, elk, horses, bison, cave and brown bear found on the territory of the Pechora Urals (62-67 ° N , South Pri-Irtyshie in Western Siberia (57-58 ° N, and Northern Taymyr (75-77 ° N. The oldest bone of Homo sapiens (Ust-Ishim human found in Northern Eurasia and remains of medieval Tobol and Irtysh Turk will be investigated as well. The results of previous studies of skin and hair of biological material from today's wild fisheries (analogues Pleistocene mammals, wild and domestic animals are considered as the reliable prerequisites for planned isotopic and geochemical studies. Use of cutting-edge research techniques will allow determining the chemical composition of bones; the elemental composition of bone collagen and bone proteins; the degree of crystallinity of bone bioapatite, and phase composition of xenomineral impurities; the isotopic composition of carbon, oxygen, and nitrogen in bioapatite and collagen; the actual molecular and crystal structure of the protein biomineral, and bone substance; the concentration of trace elements; the conditions and duration of burial and reburial of bone detritus; bone collagen bacterial degradation at an early stage of fossilization. It is expected that the implementation of the proposed project

  7. Handbook of Agricultural Geophysics

    Science.gov (United States)

    Geophysical methods continue to show great promise for use in agriculture. The term “agricultural geophysics” denotes a subdiscipline of geophysics that is focused only on agricultural applications. The Handbook of Agricultural Geophysics was compiled to include a comprehensive overview of the geoph...

  8. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    Science.gov (United States)

    Abbas, M.; Jardani, A.

    2015-12-01

    The task of delineating the contamination plumes as well as studying their impact on the soil and groundwater biogeochemical properties is needed to support the remediation efforts and plans. Geophysical methods including electrical resistivity tomography (ERT), induced polarization (IP), ground penetrating radar (GPR), and self-potential (SP) have been previously used to characterize contaminant plumes and investigate their impact on soil and groundwater properties (Atekwana et al., 2002, 2004; Benson et al., 1997; Campbell et al., 1996; Cassidy et al., 2001; Revil et al., 2003; Werkema et al., 2000). Our objective was to: estimate the hydrocarbon contamination extent in a contaminated site in northern France, and to adverse the effects of the oil spill on the groundwater properties. We aim to find a good combination of non-intrusive and low cost methods which we can use to follow the bio-remediation process, which is planned to proceed next year. We used four geophysical methods including electrical resistivity tomography, IP, GPR, and SP. The geophysical data was compared to geochemical ones obtained from 30 boreholes installed in the site during the geophysical surveys. Our results have shown: low electrical resistivity values; high chargeability values; negative SP anomalies; and attenuated GPR reflections coincident with groundwater contamination. Laboratory and field geochemical measurements have demonstrated increased groundwater electrical conductivity and increased microbial activity associated with hydrocarbon contamination of groundwater. Our study results support the conductive model suggested by studies such as Sauck (2000) and Atekwana et al., (2004), who suggest that biological alterations of hydrocarbon contamination can substantially modify the chemical and physical properties of the subsurface, producing a dramatic shift in the geo-electrical signature from resistive to conductive. The next stage of the research will include time lapse borehole

  9. Geophysical, geochemical and hydrological analyses of water-resource vulnerability to salinization: case of the Uburu-Okposi salt lakes and environs, southeast Nigeria

    Science.gov (United States)

    Ukpai, S. N.; Okogbue, C. O.

    2017-11-01

    Until this study, the location and depth of the saline units in Uburu-Okposi salt lake areas and environs have been unknown. This study aimed at delineating the saline lithofacies and dispersal configurations to water bodies, using electrical geophysical methods such as constant separation traversing (CST) and vertical electrical sounding (VES). Results showed weathered zones that represent aquifers mostly at the fourth geoelectric layer: between upper layered aquitards and underlying aquitards at depths 30-140 m. Lateral distribution of resistivity variance was defined by the CST, whereas the VES tool, targeted at low-resistivity zones, detected isolated saline units with less than 10 ohm-m at depths generally >78 m. The saline lithofacies were suspected to link freshwater zones via shear zones, which steer saline water towards the salt lakes and influence the vulnerability of groundwater to salinization. The level of salinization was verified by water sampling and analysis, and results showed general alkaline water type with a mean pH of 7.66. Water pollution was indicated: mean total dissolved solids (TDS) 550 mg/l, electrical conductivity (EC) 510 μS/cm, salinity 1.1‰, Cl- 200 mg/l, N03 -35.5 mg/l, Na+ 19.6 mg/l and Ca2+ 79.3 mg/l. The salinity is controlled by NaCl salt, as deduced from correlation analysis using the software package Statistical Product for Service Solutions (SPSS). Generally, concentrations of dissolved ions in the water of the area are enhanced via mechanisms such as evaporation, dissociation of salts, precipitation run off and leaching of dissolved rock minerals.

  10. The Conterminous United States Mineral Assessment Program; background information to accompany folio of geologic, geochemical, geophysical, and mineral resource maps of the Ajo and Lukeville 1 degree x 2 degrees quadrangles, Arizona

    Science.gov (United States)

    Gray, Floyd; Tosdal, R.M.; Peterson, J.A.; Cox, D.P.; Miller, R.J.; Klein, D.P.; Theobald, P.K.; Haxel, G.B.; Grubensky, M.J.; Raines, G.L.; Barton, H.N.; Singer, D.A.; Eppinger, R.G.

    1992-01-01

    Encompassing about 21,000 km 2 in southwestern Arizona, the Ajo and Lukeville 1 ? by 2 ? quadrangles have been the subject of mineral resource investigations utilizing field and laboratory studies in the disciplines of geology, geochemistry, geophysics, and Landsat imagery. The results of these studies are published as a folio of maps, figures, and tables, with accompanying discussions. Past mineral production has been limited to copper from the Ajo Mining District. In addition to copper, the quadrangles contain potentially significant resources of gold and silver; a few other commodities, including molybdenum and evaporites, may also exist in the area as appreciable resources. This circular provides background information on the mineral deposits and on the investigations and integrates the information presented in the folio. The bibliography cites references to the geology, geochemistry, geophysics, and mineral deposits of the two quadrangles.

  11. An integrated geochemical, geophysical and mineralogical study of river sediments in alpine area and soil samples near steel plant, in Austria

    Science.gov (United States)

    Irfan, M. I.; Meisel, T.

    2012-04-01

    Concentration of nickel and chromium in any part of the ecosystem is important for environmental concerns in particular human health due to the reason that some species of them can cause health problem e.g. dermatitis and cancer. Sediment samples collected form a river Vordernberger Bach (Leoben, Austria) in an alpine region and soil samples collected in an area adjacent to steel production unit in same narrow valley were investigated. In previous studies a correlation between magnetic susceptibility values and concentration of nickel and chromium showed that a magnetic susceptibility meter can be used to point out the contaminated areas as in-situ device. The purpose of the whole study is to understand the real (point or diffuse, anthropogenic or geogenic) sources of contamination of soils, water and river sediments through heavy metal deposition. Unseparated, magnetic and non-magnetic fractions of soil samples were investigated for geochemical and mineralogical aspects with XRF, ICP-MS, EMPA, Multi-Functional Kappabridge (MFK1) and laser ablation coupled with ICP-MS. Mineralogical study of sediment samples for several sampling points with higher Ni and Cr content was performed. Sediment samples were sieved below 1.4 mm and then a concentrate of heavy minerals was prepared in the field through panning. Concentrated heavy minerals were then subjected for heavy liquid separation in the laboratory. Separated magnetic and non-magnetic fractions below 0.71/0.1 mm and density greater than 2.9 g/cm3 were selected for mineralogical investigation. The abundance of typical anthropogenic particles, e.g., spherical, tinder, roasted ores, iron and steel mill slag was observed under the microscope. Magnetite (mostly anthropogenic), maghemite, chromspinel, chromite (type I & II), (Ca,Al)-ferrite, wustite, apatite (anthropogenic), olivine mixed crystals, calcium silicate and spinel (anthropogenic) are found in magnetic fraction. Non-magnetic fractions contain hematite, siderite

  12. Geophysical Field Theory

    International Nuclear Information System (INIS)

    Eloranta, E.

    2003-11-01

    The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)

  13. geophysical and geochemical characterization of zango abattoir

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    chemical analysis of soil and water samples were conducted at ... The use of water is restrained by its quality which makes it unhealthy for a particular use, thus, water quality depends on the physical, chemical and biological composition of water. ... generated by military radio transmitters that use the VLF (Very.

  14. Exploration Geophysics

    Science.gov (United States)

    Savit, Carl H.

    1978-01-01

    Expansion of activity and confirmation of new technological directions characterized several fields of exploration geophysics in 1977. Advances in seismic-reflection exploration have been especially important. (Author/MA)

  15. Agricultural Geophysics

    Science.gov (United States)

    The four geophysical methods predominantly used for agricultural purposes are resistivity, electromagnetic induction, ground penetrating radar (GPR), and time domain reflectometry (TDR). Resistivity and electromagnetic induction methods are typically employed to map lateral variations of apparent so...

  16. Geophysical Investigations of the Uranium Mineralized Formation in the Coaly Black Shale Deposits in Korea

    Science.gov (United States)

    Kim, C.; Son, J.; Yoon, H.; Park, S.

    2011-12-01

    Geophysical investigations using electrical resistivity, Spectral Induced Polarization (SIP) methods, and laboratory measurements of the rock physical properties were conducted for uranium exploration in the Okchoen Metamorphic Belt in Korea. The geology of the study site consists of age-unknown slate formations such as coaly black and dark gray slates, limestone interbedded in the slates, and intrusion of cretaceous quartz porphyry of the acidic dikes. The slate formations shows the strike of N40~60E and dip 50~60 toward northwest direction in the site. It has been reported that the low grade concentration of uranium minerals were found in the coaly black slate formations in the site. The main objective of the study is to investigate the geological structures of the slate formations including uranium-bearing black slates. The resistivity of the dark gray slate was measured to be 1,800-10,000 Ohm-M, while that of the coaly black slate to be 17-200 Ohm-M. The conceptual geophysical model of the uranium-bearing black coal slates was constructed for geologic structure of the site, consisting of very high-angled formation with low resistivity and with high IP response due to the presences of coal and pyrite components. On the contrary, the dark gray slates show the geophysical properties of relatively high resistivity, and low IP response due to the absence of sulfide minerals. The results of the geophysical surveys showed high IP response was detected in the coal-bearing slate formation due to sulfide minerals such as pyrite. In addition, the low resistivity anomalies with very high angles were also detected due to coal component in the black slates on both numerical resistivity modeling using conceptual model and on the field resistivity data. The results of the geophysical investigation are in good agreement with the geological and geochemical study results, and were employed for drilling investigations in the site. In order to probe the uranium-bearing formation

  17. Geophysical Conceptual Model for Benthic Flux and Submarine Groundwater Discharge

    Science.gov (United States)

    King, J. N.

    2010-12-01

    Numerous investigators characterize benthic flux and submarine groundwater discharge (SGD) using a geochemical conceptual model that relies on the estimation of tracer fluxes into and out of a control volume. (Benthic flux is the rate of flow across the bed of any water body, per unit area of bed. Benthic flux is a vector that includes both discharge and recharge components. SGD is a benthic water discharge flux to a marine water body.) For the geochemical approach, benthic discharge flux or SGD is estimated by summing the flux of tracer into or out of the control volume---a water body or portion of a water body---and deducing that tracer deficiency within the control volume must be explained by SGD. Typically, estimated or measured fluxes include advection and mixing in surface-water, diffusion, evasion across the air-water interface, production, and decay. The geochemical model, however, does not account for fluxes that do not transport tracer. For example, investigators found equivalent (the upper 30 cm of sediment in the Indian River Lagoon, Florida, in June and July 2003. At this location, a surface-gravity wave with a five-centimeter amplitude and one-second period in 0.5 m of water forced a 12-cm-per-day SGD. The radon tracer technique may not characterize SGD forced by the one-second wave due to the time scale of the wave, the absence of a radon activity gradient between bed medium and surface water, and the the wave affects the flow field within the porous medium. A new geophysical conceptual model for benthic flux is proposed. The model parses benthic flux into components driven by individual forcing mechanisms. The model recognizes that benthic flux components may interact in a constructive or destructive manner, such that benthic flux generated by multiple forcing mechanisms at the same location may not be equivalent to the linear sum of benthic flux generated by single forcing mechanisms. Restated: the whole may be different than the sum of the parts

  18. Geophysics- and geochemistry-based assessment of the geochemical characteristics and groundwater-flow system of the U.S. part of the Mesilla Basin/Conejos-Médanos aquifer system in Doña Ana County, New Mexico, and El Paso County, Texas, 2010–12

    Science.gov (United States)

    Teeple, Andrew P.

    2017-06-16

    One of the largest rechargeable groundwater systems by total available volume in the Rio Grande/Río Bravo Basin (hereinafter referred to as the “Rio Grande”) region of the United States and Mexico, the Mesilla Basin/Conejos-Médanos aquifer system, supplies water for irrigation as well as for cities of El Paso, Texas; Las Cruces, New Mexico; and Ciudad Juárez, Chihuahua, Mexico. The U.S. Geological Survey in cooperation with the Bureau of Reclamation assessed the groundwater resources in the Mesilla Basin and surrounding areas in Doña Ana County, N. Mex., and El Paso County, Tex., by using a combination of geophysical and geochemical methods. The study area consists of approximately 1,400 square miles in Doña Ana County, N. Mex., and 100 square miles in El Paso County, Tex. The Mesilla Basin composes most of the study area and can be divided into three parts: the Mesilla Valley, the West Mesa, and the East Bench. The Mesilla Valley is the part of the Mesilla Basin that was incised by the Rio Grande between Selden Canyon to the north and by a narrow valley (about 4 miles wide) to the southeast near El Paso, Tex., named the Paso del Norte, which is sometimes referred to in the literature as the “El Paso Narrows.”Previously published geophysical data for the study area were compiled and these data were augmented by collecting additional geophysical and geochemical data. Geophysical resistivity measurements from previously published helicopter frequency domain electromagnetic data, previously published direct-current resistivity soundings, and newly collected (2012) time-domain electromagnetic soundings were used in the study to detect spatial changes in the electrical properties of the subsurface, which reflect changes that occur within the hydrogeology. The geochemistry of the groundwater system was evaluated by analyzing groundwater samples collected in November 2010 for physicochemical properties, major ions, trace elements, nutrients, pesticides

  19. Integrated Geohazard Screening Using Remote Sensing, Including Satellite and Helicopter Based Imagery, LiDAR, and Geophysics, in Tajikistan and Kyrgyzstan, Central Asia

    Science.gov (United States)

    Wade, A. M.; Kozaci, O.; Hitchcock, C. S.; Konieczny, G.; Garrie, D.

    2015-12-01

    We performed a detailed geohazard investigation of a 5 km-wide, 650km-long corridor through Tajikistan and Kyrgyzstan, Central Asia. The study area includes the Rasht and Alai valleys at the boundary between the Pamir Mountains and the Alai Range of the southern Tien Shan. Ongoing collision between the India and Eurasia plates has resulted in the Tien Shan orogenic belt and the Pamir Mountains. Thus the study area is one of the most seismically active regions in the world. Rapid uplift, erosion, and steep slopes give rise to widespread landsliding and massive rock slope failures in both the Pamir and Tien Shan Mountains. Our integrated data acquisition and interpretation plan used airborne and remote sensing methods including satellite based DEMs and high resolution imagery, LiDAR, aerial photography, and helicopter based electromagnetic resistivity (HEM). Analysis of these data sets allowed us to delineate potential geohazards through surficial geologic mapping. Initial desktop geohazard screening included 1:50,000-scale mapping for potential faults, landslides, and liquefiable deposits, which included traffic light-style susceptibility maps for route refinement and hazard mitigation. As part of detailed investigations, continuous HEM data was collected and processed at a spatial sampling interval of approximately 3m. Apparent resistivity was calculated for each of the five operating frequencies over the entire survey area. For the purposes of this study, resistivity values at 10 m and 20 m depths were sliced from the interpolated 3D Differential Resistivity model for use in the analysis. Using GIS, we compared these results with mapped Quaternary units and found good correlation between resistivity contrasts and the boundaries of mapped surficial units. With this confidence, the HEM measurements were further analyzed to identify subsurface features and to develop a 3D geologic model. Based on this analysis we provided a framework for an optimized geotechnical

  20. Geophysical characterization from Itu intrusive suite

    International Nuclear Information System (INIS)

    Pascholati, M.E.

    1989-01-01

    The integrated use of geophysical, geological, geochemical, petrographical and remote sensing data resulted in a substantial increase in the knowledge of the Itu Intrusive Suite. The main geophysical method was gamma-ray spectrometry together with fluorimetry and autoradiography. Three methods were used for calculation of laboratory gamma-ray spectrometry data. For U, the regression method was the best one. For K and Th, equations system and absolute calibration presented the best results. Surface gamma-ray spectrometry allowed comparison with laboratory data and permitted important contribution to the study of environmental radiation. (author)

  1. ANNALS OF GEOPHYSICS: AD MAJORA

    Directory of Open Access Journals (Sweden)

    Fabio Florindo

    2014-03-01

    Full Text Available Annals of Geophysics is a bimonthly international journal, which publishes scientific papers in the field of geophysics sensu lato. It derives from Annali di Geofisica, which commenced publication in January 1948 as a quarterly periodical devoted to general geophysics, seismology, earth magnetism, and atmospheric studies. The journal was published regularly for a quarter of a century until 1982 when it merged with the French journal Annales de Géophysique to become Annales Geophysicae under the aegis of the European Geophysical Society. In 1981, this journal ceased publication of the section on solid earth geophysics, ending the legacy of Annali di Geofisica. In 1993, the Istituto Nazionale di Geofisica (ING, founder of the journal, decided to resume publication of its own journal under the same name, Annali di Geofisica. To ensure continuity, the first volume of the new series was assigned the volume number XXXVI (following the last issue published in 1982. In 2002, with volume XLV, the name of the journal was translated into English to become Annals of Geophysics and in consequence the journal impact factor counter was restarted. Starting in 2010, in order to improve its status and better serve the science community, Annals of Geophysics has instituted a number of editorial changes including full electronic open access, freely accessible online, the possibility to comment on and discuss papers online, and a board of editors representing Asia and the Americas as well as Europe. [...

  2. Geophysical Monitoring of Hydrological and Biogeochemical Transformations associated with Cr(VI) Bioremediation

    International Nuclear Information System (INIS)

    Hubbard, Susan; Williams, Kenneth H.; Conrad, Mark E.; Faybishenko, Boris; Peterson, John; Chen, Jinsong; Long, Philip E.; Hazen, Terry C.

    2008-01-01

    Understanding how hydrological and biogeochemical properties change over space and time in response to remedial treatments is hindered by our ability to monitor these processes with sufficient resolution and over field relevant scales. Here, we explored the use of geophysical approaches for monitoring the spatiotemporal distribution of hydrological and biogeochemical transformations associated with a Cr(VI)bioremediation experiment performed at Hanford, WA. We first integrated hydrological wellbore and geophysical tomographic datasets to estimate hydrological zonation at the study site. Using results from laboratory biogeophysical experiments and constraints provided by field geochemical datasets, we then interpreted time-lapse seismic and radar tomographic datasets, collected during thirteen acquisition campaigns over a three year experimental period, in terms of hydrological and biogeochemical transformations. The geophysical monitoring datasets were used to infer: the spatial distribution of injected electron donor; the evolution of gas bubbles; variations in total dissolved solids (nitrate and sulfate) as a function of pumping activity; the formation of precipitates and dissolution of calcites; and concomitant changes in porosity. Although qualitative in nature, the integrated interpretation illustrates how geophysical techniques have the potential to provide a wealth of information about coupled hydrobiogeochemical responses to remedial treatments in high spatial resolution and in a minimally invasive manner. Particularly novel aspects of our study include the use of multiple lines of evidence to constrain the interpretation of a long-term, field-scale geophysical monitoring dataset and the interpretation of the transformations as a function of hydrological heterogeneity and pumping activity

  3. Petrographic and Geochemical Characterization of Ore-Bearing Intrusions of the Noril'sk type, Siberia; With Discussion of Their Origin, Including Additional Datasets and Core Logs

    Science.gov (United States)

    Czamanske, Gerald K.

    2002-01-01

    The Noril'sk I, Talnakh, and Kharaelakh intrusions of the Noril'sk district host one of the outstanding metal concentrations in the world; contained Cu-Ni resources are comparable to the deposits at Sudbury, Ontario and the platinum group element (PGE) resource is second only to that of the Bushveld Complex. Our opportunity to cooperatively sample and study this district in Siberian Russia arose in 1990 through a memorandum of understanding between the U.S. Geological Survey and the former Ministry of Geology of the U.S.S.R. The world-class significance of these deposits and the possibility that understanding their geologic context, including construction of a credible 'ore-deposit model,' will lead to discovery of similar deposits elsewhere, inspired extensive studies of the ores, the mafic-intrusions which host them, and associated flood basalts.

  4. Geophysical System Verification (GSV): A Physics-Based Alternative to Geophysical Prove-Outs for Munitions Response. Addendum

    Science.gov (United States)

    2015-09-24

    FINAL REPORT Geophysical System Verification (GSV): A Physics-Based Alternative to Geophysical Prove-Outs for Munitions Response July 2009...NUMBER (Include area code) 15-07-2009 Final Report July 2009 GEOPHYSICAL SYSTEM VERIFICATION (GSV): A PHYSICS-BASED ALTERNATIVE TO GEOPHYSICAL PROVE-OUTS...Arlington, Virginia 22203 SERDP/ESTCP N/A Unlimited distribution This document highlights a more rigorous physics-based alternative to geophysical

  5. Geophysical System Verification (GSV): A Physics-Based Alternative to Geophysical Prove-Outs for Munitions Response

    Science.gov (United States)

    2015-09-24

    FINAL REPORT Geophysical System Verification (GSV): A Physics-Based Alternative to Geophysical Prove-Outs for Munitions Response July 2009...NUMBER (Include area code) 15-07-2009 Final Report July 2009 GEOPHYSICAL SYSTEM VERIFICATION (GSV): A PHYSICS-BASED ALTERNATIVE TO GEOPHYSICAL PROVE-OUTS...Arlington, Virginia 22203 SERDP/ESTCP N/A Unlimited distribution This document highlights a more rigorous physics-based alternative to geophysical

  6. Geochemical Arrays at Woolsey Mound Seafloor Observatory

    Science.gov (United States)

    Sleeper, K.; Wilson, R. M.; Chanton, J.; Lapham, L.; Farr, N.; Camilli, R.; Martens, C. S.; Pontbriand, C.

    2011-12-01

    incorporated into the Benthic Boundary Layer Array for high-speed, wireless data transmission. Combining this system with a cabled observatory will allow real-time monitoring of gas hydrates in the natural environment. The arrays have each been deployed at the Woolsey Mound Seafloor Observatory for extended durations. Woolsey Mound is at a depth of approximately 900m on the continental slope of the northern Gulf of Mexico in Mississippi Canyon Federal Lease Block 118. The Observatory is a multi-component facility that will have geophysical and microbial components in addition to the geochemical arrays described here. The goal of the Observatory is to develop a facility to evaluate the formation and stability of gas hydrates in a natural system. Specific areas of interest include geohazards, alternative energy resources, climate change and unique, deep- marine habitats. The poster presents the major geochemical arrays at Woolsey Mound Seafloor Observatory, including their design, sensor specifications, deployment and installation platforms, and scientific relevance.

  7. Sustainable urban development and geophysics

    Science.gov (United States)

    Liu, Lanbo; Chan, L. S.

    2007-09-01

    The new millennium has seen a fresh wave of world economic development especially in the Asian-Pacific region. This has contributed to further rapid urban expansion, creating shortages of energy and resources, degradation of the environment, and changes to climatic patterns. Large-scale, new urbanization is mostly seen in developing countries but urban sprawl is also a major social problem for developed nations. Urbanization has been accelerating at a tremendous rate. According to data collected by the United Nations [1], 50 years ago less than 30% of the world population lived in cities. Now, more than 50% are living in urban settings which occupy only about 1% of the Earth's surface. During the period from 1950 to 1995, the number of cities with a population higher than one million increased from 83 to 325. By 2025 it is estimated that more than 60% of 8.3 billion people (the projected world population [1]) will be city dwellers. Urbanization and urban sprawl can affect our living quality both positively and negatively. In recent years geophysics has found significant and new applications in highly urbanized settings. Such applications are conducive to the understanding of the changes and impacts on the physical environment and play a role in developing sustainable urban infrastructure systems. We would like to refer to this field of study as 'urban geophysics'. Urban geophysics is not simply the application of geophysical exploration in the cities. Urbanization has brought about major changes to the geophysical fields of cities, including those associated with electricity, magnetism, electromagnetism and heat. An example is the increased use of electromagnetic waves in wireless communication, transportation, office automation, and computer equipment. How such an increased intensity of electromagnetic radiation affects the behaviour of charged particles in the atmosphere, the equilibrium of ecological systems, or human health, are new research frontiers to be

  8. Major results of geophysical investigations at Yucca Mountain and vicinity, southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, H.W.; Ponce, D.A. [eds.] [Geological Survey, Menlo Park, CA (United States); Hunter, W.C. [ed.] [Geological Survey, Denver, CO (United States). Yucca Mountain Project Branch

    1995-12-31

    In the consideration of Yucca Mountain as a possible site for storing high level nuclear waste, a number of geologic concerns have been suggested for study by the National Academy of Sciences which include: (1) natural geologic and geochemical barriers, (2) possible future fluctuations in the water table that might flood a mined underground repository, (3) tectonic stability, and (4) considerations of shaking such as might be caused by nearby earthquakes or possible volcanic eruptions. This volume represents the third part of an overall plan of geophysical investigation of Yucca Mountain, preceded by the Site Characterization Plan (SCP; dated 1988) and the report referred to as the Geophysical White Paper, Phase 1, entitled Status of Data, Major Results, and Plans for Geophysical Activities, Yucca Mountain Project (Oliver and others, 1990). The SCP necessarily contained uncertainty about applicability and accuracy of methods then untried in the Yucca Mountain volcano-tectonic setting, and the White Paper, Phase 1, focused on summarization of survey coverage, data quality, and applicability of results. For the most part, it did not present data or interpretation. The important distinction of the current volume lies in presentation of data, results, and interpretations of selected geophysical methods used in characterization activities at Yucca Mountain. Chapters are included on the following: gravity investigations; magnetic investigations; regional magnetotelluric investigations; seismic refraction investigations; seismic reflection investigations; teleseismic investigations; regional thermal setting; stress measurements; and integration of methods and conclusions. 8 refs., 60 figs., 2 tabs.

  9. Major results of geophysical investigations at Yucca Mountain and vicinity, southern Nevada

    International Nuclear Information System (INIS)

    Oliver, H.W.; Ponce, D.A.; Hunter, W.C.

    1995-01-01

    In the consideration of Yucca Mountain as a possible site for storing high level nuclear waste, a number of geologic concerns have been suggested for study by the National Academy of Sciences which include: (1) natural geologic and geochemical barriers, (2) possible future fluctuations in the water table that might flood a mined underground repository, (3) tectonic stability, and (4) considerations of shaking such as might be caused by nearby earthquakes or possible volcanic eruptions. This volume represents the third part of an overall plan of geophysical investigation of Yucca Mountain, preceded by the Site Characterization Plan (SCP; dated 1988) and the report referred to as the Geophysical White Paper, Phase 1, entitled Status of Data, Major Results, and Plans for Geophysical Activities, Yucca Mountain Project (Oliver and others, 1990). The SCP necessarily contained uncertainty about applicability and accuracy of methods then untried in the Yucca Mountain volcano-tectonic setting, and the White Paper, Phase 1, focused on summarization of survey coverage, data quality, and applicability of results. For the most part, it did not present data or interpretation. The important distinction of the current volume lies in presentation of data, results, and interpretations of selected geophysical methods used in characterization activities at Yucca Mountain. Chapters are included on the following: gravity investigations; magnetic investigations; regional magnetotelluric investigations; seismic refraction investigations; seismic reflection investigations; teleseismic investigations; regional thermal setting; stress measurements; and integration of methods and conclusions. 8 refs., 60 figs., 2 tabs

  10. 77 FR 19321 - Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf (OCS)

    Science.gov (United States)

    2012-03-30

    ... Bureau of Ocean Energy Management Geological and Geophysical Exploration on the Atlantic Outer... environmental effects of multiple Geological and Geophysical (G&G) activities in the Mid- and South Atlantic...-sonar surveys, electromagnetic surveys, geological and geochemical sampling, and remote sensing. The...

  11. Released geophysical and geological reports : Newfoundland offshore area September 2003

    International Nuclear Information System (INIS)

    2003-09-01

    This two-part publication contains a list of geophysical and geological data acquired by the Canada-Newfoundland Offshore Petroleum Board (C-NOPB). It is made available to the public in accordance with a subsection of the Canada-Newfoundland Atlantic Accord Implementation Act which states that such data can be released five years after the date of completion of a program. The programs for which the data has been released are listed in chronological order by completion date. A list of wells drilled within the C-NOPB's jurisdictional area is also included along with a map showing the area of jurisdiction. The well data includes category 1 information from exploratory wells, delineation wells, and development wells. It includes factual data obtained directly from well drilling which must be made available for public examination 2 years after well completion. Category 1 data refers to drill cuttings, well fluid samples, open-hole logs, formation stimulation data, petroleum analyses, drill mud reports, and well site survey information. The interpretive geological and geophysical reports are based on industry data from exploratory programs conducted in the Newfoundland offshore area. They include information from synthetic seismograms, velocity surveys, vertical seismic profiles, petrological reports, geochemical reports, and cyberlook logs. The jurisdictional areas include Western Newfoundland, South Grand Banks, North Grand Banks, the Northeast Newfoundland Shelf, and the Labrador Shelf. Program numbers are coded to contain the geographic region to which the program relates, the type of proposed geophysical or geological work, the company operating the program, and the sequential number of that type of program operated by each company. 8 tabs

  12. The 'glass earth' - geochemical frontiers in exploration through cover

    International Nuclear Information System (INIS)

    Carr, G.; Denton, G.; Giblin, A.; Korsch, M.; Andrew, A.; Whitford, D.

    1999-01-01

    'Glass Earth' represents a number of current and planned projects within CSIRO aimed at making 'transparent' the top 1000 m of the Earth's crust It builds upon current technologies developed within a number of CSIRO divisions as well as the Australian Mineral Exploration Technologies CRC (AMET CRC), the Australian Geodynamics CRC (AG CRC) and the CRC for Landscape Evolution and Mineral Exploration (CRC LEME). New geophysical and geochemical technologies will be developed to complement these, together with new capabilities in modelling, data integration and visualisation, including hydrogeochemistry, hydrogeology, surface geochemistry and isotope geochemistry, modelling of chemical, fluid and heat flows in rock and regolith, advanced visualisation and data fusion. This paper describes some recent work in the field of isotope geochemistry, with the principal aim of 'seeing through' cover to understand basement geology and detect hidden ore systems

  13. Rapid geophysical surveyor

    International Nuclear Information System (INIS)

    Roybal, L.G.; Carpenter, G.S.; Josten, N.E.

    1993-01-01

    The Rapid Geophysical Surveyor (RGS) is a system designed to rapidly and economically collect closely-spaced geophysical data used for characterization of Department of Energy (DOE) waste sites. Geophysical surveys of waste sites are an important first step in the remediation and closure of these sites; especially older sties where historical records are inaccurate and survey benchmarks have changed due to refinements in coordinate controls and datum changes. Closely-spaced data are required to adequately differentiate pits, trenches, and soil vault rows whose edges may be only a few feet from each other. A prototype vehicle designed to collect magnetic field data was built at the Idaho national Engineering Laboratory (INEL) during the summer of 1992. The RGS was one of several projects funded by the Buried Waste Integrated Demonstration (BWID) program. This vehicle was demonstrated at the Subsurface Disposal Area (SDA) within the Radioactive Waste Management Complex (RWMC) on the INEL in September of 1992. Magnetic data were collected over two areas in the SDA, with a total survey area of about 1.7 acres. Data were collected at a nominal density of 2 1/2 inches along survey lines spaced 1 foot apart. Over 350,000 data points were collected over a 6 day period corresponding to about 185 man-days using conventional ground survey techniques. This report documents the design and demonstration of the RGS concept including the presentation of magnetic data collected at the SDA. The surveys were able to show pit and trench boundaries and determine details of their spatial orientation never before achieved

  14. The geochemical atlas of Alaska, 2016

    Science.gov (United States)

    Lee, Gregory K.; Yager, Douglas B.; Mauk, Jeffrey L.; Granitto, Matthew; Denning, Paul; Wang, Bronwen; Werdon, Melanie B.

    2016-06-21

    A rich legacy of geochemical data produced since the early 1960s covers the great expanse of Alaska; careful treatment of such data may provide significant and revealing geochemical maps that may be used for landscape geochemistry, mineral resource exploration, and geoenvironmental investigations over large areas. To maximize the spatial density and extent of data coverage for statewide mapping of element distributions, we compiled and integrated analyses of more than 175,000 sediment and soil samples from three major, separate sources: the U.S. Geological Survey, the National Uranium Resource Evaluation program, and the Alaska Division of Geological & Geophysical Surveys geochemical databases. Various types of heterogeneity and deficiencies in these data presented major challenges to our development of coherently integrated datasets for modeling and mapping of element distributions. Researchers from many different organizations and disparate scientific studies collected samples that were analyzed using highly variable methods throughout a time period of more than 50 years, during which many changes in analytical techniques were developed and applied. Despite these challenges, the U.S. Geological Survey has produced a new systematically integrated compilation of sediment and soil geochemical data with an average sample site density of approximately 1 locality per 10 square kilometers (km2) for the entire State of Alaska, although density varies considerably among different areas. From that compilation, we have modeled and mapped the distributions of 68 elements, thus creating an updated geochemical atlas for the State.

  15. Geochemical assessment of light gaseous hydrocarbons in near ...

    Indian Academy of Sciences (India)

    Light hydrocarbons in soil have been used as direct indicators in geochemical hydrocarbon exploration, which remains an unconventional path in the petroleum industry. The occurrence of adsorbed soil ... Kalpana1 D J Patil1 A M Dayal1. National Geophysical Research Institute, Uppal Road, Hyderabad 500606, India.

  16. National Geological and Geophysical Data Preservation Program: Successes and Lessons Learned

    Science.gov (United States)

    Adrian, B. M.

    2014-12-01

    The United States Geological Survey (USGS) is widely recognized in the earth science community as possessing extensive collections of geologic and geophysical materials gathered by its research personnel. Since the USGS was established in 1879, hundreds of thousands of samples have been gathered in collections that range from localized, geographically-based assemblages to ones that are national or international in scope. These materials include, but are not limited to, rock and mineral specimens; fossils; drill cores and cuttings; geochemical standards; and soil, sediment, and geochemical samples. The USGS National Geological and Geophysical Data Preservation Program (NGGDPP) was established with the passage of the Energy Policy Act of 2005. Since its implementation, the USGS NGGDPP has taken an active role in providing opportunities to inventory, archive and preserve geologic and geophysical samples, and to make these samples and ancillary data discoverable on the Internet. Preserving endangered geoscience collections is more cost effective than recollecting this information. Preserving these collections, however, is only one part of the process - there also needs to be a means to facilitate open discovery and access to the physical objects and the ancillary digital records. The NGGDPP has celebrated successes such as the development of the USGS Geologic Collections Management System (GCMS), a master catalog and collections management plan, and the implementation and advancement of the National Digital Catalog, a digital inventory and catalog of geological and geophysical data and collections held by the USGS and State geological surveys. Over this period of time there has been many lessons learned. With the successes and lessons learned, NGGDPP is poised to take on challenges the future may bring.

  17. Responsibilities, opportunities and challenges in geophysical exploration

    International Nuclear Information System (INIS)

    Rytle, R.J.

    1982-01-01

    Geophysical exploration for engineering purposes is conducted to decrease the risk in encountering site uncertainties in construction of underground facilities. Current responsibilities, opportunities and challenges for those with geophysical expertise are defined. These include: replacing the squiggly line format, developing verification sites for method evaluations, applying knowledge engineering and assuming responsibility for crucial national problems involving rock mechanics expertise

  18. Geochemical computer codes. A review

    International Nuclear Information System (INIS)

    Andersson, K.

    1987-01-01

    In this report a review of available codes is performed and some code intercomparisons are also discussed. The number of codes treating natural waters (groundwater, lake water, sea water) is large. Most geochemical computer codes treat equilibrium conditions, although some codes with kinetic capability are available. A geochemical equilibrium model consists of a computer code, solving a set of equations by some numerical method and a data base, consisting of thermodynamic data required for the calculations. There are some codes which treat coupled geochemical and transport modeling. Some of these codes solve the equilibrium and transport equations simultaneously while other solve the equations separately from each other. The coupled codes require a large computer capacity and have thus as yet limited use. Three code intercomparisons have been found in literature. It may be concluded that there are many codes available for geochemical calculations but most of them require a user that us quite familiar with the code. The user also has to know the geochemical system in order to judge the reliability of the results. A high quality data base is necessary to obtain a reliable result. The best results may be expected for the major species of natural waters. For more complicated problems, including trace elements, precipitation/dissolution, adsorption, etc., the results seem to be less reliable. (With 44 refs.) (author)

  19. Advances in geophysics

    CERN Document Server

    Sato, Haruo

    2013-01-01

    The critically acclaimed serialized review journal for over 50 years, Advances in Geophysics is a highly respected publication in the field of geophysics. Since 1952, each volume has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now in its 54th volume, it contains much material still relevant today--truly an essential publication for researchers in all fields of geophysics.Key features: * Contributions from leading authorities * Informs and updates on all the latest developments in the field

  20. Waterberg coalfield airborne geophysics

    CSIR Research Space (South Africa)

    Fourie, S

    2009-07-01

    Full Text Available Airborne Geophysics Project Number: 1.5.5 Sub Committee: Geology and Geophysics Presenter: Dr. Stoffel Fourie Co-Workers: Dr. George Henry & Me. Leonie Marè Collaborators: Coaltech & CSIR Project Objectives Major Objectives: circle5 Initiate Semi...-Regional Exploration of the Waterberg Coalfield to the benefit of the Industry. circle5 Generate a good quality Airborne Geophysical Dataset. circle5 Generate a basic lineament and surface geology interpretation of the Ellisras Basin. circle5 Generate a basic...

  1. Proceedings of the workshop on geochemical modeling

    International Nuclear Information System (INIS)

    1986-01-01

    The following collection of papers was presented at a workshop on geochemical modeling that was sponsored by the Office of Civilian Radioactive Waste Management Program at the Lawrence Livermore National Laboratory (LLNL). The LLNL Waste Management Program sponsored this conference based on their belief that geochemical modeling is particularly important to the radioactive waste disposal project because of the need to predict the consequences of long-term water-rock interactions at the proposed repository site. The papers included in this volume represent a subset of the papers presented at the Fallen Leaf Lake Conference and cover a broad spectrum of detail and breadth in a subject that reflects the diverse research interests of the conference participants. These papers provide an insightful look into the current status of geochemical modeling and illustrate how various geochemical modeling codes have been applied to problems of geochemical interest. The emphasis of these papers includes traditional geochemical modeling studies of individual geochemical systems, the mathematical and theoretical development and refinement of new modeling capabilities, and enhancements of data bases on which the computations are based. The papers in this proceedings volume have been organized into the following four areas: Geochemical Model Development, Hydrothermal and Geothermal Systems, Sedimentary and Low Temperature Environments, and Data Base Development. The participants of this symposium and a complete list of the talks presented are listed in the appendices

  2. 36 CFR 902.59 - Geological and geophysical information.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical information. 902.59 Section 902.59 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT... Geological and geophysical information. Any geological or geophysical information and data (including maps...

  3. Numerical studies in geophysics

    Science.gov (United States)

    Hier Majumder, Catherine Anne

    2003-10-01

    This thesis focuses on the use of modern numerical techniques in the geo- and environmental sciences. Four topics are discussed in this thesis: finite Prandtl number convection, wavelet analysis, inverse methods and data assimilation, and nuclear waste tank mixing. The finite Prandtl number convection studies examine how convection behavior changes as Prandtl numbers are increased to as high as 2 x 104, on the order of Prandtl numbers expected in very hot magmas or mushy ice diapirs. I found that there are significant differences in the convection style between finite Prandtl number convection and the infinite Prandtl number approximation even for Prandtl numbers on the order of 104. This indicates that the infinite Prandtl convection approximation might not accurately model behavior in fluids with large, but finite Prandtl numbers. The section on inverse methods and data assimilation used the technique of four dimensional variational data assimilation (4D-VAR) developed by meteorologists to integrate observations into forecasts. It was useful in studying the predictability and dependence on initial conditions of finite Prandtl simulations. This technique promises to be useful in a wide range of geological and geophysical fields, including mantle convection, hydrogeology, and sedimentology. Wavelet analysis was used to help image and scrutinize at small-scales both temperature and vorticity fields from convection simulations and the geoid. It was found to be extremely helpful in both cases. It allowed us to separate the information in the data into various spatial scales without losing the locations of the signals in space. This proved to be essential in understanding the processes producing the total signal in the datasets. The nuclear waste study showed that techniques developed in geology and geophysics can be used to solve scientific problems in other fields. I applied state-of-the-art techniques currently employed in geochemistry, sedimentology, and mantle

  4. Serious games for Geophysics

    Science.gov (United States)

    Lombardo, Valerio; Rubbia, Giuliana

    2015-04-01

    Childhood stage is indispensable in the education of human beings and especially critical to arise scientific interest in children. We discuss the participatory design of a didactic videogame, i.e. a "serious" game to teach geophysics and Earth sciences to high and low-school students. Geophysics is the application of the laws and techniques of physics to uncover knowledge about the earth's dynamic processes and subsurface structure. It explores phenomena such as earthquakes, volcanoes, tsunamis to improve our understanding of the earth's physical processes and our ability to predict reoccurrences. Effective mitigation of risks from catastrophic geologic hazards requires knowledge and understanding of local geology and geologic processes. Scientific outreach can be defined as discourse activity, whose main objective is to communicate some knowledge previously produced in scientific contexts to a non-expert massive audience. One of the difficulties science educators need to overcome is to explain specific concepts from a given discipline in a language simple and understandable for their audience. Digital games today play a large role in young people's lives. Games are directly connected to the life of today's adolescents. Therefore, digital games should be included and broached as a subject in the classroom. The ardor and enthusiasm that digital games evoke in teenagers has indeed brought many researchers, school leaders and teachers to the question "how video games" can be used to engage young people and support their learning inside the classroom. Additionally, studies have shown that digital games can enhance various skills such as the ability to concentrate, stamina, tactical aptness, anticipatory thinking, orientation in virtual spaces, and deductive reasoning. Thus, videogames become an effective didactic mechanism and should have a place in the classroom. The project aims to explore the potentials of entertainment technologies in educational processes

  5. Autonomous cloud based site monitoring through hydro geophysical data assimilation, processing and result delivery

    Science.gov (United States)

    Versteeg, R.; Johnson, D. V.; Rodzianko, A.; Zhou, H.; Dafflon, B.; Leger, E.; de Kleine, M.

    2017-12-01

    Understanding of processes in the shallow subsurface requires that geophysical, biogeochemical, hydrological and remote sensing datasets are assimilated, processed and interpreted. Multiple enabling software capabilities for process understanding have been developed by the science community. These include information models (ODM2), reactive transport modeling (PFLOTRAN, Modflow, CLM, Landlab), geophysical inversion (E4D, BERT), parameter estimation (PEST, DAKOTA), visualization (ViSiT, Paraview, D3, QGIS) as well as numerous tools written in python and R for petrophysical mapping, stochastic modeling, data analysis and so on. These capabilities use data collected using sensors and analytical tools developed by multiple manufacturers which produce many different measurements. While scientists obviously leverage tools, capabilities and lessons learned from one site at other sites, the current approach to site characterization and monitoring is very labor intensive and does not scale well. Our objective is to be able to monitor many (hundreds - thousands) of sites. This requires that monitoring can be done in a near time, affordable, auditable and essentially autonomous manner. For this we have developed a modular vertically integrated cloud based software framework which was designed from the ground up for effective site and process monitoring. This software framework (PAF - Predictive Assimilation Framework) is multitenant software and provides automation of data ingestion, processing and visualization of hydrological, geochemical and geophysical (ERT/DTS) data. The core organizational element of PAF is a project/user one in which capabilities available to users are controlled by a combination of available data and access permissions. All PAF capabilities are exposed through APIs, making it easy to quickly add new components. PAF is fully integrated with newly developed autonomous electrical geophysical hardware and thus allows for automation of electrical

  6. The Environmental Geophysics Web Site and Geophysical Decision Support System (GDSS)

    Science.gov (United States)

    This product provides assistance to project managers, remedial project managers, stakeholders, and anyone interested in on-site investigations or environmental geophysics. The APM is the beta version of the new U.S. EPA Environmental Geophysics Web Site which includes the Geophys...

  7. Geochemical exploration for uranium

    International Nuclear Information System (INIS)

    1988-01-01

    This Technical Report is designed mainly to introduce the methods and techniques of uranium geochemical exploration to exploration geologists who may not have had experience with geochemical exploration methods in their uranium programmes. The methods presented have been widely used in the uranium exploration industry for more than two decades. The intention has not been to produce an exhaustive, detailed manual, although detailed instructions are given for a field and laboratory data recording scheme and a satisfactory analytical method for the geochemical determination of uranium. Rather, the intention has been to introduce the concepts and methods of uranium exploration geochemistry in sufficient detail to guide the user in their effective use. Readers are advised to consult general references on geochemical exploration to increase their understanding of geochemical techniques for uranium

  8. Proceedings of 2. Brazilian Geochemical Congress

    International Nuclear Information System (INIS)

    1989-01-01

    Some works about geochemistry are presented, including themes about geochemical exploration, lithogeochemistry and isotope geochemistry, environmental geochemistry, analytical geochemistry, geochemistry of carbonatites and rare earth elements and organic geochemistry. (C.G.C.) [pt

  9. Faculty receives Excellence in Geophysical Education Award

    Science.gov (United States)

    Kruse, Sarah; Baldridge, W. Scott; Biehler, Shawn; Braile, Lawrence W.; Ferguson, John F.; Gilpin, Bernard E.; Jiracek, George R.

    “The second AGU Excellence in Geophysical Education Award was presented to the faculty of the Summer of Applied Geophysical Experience (SAGE): Scott Baldridge, Shawn Biehler, Larry Braile, John Ferguson, Bernard Gilpin, and George Jiracek. The persistence and commitment of this group has provided the geophysical community with a superb educational program for over 16 years, reaching nearly 400 students, including undergraduates, graduates, and professionals. The award was presented at the AGU Fall Meeting Honors Ceremony, which was held on December 8, 1998, in San Francisco, California.

  10. SAGE (Summer of Applied Geophysical Experience): Learning Geophysics by Doing Geophysics

    Science.gov (United States)

    Jiracek, G. R.; Baldridge, W. S.; Biehler, S.; Braile, L. W.; Ferguson, J. F.; Gilpin, B. E.; Pellerin, L.

    2005-12-01

    SAGE, a field-based educational program in applied geophysical methods has been an REU site for 16 years and completed its 23rd year of operation in July 2005. SAGE teaches the major geophysical exploration methods (including seismics, gravity, magnetics, and electromagnetics) and applies them to the solution of specific local and regional geologic problems. These include delineating buried hazardous material; mapping archaeological sites; and studying the structure, tectonics, and water resources of the Rio Grande rift in New Mexico. Nearly 600 graduates, undergraduates, and professionals have attended SAGE since 1983. Since 1990 REU students have numbered 219 coming from dozens of different campuses. There have been 124 underrepresented REU students including 100 women, 14 Hispanics, 7 Native Americans, and 3 African Americans. Tracking of former REU students has revealed that 81% have gone on to graduate school. Keys to the success of SAGE are hands-on immersion in geophysics for one month and a partnership between academia, industry, and a federal laboratory. Successful approaches at SAGE include: 1) application of the latest equipment by all students; 2) continued updating of equipment, computers, and software by organizing universities and industry affiliates; 3) close ties with industry who provide supplemental instruction, furnish new equipment and software, and alert students to the current industry trends and job opportunities; 4) two-team, student data analysis structure that simultaneously addresses specific geophysical techniques and their integration; and 5) oral and written reports patterned after professional meetings and journals. An eight member, 'blue ribbon' advisory panel from academia, industry, and the federal government has been set up to maintain the vitality of SAGE by addressing such issues as funding, new faculty, organization, and vision. SAGE is open to students from any university (or organization) with backgrounds including

  11. Review of geophysical characterization methods used at the Hanford Site

    International Nuclear Information System (INIS)

    GV Last; DG Horton

    2000-01-01

    This paper presents a review of geophysical methods used at Hanford in two parts: (1) shallow surface-based geophysical methods and (2) borehole geophysical methods. This review was not intended to be ''all encompassing'' but should represent the vast majority (>90% complete) of geophysical work conducted onsite and aimed at hazardous waste investigations in the vadose zone and/or uppermost groundwater aquifers. This review did not cover geophysical methods aimed at large-scale geologic structures or seismicity and, in particular, did not include those efforts conducted in support of the Basalt Waste Isolation Program. This review focused primarily on the more recent efforts

  12. Review of geophysical characterization methods used at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    GV Last; DG Horton

    2000-03-23

    This paper presents a review of geophysical methods used at Hanford in two parts: (1) shallow surface-based geophysical methods and (2) borehole geophysical methods. This review was not intended to be ``all encompassing'' but should represent the vast majority (>90% complete) of geophysical work conducted onsite and aimed at hazardous waste investigations in the vadose zone and/or uppermost groundwater aquifers. This review did not cover geophysical methods aimed at large-scale geologic structures or seismicity and, in particular, did not include those efforts conducted in support of the Basalt Waste Isolation Program. This review focused primarily on the more recent efforts.

  13. Radioactivity and geophysics

    International Nuclear Information System (INIS)

    Radvanyi, P.

    1992-01-01

    The paper recalls a few steps of the introduction of radioactivity in geophysics and astrophysics: contribution of radioelements to energy balance of the Earth, age of the Earth based on radioactive disintegration and the discovery of cosmic radiations

  14. Geophysical Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Geophysical Research Facility (GRF) is a 60 ft long × 22 ft wide × 7 ft deep concrete basin at CRREL for fresh or saltwater investigations and can be temperature...

  15. Geophysical borehole logging

    International Nuclear Information System (INIS)

    McCann, D.; Barton, K.J.; Hearn, K.

    1981-08-01

    Most of the available literature on geophysical borehole logging refers to studies carried out in sedimentary rocks. It is only in recent years that any great interest has been shown in geophysical logging in boreholes in metamorphic and igneous rocks following the development of research programmes associated with geothermal energy and nuclear waste disposal. This report is concerned with the programme of geophysical logging carried out on the three deep boreholes at Altnabreac, Caithness, to examine the effectiveness of these methods in crystalline rock. Of particular importance is the assessment of the performance of the various geophysical sondes run in the boreholes in relation to the rock mass properties. The geophysical data can be used to provide additional in-situ information on the geological, hydrogeological and engineering properties of the rock mass. Fracturing and weathering in the rock mass have a considerable effect on both the design parameters for an engineering structure and the flow of water through the rock mass; hence, the relation between the geophysical properties and the degree of fracturing and weathering is examined in some detail. (author)

  16. A ''model'' geophysics program

    International Nuclear Information System (INIS)

    Nyquist, J.E.

    1994-01-01

    In 1993, I tested a radio-controlled airplane designed by Jim Walker of Brigham Young University for low-elevation aerial photography. Model-air photography retains most of the advantages of standard aerial photography --- the photographs can be used to detect lineaments, to map roads and buildings, and to construct stereo pairs to measure topography --- and it is far less expensive. Proven applications on the Oak Ridge Reservation include: updating older aerial records to document new construction; using repeated overflights of the same area to capture seasonal changes in vegetation and the effects of major storms; and detecting waste trench boundaries from the color and character of the overlying grass. Aerial photography is only one of many possible applications of radio-controlled aircraft. Currently, I am funded by the Department of Energy's Office of Technology Development to review the state of the art in microavionics, both military and civilian, to determine ways this emerging technology can be used for environmental site characterization. Being particularly interested in geophysical applications, I am also collaborating with electrical engineers at Oak Ridge National Laboratory to design a model plane that will carry a 3-component flux-gate magnetometer and a global positioning system, which I hope to test in the spring of 1994

  17. Karoo airborne geophysical survey

    International Nuclear Information System (INIS)

    Cole, D.J.; Stettler, E.H.

    1984-01-01

    Thirty four uranium anomalies were selected for ground follow-up from the analogue spectrometer records of Block 4 of the Karoo Airborne Geophysical Survey. The anomalies were plotted on 1:50 000 scale topographic maps and to 1:250 000 scale maps which are included in this report. The anomaly co-ordinates are tabulated together with the farms on which they occur. Results of the ground follow-up of the aerial anomalies are described. Twenty two anomalies are related to uranium mineralisation of which seventeen occur over baked mudstone adjacent to a dolerite intrusion. Five are located over fluvial channel sandstone of the Beaufort Group and subsurface mineralised sandstone may be present. The other twelve anomalies are spurious. Of the anomalies located over baked mudstone, fifteen emanate from ferruginous mudstone of the Whitehill Formation west of longitude 21 degrees 15 minutes. One of the two remaining anomalies over baked mudstone occurs over the Prince Albert Formation and the other anomaly is over baked mudstone and calcareous nodules of the Beaufort Group. The general low uranium values (less than 355 ppm eU3O8) render the occurrences uneconomic

  18. The National Geochemical Survey; database and documentation

    Science.gov (United States)

    ,

    2004-01-01

    The USGS, in collaboration with other federal and state government agencies, industry, and academia, is conducting the National Geochemical Survey (NGS) to produce a body of geochemical data for the United States based primarily on stream sediments, analyzed using a consistent set of methods. These data will compose a complete, national-scale geochemical coverage of the US, and will enable construction of geochemical maps, refine estimates of baseline concentrations of chemical elements in the sampled media, and provide context for a wide variety of studies in the geological and environmental sciences. The goal of the NGS is to analyze at least one stream-sediment sample in every 289 km2 area by a single set of analytical methods across the entire nation, with other solid sample media substituted where necessary. The NGS incorporates geochemical data from a variety of sources, including existing analyses in USGS databases, reanalyses of samples in USGS archives, and analyses of newly collected samples. At the present time, the NGS includes data covering ~71% of the land area of the US, including samples in all 50 states. This version of the online report provides complete access to NGS data, describes the history of the project, the methodology used, and presents preliminary geochemical maps for all analyzed elements. Future editions of this and other related reports will include the results of analysis of variance studies, as well as interpretive products related to the NGS data.

  19. Introduction to the JEEG Agricultural Geophysics Special Issue

    Science.gov (United States)

    Allred, Barry J.; Smith, Bruce D.

    2010-01-01

    Near-surface geophysical methods have become increasingly important tools in applied agricultural practices and studies. The great advantage of geophysical methods is their potential rapidity, low cost, and spatial continuity when compared to more traditional methods of assessing agricultural land, such as sample collection and laboratory analysis. Agricultural geophysics investigations commonly focus on obtaining information within the soil profile, which generally does not extend much beyond 2 meters beneath the ground surface. Although the depth of interest oftentimes is rather shallow, the area covered by an agricultural geophysics survey can vary widely in scale, from experimental plots (10 s to 100 s of square meters), to farm fields (10 s to 100 s of hectares), up to the size of watersheds (10 s to 100 s of square kilometers). To date, three predominant methods—resistivity, electromagnetic induction (EMI), and ground-penetrating radar (GPR)—have been used to obtain surface-based geophysical measurements within agricultural settings. However, a recent conference on agricultural geophysics (Bouyoucos Conference on Agricultural Geophysics, September 8–10, 2009, Albuquerque, New Mexico; www.ag-geophysics.org) illustrated that other geophysical methods are being applied or developed. These include airborne electromagnetic induction, magnetometry, seismic, and self-potential methods. Agricultural geophysical studies are also being linked to ground water studies that utilize deeper penetrating geophysical methods than normally used.

  20. Evaluation of uranium geochemical anomalies in the Charlotte 10 x 20 NTMS quadrangle

    International Nuclear Information System (INIS)

    Carpenter, R.H.

    1981-11-01

    This report contains a synthesis of published geological, geophysical, and geochemical information for portions of Cabarrus and Rowan Counties, NC, where uranium geochemical anomalies have been described by Heffner and Ferguson (1978). The results of a ground radiation survey in selected areas are also described. Based on an evaluation of published information and the data obtained in the field study, conclusions are made regarding the possible occurrence of uranium concentration. Recommendations for detailed surveys in certain areas are also presented

  1. Application of multiple geochemical indicators, including the stable isotopes of water, to differentiate water quality evolution in a region influenced by various agricultural practices and domestic wastewater treatment and disposal

    International Nuclear Information System (INIS)

    Butler, Thomas W.

    2007-01-01

    Spatial and temporal variations in groundwater chemistry indicate that the use of low TDS lake water for irrigation, on land located just south of the City of Dixon, Solano County, California, is primarily responsible for improving groundwater quality with regards to salts. The stable isotopes of water further support this finding and suggest that TDS concentrations decrease as groundwater evolves to a more highly evaporated state. This seemingly contradictory finding was primarily attributed to infiltration of low TDS Lake Berryessa surface water, which has an isotopic signature indicative of an evaporated source and is used extensively for irrigation in the area, mixing with poorer quality locally recharged shallow groundwater. Geochemical modeling using the program PHREEQC further supports the anthropogenic aquifer freshening hypotheses through computed reductions in the saturation state of carbonate minerals in the vicinity of land irrigated by lake derived water, which is undersaturated with regards to modeled carbonates. Additionally, δ 18 O and δ 2 H were found to be useful in estimating climatic variables such as temperature and humidity, illustrating the potential for applying these models in hydrologic investigations within the area. It was however found that USDA NRCS soils data and measured water chemistry were not well correlated and thus the use of soils classifications to assess potential groundwater quality impacts was of limited utility

  2. Proceedings of 13. International Geochemical Exploration Symposium. 2. Brazilian Geochemical Congress

    International Nuclear Information System (INIS)

    1989-01-01

    Some works about geochemistry are presented, including themes about geochemical exploration, lithogeochemistry and isotope geochemistry, environmental geochemistry, analyical geochemistry, geochemistry of carbonatites and rare earth elements and organic geochemistry. (C.G.C.) [pt

  3. Methods for geochemical analysis

    Science.gov (United States)

    Baedecker, Philip A.

    1987-01-01

    The laboratories for analytical chemistry within the Geologic Division of the U.S. Geological Survey are administered by the Office of Mineral Resources. The laboratory analysts provide analytical support to those programs of the Geologic Division that require chemical information and conduct basic research in analytical and geochemical areas vital to the furtherance of Division program goals. Laboratories for research and geochemical analysis are maintained at the three major centers in Reston, Virginia, Denver, Colorado, and Menlo Park, California. The Division has an expertise in a broad spectrum of analytical techniques, and the analytical research is designed to advance the state of the art of existing techniques and to develop new methods of analysis in response to special problems in geochemical analysis. The geochemical research and analytical results are applied to the solution of fundamental geochemical problems relating to the origin of mineral deposits and fossil fuels, as well as to studies relating to the distribution of elements in varied geologic systems, the mechanisms by which they are transported, and their impact on the environment.

  4. Inverse problems of geophysics

    International Nuclear Information System (INIS)

    Yanovskaya, T.B.

    2003-07-01

    This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

  5. Device for geophysical exploration

    Directory of Open Access Journals (Sweden)

    Ergashev S.F.

    2017-03-01

    Full Text Available In the article a device is offered for geophysical secret service, resulted block chart and temporal diagrams. It is experimentally set, the use of detonation generators allowed to use more high-frequency harmonic constituents of echo-signals for determination of object on a depth a to 100 m.

  6. Geochemical Investigations of Groundwater Stability

    Energy Technology Data Exchange (ETDEWEB)

    Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

    2006-05-15

    The report describes geochemical parameters and methods that provide information about the hydrodynamic stability of groundwaters in low permeability fractured rocks that are potential hosts for radioactive waste repositories. Hydrodynamic stability describes the propensity for changes in groundwater flows over long timescales, in terms of flow rates and flow directions. Hydrodynamic changes may also cause changes in water compositions, but the related issue of geochemical stability of a potential repository host rock system is outside the scope of this report. The main approaches to assessing groundwater stability are numerical modelling, measurement and interpretation of geochemical indicators in groundwater compositions, and analyses and interpretations of secondary minerals and fluid inclusions in these minerals. This report covers the latter two topics, with emphasis on geochemical indicators. The extent to which palaeohydrogeology and geochemical stability indicators have been used in past safety cases is reviewed. It has been very variable, both in terms of the scenarios considered, the stability indicators considered and the extent to which the information was explicitly or implicitly used in assessing FEPs and scenarios in the safety cases. Geochemical indicators of hydrodynamic stability provide various categories of information that are of hydrogeological relevance. Information about groundwater mixing, flows and water sources is potentially provided by the total salinity of groundwaters, their contents of specific non-reactive solutes (principally chloride) and possibly of other solutes, the stable isotopic ratio of water, and certain characteristics of secondary minerals and fluid inclusions. Information pertaining directly to groundwater ages and the timing of water and solute movements is provided by isotopic systems including tritium, carbon-14, chlorine-36, stable oxygen and hydrogen isotopes, uranium isotopes and dissolved mobile gases in

  7. Geochemical prospecting in Guiana

    International Nuclear Information System (INIS)

    Coulomb, R.

    1957-01-01

    During the last few years geochemical prospecting techniques have become common usage in the field of mineral deposit prospecting. The real scope of these methods lies in their use in the prospecting of large areas. The most promising use of the geochemistry and hydro-geochemistry of uranium is in heavily forested tropical territories, with few outcrops, where radiometry is strongly handicapped. (author) [fr

  8. Reconnaissance Geochemical Study

    African Journals Online (AJOL)

    Geochemical exploration of Orle district within the Igarra schist belt in southwestern Nigeria was carried out using reconnaissance ... The occurrence of pathfinder elements such as As and W; and of rock units, such as amphibolites and pegmatites, within the schist belt that ...... house for national prosperity. Inaugural.

  9. Geophysical investigations in Jordan

    Science.gov (United States)

    Kovach, R.L.; Andreasen, G.E.; Gettings, M.E.; El-Kaysi, K.

    1990-01-01

    A number of geophysical investigations have been undertaken in the Hashemite Kingdom of Jordan to provide data for understanding the tectonic framework, the pattern of seismicity, earthquake hazards and geothermal resources of the country. Both the historical seismic record and the observed recent seismicity point to the dominance of the Dead Sea Rift as the main locus of seismic activity but significant branching trends and gaps in the seismicity pattern are also seen. A wide variety of focal plane solutions are observed emphasizing the complex pattern of fault activity in the vicinity of the rift zone. Geophysical investigations directed towards the geothermal assessment of the prominent thermal springs of Zerga Ma'in and Zara are not supportive of the presence of a crustal magmatic source. ?? 1990.

  10. Geophysical investigations of the Romuvaara area, Finland

    International Nuclear Information System (INIS)

    Saksa, P.; Paananen, M.

    1991-06-01

    In the study area of Romuvaara, investigations have been carried out during 1987 - 90 with the aim of finding out whether the polyphasically deformed Precambrian gneiss complex is suitable for the final disposal of spent nuclear fuel. The bedrock has been studied by geological, geophysical, geohydrological and geochemical methods. Airborne, ground and borehole geophysical surveys were used in studying the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre. Airborne surveys (magnetic, radiometric and two electromagnetic methods) and ground surveys (VLF and VLF-R, magnetic and soil radar methods) were useful in distinguishing the metadiabases, amphibolites and granodiorites from the less magnetized migmatites. The electromagnetic and seismic refraction surveys were used in locating crushed and fractured zones. The rock type distribution was studied by single-hole logging of susceptibility, natural γ radiation and radiometric γ-γ -density. Electrical and acoustic logging served the mapping of fractures and the interpretation of water injection tests. The flow conditions in the boreholes were studied by fluid logging and tube-wave sounding. The rock volume surrounding the boreholes was mapped by borehole radar with a frequency of 22 MHz. The upper parts of the boreholes were also studied by vertical radar profiling (VRP). Larger volumes of rock were mapped by vertical seismic profiling (VSP) using 4 - 5 transmitter shotholes per borehole

  11. Rapid Geophysical Surveyor

    International Nuclear Information System (INIS)

    Roybal, L.G.; Carpenter, G.S.; Josten, N.E.

    1993-01-01

    The Rapid Geophysical Surveyor (RGS) is a system designed to rapidly and economically collect closely-spaced geophysical data used for characterization of US Department of Energy waste sites. Geophysical surveys of waste sites are an important first step in the remediation and closure of these sites; especially older sites where historical records are inaccurate and survey benchmarks have changed because of refinements in coordinate controls and datum changes. Closely-spaced data are required to adequately differentiate pits, trenches, and soil vault rows whose edges may be only a few feet from each other. A prototype vehicle designed to collect magnetic field data was built at the Idaho National Engineering Laboratory (INEL) during the summer of 1992. The RGS was funded by the Buried Waste Integrated Demonstration program. This vehicle was demonstrated at the Subsurface Disposal Area (SDA) within the Radioactive Waste Management Complex at the INEL in September 1992. Magnetic data were collected over two areas in the SDA, with a total survey area of about 1.7 acres. Data were collected at a nominal density of 2 1/2 in. along survey lines spaced 1-ft apart. Over 350,000 data points were collected over a 6 day period corresponding to about 185 worker-days using conventional ground survey techniques

  12. Application of fractal content-gradient method for delineating geochemical anomalies associated with copper occurrences in the Yangla ore field, China

    Directory of Open Access Journals (Sweden)

    Zhen Chen

    2017-01-01

    Full Text Available Fractal and multi-fractal content area method finds application in a wide variety of geological, geochemical and geophysical fields. In this study, the fractal content-gradient method was used on 1:10,000 scale to delineate geochemical anomalies associated with copper mineralization. Analysis of geochemical data from the Yangla super large Cu-Pb-Zn polymetallic ore district using the fractal content-gradient method, combined with other geological data from this area, indicates that ore-prospecting in the ore district should focus on Cu as the main metal and Pb-Zn and Au as the auxiliary metals. The types of deposits include (in chronological order re-formed sedimentary exhalative (SEDEX, skarns, porphyries, and hydrothermal vein-type deposits. Three ore-prospecting targets are divided on a S–N basis: (1 the Qulong exploration area, in which the targets are porphyry-type Cu deposits; (2 the Zongya exploration area, where the targets are porphyry-type Cu and hydrothermal vein-type Cu-Pb polymetallic deposits; and (3 the Zarelongma exploration area, characterized mainly skarn-type “Yangla-style” massive sulfide Cu-Pb deposits. Our study demonstrates that the fractal content-gradient method is convenient, simple, rapid, and direct for delineating geochemical anomalies and for outlining potential exploration targets.

  13. Alaska Geochemical Database (AGDB)-Geochemical data for rock, sediment, soil, mineral, and concentrate sample media

    Science.gov (United States)

    Granitto, Matthew; Bailey, Elizabeth A.; Schmidt, Jeanine M.; Shew, Nora B.; Gamble, Bruce M.; Labay, Keith A.

    2011-01-01

    The Alaska Geochemical Database (AGDB) was created and designed to compile and integrate geochemical data from Alaska in order to facilitate geologic mapping, petrologic studies, mineral resource assessments, definition of geochemical baseline values and statistics, environmental impact assessments, and studies in medical geology. This Microsoft Access database serves as a data archive in support of present and future Alaskan geologic and geochemical projects, and contains data tables describing historical and new quantitative and qualitative geochemical analyses. The analytical results were determined by 85 laboratory and field analytical methods on 264,095 rock, sediment, soil, mineral and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed in USGS laboratories or, under contracts, in commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects from 1962 to 2009. In addition, mineralogical data from 18,138 nonmagnetic heavy mineral concentrate samples are included in this database. The AGDB includes historical geochemical data originally archived in the USGS Rock Analysis Storage System (RASS) database, used from the mid-1960s through the late 1980s and the USGS PLUTO database used from the mid-1970s through the mid-1990s. All of these data are currently maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB were used to generate most of the AGDB data set. These data were checked for accuracy regarding sample location, sample media type, and analytical methods used. This arduous process of reviewing, verifying and, where necessary, editing all USGS geochemical data resulted in a significantly improved Alaska geochemical dataset. USGS data that were not previously in the NGDB because the data predate the earliest USGS geochemical databases, or were once excluded for programmatic reasons

  14. Merging information in geophysics: the triumvirat of geology, geophysics, and petrophysics

    Science.gov (United States)

    Revil, A.

    2016-12-01

    We know that geophysical inversion is non-unique and that many classical regularization techniques are unphysical. Despite this, we like to use them because of their simplicity and because geophysicists are often afraid to bias the inverse problem by introducing too much prior information (in a broad sense). It is also clear that geophysics is done on geological objects that are not random structures. Spending some time with a geologist in the field, before organizing a field geophysical campaign, is always an instructive experience. Finally, the measured properties are connected to physicochemical and textural parameters of the porous media and the interfaces between the various phases of a porous body. .Some fundamental parameters may control the geophysical observtions or their time variations. If we want to improve our geophysical tomograms, we need to be risk-takers and acknowledge, or rather embrqce, the cross-fertilization arising by coupling geology, geophysics, and ptrophysics. In this presentation, I will discuss various techniques to do so. They will include non-stationary geostatistical descriptors, facies deformation, cross-coupled petrophysical properties using petrophysical clustering, and image-guided inversion. I will show various applications to a number of relevant cases in hydrogeophysics. From these applications, it may become clear that there are many ways to address inverse or time-lapse inverse problems and geophysicists have to be pragmatic regarding the methods used depending on the degree of available prior information.

  15. Geochemical modeling: a review

    International Nuclear Information System (INIS)

    Jenne, E.A.

    1981-06-01

    Two general families of geochemical models presently exist. The ion speciation-solubility group of geochemical models contain submodels to first calculate a distribution of aqueous species and to secondly test the hypothesis that the water is near equilibrium with particular solid phases. These models may or may not calculate the adsorption of dissolved constituents and simulate the dissolution and precipitation (mass transfer) of solid phases. Another family of geochemical models, the reaction path models, simulates the stepwise precipitation of solid phases as a result of reacting specified amounts of water and rock. Reaction path models first perform an aqueous speciation of the dissolved constituents of the water, test solubility hypotheses, then perform the reaction path modeling. Certain improvements in the present versions of these models would enhance their value and usefulness to applications in nuclear-waste isolation, etc. Mass-transfer calculations of limited extent are certainly within the capabilities of state-of-the-art models. However, the reaction path models require an expansion of their thermodynamic data bases and systematic validation before they are generally accepted

  16. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1979-01-01

    The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which I and my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same ti...

  17. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1982-01-01

    The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which land my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same tim...

  18. Image processing of airborne geophysical data: a potential exploration tool for atomic minerals

    International Nuclear Information System (INIS)

    Shanti Kumar, C.; Bhairam, C.L.; Kak, S.N.; Achar, K.K.

    1993-01-01

    Data sets obtained from airborne gamma-ray spectrometric (AGRS) and aeromagnetic (AM) surveys, after necessary correction, are usually presented as profiles or as contour maps for interpretation in mineral exploration and geological analysis. Currently, imaging of the geophysical data sets have been extensively used as they have many advantages in their usage compared to conventional techniques. For the application of image processing techniques to the AGRS and AM data, software programs were customized for converting the digital data compatible to the satellite image processing system (SIPS). The geophysical data has been imaged and rectified to a poly conic projection, using cubic convolution resampling technique. While imaging, the radioelemental concentration values are rescaled to 256 grey levels. Software for the statistical information of radioelements and printing of coloured paper image have also been developed. Some of the image processing techniques used include, generation of colour composite images for preparing radioelemental (eU,eTh, and K) images and radioelemental colour composite images (K,eTh, eU) enabling display of a combined radioelemental distribution. Aeromagnetic data on the other hand are displayed in grey tone, pseudo-colours, and shaded relief images. Many other image enhancement techniques used for improving the display for further interpretation comprise, band ratioing, band combinations, filtering, look up table manipulation, and other similar functions. Advanced image processing techniques such as the principal component analysis (PCA) for understanding the geochemical and geological phenomena and the hue saturation and intensity (HSI) transformation for integration of radioelemental data with its corresponding satellite images facilitated display of radioelemental images draped over the satellite image. Statistics of radioelement and inter-elemental relationship has been obtained. The paper deals with the methodology adopted in the

  19. Geochemical modelling baseline compositions of groundwater

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Kjøller, Claus; Andersen, Martin Søgaard

    2008-01-01

    dissolution (East Midlands, Valreas and Aveiro). Reactive transport models, employing the code PHREEQC, which included these geochemical processes and one-dimensional solute transport were able to duplicate the observed patterns in water quality. These models may provide a quantitative understanding...

  20. Hydrogeological-Geophysical Methods for Subsurface Site Characterization - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, Yoram

    2001-01-01

    The goal of this research project is to increase water savings and show better ecological control of natural vegetation by developing hydrogeological-geophysical methods for characterizing the permeability and content of water in soil. The ground penetrating radar (GPR) tool was developed and used as the surface geophysical method for monitoring water content. Initial results using the tool suggest that surface GPR is a viable technique for obtaining precision volumetric water content profile estimates, and that laboratory-derived petrophysical relationships could be applied to field-scale GPR data. A field-scale bacterial transport study was conducted within an uncontaminated sandy Pleistocene aquifer to evaluate the importance of heterogeneity in controlling the transport of bacteria. Geochemical, hydrological, geological, and geophysical data were collected to characterize the site prior to and after chemical and bacterial injection experiments. Study results shows that, even within the fairly uniform shallow marine deposits of the narrow channel focus area, heterogeneity existed that influenced the chemical tracer transport over lateral distances of a few meters and vertical distances of less than a half meter. The interpretation of data suggest that the incorporation of geophysical data with limited hydrological data may provide valuable information about the stratigraphy, log conductivity values, and the spatial correlation structure of log conductivity, which have traditionally been obtainable only by performing extensive and intrusive hydrological sampling.

  1. Geophysical Research Abstracts. Volume 10

    International Nuclear Information System (INIS)

    2008-01-01

    The EGU general assembly 2008 brought together geoscientists and space and planetary scientists from all over Europe and the rest of the world into one meeting covering all disciplines of the earth and planetary sciences: geology, geomorphology, geochemistry, geophysics, geobiology and hazards research as well as planetary and space sciences. Its scientific program included oral and poster sessions on disciplinary and interdisciplinary topics such as atmospheric sciences; climate: past, present, future; energy; resources and the environment; isotopes in geosciences: instrumentation and data systems; magnetism, palaeomagnetism, rock physics and geomaterials; ocean sciences; soil system sciences and solar-terrestrial sciences among others. Those presentations which belong to the subject scope of INIS database are indexed separately. (nevyjel)

  2. Fractals in geology and geophysics

    Science.gov (United States)

    Turcotte, Donald L.

    1989-01-01

    The definition of a fractal distribution is that the number of objects N with a characteristic size greater than r scales with the relation N of about r exp -D. The frequency-size distributions for islands, earthquakes, fragments, ore deposits, and oil fields often satisfy this relation. This application illustrates a fundamental aspect of fractal distributions, scale invariance. The requirement of an object to define a scale in photograhs of many geological features is one indication of the wide applicability of scale invariance to geological problems; scale invariance can lead to fractal clustering. Geophysical spectra can also be related to fractals; these are self-affine fractals rather than self-similar fractals. Examples include the earth's topography and geoid.

  3. Geophysics on Wikipedia

    Science.gov (United States)

    Newell, A. J.

    2010-12-01

    A priority for both NSF and AGU is the communication of scientific knowledge to the public. One way of determining where the public is looking for information is to search for geophysical terms on Google. Often the first hit is a Wikipedia site. Wikipedia is often the first place that high school students look. Yet there are few geophysicists who contribute to Wikipedia pages. This is particularly true of paleomagnetism and related subjects. In this project, efforts to improve the extent and quality of paleomagnetism coverage are described. The state of the Wikipedia articles at the beginning of this project is compared with their current state. The process of organizing the large number of articles and prioritizing them is described, along with ways to form collaborations on Wikipedia between geophysicists.

  4. Geophysics of Mars

    Science.gov (United States)

    Wells, R. A.

    1979-01-01

    A physical model of Mars is presented on the basis of light-scattering observations of the Martian atmosphere and surface and interior data obtained from observations of the geopotential field. A general description of the atmosphere is presented, with attention given to the circulation and the various cloud types, and data and questions on the blue haze-clearing effect and the seasonal darkening wave are summarized and the Mie scattering model developed to explain these observations is presented. The appearance of the planet from earth and spacecraft through Mariner 9 is considered, and attention is given to the preparation of topographical contour maps, the canal problem and large-scale lineaments observed from Mariner 9, the gravity field and shape of the planet and the application of Runcorn's geoid/convection theory to Mars. Finally, a summary of Viking results is presented and their application to the understanding of Martian geophysics is discussed.

  5. Sampling functions for geophysics

    Science.gov (United States)

    Giacaglia, G. E. O.; Lunquist, C. A.

    1972-01-01

    A set of spherical sampling functions is defined such that they are related to spherical-harmonic functions in the same way that the sampling functions of information theory are related to sine and cosine functions. An orderly distribution of (N + 1) squared sampling points on a sphere is given, for which the (N + 1) squared spherical sampling functions span the same linear manifold as do the spherical-harmonic functions through degree N. The transformations between the spherical sampling functions and the spherical-harmonic functions are given by recurrence relations. The spherical sampling functions of two arguments are extended to three arguments and to nonspherical reference surfaces. Typical applications of this formalism to geophysical topics are sketched.

  6. Developments in geophysical exploration methods

    CERN Document Server

    1982-01-01

    One of the themes in current geophysical development is the bringing together of the results of observations made on the surface and those made in the subsurface. Several benefits result from this association. The detailed geological knowledge obtained in the subsurface can be extrapolated for short distances with more confidence when the geologi­ cal detail has been related to well-integrated subsurface and surface geophysical data. This is of value when assessing the characteristics of a partially developed petroleum reservoir. Interpretation of geophysical data is generally improved by the experience of seeing the surface and subsurface geophysical expression of a known geological configuration. On the theoretical side, the understanding of the geophysical processes themselves is furthered by the study of the phenomena in depth. As an example, the study of the progress of seismic wave trains downwards and upwards within the earth has proved most instructive. This set of original papers deals with some of ...

  7. Physical and chemical characteristics including total and geochemical forms of phosphorus in sediment from the top 30 centimeters of cores collected in October 2006 at 26 sites in Upper Klamath Lake, Oregon

    Science.gov (United States)

    Simon, Nancy S.; Ingle, Sarah N.

    2011-01-01

    μThis study of phosphorus (P) cycling in eutrophic Upper Klamath Lake (UKL), Oregon, was conducted by the U.S. Geological Survey in cooperation with the U.S. Bureau of Reclamation. Lakebed sediments from the upper 30 centimeters (cm) of cores collected from 26 sites were characterized. Cores were sampled at 0.5, 1.5, 2.5, 3.5, 4.5, 10, 15, 20, 25, and 30 cm. Prior to freezing, water content and sediment pH were determined. After being freeze-dried, all samples were separated into greater than 63-micron (μm) particle-size (coarse) and less than 63-μm particle-size (fine) fractions. In the surface samples (0.5 to 4.5 cm below the sediment water interface), approximately three-fourths of the particles were larger than 63-μm. The ratios of the coarse particle-size fraction (>63 μm) and the fine particle-size fraction (determination of total concentrations of aluminum (Al), calcium (Ca), carbon (C), iron (Fe), poorly crystalline Fe, nitrogen (N), P, and titanium (Ti). Total Fe concentrations were the largest in sediment from the northern portion of UKL, Howard Bay, and the southern portion of the lake. Concentrations of total Al, Ca, and Ti were largest in sediment from the northern, central, and southernmost portions of the lake and in sediment from Howard Bay. Concentrations of total C and N were largest in sediment from the embayments and in sediment from the northern arm and southern portion of the lake in the general region of Buck Island. Concentrations of total C were larger in the greater than 63-μm particle-size fraction than in the less than 63-μm particle-size fraction. Sediments were sequentially extracted to determine concentrations of inorganic forms of P, including loosely sorbed P, P associated with poorly crystalline Fe oxides, and P associated with mineral phases. The difference between the concentration of total P and sum of the concentrations of inorganic forms of P is referred to as residual P. Residual P was the largest fraction of P in all

  8. Application of cluster analysis to geochemical compositional data for identifying ore-related geochemical anomalies

    Science.gov (United States)

    Zhou, Shuguang; Zhou, Kefa; Wang, Jinlin; Yang, Genfang; Wang, Shanshan

    2017-12-01

    Cluster analysis is a well-known technique that is used to analyze various types of data. In this study, cluster analysis is applied to geochemical data that describe 1444 stream sediment samples collected in northwestern Xinjiang with a sample spacing of approximately 2 km. Three algorithms (the hierarchical, k-means, and fuzzy c-means algorithms) and six data transformation methods (the z-score standardization, ZST; the logarithmic transformation, LT; the additive log-ratio transformation, ALT; the centered log-ratio transformation, CLT; the isometric log-ratio transformation, ILT; and no transformation, NT) are compared in terms of their effects on the cluster analysis of the geochemical compositional data. The study shows that, on the one hand, the ZST does not affect the results of column- or variable-based (R-type) cluster analysis, whereas the other methods, including the LT, the ALT, and the CLT, have substantial effects on the results. On the other hand, the results of the row- or observation-based (Q-type) cluster analysis obtained from the geochemical data after applying NT and the ZST are relatively poor. However, we derive some improved results from the geochemical data after applying the CLT, the ILT, the LT, and the ALT. Moreover, the k-means and fuzzy c-means clustering algorithms are more reliable than the hierarchical algorithm when they are used to cluster the geochemical data. We apply cluster analysis to the geochemical data to explore for Au deposits within the study area, and we obtain a good correlation between the results retrieved by combining the CLT or the ILT with the k-means or fuzzy c-means algorithms and the potential zones of Au mineralization. Therefore, we suggest that the combination of the CLT or the ILT with the k-means or fuzzy c-means algorithms is an effective tool to identify potential zones of mineralization from geochemical data.

  9. Geochemical Survey of Pernambuco

    International Nuclear Information System (INIS)

    Horowitz, A.; Duarte, P.J.; Almeida, M.G. de; Medeiros, M.O.

    1988-01-01

    The area studied i this work is located in a triangle formed by the Sibiro and Boca da Mata Sugar-Mills and Serinhaem country. In the Cabo Formation the search determinated conglomerates, arcos and clays. Although the highest geochemical activity have been done in the decomposed crystalin, and the values from Cabo Formation don't be encourager, this formation has lithology compatible with uranium mineralization. The Cabo Formation's sediments presents lithologic variations very expressives, with conglomerates, arcoses and clay silts, which determinate the choise of the area. This area presented favorable to uranium prospecting and to others elements interesting to ragional geochemistry. The atomic absorption analysis, fluorimetry and spectrometry were done for the following elements: Zn, V, Ti, Ni, Pb, Mn, Ga, Cu, Co, Bi, Ag, B, Mo, and U. (C.D.G.) [pt

  10. GEOPHYSICAL PROPERTIES OF SOILS

    KAUST Repository

    Santamarina, Carlos

    2016-12-01

    Low energy perturbations used in geophysical methods provide insightful information about constant-fabric soil properties and their spatial variability. There are causal links between soil type, index properties, elastic wave velocity, electromagnetic wave parameters and thermal properties. Soil type relates to the stress-dependent S-wave velocity, thermal and electrical conductivity and permittivity. The small strain stiffness reflects the state of stress, the extent of diagenetic cementation and/or freezing. Pore fluid chemistry, fluid phase and changes in either fluid chemistry or phase manifest through electromagnetic measurements. The volumetric water content measured with electromagnetic techniques is the best predictor of porosity if the water saturation is 100%. Changes in water saturation alter the P-wave velocity when Srà100%, the S-wave velocity at intermediate saturations, and the thermal conductivity when the saturation is low Srà0%. Finally, tabulated values suffice to estimate heat capacity and latent heat for engineering design, however thermal conductivity requires measurements under proper field conditions.

  11. A review of nuclear geophysics

    International Nuclear Information System (INIS)

    Clayton, C.G.; Schweitzer, J.S.

    1992-01-01

    This paper summarizes the development of nuclear geophysics in scientific and technological content and in range from its beginnings early in this century to the present day. We note that the early work in nuclear geophysics was originally referred to under the umbrella of open-quotes isotope applicationsclose quotes and the origin of the term open-quotes nuclear geophysicsclose quotes (which is seen to clarify and to focus work in this area) is exposed in this paper. The current expansion of nuclear geophysics front its original concern with oil well logging is an important trend because much of the underlying science, technology, and instrumentation is common ground. A review of nuclear geophysics would be a barren document without reference to long-term and, in some cases, short-term commercial and economic as well as to technological considerations, since these factors are the principal motivation for further development

  12. The geology and geophysics of the Oslo rift

    Science.gov (United States)

    Ruder, M. E.

    1981-01-01

    The regional geology and geophysical characteristics of the Oslo graben are reviewed. The graben is part of a Permian age failed continental rift. Alkali olivine, tholefitic, and monzonitic intrusives as well as basaltic lavas outline the extent of the graben. Geophysical evidence indicates that rifting activity covered a much greater area in Skagerrak Sea as well as the Paleozoic time, possibly including the northern Skagerrak Sea as well as the Oslo graben itself. Much of the surficial geologic characteristics in the southern part of the rift have since been eroded or covered by sedimentation. Geophysical data reveal a gravity maximum along the strike of the Oslo graben, local emplacements of magnetic material throughout the Skagerrak and the graben, and a slight mantle upward beneath the rift zone. Petrologic and geophysical maps which depict regional structure are included in the text. An extensive bibliography of pertinent literature published in English between 1960 and 1980 is also provided.

  13. Planetary Geophysics and Tectonics

    Science.gov (United States)

    Zuber, Maria

    2005-01-01

    The broad objective of this work is to improve understanding of the internal structures and thermal and stress histories of the solid planets by combining results from analytical and computational modeling, and geophysical data analysis of gravity, topography and tectonic surface structures. During the past year we performed two quite independent studies in the attempt to explain the Mariner 10 magnetic observations of Mercury. In the first we revisited the possibility of crustal remanence by studying the conditions under which one could break symmetry inherent in Runcorn's model of a uniformly magnetized shell to produce a remanent signal with a dipolar form. In the second we applied a thin shell dynamo model to evaluate the range of intensity/structure for which such a planetary configuration can produce a dipole field consistent with Mariner 10 results. In the next full proposal cycle we will: (1) develop numerical and analytical and models of thin shell dynamos to address the possible nature of Mercury s present-day magnetic field and the demise of Mars magnetic field; (2) study the effect of degree-1 mantle convection on a core dynamo as relevant to the early magnetic field of Mars; (3) develop models of how the deep mantles of terrestrial planets are perturbed by large impacts and address the consequences for mantle evolution; (4) study the structure, compensation, state of stress, and viscous relaxation of lunar basins, and address implications for the Moon s state of stress and thermal history by modeling and gravity/topography analysis; and (5) use a three-dimensional viscous relaxation model for a planet with generalized vertical viscosity distribution to study the degree-two components of the Moon's topography and gravity fields to constrain the primordial stress state and spatial heterogeneity of the crust and mantle.

  14. A >100 Ma Mantle Geochemical Record: Retiring Mantle Plumes may be Premature

    Science.gov (United States)

    Konter, J. G.; Hanan, B. B.; Blichert-Toft, J.; Koppers, A. A.; Plank, T.; Staudigel, H.

    2006-12-01

    Hotspot volcanism has long been attributed to mantle plumes, but in recent years suggestions have been made that plate tectonic processes, such as extension, can account for all hotspot tracks. This explanation involves a profoundly less dynamic lower mantle, which justifies a critical evaluation before the plume model is dismissed. Such an evaluation has to involve a wide range of geochemical, geological, and geophysical techniques, broadly investigating the products of volcanism as well as the underlying lithosphere and mantle. We argue here that the combined geological record and geochemistry of intraplate volcanoes holds some important clues that help us decide between models of plume-like upwelling versus passive upwelling with lithospheric extension. The best of these integrated datasets can be obtained from the long seamount chains in the Pacific Ocean. A new combined dataset of trace element and isotopic compositions, along with modern 40Ar/39Ar ages from seamounts in the Gilbert Ridge, Tokelau chain, and West Pacific Seamount Province (WPSP) provides a record of current to Cretaceous volcanism in the South Pacific. We have reconstructed the eruptive locations of the seamounts using a range of absolute plate motion models, including some models with hotspot motion and others that use the Indo-Atlantic hotspot reference frame. Our results show that the backtracked locations consistently form clusters (300km radius) around the active ends of the Macdonald, Rurutu and Rarotonga hotspot chains, while closely matching their distinct C-HIMU and C-EM1 signatures. The oldest WPSP seamounts (older than 100 Ma) form the only exception and backtrack, with larger uncertainty, to north of Rarotonga. Therefore, the mantle currently underlying the Cook-Austral islands has produced volcanoes in three geochemically distinct areas for at least 100 m.y. Furthermore, we find the shortest mantle residence time, 0.6 Ga, for a source of mixed recycled DMM and an EM1-like

  15. COTHERM: Geophysical Modeling of High Enthalpy Geothermal Systems

    Science.gov (United States)

    Grab, Melchior; Maurer, Hansruedi; Greenhalgh, Stewart

    2014-05-01

    In recent years geothermal heating and electricity generation have become an attractive alternative energy resource, especially natural high enthalpy geothermal systems such as in Iceland. However, the financial risk of installing and operating geothermal power plants is still high and more needs to be known about the geothermal processes and state of the reservoir in the subsurface. A powerful tool for probing the underground system structure is provided by geophysical techniques, which are able to detect flow paths and fracture systems without drilling. It has been amply demonstrated that small-scale features can be well imaged at shallow depths, but only gross structures can be delineated for depths of several kilometers, where most high enthalpy systems are located. Therefore a major goal of our study is to improve geophysical mapping strategies by multi-method geophysical simulations and synthetic data inversions, to better resolve structures at greater depth, characterize the reservoir and monitor any changes within it. The investigation forms part of project COTHERM - COmbined hydrological, geochemical and geophysical modeling of geoTHERMal systems - in which a holistic and synergistic approach is being adopted to achieve multidisciplinary cooperation and mutual benefit. The geophysical simulations are being performed in combination with hydrothermal fluid flow modeling and chemical fluid rock interaction modeling, to provide realistic constraints on lithology, pressure, temperature and fluid conditions of the subsurface. Two sites in Iceland have been selected for the study, Krafla and Reykjanes. As a starting point for the geophysical modeling, we seek to establish petrophysical relations, connecting rock properties and reservoir conditions with geophysical parameters such as seismic wave speed, attenuation, electrical conductivity and magnetic susceptibility with a main focus on seismic properties. Therefore, we follow a comprehensive approach involving

  16. Geophysical Anomalies and Earthquake Prediction

    Science.gov (United States)

    Jackson, D. D.

    2008-12-01

    Finding anomalies is easy. Predicting earthquakes convincingly from such anomalies is far from easy. Why? Why have so many beautiful geophysical abnormalities not led to successful prediction strategies? What is earthquake prediction? By my definition it is convincing information that an earthquake of specified size is temporarily much more likely than usual in a specific region for a specified time interval. We know a lot about normal earthquake behavior, including locations where earthquake rates are higher than elsewhere, with estimable rates and size distributions. We know that earthquakes have power law size distributions over large areas, that they cluster in time and space, and that aftershocks follow with power-law dependence on time. These relationships justify prudent protective measures and scientific investigation. Earthquake prediction would justify exceptional temporary measures well beyond those normal prudent actions. Convincing earthquake prediction would result from methods that have demonstrated many successes with few false alarms. Predicting earthquakes convincingly is difficult for several profound reasons. First, earthquakes start in tiny volumes at inaccessible depth. The power law size dependence means that tiny unobservable ones are frequent almost everywhere and occasionally grow to larger size. Thus prediction of important earthquakes is not about nucleation, but about identifying the conditions for growth. Second, earthquakes are complex. They derive their energy from stress, which is perniciously hard to estimate or model because it is nearly singular at the margins of cracks and faults. Physical properties vary from place to place, so the preparatory processes certainly vary as well. Thus establishing the needed track record for validation is very difficult, especially for large events with immense interval times in any one location. Third, the anomalies are generally complex as well. Electromagnetic anomalies in particular require

  17. Methodology of Detailed Geophysical Examination of the Areas of World Recognized Religious and Cultural Artifacts

    Science.gov (United States)

    Eppelbaum, Lev

    2010-05-01

    the low altitudes (3-5 meters) will help geophysical cover all the studied area with a regular observation step (Eppelbaum, 2008). At the final step all these measurements (including results of the previous works) could be compiled to 4D models of different geophysical parameters (Eppelbaum and Ben-Avraham, 2002; Eppelbaum et al., 2010). Analysis of temperature field in the boreholes drilled in the vicinity of the studied site will permit to estimate the temperature (e.g., Eppelbaum et al., 2006c) in the historical period when this artifact was constructed and, correspondingly, utilize this characteristic for investigation of mechanical and other properties of the ancient building material. Studying of temporal variations of magnetic (e.g., Finkelstein and Eppelbaum) and VLF fields can be also used for determination of nature of some buried ancient remains. The geophysical investigations must be combined with geochemical, paleostructural, paleobiogeographical, paleomorphological and other methods (Eppelbaum et al., 2010). Application of informational parameters (Khesin et al., 1996; Eppelbaum et al., 2003b) will permit to present all available data by the use of integral convolution units. REFERENCES Eppelbaum, L.V., 1999. Quantitative interpretation of resistivity anomalies using advanced methods developed in magnetic prospecting. Trans. of the XXIV General Assembly of the Europ. Geoph. Soc., Strasburg 1 (1), p.166. Eppelbaum, L.V., 2000. Applicability of geophysical methods for localization of archaeological targets: An introduction. Geoinformatics, 11, No.1, 19-28. Eppelbaum, L.V., 2005. Multilevel observations of magnetic field at archaeological sites as additional interpreting tool. Proceed. of the 6th Conference of Archaeological Prospection, Roma, Italy, 4 pp. Eppelbaum, L.V., 2008. Remote operated vehicle geophysical survey using magnetic and VLF methods: proposed schemes for data processing and interpretation. Proceed. of the Symp. on the Application of

  18. Fundamentals of Geophysical Fluid Dynamics

    Science.gov (United States)

    McWilliams, James C.

    2006-07-01

    Earth's atmosphere and oceans exhibit complex patterns of fluid motion over a vast range of space and time scales. These patterns combine to establish the climate in response to solar radiation that is inhomogeneously absorbed by the materials comprising air, water, and land. Spontaneous, energetic variability arises from instabilities in the planetary-scale circulations, appearing in many different forms such as waves, jets, vortices, boundary layers, and turbulence. Geophysical fluid dynamics (GFD) is the science of all these types of fluid motion. This textbook is a concise and accessible introduction to GFD for intermediate to advanced students of the physics, chemistry, and/or biology of Earth's fluid environment. The book was developed from the author's many years of teaching a first-year graduate course at the University of California, Los Angeles. Readers are expected to be familiar with physics and mathematics at the level of general dynamics (mechanics) and partial differential equations. Covers the essential GFD required for atmospheric science and oceanography courses Mathematically rigorous, concise coverage of basic theory and applications to both oceans and atmospheres Author is a world expert; this book is based on the course he has taught for many years Exercises are included, with solutions available to instructors from solutions@cambridge.org

  19. Statistical interpretation of geochemical data

    International Nuclear Information System (INIS)

    Carambula, M.

    1990-01-01

    Statistical results have been obtained from a geochemical research from the following four aerial photographies Zapican, Carape, Las Canias, Alferez. They have been studied 3020 samples in total, to 22 chemical elements using plasma emission spectrometry methods.

  20. Geophysical investigations at ORNL solid waste storage area 3

    International Nuclear Information System (INIS)

    Rothschild, E.R.; Switek, J.; Llopis, J.L.; Farmer, C.D.

    1985-07-01

    Geophysical investigations at ORNL solid waste storage area 3 have been carried out. The investigations included very-low-frequency-electromagnetic resistivity (VLF-EM), electrical resistivity, and seismic refraction surveys. The surveys resulted in the measurement of basic geophysical rock properties, as well as information on the depth of weathering and the configuration of the bedrock surface beneath the study area. Survey results also indicate that a number of geophysical anomalies occur in the shallow subsurface at the site. In particular, a linear feature running across the geologic strike in the western half of the waste disposal facility has been identified. This feature may conduct water in the subsurface. The geophysical investigations are part of an ongoing effort to characterize the site's hydrogeology, and the data presented will be valuable in directing future drilling and investigations at the site. 10 refs., 6 figs

  1. Geochemical studies in watersheds expanded

    Science.gov (United States)

    Church, M. Robbins

    In the past, geochemical research in forested watersheds has focused on understanding the basic processes that occur in soils and rocks. Watershed geochemical processes, however, are greatly influenced by, and in turn, greatly influence, both organisms and biological process in soils, and hydrologic responses of catchments. To date, geochemical research has dealt principally with basic chemical processes in soils and rocks, and much less with questions concerning hydrologic routing through catchments and the effects such routing has on temporal variation in chemical composition of surface waters.Research on flow generation in catchments has focused on intensive field studies on plots, hillslope sections, and small catchments, with extension to larger scales necessarily involving the application of conceptual models that might (or might not) be valid. The acquisition of direct experimental evidence (for example, verifying flow generation mechanisms) on larger-scale watersheds has always been problematic. Although geochemists understand that the explanation of some geochemical observations requires that flow pathways be explicitly identified, and hydrologists understand that flow generation can be better elucidated if the geochemical history of waters is known, critical integrated communication between the disciplines is often lacking. In turn, biologists require physical and geochemical information to interpret biological effects in watersheds, and hydrologists and geochemists need to be aware of the effects of biological processes on hydrochemical response of catchments.

  2. Attenuated geophysical signatures associated with ongoing remediation efforts at Wurtsmith Air Force Base, Oscoda, Michigan

    Science.gov (United States)

    Che-Alota, V.; Atekwana, E. A.; Sauck, W. A.; Nolan, J. T.; Slater, L. D.

    2007-12-01

    Previous geophysical investigations (1996, 1997, 2003, and 2004) conducted at the decommissioned Wurtsmith Air Force Base former Fire Training Cell (FT-02) showed a clearly defined high conductivity anomaly associated with hydrocarbon contaminants in the vadose zone and ground water near the source area. The source of the geophysical anomalies was attributed to biogeochemical modifications of the contaminated zone resulting from intrinsic bioremediation. During these previous surveys, ground penetrating radar (GPR) data showed a zone of attenuated GPR reflections extending from the vadose zone to below the water table. Self potential data (SP) data defined a positive anomaly coincident with the hydrochemically defined plume, while electrical resistivity data showed anomalously high conductivity within the zone of impact. In 2007, another integrated geophysical study of the site was conducted. GPR, SP, electrical resistivity, and induced polarization surveys were conducted with expectations of achieving similar results as the past surveys. However, preliminary assessment of the data shows a marked decrease in electrical conductivity and SP response over the plume. GPR data still showed the attenuated signals, but the zone of attenuation was only observed below the water table. We attribute the attenuation of the observed geophysical anomalies to ongoing soil vapor extraction initiated in 2003. Significant removal of the contaminant mass by the vapor extraction system has altered the subsurface biogeochemical conditions and these changes were documented by the 2007 geophysical and geochemical data. The results of this study show that the attenuation of the contaminant plume is detectable with geophysical methods.

  3. Geophysics of Small Planetary Bodies

    Science.gov (United States)

    Asphaug, Erik I.

    1998-01-01

    As a SETI Institute PI from 1996-1998, Erik Asphaug studied impact and tidal physics and other geophysical processes associated with small (low-gravity) planetary bodies. This work included: a numerical impact simulation linking basaltic achondrite meteorites to asteroid 4 Vesta (Asphaug 1997), which laid the groundwork for an ongoing study of Martian meteorite ejection; cratering and catastrophic evolution of small bodies (with implications for their internal structure; Asphaug et al. 1996); genesis of grooved and degraded terrains in response to impact; maturation of regolith (Asphaug et al. 1997a); and the variation of crater outcome with impact angle, speed, and target structure. Research of impacts into porous, layered and prefractured targets (Asphaug et al. 1997b, 1998a) showed how shape, rheology and structure dramatically affects sizes and velocities of ejecta, and the survivability and impact-modification of comets and asteroids (Asphaug et al. 1998a). As an affiliate of the Galileo SSI Team, the PI studied problems related to cratering, tectonics, and regolith evolution, including an estimate of the impactor flux around Jupiter and the effect of impact on local and regional tectonics (Asphaug et al. 1998b). Other research included tidal breakup modeling (Asphaug and Benz 1996; Schenk et al. 1996), which is leading to a general understanding of the role of tides in planetesimal evolution. As a Guest Computational Investigator for NASA's BPCC/ESS supercomputer testbed, helped graft SPH3D onto an existing tree code tuned for the massively parallel Cray T3E (Olson and Asphaug, in preparation), obtaining a factor xIO00 speedup in code execution time (on 512 cpus). Runs which once took months are now completed in hours.

  4. Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range

    International Nuclear Information System (INIS)

    Koppenjan, S.; Martinez, M.

    1994-01-01

    The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteria for the development of geophysical technologies and techniques. The US DOE's Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a ''chirped'' FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site

  5. Development of Geophysical Ideas and Institutions in Ottoman Empire

    Science.gov (United States)

    Ozcep, Ferhat; Ozcep, Tazegul

    2015-04-01

    In Anatolia, the history of geophysical sciences may go back to antiquity (600 BC), namely the period when Thales lived in Magnesia (Asia Minor). In the modern sense, geophysics started with geomagnetic works in the 1600s. The period between 1600 and 1800 includes the measurement of magnetic declination, inclination and magnetic field strength. Before these years, there is a little information, such as how to use a compass, in the Kitab-i Bahriye (the Book of Navigation) of Piri Reis, who is one of the most important mariners of the Ottoman Empire. However, this may not mean that magnetic declination was generally understood. The first scientific book relating to geophysics is the book Fuyuzat-i Miknatissiye that was translated by Ibrahim Müteferrika and printed in 1731. The subject of this book is earth's magnetism. There is also information concerning geophysics in the book Cihannuma (Universal Geography) that was written by Katip Celebi and in the book Marifetname written by Ibrahim Hakki Erzurumlu, but these books are only partly geophysical books. In Istanbul the year 1868 is one of the most important for geophysical sciences because an observatory called Rasathane-i Amire was installed in the Pera region of this city. At this observatory the first systematic geophysical observations such as meteorological, seismological and even gravimetrical were made. There have been meteorological records in Anatolia since 1839. These are records of atmospheric temperature, pressure and humidity. In the Ottoman Empire, the science of geophysics is considered as one of the natural sciences along with astronomy, mineralogy, geology, etc., and these sciences are included as a part of physics and chemistry.

  6. Notes on the history of geophysics in the Ottoman Empire

    Science.gov (United States)

    Ozcep, F.; Ozcep, T.

    2014-09-01

    In Anatolia, the history of geophysical sciences may go back to antiquity (600 BC), namely the period when Thales lived in Magnesia (Asia Minor). In the modern sense, geophysics started with geomagnetic works in the 1600s. The period between 1600 and 1800 includes the measurement of magnetic declination, inclination and magnetic field strength. Before these years, there is a little information, such as how to use a compass, in the Kitab-i Bahriye (the Book of Navigation) of Piri Reis, who is one of the most important mariners of the Ottoman Empire. However, this may not mean that magnetic declination was generally understood. The first scientific book relating to geophysics is the book Fuyuzat-i Miknatissiye that was translated by Ibrahim Müteferrika and printed in 1731. The subject of this book is earth's magnetism. There is also information concerning geophysics in the book Cihannuma (Universal Geography) that was written by Katip Celebi and in the book Marifetname written by Ibrahim Hakki Erzurumlu, but these books are only partly geophysical books. In Istanbul the year 1868 is one of the most important for geophysical sciences because an observatory called Rasathane-i Amire was installed in the Pera region of this city. At this observatory the first systematic geophysical observations such as meteorological, seismological and even gravimetrical were made. There have been meteorological records in Anatolia since 1839. These are records of atmospheric temperature, pressure and humidity. In the Ottoman Empire, the science of geophysics is considered as one of the natural sciences along with astronomy, mineralogy, geology, etc., and these sciences are included as a part of physics and chemistry.

  7. Integrated Research and Capacity Building in Geophysics

    Science.gov (United States)

    Willemann, R. J.; Lerner-Lam, A.; Nyblade, A.

    2008-05-01

    There have been special opportunities over the past several years to improve the ways that newly-constructed geophysical observatories in Southeast Asia and the Americas are linked with educational and civil institutions. Because these opportunities have been only partially fulfilled, there remains the possibility that new networks will not fully address desired goals or even lose operational capabilities. In contrast, the AfricaArray project continues to progress towards goals for linkages among education, research, mitigation and observatories. With support from the Office of International Science and Education at the US National Science Foundation, we convened a workshop to explore lessons learned from the AfricaArray experience and their relevance to network development opportunities in other regions. We found closer parallels than we expected between geophysical infrastructure in the predominantly low income countries of Africa with low risk of geophysical disasters and the mostly middle-income countries of Southeast Asia and the Americas with high risk of geophysical disasters. Except in larger countries of South America, workshop participants reported that there are very few geophysicists engaged in research and observatory operations, that geophysical education programs are nearly non-existent even at the undergraduate university level, and that many monitoring agencies continue to focus on limited missions even though closer relationships researchers could facilitate new services that would make important contributions to disaster mitigation and sustainable operations. Workshop participants began discussing plans for international research collaborations that, unlike many projects of even the recent past, would include long-term capacity building and disaster mitigation among their goals. Specific project objectives would include national or regional hazard mapping, development of indigenous education programs, training to address the needs of local

  8. Geochemical exploration for uranium

    International Nuclear Information System (INIS)

    Rose, A.W.

    1977-01-01

    The processes and types of dispersion that produce anomalies in stream water, stream sediment, and ground water, and the factors that must be considered in planning and interpreting geochemical surveys are reviewed. Examples of surveys near known deposits show the types of results to be expected. Background values depend mainly on the content of U in rocks of the drainage area. In igneous rocks, U tends to increase with potassium from ultramafic rocks (0.01 ppM) to granitic rocks (1 to 5 ppM). Some alkalic rocks have unusually high contents of U (15 to 100 ppM). Uranium-rich provinces marked by igneous rocks unusually rich in U are recognized in several areas and appear to have a deep crustal or mantle origin. In western U.S., many tertiary tuffaceous rocks have a high U content. Sandstones, limestones, and many shales approximate the crustal abundance at 0.5 to 4 ppM, but black shales, phosphates, and some organic materials are notably enriched in U. Uranium is very soluble in most oxidizing waters at the earth's surface, but is precipitated by reducing agents (organic matter, H 2 S) and adsorbed by organic material and some Fe oxides. In most surface and ground waters, U correlates approximately with the total dissolved solids, conductivity, and bicarbonate concentration of the water, and with the U content of rocks it comes into contact with. Most surveys of stream water near known districts show distinct anomalies extending a few km to tens of km downstream. A complication with water is the large variability with time, up to x 50, as a result of changes in the ratio of ground water to direct runoff, and changes in rate of oxidation and leaching. Collection and analysis of water samples also pose some difficulties

  9. Collected radiochemical and geochemical procedures

    Energy Technology Data Exchange (ETDEWEB)

    Kleinberg, J [comp.

    1990-05-01

    This revision of LA-1721, 4th Ed., Collected Radiochemical Procedures, reflects the activities of two groups in the Isotope and Nuclear Chemistry Division of the Los Alamos National Laboratory: INC-11, Nuclear and radiochemistry; and INC-7, Isotope Geochemistry. The procedures fall into five categories: I. Separation of Radionuclides from Uranium, Fission-Product Solutions, and Nuclear Debris; II. Separation of Products from Irradiated Targets; III. Preparation of Samples for Mass Spectrometric Analysis; IV. Dissolution Procedures; and V. Geochemical Procedures. With one exception, the first category of procedures is ordered by the positions of the elements in the Periodic Table, with separate parts on the Representative Elements (the A groups); the d-Transition Elements (the B groups and the Transition Triads); and the Lanthanides (Rare Earths) and Actinides (the 4f- and 5f-Transition Elements). The members of Group IIIB-- scandium, yttrium, and lanthanum--are included with the lanthanides, elements they resemble closely in chemistry and with which they occur in nature. The procedures dealing with the isolation of products from irradiated targets are arranged by target element.

  10. Basic elements of nuclear geophysics

    International Nuclear Information System (INIS)

    Nordemann, D.J.R.; Pereira, E.B.

    1984-01-01

    Nuclear Geophysics applies the nuclear radiation detection methodology to the geosciences, specially to study the dynamical processes of the lithosphere, the hydrosphere and the atmosphere as well as some aspects of planetology and astrophysics. Here the main methods are described: alpha-ray and gamma-ray spectrometry, the interaction of alpha and gamma radiation with matter and the detectors used (grid chambers, surface barrier silicon detector for alpha radiation; and sodium iodide thallium activated phosphors, hyperpure and lithium drifted germanium semiconductor detectors for gamma radiation). The principal applications of Nuclear Geophysics are given as examples to ilustrate the use of the methods described. (AUthor) [pt

  11. Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites - East Fork Valley Range Complex, Former Camp Hale

    Science.gov (United States)

    2016-04-01

    Technical Report Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites - East Fork Valley...AECOM Distribution Statement A FINAL REPORT Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites East...NUMBER (Include area code) 12-06-2013 Final Report May - November 2014 Demonstration of Advanced Geophysics and Classification Methods on Munitions

  12. Applications of geophysical methods to volcano monitoring

    Science.gov (United States)

    Wynn, Jeff; Dzurisin, Daniel; Finn, Carol A.; Kauahikaua, James P.; Lahusen, Richard G.

    2006-01-01

    The array of geophysical technologies used in volcano hazards studies - some developed originally only for volcano monitoring - ranges from satellite remote sensing including InSAR to leveling and EDM surveys, campaign and telemetered GPS networks, electronic tiltmeters and strainmeters, airborne magnetic and electromagnetic surveys, short-period and broadband seismic monitoring, even microphones tuned for infrasound. They include virtually every method used in resource exploration except large-scale seismic reflection. By “geophysical ” we include both active and passive methods as well as geodetic technologies. Volcano monitoring incorporates telemetry to handle high-bandwith cameras and broadband seismometers. Critical geophysical targets include the flux of magma in shallow reservoir and lava-tube systems, changes in active hydrothermal systems, volcanic edifice stability, and lahars. Since the eruption of Mount St. Helens in Washington State in 1980, and the eruption at Pu’u O’o in Hawai’i beginning in 1983 and still continuing, dramatic advances have occurred in monitoring technology such as “crisis GIS” and lahar modeling, InSAR interferograms, as well as gas emission geochemistry sampling, and hazards mapping and eruption predictions. The on-going eruption of Mount St. Helens has led to new monitoring technologies, including advances in broadband Wi-Fi and satellite telemetry as well as new instrumentation. Assessment of the gap between adequate monitoring and threat at the 169 potentially dangerous Holocene volcanoes shows where populations are dangerously exposed to volcanic catastrophes in the United States and its territories . This paper focuses primarily on Hawai’ian volcanoes and the northern Pacific and Cascades volcanoes. The US Geological Survey, the US National Park System, and the University of Utah cooperate in a program to monitor the huge Yellowstone volcanic system, and a separate observatory monitors the restive Long Valley

  13. Geophysics applications in critical zone science: emerging topics.

    Science.gov (United States)

    Pachepsky, Y. A.; Martinez, G.; Guber, A.; Walthall, C. L.; Vereecken, H.

    2012-12-01

    Geophysical studies have resulted in remarkable advances in characterization of critical zone. The geophysics applications uncover the relationships between structure and function in subsurface as they seek to define subsurface structural units with individual properties of retention and transmission of water, energy, solutes, electrical charge, etc. Several focal points of the research have emerged as the knowledge base of the critical zone geophysics grows. Time-lapse or multiple geophysical surveys admittedly improve the subsurface characterization. One of intriguing possibilities here is to use the temporal variation in geophysical parameters among time-lapse surveys directly to model spatial variation in soil properties affecting soil-water contents. Because critical phenomena causing erratic routing have been recently discovered in hillslope subsurface flow networks, it remains to be seen whether the time-lapse imagery depicts the same flow network if weather conditions are seemingly similar. High-frequency network observations usually reveal the temporal stability patterns in soil variables, including water contents, CO2 fluxes, etc. It becomes clear that these patterns can be described with spatiotemporal geostatistics models, and the opportunity arises to infer the spatial correlation structure of soil parameters from temporal variations of soil dynamic variables. There are indications that the spatial correlation structures of the geophysical parameters and soil/plant variables can be similar even though the correlations between these parameters are low. This may open additional avenues for mapping sparsely measured soil and plant variables. Fallacies of scale in geophysical depicting subsurface structural units and patterns are far from being understood. Soil state variables affect geophysical retrieval in nonlinear ways, and therefore scale effects in retrievals are warranted. For this reason, the strength and type of dependencies between geophysical

  14. Reproducibility of geochemical and climatic signals in the Atlantic coral Montastraea faveolata

    Science.gov (United States)

    Smith, Joseph M.; Quinn, T.M.; Helmle, K.P.; Halley, R.B.

    2006-01-01

    Monthly resolved, 41-year-long stable isotopic and elemental ratio time series were generated from two separate heads of Montastraea faveolata from Looe Key, Florida, to assess the fidelity of using geochemical variations in Montastraea, the dominant reef-building coral of the Atlantic, to reconstruct sea surface environmental conditions at this site. The stable isotope time series of the two corals replicate well; mean values of ??18O and ??13C are indistinguishable between cores (compare 0.70??? versus 0.68??? for ??13C and -3.90??? versus - 3.94??? for ??18O). Mean values from the Sr/Ca time series differ by 0.037 mmol/mol, which is outside of analytical error and indicates that nonenvironmental factors are influencing the coral Sr/ Ca records at Looe Key. We have generated significant ?? 18O-sea surface temperature (SST) (R = -0.84) and Sr/ Ca-SST (R = -0.86) calibration equations at Looe Key; however, these equations are different from previously published equations for Montastraea. Variations in growth parameters or kinetic effects are not sufficient to explain either the observed differences in the mean offset between Sr/Ca time series or the disagreement between previous calibrations and our calculated ??18O-SST and Sr/Ca-SST relationships. Calibration differences are most likely due to variations in seawater chemistry in the continentally influenced waters at Looe Key. Additional geochemical replication studies of Montastraea are needed and should include multiple coral heads from open ocean localities complemented whenever possible by seawater chemistry determinations. Copyright 2006 by the American Geophysical Union.

  15. Activities and Plan of the Center for Geophysics (Beijing from WDC to WDS

    Directory of Open Access Journals (Sweden)

    Fenglin Peng

    2013-01-01

    Full Text Available In this report we introduce the development of the WDC for Geophysics, Beijing included our activities in the electronic Geophysical Year (eGY and in the transition period from WDC to WDS. We also present our future plans. We have engaged in the development of geophysical informatics and related data science. We began the data visualization of geomagnetic fields in the GIS system. Our database has been expanded from geomagnetic data to the data of solid geophysics, including geothermal data, gravity data, and the records of aurora sightings in ancient China. We also joined the study of the history of the development of geophysics in China organized by the Chinese Geophysical Society (CGS.

  16. Conceptual Design of Geophysical Microsatellite

    Directory of Open Access Journals (Sweden)

    Matviyenko, S.A.

    2014-10-01

    Full Text Available The article covers the issue of Earth gravitational field (EGF parameters measurement from space. The radiophysical method of measurement of gravitational frequency shift of electromagnetic radiation using existent GNSS and its two variants are developed by the author. The designlayout drawing of geophysical microsatellite, which implements the radiophysical method of EGF measurement and provides Earth plasmasphere and magnetosphere monitoring, is offered.

  17. SAGEEP '96: Proceedings of the symposium on the application of geophysics to engineering and environmental problems

    International Nuclear Information System (INIS)

    Bell, R.S.; Cramer, M.H.

    1996-01-01

    This document contains the Proceedings of the Symposium on the Application of Geophysics to Engineering and Environmental Problems which was held on April 28-May 2, 1996 in Keystone, Colorado, USA. Topics covered in the presentations include: Innovations in Electrical and Electromagnetic Methods, Near surface Seismic Applications, Environmental Aspects of Abandoned and Inactive Mines, Hydrogeology, The Search for Buried Objects, GPR Applications, Geotechnical Applications, Computer Applications and Advancements, Borehole and Tomographic Studies,Site Assessments, and Environmental Geophysics in Finland. Poster presentations also covered a variety of topics including electromagnetic mapping of karstic aquifers, mapping of mine subsidence, geophysical surveys of abandoned reactor sites, and several other applications of geophysics

  18. Geophysics & Geology Inspected.

    Science.gov (United States)

    Neale, E. R. W.

    1981-01-01

    Summarizes findings of a recently published report of the Canadian Geoscience Council, which includes the following topics regarding college geology: facilities; teaching; undergraduate enrollments; postgraduate enrollments; geologic research; and integration of Canadian geoscience with other countries. (CS)

  19. Unleashing Geophysics Data with Modern Formats and Services

    Science.gov (United States)

    Ip, Alex; Brodie, Ross C.; Druken, Kelsey; Bastrakova, Irina; Evans, Ben; Kemp, Carina; Richardson, Murray; Trenham, Claire; Wang, Jingbo; Wyborn, Lesley

    2016-04-01

    Geoscience Australia (GA) is the national steward of large volumes of geophysical data extending over the entire Australasian region and spanning many decades. The volume and variety of data which must be managed, coupled with the increasing need to support machine-to-machine data access, mean that the old "click-and-ship" model delivering data as downloadable files for local analysis is rapidly becoming unviable - a "big data" problem not unique to geophysics. The Australian Government, through the Research Data Services (RDS) Project, recently funded the Australian National Computational Infrastructure (NCI) to organize a wide range of Earth Systems data from diverse collections including geoscience, geophysics, environment, climate, weather, and water resources onto a single High Performance Data (HPD) Node. This platform, which now contains over 10 petabytes of data, is called the National Environmental Research Data Interoperability Platform (NERDIP), and is designed to facilitate broad user access, maximise reuse, and enable integration. GA has contributed several hundred terabytes of geophysical data to the NERDIP. Historically, geophysical datasets have been stored in a range of formats, with metadata of varying quality and accessibility, and without standardised vocabularies. This has made it extremely difficult to aggregate original data from multiple surveys (particularly un-gridded geophysics point/line data) into standard formats suited to High Performance Computing (HPC) environments. To address this, it was decided to use the NERDIP-preferred Hierarchical Data Format (HDF) 5, which is a proven, standard, open, self-describing and high-performance format supported by extensive software tools, libraries and data services. The Network Common Data Form (NetCDF) 4 API facilitates the use of data in HDF5, whilst the NetCDF Climate & Forecasting conventions (NetCDF-CF) further constrain NetCDF4/HDF5 data so as to provide greater inherent interoperability

  20. Postcards from Mars: Insights into Martian Geochemical Processes from the Curiosity Rover

    OpenAIRE

    Leshin, L. A.; Grotzinger, J. P.; Blake, D. F.; Gellert, R.; Mahaffy, P. R.; Wiens, R. C.; Maurice, S.

    2013-01-01

    With the successful landing of the Mars Curiosity Rover in August 2012, we now have the most capable geochemical laboratory ever to travel to another planet roving Mars’ Gale crater. The geochemical instrument suite includes the Chemistry Camera (ChemCam), which uses a laser to vaporize geologic targets and performs atomic emission spectroscopy on the vapor from distances of up to 7m. This provides a geochemical surveying capability that enables rapid identification of...

  1. Geophysical borehole logging test procedure: Final draft

    International Nuclear Information System (INIS)

    1986-09-01

    The purpose of geophysical borehole logging from the At-Depth Facility (ADF) is to provide information which will assist in characterizing the site geologic conditions and in classifying the engineering characteristics of the rock mass in the vicinity of the ADF. The direct goals of borehole logging include identification of lithologic units and their correlation from hole to hole, identification of fractured or otherwise porous or permeable zones, quantitative or semi-quantitative estimation of various formation properties, and evaluation of factors such as the borehole diameter and orientation. 11 figs., 4 tabs

  2. Geophysical investigation and characterization with USRADS

    International Nuclear Information System (INIS)

    Flynn, C.R.; Blair, M.S.; Nyquist, J.E.

    1992-01-01

    This paper describes two recent case histories in which commercially available geophysical instruments were used with an innovative tracking and mapping system called USRADS (UltraSonic Ranging And Data System) that automates data location and collection. USRADS uses ultrasonics to provide real-time surveyor positioning and radio links to transmit the surveyor data to an on-site computer for storage and real-time display. USRADS uses a standard 386 computer for data collection and includes real-time color display of the findings. It also includes numerous analysis and display formats for on-site, as well as utilities to facilitate post-process analysis of the findings. The objective of one project was to locate several suspect waste disposal trenches and to map their boundaries. The second was to locate and map the presence of subsurface unexploded ordinance (UXO) at a suspect artillery impact area. A Geonics EM31 terrain conductivity meter interfaced to USRADS was used to map the suspect trenches. A Schonstedt GA-52C magnetometer interfaced to USRADS was used to map the subsurface UXO. Correlation of findings to known site features and additional knowledge about the sites indicates that these efforts did locate and map the geophysical features including the suspect waste trenches and the subsurface UXO. Images of the findings generated on-site and during post-processing are included

  3. Geophysical Institute. Biennial report, 1993-1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    The 1993-1994 Geophysical Institute Biennial Report was published in November 1995 by the Geophysical Institute of the University of Alaska Fairbanks. It contains an overview of the Geophysical Institute, the Director`s Note, and research presentations concerning the following subjects: Scientific Predictions, Space Physics, Atmospheric Sciences, Snow, Ice and Permafrost, Tectonics and Sedimentation, Seismology, Volcanology, Remote Sensing, and other projects.

  4. A Spatially Constrained Multi-autoencoder Approach for Multivariate Geochemical Anomaly Recognition

    Science.gov (United States)

    Lirong, C.; Qingfeng, G.; Renguang, Z.; Yihui, X.

    2017-12-01

    Separating and recognizing geochemical anomalies from the geochemical background is one of the key tasks in geochemical exploration. Many methods have been developed, such as calculating the mean ±2 standard deviation, and fractal/multifractal models. In recent years, deep autoencoder, a deep learning approach, have been used for multivariate geochemical anomaly recognition. While being able to deal with the non-normal distributions of geochemical concentrations and the non-linear relationships among them, this self-supervised learning method does not take into account the spatial heterogeneity of geochemical background and the uncertainty induced by the randomly initialized weights of neurons, leading to ineffective recognition of weak anomalies. In this paper, we introduce a spatially constrained multi-autoencoder (SCMA) approach for multivariate geochemical anomaly recognition, which includes two steps: spatial partitioning and anomaly score computation. The first step divides the study area into multiple sub-regions to segregate the geochemical background, by grouping the geochemical samples through K-means clustering, spatial filtering, and spatial constraining rules. In the second step, for each sub-region, a group of autoencoder neural networks are constructed with an identical structure but different initial weights on neurons. Each autoencoder is trained using the geochemical samples within the corresponding sub-region to learn the sub-regional geochemical background. The best autoencoder of a group is chosen as the final model for the corresponding sub-region. The anomaly score at each location can then be calculated as the euclidean distance between the observed concentrations and reconstructed concentrations of geochemical elements.The experiments using the geochemical data and Fe deposits in the southwestern Fujian province of China showed that our SCMA approach greatly improved the recognition of weak anomalies, achieving the AUC of 0.89, compared

  5. Field Geophysics at SAGE: Strategies for Effective Education

    Science.gov (United States)

    Braile, L. W.; Baldridge, W. S.; Jiracek, G. R.; Biehler, S.; Ferguson, J. F.; Pellerin, L.; McPhee, D. K.; Bedrosian, P. A.; Snelson, C. M.; Hasterok, D. P.

    2011-12-01

    SAGE (Summer of Applied Geophysical Experience) is a unique program of education and research in geophysical field methods for undergraduate and graduate students from any university and for professionals. The core program is held for 4 weeks each summer in New Mexico and for an additional week in the following academic year in San Diego for U.S. undergraduates supported by the NSF Research Experience for Undergraduates (REU) program. Since SAGE was initiated in 1983, 730 students have participated in the program. NSF REU funding for SAGE began in 1990 and 319 REU students have completed SAGE through 2011. The primary objectives of SAGE are to teach the major geophysical exploration methods (seismic, gravity, magnetics, electromagnetics); apply these methods to the solution of specific problems (environmental, archaeological, hydrologic, geologic structure and stratigraphy); gain experience in processing, modeling and interpretation of geophysical data; and integrate the geophysical models and interpretations with geology. Additional objectives of SAGE include conducting research on the Rio Grande rift of northern New Mexico, and providing information on geophysics careers and professional development experiences to SAGE participants. Successful education, field and research strategies that we have implemented over the years include: 1. learn by doing; 2. mix lecture/discussion, field work, data processing and analysis, modeling and interpretation, and presentation of results; 3. a two-tier team approach - method/technique oriented teams and interpretation/integration teams (where each team includes persons representing different methods), provides focus, in-depth study, opportunity for innovation, and promotes teamwork and a multi-disciplinary approach; 4. emphasis on presentations/reports - each team (and all team members) make presentation, each student completes a written report; 5. experiment design discussion - students help design field program and consider

  6. Concerning evaluation of eco-geochemical background in remediation strategy

    Science.gov (United States)

    Korobova, Elena; Romanov, Sergey

    2015-04-01

    The geochemical concept of biosphere developed by V.I. Vernadsky states the geological role of the living organisms in the course of their active chemical interaction with the inert matter (Vernadsky, 1926, 1960). Basing on this theory it is reasonable to suggest that coevolution of living organisms and their environment led to development of the dynamically stable biogeocenoses precisely adequate to their geochemical environment. Soil cover was treated by V.I. Vernadsky as a balanced bio-inert matter resulting from this interaction. Appearance of human mind and then a civilization led to global expansion of human beings, first able to survive in unfavorable geochemical conditions and then starting chemical transformation of the environment to satisfy the growing demands of mankind in food and energy. The residence in unfavorable environment and local contamination was followed by appearance of endemic diseases of plants, animals and man. Therefore zonal, regional and local chemical composition of the soil cover formed in natural conditions may be used for estimation of the optimum geochemical background, most adequate for the corresponding zonal biogeocenoses and species. Moreover, the natural geochemical background and technogenic fields have unequal spatial structure and this facilitates their identification that may be relatively easy realized in remediation strategy. On the assumption of the foregoing, the adequate methodical approach to remediation of technogenically affected areas should account of the interaction of the existing natural and the newly formed technogenic geochemical fields and include the following steps: 1) the study and mapping of geochemical structure of the natural geochemical background basing on soil maps; 2) the study of contaminants and mapping spatial distribution of technogenic releases; 3) construction of risk maps for the target risk groups with due regard to natural ecological threshold concentration in context of risk degree for

  7. Improved extraction of hydrologic information from geophysical data through coupled hydrogeophysical inversion

    Energy Technology Data Exchange (ETDEWEB)

    Hinnell, A.C.; Ferre, T.P.A.; Vrugt, J.A.; Huisman, J.A.; Moysey, S.; Rings, J.; Kowalsky, M.B.

    2009-11-01

    There is increasing interest in the use of multiple measurement types, including indirect (geophysical) methods, to constrain hydrologic interpretations. To date, most examples integrating geophysical measurements in hydrology have followed a three-step, uncoupled inverse approach. This approach begins with independent geophysical inversion to infer the spatial and/or temporal distribution of a geophysical property (e.g. electrical conductivity). The geophysical property is then converted to a hydrologic property (e.g. water content) through a petrophysical relation. The inferred hydrologic property is then used either independently or together with direct hydrologic observations to constrain a hydrologic inversion. We present an alternative approach, coupled inversion, which relies on direct coupling of hydrologic models and geophysical models during inversion. We compare the abilities of coupled and uncoupled inversion using a synthetic example where surface-based electrical conductivity surveys are used to monitor one-dimensional infiltration and redistribution.

  8. NOAA and MMS Marine Minerals Geochemical Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Minerals Geochemical Database was created by NGDC as a part of a project to construct a comprehensive computerized bibliography and geochemical database...

  9. Oak Ridge Geochemical Reconnaissance Program

    International Nuclear Information System (INIS)

    Arendt, J.W.

    1977-03-01

    The Oak Ridge reconnaissance program is responsible for the geochemical survey in a 12-state area covering Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Michigan, Iowa, Indiana, and Illinois as part of the National Uranium Resource Evaluation Program. The program concept is outlined and the planning and organization of the program is discussed

  10. Geophysical Investigations of Archaeological Resources in Southern Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Brenda Ringe Pace; Gail Heath; Clark Scott; Carlan McDaniel

    2005-10-01

    At the Idaho National Laboratory and other locations across southern Idaho, geophysical tools are being used to discover, map, and evaluate archaeological sites. A variety of settings are being explored to expand the library of geophysical signatures relevant to archaeology in the region. Current targets of interest include: prehistoric archaeological features in open areas as well as lava tube caves, historical structures and activity areas, and emigrant travel paths. We draw from a comprehensive, state of the art geophysical instrumentation pool to support this work. Equipment and facilities include ground penetrating radar, electromagnetic and magnetic sensors, multiple resistivity instruments, advanced positioning instrumentation, state of the art processing and data analysis software, and laboratory facilities for controlled experiments.

  11. Geophysical interpretation using integral equations

    CERN Document Server

    Eskola, L

    1992-01-01

    Along with the general development of numerical methods in pure and applied to apply integral equations to geophysical modelling has sciences, the ability improved considerably within the last thirty years or so. This is due to the successful derivation of integral equations that are applicable to the modelling of complex structures, and efficient numerical algorithms for their solution. A significant stimulus for this development has been the advent of fast digital computers. The purpose of this book is to give an idea of the principles by which boundary-value problems describing geophysical models can be converted into integral equations. The end results are the integral formulas and integral equations that form the theoretical framework for practical applications. The details of mathematical analysis have been kept to a minimum. Numerical algorithms are discussed only in connection with some illustrative examples involving well-documented numerical modelling results. The reader is assu­ med to have a back...

  12. Mathematics applied to nuclear geophysics

    International Nuclear Information System (INIS)

    Pereira, E.B.; Nordemann, D.J.R.

    1987-01-01

    One of the powerful auxiliary to nuclear geophysics is the obtention and interpretation of the alpha and gamma radiation spectra. This work discuss, qualitative and quantitative, the lost information problem, motivated by the noise in the process of information codification. The decodification process must be suppield by the appropriate mathematical model on the measure system to recovery the information from nuclear source. (C.D.G.) [pt

  13. News Letter: European Geophysical Society

    Science.gov (United States)

    1998-03-01

    GLOWACKA, E.; ARELLANO, F. Land subsidence measurements at Cerro Prieto geothermal field (Baja California, Mexico ) using SAR interferometry 126...topics’ of ionospheric research, written by specialists in their respective fields . Useful as a textbook for students as well as for research...Geophysics thus have available mature, thoughtful reviews of recent developments in their own field , and they may be confident of keeping abreast in

  14. Geophysical investigations in the Veitsivaara area, Finland summary report

    International Nuclear Information System (INIS)

    Heikkinen, E.; Saksa, P.; Hinkkanen, H.

    1991-10-01

    Teollisuuden Voima Oy (TVO carries out site investigations in Finland for final disposal of nuclear high level waste during 1987-2000. Investigations by geological, geophysical, geohydrological and geochemical methods were carried out in the Veitsivaara area in 1987-90 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. Airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity. Airborne surveys were performed by magnetic, radiometric and two electromagnetic methods and ground investigations by VLF magnetic and resistivity, magnetic and impulse radar methods. Electromagnetic and seismic refraction surveys were used to locate crushed and fracture zones. The properties of weak electrical conductors, e.g. their depth dimensions, were studied by direct current resistivity measurements. The rock type distribution was studied by single-hole logging of susceptibility, natural γ-radiation and radiometric γ γ-density. Electrical and acoustic logging allowed water bearing fractures to be mapped and the results of water injection tests to be interpreted. Flow conditions in the boreholes were studied by both fluid logging and tube wave sounding

  15. The Role of Geophysics/Geology in the Environmental Discourse

    Science.gov (United States)

    Pfannkuch, H. O.

    2013-12-01

    Environmental problems are created by interaction between the Anthroposphere and Geosphere. Principles and laws governing behavior and interaction between them have to be fully understood to properly address environmental problems. A particular problem arises by inadequate communication between practitioners and/or decision makers in each sphere. A perfect analysis or solution in the Geosphere based solely on geophysical, geochemical principles will go nowhere if institutional, socio economic principles are ignored, or vice versa: no matter how well socio-economic relations are used in the Anthroposphere if they violate basic laws of physics . Two conceptual representations of the environment system are: Nöosphere with three domains: Physical, Institutional, Symbolic and their interactions. It is where environmental problems arise, decisions are made and implemented. The Physical Domain comprises physical, chemical, biological, geopsphere realities. Problems are treated by the scientific method. The Institutional Domain with economy, sociology, administration and political institutions, solves by negotiation (vote, ballot). The elements of the Symbolic Domain. spiritual, moral, religious, esthetic principles are revealed. All are intimately connected and interdependent. Activity in one affects the state of the others. A particularly strong and effective interactive relation exists between the Physical and the Institutional domains with regards to environmental problem definition, analysis and resolution. Hierarchic structure of interaction pyramid. Geosphere, Biosphere and Anthroposphere are open systems and are organized in successive levels forming a pyramid shape or aspect. The Geosphere forms the bottom level, the Anthroposphere the top. One fundamental attribute is that level (n) is limited by the restrictions obtaining in level (n-1), and conversely, level (n) represents the restrictions and limitations for level (n+1). In the environmental discourse this

  16. Final Scientific/Technical Report – DE-EE0002960 Recovery Act. Detachment faulting and Geothermal Resources - An Innovative Integrated Geological and Geophysical Investigation of Pearl Hot Spring, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, Daniel F. [Univ. of Texas, Austin, TX (United States)

    2015-11-30

    The Pearl Host Spring Geothermal Project funded by the DoE Geothermal Program was a joint academic (KU/UT & OU) and industry collaboration (Sierra and Ram Power) to investigate structural controls and the importance of low-angle normal faults on geothermal fluid flow through a multifaceted geological, geophysical, and geochemical investigation in west-central Nevada. The study clearly showed that the geothermal resources in Clayton Valley are controlled by the interplay between low-angle normal faults and active deformation related to the Walker Lane. The study not only identified potentially feasible blind geothermal resource plays in eastern Clayton Valley, but also provide a transportable template for exploration in the area of west-central Nevada and other regional and actively-deforming releasing fault bends. The study showed that deep-seated low-angle normal faults likely act as crustal scale permeability boundaries and could play an important role in geothermal circulation and funneling geothermal fluid into active fault zones. Not unique to this study, active deformation is viewed as an important gradient to rejuvenated fracture permeability aiding the long-term viability of blind geothermal resources. The technical approach for Phase I included the following components, (1) Structural and geological analysis of Pearl Hot Spring Resource, (2) (U-Th)/He thermochronometry and geothermometry, (3) detailed gravity data and modeling (plus some magnetic and resistivity), (4) Reflection and Refraction Seismic (Active Source), (5) Integration with existing and new geological/geophysical data, and (6) 3-D Earth Model, combining all data in an innovative approach combining classic work with new geochemical and geophysical methodology to detect blind geothermal resources in a cost-effective fashion.

  17. New perspectives on superparameterization for geophysical turbulence

    International Nuclear Information System (INIS)

    Majda, Andrew J.; Grooms, Ian

    2014-01-01

    This is a research expository paper regarding superparameterization, a class of multi-scale numerical methods designed to cope with the intermittent multi-scale effects of inhomogeneous geophysical turbulence where energy often inverse-cascades from the unresolved scales to the large scales through the effects of waves, jets, vortices, and latent heat release from moist processes. Original as well as sparse space–time superparameterization algorithms are discussed for the important case of moist atmospheric convection including the role of multi-scale asymptotic methods in providing self-consistent constraints on superparameterization algorithms and related deterministic and stochastic multi-cloud parameterizations. Test models for the statistical numerical analysis of superparameterization algorithms are discussed both to elucidate the performance of the basic algorithms and to test their potential role in efficient multi-scale data assimilation. The very recent development of grid-free seamless stochastic superparameterization methods for geophysical turbulence appropriate for “eddy-permitting” mesoscale ocean turbulence is presented here including a general formulation and illustrative applications to two-layer quasigeostrophic turbulence, and another difficult test case involving one-dimensional models of dispersive wave turbulence. This last test case has randomly generated solitons as coherent structures which collapse and radiate wave energy back to the larger scales, resulting in strong direct and inverse turbulent energy cascades

  18. Geochemical engineering reference manual

    Energy Technology Data Exchange (ETDEWEB)

    Owen, L.B.; Michels, D.E.

    1984-01-01

    The following topics are included in this manual: physical and chemical properties of geothermal brine and steam, scale and solids control, processing spent brine for reinjection, control of noncondensable gas emissions, and goethermal mineral recovery. (MHR)

  19. The teaching of geophysics in Latin America: An updated assessment

    Science.gov (United States)

    Valencio, Daniel A.; Schneider, Otto

    The situation of geophysics in developing countries has been the subject of discussions and analysis by diverse international organizations. It was also discussed in some articles in Eos [e.g., Lomnitz, 1982; Urrutia Fucugauchi, 1982; Bolt, 1982]. We have been requested to contribute a current evaluation of the problem, with particular reference to geophysical education in Latin America.In the following report on specialized training of geophysicists in Latin American countries, we consider the “exact earth sciences” in the broader sense, i.e., the mathematical and physical (and, to a certain extent, chemical) aspects of the planet earth as a whole, including its fluid portions, as opposed to the more restricted concept of just solid earth geophysics. In other words, our inquiry follows the scope of both AGU and the International Union of Geodesy and Geophysics (IUGG), so geodesy, although not explicitly covered, will still be mentioned occasionally. We will also consider the applied branches, especially exploration geophysics, since these areas furnish powerful motivation for fostering our sciences, both in the governmental circles of developing countries and among the young people looking for a promising professional future.

  20. Geophysics: The Earth in Space. A Guide for High School Students.

    Science.gov (United States)

    American Geophysical Union, Washington, DC.

    Geophysics is the application of physics, chemistry, and mathematics to the problems and processes of the earth, from its innermost core to its outermost environs in space. Fields within geophysics include the atmospheric sciences; geodesy; geomagnetism and paleomagnetism; hydrology; oceanography; planetology; seismology; solar-planetary…

  1. The Nirex Sellafield site investigation: the role of geophysical interpretation

    International Nuclear Information System (INIS)

    Muir Wood, R.; Woo, G.; MacMillan, G.

    1992-01-01

    This report reviews the methods by which geophysical data are interpreted, and used to characterize the 3-D geology of a site for potential storage of radioactive waste. The report focuses on the NIREX site investigation at Sellafield, for which geophysical observations provide a significant component of the structural geological understanding. In outlining the basic technical principles of seismic data processing and interpretation, and borehole logging, an attempt has been made to identify errors, uncertainties, and the implicit use of expert judgement. To enhance the reliability of a radiological probabilistic risk assessment, recommendations are proposed for independent use of the primary NIREX geophysical site investigation data in characterizing the site geology. These recommendations include quantitative procedures for undertaking an uncertainty audit using a combination of statistical analysis and expert judgement. (author)

  2. Geophysical Limitations on the Habitable Zone

    Science.gov (United States)

    Noack, L.; Van Hoolst, T.

    2015-10-01

    Planets are typically classified as potentially life-bearing planets (i.e. habitable planets) if they are rocky planets and if a liquid (e.g. water) could exist at the surface. The latter depends on several factors, like for example the amount of available solar energy, greenhouse effects in the atmosphere and an efficient CO2-cycle. However, the definition of the habitable zone should be updated to include possible geophy-sical constraints, that could potentially influence the CO2-cycle. Planets like Mars without plate tectonics and no or only limited volcanic events can only be considered to be habitable at the inner boundary of the habitable zone, since the greenhouse effect needed to ensure liquid surface water farther away from the sun is strongly reduced. We investigate how these geophysical processes depend on the mass and interior structure of terrestrial planets. We find that plate tectonics, if it occurs, always leads to sufficient volcanic outgassing and therefore greenhouse effect needed for the outer boundary of the habitable zone (several tens of bar CO2). One-plate planets, however, may suffer strong volcanic limitations if their mass and/or iron content exceeds a critical value, reducing their possible surface habitability.

  3. Teaching Computational Geophysics Classes using Active Learning Techniques

    Science.gov (United States)

    Keers, H.; Rondenay, S.; Harlap, Y.; Nordmo, I.

    2016-12-01

    We give an overview of our experience in teaching two computational geophysics classes at the undergraduate level. In particular we describe The first class is for most students the first programming class and assumes that the students have had an introductory course in geophysics. In this class the students are introduced to basic Matlab skills: use of variables, basic array and matrix definition and manipulation, basic statistics, 1D integration, plotting of lines and surfaces, making of .m files and basic debugging techniques. All of these concepts are applied to elementary but important concepts in earthquake and exploration geophysics (including epicentre location, computation of travel time curves for simple layered media plotting of 1D and 2D velocity models etc.). It is important to integrate the geophysics with the programming concepts: we found that this enhances students' understanding. Moreover, as this is a 3 year Bachelor program, and this class is taught in the 2nd semester, there is little time for a class that focusses on only programming. In the second class, which is optional and can be taken in the 4th or 6th semester, but often is also taken by Master students we extend the Matlab programming to include signal processing and ordinary and partial differential equations, again with emphasis on geophysics (such as ray tracing and solving the acoustic wave equation). This class also contains a project in which the students have to write a brief paper on a topic in computational geophysics, preferably with programming examples. When teaching these classes it was found that active learning techniques, in which the students actively participate in the class, either individually, in pairs or in groups, are indispensable. We give a brief overview of the various activities that we have developed when teaching theses classes.

  4. Geophysical Study of Lithologies Attributes At Isihor Village, Edo ...

    African Journals Online (AJOL)

    These attributes include depth, thickness of lithologies or rock types beneath the sea level or earth's surface. Geophysical prospect of lithologies in this studied area is vital for many economic and environmental reasons for examples a large portion of the world's fossil fuels such as oil, gas and coal are found in stratified ...

  5. Geophysical investigation of the causes of highway failures in Niger ...

    African Journals Online (AJOL)

    It is hereby recommended that the clay zones be replaced with more competent sands. The road should be built to specification with high quality materials and also drainage be included in the ongoing expansion and construction work. Keywords: Highway, Geophysical Survey, Failed portion, Stable portion, Geological ...

  6. Geophysical Study of Aquifer Properties at Isihor Village of Edo ...

    African Journals Online (AJOL)

    Ten (10) vertical electrical sounding (VES) (uniformly distributed) based on electrical resistivity method was carried out in a geophysical survey in order to study aquifer properties. These properties include depth, thickness and nature of soil above the aquifer. Schlumberger array of VES was conducted in Isihor Village and ...

  7. Marine Geology and Geophysics Field Course Offered by The University of Texas Institute for Geophysics

    Science.gov (United States)

    Duncan, D.; Davis, M. B.; Allison, M. A.; Gulick, S. P.; Goff, J. A.; Saustrup, S.

    2012-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers an intensive three-week marine geology and geophysics field course during the spring-summer intersession. Now in year six, the course provides hands-on instruction and training for graduate and upper-level undergraduate students in data acquisition, processing, interpretation, and visualization. Techniques covered include high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples (e.g., core description, grain size analysis, x-radiography, etc.). Students participate in an initial period of classroom instruction designed to communicate geological context of the field area (which changes each year) along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. Our field sites at Port Aransas and Galveston, Texas, and Grand Isle, Louisiana, have provided ideal locations for students to investigate coastal and sedimentary processes of the Gulf Coast and continental shelf through application of geophysical techniques. In the field, students rotate between two research vessels: one vessel, the 22' aluminum-hulled R/V Lake Itasca, owned and operated by UTIG, is used principally for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA's R/V Manta or the R/V Acadiana, operated by the Louisiana Universities Marine Consortium, and is used primarily for high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, gravity coring, and vibrocoring. While at sea, students assist with survey design, learn instrumentation set up, acquisition parameters, data quality control, and safe instrument deployment and retrieval. In teams of three, students work in onshore field labs preparing sediment samples for

  8. Alternative geochemical barrier materials

    International Nuclear Information System (INIS)

    1991-07-01

    Previous investigations of the effects of neutralization and reduction on uranium mill tailings pore fluids by the Technical Support Contractor indicated that arsenic, selenium, and molybdenum continue to remain in solution in all but reducing conditions. These hazardous constituents are present in groundwaters as oxyanions and, therefore, are not expected to be removed by adsorption into clays and most other soil constituents. It was decided to investigate the attenuation capacity of two commonly available crystalline iron oxides, taconite and scoria, and a zeolite, a network aluminosilicate with a cage structure. Columns of the candidate materials were exposed to solutions of individual constituents, including arsenic, molybdenum, selenium, and, uranium, and to the spiked tailings pore fluid from the Bodo Canyon disposal cell near Durango, Colorado. In addition to the single material columns, a homogeneous blend of the three materials and layers of the materials were exposed to spiked tailings pore fluids. The results of these experiments indicate that with the exception of molybdenum, the constituents of concern are attenuated by the taconite; however, they are not sufficiently attenuated to meet the groundwater protection standards applicable to the UMTRA Project. Therefore, the candidate barrier materials did not prove to be useful to the UMTRA Project for the cleanup of groundwaters

  9. Forensic Analysis using Geological and Geochemical Techniques

    Science.gov (United States)

    Hoogewerff, J.

    2009-04-01

    Due to the globalisation of legal (and illegal) trade there is an increasing demand for techniques which can verify the geographical origin and transfer routes of many legal and illegal commodities and products. Although geological techniques have been used in forensic investigations since the emergence of forensics as a science in the late eighteen hundreds, the last decade has seen a marked increase in geo-scientists initiating concept studies using the latest analytical techniques, including studying natural abundance isotope variations, micro analysis with laser ablation ICPMS and geochemical mapping. Most of the concept studies have shown a good potential but uptake by the law enforcement and legal community has been limited due to concerns about the admissibility of the new methods. As an introduction to the UGU2009 session "Forensic Provenancing using Geological and Geochemical Techniques" I will give an overview of the state of the art of forensic geology and the issues that concern the admissibility of geological forensic evidence. I will use examples from the NITECRIME and FIRMS networks, the EU TRACE project and other projects and literature to illustrate the important issues at hand.

  10. Institute of Geophysics, Planetary Physics, and Signatures

    Data.gov (United States)

    Federal Laboratory Consortium — The Institute of Geophysics, Planetary Physics, and Signatures at Los Alamos National Laboratory is committed to promoting and supporting high quality, cutting-edge...

  11. Digital Underground (Shh. It's really Applied Geophysics!)

    Science.gov (United States)

    McAdoo, B. G.

    2003-12-01

    Digital Underground (Geology/Physics 241) at Vassar College is an applied geophysics course designed for a liberal arts curriculum, and has nothing to do with Shock G and Tupac Shakur. Applied geophysics courses have a history of using geophysical methods on environmental contamination-type applications (underground storage tanks, leach fields, etc.). Inspired in large part by the Keck Geology Consortium project run by Franklin and Marshall College geophysicist (Robert Sternberg) and archaeologist (James Delle) in an old slave village in Jamaica in 1999, this class examines the history of slavery in New York's Hudson Valley region by way of its forgotten African-American graveyards. This multidisciplinary approach to an issue draws students from across the curriculum- we have had our compliments of geologists and physicists, along with students from sociology, environmental studies, history, and Africana studies. The name of the class and content are designed to attract a non-traditional student of geophysics.- The project-based nature of the class appeals to student yearning for an out-of-classroom experience. The uncontrolled nature of the class demonstrates the complications that occur in real-word situations. The class has in the past broken itself into two teams- a surveying team and an archival research team. Archival research is done (usually by the social scientists in the class) to add a human dimension to the geophysical. The surveying equipment used in delineating these forgotten graveyards includes a Total Station surveyor, an electrical resistivity meter, a magnetometer, and a ground penetrating radar. All students must have a rudimentary understanding of the physics behind the equipment (to the level of where they can explain it to the general public), and the methods used by those studying the archives. This is a project-based class, where the instructor acts as a project manager, and the students make the decisions regarding the survey itself. Every

  12. Numerical modeling of geochemical variations caused by crustal relamination

    NARCIS (Netherlands)

    Vogt, Katharina|info:eu-repo/dai/nl/370618947; Castro, Antonio; Gerya, Taras

    2013-01-01

    Geochemical consequences of composite diapirs formed in subduction zones have been studied using a thermomechanical numerical model of an ocean-continent subduction zone. This model includes dehydration of subducted crust, aqueous fluid transport, partial melting, and melt emplacement. Subduction of

  13. The Dynamics of Oceanic Transform Faults: Constraints from Geophysical, Geochemical and Geodynamical Modeling

    Science.gov (United States)

    2008-06-01

    magma chain- of 2,550 kg m -3 of the mantle where temperatures are <Sl5t0 -(2 Iter riLav exist beostth the enitire segnent and feed dvkcN front the...best explain the gravity-derived crustal thickness variations observed at the Siqueiros transform. Furthermore, a mantle potential temperature of...excess magma supply and increasing crustal production within the transform fault domain. These findings directly contradict the classic models of crustal

  14. Open Access to Geophysical Data

    Science.gov (United States)

    Sergeyeva, Nataliya A.; Zabarinskaya, Ludmila P.

    2017-04-01

    Russian World Data Centers for Solar-Terrestrial Physics & Solid Earth Physics hosted by the Geophysical Center of the Russian Academy of Sciences are the Regular Members of the ICSU-World Data System. Guided by the principles of the WDS Constitution and WDS Data Sharing Principles, the WDCs provide full and open access to data, long-term data stewardship, compliance with agreed-upon data standards and conventions, and mechanisms to facilitate and improve access to data. Historical and current geophysical data on different media, in the form of digital data sets, analog records, collections of maps, descriptions are stored and collected in the Centers. The WDCs regularly fill up repositories and database with new data, support them up to date. Now the WDCs focus on four new projects, aimed at increase of data available in network by retrospective data collection and digital preservation of data; creation of a modern system of registration and publication of data with digital object identifier (DOI) assignment, and promotion of data citation culture; creation of databases instead of file system for more convenient access to data; participation in the WDS Metadata Catalogue and Data Portal by creating of metadata for information resources of WDCs.

  15. Geophysical characterization of subsurface barriers

    International Nuclear Information System (INIS)

    Borns, D.J.

    1995-08-01

    An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier

  16. SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    RUCKER DF; MYERS DA

    2011-10-04

    This report documents the evolution of the surface geophysical exploration (SGE) program and highlights some of the most recent successes in imaging conductive targets related to past leaks within and around Hanford's tank farms. While it is noted that the SGE program consists of multiple geophysical techniques designed to (1) locate near surface infrastructure that may interfere with (2) subsurface plume mapping, the report will focus primarily on electrical resistivity acquisition and processing for plume mapping. Due to the interferences from the near surface piping network, tanks, fences, wells, etc., the results of the three-dimensional (3D) reconstruction of electrical resistivity was more representative of metal than the high ionic strength plumes. Since the first deployment, the focus of the SGE program has been to acquire and model the best electrical resistivity data that minimizes the influence of buried metal objects. Toward that goal, two significant advances have occurred: (1) using the infrastructure directly in the acquisition campaign and (2) placement of electrodes beneath the infrastructure. The direct use of infrastructure was successfully demonstrated at T farm by using wells as long electrodes (Rucker et al., 2010, 'Electrical-Resistivity Characterization of an Industrial Site Using Long Electrodes'). While the method was capable of finding targets related to past releases, a loss of vertical resolution was the trade-off. The burying of electrodes below the infrastructure helped to increase the vertical resolution, as long as a sufficient number of electrodes are available for the acquisition campaign.

  17. Surface Geophysical Exploration - Compendium Document

    International Nuclear Information System (INIS)

    Rucker, D.F.; Myers, D.A.

    2011-01-01

    This report documents the evolution of the surface geophysical exploration (SGE) program and highlights some of the most recent successes in imaging conductive targets related to past leaks within and around Hanford's tank farms. While it is noted that the SGE program consists of multiple geophysical techniques designed to (1) locate near surface infrastructure that may interfere with (2) subsurface plume mapping, the report will focus primarily on electrical resistivity acquisition and processing for plume mapping. Due to the interferences from the near surface piping network, tanks, fences, wells, etc., the results of the three-dimensional (3D) reconstruction of electrical resistivity was more representative of metal than the high ionic strength plumes. Since the first deployment, the focus of the SGE program has been to acquire and model the best electrical resistivity data that minimizes the influence of buried metal objects. Toward that goal, two significant advances have occurred: (1) using the infrastructure directly in the acquisition campaign and (2) placement of electrodes beneath the infrastructure. The direct use of infrastructure was successfully demonstrated at T farm by using wells as long electrodes (Rucker et al., 2010, 'Electrical-Resistivity Characterization of an Industrial Site Using Long Electrodes'). While the method was capable of finding targets related to past releases, a loss of vertical resolution was the trade-off. The burying of electrodes below the infrastructure helped to increase the vertical resolution, as long as a sufficient number of electrodes are available for the acquisition campaign.

  18. Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.; Ajo-Franklin, J.B.; Spycher, N.; Hubbard, S.S.; Zhang, G.; Williams, K.H.; Taylor, J.; Fujita, Y.; Smith, R.

    2011-07-15

    Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic) sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT), and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes promoted through NH{sub 4}{sup

  19. Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation

    Directory of Open Access Journals (Sweden)

    Taylor Joanna

    2011-09-01

    Full Text Available Abstract Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT, and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes

  20. Field Analytical Techniques for Geochemical Surveys

    OpenAIRE

    Lemière, Bruno

    2015-01-01

    International audience; Obtaining geochemical results in the field has been a persistent dream for exploration geologists in the last century, and a few practical geochemical? tests were developed, but shipping samples to faraway labs and waiting weeks for results was the rule. This remained a dream until around 1990, when technology developments of portable instruments allowed on-site measurement of the first key metals in solids. This development progressed rapidly and by 2010, most geochem...

  1. Applied Geophysics Opportunities in the Petroleum Industry

    Science.gov (United States)

    Olgaard, D. L.; Tikku, A.; Roberts, J. C.; Martinez, A.

    2012-12-01

    Meeting the increasing global demand for energy over the next several decades presents daunting challenges to engineers and scientists, including geoscientists of all disciplines. Many opportunities exist for geophysicists to find and produce oil and gas in a safe, environmentally responsible and affordable manner. Successful oil and gas exploration involves a 'Plates to Pores' approach that integrates multi-scale data from satellites, marine and land seismic and non-seismic field surveys, lab experiments, and even electron microscopy. The petroleum industry is at the forefront of using high performance computing to develop innovative methods to process and analyze large volumes of seismic data and perform realistic numerical modeling, such as finite element fluid flow and rock deformation simulations. Challenging and rewarding jobs in exploration, production and research exist for students with BS/BA, MS and PhD degrees. Geophysics students interested in careers in the petroleum industry should have a broad foundation in science, math and fundamental geosciences at the BS/BA level, as well as mastery of the scientific method, usually gained through thesis work at MS and PhD levels. Field geology or geophysics experience is also valuable. Other personal attributes typical for geoscientists to be successful in industry include a passion for solving complex geoscience problems, the flexibility to work on a variety of assignments throughout a career and skills such as teamwork, communication, integration and leadership. In this presentation we will give examples of research, exploration and production opportunities for geophysicists in petroleum companies and compare and contrast careers in academia vs. industry.

  2. Soil Iodine Determination in Deccan Syneclise, India: Implications for Near Surface Geochemical Hydrocarbon Prospecting

    International Nuclear Information System (INIS)

    Mani, Devleena; Kumar, T. Satish; Rasheed, M. A.; Patil, D. J.; Dayal, A. M.; Rao, T. Gnaneshwar; Balaram, V.

    2011-01-01

    The association of iodine with organic matter in sedimentary basins is well documented. High iodine concentration in soils overlying oil and gas fields and areas with hydrocarbon microseepage has been observed and used as a geochemical exploratory tool for hydrocarbons in a few studies. In this study, we measure iodine concentration in soil samples collected from parts of Deccan Syneclise in the west central India to investigate its potential application as a geochemical indicator for hydrocarbons. The Deccan Syneclise consists of rifted depositional sites with Gondwana–Mesozoic sediments up to 3.5 km concealed under the Deccan Traps and is considered prospective for hydrocarbons. The concentration of iodine in soil samples is determined using ICP-MS and the values range between 1.1 and 19.3 ppm. High iodine values are characteristic of the northern part of the sampled region. The total organic carbon (TOC) content of the soil samples range between 0.1 and 1.3%. The TOC correlates poorly with the soil iodine (r 2 < 1), indicating a lack of association of iodine with the surficial organic matter and the possibility of interaction between the seeping hydrocarbons and soil iodine. Further, the distribution pattern of iodine compares well with two surface geochemical indicators: the adsorbed light gaseous hydrocarbons (methane through butane) and the propane-oxidizing bacterial populations in the soil. The integration of geochemical observations show the occurrence of elevated values in the northern part of the study area, which is also coincident with the presence of exposed dyke swarms that probably serve as conduits for hydrocarbon microseepage. The corroboration of iodine with existing geological, geophysical, and geochemical data suggests its efficacy as one of the potential tool in surface geochemical exploration of hydrocarbons. Our study supports Deccan Syneclise to be promising in terms of its hydrocarbon prospects.

  3. A geochemical atlas of North Carolina, USA

    Science.gov (United States)

    Reid, J.C.

    1993-01-01

    A geochemical atlas of North Carolina, U.S.A., was prepared using National Uranium Resource Evaluation (NURE) stream-sediment data. Before termination of the NURE program, sampling of nearly the entire state (48,666 square miles of land area) was completed and geochemical analyses were obtained. The NURE data are applicable to mineral exploration, agriculture, waste disposal siting issues, health, and environmental studies. Applications in state government include resource surveys to assist mineral exploration by identifying geochemical anomalies and areas of mineralization. Agriculture seeks to identify areas with favorable (or unfavorable) conditions for plant growth, disease, and crop productivity. Trace elements such as cobalt, copper, chromium, iron, manganese, zinc, and molybdenum must be present within narrow ranges in soils for optimum growth and productivity. Trace elements as a contributing factor to disease are of concern to health professionals. Industry can use pH and conductivity data for water samples to site facilities which require specific water quality. The North Carolina NURE database consists of stream-sediment samples, groundwater samples, and stream-water analyses. The statewide database consists of 6,744 stream-sediment sites, 5,778 groundwater sample sites, and 295 stream-water sites. Neutron activation analyses were provided for U, Br, Cl, F, Mn, Na, Al, V, Dy in groundwater and stream water, and for U, Th, Hf, Ce, Fe, Mn, Na, Sc, Ti, V, Al, Dy, Eu, La, Sm, Yb, and Lu in stream sediments. Supplemental analyses by other techniques were reported on U (extractable), Ag, As, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, W, Y, and Zn for 4,619 stream-sediment samples. A small subset of 334 stream samples was analyzed for gold. The goal of the atlas was to make available the statewide NURE data with minimal interpretation to enable prospective users to modify and manipulate the data for their end use. The atlas provides only

  4. Geophysical subsurface imaging and interface identification.

    Energy Technology Data Exchange (ETDEWEB)

    Pendley, Kevin; Bochev, Pavel Blagoveston; Day, David Minot; Robinson, Allen Conrad; Weiss, Chester Joseph

    2005-09-01

    Electromagnetic induction is a classic geophysical exploration method designed for subsurface characterization--in particular, sensing the presence of geologic heterogeneities and fluids such as groundwater and hydrocarbons. Several approaches to the computational problems associated with predicting and interpreting electromagnetic phenomena in and around the earth are addressed herein. Publications resulting from the project include [31]. To obtain accurate and physically meaningful numerical simulations of natural phenomena, computational algorithms should operate in discrete settings that reflect the structure of governing mathematical models. In section 2, the extension of algebraic multigrid methods for the time domain eddy current equations to the frequency domain problem is discussed. Software was developed and is available in Trilinos ML package. In section 3 we consider finite element approximations of De Rham's complex. We describe how to develop a family of finite element spaces that forms an exact sequence on hexahedral grids. The ensuing family of non-affine finite elements is called a van Welij complex, after the work [37] of van Welij who first proposed a general method for developing tangentially and normally continuous vector fields on hexahedral elements. The use of this complex is illustrated for the eddy current equations and a conservation law problem. Software was developed and is available in the Ptenos finite element package. The more popular methods of geophysical inversion seek solutions to an unconstrained optimization problem by imposing stabilizing constraints in the form of smoothing operators on some enormous set of model parameters (i.e. ''over-parametrize and regularize''). In contrast we investigate an alternative approach whereby sharp jumps in material properties are preserved in the solution by choosing as model parameters a modest set of variables which describe an interface between adjacent regions in

  5. Effect of source integration on the geochemical fluxes from springs

    International Nuclear Information System (INIS)

    Frisbee, Marty D.; Phillips, Fred M.; White, Art F.; Campbell, Andrew R.; Liu, Fengjing

    2013-01-01

    Geochemical fluxes from watersheds are typically defined using mass-balance methods that essentially lump all weathering processes operative in a watershed into a single flux of solute mass measured in streamflow at the watershed outlet. However, it is important that we understand how weathering processes in different hydrological zones of a watershed (i.e., surface, unsaturated, and saturated zones) contribute to the total geochemical flux from the watershed. This capability will improve understanding of how geochemical fluxes from these different zones may change in response to climate change. Here, the geochemical flux from weathering processes occurring solely in the saturated zone is investigated. This task, however, remains exceedingly difficult due to the sparsity of subsurface sampling points, especially in large, remote, and/or undeveloped watersheds. In such cases, springflow is often assumed to be a proxy for groundwater (defined as water residing in fully saturated geologic formations). However, springflow generation may integrate different sources of water including, but not limited to, groundwater. The authors’ hypothesis is that long-term estimates of geochemical fluxes from groundwater using springflow proxies will be too large due to the integrative nature of springflow generation. Two conceptual models of springflow generation are tested using endmember mixing analyses (EMMA) on observations of spring chemistries and stable isotopic compositions in a large alpine watershed in the San Juan Mountains of southwestern Colorado. In the “total springflow” conceptual model, springflow is assumed to be 100% groundwater. In the “fractional springflow” conceptual model, springflow is assumed to be an integration of different sources of water (e.g., groundwater, unsaturated flow, preferential flow in the soil, etc.) and groundwater is only a fractional component. The results indicate that groundwater contributions in springflow range from 2% to 100

  6. Agricultural Geophysics: Past, present, and future

    Science.gov (United States)

    Geophysical methods are becoming an increasingly valuable tool for agricultural applications. Agricultural geophysics investigations are commonly (although certainly not always) focused on delineating small- and/or large-scale objects/features within the soil profile (~ 0 to 2 m depth) over very lar...

  7. Symmetries in geology and geophysics.

    Science.gov (United States)

    Turcotte, D L; Newman, W I

    1996-12-10

    Symmetries have played an important role in a variety of problems in geology and geophysics. A large fraction of studies in mineralogy are devoted to the symmetry properties of crystals. In this paper, however, the emphasis will be on scale-invariant (fractal) symmetries. The earth's topography is an example of both statistically self-similar and self-affine fractals. Landforms are also associated with drainage networks, which are statistical fractal trees. A universal feature of drainage networks and other growth networks is side branching. Deterministic space-filling networks with side-branching symmetries are illustrated. It is shown that naturally occurring drainage networks have symmetries similar to diffusion-limited aggregation clusters.

  8. Numerical simulation in applied geophysics

    CERN Document Server

    Santos, Juan Enrique

    2016-01-01

    This book presents the theory of waves propagation in a fluid-saturated porous medium (a Biot medium) and its application in Applied Geophysics. In particular, a derivation of absorbing boundary conditions in viscoelastic and poroelastic media is presented, which later is employed in the applications. The partial differential equations describing the propagation of waves in Biot media are solved using the Finite Element Method (FEM). Waves propagating in a Biot medium suffer attenuation and dispersion effects. In particular the fast compressional and shear waves are converted to slow diffusion-type waves at mesoscopic-scale heterogeneities (on the order of centimeters), effect usually occurring in the seismic range of frequencies. In some cases, a Biot medium presents a dense set of fractures oriented in preference directions. When the average distance between fractures is much smaller than the wavelengths of the travelling fast compressional and shear waves, the medium behaves as an effective viscoelastic an...

  9. Strainmeters and tiltmeters in geophysics

    Science.gov (United States)

    Goulty, N. R.

    1976-01-01

    Several types of sensitive strainmeters and tiltmeters have been developed, and it is now becoming clear which geophysical applications are most suitable for these instruments. In general, strainmeters and tiltmeters are used for observing ground deformation at periods of minutes to days. Small-scale lateral inhomogeneities at the instrument sites distort signals by a few percent, although the effects of large structures can be calculated. In earth tide work these lateral inhomogeneities and unknown ocean loading signals prevent accurate values of the regional tide from being obtained. This limits tidal investigations to looking for temporal variations, possibly associated with pre-earthquake dilatancy, and spatial variations caused by gross elasticity contrasts in the local geological structure. Strainmeters and tiltmeters are well suited for observing long-period seismic waves, seismic slip events on faults and volcano tumescence, where small site-induced distortions in the measured signals are seldom important.

  10. Agricultural geophysics: Past/present accomplishments and future advancements

    Science.gov (United States)

    Geophysical methods have become an increasingly valuable tool for application within a variety of agroecosystems. Agricultural geophysics measurements are obtained at a wide range of scales and often exhibit significant variability both temporally and spatially. The three geophysical methods predomi...

  11. Status report on geochemical modelling

    International Nuclear Information System (INIS)

    Read, D.

    1991-12-01

    This report describes the findings of a review undertaken on behalf of the project management group of the programme 'Endlagersicherheit in der Nachbetriebsphase' based at GSF-IfT (Forschungszentrum fuer Umwelt und Gesundheit - Institut fuer Tieflagerung) to establish the current status of research into the simulation of geochemical processes relevant to radiological assessment. The review is intended to contribute to Stage 1 of a strategy formulated to enhance the use of geochemical models in Germany. Emphasis has been placed on processes deemed to be of greatest relevance to performance assessment for a HLW-repository in a salt dome principally, speciation-solubility in high salinity solutions, complexation by natural organics and generation-transport of colloids. For each of these and other topics covered, a summary is given of fundamental concepts, theoretical representations and their limitations, highlighting, where appropriate, the advantages and disadvantages of alternative approaches. The availability of data to quantify any given representation is addressed, taking into account the need for information at elevated temperatures and pressures. Mass transfer is considered in terms of aqueous, particulate and gas-mediated transport, respectively. (orig.) [de

  12. Detecting Underground Mine Voids Using Complex Geophysical Techniques

    Science.gov (United States)

    Kaminski, V. F.; Harbert, W. P.; Hammack, R. W.; Ackman, T. E.

    2006-12-01

    In July 2006, the National Energy Technology Laboratory in collaboration with Department of Geology and Planetary Science, University of Pittsburgh conducted complex ground geophysical surveys of an area known to be underlain by shallow coal mines. Geophysical methods including electromagnetic induction, DC resistivity and seismic reflection were conducted. The purpose of these surveys was to: 1) verify underground mine voids based on a century-old mine map that showed subsurface mine workings georeferenced to match with present location of geophysical test-site located on the territory of Bruceton research center in Pittsburgh, PA, 2) deliniate mine workings that may be potentially filled with electrically conductive water filtrate emerging from adjacent groundwater collectors and 3) establish an equipment calibration site for geophysical instruments. Data from electromagnetic and resistivity surveys were further processed and inverted using EM1DFM, EMIGMA or Earthimager 2D capablilities in order to generate conductivity/depth images. Anomaly maps were generated, that revealed the locations of potential mine openings.

  13. Innovative Navigation Systems to Support Digital Geophysical Mapping, ESTCP #200129, Phase II Demonstrations

    National Research Council Canada - National Science Library

    Simms, Janet; Carin, Larry

    2004-01-01

    ... and subsurface seeded geophysical anomalies. The technologies included a commercially available RTK GPS with acoustic navigation, a Robotic Total Station laser-based system, a DGPS integrated with an improved low cost Inertial Navigation System...

  14. Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes 5 km gridded data from the Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA) conducted during the 2004-2005...

  15. Geodetic and geophysical observations in Antarctica an overview in the IPY perspective

    CERN Document Server

    Capra, Alessandro

    2008-01-01

    This book is a collection of papers on various aspects of the geodetic and geophysical investigation and observation techniques. It includes material from the Arctic and Antarctica, as well as covering work from both temporary and permanent observatories.

  16. Validation of the WATEQ4 geochemical model for uranium

    International Nuclear Information System (INIS)

    Krupka, K.M.; Jenne, E.A.; Deutsch, W.J.

    1983-09-01

    As part of the Geochemical Modeling and Nuclide/Rock/Groundwater Interactions Studies Program, a study was conducted to partially validate the WATEQ4 aqueous speciation-solubility geochemical model for uranium. The solubility controls determined with the WATEQ4 geochemical model were in excellent agreement with those laboratory studies in which the solids schoepite [UO 2 (OH) 2 . H 2 O], UO 2 (OH) 2 , and rutherfordine ((UO 2 CO 3 ) were identified as actual solubility controls for uranium. The results of modeling solution analyses from laboratory studies of uranyl phosphate solids, however, identified possible errors in the characterization of solids in the original solubility experiments. As part of this study, significant deficiencies in the WATEQ4 thermodynamic data base for uranium solutes and solids were corrected. Revisions included recalculation of selected uranium reactions. Additionally, thermodynamic data for the hydroxyl complexes of U(VI), including anionic (VI) species, were evaluated (to the extent permitted by the available data). Vanadium reactions were also added to the thermodynamic data base because uranium-vanadium solids can exist in natural ground-water systems. This study is only a partial validation of the WATEQ4 geochemical model because the available laboratory solubility studies do not cover the range of solid phases, alkaline pH values, and concentrations of inorganic complexing ligands needed to evaluate the potential solubility of uranium in ground waters associated with various proposed nuclear waste repositories. Further validation of this or other geochemical models for uranium will require careful determinations of uraninite solubility over the pH range of 7 to 10 under highly reducing conditions and of uranyl hydroxide and phosphate solubilities over the pH range of 7 to 10 under oxygenated conditions

  17. Potential application of radiogenic isotopes and geophysical methods to understand the hydrothermal dystem of the Upper Geyser Basin, Yellowstone National Park

    Science.gov (United States)

    Paces, James B.; Long, Andrew J.; Koth, Karl R.

    2015-01-01

    Numerous geochemical and geophysical studies have been conducted at Yellowstone National Park to better understand the hydrogeologic processes supporting the thermal features of the Park. This report provides the first 87Sr/86Sr and 234U/238U data for thermal water from the Upper Geyser Basin (UGB) intended to evaluate whether heavy radiogenic isotopes might provide insight to sources of groundwater supply and how they interact over time and space. In addition, this report summarizes previous geophysical studies made at Yellowstone National Park and provides suggestions for applying non-invasive ground and airborne studies to better understand groundwater flow in the subsurface of the UGB. Multiple samples from Old Faithful, Aurum, Grand, Oblong, and Daisy geysers characterized previously for major-ion concentrations and isotopes of water (δ2H, δ18O, and 3H) were analyzed for Sr and U isotopes. Concentrations of dissolved Sr and U are low (4.3–128 ng g-1 Sr and 0.026–0.0008 ng g-1 U); consequently only 87Sr/86Sr data are reported for most samples. Values of 87Sr/86Sr for most geysers remained uniform between April and September 2007, but show large increases in all five geysers between late October 2007 and early April, 2008. By late summer of 2008, 87Sr/86Sr values returned to values similar to those observed a year earlier. Similar patterns are not present in major-ion data measured on the same samples. Furthermore, large geochemical differences documented between geysers are not observed in 87Sr/86Sr data, although smaller differences between sites may be present. Sr-isotope data are consistent with a stratified hydrologic system where water erupted in spring and summer of 2007 and summer of 2008 equilibrated with local intracaldera rhyolite flows at shallower depths. Water erupted between October 2007 and April 2008 includes greater amounts of groundwater that circulated deep enough to acquire a radiogenic 87Sr/86Sr, most likely from Archean basement

  18. GEOPHYSICAL CONTRIBUTION TO EVALUATE THE HYDROTHERMAL POTENTIALITY IN EGYPT: CASE STUDY: HAMMAM FARAUN AND ABU SWIERA, SINAI, EGYPT

    Directory of Open Access Journals (Sweden)

    Taha Ayman I

    2010-06-01

    Full Text Available The geothermal potentiality in Egypt has a minor significance in the aspects of the Egyptians life, while the hydraulic and hydrocarbonresources are more convenient. However, some other applications for the geothermal activity such as direct warming, pools, and physiotherapy make the research for geothermal as requested. In the present work, two locations with rather good geothermal potentiality will be studied; these are HammamFaraun and Abu Swiera (water temperature is about 70 °C; at Sinai Peninsula.
    The contribution of the geophysical techniques to evaluate such potentiality could be considered, as its capability to identifythe reservoir characteristics and its implementation is acceptable. Therefore, a geophysical survey program has been conductedin terms of seventeen vertical electrical soundings (VES and two wide profiles of Control Source Electromagnetic (CSEM forward step at HammamFaraun and two wide profiles of CSEM at Abu Swiera. The geophysical techniques yield information on the spatial distribution of electrical conductivity, which is the most sensitive parameter to fluids in the rocks. 
    The analysis of the geophysical data, together with the field and geochemical studies lead to the conclusion that, the thermalwater in the subsurface formations might be considered as the preferred cause of the high conductivity in the subsurface on/close to the boarder of tectonically active regions, particularly, where the anomalous conductivity is correlated with high heat flow and other geophysical and geological parameters.

  19. Geochemical and isotopic characterization of the ground water of Oued Laya

    International Nuclear Information System (INIS)

    Hkiri, Sabrine

    2010-01-01

    In the Sahel region of Sousse (Tunisia Center East), almost all of the deep groundwater has undergone over the last decade, a general decline of groundwater level. This decrease is caused by two factors, the intensive farming and drought. These aquifers, despite their often poor quality (high salinity), are increasingly used, so they are now home to intense exploitation, whose consequences have emerged as significant declines of groundwater level and degradation of the chemical quality of their water. This study concerns a groundwater aquifer that is under stress and anthropogenic climate severe enough: the coastal aquifer of Wad Laya present quality of groundwater qualified low salinity point of view compared to other neighboring aquifers. The salinity is apparently not related to over exploitation as the majority of coastal aquifers but seems it is due to the geological nature which forms the water table. The region's climate is semiarid with an average annual rainfall of 320 mm by 100 years; the FTE is 1750 mm / year resulting in a water deficit of more than 1.4 m / year. Renewable resources are estimated at 3.3 million m3, while for the levy is estimated to be 2.7 million m3 which the dry residue is currently spent 5g / l (CRDA Sousse, 2009). The objective of this study included hydrogeological characterization of the aquifer using geophysical tools and identification of mechanisms of salination using geochemical and isotopic tools to determine the possible origins of mineralization. For this campaign sampling and measurement was made in the region over a thirty water points in order to measure the electrical conductivity, groundwater level and analyze the chemical composition (major and trace elements). Initial findings from this study are summarized in: Completion of piezometric maps and potentiometric study of the evolution in some wells show a decline of water table caused by the increased exploitation and lower rainfall, which resulted in an increase in

  20. Calibration and Confirmation in Geophysical Models

    Science.gov (United States)

    Werndl, Charlotte

    2016-04-01

    For policy decisions the best geophysical models are needed. To evaluate geophysical models, it is essential that the best available methods for confirmation are used. A hotly debated issue on confirmation in climate science (as well as in philosophy) is the requirement of use-novelty (i.e. that data can only confirm models if they have not already been used before. This talk investigates the issue of use-novelty and double-counting for geophysical models. We will see that the conclusions depend on the framework of confirmation and that it is not clear that use-novelty is a valid requirement and that double-counting is illegitimate.

  1. Geophysical Methods for Investigating Ground-Water Recharge

    Science.gov (United States)

    Ferre, Ty P.A.; Binley, Andrew M.; Blasch, Kyle W.; Callegary, James B.; Crawford, Steven M.; Fink, James B.; Flint, Alan L.; Flint, Lorraine E.; Hoffmann, John P.; Izbicki, John A.; Levitt, Marc T.; Pool, Donald R.; Scanlon, Bridget R.

    2007-01-01

    that are currently available or under development for recharge monitoring. The material is written primarily for hydrogeologists. Uses of geophysical methods for improving recharge monitoring are explored through brief discussions and case studies. The intent is to indicate how geophysical methods can be used effectively in studying recharge processes and quantifying recharge. As such, the material constructs a framework for matching the strengths of individual geophysical methods with the manners in which they can be applied for hydrologic analyses. The appendix is organized in three sections. First, the key hydrologic parameters necessary to determine the rate, timing, and patterns of recharge are identified. Second, the basic operating principals of the relevant geophysical methods are discussed. Methods are grouped by the physical property that they measure directly. Each measured property is related to one or more of the key hydrologic properties for recharge monitoring. Third, the emerging conceptual framework for applying geophysics to recharge monitoring is presented. Examples of the application of selected geophysical methods to recharge monitoring are presented in nine case studies. These studies illustrate hydrogeophysical applications under a wide range of conditions and measurement scales, which vary from tenths of a meter to hundreds of meters. The case studies include practice-proven as well as emerging applications of geophysical methods to recharge monitoring.

  2. A new data logger for integrated geophysical monitoring

    Science.gov (United States)

    Orazi, Massimo; Peluso, Rosario; Caputo, Antonio; Giudicepietro, Flora; Martini, Marcello

    2015-04-01

    GILDA digital recorder is a data logger developed at Osservatorio Vesuviano (INGV). It provides excellent data quality with low power consumption and low production cost. It is widely used in the multi-parametric monitoring networks of Neapolitan volcanoes and Stromboli volcano. We have improved the characteristics of GILDA recorder to realize a robust user-oriented acquisition system for integrated geophysical monitoring. We have designed and implemented new capabilities concerning the use of the low rate channels to get data of environmental parameters of the station. We also improved the stand-alone version of the data logger. This version can be particularly useful for scientific experiments and to rapidly upgrade permanent monitoring networks. Furthermore, the local storage can be used as back-up for the monitoring systems in continuous transmission, in case of failure of the transmission system. Some firmware changes have been made in order to improve the performance of the instrument. In particular, the low rate acquisition channels were conditioned to acquire internal parameters of the recorder such as the temperature and voltage. A prototype of the new version of the logger is currently installed at Campi Flegrei for a experimental application. Our experiment is aimed at testing the new version of GILDA data logger in multi-board configuration for multiparametric acquisitions. A second objective of the experiment is the comparison of the recorded data with geochemical data acquired by a multiparametric geochemical station to investigate possible correlations between seismic and geochemical parameters. The target site of the experiment is "Bocca Grande" fumarole in Solfatara volcano. By exploiting the modularity of GILDA, for the experiment has been realized an acquisition system based on three dataloggers for a total of 12 available channels. One of GILDA recorders is the Master and the other two are Slaves. The Master is responsible for the initial

  3. Central Colorado Assessment Project (CCAP)-Geochemical data for rock, sediment, soil, and concentrate sample media

    Science.gov (United States)

    Granitto, Matthew; DeWitt, Ed H.; Klein, Terry L.

    2010-01-01

    This database was initiated, designed, and populated to collect and integrate geochemical data from central Colorado in order to facilitate geologic mapping, petrologic studies, mineral resource assessment, definition of geochemical baseline values and statistics, environmental impact assessment, and medical geology. The Microsoft Access database serves as a geochemical data warehouse in support of the Central Colorado Assessment Project (CCAP) and contains data tables describing historical and new quantitative and qualitative geochemical analyses determined by 70 analytical laboratory and field methods for 47,478 rock, sediment, soil, and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed either in the analytical laboratories of the USGS or by contract with commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects. In addition, geochemical data from 7,470 sediment and soil samples collected and analyzed under the Atomic Energy Commission National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program (henceforth called NURE) have been included in this database. In addition to data from 2,377 samples collected and analyzed under CCAP, this dataset includes archived geochemical data originally entered into the in-house Rock Analysis Storage System (RASS) database (used by the USGS from the mid-1960s through the late 1980s) and the in-house PLUTO database (used by the USGS from the mid-1970s through the mid-1990s). All of these data are maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB and from the NURE database were used to generate most of this dataset. In addition, USGS data that have been excluded previously from the NGDB because the data predate earliest USGS geochemical databases, or were once excluded for programmatic reasons

  4. Compiling Data from Geological, Mineralogical and Geophysical (IP/RS Studies on Mahour Deposit, Northwest of Deh-salm, Lut Block

    Directory of Open Access Journals (Sweden)

    Arash Gorabjeiri Puor

    2015-10-01

    Full Text Available Introduction The Mahour exploration area is a polymetallic system containing copper, zinc and silver. The mineralization can be seen in two forms of veins and disseminations. This area is structurally within the Lut block, west of Deh-salm Village. Recent exploration work and studies carried out by geologists on this volcanic-plutonic area of Lut demonstate its importance indicating new reserves of copper, gold, and lead and zinc. Several articles have been published on the Mahour deposit in recent years, including work on fluid inclusions (Mirzaei et al., 2012a; Mirzaei et al., 2012b. The present report aims at completion of previous studies on Mahour. During the course of this research, the IP/RS geophysical methods were used to locate the extent and depth of sulfide veins in order to locate drill sites. The IP/RS method has been used extensively worldwide in locating sulfide mineralization at deposits such as Olympic Dam in Australia (Esdale et al., 1987, Hishikari epithermal gold deposit in Kagoshima, Japan (Okada, 1995 and Cadia-Ridgeway copper and gold deposit in New South Wales, Australia (Rutley et al., 2001. Materials and Methods 1. Determination of mineralogy of ore and alteration by examination of 70 thin sections and 45 polished sections. 2. Compilation of geological and mineralization maps of the studied area at a scale of 1:1000. 3. Geological, alteration, mineralization and trace element geochemical studies of 6 drill holes. 4. IP/RS measurements for 2585 points on a rectangular grid with profile intervals of 50 meters and electrode intervals of 20 meters. 5. Interpretation of IP/RS results. Discussion The Mahour area is covered by a volcanic sequence of basalt, andesite, dacite, rhyolite and pyro-clastics. During the Late Eocene through Early Oligocene this volcanic complex was intruded by several diorite and quartz-diorite bodies, which were responsible for mineralization of the area. Mineralized veins hosted by dacite show NNE

  5. Site investigation - equipment for geological, geophysical, hydrogeological and hydrochemical characterization

    International Nuclear Information System (INIS)

    Almen, K.E.; Fridh, B.; Johansson, B.E.; Sehlstedt, M.

    1986-11-01

    The investigations are performed within a site investigation program. In total about 60,000 m of cored 56 mm boreholes have been drilled and investigated at eight study sites. A summarized description of the main investigation methods is included. Instruments for geophysical investigations contains equipment for ground measurements as well as for borehole logging. The Geophysical investigations including the borehole radar measurements, are indirect methods for the geological and hydrogeological characterization of the rock formation. Great effort has been laid on the development of hydrogeological instruments for hydraulic tests and groundwater head measurements. In order to obtain hydrochemical investigations with high quality, a complete system for sampling and analysis of ground water has been developed. (orig./PW)

  6. Geochemical Anomalies in the Sediments of Lake Druksiai

    International Nuclear Information System (INIS)

    Kleinas, A.

    1999-01-01

    In order to evaluate the impact of Ignalina Nuclear Power Plant (NPP) on natural processes in Lake Druksiai and accumulation of pollutants, in 19931997, carrying on the state scientific program, the Marine Geochemistry Division of the Institute of Geography performed lithological geochemical mapping of lake bottom sediments on a scale of 1 .50 000. The results obtained enabled to distinguish zones of higher anthropogenous geochemical load, where geochemical anomalies of pollutants, including oil hydrocarbons and heavy metals, had been taken into account. Applying concentration coefficients for oil hydrocarbons and heavy metals (Cr, Cu, Ni, Pb, and Zn) and their natural background, the attempt was made to differentiate natural and technogenous components in the geochemical anomalies As expected, the finer sediments -aleurite-pelite mud - showed amounts of oil hydrocarbons and heavy metals being 12.1 times higher than in fine sand - the most coarse of the sediments studied Sediments with organic mater exceeding 20% contained 11.7 times more pollutants than those with organic matter below 1 .5%. Calculations of concentration coefficients (CC) showed no elements in no stations exceeded 10 - the sediments did not reach the category of high pollution However, in many sites, the coefficients exceeded values of 1-2, thus, showing sediments attributable to the categories of weakly polluted or just polluted. Mapping model done by GIS methods (by superimposing schemes of pollutant CCs distribution in the lake and summing them) for geochemical anomalies two derivative map-schemes were obtained for oil hydrocarbons and heavy metals. They showed that clean sediments cover just 24.75% (according to the pollutant background for soil types) and 12.35% (according to the organic matter background for its amount intervals) lake bottom area. Zones slightly polluted by an element at least cover 69.7 and 80.29% of lake area, correspondingly; whereas zones slightly polluted by all

  7. Including geological information in the inverse problem of palaeothermal reconstruction

    Science.gov (United States)

    Trautner, S.; Nielsen, S. B.

    2003-04-01

    A reliable reconstruction of sediment thermal history is of central importance to the assessment of hydrocarbon potential and the understanding of basin evolution. However, only rarely do sedimentation history and borehole data in the form of present day temperatures and vitrinite reflectance constrain the past thermal evolution to a useful level of accuracy (Gallagher and Sambridge,1992; Nielsen,1998; Trautner and Nielsen,2003). This is reflected in the inverse solutions to the problem of determining heat flow history from borehole data: The recent heat flow is constrained by data while older values are governed by the chosen a prior heat flow. In this paper we reduce this problem by including geological information in the inverse problem. Through a careful analysis of geological and geophysical data the timing of the tectonic processes, which may influence heat flow, can be inferred. The heat flow history is then parameterised to allow for the temporal variations characteristic of the different tectonic events. The inversion scheme applies a Markov chain Monte Carlo (MCMC) approach (Nielsen and Gallagher, 1999; Ferrero and Gallagher,2002), which efficiently explores the model space and futhermore samples the posterior probability distribution of the model. The technique is demonstrated on wells in the northern North Sea with emphasis on the stretching event in Late Jurassic. The wells are characterised by maximum sediment temperature at the present day, which is the worst case for resolution of the past thermal history because vitrinite reflectance is determined mainly by the maximum temperature. Including geological information significantly improves the thermal resolution. Ferrero, C. and Gallagher,K.,2002. Stochastic thermal history modelling.1. Constraining heat flow histories and their uncertainty. Marine and Petroleum Geology, 19, 633-648. Gallagher,K. and Sambridge, M., 1992. The resolution of past heat flow in sedimentary basins from non-linear inversion

  8. Hydro geophysical Investigation for Groundwater Development at ...

    African Journals Online (AJOL)

    ADOWIE PERE

    lateritic sand, shale/clay, weathered layer, fractured basement and fresh basement respectively. Geo-electric sounding ... numerical modeling solutions. The electrical geophysical survey method is the detection of the surface effects produced by the.

  9. Exploring the oceans- The geophysical way

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.

    The evolution of the eastern continental margin of India (ECMI), the Bengal Fan and the Central Indian Basin (CIB) is a consequence of the breakup of India from the eastern Gondwanaland in Late Jurassic to Early Cretaceous. Recent marine geophysical...

  10. Geophysical field disturbances and quantum mechanics

    Directory of Open Access Journals (Sweden)

    Kuznetsov Vladimir

    2017-01-01

    Geophysical phenomena considered here have no clear and consistent interpretation in the context of classical physics. We attempt to involve the recent achievements of quantum physics namely the quantum entanglement between elementary particles implicated in considered phenomena.

  11. COLLADA Computing for Geophysical Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The COLLADATM open industry XML standard for 3D Graphics Exchange is applied for representation, combination and analysis of geophysical information from disparate...

  12. Marine geophysical data management and presentation system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.

    The Geophysical Data Management and Presentation System (GPDMPS) constitutes an integral part of the large Geological Oceanographic Database (GODBASE) which is under development at the Indian National Oceanographic Data Centre (INODC...

  13. A field guide to geophysics in archaeology

    CERN Document Server

    Oswin, John

    2009-01-01

    Geophysics operations in archaeology have become well known through exposure on television. However, the technique is presented as the action of specialists and something of a mystery, where people walk about with strange contraptions, and results appear from a computer. This is not the case, however. Some scientific knowledge is needed in order to understand how the machines work and what they detect but otherwise it is only necessary to know how to handle the instruments, how to survey a field and how to interpret the computer results. This book provides all the relevant information. It explains geophysics operations in archaeology, describes the science that gives the soil properties to measure and the means by which the instruments make their measurements. Dr John Oswin is in charge of the geophysics operation of the Bath and Camerton Archaeological Society and his work has recently been the subject of a television programme. He has taught many students how to use geophysical equipment.

  14. Tabletop Models for Electrical and Electromagnetic Geophysics.

    Science.gov (United States)

    Young, Charles T.

    2002-01-01

    Details the use of tabletop models that demonstrate concepts in direct current electrical resistivity, self-potential, and electromagnetic geophysical models. Explains how data profiles of the models are obtained. (DDR)

  15. A geological and geophysical data collection system

    Digital Repository Service at National Institute of Oceanography (India)

    Sudhakar, T.; Afzulpurkar, S.

    A geological and geophysical data collection system using a Personal Computer is described below. The system stores data obtained from various survey systems typically installed in a charter vessel and can be used for similar applications on any...

  16. LASL approach to uranium geochemical reconnaissance

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R.R. Jr.

    1977-01-01

    The US ERDA, as part of the NURE program, has initiated a nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR). The aims of the NURE program are to provide data on which to base more accurate estimates of US uranium reserves for long-range planning and to aid in meeting the nation's projected uranium demands into the next century. The HSSR objective is to complete, by 1980, a reconnaissance of the nation's surface waters, ground waters, and stream and lake sediments, to aid in assessment of uranium reserves and identification of areas of interest for exploration. Patterned after extensive uranium reconnaissance done in many other countries, the LASL project is comprised of the following five components: (1) organization and planning, which includes management, design, and execution; (2) field sampling, which includes orientation studies, generation of specifications, and contracting and inspection of field work; (3) sample receiving and analysis, which includes development of methods and hardware, quality assurance, and archival storage; (4) data handling and presentation, including verification, storage, output, and plotting; and (5) data evaluation and publication, which incorporates geochemical, geological, statistical, and empirical evaluation and report writing. The LASL approach to each component and the current status in each state are described.

  17. LASL approach to uranium geochemical reconnaissance

    International Nuclear Information System (INIS)

    Sharp, R.R. Jr.

    1977-01-01

    The US ERDA, as part of the NURE program, has initiated a nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR). The aims of the NURE program are to provide data on which to base more accurate estimates of US uranium reserves for long-range planning and to aid in meeting the nation's projected uranium demands into the next century. The HSSR objective is to complete, by 1980, a reconnaissance of the nation's surface waters, ground waters, and stream and lake sediments, to aid in assessment of uranium reserves and identification of areas of interest for exploration. Patterned after extensive uranium reconnaissance done in many other countries, the LASL project is comprised of the following five components: (1) organization and planning, which includes management, design, and execution; (2) field sampling, which includes orientation studies, generation of specifications, and contracting and inspection of field work; (3) sample receiving and analysis, which includes development of methods and hardware, quality assurance, and archival storage; (4) data handling and presentation, including verification, storage, output, and plotting; and (5) data evaluation and publication, which incorporates geochemical, geological, statistical, and empirical evaluation and report writing. The LASL approach to each component and the current status in each state are described

  18. Multiscale geophysical imaging of the critical zone

    Science.gov (United States)

    Parsekian, Andy; Singha, Kamini; Minsley, Burke J.; Holbrook, W. Steven; Slater, Lee

    2015-01-01

    Details of Earth's shallow subsurface—a key component of the critical zone (CZ)—are largely obscured because making direct observations with sufficient density to capture natural characteristic spatial variability in physical properties is difficult. Yet this inaccessible region of the CZ is fundamental to processes that support ecosystems, society, and the environment. Geophysical methods provide a means for remotely examining CZ form and function over length scales that span centimeters to kilometers. Here we present a review highlighting the application of geophysical methods to CZ science research questions. In particular, we consider the application of geophysical methods to map the geometry of structural features such as regolith thickness, lithological boundaries, permafrost extent, snow thickness, or shallow root zones. Combined with knowledge of structure, we discuss how geophysical observations are used to understand CZ processes. Fluxes between snow, surface water, and groundwater affect weathering, groundwater resources, and chemical and nutrient exports to rivers. The exchange of gas between soil and the atmosphere have been studied using geophysical methods in wetland areas. Indirect geophysical methods are a natural and necessary complement to direct observations obtained by drilling or field mapping. Direct measurements should be used to calibrate geophysical estimates, which can then be used to extrapolate interpretations over larger areas or to monitor changing processes over time. Advances in geophysical instrumentation and computational approaches for integrating different types of data have great potential to fill gaps in our understanding of the shallow subsurface portion of the CZ and should be integrated where possible in future CZ research.

  19. The remote sensing needs of Arctic geophysics

    Science.gov (United States)

    Campbell, W. J.

    1970-01-01

    The application of remote sensors for obtaining geophysical information of the Arctic regions is discussed. Two significant requirements are to acquire sequential, synoptic imagery of the Arctic Ocean during all weather and seasons and to measure the strains in the sea ice canopy and the heterogeneous character of the air and water stresses acting on the canopy. The acquisition of geophysical data by side looking radar and microwave sensors in military aircraft is described.

  20. National Geophysical Data Center Tsunami Data Archive

    Science.gov (United States)

    Stroker, K. J.; Dunbar, P. K.; Brocko, R.

    2008-12-01

    NOAA's National Geophysical Data Center (NGDC) and co-located World Data Center for Geophysics and Marine Geology long-term tsunami data archive provides data and derived products essential for tsunami hazard assessment, forecast and warning, inundation modeling, preparedness, mitigation, education, and research. As a result of NOAA's efforts to strengthen its tsunami activities, the long-term tsunami data archive has grown from less than 5 gigabyte in 2004 to more than 2 terabytes in 2008. The types of data archived for tsunami research and operation activities have also expanded in fulfillment of the P.L. 109-424. The archive now consists of: global historical tsunami, significant earthquake and significant volcanic eruptions database; global tsunami deposits and proxies database; reference database; damage photos; coastal water-level data (i.e. digital tide gauge data and marigrams on microfiche); bottom pressure recorder (BPR) data as collected by Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys. The tsunami data archive comes from a wide variety of data providers and sources. These include the NOAA Tsunami Warning Centers, NOAA National Data Buoy Center, NOAA National Ocean Service, IOC/NOAA International Tsunami Information Center, NOAA Pacific Marine Environmental Laboratory, U.S. Geological Survey, tsunami catalogs, reconnaissance reports, journal articles, newspaper articles, internet web pages, and email. NGDC has been active in the management of some of these data for more than 50 years while other data management efforts are more recent. These data are openly available, either directly on-line or by contacting NGDC. All of the NGDC tsunami and related databases are stored in a relational database management system. These data are accessible over the Web as tables, reports, and interactive maps. The maps provide integrated web-based GIS access to individual GIS layers including tsunami sources, tsunami effects, significant earthquakes

  1. A tool for Exploring Geophysical Data: The VGEE-IDV

    Science.gov (United States)

    Pandya, R. E.; Murray, D.

    2002-12-01

    The Visual Geophysical Exploration Environment (VGEE) is a suite of computer tools and accompanying online curricular units that enable students to develop physical insight from geophysical data sets. The VGEE curriculum is inquiry and visualization based. The curriculum begins by asking students to compare visualizations they construct from authentic geosciences data to their own conception of the geophysical phenomenon. This comparison encourages students to identify and challenge their own prior conceptions of the phenomenon, a necessary prerequisite to successful learning. Students then begin building correct understandings by identifying patterns and relationships within their visualizations. Students use idealized concept models that highlight physical principles to explain these patterns and relationships. Research, however, has shown that the physical insight gained from these idealized models isn't often applied to either the real world or to the data visualized. To address this, students can easily embed these idealized concept models into their visualizations; there the idealized models respond to the real physical conditions of the geophysical data. The entire inquiry process is built around multi-dimensional and multi-variable visualizations of real geophysical data. Advantages of visualization include its using a natural human talent and its removing mathematics as a barrier to insight. Multi-dimensional and multi-variable visualizations offer the additional advantage of integrated perspectives; rather than asking learners to mentally combine two-dimensional representations of different variables, the learners can navigate through a three-dimensional time-varying representation and get a holistic view. Finally, learner constructed visualizations offer the students a experience with scientific tools, a chance to tailor their investigation to their own misconceptions, and the potential for more robust understanding than prepared visualizations. The

  2. Non-Seismic Geophysical Approaches to Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hoversten, G.M.; Gasperikova, Erika

    2004-09-01

    This chapter considers the application of a number of different geophysical techniques for monitoring geologic sequestration of CO2. The relative merits of the seismic, gravity, electromagnetic (EM) and streaming potential (SP) geophysical techniques as monitoring tools are examined. An example of tilt measurements illustrates another potential monitoring technique, although it has not been studied to the extent of other techniques in this chapter. This work does not represent an exhaustive study, but rather demonstrates the capabilities of a number of geophysical techniques on two synthetic modeling scenarios. The first scenario represents combined CO2 enhance oil recovery (EOR) and sequestration in a producing oil field, the Schrader Bluff field on the north slope of Alaska, USA. The second scenario is of a pilot DOE CO2 sequestration experiment scheduled for summer 2004 in the Frio Brine Formation in South Texas, USA. Numerical flow simulations of the CO2 injection process for each case were converted to geophysical models using petrophysical models developed from well log data. These coupled flow simulation geophysical models allow comparrison of the performance of monitoring techniques over time on realistic 3D models by generating simulated responses at different times during the CO2 injection process. These time-lapse measurements are used to produce time-lapse changes in geophysical measurements that can be related to the movement of CO2 within the injection interval.

  3. Time-lapse electrical geophysical monitoring of amendment-based biostimulation

    Science.gov (United States)

    Johnson, Timothy C.; Versteeg, Roelof J.; Day-Lewis, Frederick D.; Major, William; Lane, John W.

    2015-01-01

    Biostimulation is increasingly used to accelerate microbial remediation of recalcitrant groundwater contaminants. Effective application of biostimulation requires successful emplacement of amendment in the contaminant target zone. Verification of remediation performance requires postemplacement assessment and contaminant monitoring. Sampling-based approaches are expensive and provide low-density spatial and temporal information. Time-lapse electrical resistivity tomography (ERT) is an effective geophysical method for determining temporal changes in subsurface electrical conductivity. Because remedial amendments and biostimulation-related biogeochemical processes often change subsurface electrical conductivity, ERT can complement and enhance sampling-based approaches for assessing emplacement and monitoring biostimulation-based remediation.Field studies demonstrating the ability of time-lapse ERT to monitor amendment emplacement and behavior were performed during a biostimulation remediation effort conducted at the Department of Defense Reutilization and Marketing Office (DRMO) Yard, in Brandywine, Maryland, United States. Geochemical fluid sampling was used to calibrate a petrophysical relation in order to predict groundwater indicators of amendment distribution. The petrophysical relations were field validated by comparing predictions to sequestered fluid sample results, thus demonstrating the potential of electrical geophysics for quantitative assessment of amendment-related geochemical properties. Crosshole radar zero-offset profile and borehole geophysical logging were also performed to augment the data set and validate interpretation.In addition to delineating amendment transport in the first 10 months after emplacement, the time-lapse ERT results show later changes in bulk electrical properties interpreted as mineral precipitation. Results support the use of more cost-effective surface-based ERT in conjunction with limited field sampling to improve spatial

  4. Time-Lapse Electrical Geophysical Monitoring of Amendment-Based Biostimulation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Timothy C.; Versteeg, Roelof; Day-Lewis, Frederick D.; Major, William; Lane, John W.

    2015-12-02

    Biostimulation is increasingly used to accelerate microbial remediation of recalcitrant groundwater contaminants. Effective application of biostimulation requires successful emplacement of amendment in the contaminant target zone. Verification of remediation performance requires postemplacement assessment and contaminant monitoring. Sampling based approaches are expensive and provide low-density spatial and temporal information. Time-lapse electrical resistivity tomography (ERT) is an effective geophysical method for determining temporal changes in subsurface electrical conductivity. Because remedial amendments and biostimulation-related biogeochemical processes often change subsurface electrical conductivity, ERT can complement and enhance sampling-based approaches for assessing emplacement and monitoring biostimulation-based remediation. Field studies demonstrating the ability of time-lapse ERT to monitor amendment emplacement and behavior were performed during a biostimulation remediation effort conducted at the Department of Defense Reutilization and Marketing Office (DRMO) Yard, in Brandywine, Maryland, United States. Geochemical fluid sampling was used to calibrate a petrophysical relation in order to predict groundwater indicators of amendment distribution. The petrophysical relations were field validated by comparing predictions to sequestered fluid sample results, thus demonstrating the potential of electrical geophysics for quantitative assessment of amendment-related geochemical properties. Crosshole radar zero-offset profile and borehole geophysical logging were also performed to augment the data set and validate interpretation. In addition to delineating amendment transport in the first 10 months after emplacement, the time-lapse ERT results show later changes in bulk electrical properties interpreted as mineral precipitation. Results support the use of more cost-effective surfacebased ERT in conjunction with limited field sampling to improve spatial

  5. SIAM conference on inverse problems: Geophysical applications. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This conference was the second in a series devoted to a particular area of inverse problems. The theme of this series is to discuss problems of major scientific importance in a specific area from a mathematical perspective. The theme of this symposium was geophysical applications. In putting together the program we tried to include a wide range of mathematical scientists and to interpret geophysics in as broad a sense as possible. Our speaker came from industry, government laboratories, and diverse departments in academia. We managed to attract a geographically diverse audience with participation from five continents. There were talks devoted to seismology, hydrology, determination of the earth`s interior on a global scale as well as oceanographic and atmospheric inverse problems.

  6. Geophysical borehole logging. Final disposal of spent fuel

    International Nuclear Information System (INIS)

    Rouhiainen, P.

    1984-01-01

    Teollisuuden Voima Oy (Industrial Power Company Ltd.) will take precautions for final disposal of spent fuel in the Finnish bedrock. The first stage of the site selection studies includes drilling of a deep borehole down to approximately 1000 meters in the year 1984. The report deals with geophysical borehole logging methods, which could be used for the studies. The aim of geophysical borehole logging methods is to descripe specially hydrogeological and structural features. Only the most essential methods are dealt with in this report. Attention is paid to the information produced with the methods, derscription of the methods, interpretation and limitations. The feasibility and possibilities for the aims are evaluated. The evaluations are based mainly on the results from Sweden, England, Canada and USA as well as experiencies gained in Finland

  7. Space Geodesy Monitoring Mass Transport in Global Geophysical Fluids

    Science.gov (United States)

    Chao, Benjamin F.

    2004-01-01

    Mass transports occurring in the atmosphere-hydrosphere-cryosphere-solid Earth-core system (the 'global geophysical fluids') are important geophysical phenomena. They occur on all temporal and spatial scales. Examples include air mass and ocean circulations, oceanic and solid tides, hydrological water and idsnow redistribution, mantle processes such as post-glacial rebound, earthquakes and tectonic motions, and core geodynamo activities. The temporal history and spatial pattern of such mass transport are often not amenable to direct observations. Space geodesy techniques, however, have proven to be an effective tool in monitorihg certain direct consequences of the mass transport, including Earth's rotation variations, gravitational field variations, and the geocenter motion. Considerable advances have been made in recent years in observing and understanding of these geodynamic effects. This paper will use several prominent examples to illustrate the triumphs in research over the past years under a 'Moore's law' in space geodesy. New space missions and projects promise to further advance our knowledge about the global mass transports. The latter contributes to our understanding of the geophysical processes that produce and regulate the mass transports, as well as of the solid Earth's response to such changes in terms of Earth's mechanical properties.

  8. Bringing 3D Printing to Geophysical Science Education

    Science.gov (United States)

    Boghosian, A.; Turrin, M.; Porter, D. F.

    2014-12-01

    3D printing technology has been embraced by many technical fields, and is rapidly making its way into peoples' homes and schools. While there is a growing educational and hobbyist community engaged in the STEM focused technical and intellectual challenges associated with 3D printing, there is unrealized potential for the earth science community to use 3D printing to communicate scientific research to the public. Moreover, 3D printing offers scientists the opportunity to connect students and the public with novel visualizations of real data. As opposed to introducing terrestrial measurements through the use of colormaps and gradients, scientists can represent 3D concepts with 3D models, offering a more intuitive education tool. Furthermore, the tactile aspect of models make geophysical concepts accessible to a wide range of learning styles like kinesthetic or tactile, and learners including both visually impaired and color-blind students.We present a workflow whereby scientists, students, and the general public will be able to 3D print their own versions of geophysical datasets, even adding time through layering to include a 4th dimension, for a "4D" print. This will enable scientists with unique and expert insights into the data to easily create the tools they need to communicate their research. It will allow educators to quickly produce teaching aids for their students. Most importantly, it will enable the students themselves to translate the 2D representation of geophysical data into a 3D representation of that same data, reinforcing spatial reasoning.

  9. Ore and rock mass characterization using borehole geophysics

    OpenAIRE

    Wänstedt, Stefan

    1997-01-01

    A geophysical log represents the measurement of a geophysical parameter along a borehole, plotted against time or depth. A variety of geophysical logging tools exist that measure different geophysical parameters. Some geophysical instruments react to the lithological changes along the borehole, others to the fluid within or around the borehole, but very few react solely to a single feature. In every case the user must determine what effect the borehole and its surroundings have on the measure...

  10. Petrographic features, geochemical trends and mass balance ...

    African Journals Online (AJOL)

    Petrographic features, geochemical trends and mass balance computation, in relation to the evolution of anatectic migmatites in the granulite facies terrain of the Manalur area, Tamil Nadu, south India.

  11. Coupling of transport and geochemical models

    International Nuclear Information System (INIS)

    Noy, D.J.

    1986-01-01

    This report considers mass transport in the far-field of a radioactive waste repository, and detailed geochemical modelling of the ground-water in the near-field. A parallel approach to this problem of coupling transport and geochemical codes is the subject of another CEC report (ref. EUR 10226). Both studies were carried out in the framework of the CEC project MIRAGE. (Migration of radionuclides in the geosphere)

  12. Understanding biogeobatteries: Where geophysics meets microbiology

    Energy Technology Data Exchange (ETDEWEB)

    Revil, A.; Mendonca, C.A.; Atekwana, E.A.; Kulessa, B.; Hubbard, S.S.; Bohlen, K.

    2009-08-15

    Although recent research suggests that contaminant plumes behave as geobatteries that produce an electrical current in the ground, no associated model exists that honors both geophysical and biogeochemical constraints. Here, we develop such a model to explain the two main electrochemical contributions to self-potential signals in contaminated areas. Both contributions are associated with the gradient of the activity of two types of charge carriers, ions and electrons. In the case of electrons, bacteria act as catalysts for reducing the activation energy needed to exchange the electrons between electron donor and electron acceptor. Possible mechanisms that facilitate electron migration include iron oxides, clays, and conductive biological materials, such as bacterial conductive pili or other conductive extracellular polymeric substances. Because we explicitly consider the role of biotic processes in the geobattery model, we coined the term 'biogeobattery'. After theoretical development of the biogeobattery model, we compare model predictions with self-potential responses associated with laboratory and field-scale conducted in contaminated environments. We demonstrate that the amplitude and polarity of large (>100 mV) self-potential signatures requires the presence of an electronic conductor to serve as a bridge between electron donors and acceptors. Small self-potential anomalies imply that electron donors and electron acceptors are not directly interconnected, but instead result simply from the gradient of the activity of the ionic species that are present in the system.

  13. Generalized rheology and geophysical consequences

    Science.gov (United States)

    Caputo, Michele

    1985-06-01

    In some portions of the Earthś crust one finds stresses and creeps which are incompatible with the local geologic history and/or the generally accepted rheological models of Voigt, or Maxwell or Standard linear solid. Also there is no reason to accept that the rheology of the Earth is represented by mathematical formulae modeling combinations of simplicistic springs and dash pots which lead to represent the phenomenon by means of first order time derivatives of stress and/or strains. We describe here an attempt to obtain a rheological model for the lithosphere which is more realistic and flexible than the Voigt, the Maxwell and the Standard linear solid models which are generally used in geophysics and geology. In this model the first-order derivatives of Maxwell stress-strain relations are replaced by z-order derivatives; the resulting creep rates are variable functions of time as indicated by laboratory observations. In the one-dimensional case as well as in the case of the sphere the relaxation rate after a given time is a decreasing function of time. A small value of z could explain the residual deviatoric stress present in the Fennoscandia and Canadian Shields (Herget, 1980; Leijon et al., 1981) and the deviatoric stress present in the Rocky Mountains and in the Appalachian Range (Caputo et al., 1985) which seem stable and were formed many tens of millions of years ago. A small value of z would also explain why the seismicity is decreasing with lithospheric age (Stein, 1979; Bergman and Solomon, 1980) but is still present 100 millions of years after the origin of the lithosphere which implies a relevant residual shear stress after long time. If one wants to take into account the effect of temperature then one should consider that there is evidence that in some materials the creep rate is linearly increasing with temperature in the range between 100°C to 400°C (Caputo, 1983) and that it is independent of the confining pressure; then one would infer that the

  14. The University of Texas Institute for Geophysics Marine Geology and Geophysics Field Course

    Science.gov (United States)

    Davis, M. B.; Gulick, S. P.; Allison, M. A.; Goff, J. A.; Duncan, D. D.; Saustrup, S.

    2011-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers an intensive three-week marine geology and geophysics field course during the spring-summer intersession. Now in year five, the course provides hands-on instruction and training for graduate and upper-level undergraduate students in data acquisition, processing, interpretation, and visualization. Techniques covered include high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples (e.g., core description, grain size analysis, x-radiography, etc.). Students seek to understand coastal and sedimentary processes of the Gulf Coast and continental shelf through application of these techniques in an exploratory mode. Students participate in an initial three days of classroom instruction designed to communicate geological context of the field area (which changes each year) along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. In the field, students rotate between two small research vessels: one vessel, the 22' aluminum-hulled R/V Lake Itasca, owned and operated by UTIG, is used principally for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA's R/V Manta or the R/V Acadiana, operated by the Louisiana Universities Marine Consortium, is used primarily for high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, gravity coring, and vibracoring. While at sea, students assist with survey design, learn instrumentation set up, acquisition parameters, data quality control, and safe instrument deployment and retrieval. In teams of three, students work in onshore field labs preparing sediment samples for particle size analysis and initial data processing. During the course's final week, teams

  15. Version 4. 00 of the MINTEQ geochemical code

    Energy Technology Data Exchange (ETDEWEB)

    Eary, L.E.; Jenne, E.A.

    1992-09-01

    The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

  16. Version 4.00 of the MINTEQ geochemical code

    Energy Technology Data Exchange (ETDEWEB)

    Eary, L.E.; Jenne, E.A.

    1992-09-01

    The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

  17. Living microorganisms change the information (Shannon) content of a geophysical system.

    Science.gov (United States)

    Tang, Fiona H M; Maggi, Federico

    2017-06-12

    The detection of microbial colonization in geophysical systems is becoming of interest in various disciplines of Earth and planetary sciences, including microbial ecology, biogeochemistry, geomicrobiology, and astrobiology. Microorganisms are often observed to colonize mineral surfaces, modify the reactivity of minerals either through the attachment of their own biomass or the glueing of mineral particles with their mucilaginous metabolites, and alter both the physical and chemical components of a geophysical system. Here, we hypothesise that microorganisms engineer their habitat, causing a substantial change to the information content embedded in geophysical measures (e.g., particle size and space-filling capacity). After proving this hypothesis, we introduce and test a systematic method that exploits this change in information content to detect microbial colonization in geophysical systems. Effectiveness and robustness of this method are tested using a mineral sediment suspension as a model geophysical system; tests are carried out against 105 experiments conducted with different suspension types (i.e., pure mineral and microbially-colonized) subject to different abiotic conditions, including various nutrient and mineral concentrations, and different background entropy production rates. Results reveal that this method can systematically detect microbial colonization with less than 10% error in geophysical systems with low-entropy background production rate.

  18. Geophysical monitoring as an information source of rock massif behaviour

    Directory of Open Access Journals (Sweden)

    Pavel Bláha

    2008-06-01

    Full Text Available Geophysical measurements are an integral part of engineering-geological investigation where theypresent a wide range of useful information about the tested geological medium and about its geotechnicalqualities. Lately, repeated geophysical measurements in different time intervals have been used to judgethe changes occurring in the rock massif. These measurements bear the characteristics of total monitoring.This total monitoring contains series of repeated measurements and further an integrated spectrum of linkedactivities including evaluation, comparison with the warning state and making a decision about takingprecautions. From the range of geophysical methods and methodologies used for monitoring in full sensewe may mention, for example, continuous seismoacoustic measurements in mining constructions; (whichmay result even in recalling of the personnel, and further, also seismic measurements in the surroundingsof atomic power stations and measurements considering the protection against radioactive elements and their decay components.As a full monitoring we may also classify measurements in dumping sites with the aid of repeated geoelectrical measurements in the system of fixed electrodes under impermeable foils.These measurements are mostly carried out from time to time followed by taking immediate action when the foil is found damaged. In practice the term monitoring is used, although not very correctly, for all periodically repeated measurements, which do not result in taking action or interference, but supply a wide range of information about the rock massif behavior in time.

  19. WLS software for the Los Alamos geophysical instrumentation truck

    International Nuclear Information System (INIS)

    Ideker, C.D.; LaDelfe, C.M.

    1985-01-01

    Los Alamos National Laboratory's capabilities for special downhole geophysical well logging has increased steadily over the past few years. Software was developed originally for each individual tool as it became operational. With little or no standardization for tool software modules, software development became redundant, time consuming, and cost ineffective. With long-term use and the rapid evolution of well logging capacity in mind. Los Alamos and EG and G personnel decided to purchase a software system. The system was designed to offer: wide-range use and programming flexibility; standardization subroutines for tool module development; user friendly operation which would reduce training time; operator error checking and alarm activation; maximum growth capacity for new tools as they are added to the inventory; and the ability to incorporate changes made to the computer operating system and hardware. The end result is a sophisticated and flexible software tool and for transferring downhole geophysical measurement data to computer disk files. This paper outlines the need, design, development, and implementation of the WLS software for geophysical data acquisition. A demonstration and working examples are included in the presentation

  20. Geological and geophysical methods for monitoring of heritage structures

    Science.gov (United States)

    Kulynych, Anna

    2017-04-01

    Using the analysis of geological and geophysical survey of the soil conditions of the site where the architectural landmarks of Kyiv are concentrated the research proposes to develop an optimal set of geological and geophysical studies aimed at monitoring and evaluating the impact of underflooding, risk of landslide and increase of seismic magnitude on the upper portion of geological cross-section. The research offers suggestions concerning the establishment of a monitoring system for the principal sites where the architectural heritage is located. As the earthquake origins are not scattered randomly but located within the relatively narrow zones of active faults, that is, the places most exposed to rapid geodynamic shifts, active faults and blocks they form are one of the main signs for identifying potential seismogenic areas. From the point of view of the present geodynamic instability the morphostructural neotectonic points characterized by the high degree of tectonic fragmentation, including within the upper portion of the sedimentary cover, the high values of relief energy and activation of exogenous processes deserve special attention. The research develops the comparison of areas with increased seismic impacts allocated according to geophysical data with neotectonic structural plan, allows to conclude about their suitability for morphostructural neotectonic points and some sections of active faults exactly that is important to consider when constructing new buildings and protecting the existing ones.

  1. SQUID use for Geophysics: finding billions of dollars

    Science.gov (United States)

    Foley, Catherine

    2014-03-01

    Soon after their discovery, Jim Zimmerman saw the potential of using Superconducting Quantum Interference Devices, SQUIDs, for the study of Geophysics and undertook experiments to understand the magnetic phenomena of the Earth. However his early experiments were not successful. Nevertheless up to the early 1980's, some research effort in the use of SQUIDs for geophysics continued and many ideas of how you could use SQUIDs evolved. Their use was not adopted by the mining industry at that time for a range of reasons. The discovery of high temperature superconductors started a reinvigoration in the interest to use SQUIDs for mineral exploration. Several groups around the world worked with mining companies to develop both liquid helium and nitrogen cooled systems. The realisation of the achievable sensitivity that contributed to successful mineral discoveries and delineation led to real financial returns for miners. By the mid 2000's, SQUID systems for geophysics were finally being offered for sale by several start-up companies. This talk will tell the story of SQUID use in geophysics. It will start with the early work of the SQUID pioneers including that of Jim Zimmerman and John Clarke and will also cover the development since the early 1990's up to today of a number of magnetometers and gradiometers that have been successfully commercialised and used to create significant impact in the global resources industry. The talk will also cover some of the critical technical challenges that had to be overcome to succeed. It will focus mostly on magnetically unshielded systems used in the field although some laboratory-based systems will be discussed.

  2. Geophysical images of basement rocks. Geophysical images in the Guianese basement. Airborne geophysical campaign in French Guiana - 1996

    International Nuclear Information System (INIS)

    Delor, C.; Perrin, J.; Truffert, C.; Asfirane, F.; Rossi, Ph.; Bonjoly, D.; Dubreuihl, J.; Chardon, D.

    1998-01-01

    The French Office for Geological and Mining Research (BRGM) has carried out a high sensitivity airborne geophysical survey of northern French Guiana during the second half of 1996. The aim was to realize a high resolution magnetic and gamma spectrometric mapping for future prospecting, land use and environment management. This paper describes in details the geophysical campaign, the material used, the navigation techniques, the processing of magnetic data, the gamma radiation sources used, the spectrometric calibrations and the geologic interpretation of the results. (J.S.)

  3. Geophysical investigations applied to site selection for the radioactive waste disposal; Investigacoes geofisicas aplicadas na selecao de um repositorio de rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Samir; Dornelles, Gerson; Pedrozo, Geraldo Arholdi [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    1993-07-01

    In this work the geophysical exploratory techniques and the results obtained for the selection of a candidate site for the final repository of the radioactive waste containing cesium-137 generated by the Goiania accident occurred in September 1987, are described. The studies were performed in an area of about 100 hectares where is located the present radioactive waste provisional repository. the geophysical investigations using electromagnetic methods (VLF-EM), electric drillings and surface and sub-surface radiometry allowed for the area monitoring and provided the geophysical parameters necessary for understanding the structural and stratigraphic context. Furthermore, they will provide data for the geotechnical, geochemical and hydrogeological investigations as well as for the engineering conceptual project for the repository construction. (author)

  4. Role of geochemical background at evaluation of investment attractiveness of recreational territories

    Directory of Open Access Journals (Sweden)

    Vdovina Ol'ga Konstantinovna

    2014-09-01

    Full Text Available The article shows the role of natural geochemical background when estimating investment attractiveness of recreational areas. It is noted, that geochemical background influence on people's sickness rate isn't considered now. Though it's understood, that even insignificant increase of geochemical background in relation to percentage abundance of Earth crest may lead to endemic diseases of people, animals and plants. An indicator of geochemical endemicity areas was proposed for assessing the impact of storage elements and of a lack of geological environment on human health. Thanks to this measure, and taking into account landscape features of the area, the authors allocated lands, dangerous and potentially dangerous in terms of endemicity. The importance of ratings was achieved by the use of those factors that could have a great influence on the cost of land development. This includes, first of all, the factors that affect population health, and economic and geographic factors that minimize the cost of the territory development and the factors that give rise to financial risks and risks of human losses. The main risk factors include: potential ecological and geochemical risk; high absolute heights, development and activity of dangerous geological processes and phenomena. Systemacity of researches was reached by using factors, that characterize the object from different aspects; readiness of area infrastructure to its exploration and possible risks. Objectivity was achieved by the use of figures obtained from the results of geochemical and engineering surveys with their metrological support.

  5. Geophysical Measurements at Merseburg Cathedral

    Science.gov (United States)

    Meier, Thomas; Erkul, Ercan; Schulte-Kortnack, Detlef; Sobott, Robert; Hilbert, Helene; Esel, Yunus; Tesch, Marcel; Wiemann, Timo

    2017-04-01

    Merseburg Cathedral has been founded in 1015 by Bishop Thietmar von Merseburg and has been converted into a gothic cathedral from 1510 to 1517 by Bishop Thilo von Trotha. The cathedral together with the cloister, the castle and several appurtenant buildings are well preserved. The entire complex represents one of the most complete examples of medieval royal palaces and bishop's sees in Germany northeast of the Roman Limes. Here we present examples of geophysical measurements at the cathedral namely ultrasonic surface measurements, ground penetrating radar (GPR) as well as thermographic measurements. Ultrasonic surface measurements have been carried out at epitaphs made of sandstone to quantify changes in stone properties due to weathering. The 95 measurements reveal a strong variability in Rayleigh wave velocities ranging from about 800 m/s to 2000 m/s. Unweathered parts of the sandstone epitaphs show Rayleigh wave velocities of about 1500 m/s. A reduction in Rayleigh wave velocities hints at loosening of the rock surface whereas an increase is due to surficial black crusts with pores filled mainly by gypsum. Waveform inversion of the dispersed Rayleigh waveform yields depth profiles of the shear-wave velocity indicating the thickness of altered surficial layers. Also a loosening below the black crust may be detected non-destructively. A number of measurements have been repeated after one year and after a rainy day. Statistical analysis shows that random errors in Rayleigh wave velocities are less than about 3 %. Increase of moisture in porous sandstones leads to stronger damping of the Rayleigh wave and consequently to a reduction in Rayleigh wave velocities by up to about 10 %. At strongly altered epitaphs a reduction in Rayleigh wave velocity by up to 20 % has been observed within one year. Within one day an increase of up to about 7 % may indicate stiffening of black crusts due to moisture absorption. GPR measurements have been performed at several locations

  6. Creating a Research Experience in an Undergraduate Geophysics Course: Integrated Geophysical Study of the Silver Creek Fault, Santa Clara Valley, California

    Science.gov (United States)

    Reed, D. L.; Williams, R.

    2006-12-01

    An undergraduate geophysics course at the San Jose State University was redesigned to focus on providing students with an integrated research experience that included both formative and summative assessments of learning. To this end, the students carried out four geophysical studies (gravity, magnetic, refraction, and reflection) across the inferred location of the Silver Creek fault, which is buried by the Quaternary alluvium of the Santa Clara Valley within walking distance of the university. The seismic experiments were made possible with equipment loaned by Geometrics Inc. and seismic and borehole data first acquired during a joint study by the U.S. Geological Survey and the Santa Clara Valley Water District. Three field reports, one produced after each of the first three field experiments, provided formative assessment of each student's understanding of the geophysical method, its application to the primary research objective of defining the location and structure of the Silver Creek fault, and their ability to produce a manuscript of professional quality. After each of the field reports, students were required to rewrite the report, based on feedback provided by the instructor, as well as incorporate the analysis and interpretation of the subsequent geophysical study. Students also modified conclusions of the preceding surveys in order to produce an internally consistent interpretation with each new analysis. Regional geologic relations and borehole data provided additional constraints to interpretations based on the geophysical analyses. For summative assessment, students submitted a final manuscript that had undergone three revisions as well as presented an integrated geophysical study of the Silver Creek fault based on the four geophysical experiments. The quality of the field reports showed marked improvement with each successive submission during the semester and were significantly better than in previous versions of the course, which featured various

  7. Geophysics: creativity and the archaeological imagination

    Directory of Open Access Journals (Sweden)

    Rose Ferraby

    2017-06-01

    Full Text Available This paper article explores archaeology as a creative practice by engaging specifically with the processes and visuals of geophysics. An area of archaeology considered highly scientific, a different way of looking reveals geophysics to be a poetic form of landscape study. The processes used to collect, alter, interpret and visualize visualise the data are creative acts that have parallels with more easily recognizable recognisable arts practices such as painting, drawing or photography. The paper article explores the ideas behind ways of seeing, the archaeological imagination, technologies and process. The section that follows explores the different elements of work and the ways of seeing and thinking they inspire. The paper article ends by showcasing how other arts practices can give alternative perspectives on geophysics and how these can in turn influence fine art.

  8. Geochemical behavior of disposed radioactive waste

    International Nuclear Information System (INIS)

    Barney, G.S.; Navratil, J.D.; Schulz, W.W.

    1984-01-01

    The papers in this book are organized to cover the chemical aspects that are important to understanding the behavior of disposed radioactive wastes. These aspects include radionuclide sorption and desorption, solubility of radionuclide compounds, chemical species of radionuclides in natural waters, hydrothermal geochemical reactions, measurements of radionuclide migration, solid state chemistry of wastes, and waste-form leaching behavior. The information in each of the papers is necessary to predict the transport of radionuclides from wastes via natural waters and thus to predict the safety of the disposed waste. Radionuclide transport in natural waters is strongly dependent on sorption, desorption, dissolution, and precipitation processes. The first two papers discuss laboratory investigations of these processes. Descriptions of sorption and desorption behavior of important radionuclides under a wide range of environmental conditions are presented in the first section. Among the sorbents studied are basalt interbed solids, granites, clays, sediments, hydrous oxides, and pure minerals. Effects of redox conditions, groundwater composition and pH on sorption reactions are described

  9. Virtual Geophysics Laboratory: Exploiting the Cloud and Empowering Geophysicsts

    Science.gov (United States)

    Fraser, Ryan; Vote, Josh; Goh, Richard; Cox, Simon

    2013-04-01

    source tools. While developed to provide the geophysics research community with a sustainable platform and scalable infrastructure; VGL has also developed a number of concepts, patterns and generic components of which have been reused for cases beyond geophysics, including natural hazards, satellite processing and other areas requiring spatial data discovery and processing. Future plans for VGL include a number of improvements in both functional and non-functional areas in response to its user community needs and advancement in information technologies. In particular, research is underway in the following areas (a) distributed and parallel workflow processing in the cloud, (b) seamless integration with various cloud providers, and (c) integration with virtual laboratories representing other science domains. Acknowledgements: VGL was developed by CSIRO in collaboration with Geoscience Australia, National Computational Infrastructure, Australia National University, Monash University and University of Queensland, and has been supported by the Australian Government's Education Investment Funds through NeCTAR.

  10. Geophysical methods for evaluation of plutonic rocks

    International Nuclear Information System (INIS)

    Gibb, R.A.; Scott, J.S.

    1986-04-01

    Geophysical methods are systematically described according to the physical principle and operational mode of each method, the type of information produced, limitations of a technical and/or economic nature, and the applicability of the method to rock-mass evaluation at Research Areas of the Nuclear Fuel Waste Management Program. The geophysical methods fall into three categories: (1) airborne and other reconnaissance surveys, (2) detailed or surface (ground) surveys, and (3) borehole or subsurface surveys. The possible roles of each method in the site-screening and site-evaluation processes of disposal vault site selection are summarized

  11. Nonlinear regularization with applications in geophysics

    DEFF Research Database (Denmark)

    Berglund, Eva Ann-Charlotte

    2002-01-01

    geophysical inverse problems: a seismic tomography problem, and a geoelectrical sounding problem. We found that all four methods gave reasonable solutions for the two geophysical problem. However, the inexact Gauss-Newton method converged faster than the others for the seismic tomography problem......, and the inexact Gauss-Newton method and the IRGN method work better than the other two for the geoelectrical sounding problem. However, for the nonlinear Hammerstein integral equation the inexact Gauss-Newton method diverges, and the IRGN method converges fastest. The work presented here also considers linear ill...

  12. Geochemical prospecting for rare earth elements using termite mound materials

    Science.gov (United States)

    Horiuchi, Yu; Ohno, Tetsuji; Hoshino, Mihoko; Shin, Ki-Cheol; Murakami, Hiroyasu; Tsunematsu, Maiko; Watanabe, Yasushi

    2014-12-01

    The Blockspruit fluorite prospect, located in North West State of the Republic of South Africa, occurs within an actinolite rock zone that was emplaced into the Kenkelbos-type granite of Proterozoic age. There are a large number of termite mounds in the prospect. For geochemical prospecting for rare earth elements (REEs), in total, 200 samples of termite mound material were collected from actinolite rock and granite zones in the prospect. Geochemical analyses of these termite mound materials were conducted by two methods: portable X-ray fluorescence (XRF) spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS). Comparison of the two methods broadly indicates positive correlations of REEs (La, Ce, Pr, Nd, and Y), in particular Y and La having a strong correlation. As the result of modal abundance analyses, the actinolite rock at surface mainly consists of ferro-actinolite (89.89 wt%) and includes xenotime (0.26 wt%) and monazite (0.21 wt%) grains as REE minerals. Termite mound materials from actinolite rock also contain xenotime (0.27 wt%) and monazite (0.41 wt%) grains. In addition, termite mound materials from the actinolite rock zone have high hematite and Fe silicate contents compared to those from granite zone. These relationships suggest that REE minerals in termite mound materials originate form actinolite rock. Geochemical anomaly maps of Y, La, and Fe concentrations drawn based on the result of the portable XRF analyses show that high concentrations of these elements trend from SW to NE which broadly correspond to occurrences of actinolite body. These results indicate that termite mounds are an effective tool for REE geochemical prospection in the study area for both light REEs and Y, but a more detailed survey is required to establish the distribution of the actinolite rock body.

  13. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates

    Science.gov (United States)

    Atchley, Adam L.; Navarre-Sitchler, Alexis K.; Maxwell, Reed M.

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb2 +) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb2 + concentrations within the plume. Dissimilarities between ensemble Pb2 + concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb2 + concentrations are the same for all three

  14. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates.

    Science.gov (United States)

    Atchley, Adam L; Navarre-Sitchler, Alexis K; Maxwell, Reed M

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb(2+)) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb(2+) concentrations within the plume. Dissimilarities between ensemble Pb(2+) concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb(2+) concentrations are the same for all

  15. Investigating the temporal fluctuations in geoelectrical and geochemical signals Jointly measured in a seismic area of Southern Apennine chain (Italy

    Directory of Open Access Journals (Sweden)

    S. Piscitelli

    2001-06-01

    Full Text Available We analyse geoelectrical and geochemical time series jointly measured by means of a multiparametric automatic station close to an anomalous fluid emission in Val d'Agri (Basilicata, Southern Italy. In the investigated are some destructive seismic events occurred in past and recent years. We analysed the temporal fluctuations of the signals by spectral tools. We detected scaling behaviours in the power spectra of the time series recorded, that are typical fingerprints of fractional Brownian motions. The estimated values of the spectral indices reveal the presence of antipersistent behaviour in the time dynamics of all geoelectrical and geochemical data recorded. This work intends to improve our knowledge of the inner time dynamics of geophysical non-seismometric parameters.

  16. Annals of the International Geophysical Year solar radio emission during the International Geophysical Year

    CERN Document Server

    Smerd, S F

    1969-01-01

    Annals of the International Geophysical Year, Volume 34: Solar Radio Emission During the International Geophysical Year covers the significant solar radio emission events observed during the International Geophysical Year (IGY). This book is composed of six chapters, and begins with a summary of tabulated quantities describing solar radio emission during the IGY. The tabulated figures illustrate the method of recording the position of radio sources on the sun, the use of symbols in describing the structure of bursts observed at single frequencies, and the different types used in a spectral

  17. GeoFramework: A Modeling Framework for Solid Earth Geophysics

    Science.gov (United States)

    Gurnis, M.; Aivazis, M.; Tromp, J.; Tan, E.; Thoutireddy, P.; Liu, Q.; Choi, E.; Dicaprio, C.; Chen, M.; Simons, M.; Quenette, S.; Appelbe, B.; Aagaard, B.; Williams, C.; Lavier, L.; Moresi, L.; Law, H.

    2003-12-01

    As data sets in geophysics become larger and of greater relevance to other earth science disciplines, and as earth science becomes more interdisciplinary in general, modeling tools are being driven in new directions. There is now a greater need to link modeling codes to one another, link modeling codes to multiple datasets, and to make modeling software available to non modeling specialists. Coupled with rapid progress in computer hardware (including the computational speed afforded by massively parallel computers), progress in numerical algorithms, and the introduction of software frameworks, these lofty goals of merging software in geophysics are now possible. The GeoFramework project, a collaboration between computer scientists and geoscientists, is a response to these needs and opportunities. GeoFramework is based on and extends Pyre, a Python-based modeling framework, recently developed to link solid (Lagrangian) and fluid (Eulerian) models, as well as mesh generators, visualization packages, and databases, with one another for engineering applications. The utility and generality of Pyre as a general purpose framework in science is now being recognized. Besides its use in engineering and geophysics, it is also being used in particle physics and astronomy. Geology and geophysics impose their own unique requirements on software frameworks which are not generally available in existing frameworks and so there is a need for research in this area. One of the special requirements is the way Lagrangian and Eulerian codes will need to be linked in time and space within a plate tectonics context. GeoFramework has grown beyond its initial goal of linking a limited number of exiting codes together. The following codes are now being reengineered within the context of Pyre: Tecton, 3-D FE Visco-elastic code for lithospheric relaxation; CitComS, a code for spherical mantle convection; SpecFEM3D, a SEM code for global and regional seismic waves; eqsim, a FE code for dynamic

  18. Bayesian Model Selection in Geophysics: The evidence

    Science.gov (United States)

    Vrugt, J. A.

    2016-12-01

    Bayesian inference has found widespread application and use in science and engineering to reconcile Earth system models with data, including prediction in space (interpolation), prediction in time (forecasting), assimilation of observations and deterministic/stochastic model output, and inference of the model parameters. Per Bayes theorem, the posterior probability, , P(H|D), of a hypothesis, H, given the data D, is equivalent to the product of its prior probability, P(H), and likelihood, L(H|D), divided by a normalization constant, P(D). In geophysics, the hypothesis, H, often constitutes a description (parameterization) of the subsurface for some entity of interest (e.g. porosity, moisture content). The normalization constant, P(D), is not required for inference of the subsurface structure, yet of great value for model selection. Unfortunately, it is not particularly easy to estimate P(D) in practice. Here, I will introduce the various building blocks of a general purpose method which provides robust and unbiased estimates of the evidence, P(D). This method uses multi-dimensional numerical integration of the posterior (parameter) distribution. I will then illustrate this new estimator by application to three competing subsurface models (hypothesis) using GPR travel time data from the South Oyster Bacterial Transport Site, in Virginia, USA. The three subsurface models differ in their treatment of the porosity distribution and use (a) horizontal layering with fixed layer thicknesses, (b) vertical layering with fixed layer thicknesses and (c) a multi-Gaussian field. The results of the new estimator are compared against the brute force Monte Carlo method, and the Laplace-Metropolis method.

  19. Overview of geochemical modeling needs for nuclear waste management

    International Nuclear Information System (INIS)

    Isherwood, D.; Wolery, T.

    1984-01-01

    Research needs include, but are not limited to: measurement of basic thermodynamic data at elevated temperatures for species identified by modelers as potentially important; evaluation of substances which control or limit precipitation and/or nucleation kinetics; sorption studies specifically designed to provide data needed for modeling. This includes the rate of sorption, desorption, and the characterization of the solid and aqueous phases; site-mixing models and thermodynamic data for secondary minerals that form solid solutions; the development of standard techniques for measuring rate laws for precipitation and dissolution kinetics; and measurement of rate laws describing redox kinetics, dissolution, and precipitation involving aqueous species and solid phases of interest to geochemical modelers

  20. Development of thermodynamic databases for geochemical calculations

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.C. [Monitor Scientific, L.L.C., Denver, Colorado (United States); Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan); Neyama, Atsushi [Computer Software Development Corp., Tokyo (Japan)

    1999-09-01

    Two thermodynamic databases for geochemical calculations supporting research and development on geological disposal concepts for high level radioactive waste are described in this report. One, SPRONS.JNC, is compatible with thermodynamic relations comprising the SUPCRT model and software, which permits calculation of the standard molal and partial molal thermodynamic properties of minerals, gases, aqueous species and reactions from 1 to 5000 bars and 0 to 1000degC. This database includes standard molal Gibbs free energies and enthalpies of formation, standard molal entropies and volumes, and Maier-Kelly heat capacity coefficients at the reference pressure (1 bar) and temperature (25degC) for 195 minerals and 16 gases. It also includes standard partial molal Gibbs free energies and enthalpies of formation, standard partial molal entropies, and Helgeson, Kirkham and Flowers (HKF) equation-of-state coefficients at the reference pressure and temperature for 1147 inorganic and organic aqueous ions and complexes. SPRONS.JNC extends similar databases described elsewhere by incorporating new and revised data published in the peer-reviewed literature since 1991. The other database, PHREEQE.JNC, is compatible with the PHREEQE series of geochemical modeling codes. It includes equilibrium constants at 25degC and l bar for mineral-dissolution, gas-solubility, aqueous-association and oxidation-reduction reactions. Reaction enthalpies, or coefficients in an empirical log K(T) function, are also included in this database, which permits calculation of equilibrium constants between 0 and 100degC at 1 bar. All equilibrium constants, reaction enthalpies, and log K(T) coefficients in PHREEQE.JNC are calculated using SUPCRT and SPRONS.JNC, which ensures that these two databases are mutually consistent. They are also internally consistent insofar as all the data are compatible with basic thermodynamic definitions and functional relations in the SUPCRT model, and because primary

  1. GEOPHYSICAL AND WELL CORELLATION ANALYSIS OF OGO ...

    African Journals Online (AJOL)

    A suite of geophysical wire line logs were run in hole. The wells data were acquired from bottom to top and not top to bottom. Basically, we have the qualitative and the quantitative evaluation techniques.Qualitative means is usually used for identification of the type of lithology and also for the component of the formation.

  2. Seismic and Geophysical Characterization of Northern Asia

    Science.gov (United States)

    2010-09-01

    SEISMIC AND GEOPHYSICAL CHARACTERIZATION OF NORTHERN ASIA Kevin Mackey1, Hans Hartse2, Kazuya Fujita1, Michael Pasyanos3, and Michael Begnaud2...improve the calibration of northern Asia for nuclear explosion monitoring purposes. This project builds off previous work, and is a cooperative...propagation characteristics in northern Asia . Our work will further improve location and detection and discrimination capabilities, crustal and upper

  3. GEOPHYSICAL INVESTIGATION OF GROUND SUBSIDENCE: A ...

    African Journals Online (AJOL)

    A geophysical investigation involving the electrical resistivity and gravity methods was carried out within the premises of a Beverage Factory in Edo State. The investigation was to enable the determination of the cause(s) of a ground subsidence within the premises of the boilers. The vertical electrical sounding interpretation ...

  4. Geophysical investigations for groundwater in the middle ...

    African Journals Online (AJOL)

    In this study, geophysical investigations were carried out in twelve (12) communities in the Up-per Denkyira District located in the Birimian and the Tarkwaian Formations of the Central Re-gion of Ghana with the aim of delineating groundwater potential zones, drilling the selected sites, and subsequently comparing the ...

  5. Integrated geophysical approach in groundwater exploration of ...

    African Journals Online (AJOL)

    A combined geophysical investigation comprising electromagnetic (EM) and resistivity depth sounding carried out around Gwoza area indicate that the area is suitable for borehole development. The electromagnetic results along six profiles identified five locations that are favorable for detail vertical electrical sounding ...

  6. Hydrogeological and geophysical study for deeper groundwater ...

    Indian Academy of Sciences (India)

    Electrical resistivity method is a versatile and economical technique for groundwater prospecting in different geological settings due to wide spectrum of resistivity compared to other geophysical parameters. Exploration and exploitation of groundwater, a vital and precious resource, is a challenging task in hard rock, which ...

  7. Geophysical Identification of Hydrothermally Altered Structures That ...

    African Journals Online (AJOL)

    This research study uses geophysical method (aeromagnetic) to identify hydrothermally altered structures which favour the inflow of hydrothermal fluid that usually brings about gold mineralisation in Egbe-Isanlu Schist Belt Area, North Central Nigeria. The application of data enhancement filtering algorithm such as ...

  8. Early geophysical maps published by A. Petermann

    Czech Academy of Sciences Publication Activity Database

    Kozák, Jan; Vaněk, Jiří

    2012-01-01

    Roč. 56, č. 4 (2012), s. 1109-1122 ISSN 0039-3169 Institutional research plan: CEZ:AV0Z30120515 Keywords : August Petermann * Geographische Mitteilungen * geophysical maps Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.975, year: 2012

  9. Some geological and geophysical aspects in electric rock breaking

    CSIR Research Space (South Africa)

    Henry, G

    2011-08-01

    Full Text Available This presentation looks at the way rocks break and the geological and geophysical aspects thereof. It it important to know that rocks are much weaker under tension (10 times) than under compression. Geological and geophysical factors play...

  10. A portable marine geophysical data access and management system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Narvekar, P.

    The marine Geophysical Data Access and Management System (GPDAMS) is a portable software system designed for computerized storage, selective retrieval and management of marine geophysical data. It constitutes an integral part of the larger...

  11. Geophysics applications in critical zone science: emerging topics

    Science.gov (United States)

    Geophysical studies have resulted in remarkable advances in characterization of critical zone. The geophysics applications uncover the relationships between structure and function in subsurface as they seek to define subsurface structural units with individual properties of retention and trans...

  12. Robust statistics and geochemical data analysis

    International Nuclear Information System (INIS)

    Di, Z.

    1987-01-01

    Advantages of robust procedures over ordinary least-squares procedures in geochemical data analysis is demonstrated using NURE data from the Hot Springs Quadrangle, South Dakota, USA. Robust principal components analysis with 5% multivariate trimming successfully guarded the analysis against perturbations by outliers and increased the number of interpretable factors. Regression with SINE estimates significantly increased the goodness-of-fit of the regression and improved the correspondence of delineated anomalies with known uranium prospects. Because of the ubiquitous existence of outliers in geochemical data, robust statistical procedures are suggested as routine procedures to replace ordinary least-squares procedures

  13. Coupling of transport and geochemical models

    International Nuclear Information System (INIS)

    Noy, D.J.

    1985-01-01

    This contract stipulated separate pieces of work to consider mass transport in the far-field of a repository, and more detailed geochemical modelling of the groundwater in the near-field. It was envisaged that the far-field problem would be tackled by numerical solutions to the classical advection-diffusion equation obtained by the finite element method. For the near-field problem the feasibility of coupling existing geochemical equilibrium codes to the three dimensional groundwater flow codes was to be investigated. This report is divided into two sections with one part devoted to each aspect of this contract. (author)

  14. Adaptive Multiscale Modeling of Geochemical Impacts on Fracture Evolution

    Science.gov (United States)

    Molins, S.; Trebotich, D.; Steefel, C. I.; Deng, H.

    2016-12-01

    Understanding fracture evolution is essential for many subsurface energy applications, including subsurface storage, shale gas production, fracking, CO2 sequestration, and geothermal energy extraction. Geochemical processes in particular play a significant role in the evolution of fractures through dissolution-driven widening, fines migration, and/or fracture sealing due to precipitation. One obstacle to understanding and exploiting geochemical fracture evolution is that it is a multiscale process. However, current geochemical modeling of fractures cannot capture this multi-scale nature of geochemical and mechanical impacts on fracture evolution, and is limited to either a continuum or pore-scale representation. Conventional continuum-scale models treat fractures as preferential flow paths, with their permeability evolving as a function (often, a cubic law) of the fracture aperture. This approach has the limitation that it oversimplifies flow within the fracture in its omission of pore scale effects while also assuming well-mixed conditions. More recently, pore-scale models along with advanced characterization techniques have allowed for accurate simulations of flow and reactive transport within the pore space (Molins et al., 2014, 2015). However, these models, even with high performance computing, are currently limited in their ability to treat tractable domain sizes (Steefel et al., 2013). Thus, there is a critical need to develop an adaptive modeling capability that can account for separate properties and processes, emergent and otherwise, in the fracture and the rock matrix at different spatial scales. Here we present an adaptive modeling capability that treats geochemical impacts on fracture evolution within a single multiscale framework. Model development makes use of the high performance simulation capability, Chombo-Crunch, leveraged by high resolution characterization and experiments. The modeling framework is based on the adaptive capability in Chombo

  15. Geophysical Investigations in the Caucasus (1925 - 2012): Initial, Basic and Modern Stages

    Science.gov (United States)

    Eppelbaum, L. V.

    2012-04-01

    testing different geophysical methods and methodologies in complicated environments. Airborne magnetic and gravity surveys covered all the Caucasus, regional seismic and magnetotelluric studies were used as reference profiles for deep structure investigation. Numerous effective applications of geophysical methods for searching ore, oil&gas deposits, building raw, fresh water localization, solving engineering, etc. was demonstrated. Seismological investigations (including different methods) were widely applied throughout the entire Caucasian region. Satellite geophysical examinations were successfully combined with other methods. Finally, destruction of the former Soviet Union in 1991 (beginning of the modern stage) caused a sharp common decreasing of the geophysical activity in this region. Only foreign oil-&gas companies (mainly American and England) demonstrated some industrial geophysical activity basically in the Caspian Sea. In the last few years the situation began to straighten out, especially in the field of seismology. This presentation is based of the author's experience (e.g., Eppelbaum, 1989, 1991, 2009; Eppelbaum et al., 1987; Eppelbaum and Finkelstein, 1998; Eppelbaum and Khesin, 1988, 1992, 2002, 2004, 2011, 2012; Eppelbaum and Mishne, 2011; Eppelbaum et al., 2003, 2004; Khesin et al., 1988, 1993a, 1993b, 1996, 1997; Khesin and Eppelbaum, 1986, 1994, 1997, 2007; Pilchin and Eppelbaum, 1997, 2011) and corresponding publications and reviews of other authors.

  16. Atmospheric and Geophysical Sciences Division Program Report, 1988--1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

    In 1990, the Atmospheric and Geophysical Sciences Division begins its 17th year as a division. As the Division has grown over the years, its modeling capabilities have expanded to include a broad range of time and space scales ranging from hours to decades and from local to global. Our modeling is now reaching out from its atmospheric focus to treat linkages with the oceans and the land. In this report, we describe the Division's goal and organizational structure. We also provide tables and appendices describing the Division's budget, personnel, models, and publications. 2 figs., 1 tab.

  17. 25 CFR 211.56 - Geological and geophysical permits.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 211.56 Section 211.56... FOR MINERAL DEVELOPMENT Rents, Royalties, Cancellations and Appeals § 211.56 Geological and geophysical permits. Permits to conduct geological and geophysical operations on Indian lands which do not...

  18. 25 CFR 212.56 - Geological and geophysical permits.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 212.56 Section 212.56... FOR MINERAL DEVELOPMENT Rents, Royalties, Cancellations, and Appeals § 212.56 Geological and geophysical permits. (a) Permits to conduct geological and geophysical operations on Indian lands which do not...

  19. geotechnical examination of the geophysical

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Abstract. This present work was carried out to determine the geotechnical properties of Olokoro lateritic soil. Tests were carried out on the sample soil which includes the Atterberg limit tests, particle size distribution analysis; sedimentation test, compaction test using the West African standard and California ...

  20. An integrated geochemical and geoelectrical Investigation of an ...

    African Journals Online (AJOL)

    Ife Journal of Science ... Geochemical analysis of borehole soil samples for Total Petroleum Hydrocarbon (TPH), geoelectrical imaging and geotechnical sieve analysis were used to assess the ... Keywords: Geochemical Analysis, Geoelectric Imaging, Borehole Sampling, TPH Concentrations, Oil Spill, Contamination ...

  1. NGDC Marine Geophysical Data Systems: Past, Present, and Future

    Science.gov (United States)

    Sharman, G. F.; Divins, D. L.; Metzger, D. R.; Campagnoli, J. G.

    2001-12-01

    For the past quarter century, the National Geophysical Data Center (NGDC) has disseminated marine geophysical data previously submitted to the national archive which NGDC maintains for the scientific community. Beginning in 1977, with a conference of users to establish an exchange format, GEODAS(GEOphysical DAta System) has been a tool for describing, distributing, and exchanging marine geophysical data. In the last decade CD-ROM technology permitted distribution of entire databases along with GEODAS software. Described in Sharman, et al., Surveying and Land Information Systems, 58,3(1998)pp.141-146, GEODAS is an integrated, home-grown system developed to address a particular class of data in the absence of Commercial Off-The-Shelf (COTS) solutions. GEODAS has evolved to index the location and quality of multibeam data as well as providing a 1-minute, vertical beam derivative for those who did not wish to deal with the full array of data. NGDC's Coastal Relief Model (CRM) and Global Relief (ETOPO2) are also delivered with the GEODAS software as the primary management tool. The CRM represents a new evolution of NGDC data practice, delivering a gridded data product derived from, rather than, the primary data. Customer-demand for data easily imported into increasingly popular Geographic Information Systems(GIS) drove this change. Our delivery of the CRM includes "canned" graphic images with a web-structured CD-ROM delivery accessed by Web browsers, thus allowing COTS solutions for multi-platform access. GEODAS software permits resampling, joining, and otherwise reformatting the data for export. Future developments include two proposals to deliver high volume data sets (e.g. multibeam, and acoustic imagery/side scan) and data in a spatially enabled format via the Web. Both will begin using COTS solutions that accommodate the needs of a specialized MGG community and their data. Future directions include increasing use of COTS packages, when applicable, to manage and

  2. Appliance of geochemical engineering in radioactive waste disposal

    International Nuclear Information System (INIS)

    Li Shuang; Zhang Chengjiang; Ni Shijun; Li Kuanliang

    2008-01-01

    The basic foundation of applying geochemical engineering to control environment, common engineering models of disposal radioactive waste and the functions of the engineering barriers are introduced in this paper. The authors take the geochemical engineering barrier materiel research of a radioactive waste repository as an example to explain the appliance of geochemical engineering in the disposal of radioactive waste. And the results show that it can enhance the security of the nuclear waste repository if we use geochemical engineering barrier. (authors)

  3. Geochemical assessment of fluoride enrichment and nitrate ...

    Indian Academy of Sciences (India)

    62

    minerals. By reducing the consumption of fertilizer and stress over groundwater, the water quality can be improved. Key Word- Hydro-geochemistry, Fluoride, ... source (industries effluent, fertilizer industry and fertilizer used in agriculture field) influences ...... groundwater of the Taiyuan basin, Northern China; J. Geochem.

  4. Geochemical fingerprints and pebbles zircon geochronology

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 7. Geochemical fingerprints and pebbles zircon geochronology: Implications for the provenance and tectonic setting of Lower Cretaceous sediments in the Zhucheng Basin (Jiaodong peninsula, North China). Jin-Long Ni Jun-Lai Liu Xiao-Ling Tang ...

  5. Kriging - a challenge in geochemical mapping

    Czech Academy of Sciences Publication Activity Database

    Štojdl, J.; Matys Grygar, Tomáš; Elznicová, J.; Popelka, J.; Váchová, T.; Hošek, Michal

    2017-01-01

    Roč. 19, APR (2017) ISSN 1607-7962. [EGU General Assembly 2017. 23.04.2017-28.04.2017, Vienna] Institutional support: RVO:61388980 Keywords : kriging * geochemical mapping Subject RIV: DD - Geochemistry http://meetingorganizer. copernicus .org/EGU2017/EGU2017-3615.pdf

  6. Discriminating four tectonic settings: Five new geochemical ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 115; Issue 5. Discriminating four tectonic settings: Five new geochemical diagrams for basic and ultrabasic volcanic rocks based on log–ratio transformation of major-element data. Surendra P Verma Mirna Guevara Salil Agrawal. Volume 115 Issue 5 October 2006 ...

  7. Association between physical and geochemical characteristics of ...

    African Journals Online (AJOL)

    ... as well as in waters relatively rich in uranium, rubidium, vanadium and manganese. It was clear that the occurrence of algae coincided with specific geological formations. These algae could act as indicator species of geology and heavy metals. Keywords: thermal springs, Limpopo Province, algae, diversity, geochemical ...

  8. Geophysical methods for road construction and maintenance

    Science.gov (United States)

    Rasul, Hedi; Karlson, Caroline; Jamali, Imran; Earon, Robert; Olofsson, Bo

    2015-04-01

    Infrastructure, such as road transportation, is a vital in civilized societies; which need to be constructed and maintained regularly. A large part of the project cost is attributed to subsurface conditions, where unsatisfactory conditions could increase either the geotechnical stabilization measures needed or the design cost itself. A way to collect information of the subsurface and existing installations which can lead to measures reducing the project cost and damage is to use geophysical methods during planning, construction and maintenance phases. The moisture in road layers is an important factor, which will affect the bearing capacity of the construction as well as the maintenances. Moisture in the road is a key factor for a well-functioning road. On the other hand the excessive moisture is the main reason of road failure and problems. From a hydrological point of view geophysical methods could help road planners identify the water table, geological strata, pollution arising from the road and the movement of the pollution before, during and after construction. Geophysical methods also allow road planners to collect valuable data for a large area without intrusive investigations such as with boreholes, i.e. minimizing the environmental stresses and costs. However, it is important to specify the investigation site and to choose the most appropriate geophysical method based on the site chosen and the objective of the investigation. Currently, numerous construction and rehabilitation projects are taking places around the world. Many of these projects are focused on infrastructural development, comprising both new projects and expansion of the existing infrastructural network. Geophysical methods can benefit these projects greatly during all phases. During the construction phase Ground Penetrating radar (GPR) is very useful in combination with Electrical Resistivity (ER) for detecting soil water content and base course compaction. However, ER and Electromagnetic

  9. Geologic and geochemical studies of the New Albany Shale Group (Devonian-Mississippian) in Illinois. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bergstrom, R.E.; Shimp, N.F.

    1980-06-30

    The Illinois State Geological Survey is conducting geological and geochemical investigations to evaluate the potential of New Albany Group shales as a source of hydrocarbons, particularly natural gas. Geological studies include stratigraphy and structure, mineralogic and petrographic characterization; analyses of physical properties; and development of a computer-based resources evaluation system. Geochemical studies include organic carbon content and trace elements; hydrocarbon content and composition; and adsorption/desorption studies of gas through shales. Separate abstracts have been prepared for each task reported.

  10. The Global Geophysical Fluids Center of IERS (and its Special Bureau for Mantle)

    Science.gov (United States)

    Chao, B. F.

    2002-12-01

    The Global Geophysical Fluids Center (GGFC) was established by the International Earth Rotation Service (IERS) on IERS's 10th anniversary day January 1, 1998, in an effort to expand IERS's services to the scientific community. Under the GGFC, eight Special Bureaus (SB) have been selected, each to be responsible for research and data service activities pertaining to mass transports and related geophysical processes in specific components of the Earth system, or "global geophysical fluids," including the atmosphere, oceans, solid Earth, core, and geophysical processes of gravity, loading, tides and hydrological cycles. GGFC and the SBs have the responsibility of supporting, facilitating, and providing services to the worldwide research community, in areas related to the variations in Earth rotation, gravity field and geocenter that are caused by mass transport in the global geophysical fluids. These minute variations have been observed by various space geodetic techniques, as effective remote sensing tools, with ever increasing precision/accuracy and temporal/spatial resolution. The GGFC and SBs have organized dedicated workshops and special sessions at international conferences, published articles, and held regular business meetings. The SBs maintain individual website for data services and information exchanges. See URL bowie.gsfc.nasa.gov/ggfc/. In particular, the SB for Mantle focuses on large-scale mass redistributions that occur in the mantle in association with various dynamic processes, including seismic activities, the post-glacial rebound, and mantle convections.

  11. Geochemical characteristics and organic carbon sources within the ...

    Indian Academy of Sciences (India)

    This paper uses C isotopic methods coupled with other geochemical parameters to investigate differences in the geochemical characteristics and sources of organic C within the Nanpan and Beipan rivers, two upstream tributaries to the Xi River. 2. Geographic, hydrologic, and geochemical setting. The Nanpan and Beipan ...

  12. Compilation of kinetic data for geochemical calculations

    International Nuclear Information System (INIS)

    Arthur, R.C.; Savage, D.; Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu

    2000-01-01

    Kinetic data, including rate constants, reaction orders and activation energies, are compiled for 34 hydrolysis reactions involving feldspars, sheet silicates, zeolites, oxides, pyroxenes and amphiboles, and for similar reactions involving calcite and pyrite. The data are compatible with a rate law consistent with surface reaction control and transition-state theory, which is incorporated in the geochemical software package EQ3/6 and GWB. Kinetic data for the reactions noted above are strictly compatible with the transition-state rate law only under far-from-equilibrium conditions. It is possible that the data are conceptually consistent with this rate law under both far-from-equilibrium and near-to-equilibrium conditions, but this should be confirmed whenever possible through analysis of original experimental results. Due to limitations in the availability of kinetic data for mine-water reactions, and in order to simplify evaluations of geochemical models of groundwater evolution, it is convenient to assume local-equilibrium in such models whenever possible. To assess whether this assumption is reasonable, a modeling approach accounting for couple fluid flow and water-rock interaction is described that can be use to estimate spatial and temporal scale of local equilibrium. The approach is demonstrated for conditions involving groundwater flow in fractures at JNC's Kamaishi in-situ tests site, and is also used to estimate the travel time necessary for oxidizing surface waters to migrate to the level of a HLW repository in crystalline rock. The question of whether local equilibrium is a reasonable assumption must be addressed using an appropriate modeling approach. To be appropriate for conditions at the Kamaishi site using the modeling approach noted above, the fracture fill must closely approximate a porous mine, groundwater flow must be purely advective and diffusion of solutes across the fracture-host rock boundary must not occur. Moreover, the mineralogical and

  13. Compilation of kinetic data for geochemical calculations

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.C. [Monitor Scientific, LLC., Denver, Colorado (United States); Savage, D. [Quintessa, Ltd., Nottingham (United Kingdom); Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works

    2000-01-01

    Kinetic data, including rate constants, reaction orders and activation energies, are compiled for 34 hydrolysis reactions involving feldspars, sheet silicates, zeolites, oxides, pyroxenes and amphiboles, and for similar reactions involving calcite and pyrite. The data are compatible with a rate law consistent with surface reaction control and transition-state theory, which is incorporated in the geochemical software package EQ3/6 and GWB. Kinetic data for the reactions noted above are strictly compatible with the transition-state rate law only under far-from-equilibrium conditions. It is possible that the data are conceptually consistent with this rate law under both far-from-equilibrium and near-to-equilibrium conditions, but this should be confirmed whenever possible through analysis of original experimental results. Due to limitations in the availability of kinetic data for mine-water reactions, and in order to simplify evaluations of geochemical models of groundwater evolution, it is convenient to assume local-equilibrium in such models whenever possible. To assess whether this assumption is reasonable, a modeling approach accounting for couple fluid flow and water-rock interaction is described that can be use to estimate spatial and temporal scale of local equilibrium. The approach is demonstrated for conditions involving groundwater flow in fractures at JNC's Kamaishi in-situ tests site, and is also used to estimate the travel time necessary for oxidizing surface waters to migrate to the level of a HLW repository in crystalline rock. The question of whether local equilibrium is a reasonable assumption must be addressed using an appropriate modeling approach. To be appropriate for conditions at the Kamaishi site using the modeling approach noted above, the fracture fill must closely approximate a porous mine, groundwater flow must be purely advective and diffusion of solutes across the fracture-host rock boundary must not occur. Moreover, the

  14. Geochemical baseline studies of soil in Finland

    Science.gov (United States)

    Pihlaja, Jouni

    2017-04-01

    The soil element concentrations regionally vary a lot in Finland. Mostly this is caused by the different bedrock types, which are reflected in the soil qualities. Geological Survey of Finland (GTK) is carrying out geochemical baseline studies in Finland. In the previous phase, the research is focusing on urban areas and mine environments. The information can, for example, be used to determine the need for soil remediation, to assess environmental impacts or to measure the natural state of soil in industrial areas or mine districts. The field work is done by taking soil samples, typically at depth between 0-10 cm. Sampling sites are chosen to represent the most vulnerable areas when thinking of human impacts by possible toxic soil element contents: playgrounds, day-care centers, schools, parks and residential areas. In the mine districts the samples are taken from the areas locating outside the airborne dust effected areas. Element contents of the soil samples are then analyzed with ICP-AES and ICP-MS, Hg with CV-AAS. The results of the geochemical baseline studies are published in the Finnish national geochemical baseline database (TAPIR). The geochemical baseline map service is free for all users via internet browser. Through this map service it is possible to calculate regional soil baseline values using geochemical data stored in the map service database. Baseline data for 17 elements in total is provided in the map service and it can be viewed on the GTK's web pages (http://gtkdata.gtk.fi/Tapir/indexEN.html).

  15. Geochemical Signature of Amazon Tropical Rainforest Soils

    Directory of Open Access Journals (Sweden)

    José João Lelis Leal de Souza

    2018-02-01

    Full Text Available ABSTRACT: Evaluating soil geochemical diversity in the Amazon Basin has been a challenge largely because most study sites have been at the edge of the basin and it is difficult to get samples in such a region. Here we show that even among the most weathered soils, physicochemical soil properties express lithology. Our results are based on topsoil samples collected from different locations in minimally disturbed areas in the state of Amazonas, Brazil. Soil properties were measured using methods which are suitable for highly developed soils. The Chemical Index Alteration and Weathering Index of Parker was calculated based on the content of metal(loids in soils determined by X-ray fluorescence. Descriptive statistics, Pearson correlation, and Principal Component Analysis (PCA were performed on data. In general, Amazon rainforest soils are more deeply weathered than soils in other Brazilian biomes and tropical rainforests in Asia and Africa. The high coefficient of variation of metal(loid contents express pedogenesis and parent material diversity. Correlation analysis indicated that the tri-pentavalent elements are strongly associated with Al and Fe contents in the topsoil. In contrast, mono-divalent elements are correlated with sand and silt fractions. According to PCA, five soil groups with defined geochemical compositions and degrees of weathering could be identified: i acidic sandy podzolized soils; ii acidic loamy ferralitic soils with the highest content of tri-pentavalent ions; iii acidic clayey kaolinitic soils with low metal(loid contents; iv acidic loamy kaolinitic soils with low metal(loid contents; and v silty neutral 2:1 clay soils. This study is the first effort to analyze the geochemical diversity in Amazon rainforest soils. These data are extremely valuable in determining the geochemical background for these soil types and this region. Geochemical variability can be predicted to some extent by lithology and pedogenesis, which can be

  16. Alligator Rivers Analogue project. Geochemical Data Bases

    International Nuclear Information System (INIS)

    Bennett, D.G.; Read, D.

    1992-01-01

    The Koongarra uranium deposit in the Northern Territory of Australia is being studied to evaluate the processes involved in the geochemical alteration of the ore body and the formation of the uranium dispersion fan. A broad range of research is being undertaken into the geochemistry and hydrology of the site with the aim of understanding the transport of radionuclides through the system. During the project a range of geochemical and hydrogeochemical models have been developed to account for measured data from the site and with which to predict site evolution. The majority of these models are based on the premise of thermodynamic chemical equilibrium and employ fundamental thermodynamic data to characterise the chemistry of the system. From the differences which exist between the thermodynamic data bases (Appendices I and II) it is possible to gain a view of the level of uncertainty associated with thermodynamic data in each set of calculations. This report gives a brief introduction to the geochemical processes underlying the models, and details the equations used to quantify the more common of these processes (e.g. aqueous speciation and mineral solubility). A description is given of the computer codes (EQ3/6, PHREEQE, MINTEQ) most commonly used during the project for geochemical modelling. Their key features are highlighted and comparisons made. It is concluded that the degree of uncertainty in geochemical modelling studies arising as a result of using one code rather than another is relatively insignificant when compared to that related to differences in the underlying data bases. 73 refs., 3 figs

  17. Geochemical modelling: what phenomena are missing

    International Nuclear Information System (INIS)

    Jacquier, P.

    1989-12-01

    In the framework of safety assessment of radioactive waste disposal, retention phenomena are usually taken into account by the Kd concept. It is well recognized that this concept is not enough for safety assessment models, because of the several and strong assumptions which are involved in this kind of representation. One way to have a better representation of the retention phenomena, is to substitute for this Kd concept an explicit description of geochemical phenomena and then couple transport codes with geochemical codes in a fully or a two-step procedure. We use currently such codes, but the scope of this paper is to display the limits today of the geochemical modelling in connection with sites analysis for deep disposal. In this paper, we intend to give an overview of phenomena which are missing in the geochemical models, or which are not completely introduced in the models. We can distinguish, on one hand phenomena for which modelling concepts exist such as adsorption/desorption and, on the other hand, phenomena for which modelling concepts do not exist for the moment such as colloids, and complexation by polyelectrolyte solutions (organics). Moreover we have to take care of very low concentrations of radionuclides, which can be expected from the leaching processes in the repository. Under those conditions, some reactions may not occur. After a critical review of the involved phenomena, we intend to stress the main directions of the wishful evolution of the geochemical modelling. This evolution should improve substantially the quality of the above-mentioned site assessments

  18. Planetary Geology and Geophysics Program

    Science.gov (United States)

    McGill, George E.

    2004-01-01

    Geological mapping and topical studies, primarily in the southern Acidalia Planitia/Cydonia Mensae region of Mars is presented. The overall objective was to understand geologic processes and crustal history in the northern lowland in order to assess the probability that an ocean once existed in this region. The major deliverable is a block of 6 1:500,000 scale geologic maps that will be published in 2004 as a single map at 1:1,000,000 scale along with extensive descriptive and interpretive text. A major issue addressed by the mapping was the relative ages of the extensive plains of Acidalia Planitia and the knobs and mesas of Cydonia Mensae. The mapping results clearly favor a younger age for the plains. Topical studies included a preliminary analysis of the very abundant small domes and cones to assess the possibility that their origins could be determined by detailed mapping and remote-sensing analysis. We also tested the validity of putative shorelines by using GIs to co-register full-resolution MOLA altimetry data and Viking images with these shorelines plotted on them. Of the 3 proposed shorelines in this area, one is probably valid, one is definitely not valid, and the third is apparently 2 shorelines closely spaced in elevation. Publications supported entirely or in part by this grant are included.

  19. Geophysical field disturbances and quantum mechanics

    Science.gov (United States)

    Kuznetsov, Vladimir

    2017-10-01

    Quantum processes impact into physics of geophysical field disturbances is discussed here in examples of phenomena such as an earthquake with processes preceding and accompanying it, volcanoes eruptions and diamond exploding pipes. Physics of shock waves generation in ionosphere and atmosphere, mechanism of atmosphere phenomena in supercooled clouds recorded by a stormglass is considered. The report treats of physics of ball and dark lightning, of generating in atmosphere the high-energy particles involved in sprites occurrence, and so on. Geophysical phenomena considered here have no clear and consistent interpretation in the context of classical physics. We attempt to involve the recent achievements of quantum physics namely the quantum entanglement between elementary particles implicated in considered phenomena.

  20. Geophysical and atmospheric evolution of habitable planets.

    Science.gov (United States)

    Lammer, Helmut; Selsis, Frank; Chassefière, Eric; Breuer, Doris; Griessmeier, Jean-Mathias; Kulikov, Yuri N; Erkaev, Nikolai V; Khodachenko, Maxim L; Biernat, Helfried K; Leblanc, Francois; Kallio, Esa; Lundin, Richard; Westall, Frances; Bauer, Siegfried J; Beichman, Charles; Danchi, William; Eiroa, Carlos; Fridlund, Malcolm; Gröller, Hannes; Hanslmeier, Arnold; Hausleitner, Walter; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Léger, Alain; Leitzinger, Martin; Lichtenegger, Herbert I M; Liseau, René; Lunine, Jonathan; Motschmann, Uwe; Odert, Petra; Paresce, Francesco; Parnell, John; Penny, Alan; Quirrenbach, Andreas; Rauer, Heike; Röttgering, Huub; Schneider, Jean; Spohn, Tilman; Stadelmann, Anja; Stangl, Günter; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

    2010-01-01

    The evolution of Earth-like habitable planets is a complex process that depends on the geodynamical and geophysical environments. In particular, it is necessary that plate tectonics remain active over billions of years. These geophysically active environments are strongly coupled to a planet's host star parameters, such as mass, luminosity and activity, orbit location of the habitable zone, and the planet's initial water inventory. Depending on the host star's radiation and particle flux evolution, the composition in the thermosphere, and the availability of an active magnetic dynamo, the atmospheres of Earth-like planets within their habitable zones are differently affected due to thermal and nonthermal escape processes. For some planets, strong atmospheric escape could even effect the stability of the atmosphere.

  1. Geochemical investigation of UMTRAP designated site at Durango, Colorado

    International Nuclear Information System (INIS)

    Markos, G.; Bush, K.J.

    1983-09-01

    This report is the result of a geochemical investigation of the former uranium mill and tailings site at Durango, Colorado. This is one in a series of site specific geochemical investigations performed on the inactive uranium mill tailings included in the UMTRA Project. The objectives of the investigation are to characterize the geochemistry, to determine the contaminant distribution resulting from the former milling activities and tailings, and to infer chemical pathways and transport mechanisms from the contaminant distribution. The results will be used to model contaminant migration and to develop criteria for long-term containment media such as a cover system which is impermeable to contaminant migration. This report assumes a familiarity with the hydrologic conditions of the site and the geochemical concepts underlying the investigation. The results reported are based on a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. The solid samples are water extracted remove easily soluble salts and acids extracted to remove cabonates and hydroxides. The water extracts and solid samples were analyzed for the major and trace elements. A limited number of samples were analyzed for radiological components. The report includes the methods of sampling, sample processing, analysis, and data interpretation. Three major conclusions are: (1) carbonate salts and low TDS characterize the tailings; (2) the adjacent area and raffinate ponds contain contaminants deposited by a single event of fluid permeation of the soils; and (3) the Animas River adjacent to the site has elevated gross alpha activity attributed to 226 Ra in the sediments derived from the tailings or milling activities

  2. Development of thermodynamic databases and geochemical/transport models for prediction of long-term radionuclide migration (Germany)

    International Nuclear Information System (INIS)

    Kienzler, B.

    2000-01-01

    The isolation capacity of a repository system for radionuclides is described by geochemical modeling. The models for interpretation of experimental findings and for long-term extrapolation of experimental results are based on thermodynamic approaches. The geochemical models include dissolution reactions of waste forms, the evolution of the geochemical milieu, interactions of radionuclides with constituents of the groundwater (brines) and the precipitation of new solid phases. Reliable thermodynamic data, understanding of radionuclide complexation in aqueous multi-electrolyte solutions at the relevant ionic strength and knowledge on the formation of pure and mixed solids and on sorption processes are urgently needed for such model calculations. (author)

  3. Geophysical Methods for Non-Destructive Testing in Civil Engineering

    Science.gov (United States)

    Niederleithinger, E.

    2013-12-01

    Many non-destructive testing (NDT) methods for civil engineering (e. g. ultrasonics, radar) are similar to geophysical techniques. They just differ in scale, material under investigation and vocabulary used. In spite of the fact that the same principles of physics and mathematics apply to both fields, exchange has been limited in the past. But since a few years more and more geophysical knowledge is used in civil engineering. One of the focal points in research is to improve ultrasonic testing of concrete to be able to image the inside even of large, complex structures and to detect any deterioration as early as possible. One of the main issues is the heterogeneity of concrete, including aggregates, reinforcement, cracks and many other features. Our current research focuses on three points. One is the application of state of the art geophysical migration techniques as Reverse Time Migration (RTM) to image vertical faces or the backside of voids and ducts in thick concrete structures, which isn't possible with conventional techniques used in NDT. Second, we have started to use seismic interferometric techniques to interpolate ultrasonic traces, which can't be measured directly for technical reasons. Third, we are using coda wave interferometry to detect concrete degradation due to load, fatigue, temperature or other influences as early as possible. Practical examples of the application of these techniques are given and potential future research directions will be discussed. It will be shown, how a subset of these techniques can be used for innovative monitoring systems for civil infrastructure. Imaging the interior of a concrete body by ultrasonics and reverse time migration(simulated data).

  4. Geophysical Fluid Flow Cell (GFFC) Simulation

    Science.gov (United States)

    1999-01-01

    These simulations of atmospheric flow use the same experimental parameters but started with slightly different initial conditions in the model. The simulations were part of data analysis for the Geophysical Fluid Flow Cell (GFFC), a planet in a test tube apparatus flown on Spacelab to mimic the atmospheres on gas giant planets and stars. (Credit: Dr. Tim Miller of Global Hydrology and Climate Center at the Marshall Space Flight Center)

  5. Airborne geophysics in Australia: the government contribution

    International Nuclear Information System (INIS)

    Denham, D.

    1997-01-01

    Airborne geophysical data sets provide important cost-effective information for resource exploration and land management. Improved techniques, developed recently, now enable high-resolution aeromagnetic and gamma-ray surveys to be used extensively by the resource industries to improve the cost effectiveness of exploration and by governments to encourage resource development and sustainable management of natural resources. Although airborne geophysical techniques have been used extensively and are now used almost routinely by mineral explorers, it is only in the last few years that governments have been involved as major players in the acquisition of data. The exploration industry pioneered the imaging of high-resolution airborne geophysical data sets in the early 1980s and, at the same time, the Northern Territory Government started a modest program of flying the Northern Territory, at 500 m flight-line spacing, to attract mineral exploration. After the start of the National Geoscience Mapping Accord in 1990, the then BMR and its State/Territory counterparts used the new high-resolution data as an essential ingredient to underpin mapping programs. These new data sets proved so valuable that, starting in 1992/93, the annual expenditure by the Commonwealth and States/Northern Territory increased from roughly $2 million per year to a massive $10 million per year. These investments by governments, although unlikely to be permanently sustainable, have been made to encourage and expand exploration activity by providing new high-quality data sets in industry at very low cost. There are now approximately 11 million line-km of airborne geophysical data available in databases held by the Commonwealth, States and Northern Territory. The results so far have seen a significant increase in exploration activity in States that have embarked on this course (e.g. South Australia and Victoria), and the information provided from these surveys is proving crucial to understanding the

  6. GEOPHYSICAL INVESTIGATION OF MARBLE OCCURRENCE IN ...

    African Journals Online (AJOL)

    The outline of the deposit and its plunge direction were confirmed by drilling from which borehole logs show marble thicknesses of 1.3-2.7m at the edges and 16.0 and 19.6m within the marble outlined zone. KeyWords: Marble, Abuja, geophysical investigation, Plunge. [Global Jnl Geol. Sci. Vol.1(1) 2003: 51-62] ...

  7. Symmetries in geology and geophysics

    OpenAIRE

    Turcotte, Donald L.; Newman, William I.

    1996-01-01

    Symmetries have played an important role in a variety of problems in geology and geophysics. A large fraction of studies in mineralogy are devoted to the symmetry properties of crystals. In this paper, however, the emphasis will be on scale-invariant (fractal) symmetries. The earth’s topography is an example of both statistically self-similar and self-affine fractals. Landforms are also associated with drainage networks, which are statistical fractal trees. A unive...

  8. Application of geophysical methods for fracture characterization

    International Nuclear Information System (INIS)

    Lee, K.H.; Majer, E.L.; McEvilly, T.V.; California Univ., Berkeley, CA; Morrison, H.F.; California Univ., Berkeley, CA

    1990-01-01

    One of the most crucial needs in the design and implementation of an underground waste isolation facility is a reliable method for the detection and characterization of fractures in zones away from boreholes or subsurface workings. Geophysical methods may represent a solution to this problem. If fractures represent anomalies in the elastic properties or conductive properties of the rocks, then the seismic and electrical techniques may be useful in detecting and characterizing fracture properties. 7 refs., 3 figs

  9. Geophysical fluid dynamics: whence, whither and why?

    Science.gov (United States)

    Vallis, Geoffrey K

    2016-08-01

    This article discusses the role of geophysical fluid dynamics (GFD) in understanding the natural environment, and in particular the dynamics of atmospheres and oceans on Earth and elsewhere. GFD, as usually understood, is a branch of the geosciences that deals with fluid dynamics and that, by tradition, seeks to extract the bare essence of a phenomenon, omitting detail where possible. The geosciences in general deal with complex interacting systems and in some ways resemble condensed matter physics or aspects of biology, where we seek explanations of phenomena at a higher level than simply directly calculating the interactions of all the constituent parts. That is, we try to develop theories or make simple models of the behaviour of the system as a whole. However, these days in many geophysical systems of interest, we can also obtain information for how the system behaves by almost direct numerical simulation from the governing equations. The numerical model itself then explicitly predicts the emergent phenomena-the Gulf Stream, for example-something that is still usually impossible in biology or condensed matter physics. Such simulations, as manifested, for example, in complicated general circulation models, have in some ways been extremely successful and one may reasonably now ask whether understanding a complex geophysical system is necessary for predicting it. In what follows we discuss such issues and the roles that GFD has played in the past and will play in the future.

  10. Geochemical engineering problem identification and program description. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crane, C.H.; Kenkeremath, D.C.

    1981-05-01

    The Geochemical Engineering Program has as its goal the improvement of geochemical fluid management techniques. This document presents the strategy and status of the Geochemical Engineering Program. The magnitude and scope of geochemical-related problems constraining geothermal industry productivity are described. The goals and objectives of the DGE Geochemical Engineering Program are defined. The rationale and strategy of the program are described. The structure, priorities, funding, and management of specific elements within the program are delineated, and the status of the overall program is presented.

  11. Paleoproterozoic snowball earth: extreme climatic and geochemical global change and its biological consequences

    Science.gov (United States)

    Kirschvink, J. L.; Gaidos, E. J.; Bertani, L. E.; Beukes, N. J.; Gutzmer, J.; Maepa, L. N.; Steinberger, R. E.

    2000-01-01

    Geological, geophysical, and geochemical data support a theory that Earth experienced several intervals of intense, global glaciation ("snowball Earth" conditions) during Precambrian time. This snowball model predicts that postglacial, greenhouse-induced warming would lead to the deposition of banded iron formations and cap carbonates. Although global glaciation would have drastically curtailed biological productivity, melting of the oceanic ice would also have induced a cyanobacterial bloom, leading to an oxygen spike in the euphotic zone and to the oxidative precipitation of iron and manganese. A Paleoproterozoic snowball Earth at 2.4 Giga-annum before present (Ga) immediately precedes the Kalahari Manganese Field in southern Africa, suggesting that this rapid and massive change in global climate was responsible for its deposition. As large quantities of O(2) are needed to precipitate this Mn, photosystem II and oxygen radical protection mechanisms must have evolved before 2.4 Ga. This geochemical event may have triggered a compensatory evolutionary branching in the Fe/Mn superoxide dismutase enzyme, providing a Paleoproterozoic calibration point for studies of molecular evolution.

  12. Near-Surface Geophysics: Advancing Earth Science Through Advances in Imaging

    Science.gov (United States)

    Knight, R.

    2006-05-01

    The near-surface of Earth (the top ~100 m) is the region that supports human infrastructure, provides water and mineral resources, and is the interface between solid Earth and atmosphere for many of the biogeochemical cycles that sustain life. Developing an understanding of the processes and properties that occur here is essential for advancing our understanding of many parts of the Earth system. Yet our ability to study, sample, or probe this zone is remarkably primitive. Many investigations rely on drilling, trenching, and direct sampling. But given the pervasive spatial heterogeneity of the region, such methods yield information that is inadequate in terms of the spatial extent and density of sampling. As a result, the Earth science community is turning to geophysical imaging. The area of research that is focused on developing and applying geophysical methods to study this region of Earth is referred to as near-surface geophysics. Near-surface geophysics, as an area of research, includes many types of research, and many types of researchers. Some researchers are drawn to near-surface geophysics due to an interest in specific properties, processes, or applications, which can range from applied to basic science. As examples, near-surface geophysical methods are used for resource exploration and extraction, for the characterization of contaminated sites, for the assessment and design of built infrastructure; and to address scientific questions in neotectonics, volcanology, glaciology, hydrology, sedimentology, archaeology, geochemistry and biogeochemistry. Other researchers are drawn to near-surface geophysics due to an interest in the science of imaging as the driving scientific question. Advances in imaging require investigating the ways in which physical sensors can (or cannot) capture the complexity of a natural system, determining how best to quantify and enhance the spatial and temporal resolution of a measurement, developing new methods for the inversion of

  13. The use of surface geophysical techniques to detect fractures in bedrock; an annotated bibliography

    Science.gov (United States)

    Lewis, Mark R.; Haeni, F.P.

    1987-01-01

    This annotated bibliography compiles references about the theory and application of surface geophysical techniques to locate fractures or fracture zones within bedrock units. Forty-three publications are referenced, including journal articles, theses, conference proceedings, abstracts, translations, and reports prepared by private contractors and U.S. Government agencies. Thirty-one of the publications are annotated. The remainder are untranslated foreign language articles, which are listed only as bibliographic references. Most annotations summarize the location, geologic setting, surface geophysical technique used, and results of a study. A few highly relevant theoretical studies are annotated also. Publications that discuss only the use of borehole geophysical techniques to locate fractures are excluded from this bibliography. Also excluded are highly theoretical works that may have little or no known practical application.

  14. Investigations into near-real-time surveying for geophysical data collection using an autonomous ground vehicle

    Science.gov (United States)

    Phelps, Geoffrey A.; Ippolito, C.; Lee, R.; Spritzer, R.; Yeh, Y.

    2014-01-01

    The U.S. Geological Survey and the National Aeronautics and Space Administration are cooperatively investigating the utility of unmanned vehicles for near-real-time autonomous surveys of geophysical data collection. Initially focused on unmanned ground vehicle collection of magnetic data, this cooperative effort has brought unmanned surveying, precision guidance, near-real-time communication, on-the-fly data processing, and near-real-time data interpretation into the realm of ground geophysical surveying, all of which offer advantages over current methods of manned collection of ground magnetic data. An unmanned ground vehicle mission has demonstrated that these vehicles can successfully complete missions to collect geophysical data, and add advantages in data collection, processing, and interpretation. We view the current experiment as an initial phase in further unmanned vehicle data-collection missions, including aerial surveying.

  15. Demonstration of a Fractured Rock Geophysical Toolbox (FRGT) for Characterization and Monitoring of DNAPL Biodegradation in Fractured Rock Aquifers

    Science.gov (United States)

    2016-01-01

    USER’S GUIDE Demonstration of a Fractured Rock Geophysical Toolbox (FRGT) for Characterization and Monitoring of DNAPL Biodegradation in...Fractured Rock Aquifers ESTCP Project ER-201118 JANUARY 2016 F.D. Day-Lewis C.D. Johnson U. S. Geological Survey, Office of Groundwater...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 01/01/2016 Guidance July 2011 - January 2016 Demonstration of a Fractured Rock Geophysical

  16. Determination of the Geothermal Potential by Geophysical Investigations in the Karbinci-Tarinci Area, in the Vicinity of Shtip

    International Nuclear Information System (INIS)

    Petrov, Goshe; Panovska, Sanja; Delipetrov, Marjan; Dimov, Gjorgji; Jovanovski, Vlatko

    2005-01-01

    Geophysical methods used in the determination of geothermal potential by geophysical investigations in the Karbinci-Tarinci area included as follows: detailed reflective seismic scanning, geomagnetic profiling, geo electric probe and electromagnetic VLF prospecting. The site investigated consists of rocks of Precambrian, Mesozoic (Jurassic), Tertiary (Paleogene Neogene) and Quaternary age. From earlier investigations carried out in the wider vicinity and from investigations carried out by the present authors, one can expect occurrence geothermal water in the area. (Author)

  17. Geophysical Surveys of a Known Karst Feature, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Doll, W.E.; Nyquist, J.E.; Carpenter, P.J.; Kaufmann, R.D.; Carr, B.J.

    1998-01-01

    Geophysical data were acquired at a site on the Oak Ridge Reservation, Tennessee to determine the characteristics of a mud-filled void and to evaluate the effectiveness of a suite of geophysical methods at the site. Methods that were used included microgravity, electrical resistivity, and seismic refraction. Both microgravity and resistivity were able to detect the void as well as overlying structural features. The seismic data provide bedrock depth control for the other two methods, and show other effects that are caused by the void

  18. Computer-based system for processing geophysical data obtained from boreholes

    International Nuclear Information System (INIS)

    Richter, J.M.

    1982-01-01

    A diverse set of computer programs has been developed at the Lawrence Livermore National Laboratory (LLNL) to process geophysical data obtained from boreholes. These programs support such services as digitizing analog records, reading and processing raw data, cataloging and storing processed data, retrieving selected data for analysis, and generating data plots on several different devices. A variety of geophysical data types are accommodated, including both wireline logs and laboratory analyses of downhole samples. Many processing tasks are handled by means of a single, flexible, general-purpose data-manipulation program. Separate programs are available for processing data from density, gravity, velocity, and epithermal neutron logs

  19. The lithospheric structure beneath Ireland and surrounding areas from integrated geophysical-petrological modelling of magnetic and other geophysical data

    Science.gov (United States)

    Baykiev, E.; Guerri, M.; Fullea, J.

    2017-12-01

    The availability of unprecedented resolution aeromagnetic data in Ireland (Tellus project, http://www.tellus.ie/) in conjunction with new satellite magnetic data (e.g., ESÁs Swarm mission) has opened the possibility of detailed modelling of the Irish subsurface magnetic structure. A detailed knowledge of the magnetic characteristics (susceptibility, magnetite content) of the crust is relevant for a number of purposes, including geological mapping and mineral and geothermal energy prospection. In this work we model the magnetic structure of Ireland and surrounding areas using primarily aeromagnetic and satellite observations but also other geophysical data sets. To this aim we use a geophysical-petrological modelling tool (LitMod) in which key properties of rocks (i.e., density, electrical conductivity and seismic velocities) that can be inferred from geophysical data (gravity, seismic, EM) are self consistently determined based on the thermochemical conditions (using the software Perple_X). In contrast to the mantle, where thermodynamic equilibrium is prevalent, in the crust metastable conditions are dominant, i.e. rock properties may not be representative of the current, in situ, temperature and pressure conditions. Instead, the rock properties inferred from geophysical data may be reflecting the mineralogy stable at rock formation conditions. In addition, temperature plays a major role in the distribution of the long wavelength crustal magnetic anomalies. Magnetite retains its magnetic properties below its Curie temperature (585 ºC) and the depth of Curie's isotherm provides an estimate of the thickness of the magnetic crust. Hence, a precise knowledge of the crustal geotherm is required to consistently model crustal magnetic anomalies. In this work LitMod has been modified to account for metastable crustal lithology, to predict susceptibility in the areas below Curie's temperature, and to compute magnetic anomalies based on a magnetic tesseroid approach. The

  20. Geophysics: Building E5481 decommissioning, Aberdeen Proving Ground

    International Nuclear Information System (INIS)

    Thompson, M.D.; McGinnis, M.G.; McGinnis, L.D.; Miller, S.F.

    1992-11-01

    Building E5481 is one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The building is located on the northern margin of a landfill that was sited in a wetland. The large number of magnetic sources surrounding the building are believed to be contained in construction fill that had been used to raise the grade. The smaller anomalies, for the most part, are not imaged with ground radar or by electrical profiling. A conductive zone trending northwest to southeast across the site is spatially related to an old roadbed. Higher resistivity areas in the northeast and east are probably representive of background values. Three high-amplitude, positive, rectangular magnetic anomalies have unknown sources. The features do not have equivalent electrical signatures, nor are they seen with radar imaging

  1. Alligator Rivers Analogue project. Geophysics, petrophysics and structure

    International Nuclear Information System (INIS)

    Emerson, D.W.; Mills, K.J.; Hallett, M.S.; Cao, L.Q.; Miyakawa, K.

    1992-01-01

    The geophysical and geological field work at Koongarra (including borehole core logging) showed that the site itself is a folded, faulted, variably fractured Precambrian psammitic and pelitic schist sequence with a quasi-horizontal weathered zone superimposed on the steeply dipping rock fabric. The site is flanked by a high resistivity younger sandstone unit to the northwest and by a magnetic amphibolite/ferricrete sequence to the far southeast. The data interpretations elicited the essential structural and broad lithological elements. Gravity, magnetic and electrical laboratory and field studies confirmed a broad folded fractured sequence of dipping layered host rocks weathered in their upper parts and trending in a southwest-northeast direction. Qualitatively interpreted anomalies indicated the trend of the main groundwater movement to the south where dolomites are thought to act as a sink. These drainage features have SP, resistivity and radiometric expression. The roles of the Kombolgie Sandstone as a source of water and the Koongarra Fault as a barrier or otherwise were not established owing to the lack of sufficient samples for testing and also on account of the difficulty of geophysical access over the site's rugged escarpment. 40 refs., 13 tabs., 69 figs

  2. How Collecting and Freely Sharing Geophysical Data Broadly Benefits Society

    Science.gov (United States)

    Frassetto, A.; Woodward, R.; Detrick, R. S.

    2017-12-01

    Valuable but often unintended observations of environmental and human-related processes have resulted from open sharing of multidisciplinary geophysical observations collected over the past 33 years. These data, intended to fuel fundamental academic research, are part of the Incorporated Research Institutions for Seismology (IRIS), which is sponsored by the National Science Foundation and has provided a community science facility supporting earthquake science and related disciplines since 1984. These community facilities have included arrays of geophysical instruments operated for EarthScope, an NSF-sponsored science initiative designed to understand the architecture and evolution of the North American continent, as well as the Global Seismographic Network, Greenland Ice Sheet Monitoring Network, a repository of data collected around the world, and other community assets. All data resulting from this facility have been made openly available to support researchers across any field of study and this has expanded the impact of these data beyond disciplinary boundaries. This presentation highlights vivid examples of how basic research activities using open data, collected as part of a community facility, can inform our understanding of manmade earthquakes, geomagnetic hazards, climate change, and illicit testing of nuclear weapons.

  3. Geophysics: Building E5375 decommissioning, Aberdeen Proving Ground

    International Nuclear Information System (INIS)

    McGinnis, M.G.; McGinnis, L.D.; Miller, S.F.; Thompson, M.D.

    1992-08-01

    Building E5375 was one of ten potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. Several anomalies wear, noted: (1) An underground storage tank located 25 ft east of Building E5375 was identified with magnetic, resistivity, and GPR profiling. (2) A three-point resistivity anomaly, 12 ft east of the northeast comer of Building E5374 (which borders Building E5375) and 5 ft south of the area surveyed with the magnetometer, may be caused by another underground storage tank. (3) A 2,500-gamma magnetic anomaly near the northeast corner of the site has no equivalent resistivity anomaly, although disruption in GPR reflectors was observed. (4) A one-point magnetic anomaly was located at the northeast comer, but its source cannot be resolved. A chaotic reflective zone to the east represents the radar signature of Building E5375 construction fill

  4. Geophysics: Building E5476 decommissiong, Aberdeen Proving Ground

    International Nuclear Information System (INIS)

    Miller, S.F.; Thompson, M.D.; McGinnis, M.G.; McGinnis, L.D.

    1992-11-01

    Building E5476 was one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The large number of magnetic sources surrounding the building are believed to be contained in construction fill. The smaller anomalies, for the most part, were not imaged with ground radar or by electrical profiling. Large magnetic anomalies near the southwest comer of the building are due to aboveground standpipes and steel-reinforced concrete. Two high-resistivity areas, one projecting northeast from the building and another south of the original structure, may indicate the presence of organic pore fluids in the subsurface. A conductive lineament protruding from the south wall that is enclosed by the southem, high-resistivity feature is not associated with an equivalent magnetic anomaly. Magnetic and electrical anomalies south of the old landfill boundary are probably not associated with the building. The boundary is marked by a band of magnetic anomalies and a conductive zone trending northwest to southeast. The cause of high resistivities in a semicircular area in the southwest comer, within the landfill area, is unexplained

  5. Geochemical factors affecting radionuclide transport through near and far fields at a Low-Level Waste Disposal Site

    International Nuclear Information System (INIS)

    Kaplan, D.I.; Seme, R.J.; Piepkho, M.G.

    1995-03-01

    The concentration of low-level waste (LLW) contaminants in groundwater is determined by the amount of contaminant present in the solid waste, rate of release from the waste and surrounding barriers, and a number of geochemical processes including adsorption, desorption, diffusion, precipitation, and dissolution. To accurately predict radionuclide transport through the subsurface, it is essential that the important geochemical processes affecting radionuclide transport be identified and, perhaps more importantly, accurately quantified and described in a mathematically defensible manner

  6. Geochemical prospecting in Morrinhos area - Ceara

    International Nuclear Information System (INIS)

    Andrade, V.A. de; Campos, M. de; Braga, A. de P.G.

    1982-01-01

    Morrinhos ring-shaped structure has been considered by several authors as reflecting a non-rising pluton, related to the regional uranium mineralization. NUCLEBRAS carried out a geochemical prospecting in the area, (through soil and stream samples), to better understand the relationship between the structure and the ore bodies. The 229 samples were all analysed for 33 trace-elements, using optical spectrography and X-ray fluorescence methods. (Author) [pt

  7. Summary report on geochemical barrier special study

    International Nuclear Information System (INIS)

    1988-12-01

    Long-term management of uranium mill tailings must provide assurance that soluble contaminants will not migrate beyond the Point of Compliance. Conventional management alternatives provide containment through the use of physical barriers which are designed to prevent migration of water through the tailings pile. An alternative is to geochemically modify the tailings to immobilize the contaminants. This investigation examined three potential geochemical modifiers to determine their ability to immobilize inorganic groundwater contaminants found in uranium mill tailings. These modifiers were hydrated lime (Ca(OH) 2 ), limestone (CaCO 3 ), and a sphaegnum peat moss. This investigation focused on both the geochemical interactions between the tailings and the modifiers, and the effects the modifiers had on the physical strength of the tailings. The geochemical investigations began with characterization of the tailings by X-ray diffraction and scanning electron microscopy. This was followed by batch leaching experiments in which various concentrations of each modifier were added to tailings in shaker flasks and allowed to come to equilibrium. Finally, column experiments were conducted to simulate flow through a tailings pile. The results show that all of the modifiers were at least moderately effective at immobilizing most of the groundwater contaminants of concern at uranium mill tailings sites. Hydrated lime was able to achieve 90 percent concentration reduction of arsenic, cadmium, selenium, uranium, and sulfate when added at a two percent concentration. Limestone was somewhat less effective and peat removed greater than 90 percent of arsenic, lead, uranium, and sulfate at a one percent concentration. The column tests showed that kinetic and/or mass transfer limitations are important and that sufficient time must be allowed for the immobilization reactions to occur

  8. Synthesizing Earth's geochemical data for hydrogeochemical analysis

    Science.gov (United States)

    Brantley, S. L.; Kubicki, J.; Miller, D.; Richter, D.; Giles, L.; Mitra, P.

    2007-12-01

    For over 200 years, geochemical, microbiological, and chemical data have been collected to describe the evolution of the surface earth. Many of these measurements are data showing variations in time or in space. To forward predict hydrologic response to changing tectonic, climatic, or anthropogenic forcings requires synthesis of these data and utilization in hydrogeochemical models. Increasingly, scientists are attempting to synthesize such data in order to make predictions for new regions or for future time periods. However, to make such complex geochemical data accessible requires development of sophisticated cyberinfrastructures that both invite uploading as well as usage of data. Two such cyberinfrastructure (CI) initiatives are currently developing, one to invite and promote the use of environmental kinetics data (laboratory time course data) through ChemxSeer, and the other to invite and promote the use of spatially indexed geochemical data for the Earth's Critical Zone through CZEN.org. The vision of these CI initiatives is to provide cyber-enhanced portals that encourage domain scientists to upload their data before publication (in private cyberspace), and to make these data eventually publicly accessible (after an embargo period). If the CI can be made to provide services to the domain specialist - e.g. to provide data analysis services or data comparison services - we envision that scientists will upload data. In addition, the CI can promote the use and comparison of datasets across disciplines. For example, the CI can facilitate the use of spatially indexed geochemical data by scientists more accustomed to dealing with time-course data for hydrologic flow, and can provide user-friendly interfaces with CI established to facilitate the use of hydrologic data. Examples of the usage of synthesized data to predict soil development over the last 13ky and its effects on active hydrological flow boundaries in surficial systems will be discussed for i) a N

  9. Geochemical and geo-electrical study of mud pools at the Mutnovsky volcano (South Kamchatka, Russia): Behavior of elements, structures of feeding channels and a model of origin

    International Nuclear Information System (INIS)

    Bessonova, E.P.; Bortnikova, S.B.; Gora, M.P.; Manstein, Yu.A.; Shevko, A.Ya.; Panin, G.L.; Manstein, A.K.

    2012-01-01

    This study presents data on the geochemical composition of boiling mud pools at the Mutnovsky volcano. The physicochemical characteristics of the pools and the concentrations of major, minor and trace elements in pool solutions vary widely. A comparison of the geochemical compositions of host rocks and solutions indicates that leaching from rocks is not the only source of chemicals in thermal solutions. Geophysical studies reveal the inner structure of thermal fields, which reflect the shapes of the underground reservoirs and feed channels. Using geophysical methods (electrical resistivity tomography and frequency domain investigations), it was shown that the vertical structure and complex geochemical zonation of the feed channels leads to a high contrast in the compositions of the mud solutions. These findings answer questions about the origin and composition of surface manifestations. To elucidate the mechanisms of solution formation, an attempt was made to describe the magmatic fluid evolution and the resulting mixing of waters by physical and mathematical models. The model illustrates fluid migration from a magma chamber to the surface. It is shown that the formation of brines corresponding to the mud pool composition is possible during secondary boiling.

  10. Drowning in Geochemical Data: The Good, the bad, and the Ugly

    Science.gov (United States)

    Hofmann, A. W.; Goldstein, S. L.

    2008-12-01

    , reservoir probably hidden near the base of the mantle. Among the most important changes triggered by the new databases are the following: (1) Driven by the database community, the standards required for reporting geochemical data in publications are changing in fundamental ways. Whereas it was common practice, especially in high-profile journals, to treat the data supporting the claims made in the published articles as relatively unimportant technical details, journal editors now require much more careful geochemical data reporting that includes complete data in numerical rather than graphical representation, information on sample locations, analytical methods, and uncertainty estimates. (2) Given the ever-increasing production rate of geochemical data, comprehensive use of geochemical data without relational databases is, or will soon be, impossible.

  11. Geochemical evolution of magmatism in Archean granite-greenstone terrains

    Science.gov (United States)

    Samsonov, A. V.; Larionova, Yu. O.

    2006-05-01

    Evolution of Archean magmatism is one of the key problems concerning the early formation stages of the Earth crust and biosphere, because that evolution exactly controlled variable concentrations of chemical elements in the World Ocean, which are important for metabolism. Geochemical evolution of magmatism between 3.5 and 2.7 Ga is considered based on database characterizing volcanic and intrusive rock complexes of granite-greenstone terrains (GGT) studied most comprehensively in the Karelian (2.9-2.7 Ga) and Kaapvaal (3.5-2.9 Ga) cratons and in the Pilbara block (3.5-2.9 Ga). Trends of magmatic geochemical evolution in the mentioned GGTs were similar in general. At the early stage of their development, tholeiitic magmas were considerably enriched in chalcophile and siderophile elements Fe2O3, MgO, Cr, Ni, Co, V, Cu, and Zn. At the next stage, calc-alkaline volcanics of greenstone belts and syntectonic TTG granitoids were enriched in lithophile elements Rb, Cs, Ba, Th, U, Pb, Nb, La, Sr, Be and others. Elevated concentrations of both the “crustal” and “mantle-derived” elements represented a distinctive feature of predominantly intrusive rocks of granitoid composition, which were characteristic of the terminal stage of continental crust formation in the GGTs, because older silicic rocks and lithospheric mantle were jointly involved into processes of magma generation. On the other hand, the GGTs different in age reveal specific trends in geochemical evolution of rock associations close in composition and geological position. First, the geochemical cycle of GGT evolution was of a longer duration in the Paleoarchean than in the Meso-and Neoarchean. Second, the Paleoarche an tholeiitic associations had higher concentrations of LREE and HFSE (Zr, Ti, Th, Nb, Ta, Hf) than their Meso-and Neoarchean counterparts. Third, the Y and Yb concentrations in Paleoarchean calc-alkaline rock associations are systematically higher than in Neoarchean rocks of the same type

  12. Experimental insights into geochemical changes in hydraulically fractured Marcellus Shale

    International Nuclear Information System (INIS)

    Marcon, Virginia; Joseph, Craig; Carter, Kimberly E.; Hedges, Sheila W.; Lopano, Christina L.; Guthrie, George D.; Hakala, J. Alexandra

    2017-01-01

    dissolution and secondary precipitation is observed in the presence of frac chemicals. • Organic acid, benzene and toluene concentrations increased in the experiment with frac chemicals. • SI for anhydrite depended on the redox conditions applied during geochemical modeling. • Calculations including organic acids decreased SI for barite and increased SI for smectite and carbonates.

  13. Preliminary study of volcano monitoring using geochemical composition of lichen

    Science.gov (United States)

    KUAN, S.

    2012-12-01

    Taipei City, the capital of Taiwan, is bounded with Tatun Volcano Group (TVG), which is not active since 200 ka. However, some evidences indicate that the latest explosion of volcanic ash was dated to 5-6 ka as well as TVG is so close to metropolis. The monitoring on TVG is crucial for crisis management. For monitoring TVG, changes of geochemical signal in some volcanic gases and hot springs are currently assessed by monthly sampling. The geochemistry of volcanic gas and hot spring represents a short-term condition on sampling time and is highly controlled by temperature and precipitation on the surface. A long-term average geochemistry will be very helpful to be compared with the results of volcanic gas and hot spring. A bioindicator not only has the ability to store geochemical compositions in their tissues but also has a wide geographical distribution. It is very suitable in this kind of study and lichen is one of the best bioindicators mainly because lichens grow slowly and have a large-scale dependence upon the environment for their nutrition, In TVG, the high SO2 content in the atmosphere results in the absence of fruticose lichen. On the contrary, crustos lichen is the most common species in the study area. For the preliminary analysis, one fruticose, four foliose and four crustos lichens were collected around the major emission centers of volcanic gas. According to the results of ICP-MS analysis, the abundances of heavy metals are generally in the order of Zn, Fe, Mn, Cu, Cr, Pb, Cd, Ni, V, Co and U. Factor analysis (FA) demonstrates that most of the metals show very high loadings in the first factor. This means that the fractionation of metals among different lichen species is minor and the geochemical compositions of lichen are possibly controlled by the same source (atmosphere). The second factor of FA includes Mn, Sr and Ba, which share the same oxidation state of +2 in acidic environment. This factor can describe the variation of Mn, Sr and Ba in the

  14. Hydrologic Regulation of Global Geochemical Cycles

    Science.gov (United States)

    Maher, K.

    2015-12-01

    Earth's temperature is thought to be regulated by a negative feedback between atmospheric CO2 levels and chemical weathering of silicate rocks. However, direct evidence for the operation of this feedback over million-year timescales is difficult to obtain. For example, weathering fluxes over the last 20 million years of the Cenozoic Era, calculated using marine isotopic proxies (i.e. 87Sr/86Sr, δ7Li, and 187Os/188Os), appear inconsistent with past atmospheric CO2 levels and carbon mass balance. Similarly, observations from modern catchments suggest that chemical weathering fluxes are strongly correlated with erosion rates and only weakly correlated with temperature. As an alternative approach to evaluating the operation of a negative feedback, we use the major surface reservoirs of carbon to determine the imbalance in the geologic carbon cycle and the required silicate weathering flux over the Cenozoic. A miniscule (0.5-1%) increase in silicate weathering is necessary to explain the long-term decline in CO2 levels over the Cenozoic, providing evidence for a strong negative feedback between silicate weathering and climate. Rather than an appreciable increase in the silicate weathering flux, the long-term decrease in CO2levels may be due to an increase in the strength of the silicate weathering feedback. To explain the observed variations in the strength of the weathering feedback during the Cenozoic, we present a model for silicate weathering where hydrologic processes regulate climatic and tectonic forcings due to the presence of a thermodynamic limit to weathering fluxes. Climate regulation by silicate weathering is thus strongest when global topography is elevated, similar to today, and lowest when global topography is more subdued, allowing planetary temperatures to vary depending on the global distribution of topography and mountain belts. These results also motivate several key outstanding challenges in earth surface processes, including the need to

  15. Sharp fronts within geochemical transport problems

    International Nuclear Information System (INIS)

    Grindrod, P.

    1995-01-01

    The authors consider some reactive geochemical transport problems in groundwater systems. When incoming fluid is in disequilibrium with the mineralogy sharp transition fronts may develop. They show that this is a generic property for a class of systems where the timescales associated with reaction and diffusion phenomena are much shorter than those associated with advective transport. Such multiple timescale problems are relevant to a variety of processes in natural systems: mathematically methods of singular perturbation theory reduce the dimension of the problems to be solved locally. Furthermore, they consider how spatial heterogeneous mineralogy can impact upon the propagation of sharp geochemical fronts. The authors developed an asymptotic approach in which they solve equations for the evolving geometry of the front and indicate how the non-smooth perturbations due to natural heterogeneity of the mineralogy on underlying ground water flow field are balanced against the smoothing effect of diffusion/dispersive processes. Fronts are curvature damped, and the results here indicate the generic nature of separate front propagation within both model (idealized) and natural (heterogeneous) geochemical systems

  16. Basic concepts and formulations for isotope geochemical modelling of groundwater systems

    International Nuclear Information System (INIS)

    Kalin, R.M.

    1996-01-01

    This chapter describes the basic chemical principles and methodologies for geochemical models and their use in the field of isotope hydrology. Examples of calculation procedures are given on actual field data. Summary information on available PC software for geochemical modeling is included. The specific software, NETPATH, which can be used for chemical speciation, mass balance and isotope balance along a flow path in groundwater systems, is discussed at some length with an illustrative example of its application to field data. (author). Refs, 14 figs, 15 tabs

  17. New determination of period and quality factor of Chandler wobble, considering geophysical excitations

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jan; Ron, Cyril; Chapanov, Y.

    2017-01-01

    Roč. 59, č. 5 (2017), s. 1395-1407 ISSN 0273-1177 R&D Projects: GA ČR GA13-15943S Institutional support: RVO:67985815 Keywords : polar motion * chandler wobble * geophysical excitations Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 1.401, year: 2016

  18. Advances in Airborne and Ground Geophysical Methods for Uranium Exploration

    International Nuclear Information System (INIS)

    2013-01-01

    One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world'. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. According to current estimates, after 2050 available resources and cumulative uranium demand are expected to be balanced. Recent annual uranium production constitutes 65-75% of annual nuclear energy uranium requirements worldwide. With typical timeframes of between 15 and 40 years from the commencement of uranium exploration activities until uranium production, together with increasingly favourable uranium prices, many countries have seen a rise in uranium exploration activities since 2005. This experience and assessment of global energy needs support continued uranium exploration

  19. Geophysical Hunt for Chromite in Ophiolite

    Directory of Open Access Journals (Sweden)

    Mubarik Ali

    2013-12-01

    Full Text Available Ophiolite of Oman are famous world over, and are favorite for exploring chromite, which is a source of chromium that is used widely in steel, nichrome, and plating and painting industries. The best known chromite deposits are found in the Bushveld complex of South africa, however countries like Pakistan and Oman are also contributing but less than 2% of the world production. Chromite is found in the mantle rocks such as peridotite and its altered products. Large economic deposits are generally found in stratiform structure and the smaller ones in pod-like or tabular lenses. In Oman the chromite deposits occur in Oman ophiolite (Semile, mainly in the mantle sequence comprising harzburgite and dunite. The mining efforts for chromite in Oman are in progress but not on scientific grounds. On a site called Izki (670 m asl the chromite was expected on the top of a hill in a small area (150x50 m of ophiolite, and mining through pitting procedure was tried over there but remained unsuccessful. Geophysical methods were applied in the same area to search out the possibility of the existence of the ore. Since chromite is denser, more conductive and magnetically less susceptible deposit as compared to the host rocks harzburgite and serpentinite, it is expected that the existence of a shallow sizable ore body would generate favorable gravity, magnetic, and resistivity signals. The integrated geophysical study (gravity, magnetic and resistivity reveals the probability of chromite within 30 m depth. For confirmation the drilling was recommended on a point upto a depth of 35 meters. The drilling could not be continued beyond 12 meters depth due to reasons known to the lease owner. The drilling showed harzburgite up to 8 meters depth, then a chromite layer of 0.7 meter thickness, after that harzburgite started for the next 3 meters depth. This state of affairs confirms not only the presence of chromite but also the revealing power of geophysics.

  20. Atmospheric and Geophysical Sciences Division: Program report, FY 1987

    International Nuclear Information System (INIS)

    1988-05-01

    In 1988 the Atmospheric and Geophysical Sciences Division began its 15th year as a division. As the Division has grown over the years, its modeling capabilities have expanded to include a broad range of time and space scales ranging from hours to years, and from kilometers to global, respectively. For this report, we have chosen to show a subset of results from several projects to illustrate the breadth, depth, and diversity of the modeling activities that are a major part of the Division's research, development, and application efforts. In addition, the recent reorganization of the Division, including the merger of another group with the Division, is described, and the budget, personnel, models, and publications are reviewed. 95 refs., 26 figs., 2 tabs

  1. Atmospheric and Geophysical Sciences Division: Program report, FY 1987

    Energy Technology Data Exchange (ETDEWEB)

    1988-05-01

    In 1988 the Atmospheric and Geophysical Sciences Division began its 15th year as a division. As the Division has grown over the years, its modeling capabilities have expanded to include a broad range of time and space scales ranging from hours to years, and from kilometers to global, respectively. For this report, we have chosen to show a subset of results from several projects to illustrate the breadth, depth, and diversity of the modeling activities that are a major part of the Division's research, development, and application efforts. In addition, the recent reorganization of the Division, including the merger of another group with the Division, is described, and the budget, personnel, models, and publications are reviewed. 95 refs., 26 figs., 2 tabs.

  2. Large natural geophysical events: planetary planning

    International Nuclear Information System (INIS)

    Knox, J.B.; Smith, J.V.

    1984-09-01

    Geological and geophysical data suggest that during the evolution of the earth and its species, that there have been many mass extinctions due to large impacts from comets and large asteroids, and major volcanic events. Today, technology has developed to the stage where we can begin to consider protective measures for the planet. Evidence of the ecological disruption and frequency of these major events is presented. Surveillance and warning systems are most critical to develop wherein sufficient lead times for warnings exist so that appropriate interventions could be designed. The long term research undergirding these warning systems, implementation, and proof testing is rich in opportunities for collaboration for peace

  3. Predictability of extreme values in geophysical models

    Directory of Open Access Journals (Sweden)

    A. E. Sterk

    2012-09-01

    Full Text Available Extreme value theory in deterministic systems is concerned with unlikely large (or small values of an observable evaluated along evolutions of the system. In this paper we study the finite-time predictability of extreme values, such as convection, energy, and wind speeds, in three geophysical models. We study whether finite-time Lyapunov exponents are larger or smaller for initial conditions leading to extremes. General statements on whether extreme values are better or less predictable are not possible: the predictability of extreme values depends on the observable, the attractor of the system, and the prediction lead time.

  4. Surface exploration geophysics applied to the moon

    International Nuclear Information System (INIS)

    Ander, M.E.

    1984-01-01

    With the advent of a permanent lunar base, the desire to explore the lunar near-surface for both scientific and economic purposes will arise. Applications of exploration geophysical methods to the earth's subsurface are highly developed. This paper briefly addresses some aspects of applying this technology to near surface lunar exploration. It is noted that both the manner of application of some techniques, as well as their traditional hierarchy as assigned on earth, should be altered for lunar exploration. In particular, electromagnetic techniques may replace seismic techniques as the primary tool for evaluating near-surface structure

  5. ''Radon-emanometry'' applied to internal geophysics

    International Nuclear Information System (INIS)

    Seidel, J.L.

    1982-02-01

    An experimental set-up for in ground radon 222 measurements has been realised with solid state track detectors (cellulose nitrates CN85 and LR115). A preliminary study of radon activity variations has been conducted over various sites expecting using radon as one of forerunner geophysical parameters of volcanic eruptions and earthquakes predictions. The first data obtained in the field are presented: Etna (Sicily), Krafla (Iceland), Poas and Arenal (Costa Rica), Colima and Paricutin (Mexico) for active volcanoes, Ech Cheliff (Algeria) and Alsace (France) for sismotectonic areas [fr

  6. Parallel block inversion of geophysical data

    Science.gov (United States)

    Pereyra, Victor L.

    1993-12-01

    We present an automatic blocking algorithm for some medium size nonlinear least squares problems that arise in the inversion of travel time data in geophysics. This blocking leads to a nonlinear Gauss-Seidel type iteration which can be distributed to a network of computers. The low dimensional blocks are also amenable to global optimization methods which leads to further parallelization. All this is necessary because the original problem is generally non- convex, ill-conditioned, with a goal functional that is very expensive to evaluate.

  7. Large natural geophysical events: planetary planning

    Energy Technology Data Exchange (ETDEWEB)

    Knox, J.B.; Smith, J.V.

    1984-09-01

    Geological and geophysical data suggest that during the evolution of the earth and its species, that there have been many mass extinctions due to large impacts from comets and large asteroids, and major volcanic events. Today, technology has developed to the stage where we can begin to consider protective measures for the planet. Evidence of the ecological disruption and frequency of these major events is presented. Surveillance and warning systems are most critical to develop wherein sufficient lead times for warnings exist so that appropriate interventions could be designed. The long term research undergirding these warning systems, implementation, and proof testing is rich in opportunities for collaboration for peace.

  8. Geochemical factors in borehole-shaft plug longevity

    International Nuclear Information System (INIS)

    Roy, D.M.

    1981-01-01

    Geochemical investigations that address factors controlling the longevity of repository sealing materials in a geochemical environment are discussed. Studies are being made of cement-based materials as major candidates for seals for borehole plugging, and shaft and tunnel sealing in certain potential repository environments. Factors controlling the extent of attainment of equilibrium of the plug components with time and the rate of approach to a state of stable equilibrium of the plug component chemical subsystem within the total system are discussed. The effect of these factors on changes in physical, mechanical and thermal properties of a seal system, and the consequent effectiveness of the seal in preventing transport of radioactive waste species are the dominant features to be determined. Laboratory experiments on the effects of anticipated temperature, pressure, and environmental factors (including chemical composition and specific rock type) are described. Thermodynamic studies are used to determine the potentially stable reaction products under conditions similar to those anticipated for the repository boreholes, shafts, and tunnels during and after the operating stage. Multitemperature reaction series are studied, and reaction kinetics are investigated for the purpose of predicting the course of likely reactions. Detailed studies of permeability, diffusion, and interfacial properties and chemical and microphase characterization of the products of experiments are carried out. Characterization studies of old and ancient cements, mortars, and concretes and prototype man-made seal materials are performed to further assess the factors associated with longevity

  9. Artificial intelligence and dynamic systems for geophysical applications

    CERN Document Server

    Gvishiani, Alexei

    2002-01-01

    The book presents new clustering schemes, dynamical systems and pattern recognition algorithms in geophysical, geodynamical and natural hazard applications. The original mathematical technique is based on both classical and fuzzy sets models. Geophysical and natural hazard applications are mostly original. However, the artificial intelligence technique described in the book can be applied far beyond the limits of Earth science applications. The book is intended for research scientists, tutors, graduate students, scientists in geophysics and engineers

  10. pyGIMLi: An open-source library for modelling and inversion in geophysics

    Science.gov (United States)

    Rücker, Carsten; Günther, Thomas; Wagner, Florian M.

    2017-12-01

    Many tasks in applied geosciences cannot be solved by single measurements, but require the integration of geophysical, geotechnical and hydrological methods. Numerical simulation techniques are essential both for planning and interpretation, as well as for the process understanding of modern geophysical methods. These trends encourage open, simple, and modern software architectures aiming at a uniform interface for interdisciplinary and flexible modelling and inversion approaches. We present pyGIMLi (Python Library for Inversion and Modelling in Geophysics), an open-source framework that provides tools for modelling and inversion of various geophysical but also hydrological methods. The modelling component supplies discretization management and the numerical basis for finite-element and finite-volume solvers in 1D, 2D and 3D on arbitrarily structured meshes. The generalized inversion framework solves the minimization problem with a Gauss-Newton algorithm for any physical forward operator and provides opportunities for uncertainty and resolution analyses. More general requirements, such as flexible regularization strategies, time-lapse processing and different sorts of coupling individual methods are provided independently of the actual methods used. The usage of pyGIMLi is first demonstrated by solving the steady-state heat equation, followed by a demonstration of more complex capabilities for the combination of different geophysical data sets. A fully coupled hydrogeophysical inversion of electrical resistivity tomography (ERT) data of a simulated tracer experiment is presented that allows to directly reconstruct the underlying hydraulic conductivity distribution of the aquifer. Another example demonstrates the improvement of jointly inverting ERT and ultrasonic data with respect to saturation by a new approach that incorporates petrophysical relations in the inversion. Potential applications of the presented framework are manifold and include time

  11. Increasing diversity in the geosciences through the AfricaArray geophysics field course

    Science.gov (United States)

    Vallejo, G.; Emry, E.; Galindo, B. L.; Carranza, V.; Gomez, C. D.; Ortiz, K.; Castro, J. G.; Guandique, J.; Falzone, C.; Webb, S. J.; Manzi, M.; Mngadi, S. B.; Stephens, K.; Chinamora, B.; Whitehead, R.; de Villiers, D. P.; Tshitlho, K.; Delhaye, R. P.; Smith, J. A.; Nyblade, A.

    2014-12-01

    For the past nine years, the AfricaArray diversity program, sponsored by industry, the National Science Foundation, and several partnering universities have supported outstanding U.S. STEM underrepresented minority undergraduates to gain field experience in near-surface geophysical techniques during an 8-week summer program at Penn State University and the University of Witwatersrand (Wits). The AfricaArray geophysics field school, which is run by Wits, has been teaching field-based geophysics to African students for over a decade. In the first 2-3 weeks of the program, the U.S. students are given basic instruction in near-surface geophysics, South African geology, and South African history and culture. The students then join the Wits AfricaArray geophysics field school - working alongside Wits students and students from several other African universities to map the shallow subsurface in prospective areas of South Africa for platinum mining. In addition to the primary goals of collecting and interpreting gravity, magnetic, resistivity, seismic refraction, seismic reflection, and EM data, students spend time mapping geologic units and gathering information on the physical properties of the rocks in the region (i.e. seismic velocity, density, and magnetic susceptibility). Subsurface targets include mafic dikes, faults, the water table, and overburden thickness. Upon returning to the U.S., students spend 2-3 weeks finalizing their project reports and presentations. The program has been effective at not only providing students with fundamental skills in applied geophysics, but also in fostering multicultural relationships, preparing students for graduate work in the geosciences, and attracting STEM students into the geosciences. Student presenters will discuss their experiences gained through the field school and give their impressions about how the program works towards the goal of increasing diversity in the geosciences in the U.S.

  12. Geophysical and Geochemical Constraints on the Age and Paleoclimate Implications of Holocene Lacustrine Cores from the Central Chilean Andes

    Science.gov (United States)

    Tiner, R.; Negrini, R. M.; Antinao, J. L.; Maldonado, A.

    2016-12-01

    A Holocene paleoclimate record has been constructed using two lacustrine cores from the high-elevation Chilean Andes at 30° S latitude. Coarser grain sizes, bimodal grain-size distributions, greater carbon and nitrogen weight percentages, and C/N ratios were found to co-vary suggesting increased storm activity and wet climate. The Holocene began with a wet period from 10.9-9.5 cal ka BP, then transitioned to dry conditions from 9.5-5.5 cal ka BP interrupted by wet conditions from 8.3-7.7 cal ka BP. Wet conditions prevailed from 5.5 cal ka BP-present, interrupted by two short arid periods from 4.9-4.4 cal ka BP and 2.6-2.2 cal ka BP. This paleoclimate record is consistent with others from the region and with preliminary pollen data from the same cores. Accordingly, the wet periods with greater storm activity are likely caused by the prevalent influence of the westerlies, while dry conditions are the result of the dominant influence of the Southeast Pacific anticyclone. Furthermore, the increased storminess from 8.3-7.7 cal ka BP may have been sourced from latitudinal shifts in the Intertropical Convergence Zone, possibly representing a southern hemisphere effect of the widespread 8.2 ka event first detected in Greenland ice cores.

  13. SIGKit: Software for Introductory Geophysics Toolkit

    Science.gov (United States)

    Kruse, S.; Bank, C. G.; Esmaeili, S.; Jazayeri, S.; Liu, S.; Stoikopoulos, N.

    2017-12-01

    The Software for Introductory Geophysics Toolkit (SIGKit) affords students the opportunity to create model data and perform simple processing of field data for various geophysical methods. SIGkit provides a graphical user interface built with the MATLAB programming language, but can run even without a MATLAB installation. At this time SIGkit allows students to pick first arrivals and match a two-layer model to seismic refraction data; grid total-field magnetic data, extract a profile, and compare this to a synthetic profile; and perform simple processing steps (subtraction of a mean trace, hyperbola fit) to ground-penetrating radar data. We also have preliminary tools for gravity, resistivity, and EM data representation and analysis. SIGkit is being built by students for students, and the intent of the toolkit is to provide an intuitive interface for simple data analysis and understanding of the methods, and act as an entrance to more sophisticated software. The toolkit has been used in introductory courses as well as field courses. First reactions from students are positive. Think-aloud observations of students using the toolkit have helped identify problems and helped shape it. We are planning to compare the learning outcomes of students who have used the toolkit in a field course to students in a previous course to test its effectiveness.

  14. Geophysical forecast: industry expects busy winter season

    Energy Technology Data Exchange (ETDEWEB)

    Ludwick, J.

    1997-11-01

    Survey results by the Canadian Association of Geophysical Contractors were discussed. According to the survey, all of the sector`s 65 crews will be fully utilized this winter, although no activity records are expected. Charges are likely to be slightly higher than last year. At least some of the increase will go towards increased pay to attract more workers into the field in an effort to counter the labour shortage in the seismic industry. Contractors must compete with other sectors such as construction, which is booming as a result of Alberta`s burgeoning economy. The Slave Lake and Rocky Mountain House regions are expected to be the hottest in Alberta. Southeastern Saskatchewan also promises to be the site of increased activity due to the growing interest in the Red River oil play. Another reason for the increased activity may be the use of innovative technology such as that employed by Enertec Geophysical Service Limited. It will pilot-test its newly acquired PowerProbe technology, which is said to be able to immediately detect the presence of hydrocarbons.

  15. Using Geophysical Data to Improve Science Literacy

    Science.gov (United States)

    van der Vink, G. E.

    2002-12-01

    Although relatively few students will become professional geoscientists (i.e. producers of scientific information), essentially every student is a future consumer of scientific information. Government agencies, environmental organizations, businesses, and special interest groups use scientific arguments to set policy, create legislation, and develop international agreements. Often, decisions must be made even though the data are incomplete, ambiguous, or contradictory. In addition, such decisions frequently have severe social, economic, and political consequences. At Princeton University, we have developed courses designed to make students sophisticated consumers of scientific information. The courses are among the most popular and top rated courses in the University. Through a series of actual case studies that use geophysical data, students learn how to make decisions using scientific information in concert with engineering, economic, political, and social considerations. For each issue, they analyze the scientific arguments, evaluate the geophysical data upon which they are based, and determine the scientific credibility, political feasibility, and economic consequences of the various options. The class's actions are then compared against those of the actual decision-makers, and the accuracy of their predictions is evaluated against the outcome. Students gain first-hand experience with concepts such as valid inference, representative sampling, boundary values, and data discrimination.

  16. Spatial and temporal distribution of geophysical disasters

    Directory of Open Access Journals (Sweden)

    Cvetković Vladimir

    2013-01-01

    Full Text Available Natural disasters of all kinds (meteorological, hydrological, geophysical, climatological and biological are increasingly becoming part of everyday life of modern human. The consequences are often devastating, to the life, health and property of people, as well to the security of states and the entire international regions. In this regard, we noted the need for a comprehensive investigation of the phenomenology of natural disasters. In addition, it is particularly important to pay attention to the different factors that might correlate with each other to indicate more dubious and more original facts about their characteristics. However, as the issue of natural disasters is very wide, the subject of this paper will be forms, consequences, temporal and spatial distribution of geophysical natural disasters, while analysis of other disasters will be the subject of our future research. Using an international database on natural disasters of the centre for research on the epidemiology of disasters (CRED based in Brussels, with the support of the statistical analysis (SPSS, we tried to point out the number, trends, consequences, the spatial and temporal distribution of earthquakes, volcanic eruptions and dry mass movements in the world, from 1900 to 2013.

  17. Nuclear geophysics for studying oil fields

    International Nuclear Information System (INIS)

    Alekseev, F.A.; Golovatskaya, I.V.; Gulin, Yu.A.; Dvorkin, I.L.; Dyad'kin, I.G.; Srebrodol'skij, D.M.

    1978-01-01

    Considered are the theory of nuclear geophysics and analytical methods to be used in the study of neutron and gamma-quantum fields. The following questions of nuclear geology are discussed: the regularities of radioactive element distributions in oil/gas bearing sedimentary deposits of oils and underground waters; applications of natural gamma-radiation spectrometry in the study of sedimentary processes and etc. Also described are the nuclear geophysics stationary methods (gamma-logging, gamma-gamma-logging, neutron logging) to be followed when developing geological documentation for borehole profiles; the use and efficiency of stationary and impulse techniques in monitoring an oil minig in different geological/technical conditions; the technique to be used for an additional prospecting of layers (carbonate, primarily) in old cased-off holes; the methods to be used in performing a quality inspection of pipe casing cementation and making measurements of their inner diameter and wall thickness. The investigation technique data are provided to examine boreholes with the aid of radioactive isotopes

  18. Applications of geophysics to LLRW sites

    International Nuclear Information System (INIS)

    Olhoeft, G.R.

    1984-01-01

    There are many geophysical techniques which noninvasively acquire information about hazardous waste sites. Waste buried in metal drums can be located using magnetic and electromagnetic methods. Ground penetrating radar can provide detailed cross-sectional imagery of the ground to locate metallic and nonmetallic objects, and to delineate water tables and geologic structure. Complex resistivity can locate clay horizons or clay liners and detect organic reactions that may increase the permeability of the clay. Seismic refraction and reflection techniques can detail hydrology and stratigraphy. Microgravity techniques can find local density anomalies that may indicate voids or future subsidence problems. Radiometric techniques can directly detect near-surface radioisotope migration. Nothing works all the time, however. Magnetics cannot detect a badly corroded drum. Complex resistivity cannot detect clay-organic reactions if there are no clays. Ground penetrating radar cannot penetrate high conductivity or high clay content soils. Seismic cannot penetrate loose fill. Each technique has advantages and disadvantages inherent to the method and equipment as well as limitations imposed by the geohydrology at the site of application. Examples from both the Radioactive Waste and Hazardous Chemical Waste programs illustrate the advantages and disadvantages of geophysical methods

  19. Geophysical mapping of palsa peatland permafrost

    Science.gov (United States)

    Sjöberg, Y.; Marklund, P.; Pettersson, R.; Lyon, S. W.

    2015-03-01

    Permafrost peatlands are hydrological and biogeochemical hotspots in the discontinuous permafrost zone. Non-intrusive geophysical methods offer a possibility to map current permafrost spatial distributions in these environments. In this study, we estimate the depths to the permafrost table and base across a peatland in northern Sweden, using ground penetrating radar and electrical resistivity tomography. Seasonal thaw frost tables (at ~0.5 m depth), taliks (2.1-6.7 m deep), and the permafrost base (at ~16 m depth) could be detected. Higher occurrences of taliks were discovered at locations with a lower relative height of permafrost landforms, which is indicative of lower ground ice content at these locations. These results highlight the added value of combining geophysical techniques for assessing spatial distributions of permafrost within the rapidly changing sporadic permafrost zone. For example, based on a back-of-the-envelope calculation for the site considered here, we estimated that the permafrost could thaw completely within the next 3 centuries. Thus there is a clear need to benchmark current permafrost distributions and characteristics, particularly in under studied regions of the pan-Arctic.

  20. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    Science.gov (United States)

    Schertzer, D.; Lovejoy, S.

    1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3) was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986), NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991), five consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions. As with the other conferences and workshops mentioned above, the aim was to develop confrontation between theories and experiments on scaling/multifractal behaviour of geophysical fields. Subjects covered included climate, clouds, earthquakes, atmospheric and ocean dynamics, tectonics, precipitation, hydrology, the solar cycle and volcanoes. Areas of focus included new methods of data analysis (especially those used for the reliable estimation of multifractal and scaling exponents), as well as their application to rapidly growing data bases from in situ networks and remote sensing. The corresponding modelling, prediction and estimation techniques were also emphasized as were the current debates about stochastic and deterministic dynamics, fractal geometry and multifractals, self-organized criticality and multifractal fields, each of which was the subject of a specific general discussion. The conference started with a one day short course of multifractals featuring four lectures on a) Fundamentals of multifractals: dimension, codimensions, codimension formalism, b) Multifractal estimation techniques: (PDMS, DTM), c) Numerical simulations, Generalized Scale Invariance analysis, d) Advanced multifractals, singular statistics, phase transitions, self-organized criticality and Lie cascades (given by D. Schertzer and S. Lovejoy, detailed course notes were sent to participants shortly after the conference). This

  1. EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

    Directory of Open Access Journals (Sweden)

    D. Schertzer

    1994-01-01

    Full Text Available 1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3 was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986, NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991, five consecutive annual sessions at EGS general assemblies and two consecutive spring AGU meeting sessions. As with the other conferences and workshops mentioned above, the aim was to develop confrontation between theories and experiments on scaling/multifractal behaviour of geophysical fields. Subjects covered included climate, clouds, earthquakes, atmospheric and ocean dynamics, tectonics, precipitation, hydrology, the solar cycle and volcanoes. Areas of focus included new methods of data analysis (especially those used for the reliable estimation of multifractal and scaling exponents, as well as their application to rapidly growing data bases from in situ networks and remote sensing. The corresponding modelling, prediction and estimation techniques were also emphasized as were the current debates about stochastic and deterministic dynamics, fractal geometry and multifractals, self-organized criticality and multifractal fields, each of which was the subject of a specific general discussion. The conference started with a one day short course of multifractals featuring four lectures on a Fundamentals of multifractals: dimension, codimensions, codimension formalism, b Multifractal estimation techniques: (PDMS, DTM, c Numerical simulations, Generalized Scale Invariance analysis, d Advanced multifractals, singular statistics, phase transitions, self-organized criticality and Lie cascades (given by D. Schertzer and S. Lovejoy, detailed course notes were sent to participants shortly after the

  2. Proposed geologic model based on geophysical well logs

    Energy Technology Data Exchange (ETDEWEB)

    Diaz C, S.; Puente C, I.; de la Pena L, A.

    1981-01-01

    An investigation of the subsurface based on a qualitative interpretation of well logs was carried out at Cerro Prieto to obtain information on the distribution of the different lithofacies that make up a deltaic depositional system. The sedimentological interpretation derived from the resistivity and spontaneous potential are shown in several cross-sections of the field. In addition to the sedimentological interpretation, a map of the structural geology of the region based on well logs and available geophysical information was prepared, including the results of gravity and seismic refraction surveys. The depth to the zone of hydrothermal alteration described by Elders (1980) was found by means of temperature, electrical, and radioactive logs. Two maps showing the configuration of the top of this anomaly show a clear correlation with the gravity anomalies found in the area.

  3. Landscape-geochemical factors of deposit formation

    International Nuclear Information System (INIS)

    Batulin, S.G.

    1980-01-01

    Effect of landscape-geochemical factors on hydrogenic formation of uranium ores is considered. The primary attention is paid to finding reasons for hydrogeochemical background increase in the regions of arid climate. Problems of uranium distribution in alluvial landscapes, hydrogeochemical regime of ground waters, reflecting the effect of waters of the zone of aeration are revealed. Chemical composition of porous solutions in the zone of aeration, as well as historical geochemindstry of landscape a its role from the view point of uranium solution formation in the arid zone are considered [ru

  4. sedimentological and geochemical characteristics of outcrop ...

    African Journals Online (AJOL)

    USER

    0.17. 0.70. 1.13. 1.37. -. CIA (%). 73.00. 76.00. 74.00. 85.00. 99.00. 95.00. 98.00. 90.00. 96.00. 77.00. 99.00. 96.00. 94.00. -. CIW (%). 78.00. 87.00. 83.00. 97.00. 100.00. 99.00. 100. 99.00. 99.00. 86.00. 00. 99.00. 100.00. -. Nton and Adamolekun: Sedimentological and Geochemical Characteristics of Outcrop Sediments ...

  5. DNA-based methods of geochemical prospecting

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, Matthew [Mill Valley, CA

    2011-12-06

    The present invention relates to methods for performing surveys of the genetic diversity of a population. The invention also relates to methods for performing genetic analyses of a population. The invention further relates to methods for the creation of databases comprising the survey information and the databases created by these methods. The invention also relates to methods for analyzing the information to correlate the presence of nucleic acid markers with desired parameters in a sample. These methods have application in the fields of geochemical exploration, agriculture, bioremediation, environmental analysis, clinical microbiology, forensic science and medicine.

  6. Kriging - a challenge in geochemical mapping

    Science.gov (United States)

    Stojdl, Jiri; Matys Grygar, Tomas; Elznicova, Jitka; Popelka, Jan; Vachova, Tatina; Hosek, Michal

    2017-04-01

    Geochemists can easily provide datasets for contamination mapping thanks to recent advances in geographical information systems (GIS) and portable chemical-analytical instrumentation. Kriging is commonly used to visualise the results of such mapping. It is understandable, as kriging is a well-established method of spatial interpolation. It was created in 1950's for geochemical data processing to estimate the most likely distribution of gold based on samples from a few boreholes. However, kriging is based on the assumption of continuous spatial distribution of numeric data that is not realistic in environmental geochemistry. The use of kriging is correct when the data density is sufficient with respect to heterogeneity of the spatial distribution of the geochemical parameters. However, if anomalous geochemical values are focused in hotspots of which boundaries are insufficiently densely sampled, kriging could provide misleading maps with the real contours of hotspots blurred by data smoothing and levelling out individual (isolated) but relevant anomalous values. The data smoothing can thus it results in underestimation of geochemical extremes, which may in fact be of the greatest importance in mapping projects. In our study we characterised hotspots of contamination by uranium and zinc in the floodplain of the Ploučnice River. The first objective of our study was to compare three methods of sampling: random (based on stochastic generation of sampling points), systematic (square grid) and judgemental sampling (based on judgement stemming from principles of fluvial deposition) as the basis for pollution maps. The first detected problem in production of the maps was the reduction of the smoothing effect of kriging using appropriate function of empirical semivariogram and setting the variation of at microscales smaller than the sampling distances to minimum (the "nugget" parameter of semivariogram). Exact interpolators such as Inverse Distance Weighting (IDW) or Radial

  7. The geochemical landscape of northwestern Wisconsin and adjacent parts of northern Michigan and Minnesota (geochemical data files)

    Science.gov (United States)

    Cannon, William F.; Woodruff, Laurel G.

    2003-01-01

    This data set consists of nine files of geochemical information on various types of surficial deposits in northwestern Wisconsin and immediately adjacent parts of Michigan and Minnesota. The files are presented in two formats: as dbase files in dbaseIV form and Microsoft Excel form. The data present multi-element chemical analyses of soils, stream sediments, and lake sediments. Latitude and longitude values are provided in each file so that the dbf files can be readily imported to GIS applications. Metadata files are provided in outline form, question and answer form and text form. The metadata includes information on procedures for sample collection, sample preparation, and chemical analyses including sensitivity and precision.

  8. A stream sediment geochemical survey of the Ganga River headwaters in the Garhwal Himalaya

    Science.gov (United States)

    Mukherjee, P.K.; Purohit, K.K.; Saini, N.K.; Khanna, P.P.; Rathi, M.S.; Grosz, A.E.

    2007-01-01

    This study models geochemical and adjunct geologic data to define provinces that are favorable for radioactive-mineral exploration. A multi-element bed-sediment geochemical survey of streams was carried out in the headwaters region of the Ganga River in northern India. Overall median values for uranium and thorium (3.6 and 13.8 ppm; maxima of 4.8 and 19.0 ppm and minima of 3.1 and 12.3 ppm respectively) exceed average upper crustal abundances (2.8 and 10.7 ppm) for these radioactive elements. Anomalously high values reach up to 8.3 and 30.1 ppm in thrust zone rocks, and 11.4 and 22.5 ppm in porphyroids. At their maxima, these abundances are nearly four- and three-fold (respectively) enriched in comparison to average crustal abundances for these rock types. Deformed, metamorphosed and sheared rocks are characteristic of the main central thrust zone (MCTZ). These intensively mylonitized rocks override and juxtapose porphyritic (PH) and proterozoic metasedimentary rock sequences (PMS) to the south. Granitoid rocks, the major protoliths for mylonites, as well as metamorphosed rocks in the MCT zone are naturally enriched in radioelements; high values associated with sheared and mylonitized zones are coincident with reports of radioelement mineralization and with anomalous radon concentrations in soils. The radioelement abundance as well as REE abundance shows a northward enrichment trend consistent with increasing grade of metamorphism indicating deformation-induced remobilization of these elements. U and Th illustrate good correlation with REEs but not with Zr. This implies that zircon is not a principal carrier of U and Th within the granitoid-dominant thrust zone and that other radioelement-rich secondary minerals are present in considerable amounts. Thus, the relatively flat, less fractionated, HREE trend is also not entirely controlled by zircon. The spatial correlation of geologic boundary zones (faults, sheared zones) with geochemical and with geophysical (Rn

  9. Educational Geophysics at INGV, Rome (Italy)

    Science.gov (United States)

    Dida Working Group Ingv,.

    2002-12-01

    Italy is a country prone to Earth phenomena such as earthquakes, volcanic eruptions, floods and landslides that left a trace in the memory of people. About 60% of the Italian territory is classified in the current seismic hazard maps, and large cities as Neaples and Catania are located close to the two largest active volcanoes of Europe (Mt. Vesuvius and Mt. Etna, respectively). Nevertheless, school programs are often inadequate about the natural hazards of the country. For this reason there are many requests from schoolteachers to visit with their classes the academic Institutions and to attend geophysical talks. The working group for educational activities of the Istituto Nazionale di Geofisica and Vulcanologia promotes and realizes Earth science outreach programs devoted to increase the knowledge of geophysical topics. The educational activity is one of the most important tasks of our Institution together with the research activities and the 24-hours survey of the Italian Seismic Network. The INGV hosts in its headquarter of Rome many visits of primary, secondary and high schools with an increasing demand year by year. Every year about 3,000 students visit our Institute over more than 60 open-days, and we participate to exhibitions and outreach projects organized by several Institutions. We show here what has been done at INGV for the geophysical education, underlining the problems and the successes of these activities. We describe also an educational project developed together with a teacher's team of secondary-school. Aim of this experience was to stimulate the interest of 12-year-old kids to unfamiliar arguments like seismology. The class was introduced to physical topics as waves and wave propagation by means of simple experiments. Then they visited the INGV were the research activities were shown, with emphasis on seismological studies; they were also thought how the Italian Seismic Network monitors earthquakes and how to use the P and S waves for their

  10. WATEQ3 geochemical model: thermodynamic data for several additional solids

    International Nuclear Information System (INIS)

    Krupka, K.M.; Jenne, E.A.

    1982-09-01

    Geochemical models such as WATEQ3 can be used to model the concentrations of water-soluble pollutants that may result from the disposal of nuclear waste and retorted oil shale. However, for a model to competently deal with these water-soluble pollutants, an adequate thermodynamic data base must be provided that includes elements identified as important in modeling these pollutants. To this end, several minerals and related solid phases were identified that were absent from the thermodynamic data base of WATEQ3. In this study, the thermodynamic data for the identified solids were compiled and selected from several published tabulations of thermodynamic data. For these solids, an accepted Gibbs free energy of formation, ΔG 0 /sub f,298/, was selected for each solid phase based on the recentness of the tabulated data and on considerations of internal consistency with respect to both the published tabulations and the existing data in WATEQ3. For those solids not included in these published tabulations, Gibbs free energies of formation were calculated from published solubility data (e.g., lepidocrocite), or were estimated (e.g., nontronite) using a free-energy summation method described by Mattigod and Sposito (1978). The accepted or estimated free energies were then combined with internally consistent, ancillary thermodynamic data to calculate equilibrium constants for the hydrolysis reactions of these minerals and related solid phases. Including these values in the WATEQ3 data base increased the competency of this geochemical model in applications associated with the disposal of nuclear waste and retorted oil shale. Additional minerals and related solid phases that need to be added to the solubility submodel will be identified as modeling applications continue in these two programs

  11. Geochemical characteristics of an urban river: Geochemical contamination and urban stream syndrome

    Science.gov (United States)

    MacAvoy, S. E.; Connor, N.; Sarraino, S.; Frantz, D.; Bushaw-Newton, K. L.

    2013-12-01

    The Anacostia River in Washington, D.C. is among the 10 most contaminated rivers in the USA, containing sewage, metals, PAHs, and PCBs. The biogeochemical characteristics of urban rivers, including the Anacostia, remain largely unstudied. Here we examine the base-flow geochemistry of the tidal freshwater Anacostia over a two-year period (April 2010- April 2012), concentrating on water chemistry (pH, hardness, SAR, alkalinity, Ca, Mg, Na, K, Fe, Mn, Zn, Al, Ba, Ni, P, S, Sr, NO3, NH4, PO4) at 3 locations in the stream. Mean NO3was generally between 1.1 and 1.3 mg/L, although occasionally concentrations increased to 3-4 mg/L at all sites. NH4 was very low generally (0.0 to 0.3 mg/L) with occasional peaks of 1.5-3.9 mg/L downstream. A Principle Components Analysis of stream chemistry showed that the upstream site had two components that explained 34.2 and 29.2% of the data variance; PC1 was most strongly negatively correlated with Ca (-.896), Mg (-.585) and hardness (-.823), and was positively correlated with Ba (which is sometimes associated with disturbance), B, NO3, P, PO4, Sr and Al. PC2 was strongly correlated with Mg, K, S, Ni and NH4. Na was positively and significantly correlated with both components, but more so with PC1. At the middle and downstream sites, two components explained 41 to 44% (PC1) and 22 to 28% (PC2) of the data set variance respectively. The components were essentially the same as the upstream site, with the dominance switched. PC1 was positively and highly correlated with ions associated with bedrock components (Ca, Mg, K, Na, and pH but also S and NH4). PC2 was not positively correlated with any of the dominant geochemical variables, but was negatively correlated with Ca and K and positively correlated with NO3, Ba and Mn. The principle components analysis suggests that there is a strong geochemical component and weaker anion/nitrate component contributing to the ion distribution, and their relative dominance changes moving downstream

  12. Oman Drilling Project Phase I Borehole Geophysical Survey

    Science.gov (United States)

    Matter, J. M.; Pezard, P. A.; Henry, G.; Brun, L.; Célérier, B.; Lods, G.; Robert, P.; Benchikh, A. M.; Al Shukaili, M.; Al Qassabi, A.

    2017-12-01

    holes BT1, GT3 and BA2 due to hole obstruction (e.g. collapsed borehole wall). Results from the geophysical survey including preliminary log analysis will be presented for each OmanDP Phase I borehole.

  13. The geophysical signal of the martian global dichotomy

    Science.gov (United States)

    Phillips, Roger J.

    1992-01-01

    A first-order tectonic question for Mars is the origin and nature of the global dichotomy (GD) separating approximately the northern and southern hemispheres of the planet. It is appropriate to focus on hypotheses for the origin of the GD as well as on geophysical models of related internal structure that are constrained by present-day observations. There are basic planetary scale observations that relate to the GD: (1) the dichotomy boundary separates two fundamentally different elevations on the planet, as the terrain to the north is lower by an average of about 3 km; (2) the boundary separates terrain of regionally distinct crater ages, heavily cratered (older) in the south and sparsely cratered (younger) in the north; (3) the amount of ancient crust apparently removed from north of the dichotomy boundary cannot be accounted for by simple surface erosion and deposition in the south, and the constraint becomes particularly severe if isostatic adjustment is presumed to have accompanied this process. This last point leads to the supposition that some type of interior process must have been responsible for the creation of the GD. An obvious way to create the observed elevation difference between the two hemispheres is with a thinner crust in the north, although a denser cust would also work. Hypotheses for producing a thinner northern crust include preferential sub-crustal erosion, a giant impact, and simply invoking the crustal thickness difference as a primordial feature of the planet. If the GD represents a fundamental change in the crustal thickness of Mars, then there should be geophysical evidence of this. The center-of-figure to center-of-mass offset of the planet may be related to the GD, but the Tharsis topography must certainly also contribute. If the Tharsis and GD effects can be separated, then a crustal thickness model can be tested, though the results will not be unique. The gravity field provides another geophysical constraint on GD models. A simple

  14. Establishing geochemical background variation and threshold values for 59 elements in Australian surface soil.

    Science.gov (United States)

    Reimann, Clemens; de Caritat, Patrice

    2017-02-01

    During the National Geochemical Survey of Australia over 1300 top (0-10cm depth) and bottom (~60-80cm depth) sediment samples (including ~10% field duplicates) were collected from the outlet of 1186 catchments covering 81% of the continent at an average sample density of 1 site/5200km 2 . The Australian surface soil. Different methods of obtaining geochemical threshold values, which differentiate between background and those samples with unusually high element concentrations and requiring attention, are presented and compared to Western Australia's 'ecological investigation levels' (EILs) established for 14 PTEs. For Mn and V these EILs are so low that an unrealistically large proportion (~24%) of the sampled sites would need investigation in Australia. For the 12 remaining elements (As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sn and Zn) few sample sites require investigation and as most of these are located far from human activity centres, they potentially suggest either minor local contamination or mineral exploration potential rather than pollution. No major diffuse source of contamination by PTEs affects Australian soil at the continental scale. Of the statistical methods used to establish geochemical threshold values, the most pertinent results come from identifying breaks in cumulative probability distributions, the Tukey inner fence and the 98th percentile. Geochemical threshold values for 59 elements, including emerging 'high-tech' critical elements such as lanthanides, Be, Ga or Ge, for which no EILs currently exist, are presented. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  15. Evaluation and combined geophysical interpretations of NURE and related geoscience data in the Van Horn, Pecos, Marfa, Fort Stockton, Presidido, and Emory Peak quadrangles, Texas. Volume 1. Final report

    International Nuclear Information System (INIS)

    Keller, G.R.; Hinze, W.J.; Aiken, C.L.V.; Goodell, P.C.; Roy, R.F.; Pingitore, N.E.

    1981-09-01

    This report (two volumes) is the culmination of a two-year study of the six Trans-Pecos Texas quadrangles (Van Horn, Pecos, Marfa, Fort Stockton, Presidio, and Emory Park) surveyed as part of the National Uranium Resource Evaluation (NURE) program. Volume I contains a discussion of the aeromagnetic, gravity and geochemical data, their processing, and their analysis. The geologic history and setting of the Trans-Pecos are discussed along with the uranium potential of the region. Uranium anomalies and occurrences characteristic of numerous different NURE classes are present in the study area, and information is presented on 33 drill holes into these targets. Volume II is a folio of maps reduced to a scale of 1:500,000. Geologic maps for each of the six quadrangles are included and the geophysical maps have been prepared to be overlays for the goelogic maps. In addition to the geologic maps, residual aeromagnetic anomaly, complete Bouguer gravity anomaly, flight line index, gravity station index, and anomaly interpretative maps were prepared for each quadrangle. A large suite of digitally processed maps of gravity and aeromagnetic data were prepared and are included in Volume II

  16. Evaluation and combined geophysical interpretations of NURE and related geoscience data in the Van Horn, Pecos, Marfa, Fort Stockton, Presidido, and Emory Peak quadrangles, Texas. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Keller, G.R.; Hinze, W.J.; Aiken, C.L.V.; Goodell, P.C.; Roy, R.F.; Pingitore, N.E.

    1981-09-01

    This report (two volumes) is the culmination of a two-year study of the six Trans-Pecos Texas quadrangles (Van Horn, Pecos, Marfa, Fort Stockton, Presidio, and Emory Park) surveyed as part of the National Uranium Resource Evaluation (NURE) program. Volume I contains a discussion of the aeromagnetic, gravity and geochemical data, their processing, and their analysis. The geologic history and setting of the Trans-Pecos are discussed along with the uranium potential of the region. Uranium anomalies and occurrences characteristic of numerous different NURE classes are present in the study area, and information is presented on 33 drill holes into these targets. Volume II is a folio of maps reduced to a scale of 1:500,000. Geologic maps for each of the six quadrangles are included and the geophysical maps have been prepared to be overlays for the goelogic maps. In addition to the geologic maps, residual aeromagnetic anomaly, complete Bouguer gravity anomaly, flight line index, gravity station index, and anomaly interpretative maps were prepared for each quadrangle. A large suite of digitally processed maps of gravity and aeromagnetic data were prepared and are included in Volume II.

  17. Overview of Effective Geophysical Methods Used in the Study of ...

    African Journals Online (AJOL)

    combined data analysis techniques as a means to enhance the characterization effort. In addition, it is ... coincided with improvements in the resolution, acquisition and interpretation of. Geophysical Data. This process is ongoing; therefore, outlines of Geophysical. Techniques .... vibrations, large line lengths are needed.

  18. Solar Wind Monitor--A School Geophysics Project

    Science.gov (United States)

    Robinson, Ian

    2018-01-01

    Described is an established geophysics project to construct a solar wind monitor based on a nT resolution fluxgate magnetometer. Low-cost and appropriate from school to university level it incorporates elements of astrophysics, geophysics, electronics, programming, computer networking and signal processing. The system monitors the earth's field in…

  19. Rožňava ore field - geophysical works

    Directory of Open Access Journals (Sweden)

    Géczy Július

    1998-12-01

    Full Text Available The article prowides a review of geophysical works in the ore field Rožňava conducted up to date. Magnetometric and geoelectric methods and gravimetric measurements have been used. Geophysical works were focused to the solving regional problems whose contribution to the prospecting of vein deposits is not essential.

  20. Introduction to the JEEG Agricultural Geophysics special issue

    Science.gov (United States)

    Recent advancements such as the availability of personal computers, technologies to store/process large amounts of data, the GPS, and GIS have now made geophysical methods practical for agricultural use. Consequently, there has been a rapid expansion of agricultural geophysics research just over the...

  1. Investigation of novel geophysical techniques for monitoring CO2 movement during sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Hoversten, G. Michael; Gasperikova, Erika

    2003-10-31

    Cost effective monitoring of reservoir fluid movement during CO{sub 2} sequestration is a necessary part of a practical geologic sequestration strategy. Current petroleum industry seismic techniques are well developed for monitoring production in petroleum reservoirs. The cost of time-lapse seismic monitoring can be born because the cost to benefit ratio is small in the production of profit making hydrocarbon. However, the cost of seismic monitoring techniques is more difficult to justify in an environment of sequestration where the process produces no direct profit. For this reasons other geophysical techniques, which might provide sufficient monitoring resolution at a significantly lower cost, need to be considered. In order to evaluate alternative geophysical monitoring techniques we have undertaken a series of numerical simulations of CO{sub 2} sequestration scenarios. These scenarios have included existing projects (Sleipner in the North Sea), future planned projects (GeoSeq Liberty test in South Texas and Schrader Bluff in Alaska) as well as hypothetical models based on generic geologic settings potentially attractive for CO{sub 2} sequestration. In addition, we have done considerable work on geophysical monitoring of CO{sub 2} injection into existing oil and gas fields, including a model study of the Weyburn CO{sub 2} project in Canada and the Chevron Lost Hills CO{sub 2} pilot in Southern California (Hoversten et al. 2003). Although we are specifically interested in considering ''novel'' geophysical techniques for monitoring we have chosen to include more traditional seismic techniques as a bench mark so that any quantitative results derived for non-seismic techniques can be directly compared to the industry standard seismic results. This approach will put all of our finding for ''novel'' techniques in the context of the seismic method and allow a quantitative analysis of the cost/benefit ratios of the newly

  2. Avalanches in functional materials and geophysics

    CERN Document Server

    Saxena, Avadh; Planes, Antoni

    2017-01-01

    This book provides the state-of-the art of the present understanding of avalanche phenomena in both functional materials and geophysics. The main emphasis of the book is analyzing these apparently different problems within the common perspective of out-of-equilibrium phenomena displaying spatial and temporal complexity that occur in a broad range of scales. Many systems, when subjected to an external force, respond intermittently in the form of avalanches that often span over a wide range of sizes, energies and durations. This is often related to a class of critical behavior characterized by the absence of characteristic scales. Typical examples are magnetization processes, plastic deformation and failure occuring in functional materials. These phenomena share many similarities with seismicity arising from the earth crust failure due to stresses that originate from plate tectonics.

  3. Geophysical examinations of deposits and old sites

    International Nuclear Information System (INIS)

    1991-01-01

    Geomagnetic total field measurements by proton magnetometers with memories form the systematic exploration of suspected surfaces of old sites and old sites of an important, flexible and reasonably priced geophysical process. From experience, there are two important main applications. These are firstly the detailed work on location problems jointly with and supplementing multi-temporal evaluations of the air picture and secondly to locate iron in deposits. The particular advantage of geo-magnetics is that even in the most difficult measurement conditions, with the aid of the suitable analytical method evaluation, clear results and practically usable information can be obtained. In comparison with this, other high resolution methods of measurement, such as electromagnetic charting, for example (problem of integral anomaly pictures which cannot be evaluated) and geo-radar (loam covering, trickled water saturation) are limited to a considerably narrower measurement and evaluation spectrum in practical applications. (orig.) [de

  4. Multigroup neutron data base for nuclear geophysics

    International Nuclear Information System (INIS)

    Dworak, D.; Loskiewicz, J.

    1989-01-01

    The average group constants for the total, elastic, inelastic and capture cross sections as well as the average cosine of the scattering angle for elastic scattering and the average logarithmic energy decrement for elastic scattering have been obtained at two temperatures (300 and 400 deg K), using the ENDF/B-4 data and the IAEA-NDS pre-processing codes. The extended Abagyan group structure and the weighting spectrum of type 1/E were applied in course of the calculations. Self-shielding effect was not taken into account. All cross sections were Doppler broadened for both, 300 and 400 deg K temperatures. Under above assumptions, the average group constants were obtained for exactly 22 ENDF materials, which are of special importance for nuclear geophysics applications. 10 refs., 15 figs., 44 tabs. (author)

  5. Cosmic Muon Detection for Geophysical Applications

    Directory of Open Access Journals (Sweden)

    László Oláh

    2013-01-01

    Full Text Available A portable cosmic muon detector has been developed for environmental, geophysical, or industrial applications. The device is a tracking detector based on the Close Cathode Chamber, an MWPC-like technology, allowing operation in natural underground caves or artificial tunnels, far from laboratory conditions. The compact, low power consumption system with sensitive surface of 0.1 m2 measures the angular distribution of cosmic muons with a resolution of 10 mrad, allowing for a detailed mapping of the rock thickness above the muon detector. Demonstration of applicability of the muon telescope (REGARD Muontomograph for civil engineering and measurements in artificial underground tunnels or caverns are presented.

  6. The geology and geophysics of Mars

    Science.gov (United States)

    Saunders, R. S.

    1976-01-01

    The current state of knowledge concerning the regional geology and geophysics of Mars is summarized. Telescopic observations of the planet are reviewed, pre-Mariner models of its interior are discussed, and progress achieved with the Mariner flybys, especially that of Mariner 9, is noted. A map of the Martian geological provinces is presented to provide a summary of the surface geology and morphology. The contrast between the northern and southern hemispheres is pointed out, and the characteristic features of the surface are described in detail. The global topography of the planet is examined along with its gravitational field, gravity anomalies, and moment of inertia. The general sequence of events in Martian geological history is briefly outlined.

  7. Geophysical methods in radon risk studies.

    Science.gov (United States)

    Wysocka, Malgorzata; Kotyrba, Andrzej; Chalupnik, Stanislaw; Skowronek, Jan

    2005-01-01

    The results of the studies presented in the paper have shown that in the Upper Silesian Region in Poland, radon indoor concentration levels depend first of all on the geological structure of the subsurface layers. The essential factors influencing radon migration ability are the mining-induced transformations of a rock mass. In some cases, significant variations of radon potential have been found at sites featuring similar geological structures and experiencing comparable mining effects. To find out the causes of these variations, studies involving geophysical methods such as electrical resistivity profiling (PE) and electrical resisitivity sounding (VES) were used. These studies have shown that the measurements made using the electrical resistivity method can be helpful in evaluating radon potential of both the tectonically disturbed areas and the mining-transformed ones.

  8. Geophysical characterization of contaminated muddy sediments

    International Nuclear Information System (INIS)

    McDermott, I. R.; English, G. E.

    1997-01-01

    A non-intrusive, seismic subbottom profile survey of pond sediments was conducted on a former U.S.Naval Facility at Argentia, Newfoundland, to characterize the nature and extent of contamination. An IKB Seistec boomer was used in conjunction with C-CORE's HI-DAPT digital data acquisition and processing system and differential GPS system. The survey was successful in locating regions of soft muddy sediments and in determining the thickness of these deposits. Subsurface buried objects, which are potential sources of pollution, were also identified. Intrusive profiling of the sediment was done with a new tool, the Soil Stiffness Probe, which combines two geophysical measurement systems to determine bulk density and shear stiffness. The muddy sediments were found to be highly 'fluidized', indicating that they could be easily removed with a suction dredge. 4 refs., 5 figs

  9. Symmetries in geology and geophysics

    Science.gov (United States)

    Turcotte, Donald L.; Newman, William I.

    1996-01-01

    Symmetries have played an important role in a variety of problems in geology and geophysics. A large fraction of studies in mineralogy are devoted to the symmetry properties of crystals. In this paper, however, the emphasis will be on scale-invariant (fractal) symmetries. The earth’s topography is an example of both statistically self-similar and self-affine fractals. Landforms are also associated with drainage networks, which are statistical fractal trees. A universal feature of drainage networks and other growth networks is side branching. Deterministic space-filling networks with side-branching symmetries are illustrated. It is shown that naturally occurring drainage networks have symmetries similar to diffusion-limited aggregation clusters. PMID:11607719

  10. Geophysical couples” Discuss jobs, marriage

    Science.gov (United States)

    Some 90 participants attended an open forum, “Dual Career Couples: Challenges and Opportunities,” on December 9 at the AGU Fall 1991 Meeting in San Francisco. Several couples summarized their experiences in “geophysical marriages” while the audience contributed questions and comments.Being forced to live apart was a common complaint among the married panelists. One couple on the panel—Karen Prestegaard of the University of Maryland and Jim Luhr of the Smithsonian Institution's Department of Mineral Physics—have been able to live together only 2 years out of the last 10. Although employer guidelines do not officially prohibit hiring couples, Prestegaard and Luhr expressed frustration that many institutions not only will not do so, but also will not help the second partner find a job nearby.

  11. Is formamide a geochemically plausible prebiotic solvent?

    Science.gov (United States)

    Bada, Jeffrey L; Chalmers, John H; Cleaves, H James

    2016-07-27

    From a geochemical perspective, significant amounts of pure formamide (HCONH2) would have likely been rare on the early Earth. There may have been mixed formamide-water solutions, but even in the presence of catalyst, solutions with >20 weight% water in formamide would not have produced significant amounts of prebiotic compounds. It might be feasible to produce relatively pure formamide by a rare occurrence of freezing formamide/water mixtures at temperatures lower than formamide's freezing point (2.55 °C) but greater than the freezing point of water. Because of the high density of formamide ice it would have sunk and accumulated at the bottom of the solution. If the remaining water froze on the surface of this ice, and was then removed by a sublimation-ablation process, a small amount of pure formamide ice might have been produced. In addition a recent report suggested that ∼85 weight% formamide could be prepared by a geochemical type of fractional distillation process, offering another possible route for prebiotic formamide production.

  12. Geochemical signature of radioactive waste: oil NORM

    International Nuclear Information System (INIS)

    Costa, Gilberto T. de Paula; Costa-de-Moura, Jorge; Gomes, Carlos de Almeida; Sampaio, Emidio A. Lopes

    2017-01-01

    The Brazilian Nuclear Agency (CNEN) rules all nuclear activity in Brazil as demanded by the Federal Constitution, articles 21, XXIII, and 177, V, and by the Federal Acts 4.118/62 and 10.308/2001. Therefore, the CNEN is responsible for any radioactive waste disposal in the country. Oil Naturally Occurring Radioactive Materials (Oil NORM) in this paper refers to waste coming from oil exploration. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for each oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is a specific geochemical modeling of oil sludge NORM samples which are analyzed for radioisotopes normally present in oil pipes, such as 228 Ac, 214 Bi and 214 Pb. The activity ratios are plotted in scatter diagrams. This method was successfully tested with data of different sources obtained from analysis reports from the Campos Basin/Brazil and from literature. (author)

  13. Geochemical signature of radioactive waste: oil NORM

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Gilberto T. de Paula; Costa-de-Moura, Jorge; Gomes, Carlos de Almeida; Sampaio, Emidio A. Lopes, E-mail: gilberto.costa@cnen.gov.br, E-mail: jcmoura@cnen.gov.br, E-mail: cgomes@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Div. de Controle de Rejeitos e Transporte de Materiais Radioativos

    2017-07-01

    The Brazilian Nuclear Agency (CNEN) rules all nuclear activity in Brazil as demanded by the Federal Constitution, articles 21, XXIII, and 177, V, and by the Federal Acts 4.118/62 and 10.308/2001. Therefore, the CNEN is responsible for any radioactive waste disposal in the country. Oil Naturally Occurring Radioactive Materials (Oil NORM) in this paper refers to waste coming from oil exploration. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for each oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is a specific geochemical modeling of oil sludge NORM samples which are analyzed for radioisotopes normally present in oil pipes, such as {sup 228}Ac, {sup 214}Bi and {sup 214}Pb. The activity ratios are plotted in scatter diagrams. This method was successfully tested with data of different sources obtained from analysis reports from the Campos Basin/Brazil and from literature. (author)

  14. When tsunamology and geophysics clash, throw geophysics in the trash (Sergey Soloviev Medal Lecture)

    Science.gov (United States)

    Synolakis, Costas

    2014-05-01

    Tsunami science has evolved differently from research on other extreme natural hazards, primarily because of the unavailability, until recently, of instrumental recordings of tsunamis in the open ocean. Recordings and observations have catapulted tsunamology into a rapidly evolving high-interdisciplinary field spanning geology, geophysics, oceanography, coastal engineering, hydrodynamics and social science. I will discuss progress in tsunami geology and geophysics in the past thirty years, and describe the evolution of numerical codes and analytical results. I will describe field observations which, while counter-intuitive at first, they later helped explain complex dynamics and assisted us in improving tsunami hazard mitigation. While the grand science synthesis remains elusive, we are converging to where we can reduce tsunami-related fatalities and injuries by about one half in the next few years.

  15. Geochemical exploration for phosphate in the State of Acre

    International Nuclear Information System (INIS)

    Costa, M.L. da; Melo Costa, W.A. de; Santos, A.J.M. dos

    1989-01-01

    The geochemical prospecting conducted for phosphates in Acre which could explain the good fertility of the region was charged to discover this material. The phosphates are strictly built of all the bone structures and coprolites of the several fragments of vertebrate fossils, which are widespread in the region. The phosphatic fossils are bedded in the Solimoes Formation, especially its basal to intermediary conglomeratic bed. The fossils are constituted of low crystallinity apatite, and their matrix sediments include quartz, feldspars, smectite, halloysite and calcite. The P 2 O 5 content reaches up to 5% in the sediments and up to 32% in the fragments. The fossils are enriched in U 3 O 8 and rare earth elements. There is no perspect of classic or mineral deposits but the geological knowlwdge will permit the improvement of the use of the soils in Acre. (author) [pt

  16. Hydrogeological and geochemical studies in the Perch Lake basin

    International Nuclear Information System (INIS)

    Barry, P.J.

    1979-08-01

    The Perch Lake basin is a small drainage system along the Ottawa River about 200 km west of Ottawa on the Canadian Shield. Since 1975, groups of scientists from several Canadian universities and government departments have been studying the hydrological, geological and geochemical properties of the basin. The object of these studies is to develop and test simulation models used to describe the time-dependent mass flow rates of water and dissolved and suspended substances through the basin. To review progress, a symposium/workshop was held at Chalk Rier in 1978 April. This report contains 24 extended summaries of the material presented verbally at the workshop. Subject matters include atmospheric sources and sinks, mass flows through the surface and subsurface regimes in the drainage basins and interactions occurring in the lake. (author)

  17. Joint inversion of geophysical data for site characterization and restoration monitoring. 1998 annual progress report

    International Nuclear Information System (INIS)

    Berge, P.A.; Berryman, J.G.; Roberts, J.J.; Wildenschild, D.

    1998-01-01

    'The purpose of this project is to develop a computer code for joint inversion of seismic and electrical data, to improve underground imaging for site characterization and remediation monitoring. The computer code developed in this project will invert geophysical data to obtain direct estimates of porosity and saturation underground, rather than inverting for seismic velocity and electrical resistivity or other geophysical properties. This is intended to be a significant improvement in the state-of-the-art of underground imaging, since interpretation of data collected at a contaminated site would become much less subjective. Potential users include DOE scientists and engineers responsible for characterizing contaminated sites and monitoring remediation of contaminated sites. In this three-year project, the authors use a multi-phase approach consisting of theoretical and numerical code development, laboratory investigations, testing on available laboratory and borehole geophysics data sets, and a controlled field experiment, to develop practical tools for joint electrical and seismic data interpretation. This report summarizes work after about 1.7 years of a 3-year project. Progress on laboratory measurements is described first, followed by progress on developing algorithms for the inversion code to relate geophysical data to porosity and saturation.'

  18. Temporal associations of life with solar and geophysical activity

    Directory of Open Access Journals (Sweden)

    T. K. Breus

    Full Text Available In biology, circadian rhythms with a period of one cycle in 20–28 h are known to be ubiquitous and partly endogenous. Rhythms with a frequency lower than one cycle per day are called 'infradian rhythms'. Among them are components with one cycle in about 3.5, 7, 14 and 28 days, the multiseptans, which, like the circadians, must be regarded as a general characteristic of life: they characterize unicells as well as much more differentiated organisms. We hypothesize that heliogeophysical factors other than the solar visible light, held responsible for the evolution of circadian periodicity, underlie the infradian rhythms of biosystems. The periodicities in the solar wind and variations in the interplanetary magnetic field (IMF which are associated with the solar rotation are very similar in length to the biological periodicities. We investigate the temporal relations of variations in solar activity and in biological systems to test associations between events in the IMF, in geomagnetic disturbance, in myocardial infarction and in physiology. By cross-spectral analysis, we also find relations at certain frequencies between changes in human physiology on the one hand, and (1 the vertical component of the induction vector of the IMF, Bz, and (2 a global index of geomagnetic disturbance, Kp, on the other hand. We wish to stimulate interest in these periodicities of both biological systems and geophysical endpoints among physicists and biologists alike, so that problems relevant to clinicians and other biologists, including evolutionists, are eventually solved by their cooperation with the geophysical community.

  19. Water-Energy-Food Nexus: Compelling Issues for Geophysical Research

    Science.gov (United States)

    Akhbari, M.; Grigg, N. S.; Waskom, R.

    2014-12-01

    The joint security of water, food, and energy systems is an urgent issue everywhere, and strong drivers of development and land use change, exacerbated by climate change, require new knowledge to achieve integrated solution using a nexus-based approach to assess inter-dependencies. Effective research-based decision support tools are essential to identify the major issues and interconnections to help in implementation of the nexus approach. The major needs are models and data to clearly and unambiguously present decision scenarios to local cooperative groups of farmers, electric energy generators and water officials for joint decisions. These can be developed by integrated models to link hydrology, land use, energy use, cropping simulation, and optimization with economic objectives and socio-physical constraints. The first step in modeling is to have a good conceptual model and then to get data. As the linking of models increases uncertainties, each one should be supplied with adequate data at suitable spatial and temporal resolutions. Most models are supplied with data by geophysical scientists, such as hydrologists, geologists, atmospheric scientists, soil scientists, and climatologists, among others. Outcomes of a recently-completed project to study the water-energy-food nexus will be explained to illuminate the model and data needs to inform future management actions across the nexus. The project included a workshop of experts from government, business, academia, and the non-profit sector who met to define and explain nexus interactions and needs. An example of the findings is that data inconsistencies among sectors create barriers to integrated planning. A nexus-based systems model is needed to outline sectoral inter-dependencies and identify data demands and gaps. Geophysical scientists can help to create this model and take leadership on designing data systems to facilitate sharing and enable integrated management.

  20. Geochemical Constraints on Archaeal Diversity in the Vulcano Hydrothermal System

    Science.gov (United States)

    Rogers, K. L.; Amend, J. P.

    2006-12-01

    The shallow marine hydrothermal system of Vulcano, Italy hosts a wide diversity of cultured thermophilic Archaea, including Palaeococcus helgesonii, Archaeoglobus fulgidus, and Pyrococcus furiosus, to name a few. However, recent studies have revealed a plethora of uncultured archaeal lineages in the Vulcano system. For example, a 16S rRNA gene survey of an onshore geothermal well identified a diverse archaeal community including deeply-branching uncultured Crenarchaeota, Korarchaeota, and Euryarchaeota. Additionally, culture-independent hybridization techniques suggested that Archaea account for nearly half of the microbial community in the Vulcano system. Furthermore, geochemical characterization of fluids revealed numerous lithotrophic and heterotrophic exergonic reactions that could support as yet uncultured organisms. Archaeal diversity throughout the Vulcano hydrothermal system was investigated using 16S rRNA gene surveys at five submarine vents and an onshore sediment seep. Overall, archaeal diversity was higher (10 groups) at submarine vents with moderate temperatures (59°C) compared with higher temperature (94°C) vents (4 groups). Archaeal communities at the moderately thermal vents were dominated by Thermococcales and also contained Archaeoglobales, Thermoproteales, and uncultured archaea among the Korarchaeota, Marine Group I, and the Deep-sea Hydrothermal Vent Euryarchaeota (DHVE). Fluid composition also affects the microbial community structure. At two high-temperature sites variations in archaeal diversity can be attributed to differences in iron and hydrogen concentrations, and pH. Comparing sites with similar temperature and pH conditions suggests that the presence of Desulfurococcales is limited to sites at which metabolic energy yields exceed 10 kJ per mole of electrons transferred. The Vulcano hydrothermal system hosts diverse archaeal communities, containing both cultured and uncultured species, whose distribution appears to be constrained by

  1. Radioactive waste isolation in salt: peer review of the Office of Nuclear Waste Isolation's Geochemical Program Plan

    International Nuclear Information System (INIS)

    Harrison, W.; Seitz, M.; Fenster, D.; Lerman, A.; Brookins, D.; Tisue, M.

    1984-02-01

    Describe the management program for coordinating subcontractors and their work, and integrating research results. Appropriate flowcharts should be included. Provide more information on the overall scope of the program. For each subcontractor, provide specific workscopes that indicate whether analytical activities are developmental or routine, approximate number of analyses to be made, and something of the adequacy of the analyses to meet program goals. Indicate interfaces with other earth-science disciplines like hydrology and with other groups doing relevant geochemical research and engineering design. Address the priorities for each activity or group of activities. High priority should be given to early development of a geochemical statement of what constitutes suitable salt for a repository. Reference standard procedures for sampling, sample preservation, and sample analysis wherever appropriate or, if not appropriate, indicate that any deviations from standard procedures will be documented. Ensure that appropriate quality assurance procedures will be followed for the procedures listed above. Include specific procedures for the choice, verification, validation, and documentation of computer codes related to the geochemical aspects of repository performance assessment. Include activities addressing regional hydrochemistry and make clear that each principal hydrogeologic unit at each site will be studied geochemically. Indicate that proposed plans for obtaining hydrogeochemical data will be included in each site characterization plan. Describe how site geochemical stability will be handled, especially with respect to dissolution, postemplacement geochemistry, human influences, and climatic variations. Minor recommendations and suggested improvements in the text of the plan are given in Sec. 5

  2. Geochemical analysis of core from a geothermal anomaly

    International Nuclear Information System (INIS)

    Haverslew, B.; Tammemagi, H.Y.

    1985-04-01

    A mild geothermal area in western Montana, USA, has been studied, as a natural analog, to learn about the effects that long-term heat generated by a repository containing spent nuclear fuel might have on the surrounding rock mass. The results of previous geological, geophysical and hydrogeological studies are briefly summarized. Extensive petrological studies have been undertaken on core samples obtained from a 2 km deep borehole drilled into the Empire Creek Stock. These include a detailed petrographic study, x-ray diffraction analyses, scanning electron microscope and electron microprobe analyses, porosity and permeability measurements, oxygen isotope analyses, uranium disequilibrium analyses and K-Ar age determinations. The implications to deep burial of nuclear wastes are discussed. 40 refs

  3. mineralogical and geochemical trends in lateritic weathering profiles ...

    African Journals Online (AJOL)

    Three soil profiles on the basement rocks in Awa-Oru-Ijebu Igbo area of southwestern Nigeria were investigated for the ... Geochemical data further revealed significant enrichment of Al2O3 and Fe2O3 in the laterite profile compared with the parent rock, ...... Mineralogical, Geochemical and Economic. Appraisal of some clay ...

  4. Behaviour of nature and technogenic radioisotopes in buried geochemical barriers

    International Nuclear Information System (INIS)

    Kuznetsov, V.A.; Onoshko, M.P.; Generalova, V.A.

    1998-01-01

    Behaviour of potassium 40, radium 226, thorium 232, strontium 90 and cesium 137 on geochemical barriers connected with buried soils and cut-off meander sediments of the Holocene age of the Sozh river valley are examined. Some sides of the barrier geochemical structure caused by syngeneic and epigenetic processes have been taken into consideration

  5. Strategies for improving the resolution of electrical and electromagnetic geophysical measurements for three-dimensional inverse modeling of CO2 movement

    Science.gov (United States)

    Commer, M.; Kowalsky, M. B.; Dafflon, B.; Wu, Y.; Hubbard, S. S.

    2013-12-01

    Geologic carbon sequestration is being evaluated as a means to mitigate the effects of greenhouse gas emissions. Efforts are underway to identify adequate reservoirs and to evaluate the behavior of injected CO2 over time; time-lapse geophysical methods are considered effective tools for these purposes. Pilot studies have shown that the invasion of CO2 into a background pore fluid can alter the electrical resistivity, with increases from CO2 in the super-critical or gaseous phase, and decreases from CO2 dissolved in groundwater (especially when calcite dissolution is occurring). Because of their sensitivity to resistivity changes, electrical and electromagnetic (EM) methods have been used in such studies for indirectly assessing CO2 saturation changes. While the electrical resistance tomography (ERT) method is a well-established technique for both crosswell and surface applications, its usefulness is limited by the relatively low-resolution information it provides. Controlled-source EM methods, including both frequency-domain and time-domain (transient EM) methods, can offer improved resolution. We report on three studies that aim to maximize the information content of electrical and electromagnetic measurements in inverse modeling applications that target the monitoring of resistivity changes due to CO2 migration and/or leakage. The first study considers a three-dimensional crosswell data set collected at an analogue site used for investigating CO2 distribution and geochemical reactivity within a shallow formation. We invert both resistance and phase data using a gradient-weighting method for descent-based inversion algorithms. This method essentially steers the search direction in the model space using low-cost non-linear conjugate gradient methods towards the more computationally expensive Gauss-Newton direction. The second study involves ERT data that were collected at the SECARB Cranfield site near Natchez, Mississippi, at depths exceeding 3000 m. We employ a

  6. Immersive, hands-on, team-based geophysical education at the University of Texas Marine Geology and Geophysics Field Course

    Science.gov (United States)

    Saustrup, S.; Gulick, S. P.; Goff, J. A.; Davis, M. B.; Duncan, D.; Reece, R.

    2013-12-01

    The University of Texas Institute for Geophysics (UTIG), part of the Jackson School of Geosciences, annually offers a unique and intensive three-week marine geology and geophysics field course during the spring/summer semester intersession. Now entering its seventh year, the course transitions students from a classroom environment through real-world, hands-on field acquisition, on to team-oriented data interpretation, culminating in a professional presentation before academic and industry employer representatives. The course is available to graduate students and select upper-division undergraduates, preparing them for direct entry into the geoscience workforce or for further academic study. Geophysical techniques used include high-resolution multichannel seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, sediment coring, grab sampling, data processing, and laboratory analysis of sediments. Industry-standard equipment, methods, software packages, and visualization techniques are used throughout the course, putting students ahead of many of their peers in this respect. The course begins with a 3-day classroom introduction to the field area geology, geophysical methods, and computing resources used. The class then travels to the Gulf Coast for a week of hands-on field and lab work aboard two research vessels: UTIG's 22-foot, aluminum hulled Lake Itasca; and NOAA's 82-foot high-speed catamaran R/V Manta. The smaller vessel handles primarily shallow, inshore targets using multibeam bathymetry, sidescan sonar, and grab sampling. The larger vessel is used both inshore and offshore for multichannel seismic, CHIRP profiling, multibeam bathymetry, gravity coring, and vibracoring. Field areas to date have included Galveston and Port Aransas, Texas, and Grand Isle, Louisiana, with further work in Grand Isle scheduled for 2014. In the field, students work in teams of three, participating in survey design, instrument set-up, field deployment

  7. Estimation of Supraglacial Dust and Debris Geochemical Composition via Satellite Reflectance and Emissivity

    Directory of Open Access Journals (Sweden)

    Kimberly Casey

    2012-09-01

    Full Text Available We demonstrate spectral estimation of supraglacial dust, debris, ash and tephra geochemical composition from glaciers and ice fields in Iceland, Nepal, New Zealand and Switzerland. Surface glacier material was collected and analyzed via X-ray fluorescence spectroscopy (XRF and X-ray diffraction (XRD for geochemical composition and mineralogy. In situ data was used as ground truth for comparison with satellite derived geochemical results. Supraglacial debris spectral response patterns and emissivity-derived silica weight percent are presented. Qualitative spectral response patterns agreed well with XRF elemental abundances. Quantitative emissivity estimates of supraglacial SiO2 in continental areas were 67% (Switzerland and 68% (Nepal, while volcanic supraglacial SiO2 averages were 58% (Iceland and 56% (New Zealand, yielding general agreement. Ablation season supraglacial temperature variation due to differing dust and debris type and coverage was also investigated, with surface debris temperatures ranging from 5.9 to 26.6 C in the study regions. Applications of the supraglacial geochemical reflective and emissive characterization methods include glacier areal extent mapping, debris source identification, glacier kinematics and glacier energy balance considerations.

  8. Geophysical assessments of renewable gas energy compressed in geologic pore storage reservoirs.

    Science.gov (United States)

    Al Hagrey, Said Attia; Köhn, Daniel; Rabbel, Wolfgang

    2014-01-01

    Renewable energy resources can indisputably minimize the threat of global warming and climate change. However, they are intermittent and need buffer storage to bridge the time-gap between production (off peak) and demand peaks. Based on geologic and geochemical reasons, the North German Basin has a very large capacity for compressed air/gas energy storage CAES in porous saltwater aquifers and salt cavities. Replacing pore reservoir brine with CAES causes changes in physical properties (elastic moduli, density and electrical properties) and justify applications of integrative geophysical methods for monitoring this energy storage. Here we apply techniques of the elastic full waveform inversion FWI, electric resistivity tomography ERT and gravity to map and quantify a gradually saturated gas plume injected in a thin deep saline aquifer within the North German Basin. For this subsurface model scenario we generated different synthetic data sets without and with adding random noise in order to robust the applied techniques for the real field applications. Datasets are inverted by posing different constraints on the initial model. Results reveal principally the capability of the applied integrative geophysical approach to resolve the CAES targets (plume, host reservoir, and cap rock). Constrained inversion models of elastic FWI and ERT are even able to recover well the gradual gas desaturation with depth. The spatial parameters accurately recovered from each technique are applied in the adequate petrophysical equations to yield precise quantifications of gas saturations. Resulting models of gas saturations independently determined from elastic FWI and ERT techniques are in accordance with each other and with the input (true) saturation model. Moreover, the gravity technique show high sensitivity to the mass deficit resulting from the gas storage and can resolve saturations and temporal saturation changes down to ±3% after reducing any shallow fluctuation such as that of

  9. Methodological approaches in estimating anomalous geochemical field structure

    International Nuclear Information System (INIS)

    Gavrilov, R; Rudmin, M

    2015-01-01

    Mathematical statistic methods were applied to analyze the core samples from vertical expendable wells in Chertovo Koryto gold ore field. The following methods were used to analyse gold in samples: assay tests and atomic absorption method (AAS), while emission spectrum semiquantative method was applied to identify traces. The analysis of geochemical association distribution in one central profile demonstrated that bulk metasomatic aureoles are characteristic of concentric zonal structure. The distribution of geochemical associations is correlated to the hydrothermal stages of mineral formation identified in this deposit. It was proved that the processed geochemical data by factor and cluster analyses provided additional information on the anomalous geochemical field structure in gold- bearing black-shale strata. Such methods are effective tools in interpretating specific features of geochemical field structures in analogous potential ore-bearing areas

  10. Analysis of Geophysical Logs From Six Boreholes at Lariat Gulch, Former U.S. Air Force Site PJKS, Jefferson County, Colorado

    National Research Council Canada - National Science Library

    Paillet, Frederick L; Hodges, Richard E; Corland, Barbara S

    2002-01-01

    .... Air Force site PJKS in Jefferson County near Denver, Colorado. Geophysical logs include gamma, normal resistivity, fluid-column temperature and resistivity, caliper, televiewer, and heat-pulse flowmeter...

  11. What's down below? Current and potential future applications of geophysical techniques to identify subsurface permafrost conditions (Invited)

    Science.gov (United States)

    Douglas, T. A.; Bjella, K.; Campbell, S. W.

    2013-12-01

    For infrastructure design, operations, and maintenance requirements in the North the ability to accurately and efficiently detect the presence (or absence) of ground ice in permafrost terrains is a serious challenge. Ground ice features including ice wedges, thermokarst cave-ice, and segregation ice are present in a variety of spatial scales and patterns. Currently, most engineering applications use borehole logging and sampling to extrapolate conditions at the point scale. However, there is high risk of over or under estimating the presence of frozen or unfrozen features when relying on borehole information alone. In addition, boreholes are costly, especially for planning linear structures like roads or runways. Predicted climate warming will provide further challenges for infrastructure development and transportation operations where permafrost degradation occurs. Accurately identifying the subsurface character in permafrost terrains will allow engineers and planners to cost effectively create novel infrastructure designs to withstand the changing environment. There is thus a great need for a low cost rapidly deployable, spatially extensive means of 'measuring' subsurface conditions. Geophysical measurements, both terrestrial and airborne, have strong potential to revolutionize our way of mapping subsurface conditions. Many studies in continuous and discontinuous permafrost have used geophysical measurements to identify discrete features and repeatable patterns in the subsurface. The most common measurements include galvanic and capacitive coupled resistivity, ground penetrating radar, and multi frequency electromagnetic induction techniques. Each of these measurements has strengths, weaknesses, and limitations. By combining horizontal geophysical measurements, downhole geophysics, multispectral remote sensing images, LiDAR measurements, and soil and vegetation mapping we can start to assemble a holistic view of how surface conditions and standoff measurements

  12. Petrographic and geochemical characteristics of the Cypress Creek salt core

    International Nuclear Information System (INIS)

    1983-07-01

    Law Engineering Testing Company supervised the drilling of a corehole into the stock of Cypress Creek Dome, located in Perry County, Mississippi. A total of 170 ft of caprock and 501 ft of salt stock was recovered for physical examination and chemical analysis. This report describes the types of analyses performed and summarizes the data developed. The entire caprock and salt core were described and photographed prior to selection of samples for petrologic and geochemical analysis. Transmitted light techniques were used to determine gross structural and compositional variations in the core. The core lithologies are presented graphically, at a scale of 1 in. to 2 ft. In addition to the detailed field descriptions and photographs, petrologic studies performed on selected caprock and salt samples included: thin-section examination, scanning-electron microscope studies, energy-dispersion analysis, and x-ray-diffraction analysis. Geochemical analyses were performed to determine the average elemental composition of the salt core and amounts of methane and carbon dioxide gases contained within the salt grains. Except for two thin (3 and 6 ft thick) gypsum zones in the top 27 ft of the caprock, the core is predominantly anhydrite (generally 80%). Minor amounts of dolomite and calcite are also present. The salt core consists predominantly of crystalline halite, fine- to medium-grained (0.25 to 1 in.) with few megacrysts. Anhydrite occurs in the salt core as disseminated grains, ranging in length from <0.1 in. to 12 in. Discrete zones exist within the salt core, distinguished from one another primarily by the character of the anhydrite inclusions

  13. Integrated Geochemical-Petrographic Insights on Neoproterozoic Ocean Oxygenation

    Science.gov (United States)

    Hood, A.; Planavsky, N.; Wallace, M. W.; Wang, X.; Gueguen, B.

    2015-12-01

    Novel isotope systems have the potential to provide new insights into biogeochemical cycling in Earth's evolving oceans. However, much recent paleo-redox work has been done without extensive consideration of sample preservation or paleoenvironmental setting. Neoproterozoic reef complexes from South Australia provide a perfect setting to test geochemical redox proxies (e.g. uranium isotopes and trace metal chemistry) within a well-defined sedimentological and petrographic context. These reefs developed significant frameworks over ~1km of steep platform relief from the seafloor, and contain a variety of carbonate components including primary dolomite marine cements. Analysis of a variety of components within these reefs reveals significant variation in uranium isotope composition and trace metal chemistry between components, even within a single sample. Marine cements, which precipitated directly from seawater, have much lower contamination element concentrations (e.g. Al, Zr, Th) than depositional micrites, and appear to represent the best archive of ancient ocean conditions. These cements have high levels of Fe, Mn in shallow and deep reef facies (e.g. 2-3wt% Fe), but only Fe-oxide inclusions in peritidal settings. This distribution suggests ferruginous conditions under a surficial chemocline in this Neoproterozoic seawater. Uranium isotopes from pristine marine cements have relatively heavy values compared to modern seawater (median = -0.22 δ238U). These values are essentially unfractionated from riverine inputs, which we interpret as tracking extensive near quantitative low-T reduction of U(VI) to U(IV) by abundant soluble iron in seawater. Depositional components and late stage cements have a much lighter and more variable U isotope compositions (-0.71 to -0.08 δ238U). This work highlights the need for fundamental petrographic constraints on the preservation of depositional geochemical signatures in the future use and development of sedimentary redox proxies.

  14. Geochemical investigation of UMTRAP designated site at Grand Junction, Colorado

    International Nuclear Information System (INIS)

    Markos, G.; Bush, K.J.

    1983-09-01

    This report is the result of a geochemical investigation of the former uranium mill and tailings site at Grand Junction, Colorado. The objectives of the investigation are to characterize the geochemistry, to determine the contaminant distribution resulting from the former milling activities and tailings, and to infer chemical pathways and transport mechanisms from the contaminant distribution. The results should be used to model contaminant migration and to develop criteria for long-term containment media, such as a cover system which is impermeable to contaminant migration. This report assumes a familiarity with the hydrologic conditions of the site and the geochemical concepts underlying the investigation. The results reported are based on a sampling of waters in two seasons and solid material from the background, the area adjacent to the site, and the site. The solid samples were water extracted to remove easily soluble salts and acid extracted to remove carbonates and hydroxides. The water extracts and solid samples were analyzed for the major and trace elements. A limited number of samples were analyzed for radiological components. The report includes the methods of sampling, sample processing, analysis, and data interpretation. Four major conclusions are: (1) trace element concentrations in shallow subsurface waters adjacent to the tailings temporally vary up to an order of magnitude; (2) the riverbank soils and borehole waters are contaminated with uranium, radium, and trace elements from discharge of tailings solids and solutions during the active time of the mill; however, the movement of contaminants toward the Colorado River does not appear to be significant; (3) the Colorado River adjacent to the tailings is not contaminated; and (4) trace metals have accumulated at both the tailings/cover and tailings/soil interface because of precipitation reactions caused by chemical differences between the two materials

  15. The Physics of Heavy Oils: Implications for Recovery and Geophysical Monitoring

    Science.gov (United States)

    Schmitt, Douglas

    2007-03-01

    Our capacity to find and produce conventional light petroleum oils are unable to keep pace with the growth in the growing global demand for energy. With the breakpoint between petroleum production and consumption imminent, a good deal of recent efforts have focused on developing the `heavy' hydrocarbon reserves. Such resources include the extensive heavy oil deposits of Venezuela, the bitumen resources of Canada, and even the solid kerogens (oil shale) of the United States. Capital investments, in particular, have been large in Canada's oil sands due in part to the extensive nature of the resource and already in excess of 30% of Canada's production comes from heavier hydrocarbon deposits. The larger input costs associated with such projects, however, requires that the production be monitored more fully; and this necessitates that both the oils and the porous media which hold them be understood. Geophysical `time-lapse' monitoring seeks to better constrain the areal distribution and movements of fluids in the subsurface by examining the changes in a geophysical response such as seismic reflectivity, micro-gravity variations, or electrical conductivity that arise during production. For example, a changed geophysical seismic character directly depends on relies on variations in the longitudinal and transverse wave speeds and attenuation and mass densities of the materials in the earth. These are controlled by a number of extrinsic conditions such as temperature, fluid pressure, confining stress, and fluid phase and saturation state. Understanding the geophysical signature over a given reservoir requires that the behavior of the porous rock physical properties be well understood and a variety of measurements are being made in laboratories. In current practice, the interpretation of the geophysical field responses is assisted by combined modeling of fluid flow and seismic wave fields. The least understood link in this process, however, is the lack of knowledge on rock

  16. GEOCHEMICAL CONTROLS ON NUCLEAR MAGNETIC RESONANCE MEASUREMENTS

    International Nuclear Information System (INIS)

    Knight, Rosemary

    2008-01-01

    Proton nuclear magnetic resonance (NMR) is used in the Earth Sciences as a means of obtaining information about the molecular-scale environment of fluids in porous geological materials. Laboratory experiments were conducted to advance our fundamental understanding of the link between the NMR response and the geochemical properties of geological materials. In the first part of this research project, we studied the impact of both the surface-area-to-volume ratio (S/V) of the pore space and the surface relaxivity on the NMR response of fluids in sand-clay mixtures. This study highlighted the way in which these two parameters control our ability to use NMR measurements to detect and quantify fluid saturation in multiphase saturated systems. The second part of the project was designed to explore the way in which the mineralogic form of iron, as opposed to simply the concentration of iron, affects the surface relaxation rate and, more generally, the NMR response of porous materials. We found that the magnitude of the surface relaxation rate was different for the various iron-oxide minerals because of changes in both the surface-area-to-volume ratio of the pore space, and the surface relaxivity. Of particular significance from this study was the finding of an anomalously large surface relaxivity of magnetite compared to that of the other iron minerals. Differences in the NMR response of iron minerals were seen in column experiments during the reaction of ferrihydrite-coated quartz sand with aqueous Fe(II) solutions to form goethite, lepidocrocite and magnetite; indicating the potential use of NMR as a means of monitoring geochemical reactions. The final part of the research project investigated the impact of heterogeneity, at the pore-scale, on the NMR response. This work highlighted the way in which the geochemistry, by controlling the surface relaxivity, has a significant impact on the link between NMR data and the microgeometry of the pore space.

  17. Redesigning Curricula in Geology and Geophysics

    Science.gov (United States)

    Sparks, D. W.; Ewing, R. C.; Fowler, D.; Macik, M.; Marcantonio, F.; Miller, B.; Newman, J.; Olszewski, T.; Reece, R.; Rosser, S.

    2015-12-01

    In the summer of 2014, the Texas A&M Department of Geology and Geophysics partnered with the Texas A&M Center for Teaching Excellence to implement TAMU's curriculum revision process: a data-informed, faculty-driven, educational-developer-supported rebuilding of our degree programs and course offerings. The current curricula (B.S. and B.A. in Geology, B.S. in Geophysics) were put into place in 1997, following the merger of two separate departments. The needs and capabilities of the Department and the student body have changed significantly since that time: more than 50% turnover of the faculty, a rapidly-changing job climate for geologists and geophysicists, and a nearly five-fold increase in the undergraduate population to over 500 majors in Fall 2015. Surveys of former students, employers and faculty at other universities revealed more reasons to address the curriculum. Some of the most desired skills are also those at which our graduates feel and are perceived to be least prepared: oral communication and the ability to learn software packages (skills that are most challenging to teach with growing class sizes). The challenge facing the Department is to accommodate growing student numbers while maintaining strength in traditional instructor-intensive activities such as microscopy and field mapping, and also improving our graduates' non-geological skills (e.g., communication, software use, teamwork, problem-solving) to insulate them from volatility in the current job market. We formed the Curriculum Study Group, consisting of faculty, graduate students, advisors and curriculum experts, to gather and analyze data and define the knowledge and skill base a graduate of our department must have. In addition to conducting external surveys, this group interviewed current students and faculty to determine the strengths and weaknesses of our program. We developed program learning goals that were further specified into over fifty criteria. For each criteria we defined

  18. Report of the Cerro Chato ultrabasic geophysical studies

    International Nuclear Information System (INIS)

    Cicalese, H.; Mari, C.; Lema, F.; Valverde, C.; Haut, R.

    1987-01-01

    This report refers to the obtained results of geophysical practiced during the year 1985 in the area of the ultrabasic of Cerro Chato, located in the area called Puntas del Malbajar in Durazno province. The aim was rehearsed an answer of an ultrabasic behaviour of the geophysical prospecting methods.They were carried out studies in magnetometry, induced polarization, electromagnetism and resistivity measurements in electric vertical sound. As well conclusions as recommendations express that applied geophysical methods allow to make ultrabasic charts or maps.

  19. TEMPORAL VARIATIONS IN GEOPHYSICAL FIELDS AND EARTHQUAKE FORECASTING ISSUES

    Directory of Open Access Journals (Sweden)

    V. A. Parovyshny

    2015-01-01

    Full Text Available Results of the experimental long-term monitoring programme are presented. It is aimed at studying natural geophysical fields located above the gas deposit in the zone impacted by the active regional fault, and its objectives are to reveal how such fields are changing with time and to establish a relationship between the temporal changes and seismicity. According to the database it determines several typical indicators of variations in the geophysical fields, which take place only above the gas deposit. It is concluded that periods, when natural geophysical fields located above the gas deposit are unstable, are preceding the final phase of preparation of seismic events.

  20. Parts-based geophysical inversion with application to water flooding interface detection and geological facies detection

    Science.gov (United States)

    Zhang, Junwei

    data and prior distributions. We pose the geophysical inverse problem in terms of Gaussian random fields with mean functions controlled by petrophysical relationships and covariance functions controlled by a prior geological cross-section, including the definition of spatial boundaries for the geological facies. The petrophysical relationship problem is formulated as a regression problem upon each facies. The inversion is performed in a Bayesian framework. We demonstrate the usefulness of this strategy using a first synthetic case study, performing a joint inversion of gravity and galvanometric resistivity data with the stations all located at the ground surface. The joint inversion is used to recover the density and resistivity distributions of the subsurface. In a second step, we consider the possibility that the facies boundaries are deformable and their shapes are inverted as well. We use the level set approach to deform the facies boundaries preserving prior topological properties of the facies throughout the inversion. With the additional help of prior facies petrophysical relationships, topological characteristic of each facies, we make posterior inference about multiple geophysical tomograms based on their corresponding geophysical data misfits. The result of the inversion technique is encouraging when applied to a second synthetic case study, showing that we can recover the heterogeneities inside the facies, the mean values for the petrophysical properties, and, to some extent, the facies boundaries. A paper has been submitted to Geophysics on this topic and I am the first author of this paper. During this thesis, I also worked on the time lapse inversion problem of gravity data in collaboration with Marios Karaoulis and a paper was published in Geophysical Journal international on this topic. I also worked on the time-lapse inversion of cross-well geophysical data (seismic and resistivity) using both a structural approach named the cross-gradient approach and

  1. Isotopic and geochemical tracers in the evaluation of groundwater residence time and salinization problems at Santiago Island, Cape Verde

    Energy Technology Data Exchange (ETDEWEB)

    Carreira, Paula M.; Nunes, Dina [Quimica Analitica e Ambiental, IST/ITN, Universidade Tecnica de Lisboa, Estrada Nacional no. 10, 2686-953 Sacavem (Portugal); Marques, Jose M. [Centro de Petrologia e Geoquimica. Instituto Superior Tecnico, UTL, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Monteiro Santos, Fernando A. [Universidade de Lisboa-IDL, 1749-016 Lisboa (Portugal); Goncalves, Rui [Inst. Politecnico de Tomar, Quinta do Contador, Estrada da Serra, 2300 Tomar (Portugal); Pina, Antonio; Mota Gomes, Antonio [Instituto Superior de Educacao, Praia, Santiago (Cape Verde)

    2013-07-01

    Stable isotopes (δ{sup 18}O, δ{sup 2}H) and tritium ({sup 3}H), together with geochemistry and geophysical data, were used for evaluating groundwater recharge sources, flow paths, and residence times in a watershed on Santiago Island, Cape Verde, West Africa. Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. Low tritium concentrations at seven sampling sites indicate groundwater residence times greater than 50 years. Higher tritium values at other locations suggest more recent recharge. Young ages indicate local recharge and potential groundwater vulnerability to surface contamination and/or salt-water intrusion. Geochemical results indicate that water-rock interaction mechanisms are the major processes responsible for the groundwater quality (mainly calcium-bicarbonate type), reflecting the lithological composition of subsurface soil. (authors)

  2. Isotopic and geochemical tracers in the evaluation of groundwater residence time and salinization problems at Santiago Island, Cape Verde

    International Nuclear Information System (INIS)

    Carreira, Paula M.; Nunes, Dina; Marques, Jose M.; Monteiro Santos, Fernando A.; Goncalves, Rui; Pina, Antonio; Mota Gomes, Antonio

    2013-01-01

    Stable isotopes (δ 18 O, δ 2 H) and tritium ( 3 H), together with geochemistry and geophysical data, were used for evaluating groundwater recharge sources, flow paths, and residence times in a watershed on Santiago Island, Cape Verde, West Africa. Stable isotopes indicate the predominance of high-elevation precipitation that undergoes little evaporation prior to groundwater recharge. Low tritium concentrations at seven sampling sites indicate groundwater residence times greater than 50 years. Higher tritium values at other locations suggest more recent recharge. Young ages indicate local recharge and potential groundwater vulnerability to surface contamination and/or salt-water intrusion. Geochemical results indicate that water-rock interaction mechanisms are the major processes responsible for the groundwater quality (mainly calcium-bicarbonate type), reflecting the lithological composition of subsurface soil. (authors)

  3. Geochemical orientation for mineral exploration in the Hashemite Kingdom of Jordan

    Science.gov (United States)

    Overstreet, W.C.; Grimes, D.J.; Seitz, J.F.

    1982-01-01

    This report is a supplement to previous accounts of geochemical exploration conducted in the Hashemite Kingdom of Jordan by the Natural Resources Authority of the Royal Government of Jordan and the U.S. Geological Survey. The field work on which this report is based was sponsored by the U.S. Agency for International Development, U.S. Department of State. Procedures used in collecting various kinds of rocks, ores, slags, eluvial and alluvial sediments, heavy-mineral concentrates, and organic materials for use as geochemical sample media are summarized, as are the laboratory procedures followed for the analysis of these sample materials by semiquantitative spectrographic, atomic absorption, fluorometric, and X-ray diffraction methods. Geochemical evaluations of the possibilities for economic mineral deposits in certain areas are presented. The results of these preliminary investigations open concepts for further use in geochemical exploration in the search for metallic mineral deposits in Jordan. Perhaps the most desirable new activity would be hydrogeochemical exploration for uranium and base metals, accompanied by interpretation of such remote-sensing data as results of airborne radiometric surveys and computer-enhanced LANDSAT imagery. For more conventional approaches to geochemical exploration, however, several fundamental problems regarding proper choice of geochemical sample media for different geologic and geographic parts of the Country must be solved before effective surveys can be made. The present results also show that such common geochemical exploration techniques as the determination of the trace-element contents of soils, plant ash, and slags have direct application also toward the resolution of several archaeological problems in Jordan. These include the relation of trace-elements chemistry of local soils to the composition of botanic remains, the trace-elements composition of slags to the technological development of the extractive metallurgy of

  4. A Geochemical Reaction Model for Titration of Contaminated Soil and Groundwater at the Oak Ridge Reservation

    Science.gov (United States)

    Zhang, F.; Parker, J. C.; Gu, B.; Luo, W.; Brooks, S. C.; Spalding, B. P.; Jardine, P. M.; Watson, D. B.

    2007-12-01

    This study investigates geochemical reactions during titration of contaminated soil and groundwater at the Oak Ridge Reservation in eastern Tennessee. The soils and groundwater exhibits low pH and high concentrations of aluminum, calcium, magnesium, manganese, various trace metals such as nickel and cobalt, and radionuclides such as uranium and technetium. The mobility of many of the contaminant species diminishes with increasing pH. However, base additions to increase pH are strongly buffered by various precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior and associated geochemical effects is thus critical to evaluate remediation performance of pH manipulation strategies. This study was undertaken to develop a practical but generally applicable geochemical model to predict aqueous and solid-phase speciation during soil and groundwater titration. To model titration in the presence of aquifer solids, an approach proposed by Spalding and Spalding (2001) was utilized, which treats aquifer solids as a polyprotic acid. Previous studies have shown that Fe and Al-oxyhydroxides strongly sorb dissolved Ni, U and Tc species. In this study, since the total Fe concentration is much smaller than that of Al, only ion exchange reactions associated with Al hydroxides are considered. An equilibrium reaction model that includes aqueous complexation, precipitation, ion exchange, and soil buffering reactions was developed and implemented in the code HydroGeoChem 5.0 (HGC5). Comparison of model results with experimental titration curves for contaminated groundwater alone and for soil- water systems indicated close agreement. This study is expected to facilitate field-scale modeling of geochemical processes under conditions with highly variable pH to develop practical methods to control contaminant mobility at geochemically complex sites.

  5. An overview of the geochemical code MINTEQ: Applications to performance assessment for low-level wastes

    International Nuclear Information System (INIS)

    Peterson, S.R.; Opitz, B.E.; Graham, M.J.; Eary, L.E.

    1987-03-01

    The MINTEQ geochemical computer code, developed at the Pacific Northwest Laboratory (PNL), integrates many of the capabilities of its two immediate predecessors, MINEQL and WATEQ3. The MINTEQ code will be used in the Special Waste Form Lysimeters-Arid program to perform the calculations necessary to simulate (model) the contact of low-level waste solutions with heterogeneous sediments of the interaction of ground water with solidified low-level wastes. The code can calculate ion speciation/solubilitya, adsorption, oxidation-reduction, gas phase equilibria, and precipitation/dissolution of solid phases. Under the Special Waste Form Lysimeters-Arid program, the composition of effluents (leachates) from column and batch experiments, using laboratory-scale waste forms, will be used to develop a geochemical model of the interaction of ground water with commercial, solidified low-level wastes. The wastes being evaluated include power-reactor waste streams that have been solidified in cement, vinyl ester-styrene, and bitumen. The thermodynamic database for the code was upgraded preparatory to performing the geochemical modeling. Thermodynamic data for solid phases and aqueous species containing Sb, Ce, Cs, or Co were added to the MINTEQ database. The need to add these data was identified from the characterization of the waste streams. The geochemical model developed from the laboratory data will then be applied to predict the release from a field-lysimeter facility that contains full-scale waste samples. The contaminant concentrations migrating from the waste forms predicted using MINTEQ will be compared to the long-term lysimeter data. This comparison will constitute a partial field validation of the geochemical model

  6. Geological, Geophysical, And Thermal Characteristics Of The Salton Sea Geothermal Field, California

    Energy Technology Data Exchange (ETDEWEB)

    Younker, L.W.; Kasameyer, P. W.; Tewhey, J. D.

    1981-01-01

    The Salton Sea Geothermal Field is the largest water-dominated geothermal field in the Salton Trough in Southern California. Within the trough, local zones of extension among active right-stepping right-lateral strike-slip faults allow mantle-derived magmas to intrude the sedimentary sequence. The intrusions serves as heat sources to drive hydrothermal systems. We can characterize the field in detail because we have an extensive geological and geophysical data base. The sediments are relatively undeformed and can be divided into three categories as a function of depth: (1) low-permeability cap rock, (2) upper reservoir rocks consisting of sandstones, siltstones, and shales that were subject to minor alterations, and (3) lower reservoir rocks that were extensively altered. Because of the alteration, intergranular porosity and permeability are reduced with depth. permeability is enhanced by renewable fractures, i.e., fractures that can be reactivated by faulting or natural hydraulic fracturing subsequent to being sealed by mineral deposition. In the central portion of the field, temperature gradients are high near the surface and lower below 700 m. Surface gradients in this elliptically shaped region are fairly constant and define a thermal cap, which does not necessarily correspond to the lithologic cap. At the margin of the field, a narrow transition region, with a low near-surface gradient and an increasing gradient at greater depths, separates the high temperature resource from areas of normal regional gradient. Geophysical and geochemical evidence suggest that vertical convective motion in the reservoir beneath the thermal cap is confined to small units, and small-scale convection is superimposed on large-scale lateral flow of pore fluid. Interpretation of magnetic, resistivity, and gravity anomalies help to establish the relationship between the inferred heat source, the hydrothermal system, and the observed alteration patterns. A simple hydrothermal model is

  7. Geophysical phenomena classification by artificial neural networks

    Science.gov (United States)

    Gough, M. P.; Bruckner, J. R.

    1995-01-01

    Space science information systems involve accessing vast data bases. There is a need for an automatic process by which properties of the whole data set can be assimilated and presented to the user. Where data are in the form of spectrograms, phenomena can be detected by pattern recognition techniques. Presented are the first results obtained by applying unsupervised Artificial Neural Networks (ANN's) to the classification of magnetospheric wave spectra. The networks used here were a simple unsupervised Hamming network run on a PC and a more sophisticated CALM network run on a Sparc workstation. The ANN's were compared in their geophysical data recognition performance. CALM networks offer such qualities as fast learning, superiority in generalizing, the ability to continuously adapt to changes in the pattern set, and the possibility to modularize the network to allow the inter-relation between phenomena and data sets. This work is the first step toward an information system interface being developed at Sussex, the Whole Information System Expert (WISE). Phenomena in the data are automatically identified and provided to the user in the form of a data occurrence morphology, the Whole Information System Data Occurrence Morphology (WISDOM), along with relationships to other parameters and phenomena.

  8. Geophysical constraints on Washington convergent margin structure

    Science.gov (United States)

    Finn, C.

    1990-01-01

    Gravity and magnetic maps of western Washington reveal the lateral structure and fabric of the Washington Coast Range, Puget Basin, and southern Washington Cascade Range. Two-dimensional gravity and magnetic modeling constrained with geological and other geophysical data indicate that the Coast Range Province rocks are about 1 km thick at the coast, thickening to as much as 30 km near their postulated eastern edge. A composition largely of basalt and gabbro with little interbedded sediments is suggested. Under these rocks may be mantle or a subduction complex composed of dense mafic, ultramafic, and sedimentary rocks like that proposed to underlie Vancouver Island. The Washington model requires that the proposed subduction complex be more dense than the trench sediments and, therefore, that material denser than sediments be incorporated within it. The absence of continental mantle and the modeled wedge shape of the Coast Range Province upper crust suggest that erosion of the bottom of the overriding plate by subduction processes may have occurred. -from Author

  9. Geophysical Surveys Over a Terminal Moraine

    Science.gov (United States)

    Bentley, L. R.; Langston, G.; Hayashi, M.

    2007-12-01

    Alpine watersheds represent the headwaters of many major rivers in western Canada. Consequently, understanding the hydrological cycle within these watersheds is critical for modeling the effects of climate change on water resources in western Canada and for developing informed water management strategies. Terminal moraines represent a significant hydrological response unit within many alpine watersheds in western Canada. Recent studies suggest that these features may provide sites for water storage. The preliminary results of a geophysical survey of a terminal moraine exhibiting geomorphological characteristics suggesting an ice-core will be presented. It is hypothesized that bedrock topography and the presence of ice creates barriers and channels groudwater flow. The focus of the survey was to delineate the hydrologically significant features within the moraine using electrical resistivity imaging (ERI), seismic refraction, and ground penetrating radar (GPR). Buried ice was easily detected using ERI due to high resistivity of over 1 MOhm-m. However, it was not as extensive as expected. Seismic refraction proved to be most useful in detecting the underlying bedrock. GPR images showed many reflection fragments but were noisy and difficult to interpret. Regions of relatively high electrical conductivity suggest some degree of channelization of groundwater in the vicinity of a tarn.

  10. Geophysical exploration of the Kalahari Suture Zone

    Science.gov (United States)

    Brett, J. S.; Mason, R.; Smith, P. H.

    2000-04-01

    Fancamp Resources Limited of Montreal, Canada, commenced exploration of the Kalahari Suture Zone in southwest Botswana in 1996, following the interpretation of airborne magnetic surveys covering 400 km of strike along the Kalahari Suture Zone. Initial focus was on mafic/ultramafic intrusions associated with the Tshane Complex as potential targets for CuNiPGM mineralization, but these targets are now considered to be too deeply buried (> 700 m) to be of economic significance at this time. The exploration focus has been redirected to several prospective large coincident magnetic/gravity anomalies. These are considered prospective targets for Olympic Dam-type CuCo mineralisation associated with alkaline intrusive complexes, and/or NiCuCoPGM mineralisation associated with basic intrusive complexes. The two most important and prospective targets are the so-called 'Great Red Spot' and Tsetseng Complex. Additional ground geophysical surveys and deep drilling are planned for the next phase of exploration. These large targets are of high priority and represent tremendous potential for mineral development in the sparsely populated area of western Botswana.

  11. Novel geophysical ground monitoring of SAGD effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Gharibi, Mehran [Quantec Geoscience Limited (Canada)

    2011-07-01

    This paper presents a novel geophysical ground monitoring of SAGD effectiveness. First, a brief introduction to the resistivity method is given, followed by a presentation of Quantec's current Titan 3D technology with its customizable array configuration allowing true 3D sampling of the subsurface. The Titan 3D system as configured for this survey produced well over 100,000 data samples. This resolution is not achievable with traditional survey methodology. A 3D resistivity survey can be used to detect the fluid (water/oil) displacement within a reservoir that can be caused by SAGD extraction/injection in an active oil field. A 3D survey is conducted and establishes a reference time (zero-time) of the subsurface resistivity distribution. A repeated 3D survey over the same area then produces a late time (time-lapse) snap-shot of the subsurface resistivity and the percentage difference map is calculated using two-different time-lapse images. Lateral resolutions are found to be accurate while vertical resolution weakens with depth. The percentage difference technique is very robust against the noise in the measurements.

  12. Satellite gravity gradient grids for geophysics.

    Science.gov (United States)

    Bouman, Johannes; Ebbing, Jörg; Fuchs, Martin; Sebera, Josef; Lieb, Verena; Szwillus, Wolfgang; Haagmans, Roger; Novak, Pavel

    2016-02-11

    The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite aimed at determining the Earth's mean gravity field. GOCE delivered gravity gradients containing directional information, which are complicated to use because of their error characteristics and because they are given in a rotating instrument frame indirectly related to the Earth. We compute gravity gradients in grids at 225 km and 255 km altitude above the reference ellipsoid corresponding to the GOCE nominal and lower orbit phases respectively, and find that the grids may contain additional high-frequency content compared with GOCE-based global models. We discuss the gradient sensitivity for crustal depth slices using a 3D lithospheric model of the North-East Atlantic region, which shows that the depth sensitivity differs from gradient to gradient. In addition, the relative signal power for the individual gradient component changes comparing the 225 km and 255 km grids, implying that using all components at different heights reduces parameter uncertainties in geophysical modelling. Furthermore, since gravity gradients contain complementary information to gravity, we foresee the use of the grids in a wide range of applications from lithospheric modelling to studies on dynamic topography, and glacial isostatic adjustment, to bedrock geometry determination under ice sheets.

  13. Fluctuations and Response in Geophysical Fluid Dynamics

    Science.gov (United States)

    Lucarini, Valerio

    The climate is a complex, chaotic, non-equilibrium system featuring a limited horizon of predictability, variability on a vast range of temporal and spatial scales, instabilities resulting into energy transformations, and mixing and dissipative processes resulting into entropy production. Despite great progresses, we still do not have a complete theory of climate dynamics able to account for instabilities, equilibration processes, response to changing parameters of the system, and multiscale effects. We will outline some possible applications of the response theory developed by Ruelle for non-equilibrium statistical mechanical systems, showing how it allows for setting on firm ground and on a coherent framework concepts like climate sensitivity, climate response, and climate tipping points, and to construct parametrizations for unresolved processes. We will show results for comprehensive global climate models. The results are promising in terms of suggesting new ways for approaching the problem of climate change prediction and for using more efficiently the enormous amounts of data produced by modeling groups around the world. Ref: V. Lucarini, R. Blender, C. Herbert, F. Ragone, S. Pascale, J. Wouters, Mathematical and Physical Ideas for Climate Science, Reviews of Geophysics 52, 809-859 (2014)

  14. Mineralogical and Geochemical Analysis of Howardite DaG 779: understanding geological evolution of asteroid (4) Vesta

    Science.gov (United States)

    Marcel Müller, Christian; Mengel, Kurt; Singh Thangjam, Guneshwar; Weckwerth, Gerd

    2016-04-01

    metasomatic reactions were observed between clinopyroxene (pigeonite) and a sulphide-bearing agent, according to the principal reaction Pigeonite (Fe-rich) + S2 ↔ FeS + Augit (Mg-rich) + SiO2. This type of metasomatism (Zhang et al. (2013)) is not well understood yet. References: Grossman, J. N. (2000): The Meteoritical Bulletin, No. 84, 2000 August. Meteoritics & Planetary Science, 35: A119-A225. doi: 10.1111/j.1945-5100.2000.tb01797.x. Toplis, M.J. et al. (2013): Chondritic models of 4 Vesta: Implications for geochemical and geophysical properties. Meteoritics & Planetary Science, 48: 2300-2315. doi: 10.1111/maps.12195. Zhang, A. et al. (2013): Record of S-rich vapors on asteroid 4 Vesta: Sulfurization in the Northwest Africa 2339 eucrite. Geochim. Cosmochim. Acta 109, 1-13. Mittlefehldt, D.W., (2015): Asteroid (4) Vesta: I. The howardite-eucrite-diogenite (HED) clan of meteorites. Chemie Erde-Geochem. 75, 2, 155-183. Prettyman, T.H. et al. (2013): Neutron absorption constraints on the composition of 4 Vesta. Meteoritics & Planetary Science 48:2211-2236.

  15. Unified Geophysical Cloud Platform (UGCP) for Seismic Monitoring and other Geophysical Applications.

    Science.gov (United States)

    Synytsky, R.; Starovoit, Y. O.; Henadiy, S.; Lobzakov, V.; Kolesnikov, L.

    2016-12-01

    We present Unified Geophysical Cloud Platform (UGCP) or UniGeoCloud as an innovative approach for geophysical data processing in the Cloud environment with the ability to run any type of data processing software in isolated environment within the single Cloud platform. We've developed a simple and quick method of several open-source widely known software seismic packages (SeisComp3, Earthworm, Geotool, MSNoise) installation which does not require knowledge of system administration, configuration, OS compatibility issues etc. and other often annoying details preventing time wasting for system configuration work. Installation process is simplified as "mouse click" on selected software package from the Cloud market place. The main objective of the developed capability was the software tools conception with which users are able to design and install quickly their own highly reliable and highly available virtual IT-infrastructure for the organization of seismic (and in future other geophysical) data processing for either research or monitoring purposes. These tools provide access to any seismic station data available in open IP configuration from the different networks affiliated with different Institutions and Organizations. It allows also setting up your own network as you desire by selecting either regionally deployed stations or the worldwide global network based on stations selection form the global map. The processing software and products and research results could be easily monitored from everywhere using variety of user's devices form desk top computers to IT gadgets. Currents efforts of the development team are directed to achieve Scalability, Reliability and Sustainability (SRS) of proposed solutions allowing any user to run their applications with the confidence of no data loss and no failure of the monitoring or research software components. The system is suitable for quick rollout of NDC-in-Box software package developed for State Signatories and aimed for

  16. The University of Texas Institute for Geophysics Marine Geology and Geophysics Field Course

    Science.gov (United States)

    Duncan, D.; Davis, M. B.; Goff, J. A.; Gulick, S. P. S.; McIntosh, K. D.; Saustrup, S., Sr.

    2014-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers a three-week marine geology and geophysics field course during the spring-summer intersession. The course provides hands-on instruction and training for graduate and upper-level undergraduate students in high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples. Students participate in an initial three days of classroom instruction designed to communicate geological context of the field area along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. Our field sites at Port Aransas, and Galveston, TX, and Grand Isle, LA, provide ideal locations for students to investigate coastal processes of the Gulf Coast and continental shelf through application of geophysical techniques in an exploratory mode. At sea, students assist with survey design and instrumentation set up while learning about acquisition parameters, data quality control, trouble-shooting, and safe instrument deployment and retrieval. In teams of four, students work in onshore field labs preparing sediment samples for particle size analysis and data processing. During the course's final week, teams return to the classroom where they integrate, interpret, and visualize data in a final project using industry-standard software such as Echos, Landmark, Caris, and Fledermaus. The course concludes with a series of final presentations and discussions in which students examine geologic history and/or sedimentary processes represented by the Gulf Coast continental shelf with academic and industry supporters. Students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and low instructor to student ratio (sixteen

  17. Geology, geochemistry, and geophysics of the Moon: Status of current understanding

    Science.gov (United States)

    Jaumann, R.; Hiesinger, H.; Anand, M.; Crawford, I. A.; Wagner, R.; Sohl, F.; Jolliff, B. L.; Scholten, F.; Knapmeyer, M.; Hoffmann, H.; Hussmann, H.; Grott, M.; Hempel, S.; Köhler, U.; Krohn, K.; Schmitz, N.; Carpenter, J.; Wieczorek, M.; Spohn, T.; Robinson, M. S.; Oberst, J.

    2012-12-01

    The Moon is key to understanding both Earth and our Solar System in terms of planetary processes and has been a witness of the Solar System history for more than 4.5 Ga. Building on earlier telescopic observations, our knowledge about the Moon was transformed by the wealth of information provided by Apollo and other space missions. These demonstrated the value of the Moon for understanding the fundamental processes that drive planetary formation and evolution. The Moon was understood as an inert body with its geology mainly restricted to impact and volcanism with associated tectonics, and a relative simple composition. Unlike Earth, an absence of plate tectonics has preserved a well-defined accretion and geological evolution record. However recent missions to the Moon show that this traditional view of the lunar surface is certainly an over simplification. For example, although it has long been suspected that ice might be preserved in cold traps at the lunar poles, recent results also indicate the formation and retention of OH- and H2O outside of polar regions. These volatiles are likely to be formed as a result of hydration processes operating at the lunar surface including the production of H2O and OH by solar wind protons interacting with oxygen-rich rock surfaces produced during micrometeorite impact on lunar soil particles. Moreover, on the basis of Lunar Prospector gamma-ray data, the lunar crust and underlying mantle has been found to be divided into distinct terranes that possess unique geochemical, geophysical, and geological characteristics. The concentration of heat producing elements on the nearside hemisphere of the Moon in the Procellarum KREEP Terrane has apparently led to the nearside being more volcanically active than the farside. Recent dating of basalts has shown that lunar volcanism was active for almost 3 Ga, starting at about 3.9-4.0 Ga and ceasing at ˜1.2 Ga. A recent re-processing of the seismic data supports the presence of a partially

  18. Applied Geophysics in the world of tomorrow - Microfabrication arrives

    Science.gov (United States)

    Johnson, R. M.

    2012-12-01

    Instrument manufacturers have a unique perspective on the design and use of geophysical equipment. The field instrument must provide reliable and repeatable performance in every climate condition and environmental extreme. The gear must be easy to use and more importantly easy to understand for non-native English speakers. I have traveled the world installing, repairing, commissioning and demonstrating geophysical survey systems. Everywhere I have traveled there is one unassailable fact - our geophysicist compatriots in developed and developing countries are hungry for information and hungry for technology. They want more and better systems to help improve their understanding of the subsurface. And they want to serve their countries by helping to exploit natural resources. I hold up for your review the first highly successful portable magnetometer, the G-856. Designed in 1981 with over 5000 sold, it is still produced in record numbers today for use all over the world. How could it be that a rather simple device could be so long lived, and make such an impact in exploration programs for 32 years? The answer is in producing reliable and easy to use equipment that is affordable. One might compare it to the iPad or Android device of today. The innovative and no-frills interface has attracted users from all markets including mining, oil/gas, archaeology, environmental, UXO/military and forensics. Powerful ancillary software to process the data has always been included at no charge, offering geoscientists a solution rather than a black box. Many of our technologies are poised for dramatic breakthroughs in miniaturization and interconnectivity. I point specifically to the micro-fabrication of the cesium vapor magnetometer. Initiated 5 years ago in conjunction with NIST, Geometrics has embarked on a high stakes game of minimizing size, weight, power consumption and price while eliminating dead zones and maintaining or increasing sensitivity and sample speed. These new

  19. Geophysical Surveys in Archaeology: Guidance for Surveyors and Sponsors

    National Research Council Canada - National Science Library

    Somers, Lewis

    2003-01-01

    The last few years have seen a significant increase in the use of geophysical techniques by archaeologists in the United States working in both academic settings and Cultural Resources Management (CRM). Since 1995...

  20. The influence of geophysical processes on the Earth's rotation

    International Nuclear Information System (INIS)

    Nastula, J.

    1985-01-01

    The problem of the influence of geophysical processes on the Earth's rotation is presented. The role of these processes in the variations of the length of day is described in this part. 27 refs., 19 figs. (author)

  1. Astronaut-Deployable Geophysical and Environmental Monitoring Stations

    Science.gov (United States)

    Guzewich, S. D.; Bleacher, J. E.; Smith, M. D.; Khayat, A.; Conrad, P.

    2017-02-01

    Geophysical and environmental monitoring stations could be deployed by astronauts exploring Mars, the Moon, or asteroids, and create a broad network that would collect high-value scientific information while also enhancing astronaut safety.

  2. Airborne Geophysical/Geological Mineral Inventory CIP Program

    National Research Council Canada - National Science Library

    1999-01-01

    The Airborne-Geophysical/Geological Mineral Inventory project is a special multi-year investment to expand the knowledge base of Alaska's mineral resources and catalyze private-sector mineral development...

  3. Solar Geophysical Data (SGD) Reports (1955-2009)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Solar-Geophysical Data (SGD) reports were a comprehensive compilation of many different kinds of observational data of the sun's activity and its effects on the...

  4. Geophysical applications for arctic/subarctic transportation planning.

    Science.gov (United States)

    2014-07-01

    This report describes a series of geophysical surveys conducted in conjunction with : geotechnical investigations carried out by the Alaska Department of Transportation and Public : Facilities. The purpose of the study was to evaluate the value of an...

  5. Comparison study of selected Geophysical and geotechnical parameters

    DEFF Research Database (Denmark)

    Nissen, Randi Warncke; Poulsen, Søren Erbs

    Successful foundation of constructions relies on accurate characterization of the geotechnical properties of the subsurface. By implementing data from geophysical surveys, the placement of geotechnical drillings can be significantly improved, potentially reducing the number of required drillings....

  6. The McDonnell Douglas geophysical observatory program progress report 13 Conjugate point riometer program

    Science.gov (United States)

    Baker, M. B.

    1975-01-01

    This report, the thirteenth and final progress report on the McDonnell Douglas Geophysical Observatory Program, discusses history of the program from 1962 through 1973, and results of the research carried out in 1974. Topic areas covered include: Station operation; Ionospheric work; Solar studies, Magnetospheric studies; Satellite measurements; International participation; and, 1974 research on solar activity, ATS-6 studies, magnetospheric physics, and station operation.

  7. The application of evidential belief function in the integration of regional geochemical and geological data over the Ife-Ilesha goldfield, Nigeria

    Science.gov (United States)

    Likkason, Othniel K.; Shemang, Elisha M.; Suh, Cheo E.

    1997-10-01

    There are several methods available for the integration of geological, geophysical and even remotely sensed data sets. Several published reports have discussed the successful application of these integration techniques, including geologically orientated geographical information systems (GIS), to non-renewable resource exploration. Many geoscience data sets often have only partial coverage, and in most cases have different spatial resolution. These shortcomings plague statistical integration schemes employed in resource evaluation. In this paper, the evidential belief function approach is examined and applied to the integration of geological and geochemical data sets over the Ife-Ilesha goldfield, southwest Nigeria. In using this approach, nine maps of trace element concentrations (whole rock) and that of the bedrock geology of the test area were digitised. The characteristic grid values of the digitised maps were converted to degrees of belief, with a Au bearing mineral deposit as the target proposition. These resulting spatial data sets were pooled using the Dempster-Shafer combination rule. The resulting maps define portions of the study area with known auriferous mineral occurrences and even outline areas of past mining operations. There are additional areas with high interest that are not linked with known mineralisation and could therefore represent viable exploration targets. The Dempster-Shafer method of evidential reasoning appears to be suitable in identifying areas of known Au mineralisation in the test area. One of the major difficulties of this method is that the evidential belief function depends on the exploration target, which can only be defined, at present, by the interpreter's intuitive and qualitative knowledge of the environmental proposition being explored.

  8. Geophysical well-log measurements in three drill holes at Salt Valley, Utah

    International Nuclear Information System (INIS)

    Daniels, J.J.; Hite, R.J.; Scott, J.H.

    1980-01-01

    Three exploratory drill holes were drilled at Salt Valley, Utah, to study the geologic, physical, geochemical, and hydrologic properties of the evaporite sequence in the Permian Paradox Member of the Hermosa Formation. The results of these studies will be used to help to determine the suitability of salt deposits in the Paradox basin as a storage medium for radioactive waste material. The following geophysical well-log measurements were made in each of the three drill holes: (1) density, (2) neutron, (3) acoustic velocity, (4) normal resistivity, and (5) gamma ray. Widely spaced resistivity and conductivity well-log measurements were made in the deep drill hole. Each of these well-log measurements shows the division of the evaporite sequence into halite and interbed sections. At the present time the most useful well-logging measurements for determining the individual lithologies in an evaporite sequence are gamma ray, neutron, density, and acoustic velocity. The high resistivity contrast between the drilling fluid (0.5 ohm-m) and salt (10,000 ohm-m) makes it difficult to obtain quantitative measurements of electrical properties in an evaporite sequence. Tests of widely spaced electrode configurations show that the effects of the brine on the resistivity measurements can be reduced, and the depth of investigation increased, by increasing the source-receiver electrode spacing. Tests of a single-coil induction probe show good resolution of the contrasting electrical properties of the various interbed lithologies

  9. Segmentation of complex geophysical structures with well data

    OpenAIRE

    Gout , Christian; Le Guyader , Carole

    2006-01-01

    International audience; In many problems of geophysical interest, when trying to segment images (i.e., to locate interfaces between different regions on the images), one has to deal with data that exhibit very complex structures. This occurs, for instance, when describing complex geophysical images (with layers, faults,...); in that case, segmentation is very difficult. Moreover, the segmentation process requires to take into account well data to interpolate, which implies integrating interpo...

  10. Synchronization of Well Log Data and Geophysical Data with Remote Sensing Technique to Develop the Hydrocarbon System of Bengal Basin

    Science.gov (United States)

    Kesh, S.; Samadder, P. K.

    2012-12-01

    Remote sensing along with more conventional exploration techniques such as geophysics and reconnaissance field mapping can help to establish regional geologic relationships, to extract major structural features and to pinpoint anomalous patterns. Many well have been drilled in Bengal basin still no commercially viable reserves have been discovered. Geophysical well logging is used in virtually every oil well. It is the primary means by which we characterize the subsurface in search of hydrocarbons. Oil and gas exploration activities for large areas require ground gravity surveys to facilitate detailed geological interpretations for subsurface features integrating geological cross-sections with the sub-surface structural trends leads to the identification of prospect areas. Remote sensing, geological and geophysical data integration provide accurate geometric shapes of the basins. Bengal basin has a sedimentary fill of 10-15 km, is the northernmost of the east coast basins of India In the first phase Remote sensing satellite sensors help in identifying surface anomaly which indicates the presence of hydrocarbon reservoirs providing regional geological settings of petroleferous basins. It provides accurate and visual data for directly determining geometric shapes of basin. It assists in the selection of exploration regions by defining the existence of sedimentary basin. Remote sensing methods can generate a wealth of information useful in determining the value of exploratory prospecting. In the second phase Well Log data provide relative subsurface information for oil and gas exploration. Remote sensing data are merged with other available information such as Aeromagnetic, gravity, geochemical surveys and 2D seismic surveys. The result of this phase is to estimate the outcome of oil discovery probabilities for locating oil prospects

  11. Near real-time imaging of molasses injections using time-lapse electrical geophysics at the Brandywine DRMO, Brandywine, Maryland

    Science.gov (United States)

    Versteeg, R. J.; Johnson, T.; Major, B.; Day-Lewis, F. D.; Lane, J. W.

    2010-12-01

    Enhanced bioremediation, which involves introduction of amendments to promote biodegradation, increasingly is used to accelerate cleanup of recalcitrant compounds and has been identified as the preferred remedial treatment at many contaminated sites. Although blind introduction of amendments can lead to sub-optimal or ineffective remediation, the distribution of amendment throughout the treatment zone is difficult to measure using conventional sampling. Because amendments and their degradation products commonly have electrical properties that differ from those of ambient soil, time-lapse electrical geophysical monitoring has the potential to verify amendment emplacement and distribution. In order for geophysical monitoring to be useful, however, results of the injection ideally should be accessible in near real time. In August 2010, we demonstrated the feasibility of near real-time, autonomous electrical geophysical monitoring of amendment injections at the former Defense Reutilization and Marketing Office (DRMO) in Brandywine, Maryland. Two injections of about 1000 gallons each of molasses, a widely used amendment for enhanced bioremediation, were monitored using measurements taken with borehole and surface electrodes. During the injections, multi-channel resistance data were recorded; data were transmitted to a server and processed using a parallel resistivity inversion code; and results in the form of time-lapse imagery subsequently were posted to a website. This process occurred automatically without human intervention. The resulting time-lapse imagery clearly showed the evolution of the molasses plume. The delay between measurements and online delivery of images was between 45 and 60 minutes, thus providing actionable information that could support decisions about field procedures and a check on whether amendment reached target zones. This experiment demonstrates the feasibility of using electrical imaging as a monitoring tool both during amendment emplacement

  12. Geophysics Under Pressure: Large-Volume Presses Versus the Diamond-Anvil Cell

    Science.gov (United States)

    Hazen, R. M.

    2002-05-01

    Prior to 1970, the legacy of Harvard physicist Percy Bridgman dominated high-pressure geophysics. Massive presses with large-volume devices, including piston-cylinder, opposed-anvil, and multi-anvil configurations, were widely used in both science and industry to achieve a range of crustal and upper mantle temperatures and pressures. George Kennedy of UCLA was a particularly influential advocate of large-volume apparatus for geophysical research prior to his death in 1980. The high-pressure scene began to change in 1959 with the invention of the diamond-anvil cell, which was designed simultaneously and independently by John Jamieson at the University of Chicago and Alvin Van Valkenburg at the National Bureau of Standards in Washington, DC. The compact, inexpensive diamond cell achieved record static pressures and had the advantage of optical access to the high-pressure environment. Nevertheless, members of the geophysical community, who favored the substantial sample volumes, geothermally relevant temperature range, and satisfying bulk of large-volume presses, initially viewed the diamond cell with indifference or even contempt. Several factors led to a gradual shift in emphasis from large-volume presses to diamond-anvil cells in geophysical research during the 1960s and 1970s. These factors include (1) their relatively low cost at time of fiscal restraint, (2) Alvin Van Valkenburg's new position as a Program Director at the National Science Foundation in 1964 (when George Kennedy's proposal for a Nation High-Pressure Laboratory was rejected), (3) the development of lasers and micro-analytical spectroscopic techniques suitable for analyzing samples in a diamond cell, and (4) the attainment of record pressures (e.g., 100 GPa in 1975 by Mao and Bell at the Geophysical Laboratory). Today, a more balanced collaborative approach has been adopted by the geophysics and mineral physics community. Many high-pressure laboratories operate a new generation of less expensive

  13. Geostatistical regularization operators for geophysical inverse problems on irregular meshes

    Science.gov (United States)

    Jordi, C.; Doetsch, J.; Günther, T.; Schmelzbach, C.; Robertsson, J. OA

    2018-05-01

    Irregular meshes allow to include complicated subsurface structures into geophysical modelling and inverse problems. The non-uniqueness of these inverse problems requires appropriate regularization that can incorporate a priori information. However, defining regularization operators for irregular discretizations is not trivial. Different schemes for calculating smoothness operators on irregular meshes have been proposed. In contrast to classical regularization constraints that are only defined using the nearest neighbours of a cell, geostatistical operators include a larger neighbourhood around a particular cell. A correlation model defines the extent of the neighbourhood and allows to incorporate information about geological structures. We propose an approach to calculate geostatistical operators for inverse problems on irregular meshes by eigendecomposition of a covariance matrix that contains the a priori geological information. Using our approach, the calculation of the operator matrix becomes tractable for 3-D inverse problems on irregular meshes. We tested the performance of the geostatistical regularization operators and compared them against the results of anisotropic smoothing in inversions of 2-D surface synthetic electrical resistivity tomography (ERT) data as well as in the inversion of a realistic 3-D cross-well synthetic ERT scenario. The inversions of 2-D ERT and seismic traveltime field data with geostatistical regularization provide results that are in good accordance with the expected geology and thus facilitate their interpretation. In particular, for layered structures the geostatistical regularization provides geologically more plausible results compared to the anisotropic smoothness constraints.

  14. A Geophysical Investigation at Potrillo Maar

    Science.gov (United States)

    Moncada Gutierrez, Manuel

    The Potrillo Volcanic Field (PVF) is a unique geological site located in Dona Ana County the southernmost part of New Mexico, and part of northern part of Chihuahua, Mexico. The main feature of the southern PVF is Potrillo Maar. This maar-volcano straddles the international boundary between United States and Mexico and lies within the southern part of the Rio Grande Rift. The Potrillo Maar was formed about 20,000 years ago in three major events that formed basalt lava flows and ejecta deposits that consist of crustal and mantle xenoliths. The purpose of this thesis is to determine the area of the maar-diatreme, the severely fractured rock created by the explosion where the crater was made, and to estimate the thickness of its basalt layers using gravity, magnetics, and resistivity tomography surveys. These Potential field methods also provided a better understanding of the shallower structures of the near diatreme. All the geophysical data was analyzed using the GM-SYS software package in order to create 2D cross section models to differentiate the diatreme, basalts and surrounding structures. Forward modeling has revealed a complex subsurface maar structure. Modeling of 2-D cross-sections requires bodies with very low negative susceptibilities adequately match observations and error. These negative susceptibilities suggest that part of this diatreme composed of pre-maar volcanic that are older than the latest geomagnetic reversal. The diatreme has a depth of 125 m in the deepest part of the sections. A basaltic feeder dike for the Potrillo maar was also imaged. The main dike is located in the center of the crater where three scoria cones are exposed at the surface. Other smaller dikes are located within the diatreme.

  15. Uruguay mining inventory. Geochemical prospecting results of the Las Flores aerial map

    International Nuclear Information System (INIS)

    Zeegers, H.; Bonnefoy, D.; Garau, M.; Spangenberg, J.

    1981-01-01

    In the context of the Uruguay mining inventory, the aerial photography map Las Flores had been covered by a specific strategic which included geochemical prospecting elements. The surface covered has the 550 km2, and 1042 samples which they have been analized in Orleans France. 22 elements by plasma spectroscopy and gold by atomic absorption and for uranium laser spectroscopy . They have been evidenced the following anomalies: gold, Pb, Pb-Ba-Cu, Ba and Ni-Cr

  16. Geochemical geochronology and genesis of granite from Coronel Murta, Northeast of Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Soares, A.C.P.; Siga Junior, O.

    1987-01-01

    Geological, petrographic, geochemical (including rare-earth elements) and geochronological data of the Coronel Murta (Northeast Minas Gerais State) post-tectonic intrusive alkalic granites were summarized in order to discuss their genesis. This paper shows that Coronel Murta granites were generated by anatexis of dominantly metasedimentary rocks, in an ensialic environment, as the late results of an intraplate A-type subduction during the Brazilian Cycle. (author) [pt

  17. Contemporaneous deposition of phyllosilicates and sulfates: Using Australian acidic saline lake deposits to describe geochemical variability on Mars

    Science.gov (United States)

    Baldridge, A.M.; Hook, S.J.; Crowley, J.K.; Marion, G.M.; Kargel, J.S.; Michalski, J.L.; Thomson, B.J.; de Souza, Filho C.R.; Bridges, N.T.; Brown, A.J.

    2009-01-01

    Studies of the origin of the Martian sulfate and phyllosilicate deposits have led to the hypothesis that there was a marked, global-scale change in the Mars environment from circum-neutral pH aqueous alteration in the Noachian to an acidic evaporitic system in the late Noachian to Hesperian. However, terrestrial studies suggest that two different geochemical systems need not be invoked to explain such geochemical variation.Western Australian acidic playa lakes have large pH differences separated vertically and laterally by only a few tens of meters, demonstrating how highly variable chemistries can coexist over short distances in natural environments. We suggest diverse and variable Martian aqueous environments where the coetaneous formation of phyllosilicates and sulfates at the Australian sites are analogs for regions where phyllosilicates and sulfates coexist on Mars. In these systems, Fe and alkali earth phyllosilicates represent deep facies associated with upwelling neutral to alkaline groundwater, whereas aluminous phyllosilicates and sulfates represent near-surface evaporitic facies formed from more acidic brines. Copyright 2009 by the American Geophysical Union.

  18. Gas geochemical survey of long dormant Ciomadul volcano (South Harghita Mts., Romania): constraints on the flux and origin of fluids

    Science.gov (United States)

    Kis, Boglárka-Mercedesz; Ionescu, Artur; Harangi, Szabolcs; Palcsu, László; Etiope, Giuseppe; Baciu, Cǎlin

    2016-04-01

    The Ciomadul, located in the South Harghita Mountains (Eastern Carpathians, Romania) is the youngest volcano built by the Neogene volcanism in the Carpathian-Pannonian Region. The volcanic activity was characterized by an initial extrusive lava dome building period from about 200 ka to 100 ka followed by a more explosive eruption stage from 57 to 32 ka. Although the volcano seems to be inactive, several features (e.g. geophysical anomalies in the crust; fast remobilization of near solidus long lasting crystal mush prior to the past eruptions) suggest that melt-bearing magmatic body could still exist beneath the Ciomadul. This is supported by the abundance of dry gas emanations (CO2, CH4, H2S), CO2 rich mineral water springs and bubbling pools. The long-term observation of seemingly inactive, dormant volcanoes has become important in the past years (Ontake volcano-Japan, Colli Albani volcano-Italy). Gas-geochemical survey and monitoring (noble gases, isotopic composition of carbon species, flux measurements) of such volcanoes is an adequate tool in detecting changes in their volcanic plumbing system. Starting from 2015 we commenced a gas-monitoring study to constrain the origin of fluids at Ciomadul by measuring the flux of two gas-species and collecting the gas-phase from several mofettes and mineral water springs. A total of 46 sites have been surveyed, including 29 gas emanations (mofettes and bubbling pools), 3 drilled wells, 11 springs and 3 surface water sites. We provide the first complex CO2 and CH4 flux measurements in the area considering mofettes and bubbling pools. The CO2 flux values range between 10 and 264 kg/day while the CH4 flux has a range between 125 and 4723 g/day. Estimates of total CO2 and CH4 output into the atmosphere are ~229 and ~1.3 t/year, respectively. These values are consistent with other geothermal systems in Europe. The chemical composition of samples indicate CO2 content of up to 96.77%, CH4 content up to 1.42% and He content up to

  19. GEOCHEM-EZ: a chemical speciation program with greater power and flexibility

    Science.gov (United States)

    GEOCHEM –EZ is a multi-functional chemical speciation program, which was designed to replace the existing GEOCHEM-PC, a program that can only be used on DOS consoles. Chemical speciation programs, such as GEOCHEM (Sposito and Mattigod, 1980) and GEOCHEM-PC (Parker et al., 1995), have been excellent ...

  20. Uruguay mining Inventory: Geochemical prospecting results of Valentines mapping

    International Nuclear Information System (INIS)

    Spangenberg, J.; Filippini, J.

    1985-01-01

    This work is about geochemical prospecting carried out into the Uruguay mining inventory framework. In this case the survey was in Valentines mapping. Florida, Durazno and Treinta y Tres provinces of Uruguay .