WorldWideScience

Sample records for geophysical methods butsuri

  1. Chronology of petroleum geophysics; Sekiyu butsuri tansa nenpyo

    Energy Technology Data Exchange (ETDEWEB)

    Kametani, T

    1996-10-01

    A table, chronology of petroleum geophysics in overseas and in Japan, has been prepared for the convenience of checking events, which are thought to be important as notable affairs in application, success, and technical innovation. In overseas, successes in the 1920s were remarkable, when the US modern geophysical exploration made a start. Successes in determining the position of exploratory drilling by means of the gravity torsion balance, fan shooting seismic refraction method, and seismic reflection method occurred one after another. The USA has kept its situation stably as the number one by the seismic reflection method occurred most lately, and its life has been further elongated by adopting digital techniques. The CDP technique which became to be used simultaneously, and the seismic sources without using explosives, such as vibro-seismic source and air gun, extended the success of digital techniques drastically. In the future, the progress of 3-D exploration technology is expected. In Japan, about 18 years lag in the seismic reflection method is observed when compared with the USA. Japan has provided leading techniques in the shallow layer seismic reflection method and S-wave exploration. 40 refs., 1 tab.

  2. Fracture mapping in rock slope using geophysical instruments; Butsuri tansa ni yoru ganban shamennai no kiretsu bunpu hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Kurahashi, T; Inazaki, T [Public Works Research Institute, Tsukuba (Japan); Watanabe, S [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    An attempt was made to visualize distribution of cracks in a rock slope by applying geophysical survey onto a rock slope. Geophysical logging and seismic survey using the reflection method were used as the methods for the geophysical survey. The rock slope subjected to the survey is located in a gorge along the Yoshino river in Yamashiro Town, Tokushima Prefecture. The slope has a width of 25 m and a height of 30 m. Its overhang in a nose form may has a possibility of causing collapse due to sliding. Cracks developed by horizontal schistosity were detected by performing geophysical logging on VSP, calipers, natural gamma-ray spectra, temperature and borehole in a borehole drilled vertically from the top of the slope. The seismic survey using the reflection method detected the cracks by emphasizing joints in the perpendicular direction. A possibility was shown to visualize the crack distribution with high resolution by using the above geophysical survey on the rock slope. In order to detect the crack distribution with still higher resolution, development into a three-dimensional exploration in the future is desired, not to speak of improvement in signal receivers, and discussions on geometry. 1 ref., 6 figs.

  3. Estimated method of permeability in the granitic rocks by geophysical loggings; Butsuri kenso shuho ni yoru kakoganchu no tosuisei ni kansuru ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, K; Hashimoto, N. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)]Ogata, N. [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)

    1997-10-22

    Water permeability in granite is estimated by performing geophysical investigation using a 500m-deep test hole drilled in granitic rocks in the vicinity of a Tono mine. The investigation consists of flowmeter logging and geophysical logging. In flowmeter logging, a probe is moved up and down in the hole at a constant speed by use of a cable, and the cable speed and impeller revolution are used to workout the relative speed of the fluid in the hole. In the geophysical logging, a probe attached to the leading end of a logging cable is replaced with other probes so as to acquire different geophysical data. In a hole drilled in a crack-abundant rockbed such as a granitic rockbed, the inflow and outflow of ground water is governed mainly by water-permeable crack zones, and the result of the flowmeter logging show that this hole has three highly water-permeable zones. Using the results of the loggings, a correlative equation is worked out between changes in flow speed and changes in permeability index obtained by hydraulics tests. Among the various results achieved by the geophysical logging, a fine correlationship is found between an equation relative to permeability obtained using electricity and density and water-permeability indexes obtained by hydraulic tests conducted in situ. 4 refs., 8 figs., 1 tab.

  4. Case study of geostructural prospect of a tunnel by using geophysical methods; Butsuri tansa ni yoru tunnel chisan yosoku to jissai

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, H [Japan Railway Construction Public Corp., Tokyo (Japan); Kawakami, J [Taisei Construction Corp., Tokyo (Japan); Nagasue, I; Hiwatashi, S; Wakuno, M [Oyo Corp., Tokyo (Japan)

    1997-05-27

    A preliminary survey was carried out by combining elastic wave exploration (using a refraction method) and electrical exploration (using a resistivity imaging method) on a long tunnel planned in a granite distributed area. This paper describes a case of verifying geological condition in the area by using a trial survey well and horizontal boring. This tunnel goes through the Seburi mountainous area on the border of Fukuoka Prefecture and Saga Prefecture for a total distance of 12 km. The refraction method and the resistivity imaging method were selected from the necessity of identifying the weathering condition in natural ground, and distributions of fault crush zones and underground water in a section extending 560 m from the well entrance. As a result of comparing the natural ground condition interpreted from the geophysical survey results with the construction records, the fault was detected as a cracked or deformed section in the part where the resistivity value changes abruptly or where the resistivity is low. The tunnel natural ground classification showed a good correspondence with the elastic wave velocities. The largest flooding section showed a good agreement with the section where the resistivity changes suddenly to a lateral direction. Thus, the geological information interpreted from both surveys presented a good correspondence with the construction records, leading to a judgment that the prediction is possible. 3 refs., 4 figs., 5 tabs.

  5. A fractured rock geophysical toolbox method selection tool

    Science.gov (United States)

    Day-Lewis, F. D.; Johnson, C.D.; Slater, L.D.; Robinson, J.L.; Williams, J.H.; Boyden, C.L.; Werkema, D.D.; Lane, J.W.

    2016-01-01

    Geophysical technologies have the potential to improve site characterization and monitoring in fractured rock, but the appropriate and effective application of geophysics at a particular site strongly depends on project goals (e.g., identifying discrete fractures) and site characteristics (e.g., lithology). No method works at every site or for every goal. New approaches are needed to identify a set of geophysical methods appropriate to specific project goals and site conditions while considering budget constraints. To this end, we present the Excel-based Fractured-Rock Geophysical Toolbox Method Selection Tool (FRGT-MST). We envision the FRGT-MST (1) equipping remediation professionals with a tool to understand what is likely to be realistic and cost-effective when contracting geophysical services, and (2) reducing applications of geophysics with unrealistic objectives or where methods are likely to fail.

  6. Application of geophysical methods to investigation of old castle, especially of the moat; Joshi no chosa ni okeru butsuri tansa no tekiyo (horiato no tansa)

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, A; Karube, F; Kobayashi, M; Toge, M [OYO Corp., Tokyo (Japan)

    1996-05-01

    An explanation is made about the application of geophysical methods to the investigation of the ruins of old castles especially of their moats. Techniques currently in use for exploration of the ruins of castles are mainly underground radar exploration and electric exploration. The underground radar method sends electromagnetic waves through the ground and receives the reflection for a high-precision exploration of the layers shallow in the ground. Therefore, this method is suitable for probing the ruins of castles relatively shallow in the flat land, hills, and mountains. The electric method (resistivity image method) do the probing by use of the two-electrode arrangement, performs inverse analysis on the basis of the obtained data for the determination of the underground resistivity distribution, and displays the distribution in an image easy to read. This method, when there is a great separation between the two electrodes, explores relatively deep into the ground. Thanks to this feature, this method is effective in probing relatively wide and deep ruins of moats, that is, the ruins of moats of castles built in later years, especially of those then filled with water. 2 refs., 5 figs.

  7. Application of nuclear-geophysical methods to reserves estimation

    International Nuclear Information System (INIS)

    Bessonova, T.B.; Karpenko, I.A.

    1980-01-01

    On the basis of the analysis of reports dealing with calculations of mineral reserves considered are shortcomings in using nuclear-geophysical methods and in assessment of the reliability of geophysical sampling. For increasing efficiency of nuclear-geophysical investigations while prospecting ore deposits, it is advisable to introduce them widely instead of traditional geological sampling methods. For this purpose it is necessary to increase sensitivity and accuracy of radioactivity logging methods, to provide determination of certain elements in ores by these methods

  8. 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

    While numerical modeling has revolutionized our understanding of basin-scale hydrologic processes, such models rely almost exclusively on traditional measurements?rainfall, streamflow, and water-table elevations?for calibration and testing. Model calibration provides initial estimates of ground-water recharge. Calibrated models are important yet crude tools for addressing questions about the spatial and temporal distribution of recharge. An inverse approach to recharge estimation is taken of necessity, due to inherent difficulties in making direct measurements of flow across the water table. Difficulties arise because recharging fluxes are typically small, even in humid regions, and because the location of the water table changes with time. Deep water tables in arid and semiarid regions make recharge monitoring especially difficult. Nevertheless, recharge monitoring must advance in order to improve assessments of ground-water recharge. Improved characterization of basin-scale recharge is critical for informed water-resources management. Difficulties in directly measuring recharge have prompted many efforts to develop indirect methods. The mass-balance approach of estimating recharge as the residual of generally much larger terms has persisted despite the use of increasing complex and finely gridded large-scale hydrologic models. Geophysical data pertaining to recharge rates, timing, and patterns have the potential to substantially improve modeling efforts by providing information on boundary conditions, by constraining model inputs, by testing simplifying assumptions, and by identifying the spatial and temporal resolutions needed to predict recharge to a specified tolerance in space and in time. Moreover, under certain conditions, geophysical measurements can yield direct estimates of recharge rates or changes in water storage, largely eliminating the need for indirect measures of recharge. This appendix presents an overview of physically based, geophysical methods

  9. 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

  10. 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.

  11. 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

  12. Integrated geophysical-geochemical methods for archaeological prospecting

    OpenAIRE

    Persson, Kjell

    2005-01-01

    A great number of field measurements with different methods and instruments were conducted in attempts to develop a method for an optimal combination of various geochemical and geophysical methods in archaeological prospecting. The research presented in this thesis focuses on a study of how different anthropogenic changes in the ground can be detected by geochemical and geophysical mapping and how the results can be presented. A six-year pilot project, Svealand in Vendel and Viking periods (S...

  13. The application actualities and prospects of geophysical methods to uranium prospecting

    International Nuclear Information System (INIS)

    Liu Qingcheng

    2010-01-01

    Basic principles of geophysical methods to uranium prospect are briefly introduced, and the effects as well as problems in using those methods are analysed respectively. Combining with the increasing demand of uranium resources for Chinese nuclear power development and the higher requirements of geophysical techniques, the developing directions and the thoughts of geophysical techniques in uranium prospecting were proposed. A new pattern with producing, teaching and researching together is brought forward to develop advancing uranium prospecting key technologies and to break through technological bottlenecks depending on independent innovation. Integrated geophysical methods for prospecting uranium deposits are suggested. The method includes geophysical techniques as follows: gravity, magnetic, seismic, radioactive, remote sensing, and geochemical method in some proving grounds. Based on the experimental research, new uranium deposits prospecting models with efficient integrated geophysical methods can be established. (authors)

  14. Geophysical methods in protected environments. Electrical resistivity tomography

    International Nuclear Information System (INIS)

    Rubio Sánchez-Aguililla, F.M.; Ramiro-Camacho, A.; Ibarra Torre, P.

    2017-01-01

    There is a strong interest in protecting the environment with the aim of its long term preservation. Sometimes the heritage value of these natural areas is related to their biodiversity as there are restricted ecosystems that depend directly on them. In other cases there a singular geological record might exist, essential for the understanding of certain processes affecting the planet, such as volcanic events or glacial periods. To achieve the protection and conservation of these areas it is necessary to generate knowledge about the distribution of geological materials and groundwater masses, to study the parameters that dominate the behaviour of these systems and then define those elements that require special protection or attention. In these protected environments, research methods with a minimal environmental impact should be used. Therefore, indirect methods, such as geophysical techniques, are reliable and complementary tools with a minimum environmental impact and are therefore useful for research these unique areas. The IGME has conducted several geophysical surveys in different protected environments in Spain with the aim of achieving a better understanding, and thus facilitate their preservation and exploitation in a sustainable manner. In this paper we present a review of some case studies where geophysical methods have been used. In all the cases electrical resistivity tomography has been the axis of the geophysical research and stands out due to its great effectiveness. The main objective of this communication is to divulgate and increase awareness of the important role that these geophysical methods can play in the sustainable study of these unique places. [es

  15. uranium and thorium exploration by geophysical methods

    International Nuclear Information System (INIS)

    Yueksel, F.A.; Kanli, A.I.

    1997-01-01

    Radioactivity is often measured from the ground in mineral exploration. If large areas have to be investigated, it is often unsuitable to carry out the measurements with ground-bound expeditions. A geophysical method of gamma-ray spectrometry is generally applied for uranium exploration. Exploration of uranium surveys were stopped after the year of 1990 in Turkey. Therefore the real potential of uranium in Turkey have to be investigated by using the geophysical techniques

  16. Geophysical methods in uranium mining

    International Nuclear Information System (INIS)

    Koehler, K.

    1989-01-01

    In uranium prospecting, exploration, milling, and mining there is an urgent need to have information on the concentration of uranium at all steps of handling uranium containing materials. To gain this information in an effective way modern geophysical methods have to be applied. Publications of the IAEA and NEA in this field are reviewed in order to characterize the state of the art of these methods. 55 refs

  17. 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 ...

  18. Geophysical Exploration. New site exploration method

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Tsuneo; Otomo, Hideo; Sakayama, Toshihiko

    1988-07-25

    Geophysical exploration is used for geologic survey to serve purposes in civil engineering. New methods are being developed inside and outside Japan and are used to serve various purposes. This paper discusses recently developed techniques based on the measurement of seismic waves and electric potential. It also explains seismic tomography, radar tomography, and resistivity tomography which are included in the category of geotomography. At present, effort is being made to apply geophysical exploration technology to problems which were considered to be unsuitable for conventional exploration techniques. When such effort proceeds successfully, it is necessary to develop technology for presenting results quickly and exploration equipment which can work in various conditions. (10 figs, 15 refs)

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

    African Journals Online (AJOL)

    Abstract. The Application of various Geophysical Techniques for the assessment of the extent of ... ineffective Geophysical Method may not give true picture of the overall level of pollution in the .... stations shut down or maintenance which halt ...

  20. EXPLORATION BY MEANS OF GEOPHYSICAL METHODS OF GEOTHERMAL FIELDS AND CASE STUDIES

    Directory of Open Access Journals (Sweden)

    Züheyr KAMACI

    1997-01-01

    Full Text Available Geothermal energy which is one of the reuseable energy resources, can save as much as 77 million barrels of petroleum equivalent annually when used in the production of electricity and heating-environment. Geophysical exploration methods plays in important role in the fields of geothermal exploration, development and observational studies. Thermal and geoelectrical methods are the most effective methods which shows the temperature variation anomalies and mechanical drilling places. But, when the other methods of gravity, magnetic, radiometric, well geophysics and well logs can be used in conjunction with seismic tomography, apart from the mentioned geophysical exploration method, better results could be obtained. From the above mentioned facts various case history reports are given from our country and worldwide to determine geothermal energy resources by using geophysical exploration technique application. From these results of studies a 55 °C hot water artessian aquifer is found in the Uşak-Banaz geothermal field by applying geoelectrical methods.

  1. 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

  2. Application of comprehensive geophysical prospecting method in groundwater exploration

    Science.gov (United States)

    Yang, Fan; Gao, Pengju; Li, Dong; Ma, Hanwen; Cheng, Guoliang

    2018-01-01

    In order to solve the problem of shortage of water resources in northern Shaanxi, we selected rectangular large loop source transient electromagnetic method with high water affinity, and radioactive α measurement method which can delineate the water storage structure, comprehensive geophysical prospecting methods to look for groundwater. Algorithm has established a forward model, and compared all-time apparent resistivity in late-time apparent resistivity is better than late. We can find out the exact location of the groundwater and thus improving wells rate by comparatively using these two kinds of geophysical prospecting method. Hydrogeology drilling confirmed water inflow of a single well can be up to 40 m 3/h, it can fully cover native Domestic and Agricultural water, and provide an important basis for groundwater exploration.

  3. Geophysical methods for monitoring soil stabilization processes

    Science.gov (United States)

    Saneiyan, Sina; Ntarlagiannis, Dimitrios; Werkema, D. Dale; Ustra, Andréa

    2018-01-01

    Soil stabilization involves methods used to turn unconsolidated and unstable soil into a stiffer, consolidated medium that could support engineered structures, alter permeability, change subsurface flow, or immobilize contamination through mineral precipitation. Among the variety of available methods carbonate precipitation is a very promising one, especially when it is being induced through common soil borne microbes (MICP - microbial induced carbonate precipitation). Such microbial mediated precipitation has the added benefit of not harming the environment as other methods can be environmentally detrimental. Carbonate precipitation, typically in the form of calcite, is a naturally occurring process that can be manipulated to deliver the expected soil strengthening results or permeability changes. This study investigates the ability of spectral induced polarization and shear-wave velocity for monitoring calcite driven soil strengthening processes. The results support the use of these geophysical methods as soil strengthening characterization and long term monitoring tools, which is a requirement for viable soil stabilization projects. Both tested methods are sensitive to calcite precipitation, with SIP offering additional information related to long term stability of precipitated carbonate. Carbonate precipitation has been confirmed with direct methods, such as direct sampling and scanning electron microscopy (SEM). This study advances our understanding of soil strengthening processes and permeability alterations, and is a crucial step for the use of geophysical methods as monitoring tools in microbial induced soil alterations through carbonate precipitation.

  4. 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

  5. Location of Buried Mineshafts and Adits Using Reconnaissance Geophysical Methods

    Science.gov (United States)

    Culshaw, Martin; Donnelly, Laurance; McCann, David

    Britain has a long history of mining activity, which stretches back some 3000 years to the excavation of flint in East Anglia. The legacy of this long period of activity is the presence of many buried mineshafts and adits, whose location is often unknown precisely and in many cases not even recorded in historical mining records. As has been shown by Donnelly et al (2003) the discovery of a mineshaft in an area of housing development can have a profound effect on property values in its vicinity. Hence, urgent action must be taken to establish at the site investigation stage of a development to determine whether any mineshafts are present at the site so that remedial action can be taken before construction commences. A study of historical information and the drilling may well enable the developer to locate any suspected mineshafts and adits on his site. However, the use of geophysical reconnaissance methods across the whole site may well provide sufficient information to simplify the drilling programme and reduce its cost to a minimum. In this paper a number of rapid reconnaissance geophysical methods are described and evaluated in terms of their success in the location of buried mineshafts and adits. It has shown that a combination of ground conductivity and magnetic surveys provides a most effective approach on open sites in greenfield and brownfield areas. Ground penetrating radar and micro-gravity surveys have proved to be a valuable approach in urban areas where the use of many geophysical methods is prevented by the presence of various types of cultural noise. On a regional scale the infrared thermography method is being increasingly used but care must be taken to overcome certain environmental difficulties. The practical use of all these geophysical methods in the field is illustrated by a number of appropriate case histories.

  6. Geophysical methods for fracture characterization in and around potential sites for nuclear waste disposal

    International Nuclear Information System (INIS)

    Majer, E.L.; Lee, K.H.; Morrison, H.F.

    1992-08-01

    Historically, geophysical methods have been used extensively to successfully explore the subsurface for petroleum, gas, mineral, and geothermal resources. Their application, however, for site characterization, and monitoring the performance of near surface waste sites or repositories has been somewhat limited. Presented here is an overview of the geophysical methods that could contribute to defining the subsurface heterogeneity and extrapolating point measurements at the surface and in boreholes to volumetric descriptions in a fractured rock. In addition to site characterization a significant application of geophysical methods may be in performance assessment and in monitoring the repository to determine if the performance is as expected

  7. Geophysical methods for determining the geotechnical engineering properties of earth materials.

    Science.gov (United States)

    2010-03-01

    Surface and borehole geophysical methods exist to measure in-situ properties and structural : characteristics of earth materials. Application of such methods has demonstrated cost savings through : reduced design uncertainty and lower investigation c...

  8. Modeling and Evaluation of Geophysical Methods for Monitoring and Tracking CO2 Migration

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Jeff

    2012-11-30

    Geological sequestration has been proposed as a viable option for mitigating the vast amount of CO{sub 2} being released into the atmosphere daily. Test sites for CO{sub 2} injection have been appearing across the world to ascertain the feasibility of capturing and sequestering carbon dioxide. A major concern with full scale implementation is monitoring and verifying the permanence of injected CO{sub 2}. Geophysical methods, an exploration industry standard, are non-invasive imaging techniques that can be implemented to address that concern. Geophysical methods, seismic and electromagnetic, play a crucial role in monitoring the subsurface pre- and post-injection. Seismic techniques have been the most popular but electromagnetic methods are gaining interest. The primary goal of this project was to develop a new geophysical tool, a software program called GphyzCO2, to investigate the implementation of geophysical monitoring for detecting injected CO{sub 2} at test sites. The GphyzCO2 software consists of interconnected programs that encompass well logging, seismic, and electromagnetic methods. The software enables users to design and execute 3D surface-to-surface (conventional surface seismic) and borehole-to-borehole (cross-hole seismic and electromagnetic methods) numerical modeling surveys. The generalized flow of the program begins with building a complex 3D subsurface geological model, assigning properties to the models that mimic a potential CO{sub 2} injection site, numerically forward model a geophysical survey, and analyze the results. A test site located in Warren County, Ohio was selected as the test site for the full implementation of GphyzCO2. Specific interest was placed on a potential reservoir target, the Mount Simon Sandstone, and cap rock, the Eau Claire Formation. Analysis of the test site included well log data, physical property measurements (porosity), core sample resistivity measurements, calculating electrical permittivity values, seismic data

  9. 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

  10. Study of Shallow Low-Enthalpy Geothermal Resources Using Integrated Geophysical Methods

    Science.gov (United States)

    De Giorgi, Lara; Leucci, Giovanni

    2015-02-01

    The paper is focused on low enthalpy geothermal exploration performed in south Italy and provides an integrated presentation of geological, hydrogeological, and geophysical surveys carried out in the area of municipality of Lecce. Geological and hydrogeological models were performed using the stratigraphical data from 51 wells. A ground-water flow (direction and velocity) model was obtained. Using the same wells data, the ground-water annual temperature was modeled. Furthermore, the ground surface temperature records from ten meteorological stations were studied. This allowed us to obtain a model related to the variations of the temperature at different depths in the subsoil. Integrated geophysical surveys were carried out in order to explore the low-enthalpy geothermal fluids and to evaluate the results of the model. Electrical resistivity tomography (ERT) and self-potential (SP) methods were used. The results obtained upon integrating the geophysical data with the models show a low-enthalpy geothermal resource constituted by a shallow ground-water system.

  11. Geostatistical methods for rock mass quality prediction using borehole and geophysical survey data

    Science.gov (United States)

    Chen, J.; Rubin, Y.; Sege, J. E.; Li, X.; Hehua, Z.

    2015-12-01

    For long, deep tunnels, the number of geotechnical borehole investigations during the preconstruction stage is generally limited. Yet tunnels are often constructed in geological structures with complex geometries, and in which the rock mass is fragmented from past structural deformations. Tunnel Geology Prediction (TGP) is a geophysical technique widely used during tunnel construction in China to ensure safety during construction and to prevent geological disasters. In this paper, geostatistical techniques were applied in order to integrate seismic velocity from TGP and borehole information into spatial predictions of RMR (Rock Mass Rating) in unexcavated areas. This approach is intended to apply conditional probability methods to transform seismic velocities to directly observed RMR values. The initial spatial distribution of RMR, inferred from the boreholes, was updated by including geophysical survey data in a co-kriging approach. The method applied to a real tunnel project shows significant improvements in rock mass quality predictions after including geophysical survey data, leading to better decision-making for construction safety design.

  12. GPR survey, as one of the best geophysical methods for social and industrial needs

    Science.gov (United States)

    Chernov, Anatolii

    2016-04-01

    This paper is about ways and methods of applying non-invasive geophysical method - Ground penetrating radar (GPR) survey in different spheres of science, industry, social life and culture. Author would like to show that geological methods could be widely used for solving great variety of industrial, human safety and other problems. In that article, we take GPR survey as an example of such useful geophysical methods. It is a fact that investigation of near surface underground medium is important process, which influence on development of different spheres of science and social life: investigation of near surface geology (layering, spreading of rock types, identification of voids, etc.), hydrogeology (depth to water horizons, their thickness), preparation step for construction of roads and buildings (civil geology, engineering geology), investigation of cultural heritage (burial places, building remains,...), ecological investigations (land slides, variation in underground water level, etc.), glaciology. These tasks can be solved by geological methods, but as usual, geophysical survey takes a lot of time and energy (especially electric current and resistivity methods, seismic survey). Author claims that GPR survey can be performed faster than other geophysical surveys and results of GPR survey are informative enough to make proper conclusions. Some problems even cannot be solved without GPR. For example, identification of burial place (one of author's research objects): results of magnetic and electric resistivity tomography survey do not contain enough information to identify burial place, but according to anomalies on GPR survey radarograms, presence of burial place can be proven. Identification of voids and non-magnetic objects also hardly can be done by another non-invasive geophysics surveys and GPR is applicable for that purpose. GPR can be applied for monitoring of dangerous processes in geological medium under roads, buildings, parks and other places of human

  13. Geophysics-based method of locating a stationary earth object

    Science.gov (United States)

    Daily, Michael R [Albuquerque, NM; Rohde, Steven B [Corrales, NM; Novak, James L [Albuquerque, NM

    2008-05-20

    A geophysics-based method for determining the position of a stationary earth object uses the periodic changes in the gravity vector of the earth caused by the sun- and moon-orbits. Because the local gravity field is highly irregular over a global scale, a model of local tidal accelerations can be compared to actual accelerometer measurements to determine the latitude and longitude of the stationary object.

  14. Innovation of floating time domain electromagnetic method in the case of environmental geophysics

    Science.gov (United States)

    Nurjanah, Siti; Widodo

    2017-07-01

    Geophysics has some methods that can be used to reveal the subsurface structure of the earth. The physical features obtained from the acquisition then analyzed and interpreted, so that it can be a great lead to interpret the physical contents, determine its position and its distribution. Geophysical methods also can be used to help the environment contamination survey which is referred to environmental geophysics. There are many sources of pollution that can harm the nature, for example, the source in the form of solid waste, liquid waste containing heavy metals, or radioactive, and etc. As time passes, these sources might settle in any sedimentary area and become sediments. Time Domain Electromagnetic (TDEM) is a trustworthy method to detect the presence of conductive anomaly due to sediment accumulation. Innovation of floating TDEM created to maximize the potential of the method, so that it can be used in aquatic environments. The configuration of TDEM modified using pipes and tires during the process of measurements. We conducted numerical simulation using Marquardt and Occam Algorithms towards synthetic model to ensure the capability of the proposed design. The development of this innovation is expected to be very useful to repair the natural conditions, especially in the water.

  15. Introduction to the geophysical methods applicable to coal

    CSIR Research Space (South Africa)

    Fourie, S

    2015-01-01

    Full Text Available 2, it is the differences in the magnetic susceptibility of rocks that are exploited by the magnetic method. Units and terminology The internationally accepted unit for the magnetic field strength or intensity is the Tesla (named after Nikola Tesla..., the famous Serbian-American engineer and inventor). The Tesla is too large a unit for practical purposes and the nanotesla (nT, one billionth of a Tesla) is used in geophysical magnetic exploration. The name gamma (γ) was previously used instead...

  16. 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

  17. 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.

  18. 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)

  19. HMF-Geophysics - An Update

    Science.gov (United States)

    Crook, N.; Knight, R.; Robinson, D.

    2007-12-01

    There is growing recognition of the challenges we face, in many parts of the world, in finding and maintaining clean sources of water for human consumption and agricultural use, while balancing the needs of the natural world. Advancements in hydrologic sciences are needed in order to develop an improved understanding of the controls on the quantity, movement, and quality of water, thus enhancing our ability to better protect and manage our water resources. Geophysical methods can play a central role in these investigations. CUAHSI (Consortium of Universities for the Advancement of Hydrologic Sciences) is developing, with the support of the National Science Foundation, a Hydrologic Measurement Facility (HMF), which contains a Geophysics module, referred to as HMF-Geophysics. The Geophysics module will support and advance the use of geophysics for hydrologic applications. Currently in second year of a 3 year pilot study, the main aim of HMF-Geophysics is to develop the infrastructure necessary to provide geophysical techniques and the expertise to apply them correctly for the hydrological community. The current working model consists of a central HMF-Geophysics facility and a number of volunteer nodes. The latter consists of individuals at universities who have volunteered to be part of HMF-Geophysics by using their equipment, and/or software, and expertise, in research partnerships with hydrologists. In response to an inquiry the central facility takes on the evaluation of the potential of geophysics to the area of research/watershed. The central facility can then undertake a feasibility study to determine how/if geophysical methods could be of use, and to evaluate the "value-added" by geophysics to the science. Once it is clear that the geophysics can contribute in a significant way to addressing the science questions the central facility works with the hydrologist to set up the next step. Our assumption is that at this point, the hydrologist (perhaps with a

  20. The Monte Carlo method in mining nuclear geophysics: Pt. 1

    International Nuclear Information System (INIS)

    Burmistenko, Yu.N.; Lukhminsky, B.E.

    1990-01-01

    Prospects for using a new generation of neutron generators in mining geophysics are discussed. For their evaluation we use Monte Carlo computational methods with a special package of FORTRAN programs code-named MOK. Among the methods of pulsed neutron logging we discuss the method of time-dependent slowing down for the measurement of resonance neutron absorbers (mercury, tungsten, silver, gold, gadolinium, etc.) and time dependent spectral analysis of capture γ-rays (mercury). Among the neutron activation methods, we discuss the two source methods ( 252 Cf + neutron generator) and the method of spectral activation ratio for bauxites ( 27 Al/ 27 Mg or 27 Al/ 24m Na). (author)

  1. Determination of coal bed quality in wells by geophysical methods

    International Nuclear Information System (INIS)

    Popov, V.V.

    1974-01-01

    The dependence of the specific electric resistivity of coal and terrigenous material of the Donbass region on the degree of their metamorphism is discussed. From this dependence a method is derived to determine the metamorphism of coal from the effective specific resistivity of rocks by taking into account the self-polarisation and the density of the coal layers. The degree of metamorphism (from the coefficient of gas components in the heating mass of coal) is obtained with a standard deviation of 2.9%. Special physical properties of coal are related to its qualitative composition in a complex and very close way. With the whole complex of geophysical measurements the quality parameters can be estimated in more detail. For the Pavlogradsij-Petropavlovskij region of the Donbass non-linear mutli-dimensional relations between the quality parmaeters of coal are derived, and the measurements with standard geophysical methods (resistivity-, spontaneous-potential-, latero-, calibre- and gamma-gamma-log as well as cavernometry) are presented. The results obtained with these methods are tested by a comparison with 8 samples from mines. The standard deviation for the ash content is 3.73% (for core sampling 1.0%) and for the thickness of the plastic layer 3.63 mm (for core sampling 3.34mm)

  2. Application of geophysical methods in the indentification of landslides; Utilizacion de tecnicas geoficas en la identificacion de deslizamiento de ladera

    Energy Technology Data Exchange (ETDEWEB)

    Leon Gomez, A. M.; Tijera Carrion, A.; Ruiz Bravo, R.

    2014-07-01

    The aim of the current paper is to highlight which geophysical methods are the most widely used in the study of landslides nowadays. The investigation of landslides is one of the fundamental activities of Geotechnics. The development of that study can be carried out by applying geophysical methods of exploration. this article summarizes a state of the art previously done in a more extensive review of geophysical techniques which are used in the characterisation of landslides. Formerly, Jongmans and Garambois (2007) had reviewed applications of the main geophysical techniques to landslide characterisation. In their article, the authors compiled documentation that had been published after 1990 until 2006. Following on that paper, this study makes a review of several articles from 2007 until recent papers (2013), throughout a quantitative analysis of the most applied geophysical methods. the research carried out has allowed not only to point out the main geophysical techniques currently applied for landslides investigation, but also to establish which are the most suitable depending on their composition (soils or rocks). As an example of the analysis carried out from the different publication reviewed, and as a case of application of geophysical techniques to the study of landslides, the study developed by the Geotechnical Laboratory CEDEX on a Landslide is presented in this article. (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 Methods for Monitoring Temperature Changes in Shallow Low Enthalpy Geothermal Systems

    Directory of Open Access Journals (Sweden)

    Thomas Hermans

    2014-08-01

    Full Text Available Low enthalpy geothermal systems exploited with ground source heat pumps or groundwater heat pumps present many advantages within the context of sustainable energy use. Designing, monitoring and controlling such systems requires the measurement of spatially distributed temperature fields and the knowledge of the parameters governing groundwater flow (permeability and specific storage and heat transport (thermal conductivity and volumetric thermal capacity. Such data are often scarce or not available. In recent years, the ability of electrical resistivity tomography (ERT, self-potential method (SP and distributed temperature sensing (DTS to monitor spatially and temporally temperature changes in the subsurface has been investigated. We review the recent advances in using these three methods for this type of shallow applications. A special focus is made regarding the petrophysical relationships and on underlying assumptions generally needed for a quantitative interpretation of these geophysical data. We show that those geophysical methods are mature to be used within the context of temperature monitoring and that a combination of them may be the best choice regarding control and validation issues.

  5. 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.

  6. Porosity measurements of crystalline rocks by laboratory and geophysical methods

    International Nuclear Information System (INIS)

    Alexander, J.; Hall, D.H.; Storey, B.C.

    1981-12-01

    Porosity values of igneous and metamorphic crystalline rocks have been determined from core samples taken at specific depths from Altnabreac, by a combination of laboratory and geophysical techniques. Using resaturation and mercury injection methods in three laboratories within I.G.S., porosity values have been derived and the effect of variations in the measuring techniques and results obtained have been compared. Comparison of inter-laboratory porosity values illustrates that systematic errors are present, resulting in higher porosity values for samples subjected to re-testing. This is considered to be caused by the variable nature of the initial samples combined with the inability to completely dry or resaturate samples during a second testing. Geophysical techniques for determining in situ porosity using the neutron log have been carried out in borehole ALA. The neutron log has been calibrated with laboratory derived porosity values and an empirical formula derived enabling porosity values to be ascribed throughout the logged borehole ALA. Comparison of the porosity results from Altnabreac with crystalline samples elsewhere in America, Europe and the U.K. suggest that porosities at Altnabreac are lower than average. However, very few publications concerned with water movement in crystalline areas actually state the method used. (author)

  7. GEOLOGICAL-GEOPHYSICAL EXPLORATION OF THE BAUXITE DEPOSITS APPLICATION OF THE SHALLOW SEIZMIC REFLECTION METHOD

    Directory of Open Access Journals (Sweden)

    Ivan Dragičević

    1991-12-01

    Full Text Available The exploration of bauxite deposits in the region of the carbonaceous Dinarides has been performed by using different geological and geophysical methods. Deposits laying shallower or deeper below the roof sediments have so far most often been discovered by expensive drilling methods in a corresponding grid. Complex geological explorations have led to a series of valuable data thus enabling the application of other much more economical methods as well. In the region of the bauxite sedimentary basin Mesihovina-Rakitno, western Herzegovina, at the site of Studena vrila - after extensive geological explorations - a conclusion was drawn that the shallow seismic reflection geophysical method as well might be successfully applied in locating new bauxite deposits. In the paper, the geological framework of the bauxite deposits occurrences, stipulating the selection of this methode, will be presented. Measurements were performed on a known deposit (L-84, Povaljenica, completely defined by exploration drilling. The obtained results justify the selection of the shallow seismic reflection method as one of the methods for exploring bauxite deposits beneath the roof beds.

  8. Definition of a critical confining zone using surface geophysical methods

    International Nuclear Information System (INIS)

    Eddy-Dilek, C.A.; Hoekstra, P.; Harthill, N.; Blohm, M.; Phillips, D.R.

    1996-01-01

    Definition of the hydrogeologic framework in layered sediments of fluvial and deltaic origin is a difficult challenge for environmental characterization and remediation programs due to the lithologic and stratigraphic heterogeneities inherent in these settings. These heterogeneties often control contaminant transport and the effectiveness of remediation alternatives, Surface geophysical surveys can be cost-effective methods for characterization, but individual methods have inherent limitations in resolution and sensitivity. A synergistic approach, utilizing two geophysical survey methods was applied, to define and examine the nature and extent of a deep confining zone of regulatory importance, the Crouch Branch Confining Unit, in Coastal Plain sediments at the Savannah River Site. TDEM accurately maps the overall conductance (product of thickness and electrical conductivity) of a confining zone clay facies; from variation in conductance, changes in lithology of the conforming zone can be inferred. Shear wave seismic reflection surveys map the depth to the clay layers, and the clay layer thickness, but provides little information on the lithologic nature of the confining zone. Integrated interpretation of the combined data set (including all available borehole logs) allows for delineation of the lateral and vertical extent of clay-dominated zones, sand-dominated zones, key stratigraphic horizons, and erosional features associated with unconformities. This approach has resulted in the collection of critical information that will be used to optimize remedial system design, representing a significant cost savings to environmental restoration programs at the Savannah River Site

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

    International Nuclear Information System (INIS)

    2013-01-01

    through the use of effective exploration techniques. Geophysical methods with the capability of mapping surface and subsurface parameters in relation to uranium deposition and accumulation are proving to be vital components of current exploration efforts around the world. There is continuous development and improvement of technical and scientific disciplines using measuring instruments and spatially referenced data processing techniques. Newly designed geophysical instruments and their applications in uranium exploration are contributing to an increased probability of successful discoveries. Dissemination of information on advances in geophysical techniques encourages new strategies and promotes new approaches toward uranium exploration. Meetings and conferences organized by the IAEA, collecting the experience of participating countries, as well as its publications and the International Nuclear Information System, play an important role in the dissemination of knowledge of all aspects of the nuclear fuel cycle. The purpose of this report is to highlight advances in airborne and ground geophysical techniques, succinctly describing modern geophysical methods and demonstrating the application of techniques through examples. The report also provides some basic concepts of radioactivity, nuclear radiation and interaction with matter.

  10. Application of surface geophysics to ground-water investigations

    Science.gov (United States)

    Zohdy, Adel A.R.; Eaton, Gordon P.; Mabey, Don R.

    1974-01-01

    This manual reviews the standard methods of surface geophysics applicable to ground-water investigations. It covers electrical methods, seismic and gravity methods, and magnetic methods. The general physical principles underlying each method and its capabilities and limitations are described. Possibilities for non-uniqueness of interpretation of geophysical results are noted. Examples of actual use of the methods are given to illustrate applications and interpretation in selected geohydrologic environments. The objective of the manual is to provide the hydrogeologist with a sufficient understanding of the capabilities, imitations, and relative cost of geophysical methods to make sound decisions as to when to use of these methods is desirable. The manual also provides enough information for the hydrogeologist to work with a geophysicist in designing geophysical surveys that differentiate significant hydrogeologic changes.

  11. The application of geophysical methods to archaeological prospection

    Energy Technology Data Exchange (ETDEWEB)

    Linford, Neil [Geophysics Team, English Heritage, Fort Cumberland, Eastney, Portsmouth PO4 9LD (United Kingdom)

    2006-07-15

    The aim of this review is to combine the almost universal fascination we share for our past with the comparatively recent, in archaeological terms, application of geophysical prospection methods. For their success, each of these methods relies upon a physical contrast to exist between the buried archaeological feature and the properties of the surrounding subsoil. Understanding the archaeological origin of such physical contrasts, in terms of density, thermal conductivity, electrical resistance, magnetic or dielectric properties, remains fundamental to an appreciation of the discipline. This review provides a broad introduction to the subject area acknowledging the historical development of the discipline and discusses each of the major techniques in turn: earth resistance, magnetic and electromagnetic methods (including ground penetrating radar), together with an appreciation of more esoteric approaches, such as the use of micro-gravity survey to detect buried chambers and voids. The physical principles and field instrumentation involved for the acquisition of data with each method are considered and fully illustrated with case histories of results from the English Heritage archives.

  12. The application of geophysical methods to archaeological prospection

    International Nuclear Information System (INIS)

    Linford, Neil

    2006-01-01

    The aim of this review is to combine the almost universal fascination we share for our past with the comparatively recent, in archaeological terms, application of geophysical prospection methods. For their success, each of these methods relies upon a physical contrast to exist between the buried archaeological feature and the properties of the surrounding subsoil. Understanding the archaeological origin of such physical contrasts, in terms of density, thermal conductivity, electrical resistance, magnetic or dielectric properties, remains fundamental to an appreciation of the discipline. This review provides a broad introduction to the subject area acknowledging the historical development of the discipline and discusses each of the major techniques in turn: earth resistance, magnetic and electromagnetic methods (including ground penetrating radar), together with an appreciation of more esoteric approaches, such as the use of micro-gravity survey to detect buried chambers and voids. The physical principles and field instrumentation involved for the acquisition of data with each method are considered and fully illustrated with case histories of results from the English Heritage archives

  13. Investigating lithological and geophysical relationships with applications to geological uncertainty analysis using Multiple-Point Statistical methods

    DEFF Research Database (Denmark)

    Barfod, Adrian

    The PhD thesis presents a new method for analyzing the relationship between resistivity and lithology, as well as a method for quantifying the hydrostratigraphic modeling uncertainty related to Multiple-Point Statistical (MPS) methods. Three-dimensional (3D) geological models are im...... is to improve analysis and research of the resistivity-lithology relationship and ensemble geological/hydrostratigraphic modeling. The groundwater mapping campaign in Denmark, beginning in the 1990’s, has resulted in the collection of large amounts of borehole and geophysical data. The data has been compiled...... in two publicly available databases, the JUPITER and GERDA databases, which contain borehole and geophysical data, respectively. The large amounts of available data provided a unique opportunity for studying the resistivity-lithology relationship. The method for analyzing the resistivity...

  14. Application of the geophysical and geochemical methods to the research for uranium; Application a la recherche de l'uranium des methodes geophysiques et geochimiques

    Energy Technology Data Exchange (ETDEWEB)

    Gangloff, A M; Collin, C R; Grimbert, A; Sanselme, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    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) [French] Depuis 1954, au CEA, a l'observation geologique directe et aux mesures radiometriques, sont venues s'ajouter des methodes relevant de la geophysique et de la geochimie. La prospection geophysique apporte des precisions sur les structures tectoniques auxquelles sont lies les gisements d'uranium fran is et sur la notion de zones favorables. Aux methodes indirectes de la geophysique, la prospection geochimique ajoute des precisions sur la repartition de l'uranium en traces dans les sols, cette methode est directe et specifique. Le dosage de l'uranium dans les eaux et les alluvions trouve son application dans la prospection de reconnaissance. (auteur)

  15. 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

  16. Reconstructing former urban environments by combining geophysical electrical methods and geotechnical investigations—an example from Chania, Greece

    International Nuclear Information System (INIS)

    Soupios, P M; Vallianatos, F; Loupasakis, C

    2008-01-01

    Nowadays, geophysical prospecting is implemented in order to resolve a diversity of geological, hydrogeological, environmental and geotechnical problems. Although plenty of applications and a lot of research have been conducted in the countryside, only a few cases have been reported in the literature concerning urban areas, mainly due to high levels of noise present that aggravate most of the geophysical methods or due to spatial limitations that hinder normal method implementation. Among all geophysical methods, electrical resistivity tomography has proven to be a rapid technique and the most robust with regard to urban noise. This work presents a case study in the urban area of Chania (Crete Island, Greece), where electrical resistivity tomography (ERT) has been applied for the detection and identification of possible buried ancient ruins or other man-made structures, prior to the construction of a building. The results of the detailed geophysical survey indicated eight areas of interest providing resistivity anomalies. Those anomalies were analysed and interpreted combining the resistivity readings with the geotechnical borehole data and the historical bibliographic reports—referring to the 1940s (Xalkiadakis 1997 Industrial Archaeology in Chania Territory pp 51–62). The collected ERT-data were processed by applying advanced algorithms in order to obtain a 3D-model of the study area that depicts the interesting subsurface structures more clearly and accurately

  17. Design and Construction of Equipment for Applying the Geophysical Prospecting Method Electric Tomography

    Directory of Open Access Journals (Sweden)

    Fabio Héctor Giraldo Sánchez

    2013-06-01

    Full Text Available Outlines the procedure for the design and construction of electric equipment for geophysical prospecting through electrical tomography method. The team is of average power, ensuring exploration depths quite suitable for applications and commercial and geotechnical studies. The device is essentially a DC voltage source of 500 volts that is able to provide a maximum current of 1 amp. It also contains a small charge current source of electrical currents counteract naturally found in the subsoil and are manifested as a difference in the surface potential. A general explanation of the geophysical method in question, helps to understand the basic principles of operation of the equipment and functions to be fulfilled. After building the team, we conducted a field data acquisition, in area near the town of Gachancipa Cundinamarca. The data from this equipment are processed with specialized software. The images obtained with the software presents the distributions of subsurface resistivity can be associated with the possible structures and geology of the study area.

  18. Assessment of geothermal energy potential by geophysical methods: Nevşehir Region, Central Anatolia

    Science.gov (United States)

    Kıyak, Alper; Karavul, Can; Gülen, Levent; Pekşen, Ertan; Kılıç, A. Rıza

    2015-03-01

    In this study, geothermal potential of the Nevşehir region (Central Anatolia) was assessed by using vertical electrical sounding (VES), self-potential (SP), magnetotelluric (MT), gravity and gravity 3D Euler deconvolution structure analysis methods. Extensive volcanic activity occurred in this region from Upper Miocene to Holocene time. Due to the young volcanic activity Nevşehir region can be viewed as a potential geothermal area. We collected data from 54 VES points along 5 profiles, from 28 MT measurement points along 2 profiles (at frequency range between 320 and 0.0001 Hz), and from 4 SP profiles (total 19 km long). The obtained results based on different geophysical methods are consistent with each other. Joint interpretation of all geological and geophysical data suggests that this region has geothermal potential and an exploration well validated this assessment beyond doubt.

  19. 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

  20. Application of geophysical methods to gold prospecting in Minas de Corrales, Uruguay

    International Nuclear Information System (INIS)

    Costa, Antonio Flavio U.; Dias, Rogerio Aguirre; Barcelos, Andre B.B. de

    1993-01-01

    Geophysical methods were tested in San Gregorio gold mine, Minas de Corrales, north region of Uruguay. The ores are mainly stockworks, sheeted veinlet zones, ore shoot and disseminated sulfides types, situated in a silicated and carbonated shear zone structure, over granitic mylonites, quartz diorites, quartz-feldspathic breccia, basic rocks and quartz veins. Magnetic and radiometric methods were applied . VLF and EM34-3 detected the high resistivity silicated and carbonated zone and IP detected a weak PFE anomaly associated with pyrite/gold zone. (author)

  1. Local regression type methods applied to the study of geophysics and high frequency financial data

    Science.gov (United States)

    Mariani, M. C.; Basu, K.

    2014-09-01

    In this work we applied locally weighted scatterplot smoothing techniques (Lowess/Loess) to Geophysical and high frequency financial data. We first analyze and apply this technique to the California earthquake geological data. A spatial analysis was performed to show that the estimation of the earthquake magnitude at a fixed location is very accurate up to the relative error of 0.01%. We also applied the same method to a high frequency data set arising in the financial sector and obtained similar satisfactory results. The application of this approach to the two different data sets demonstrates that the overall method is accurate and efficient, and the Lowess approach is much more desirable than the Loess method. The previous works studied the time series analysis; in this paper our local regression models perform a spatial analysis for the geophysics data providing different information. For the high frequency data, our models estimate the curve of best fit where data are dependent on time.

  2. Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Keating, Kristina [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Slater, Lee [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Ntarlagiannis, Dimitris [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Williams, Kenneth H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division

    2015-02-24

    This documents contains the final report for the project "Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods" (DE-SC0007049) Executive Summary: Our research aimed to develop borehole measurement techniques capable of monitoring subsurface processes, such as changes in pore geometry and iron/sulfur geochemistry, associated with remediation of heavy metals and radionuclides. Previous work has demonstrated that geophysical method spectral induced polarization (SIP) can be used to assess subsurface contaminant remediation; however, SIP signals can be generated from multiple sources limiting their interpretation value. Integrating multiple geophysical methods, such as nuclear magnetic resonance (NMR) and magnetic susceptibility (MS), with SIP, could reduce the ambiguity of interpretation that might result from a single method. Our research efforts entails combining measurements from these methods, each sensitive to different mineral forms and/or mineral-fluid interfaces, providing better constraints on changes in subsurface biogeochemical processes and pore geometries significantly improving our understanding of processes impacting contaminant remediation. The Rifle Integrated Field Research Challenge (IFRC) site was used as a test location for our measurements. The Rifle IFRC site is located at a former uranium ore-processing facility in Rifle, Colorado. Leachate from spent mill tailings has resulted in residual uranium contamination of both groundwater and sediments within the local aquifer. Studies at the site include an ongoing acetate amendment strategy, native microbial populations are stimulated by introduction of carbon intended to alter redox conditions and immobilize uranium. To test the geophysical methods in the field, NMR and MS logging measurements were collected before, during, and after acetate amendment. Next, laboratory NMR, MS, and SIP measurements

  3. 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.

  4. Detection of hazardous cavities with combined geophysical methods

    Science.gov (United States)

    Hegymegi, Cs.; Nyari, Zs.; Pattantyus-Abraham, M.

    2003-04-01

    Unknown near-surface cavities often cause problems for municipal communities all over the world. This is the situation in Hungary in many towns and villages, too. Inhabitants and owners of real estates (houses, cottages, lands) are responsible for the safety and stability of their properties. The safety of public sites belongs to the local municipal community. Both (the owner and the community) are interested in preventing accidents. Near-surface cavities (unknown caves or earlier built and forgotten cellars) usually can be easily detected by surface geophysical methods. Traditional and recently developed measuring techniques in seismics, geoelectrics and georadar are suitable for economical investigation of hazardous, potentially collapsing cavities, prior to excavation and reinforcement. This poster will show some example for detection of cellars and caves being dangerous for civil population because of possible collapse under public sites (road, yard, playground, agricultural territory, etc.). The applied and presented methods are ground penetrating radar, seismic surface tomography and analysis of single traces, geoelectric 2D and 3D resistivity profiling. Technology and processing procedure will be presented.

  5. The application of nuclear geophysics method to evaluate the geological environment of nuclear waste repository

    International Nuclear Information System (INIS)

    Fang, Fang; Xiaoqin, Wang; Kuanliang, Li; Xinsheng, Hou; Jingliang, Zhu; Binxin, Hu

    2002-01-01

    'Cleanly land should be given back ground.' This is a task while nuclear engineering have to be retired. We applied the nuclear geophysics methods and combined with geology, hydrology, geochemistry, and other methods, to evaluate the environment of nuclear waste repository. It is the important work to renovate environment and prepare technology before ex-service of the nuclear engineering

  6. GEOLOGICAL-GEOPHYSICAL EXPLORATION OF THE BAUXITE DEPOSITS APPLICATION OF THE SHALLOW SEIZMIC REFLECTION METHOD

    OpenAIRE

    Ivan Dragičević; Miroslav Andrić; Ivan Blašković

    1991-01-01

    The exploration of bauxite deposits in the region of the carbonaceous Dinarides has been performed by using different geological and geophysical methods. Deposits laying shallower or deeper below the roof sediments have so far most often been discovered by expensive drilling methods in a corresponding grid. Complex geological explorations have led to a series of valuable data thus enabling the application of other much more economical methods as well. In the region of the bauxite sedimentary ...

  7. The development of efficient numerical time-domain modeling methods for geophysical wave propagation

    Science.gov (United States)

    Zhu, Lieyuan

    This Ph.D. dissertation focuses on the numerical simulation of geophysical wave propagation in the time domain including elastic waves in solid media, the acoustic waves in fluid media, and the electromagnetic waves in dielectric media. This thesis shows that a linear system model can describe accurately the physical processes of those geophysical waves' propagation and can be used as a sound basis for modeling geophysical wave propagation phenomena. The generalized stability condition for numerical modeling of wave propagation is therefore discussed in the context of linear system theory. The efficiency of a series of different numerical algorithms in the time-domain for modeling geophysical wave propagation are discussed and compared. These algorithms include the finite-difference time-domain method, pseudospectral time domain method, alternating directional implicit (ADI) finite-difference time domain method. The advantages and disadvantages of these numerical methods are discussed and the specific stability condition for each modeling scheme is carefully derived in the context of the linear system theory. Based on the review and discussion of these existing approaches, the split step, ADI pseudospectral time domain (SS-ADI-PSTD) method is developed and tested for several cases. Moreover, the state-of-the-art stretched-coordinate perfect matched layer (SCPML) has also been implemented in SS-ADI-PSTD algorithm as the absorbing boundary condition for truncating the computational domain and absorbing the artificial reflection from the domain boundaries. After algorithmic development, a few case studies serve as the real-world examples to verify the capacities of the numerical algorithms and understand the capabilities and limitations of geophysical methods for detection of subsurface contamination. The first case is a study using ground penetrating radar (GPR) amplitude variation with offset (AVO) for subsurface non-aqueous-liquid (NAPL) contamination. The

  8. 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)

  9. Chaos theory in geophysics: past, present and future

    International Nuclear Information System (INIS)

    Sivakumar, B.

    2004-01-01

    The past two decades of research on chaos theory in geophysics has brought about a significant shift in the way we view geophysical phenomena. Research on chaos theory in geophysics continues to grow at a much faster pace, with applications to a wide variety of geophysical phenomena and geophysical problems. In spite of our success in understanding geophysical phenomena also from a different (i.e. chaotic) perspective, there still seems to be lingering suspicions on the scope of chaos theory in geophysics. The goal of this paper is to present a comprehensive account of the achievements and status of chaos theory in geophysics, and to disseminate the hope and scope for the future. A systematic review of chaos theory in geophysics, covering a wide spectrum of geophysical phenomena studied (e.g. rainfall, river flow, sediment transport, temperature, pressure, tree ring series, etc.), is presented to narrate our past achievements not only in understanding and predicting geophysical phenomena but also in improving the chaos identification and prediction techniques. The present state of chaos research in geophysics (in terms of geophysical phenomena, problems, and chaos methods) and potential for future improvements (in terms of where, why and possibly how) are also highlighted. Our popular views of nature (i.e. stochastic and deterministic), and of geophysical phenomena in particular, are discussed, and the usefulness of chaos theory as a bridge between such views is also put forth

  10. The Bolmen tunnel project - evaluation of geophysical site investigation methods

    International Nuclear Information System (INIS)

    Stanfors, R.

    1987-12-01

    The report presents geophysical measurements along and adjacent to the tunnel and an evaluation of the ability of the various methods to permit prediction of rock mass parameters of significance to stability and water bearing ability. The evaluation shows that, using airborne electro-magnetic surveys, it was possible to indicate about 80% of alla the zones of weakness more than 50 m wide in the tunnel. Airborne magnetic surveys located about 90% of all dolerite dykes more than 10 m wide. Ground-level VLF and Slingram methods of electro-magnetic measurement indicated 75% and 85% respectively of all zones of weakness more than 50 m wide. Resistivity methods were successfully used to locate clay filled and water-bearing fracture zones. About 75% of the length of tunnel over which resistivity values below 500 ohm m were measured required shotcrete support and pre-grouting. (orig./DG)

  11. Geophysical investigations in the Syyry area, Finland

    International Nuclear Information System (INIS)

    Heikkinen, E.; Kurimo, M.

    1992-12-01

    Investigations were carried out at the Syyry site at Sievi using geological, geophysical, geohydrological and geochemical methods in 1987-1991 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

  12. Geophysical investigations in the Olkiluoto area, Finland

    International Nuclear Information System (INIS)

    Heikkinen, E.; Paananen, M.

    1992-12-01

    Investigations were carried out at the Olkiluoto site at Eurajoki using geological, geophysical, geohydrological and geochemical methods in 1987-1992 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

  13. Geophysical investigations in the Kivetty area, Finland

    International Nuclear Information System (INIS)

    Heikkinen, E.; Paananen, M.; Oehberg, A.; Front, K.; Okko, O.; Pitkaenen, P.

    1992-09-01

    Investigations were carried out at Kivetty site in Konginkangas, in central Finland, by geological, geophysical, geohydrological and geochemical methods in 1987-1991 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 of the bedrock to a depth of one kilometre

  14. Fifth national outdoor action conference on aquifer restoration, ground water monitoring, and geophysical methods

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This book presents papers on technology in ground water sampling, monitoring, and remediation and geophysical techniques. The section on monitoring and remediation covers monitoring case studies, monitoring waste disposal sites, petroleum recovery, techniques in aquifer remediation, mathematical analysis of remedial techniques, vacuum extraction, bioremediation, and monitoring techniques. The section on sampling covers measurement variability, microbial sampling, vadose zone sampling, sampling with hydraulic probes, unusual sampling problems and equipment, and data management. A section on geophysics covers geophysics and site characterization, and geophysics and mining. The focus is on hazardous organic compounds. Individual articles are abstracted separately

  15. Aquifer Recharge Estimation In Unsaturated Porous Rock Using Darcian And Geophysical Methods.

    Science.gov (United States)

    Nimmo, J. R.; De Carlo, L.; Masciale, R.; Turturro, A. C.; Perkins, K. S.; Caputo, M. C.

    2016-12-01

    Within the unsaturated zone a constant downward gravity-driven flux of water commonly exists at depths ranging from a few meters to tens of meters depending on climate, medium, and vegetation. In this case a steady-state application of Darcy's law can provide recharge rate estimates.We have applied an integrated approach that combines field geophysical measurements with laboratory hydraulic property measurements on core samples to produce accurate estimates of steady-state aquifer recharge, or, in cases where episodic recharge also occurs, the steady component of recharge. The method requires (1) measurement of the water content existing in the deep unsaturated zone at the location of a core sample retrieved for lab measurements, and (2) measurement of the core sample's unsaturated hydraulic conductivity over a range of water content that includes the value measured in situ. Both types of measurements must be done with high accuracy. Darcy's law applied with the measured unsaturated hydraulic conductivity and gravitational driving force provides recharge estimates.Aquifer recharge was estimated using Darcian and geophysical methods at a deep porous rock (calcarenite) experimental site in Canosa, southern Italy. Electrical Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES) profiles were collected from the land surface to water table to provide data for Darcian recharge estimation. Volumetric water content was estimated from resistivity profiles using a laboratory-derived calibration function based on Archie's law for rock samples from the experimental site, where electrical conductivity of the rock was related to the porosity and water saturation. Multiple-depth core samples were evaluated using the Quasi-Steady Centrifuge (QSC) method to obtain hydraulic conductivity (K), matric potential (ψ), and water content (θ) estimates within this profile. Laboratory-determined unsaturated hydraulic conductivity ranged from 3.90 x 10-9 to 1.02 x 10-5 m

  16. Informing groundwater models with near-surface geophysical data

    DEFF Research Database (Denmark)

    Herckenrath, Daan

    Over the past decade geophysical methods have gained an increased popularity due to their ability to map hydrologic properties. Such data sets can provide valuable information to improve hydrologic models. Instead of using the measured geophysical and hydrologic data simultaneously in one inversion...... approach, many of the previous studies apply a Sequential Hydrogeophysical Inversion (SHI) in which inverted geophysical models provide information for hydrologic models. In order to fully exploit the information contained in geophysical datasets for hydrological purposes, a coupled hydrogeophysical...... inversion was introduced (CHI), in which a hydrologic model is part of the geophysical inversion. Current CHI-research has been focussing on the translation of simulated state variables of hydrologic models to geophysical model parameters. We refer to this methodology as CHI-S (State). In this thesis a new...

  17. Multiple geophysical methods examining neotectonic blind structures in the Maradona valley, Central Precordillera (Argentina)

    Science.gov (United States)

    Lara, Gabriela; Klinger, Federico Lince; Perucca, Laura; Rojo, Guillermo; Vargas, Nicolás; Leiva, Flavia

    2017-08-01

    A high-resolution superficial geophysical study was carried out in an area of the retroarc region of the Andes mountains, located in the southwest of San Juan Province (31°45‧ S, 68°50‧ W), Central Precordillera of Argentina. The main objectives of this study were to confirm the presence of blind neotectonic structures and characterize them by observing variations in magnetic susceptibility, density and p-wave velocities. Geological evidence demonstrates the existence of a neotectonic fault scarps affecting Quaternary alluvial deposits in eastern piedmont of de Las Osamentas range, in addition to direct observation of the cinematic of this feature in several natural exposures. The Maradona valley is characterized by the imbricated eastern-vergence Maradona Fault System that uplifts Neogene sedimentary rocks (Albarracín Formation) over Quaternary (Late Pleistocene-Holocene) alluvial deposits. The combined application of different geophysical methods has allowed the characterization of a blind fault geometry also identified on a natural exposure. The magnetic data added to the gravimetric model, and its integration with a seismic profile clearly shows the existence of an anomalous zone, interpreted as uplifted blocks of Miocene sedimentary rocks of Formation Albarracín displaced over Quaternary deposits. The application and development of different geophysical methods, together with geological studies allow to significantly improving the knowledge of an area affected by Quaternary tectonic activity. Finally, this multidisciplinary study, applied in active blind structures is very relevant for future seismic hazard analysis on areas located very close to populated centers.

  18. 3D modelling of the electromagnetic response of geophysical targets using the FDTD method

    Energy Technology Data Exchange (ETDEWEB)

    Debroux, P.S. [Univ. of Arizona, Tucson, AZ (United States). Mining and Geological Engineering Dept.

    1996-05-01

    A publicly available and maintained electromagnetic finite-difference time domain (FDTD) code has been applied to the forward modelling of the response of 1D, 2D and 3D geophysical targets to a vertical magnetic dipole excitation. The FDTD method is used to analyze target responses in the 1 MHz to 100 MHz range, where either conduction or displacement currents may have the controlling role. The response of the geophysical target to the excitation is presented as changes in the magnetic field ellipticity. The results of the FDTD code compare favorably with previously published integral equation solutions of the response of 1D targets, and FDTD models calculated with different finite-difference cell sizes are compared to find the effect of model discretization on the solution. The discretization errors, calculated as absolute error in ellipticity, are presented for the different ground geometry models considered, and are, for the most part, below 10% of the integral equation solutions. Finally, the FDTD code is used to calculate the magnetic ellipticity response of a 2D survey and a 3D sounding of complicated geophysical targets. The response of these 2D and 3D targets are too complicated to be verified with integral equation solutions, but show the proper low- and high-frequency responses.

  19. INEL cold test pit demonstration of improvements in information derived from non-intrusive geophysical methods over buried waste sites

    International Nuclear Information System (INIS)

    1994-01-01

    Under contract between US DOE Idaho National Engineering Laboratory (INEL) and the Blackhawk Geosciences Division of Coleman Research Corporation (BGD-CRC), geophysical investigations were conducted to improve the detection of buried wastes. Over the Cold Test Pit (CTP) at INEL, data were acquired with multiple sensors on a dense grid. Over the CTP the interpretations inferred from geophysical data are compared with the known placement of various waste forms in the pit. The geophysical sensors employed were magnetics, frequency and time domain electromagnetics, and ground penetrating radar. Also, because of the high data density acquired, filtering and other data processing and imaging techniques were tested. After completion and analysis of the survey and interpretation over the CTP, the second phase of investigation consisted of testing geophysical methods over the Idaho Chemical Processing Plant (ICPP). The sections of the ICPP surveyed are underlain by a complex network of buried utility lines of different dimensions and composition, and with placement at various depths up to 13 ft. Further complications included many metallic objects at the surface, such as buildings, reinforced concrete pads, and debris. Although the multiple geophysical sensor approach mapped many buried utilities, they mapped far from all utilities shown on the facility drawings. This report consists of data collected from these geophysical surveys over the ICPP

  20. Analysis of shallow continuous electromagnetic measurements on archaeological sites in southern Austria and comparison with other geophysical methods

    Science.gov (United States)

    Niesner, Erich

    2010-05-01

    Aim of this investigation was outlining the potential of continuous electromagnetic measurements by the comparison of the electromagnetic results with other different geophysical methods at known archaeological sites in Carinthia (Southern Austria). In general a very high resolution is necessary to outline the foundations of roman buildings covered by a sedimentary layer of at least half a meter thickness. The electromagnetic prospecting method had been applied within an archaeologically important region, the archaeological remnants of the first roman provincial capital at the Magdalensberg and at the site of the later location of the capital, at Virunum. With the establishment and consolidation of the Roman Empire the Romans needed more settlement space for the fast growing town and also the demands for defence were less - therefore the Romans transferred the provincial capital down to the "Zollfeld" valley northeast of Klagenfurt. Additional to the electromagnetic investigations, geoelectric, magnetic and susceptibility mapping, spontaneous potential surveys, multielectrode tomography (Niesner, Scholger, Leonhardt 2009) and ground penetrating radar (Morawetz 2006) have been employed jointly during the last years. Also visual and infrared aerial pictures had been available from those areas. The work had been done within a collaborative project between the Geophysical Institute of the University of Leoben and the Landesmuseum Kärnten. The fieldwork and part of the interpretation had been done by students of the University of Leoben within summer field camps. Within these surveys various portions of the archaeological sites had been mapped, providing valuable information of this ancient settlement. One of the most important achievements of the past years of close integration work by the archaeological and the geophysical team was the detailed outlining of an early Christian church, dated by the archaeologists to the early time of the Christians (Dolenz, Niesner

  1. 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

  2. The hydrocarbon accumulations mapping in crystalline rocks by mobile geophysical methods

    Science.gov (United States)

    Nesterenko, A.

    2013-05-01

    Sedimentary-migration origin theory of hydrocarbons dominates nowadays. However, a significant amount of hydrocarbon deposits were discovered in the crystalline rocks, which corroborates the theory of non-organic origin of hydrocarbons. During the solving of problems of oil and gas exploration in crystalline rocks and arrays so-called "direct" methods can be used. These methods include geoelectric methods of forming short-pulsed electromagnetic field (FSPEF) and vertical electric-resonance sounding (VERS) (FSPEF-VERS express-technology). Use of remote Earth sounding (RES) methods is also actual. These mobile technologies are extensively used during the exploration of hydrocarbon accumulations in crystalline rocks, including those within the Ukrainian crystalline shield. The results of explorations Four anomalous geoelectric zones of "gas condensate reservoir" type were quickly revealed as a result of reconnaissance prospecting works (Fig. 1). DTA "Obukhovychi". Anomaly was traced over a distance of 4 km. Approximate area is 12.0 km2. DTA"Korolevskaya". Preliminary established size of anomalous zone is 10.0 km2. The anomalous polarized layers of gas and gas-condensate type were determined. DTA "Olizarovskaya". Approximate size of anomaly is about 56.0 km2. This anomaly is the largest and the most intense. DTA "Druzhba". Preliminary estimated size of anomaly is 16.0 km2. Conclusions Long experience of a successful application of non-classical geoelectric methods for the solving of variety of practical tasks allow one to state their contribution to the development of a new paradigm of geophysical researches. Simultaneous usage of the remote sensing data processing and interpretation method and FSPEF and VERS technologies can essentially optimize and speed up geophysical work. References 1. S.P. Levashov. Detection and mapping of anomalies of "hydrocarbon deposit" type in the fault zones of crystalline arrays by geoelectric methods. / S.P. Levashov, N.A. Yakymchuk, I

  3. 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.

  4. Geophysical experiments at Mariano Lake uranium orebody

    International Nuclear Information System (INIS)

    Thompson, D.T.

    1980-01-01

    Several geophysical experiments were performed over the Mariano Lake orebody before mining. Surface self-potential methods, surface-to-hole induced-polarization methods, and reflection-seismic methods were used. These geophysical techniques provided data which relate to the conceptual model of this orebody. Currents generated in the productive formation by oxidation-reduction reactions do not generate measurable potential anomalies at the surface. Surface-to-hole induced-polarization measurements apparently can detect an oxidation-reduction front in the vicinity of an exploration borehole. Reflection-seismic techniques can provide information concening the paleostructure of the area

  5. Final disposal of spent nuclear fuel-geological, hydrogeological and geophysical methods for site characterization

    International Nuclear Information System (INIS)

    Ahlbom, K.; Carlsson, L.; Olsson, O.

    1983-05-01

    Investigations for the siting of a final repository for high-level radioactive waste are currently being conducted in crystalline rock formations in Sweden. A repository will be located at a depth of about 500 m, and investigations are being carried out in drill holes to below that level. A standard program has been established for the site investigations, comprising a number of phases: 1. General reconnaissance for selection of study site 2. Detailed investigation on the ground surface 3. Depth investigation in drill holes 4. Evaluation and modelling 1. Includes geological and geophysical reconnaissance measurements and drilling of one deep drill hole 2. includes surface and depth investigation within an area of approximately 4-8 km 2 . The surface investigations consist of geophysical measurements including electrical resistivity, magnetization, induced polarization and seismic measurements, and yeild informatin on the composition and fracturing of the bedrock in the superficial parts of the study sites. Mapping of the superficial parts of the bedrock are concluded with short percussion and core drillholes down to 150-250 metres in order to determine the dip and character of fracture zones and rock boundaries. 3. Comprises core drilling to vertical depths of about 600 m, core mapping geophysical well-logging and different hydraulic downhole measurements. In core mapping, the emphasis is placed on fracture characterization of the core. The geophysical logging includes three resistivity methods, natural gamma, induced polarization, spontaneous potential and temperature, salinity, pH and Eh of the drill hole fluid. The hydraulic measurements include: measurements of hydraulic conductivity by single-hole and cross-hole testing, determination of the hydraulic fracture frequency and determination of groundwater head at different levels in the bedrock. (G.B.)

  6. 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.

  7. Groundwater geophysics. A tool for hydrology. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Kirsch, Reinhard (ed.) [Landesamt fuer Natur und Umwelt, Flintbek (Germany). Abt. Geologie/Boden

    2009-07-01

    Access to clean water is a human right and a basic requirement for economic development. The safest kind of water supply is the use of groundwater. Since groundwater normally has a natural protection against pollution by the covering layers, only minor water treatment is required. Detailed knowledge on the extent, hydraulic properties, and vulnerability of groundwater reservoirs is necessary to enable a sustainable use of the resources. This book addresses students and professionals in Geophysics and Hydrogeology. The aim of the authors is to demonstrate the application of geophysical techniques to provide a database for hydrogeological decisions like drillhole positioning or action plans for groundwater protection. Physical fundamentals and technical aspects of modern geophysical reconnaissance methods are discussed in the first part of the book. Beside 'classical' techniques like seismic, resistivity methods, radar, magnetic, and gravity methods emphasis is on relatively new techniques like complex geoelectric, radiomagnetotellurics, vertical groundwater flow determination, or nuclear magnetic resonance. An overview of direct push techniques is given which can fill the gap between surface and borehole geophysics. The applications of these techniques for hydrogeological purposes are illustrated in the second part of the book. The investigation of pore aquifers is demonstrated by case histories from Denmark, Germany, and Egypt. Examples for the mapping of fracture zone and karst aquifers as well as for saltwater intrusions leading to reduced groundwater quality are shown. The assessment of hydraulic conductivities of aquifers by geophysical techniques is discussed with respect to the use of porosity - hydraulic conductivity relations and to geophysical techniques like NMR or SIP which are sensitive to the effective porosity of the material. The classification of groundwater protective layers for vulnerability maps as required by the EU water framework

  8. 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.)

  9. Description of geophysical data in the SKB database GEOTAB

    International Nuclear Information System (INIS)

    Sehlstedt, S.

    1988-02-01

    For the storage of different types of data collected by SKB a database called Geotab has been created. The following data are stored in the database: Background data, geological data, geophysical data, hydrogeological data, hydrochemical data. This report describes the data flow for different types of geophysical measurements. The descriptions start with measurements and end with the storage of data in Geotab. Each process and the resulting data volume is presented separately. The geophysical measurements have been divided into the following subjects: Geophysical ground surface measurements, profile measurements; geophysical ground surface measurements, grid net measurements; geophysical borehole logging; petrophysical measurements. Each group of measurements is described in an individual chapter. In each chapter several measuring techniques are described and each method has a data table and a flyleaf table in Geotab. (orig.)

  10. 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

  11. 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

  12. Landslides Monitoring on Salt Deposits Using Geophysical Methods, Case study - Slanic Prahova, Romania

    Science.gov (United States)

    Ovidiu, Avram; Rusu, Emil; Maftei, Raluca-Mihaela; Ulmeanu, Antonio; Scutelnicu, Ioan; Filipciuc, Constantina; Tudor, Elena

    2017-12-01

    Electrometry is most frequently applied geophysical method to examine dynamical phenomena related to the massive salt presence due to resistivity contrasts between salt, salt breccia and geological covering formations. On the vertical resistivity sections obtained with VES devices these three compartments are clearly differentiates by high resistivity for the massive salt, very low for salt breccia and variable for geological covering formations. When the land surface is inclined, shallow formations are moving gravitationally on the salt back, producing a landslide. Landslide monitoring involves repeated periodically measurements of geoelectrical profiles into a grid covering the slippery surface, in the same conditions (climate, electrodes position, instrument and measurement parameters). The purpose of monitoring landslides in Slanic Prahova area, was to detect the changes in resistivity distribution profiles to superior part of subsoil measured in 2014 and 2015. Measurement grid include several representative cross sections in susceptibility to landslides point of view. The results are graphically represented by changing the distribution of topography and resistivity differences between the two sets of geophysical measurements.

  13. Fundamentals of Geophysics

    Science.gov (United States)

    Lowrie, William

    1997-10-01

    This unique textbook presents a comprehensive overview of the fundamental principles of geophysics. Unlike most geophysics textbooks, it combines both the applied and theoretical aspects to the subject. The author explains complex geophysical concepts using abundant diagrams, a simplified mathematical treatment, and easy-to-follow equations. After placing the Earth in the context of the solar system, he describes each major branch of geophysics: gravitation, seismology, dating, thermal and electrical properties, geomagnetism, paleomagnetism and geodynamics. Each chapter begins with a summary of the basic physical principles, and a brief account of each topic's historical evolution. The book will satisfy the needs of intermediate-level earth science students from a variety of backgrounds, while at the same time preparing geophysics majors for continued study at a higher level.

  14. Integrating Multiple Geophysical Methods to Quantify Alpine Groundwater- Surface Water Interactions: Cordillera Blanca, Peru

    Science.gov (United States)

    Glas, R. L.; Lautz, L.; McKenzie, J. M.; Baker, E. A.; Somers, L. D.; Aubry-Wake, C.; Wigmore, O.; Mark, B. G.; Moucha, R.

    2016-12-01

    Groundwater- surface water interactions in alpine catchments are often poorly understood as groundwater and hydrologic data are difficult to acquire in these remote areas. The Cordillera Blanca of Peru is a region where dry-season water supply is increasingly stressed due to the accelerated melting of glaciers throughout the range, affecting millions of people country-wide. The alpine valleys of the Cordillera Blanca have shown potential for significant groundwater storage and discharge to valley streams, which could buffer the dry-season variability of streamflow throughout the watershed as glaciers continue to recede. Known as pampas, the clay-rich, low-relief valley bottoms are interfingered with talus deposits, providing a likely pathway for groundwater recharged at the valley edges to be stored and slowly released to the stream throughout the year by springs. Multiple geophysical methods were used to determine areas of groundwater recharge and discharge as well as aquifer geometry of the pampa system. Seismic refraction tomography, vertical electrical sounding (VES), electrical resistivity tomography (ERT), and horizontal-to-vertical spectral ratio (HVSR) seismic methods were used to determine the physical properties of the unconsolidated valley sediments, the depth to saturation, and the depth to bedrock for a representative section of the Quilcayhuanca Valley in the Cordillera Blanca. Depth to saturation and lithological boundaries were constrained by comparing geophysical results to continuous records of water levels and sediment core logs from a network of seven piezometers installed to depths of up to 6 m. Preliminary results show an average depth to bedrock for the study area of 25 m, which varies spatially along with water table depths across the valley. The conceptual model of groundwater flow and storage derived from these geophysical data will be used to inform future groundwater flow models of the area, allowing for the prediction of groundwater

  15. Analysis of the applicability of geophysical methods and computer modelling in determining groundwater level

    Science.gov (United States)

    Czaja, Klaudia; Matula, Rafal

    2014-05-01

    The paper presents analysis of the possibilities of application geophysical methods to investigation groundwater conditions. In this paper groundwater is defined as liquid water flowing through shallow aquifers. Groundwater conditions are described through the distribution of permeable layers (like sand, gravel, fractured rock) and impermeable or low-permeable layers (like clay, till, solid rock) in the subsurface. GPR (Ground Penetrating Radar), ERT(Electrical Resistivity Tomography), VES (Vertical Electric Soundings) and seismic reflection, refraction and MASW (Multichannel Analysis of Surface Waves) belong to non - invasive, surface, geophysical methods. Due to differences in physical parameters like dielectric constant, resistivity, density and elastic properties for saturated and saturated zones it is possible to use geophysical techniques for groundwater investigations. Few programmes for GPR, ERT, VES and seismic modelling were applied in order to verify and compare results. Models differ in values of physical parameters such as dielectric constant, electrical conductivity, P and S-wave velocity and the density, layers thickness and the depth of occurrence of the groundwater level. Obtained results for computer modelling for GPR and seismic methods and interpretation of test field measurements are presented. In all of this methods vertical resolution is the most important issue in groundwater investigations. This require proper measurement methodology e.g. antennas with frequencies high enough, Wenner array in electrical surveys, proper geometry for seismic studies. Seismic velocities of unconsolidated rocks like sand and gravel are strongly influenced by porosity and water saturation. No influence of water saturation degree on seismic velocities is observed below a value of about 90% water saturation. A further saturation increase leads to a strong increase of P-wave velocity and a slight decrease of S-wave velocity. But in case of few models only the

  16. Use of geophysical methods to characterize groundwater in karstic rocks near Puerto Morelos, Yucatan Peninsula, Mexico

    Science.gov (United States)

    cerda Garcia, C. G.; Carpenter, P. J.; Leal-Bautista, R. M.

    2017-12-01

    Geophysical surveys were used to determine the depth of the freshwater/saltwater interface and groundwater preferential flow pathways along the Ruta de los Cenotes, near Puerto Morelos (northeast part of the Yucatán peninsula). The Yucatán Peninsula is a limestone platform that allows quick recharge of the aquifer, the main supply of water for this region. The water in the aquifer is divided into freshwater and saltwater zones. A Schlumberger resistivity sounding along the road near one cenote suggests the water table is 5 meters deep and the freshwater/saltwater interface is 38 meters deep. A time-domain electromagnetic (TEM) sounding suggests the freshwater/saltwater interface is 45 meters deep. The depth of the interface determines the volume of fresh water available. Preferential flow pathways in the vadose and saturated zones are karst conduits where groundwater percolates downward in the vadose zone. These were identified using resistivity profiling and spontaneous self-potential (SP) geophysical methods. Interpretation of SP profile Line SP1, located 3 m south of the cenote, suggests two fractures, which appear to extend south as far as SP profile Line SP2, 15 m south of the cenote; both lines are parallel to each other. SP anomalies suggest water flow along these fractures. The use of noninvasive geophysical methods, specifically SP, resistivity and TEM are useful for exploring the karst system in the Yucatán peninsula.

  17. 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

  18. Geophysical and geochemical techniques for exploration of hydrocarbons and minerals

    International Nuclear Information System (INIS)

    Sittig, M.

    1980-01-01

    The detailed descriptive information in this book is based on 389 US patents that deal with geophysical and geochemical techniques useful for the exploration of hydrocarbons and minerals. Where it was necessary to round out the complete technological picture, a few paragraphs from cited government reports have been included. These techniques are used in prospecting for oil, coal, oil shale, tar sand and minerals. The patents are grouped under the following chapters: geochemical prospecting; geobiological prospecting; geophysical exploration; magnetic geophysical prospecting; gravitational geophysical prospecting; electrical geophysical prospecting; nuclear geophysical prospecting; seismic geophysical prospecting; and exploratory well drilling. This book serves a double purpose in that it supplies detailed technical information and can be used as a guide to the US patent literature in this field. By indicating all the information that is significant, and eliminating legal jargon and juristic phraseology, this book presents an advanced, industrially oriented review of modern methods of geophysical and geochemical exploration techniques

  19. Mobile geophysics for searching and exploration of Domanic hydrocarbon deposits

    Science.gov (United States)

    Borovsky, M. Ya; Uspensky, B. V.; Valeeva, S. E.; Borisov, A. S.

    2018-05-01

    There are noted features of shale hydrocarbons occurrence. It is shown the role of geophysical prospecting in the geological prospecting process for non-traditional sources of hydrocarbon. There are considered the possibilities of non-seismic methods for forecasting, prospecting, exploration and preparation of Domanikovian hydrocarbons accumulations for exploration. It is emphasized the need for geophysical studies of tectonic disturbances. Modern aerogeophysical instrumentation and methodological support allows to combine high-precision magneto-prospecting with gravimetric and gamma spectrometry. This combination of geophysical methods contributes to the diagnosis of active and latent faults.

  20. New method for determining free core nutation parameters, considering geophysical effects

    Science.gov (United States)

    Vondrák, J.; Ron, C.

    2017-08-01

    Context. In addition to the torques exerted by the Moon, Sun, and planets, changes of precession-nutation are known to be caused also by geophysical excitations. Recently studies suggest that geomagnetic jerks (GMJ) might be associated with sudden changes of phase and amplitude of free core nutation. We showed that using atmospheric and oceanic excitations with those by GMJ improves substantially the agreement with observed celestial pole offsets. Aims: Traditionally, the period Tf and quality factor Qf of the free core nutation (FCN) are derived from VLBI-based celestial pole offsets (CPO). Either direct analysis of the observed CPO, or indirect method using resonant effects of nutation terms with frequencies close to FCN, are used. The latter method is usually preferred, since it yields more accurate results. Our aim is to combine both approaches to better derive FCN parameters. Methods: We numerically integrated the part of CPO that is due to geophysical excitations for different combinations of Tf, Qf, using Brzeziński's broadband Liouville equations (Brzeziński 1994, Manuscripta geodaetica, 19, 157), and compared the results with the observed values of CPO. The values yielding the best fit were then estimated. The observed CPO, however, must be corrected for the change of nutation that is caused by the Tf, Qf values different from those used to calculate IAU 2000 model of nutation. To this end, we have used the Mathews-Herring-Buffet transfer function and applied it to the five most affected terms of nutation (with periods 365.26, 182.62, 121.75, 27.55 and 13.66 days). Results: The results, based on the CPO data in the interval 1986.0—2016.0 and excitations with three different models, are presented. We demonstrate that better results are obtained if the influence of additional excitations at GMJ epochs is added to excitations by the atmosphere and oceans. Our preferred values are Tf = 430.28 ± 0.04 mean solar days and Qf = 19 500 ± 200.

  1. 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.

  2. Geophysical methods applied to detection delineation and evaluation of geothermal resources, Snowbird, Utah, August 24--28, 1975

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    A report is given on the geothermal workshop devoted to inventorying current knowledge, problems, controversies, and predicting future developments in the application of geophysical methods to the evaluation of geothermal resources. Separate abstracts were prepared for presentations and summaries of the group sessions. (LBS)

  3. Technical Note: Calibration and validation of geophysical observation models

    NARCIS (Netherlands)

    Salama, M.S.; van der Velde, R.; van der Woerd, H.J.; Kromkamp, J.C.; Philippart, C.J.M.; Joseph, A.T.; O'Neill, P.E.; Lang, R.H.; Gish, T.; Werdell, P.J.; Su, Z.

    2012-01-01

    We present a method to calibrate and validate observational models that interrelate remotely sensed energy fluxes to geophysical variables of land and water surfaces. Coincident sets of remote sensing observation of visible and microwave radiations and geophysical data are assembled and subdivided

  4. A multi-method high-resolution geophysical survey in the Machado de Castro museum, central Portugal

    International Nuclear Information System (INIS)

    Grangeia, Carlos; Matias, Manuel; Hermozilha, Hélder; Figueiredo, Fernando; Carvalho, Pedro; Silva, Ricardo

    2011-01-01

    Restoration of historical buildings is a delicate operation as they are often built over more ancient and important structures. The Machado de Castro Museum, Coimbra, Central Portugal, has suffered several interventions in historical times and lies over the ancient Roman forum of Coimbra. This building went through a restoration project. These works were preceded by an extensive geophysical survey that aimed at investigating subsurface stratigraphy, including archeological remains, and the internal structure of the actual walls. Owing to the needs of the project, geophysical data interpretation required not only integration but also high resolution. The study consisted of data acquisition over perpendicular planes and different levels that required detailed survey planning and integration of data from different locations that complement images of the surveyed area. Therefore a multi-method, resistivity imaging and a 3D ground probing radar (GPR), high-resolution geophysical survey was done inside the museum. Herein, radargrams are compared with the revealed stratigraphy so that signatures are interpreted, characterized and assigned to archeological structures. Although resistivity and GPR have different resolution capabilities, their data are overlapped and compared, bearing in mind the specific characteristics of this survey. It was also possible to unravel the inner structure of the actual walls, to establish connections between walls, foundations and to find older remains with the combined use and spatial integration of the GPR and resistivity imaging data

  5. Sustainable urban development and geophysics

    Science.gov (United States)

    Liu, Lanbo; Chan, L. S.

    2007-09-01

    investigated [2]. The first objective of urban geophysics is to study systematically the geophysical fields in cities, searching for principles and processes governing the intensity and patterns of variation of the geophysical properties, as well as the potential consequences on the biosphere. Secondly, geophysics has already been found to be a useful tool for subsurface detection and investigation, hazard mitigation, and assessment of environmental contamination. Geophysicists have documented numerous cases of successful applications of geophysical techniques to solve problems related to hazard mitigation, safeguarding of lifeline infrastructure and urban gateways (air- and sea-ports, railway and highway terminals), archaeological and heritage surveys, homeland security, urban noise control, water supplies, sanitation and solid waste management etc. In contrast to conventional geophysical exploration, the undertaking of geophysical surveys in an urban setting faces many new challenges and difficulties. First of all, the ambient cultural noise in cities caused by traffic, electromagnetic radiation and electrical currents often produce undesirably strong interference with geophysical measurements. Secondly, subsurface surveys in an urban area are often targeted at the uppermost several metres of the ground, which are the most heterogeneous layers with many man-made objects. Thirdly, unlike conventional geophysical exploration which requires resolution in the order of metres, many urban geophysical surveys demand a resolution and precision in the order of centimetres or even millimetres. Finally restricted site access and limited time for conducting geophysical surveys, regulatory constraints, requirements for traffic management and special logistical arrangements impose additional difficulties. All of these factors point to the need for developing innovative research methods and geophysical instruments suitable for use in urban settings. This special issue on 'Sustainable urban

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

    Science.gov (United States)

    Eppelbaum, L. V.

    2012-04-01

    The Caucasian Mountains occupy an area of about 440,000 km2. A number of important mineral resources are concentrated there. Geophysical data on the geological structure of Caucasus can shed light on the basic principles of evolution of the Earth, the distribution of minerals and seismic activity. However, geophysical surveys under complex conditions are generally riddled by poor accessibility to certain mountainous regions, the unevenness of observation surfaces, as well as by a great variety and frequent changes of tectonic structures and geological bodies with variable physical properties. These factors either restrict geophysical surveys in difficult environments or confine the scope of useful information drawn from the results obtained. This has led to the development of special techniques in geophysical surveys, data processing and interpretation that draws heavily on the experience accumulated in the specific conditions of these mountainous regions. First applied geophysical observations in the Caucasus region - thermal measurements in boreholes - were carried out by Bazevich (1881) in the Absheron Peninsula. At the same time, start of the initial stage is usually referred to as the mid 20-s of the XX century, when the rare, but systematic geophysical observations (mainly gravity and magnetic) were begun in some Caucasian areas. Somewhat later began to apply the resistivity method. Mid 30-s is characterized by the beginning of application of borehole geophysics and seismic prospecting. The marine seismics firstly in the former Soviet Union was tested in the Caspian Sea. In general, the initial stage is characterized by slow, but steady rise (except during World War II) lasted until 1960. A basic stage (1960-1991) is characterized by very intensive employment of geophysical methods (apparently, any possible geophysical methods were tested in this region). At this time the Caucasus region is considered in the former Soviet Union as a geophysical polygon for

  7. East Chestnut Ridge hydrogeologic characterization: A geophysical study of two karst features

    International Nuclear Information System (INIS)

    1991-01-01

    Permitting and site selection activities for the proposed East Chestnut Ridge landfill, located on the Oak Ridge Reservation, have required additional hydrogeologic studies of two karst features. Geophysical testing methods were utilized for investigating these karst features. The objectives of the geophysical testing was to determine the feasibility of geophysical techniques for locating subsurface karst features and to determine if subsurface anomalies exist at the proposed landfill site. Two karst features, one lacking surface expression (sinkhole) but with a known solution cavity at depth (from previous hydrologic studies), and the other with surface expression were tested with surface geophysical methods. Four geophysical profiles, two crossing and centered over each karst feature were collected using both gravimetric and electrical resistivity techniques

  8. Geological modeling and infiltration pattern of a karstic system based upon crossed geophysical methods and image-guided inversion

    Science.gov (United States)

    Duran, Lea; Jardani, Abderrahim; Fournier, Matthieu; Massei, Nicolas

    2015-04-01

    Karstic aquifers represent an important part of the water resources worldwide. Though they have been widely studied on many aspects, their geological and hydrogeological modeling is still complex. Geophysical methods can provide useful subsurface information for the characterization and mapping of karstic systems, especially when not accessible by speleology. The site investigated in this study is a sinkhole-spring system, with small diameter conduits that run within a chalk aquifer (Norville, in Upper Normandy, France). This site was investigated using several geophysical methods: electrical tomography, self-potential, mise-à-la-masse methods, and electromagnetic method (EM34). Coupling those results with boreholes data, a 3D geological model of the hydrogeological basin was established, including tectonic features as well as infiltration structures (sinkhole, covered dolines). The direction of the karstic conduits near the main sinkhole could be established, and the major fault was shown to be a hydraulic barrier. Also the average concentration of dolines on the basin could be estimated, as well as their depth. At last, several hypotheses could be made concerning the location of the main conduit network between the sinkhole and the spring, using previous hydrodynamic study of the site along with geophysical data. In order to validate the 3D geological model, an image-guided inversion of the apparent resistivity data was used. With this approach it is possible to use geological cross sections to constrain the inversion of apparent resistivity data, preserving both discontinuities and coherences in the inversion of the resistivity data. This method was used on the major fault, enabling to choose one geological interpretation over another (fault block structure near the fault, rather than important folding). The constrained inversion was also applied on covered dolines, to validate the interpretation of their shape and depth. Key words: Magnetic and electrical

  9. Comprehensive geophysical and geochemical method and prognosis criteria for the exploration of unconformity type uranium deposit in Russia

    International Nuclear Information System (INIS)

    Li Mao; Chen Zuyi

    2007-01-01

    According to the transcripts of the lectures by Russian experts during the investigation and training in Russia, the comprehensive geophysical and geochemical method and the prognosis criteria of Russia's unconformity type uranium deposit exploration are introduced in the paper. (authors)

  10. Methods to evaluate some reservoir characterization by means of the geophysical data in the strata of limestone and marl

    Directory of Open Access Journals (Sweden)

    V. M. Seidov

    2017-12-01

    Full Text Available As we know, the main goal of interpreting the materials of well logging, including the allocation of collectors and assessment of their saturation, are successfully achieved when the process of interpretation has a strong methodological support. This means, that it is justified by the necessary interpretational models and effective instructional techniques are used. They are based on structural and petrophysical models of reservoirs of the section investigated. The problem of studying the marl rocks with the help of the geophysical methods is not worked out properly. Many years of experience of studying limestone and marl rocks has made it possible to justify the optimal method of data interpretation of geophysical research wells in carbonate sections, which was represented by limestone and marl formations. A new method was developed to study marl rocks. It includes the following main studies: detection of reservoirs in the carbonate section according to the materials of geophysical studies of wells; determination of the geophysical parameters of each reservoir; assessment of the quality of well logging curves; introduction of amendments; selection of reference layers; the calculation of the relative double differencing parameters; the involvement of core data; identifying the lithological rock composition; the rationale for structural models of reservoirs; the definition of the block and of the total porosity; determination of argillaceous carbonate rocks; determination of the coefficient of water saturation of formations based on the type of the collector; setting a critical value for effective porosity, etc. This method was applied in the Eocene deposits of the Interfluve of the Kura and Iori, which is a promising object of hydrocarbons in Azerbaijan. The following conclusions have been made: this methodology successfully solves the problem of petrophysical characteristics of marl rocks; bad connection is observed between some of the

  11. Modeling geophysical complexity: a case for geometric determinism

    Directory of Open Access Journals (Sweden)

    C. E. Puente

    2007-01-01

    Full Text Available It has been customary in the last few decades to employ stochastic models to represent complex data sets encountered in geophysics, particularly in hydrology. This article reviews a deterministic geometric procedure to data modeling, one that represents whole data sets as derived distributions of simple multifractal measures via fractal functions. It is shown how such a procedure may lead to faithful holistic representations of existing geophysical data sets that, while complementing existing representations via stochastic methods, may also provide a compact language for geophysical complexity. The implications of these ideas, both scientific and philosophical, are stressed.

  12. Some case studies of geophysical exploration of archaeological sites in Yugoslavia

    Science.gov (United States)

    Komatina, Snezana; Timotijevic, Zoran

    1999-03-01

    One of the youngest branches of environmental geophysics application is the preservation of national heritage. Numerous digital techniques developed for exploration directed to urban planning can also be applied to investigations of historic buildings. In identifying near-surface layers containing objects of previous civilizations, various sophisticated geophysical methods are used. In the paper, application of geophysics in quantification of possible problems necessary to be carried out in order to get an archaeological map of some locality is discussed [Komatina, S., 1996]. Sophisticated geophysical methods in the preservation of national heritage. Proc. of Int. Conf. Architecture and Urbanism at the turn of the Millenium, Beograd, pp. 39-44. Finally, several examples of archaeogeophysical exploration at Divostin, Bedem and Kalenic monastery localities (Serbia, Yugoslavia) are presented.

  13. New significance test methods for Fourier analysis of geophysical time series

    Directory of Open Access Journals (Sweden)

    Z. Zhang

    2011-09-01

    Full Text Available When one applies the discrete Fourier transform to analyze finite-length time series, discontinuities at the data boundaries will distort its Fourier power spectrum. In this paper, based on a rigid statistics framework, we present a new significance test method which can extract the intrinsic feature of a geophysical time series very well. We show the difference in significance level compared with traditional Fourier tests by analyzing the Arctic Oscillation (AO and the Nino3.4 time series. In the AO, we find significant peaks at about 2.8, 4.3, and 5.7 yr periods and in Nino3.4 at about 12 yr period in tests against red noise. These peaks are not significant in traditional tests.

  14. Potential shallow aquifers characterization through an integrated geophysical method: multivariate approach by means of k-means algorithms

    Directory of Open Access Journals (Sweden)

    Stefano Bernardinetti

    2017-06-01

    Full Text Available The need to obtain a detailed hydrogeological characterization of the subsurface and its interpretation for the groundwater resources management, often requires to apply several and complementary geophysical methods. The goal of the approach in this paper is to provide a unique model of the aquifer by synthesizing and optimizing the information provided by several geophysical methods. This approach greatly reduces the degree of uncertainty and subjectivity of the interpretation by exploiting the different physical and mechanic characteristics of the aquifer. The studied area, into the municipality of Laterina (Arezzo, Italy, is a shallow basin filled by lacustrine and alluvial deposits (Pleistocene and Olocene epochs, Quaternary period, with alternated silt, sand with variable content of gravel and clay where the bottom is represented by arenaceous-pelitic rocks (Mt. Cervarola Unit, Tuscan Domain, Miocene epoch. This shallow basin constitutes the unconfined superficial aquifer to be exploited in the nearly future. To improve the geological model obtained from a detailed geological survey we performed electrical resistivity and P wave refraction tomographies along the same line in order to obtain different, independent and integrable data sets. For the seismic data also the reflected events have been processed, a remarkable contribution to draw the geologic setting. Through the k-means algorithm, we perform a cluster analysis for the bivariate data set to individuate relationships between the two sets of variables. This algorithm allows to individuate clusters with the aim of minimizing the dissimilarity within each cluster and maximizing it among different clusters of the bivariate data set. The optimal number of clusters “K”, corresponding to the individuated geophysical facies, depends to the multivariate data set distribution and in this work is estimated with the Silhouettes. The result is an integrated tomography that shows a finite

  15. 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

  16. A New Alternative in Urban Geophysics: Multi-Channel Analysis of Surface Waves (MASW) Method

    International Nuclear Information System (INIS)

    Ozcep, F.

    2007-01-01

    Geophysical studies are increasingly being applied to geotechnical investigations as they can identify soil properties and soil boundaries. Other advantage is that many of these methods are non-invasive and environment friendly. Soil stiffness is one of the critical material parameters considered during an early stage of most foundation construction. It is related directly to the stability of structural load, especially as it relates to possible earthquake hazard. Soil lacking sufficient stiffness for a given load can experience a significant reduction in strength under earthquake shaking resulting in liquefaction, a condition responsible for tremendous amounts of damage from earthquakes around the world The multichannel analysis of surface waves (MASW) method originated from the traditional seismic exploration approach that employs multiple (twelve or more) receivers placed along a linear survey line. Main advantage is its capability of recognizing different types of seismic waves based on wave propagation characteristics such as velocity and attenuation. The MASW method utilizes this capability to discriminate the fundamental-mode Rayleigh wave against all other types of surface and body waves generated not only from the active seismic source but also from the ambient site conditions. Dispersive characteristics of seismic waves are imaged from an objective 2-D wave field transformation. The present paper indicates results from MASW survey at different urban site in Turkey. MASW techniques will prove to be important tools for obtaining shear wave velocity and evaluating liquefaction potential, soil bearing capacity and soil amplification, etc. for future geophysical and geotechnical engineering community

  17. Application of comprehensive geophysical methods to prospecting for sandstone-type uranium deposit in Bayanmaodu basin

    International Nuclear Information System (INIS)

    Yao Yifeng; Sun Zexuan; Chen Zhiguo; He Tao; Li Guoxin

    2003-01-01

    By using comprehensive geophysical methods including magnetic survey, resistivity sounding, self potential survey, 210 Po survey etc., the shape and the depth of the basement, the structure of the sedimentary cover, characteristics of prospecting target horizon, the development of interlayer oxidation zone at depth, as well as the information of uranium mineralization have been basically revealed, thus providing a basis for the prospect evaluation of sandstone-type uranium mineralization in the basin

  18. Brief overview of geophysical probing technology

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Lytle, R.J.

    1982-01-01

    An evaluation of high-resolution geophysical techniques which can be used to characterize a nulcear waste disposal site is being conducted by the Lawrence Livermore National Laboratory (LLNL) at the request of the US Nuclear Regulatory Commisson (NRC). LLNL is involved in research work aimed at evaluating the current capabilities and limitations of geophysical methods used for site selection. This report provides a brief overview of the capabilities and limitations associated with this technology and explains how our work addresses some of the present limitations. We are examining both seismic and electromagnetic techniques to obtain high-resolution information. We are also assessing the usefulness of geotomography in mapping fracture zones remotely. Finally, we are collecting core samples from a site in an effort to assess the capability of correlating such geophysical data with parameters of interest such as fracture continuity, orientation, and fracture density

  19. Environmental geophysics and geochemistry for contamination mapping and monitoring 1

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tai Sup; Lee, Sang Kyu; Hong, Young Kook [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of); and others

    1995-12-01

    This study aims to provide the technologies which can be practically used for contamination mapping and monitoring. To accomplish this goal, the geophysical and geochemical expertise and techniques commonly used in the mineral resources exploration are employed. In the first year of the three-year-long project, the purpose of the study is to introduce the optimum methodologies among the geophysical and geochemical techniques to tackle the various cases of environmental contamination. To achieve the purpose, case studies of the developed countries were surveyed and analyzed through the various kinds of literatures. The followings are categorized to be solved by geophysical methods: 1) delineation of water system pollution by acid mine drainage and distributions of waste rocks in the closed mine area, 2) defining boundaries of subsurface contamination due to oil seepage, 3) zoning of sea water intrusion in the seashore or subsurface geology highly containing salt, 4) locating of buried metallic wastes such as pipes and drums which can cause the secondary pollution by corrosion, and 5) outlining of the subsurface area polluted by leachate from the landfill. To experiment the above items, various geophysical methods were applied to the corresponding test sites. From these experiments, the applicabilities of the respective geophysical method were analyzed, and the optimum methods were derived for the various pollution types. Furthermore, electric and electromagnetic surveys data processing software were developed to quantitatively interpret and highly resolve the geology. The environmental assignments which can be solved by geochemical methods include: 1) drainage pollution by coal mine effluents, 2)subsurface contamination of oil-spill, 3) sea water intrusion, 4) dispersion of toxic heavy metallic elements in the metal mines, and 5) radon environmental geochemistry. The appropriate test sites for applying the geochemical methods were selected. (Abstract Truncated)

  20. 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

  1. Adaptive mesh refinement and adjoint methods in geophysics simulations

    Science.gov (United States)

    Burstedde, Carsten

    2013-04-01

    It is an ongoing challenge to increase the resolution that can be achieved by numerical geophysics simulations. This applies to considering sub-kilometer mesh spacings in global-scale mantle convection simulations as well as to using frequencies up to 1 Hz in seismic wave propagation simulations. One central issue is the numerical cost, since for three-dimensional space discretizations, possibly combined with time stepping schemes, a doubling of resolution can lead to an increase in storage requirements and run time by factors between 8 and 16. A related challenge lies in the fact that an increase in resolution also increases the dimensionality of the model space that is needed to fully parametrize the physical properties of the simulated object (a.k.a. earth). Systems that exhibit a multiscale structure in space are candidates for employing adaptive mesh refinement, which varies the resolution locally. An example that we found well suited is the mantle, where plate boundaries and fault zones require a resolution on the km scale, while deeper area can be treated with 50 or 100 km mesh spacings. This approach effectively reduces the number of computational variables by several orders of magnitude. While in this case it is possible to derive the local adaptation pattern from known physical parameters, it is often unclear what are the most suitable criteria for adaptation. We will present the goal-oriented error estimation procedure, where such criteria are derived from an objective functional that represents the observables to be computed most accurately. Even though this approach is well studied, it is rarely used in the geophysics community. A related strategy to make finer resolution manageable is to design methods that automate the inference of model parameters. Tweaking more than a handful of numbers and judging the quality of the simulation by adhoc comparisons to known facts and observations is a tedious task and fundamentally limited by the turnaround times

  2. Geophysical characterisation of the groundwater-surface water interface

    Science.gov (United States)

    McLachlan, P. J.; Chambers, J. E.; Uhlemann, S. S.; Binley, A.

    2017-11-01

    Interactions between groundwater (GW) and surface water (SW) have important implications for water quantity, water quality, and ecological health. The subsurface region proximal to SW bodies, the GW-SW interface, is crucial as it actively regulates the transfer of nutrients, contaminants, and water between GW systems and SW environments. However, geological, hydrological, and biogeochemical heterogeneity in the GW-SW interface makes it difficult to characterise with direct observations. Over the past two decades geophysics has been increasingly used to characterise spatial and temporal variability throughout the GW-SW interface. Geophysics is a powerful tool in evaluating structural heterogeneity, revealing zones of GW discharge, and monitoring hydrological processes. Geophysics should be used alongside traditional hydrological and biogeochemical methods to provide additional information about the subsurface. Further integration of commonly used geophysical techniques, and adoption of emerging techniques, has the potential to improve understanding of the properties and processes of the GW-SW interface, and ultimately the implications for water quality and environmental health.

  3. Site characterization and validation - geophysical single hole logging

    International Nuclear Information System (INIS)

    Andersson, Per

    1989-05-01

    A total of 15 boreholes have been drilled for preliminary characterization of a previously unexplored site at the 360 and 385 m level in the Stripa mine. To adequately described the rock mass in the vicinity of these boreholes, a comprehensive program utilizing a large number of geophysical borehole methods has been carried out in 10 of these boreholes. The specific geophysical character of the rock mass and the major deformed units distinguished in the vicinity of the boreholes are recognized, and in certain cases also correlated between the boreholes. A general conclusion based on the geophysical logging results, made in this report, is that the preliminary predictions made in stage 2, of the site characterization and validation project (Olsson et.al, 1988), are adequate. The results from the geophysical logging can support the four predicted fracture/ fracture zones GHa, GHb, GA and GB whereas the predicted zones GC and GI are hard to confirm from the logging results. (author)

  4. Geophysical background and as-built target characteristics

    International Nuclear Information System (INIS)

    Allen, J.W.

    1994-09-01

    The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) has provided a facility for DOE, other Government agencies, and the private sector to evaluate and document the utility of specific geophysical measurement techniques for detecting and defining cultural and environmental targets. This facility is the Rabbit Valley Geophysics Performance Evaluation Range (GPER). Geophysical surveys prior to the fiscal year (FY) 1994 construction of new test cells showed the primary test area to be relatively homogeneous and free from natural or man-made artifacts, which would generate spurious responses in performance evaluation data. Construction of nine new cell areas in Rabbit Valley was completed in June 1994 and resulted in the emplacement of approximately 150 discrete targets selected for their physical and electrical properties. These targets and their geophysical environment provide a broad range of performance evaluation parameters from ''very easy to detect'' to ''challenging to the most advanced systems.'' Use of nonintrusive investigative techniques represents a significant improvement over intrusive characterization methods, such as drilling or excavation, because there is no danger of exposing personnel to possible hazardous materials and no risk of releasing or spreading contamination through the characterization activity. Nonintrusive geophysical techniques provide the ability to infer near-surface structure and waste characteristics from measurements of physical properties associated with those targets

  5. 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.

  6. Description of geophysical data in the SKB database GEOTAB. Version 2

    International Nuclear Information System (INIS)

    Sehlstedt, S.

    1991-01-01

    For the storage of different types of data collected by SKB a database called GEOTAB has been created. The following data is stored in the database: Background data, geological data, geophysical data, hydrogeological and meteorological data, hydrochemical data, and tracer tests. This report describes the data flow for different types of geophysical measurement. The descriptions start with measurement and end with the storage of data in GEOTAB. Each process and the resulting data volume is presented separately. The geophysical measurements have been divided into the following subjects: Geophysical ground surface measurements, geophysical borehole logging, and petrophysical measurements. Each group of measurements is described in an individual chapter. In each chapter several measuring techniques are described and each method has a data table and a flyleaf table in GEOTAB. (author)

  7. Applied geophysics for civil engineering and mining engineering. 2. rev. and enlarged ed.

    International Nuclear Information System (INIS)

    Militzer, H.; Schoen, J.; Stoetzner, U.

    1986-01-01

    In the process of geological and geotechnical prospecting for the exploration and exploitation of deposits, as well as for engineering structures, the knowledge contributed by geophysics is of significance in order to ensure an objective assessment of geological and geotechnical conditions of a given site, and to promote economic efficiency in the field of civil engineering and mining. For this reason, engineering and mining geophysics has become an important special subject field. The present second edition of the textbook offers enhanced information about practical applications of available methods and measuring techniques, and about the information to be obtained by civil and mining engineers from the geophysical science. The material has been arranged with a view to practice, facilitating an overview over potential applications and efficiencies as well as limits of geophysical methods. The methods are also explained in terms of suitability for the various steps of civil engineering or mining geological activities and studies. A major extension of the first edition's material consists of the chapter on basic principles and aspects of well geophysics for shallow well drilling. (orig./HP) [de

  8. 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

  9. Integrated geophysical surveys for searching of podiform chromite in Albania

    Energy Technology Data Exchange (ETDEWEB)

    Kospiri, Aleksander; Zajmi, Asim [Geophysical and Geochemical Center, Tirana (Albania)

    1995-12-31

    The purpose of this paper is to describe the application of geophysical methods to the search for chromite in Albania. Albania is well known for its chromite resources and ranks third amongst world producers of high-quality chromite. The ultramafic massif of Bulqiza, is the most important chromite bearing one. Surveying a surface of about 120 square kilometers (30% of massifs area) in that massif with integrated geophysical methods a considerable number of targets has been discovered, from which some are already objects under mine activity. In the integrated methods for chromite exploration in Bulqiza ultramafic massif are included: geological, gravity, magnetic and electrical mapping of the scale 1:2000 with survey grids 40x20m, 20x5m. Based on the interpretations of geophysical exploration were projected drilling which led to the discovery of some big ore deposits. (author). 12 refs., 3 figs

  10. History of geophysical studies at the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico

    International Nuclear Information System (INIS)

    Borns, D.J.

    1997-01-01

    A variety of geophysical methods including the spectrum of seismic, electrical, electromagnetic and potential field techniques have supported characterization, monitoring and experimental studies at the Waste Isolation Pilot Plant (WIPP). The geophysical studies have provided significant understanding of the nature of site deformation, tectonics and stability. Geophysical methods have delineated possible brine reservoirs beneath the underground facility and have defined the disturbed rock zone that forms around underground excavations. The role of geophysics in the WIPP project has evolved with the project. The early uses were for site characterization to satisfy site selection criteria or factors. As the regulatory framework for WIPP grew since 1980, the geophysics program supported experimental and field programs such as Salado hydrogeology and underground room systems and excavations. In summary, the major types of issues that geophysical studies addressed for WIPP are: Site Characterization; Castile Brine Reservoirs; Rustler/Dewey Lake Hydrogeology; Salado Hydrogeology; and Excavation Effects. The nature of geophysics programs for WIPP has been to support investigation rather than being the principal investigation itself. The geophysics program has been used to define conceptual models (e.g., the Disturbed Rock Zone-DRZ) or to test conceptual models (e.g., high transmissivity zones in the Rustler Formation). The geophysics program primarily supported larger characterization and experimental programs. Funding was not available for the complete documentation and interpretation. Therefore, a great deal of the geophysics survey information resides in contractor reports

  11. A Bayesian trans-dimensional approach for the fusion of multiple geophysical datasets

    Science.gov (United States)

    JafarGandomi, Arash; Binley, Andrew

    2013-09-01

    We propose a Bayesian fusion approach to integrate multiple geophysical datasets with different coverage and sensitivity. The fusion strategy is based on the capability of various geophysical methods to provide enough resolution to identify either subsurface material parameters or subsurface structure, or both. We focus on electrical resistivity as the target material parameter and electrical resistivity tomography (ERT), electromagnetic induction (EMI), and ground penetrating radar (GPR) as the set of geophysical methods. However, extending the approach to different sets of geophysical parameters and methods is straightforward. Different geophysical datasets are entered into a trans-dimensional Markov chain Monte Carlo (McMC) search-based joint inversion algorithm. The trans-dimensional property of the McMC algorithm allows dynamic parameterisation of the model space, which in turn helps to avoid bias of the post-inversion results towards a particular model. Given that we are attempting to develop an approach that has practical potential, we discretize the subsurface into an array of one-dimensional earth-models. Accordingly, the ERT data that are collected by using two-dimensional acquisition geometry are re-casted to a set of equivalent vertical electric soundings. Different data are inverted either individually or jointly to estimate one-dimensional subsurface models at discrete locations. We use Shannon's information measure to quantify the information obtained from the inversion of different combinations of geophysical datasets. Information from multiple methods is brought together via introducing joint likelihood function and/or constraining the prior information. A Bayesian maximum entropy approach is used for spatial fusion of spatially dispersed estimated one-dimensional models and mapping of the target parameter. We illustrate the approach with a synthetic dataset and then apply it to a field dataset. We show that the proposed fusion strategy is

  12. Geophysics comes of age in oil sands development

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, P. [WorleyParsons Komex, Calgary, AB (Canada); Birch, R.; Parker, D.; Andrews, B. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

    2008-07-01

    This paper discussed geophysical techniques developed for oil sands exploration and production applications in Alberta's oil sands region. Geophysical methods are playing an important role in mine planning, tailings containment, water supply, and land reclamation activities. Geophysics techniques are used to estimate the volume of muskeg that needs to be stripped and stored for future reclamation activities as well as to site muskeg piles and delineate the thickness of clay Clearwater formations overlying Cretaceous oil-bearing sands. 2-D electrical resistivity mapping is used to map river-connected deep bedrock Pleistocene paleovalleys in the region. Geophysical studies are also used to investigate the interiors of dikes and berms as well as to monitor salt migration within tailings piles. Sonic and density logs are used to create synthetic seismograms for mapping the Devonian surface in the region. The new applications included the calculation of bitumen saturation from surface sands and shales; muskeg thickness mapping; and non-intrusive monitoring of leachate plumes. Geophysical techniques included 2-D electrical resistivity imaging; transient electromagnetic (EM) technologies; ground penetrating radar; and high-resolution seismic reflections. Polarization, surface nuclear magnetic resonance and push-probe sensing techniques were also discussed. Techniques were discussed in relation to Alberta's Athabasca oil sands deposits. 4 refs.

  13. Survey of geophysical techniques for site characterization in basalt, salt and tuff

    International Nuclear Information System (INIS)

    Jones, G.M.; Blackey, M.E.; Rice, J.E.; Murphy, V.J.; Levine, E.N.; Fisk, P.S.; Bromery, R.W.

    1987-07-01

    Geophysical techniques may help determine the nature and extent of faulting in the target areas, along with structural information that would be relevant to questions concerning the future integrity of a high-level-waste repository. Chapters focus on particular geophysical applications to four rock types - basalt, bedded salt, domal salt and tuff - characteristic of the sites originally proposed for site characterization. No one geophysical method can adequately characterize the geological structure beneath any site. The seismic reflection method, which is generally considered to be the most incisive of the geophysical techniques, has to date provided only marginal information on structure at the depth of the proposed repository at the Hanford, Washington, site, and no useful results at all at the Yucca Mountain, Nevada, site. This result is partially due to geological complexity beneath these sites, but may also be partially attributed to the use of inappropriate acquisition and processing parameters. To adequately characterize a site using geophysics, modifications will have to be made to standard techniques to emphasize structural details at the depths of interest. 137 refs., 43 figs., 4 tabs

  14. 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

  15. 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.

  16. History of geophysical studies at the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico

    International Nuclear Information System (INIS)

    Borns, D.J.

    1997-01-01

    A variety of geophysical methods including the spectrum of seismic, electrical, electromagnetic and potential field techniques have used support characterization, monitoring and experimental studies at the Waste Isolation Pilot Plant (WIPP). The geophysical studies have provided significant understanding of the nature of site deformation, tectonics and stability. Geophysical methods have delineated possible brine reservoirs beneath the underground facility and have defined the disturbed rock zone that forms around underground excavations. The role of geophysics in the WIPP project has evolved with the project. The early uses were for site characterization to satisfy site selection criteria or factors. As the regulatory framework for WIPP grew since 1980, the geophysics program was focused on support of experimental and field programs such as Salado hydrogeology and underground room systems and excavations. In summary, the major types of issues that geophysical studies addressed for WIPP are: Issue 1: Site Characterization; Issue 2: Castile Brine Reservoirs; Issue 3: Rustler /Dewey Lake Hydrogeology; Issue 4: Salado Hydrogeology; and Issue 5: Excavation Effects. The nature of geophysics program for WIPP has been to support investigation rather than being the principal investigation itself. The geophysics program has been used to define conceptual models (e.g., the Disturbed Rock Zone-DRZ) or to test conceptual models (e.g., high transmissivity zones in the Rustler Formation). An effect of being a support program is that as new project priorities arose the funding for the geophysics program was limited and withdrawn. An outcome is that much of the geophysics survey information resides in contractor reports since final interpretation reports were not funded

  17. Spectral analysis and filter theory in applied geophysics

    CERN Document Server

    Buttkus, Burkhard

    2000-01-01

    This book is intended to be an introduction to the fundamentals and methods of spectral analysis and filter theory and their appli­ cations in geophysics. The principles and theoretical basis of the various methods are described, their efficiency and effectiveness eval­ uated, and instructions provided for their practical application. Be­ sides the conventional methods, newer methods arediscussed, such as the spectral analysis ofrandom processes by fitting models to the ob­ served data, maximum-entropy spectral analysis and maximum-like­ lihood spectral analysis, the Wiener and Kalman filtering methods, homomorphic deconvolution, and adaptive methods for nonstation­ ary processes. Multidimensional spectral analysis and filtering, as well as multichannel filters, are given extensive treatment. The book provides a survey of the state-of-the-art of spectral analysis and fil­ ter theory. The importance and possibilities ofspectral analysis and filter theory in geophysics for data acquisition, processing an...

  18. Geophysical study of the Peinan Archaeological Site, Taiwan

    Science.gov (United States)

    Tong, Lun-Tao; Lee, Kun-Hsiu; Yeh, Chang-Keng; Hwang, Yan-Tsong; Chien, Jeng-Ming

    2013-02-01

    The Peinan archaeological site is the most intact Neolithic village with slate coffin burial complexes in Taiwan. However, the area that potentially contains significant ancient remains is covered by dense vegetation. No reliable data show the distribution of the ancient village, and no geophysical investigation has been performed at this site. To evaluate various geophysical methods under the geological setting and surface condition of the site, the physical properties of the remains were measured and four geophysical methods involving magnetic, electromagnetic (EM), electrical resistivity tomography (ERT), and ground-penetrating radar (GPR) were tested along three parallel profiles. The results imply that the EM and magnetic methods are much cost-effective and suitable for investigating the entire area. GPR and ERT methods can provide high resolution subsurface image, which are much suitable for subsequently detail investigation. The EM and magnetic surveys were thus conducted over the entire Peinan Cultural Park to understand the distribution of the ancient building remains at the Peinan site. The results of this study were verified by subsequent excavations, which indicate that the EM survey was successful in delineating the majority of the ancient village because the basements of building are highly resistive in comparison to the background sediment. The results of this investigation suggest that the ancient village was broadly distributed over the eastern part of the Peinan Culture Park and extended to the southeast.

  19. An Integral, Multidisciplinary and Global Geophysical Field Experience for Undergraduates

    Science.gov (United States)

    Vázquez, O.; Carrillo, D. J.; Pérez-Campos, X.

    2007-05-01

    The udergraduate program of Geophysical Engineering at the School of Engineering, of the Univesidad Nacional Autónoma de México (UNAM), went through an update process that concluded in 2006. As part of the program, the student takes three geophysical prospecting courses (gravity and magnetics, electric, electromagnetics, and seismic methods). The older program required a three-week field experience for each course in order to gradute. The new program considers only one extended field experience. This work stresses the importance of international academic exchange, where undergraduate students could participate, such as the Summer of Applied Geophysical Experience (SAGE), and interaction with research programs, such as the MesoAmerican Subduction Experiment (MASE). Also, we propose a scheeme for this activity based on those examples; both of them have in common real geophysical problems, from which students could benefit. Our proposal covers academic and logistic aspects to be taken into account, enhancing the relevance of interaction between other academic institutions, industry, and UNAM, in order to obtain a broader view of geophysics.

  20. The use of marine geophysical methods in Geo-Engineering investigations of Dams/ Barrages - a case study of Kosi Barrage

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Naidu, P.D.

    Geophysical Methods in Geo-Engineering Investigations of Dams/ Barrages - A Case Study of Kosi Barrage INTRODUCTION KH. Vora* P. Divakar Naidu* Dams and barrages are such civil engineering structures where foundation is submerged. The impounded water column... etc. Some other on the spot observations using pole and other elementary probing methods are in vogue. However, usually such investigations would provide only a generalised picture based on isolated data. Advent of high technology, developed over...

  1. Report of geophysical raising of the amethyst and agate in two quarries in Artigas district Uruguay

    International Nuclear Information System (INIS)

    Reitmayr, G.; Gonzalez, C.; Torterolo, M.

    1989-01-01

    In a geophysical raising of amethyst and agate was studied the possibility to apply a better suitable geophysical method. The conclusion was that the electromagnetic VLF method was suitable to identify the zones.

  2. Definition of a critical confining zone using surface geophysical methods

    International Nuclear Information System (INIS)

    Eddy-Dilek, C.A.; Looney, B.B.; Hoekstra, P.; Harthill, N.; Blohm, M.; Phillips, D.R.

    1997-01-01

    Definition of the hydrologic framework in layered sediments of fluvial and deltaic origin is a difficult challenge for environmental characterization and remediation programs due to the lithologic and stratigraphic heterogeneities inherent in these settings. The authors set out to use complementary geophysical surveys to determine the nature and extent of a deep confining unit at the Savannah River Site, South Carolina. Time Domain Electromagnetic (TDEM) soundings were used to define the electrical conductance of the clayey confining unit (aquitard), and shear-wave reflection seismic was used to define the stratigraphic framework. Based on correlations with borehole geophysical logs and sieve data, the shear-wave seismic proved capable of defining relatively fine layering in the coastal plain sediments, the upper and lower surfaces of a critical confining unit, and erosional features on the surface of the confining unit. The TDEM surveys defined the presence or absence of the clay facies of the confining unit. Moreover, by constraining the interpretation of the TDEM data with the thickness of the confining unit derived from the seismic data, the authors mapped the extent of the unit, showing where the clay is thicker, where it probably was never deposited, and where it was eroded by downcutting channels. These results have significant implications on the design and optimization of remedial systems

  3. 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. [...

  4. Proceedings of a workshop on geophysical and related geoscientific research at Chalk River, Ontario

    International Nuclear Information System (INIS)

    Thomas, M.D.; Dixon, D.F.

    1989-10-01

    A large part of the Canadian Nuclear Fuel Waste Management Program is geoscience research and development aimed at obtaining information to quantify the transport of radionuclides through the geosphere and at determining the geotechnical properties required for disposal vault design. The geosphere at potential disposal sites is characterized in part by the use of remote sensing (geophysical) methods. In 1977 public concern about the disposal of radioactive waste resulted in field work being restricted to the site of Chalk River Nuclear Laboratories, which was used to develop, evaluate and compare various techniques in order to optimize the methods for obtaining geoscience information. Methods tested at Chalk River are to be applied at other research sites. Most investigations have been carried out around Maskinonge Lake, using about thirty boreholes sink into bedrock. The boreholes provide subsurface geological information that can be used as a reference to compare the responses of various geophysical methods and equipment. Regional studies, including airborne geophysical surveys, have also been conducted. The 25 papers presented at this workshop provide comprehensive documentation of the most significant results of geophysical studies. The workshop also provided an evaluation of geophysical techniques and their utility to the Nuclear Fuel Waste Management Program

  5. Geophysical methods as a tool for improving our knowledge of ornamental rock deposits and their exploitation

    International Nuclear Information System (INIS)

    Espín de Gea, A.; Reyes Urquiza, M.; Gil Abellán, A.

    2017-01-01

    The ornamental rock sector, particularly the investigation of deposits, is not readily given to the incorporation of new technologies. The Marble Technology Center (CTM) has made advances in this sector with the implementation of geophysical techniques able to obtain subsurface information. There are still a few outcrops and active quarries where joint geophysical techniques have been applied sufficiently to obtain a three-dimensional model of the study area. The application of geophysics and more specifically, ground penetrating radar, electrical tomography and seismic refraction, when conducting research of a reservoir or outcrop, is only slightly aggressive to the environment, allowing a real knowledge of the characteristics before beginning the more aggressive work, as is the case when conducting surveys and test pits which can subsequently complement the data obtained. This makes it possible to gain a good idea of the quality of the reservoir thus allowing optimization of resources, both financial and environmental beforehand. Several studies conducted by the CTM illustrate the benefits brought by the application of these geophysical techniques as well as the weaknesses within the characteristics of the extraction sites and ornamental rock outcrops. [es

  6. Detection of concrete dam leakage using an integrated geophysical technique based on flow-field fitting method

    Science.gov (United States)

    Dai, Qianwei; Lin, Fangpeng; Wang, Xiaoping; Feng, Deshan; Bayless, Richard C.

    2017-05-01

    An integrated geophysical investigation was performed at S dam located at Dadu basin in China to assess the condition of the dam curtain. The key methodology of the integrated technique used was flow-field fitting method, which allowed identification of the hydraulic connections between the dam foundation and surface water sources (upstream and downstream), and location of the anomalous leakage outlets in the dam foundation. Limitations of the flow-field fitting method were complemented with resistivity logging to identify the internal erosion which had not yet developed into seepage pathways. The results of the flow-field fitting method and resistivity logging were consistent when compared with data provided by seismic tomography, borehole television, water injection test, and rock quality designation.

  7. Geophysical study in waste landfill localized above fractured rocks

    Directory of Open Access Journals (Sweden)

    Ariveltom Cosme da Silva

    2011-08-01

    Full Text Available Geophysical survey is an important method for investigation of contaminated areas used in the characterization of contrasting physical properties in the presence of pollutants. This work applied the geophysical methods of Electrical Resistivity and Self Potential in waste landfill, located in Caçapava do Sul city, RS. The landfill is located over fractured metamorphic rocks. Eight lines of electrical profiling with 288 measures of self potential were done. In addition, 83 measurements of direction and dip of fractures were taken. The application of spontaneous potential method permitted to detect the direction of groundwater flow. The electrical resistivity measurements allowed the identification of low-intensity anomalies associated with the presence of leachate. There is a relationship between anomalous zones and the directions of fractures.

  8. 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

  9. Geophysical and solar activity indices

    Science.gov (United States)

    Bossy, L.; Lemaire, J.

    1984-04-01

    A large number of geophysicists try to correlate their observations with one or even a series of different geophysical or solar activity indices. Yet the right choice of the most appropriate index with which to correlate depends mainly on our understanding of the physical cause-effect relationship between the new set of observations and the index chosen. This best choice will therefore depend on our good understanding of the methods of measurement and derivation of the adopted index in such correlative studies. It relies also on our awareness of the range of applicability of the indices presently available as well as on our understanding of their limitations. It was to achieve these goals that a series of general lectures on geophysical and solar activity indices was organized by L. Bossy and J. Lemaire (Institut d'Aeronomie Spatiale de Belgique (IASB), Brussels), March 26-29, 1984 at Han-sur-Lesse, Belgium.

  10. Engineering-geophysical criteria for evaluating the development stages of landslides in loess rocks

    Energy Technology Data Exchange (ETDEWEB)

    Abdullayev, S K

    1981-01-01

    As a result of conducting geophysical observations on landslide slopes formed by loess rocks, with their artifical moistening, quantitiative engineering-geophysical criteria were obtained which characterize the basic stages of landslide development. The studies were conducted by surface methods of electrical resistance and seismometry conducted directly in the massif. According to the indicators of moisture content, state of comminution, compactness calculated with the help of geophysical parameters, the stage of preparation and movement of landslides are characterized.

  11. geophysical and geochemical characterization of zango abattoir

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    disposal of hazardous materials, fresh groundwater supplies ... in the groundwater flow system may change considerably the conductivity of the polluted zone; hence the Geo-electric and. Electromagnetic (EM) geophysical methods could effectively be ... this field strength and phase displacement around a fracture zone.

  12. 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

  13. Proceedings of the 94th SEGJ (The Society of Exploration Geophysicists of Japan) Conference; Butsuri tansa gakkai dai 94 kai (1996 nendo shunki) gakujutsu koenkai koen ronbunshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The fiscal 1996 SEGJ Conference was held in Tokyo during May 15-17, and 101 papers were reported. As for disaster prevention, the following were reported: Questionnaire investigation for the earthquake, Localization of b-values and maximum earthquakes, Cooperative measurements of microtremors in the north-eastern region of Nishinomiya City, Hyogo Pref., etc. As to elastic wave data recording and modeling data processing, Optimization of dynamite source depth for seismic surveys, Simulation of breakage of heterogeneous materials caused by detonative loading, etc. With relation to archeology, radar, and refraction method, Reexamining results of Iwatoyama tumulus by means of directive antenna, Application of geophysical method to investigation of old castle, etc. Concerning microtremors and surface waves, Estimation of shallow ground structure using short-period microtremors array observation, etc. Besides, papers were reported on electromagnetism, tomography, gravity/magnetism/numerical calculation, measurement while drilling, etc. Moreover, a symposium on underground structures in the Hanshin/Awaji area as viewed from geophysical exploration was held presenting nine papers.

  14. Application of Geophysical Method for Determining Seawater Intrusion in Coastal Aquifer

    International Nuclear Information System (INIS)

    Mohd Muzamil Mohd Hashim; Kamarudin Samuding; Mohd Hafiz Zawawi; Daung, J.A.D.; Mohd Hafiz Zulkurnain; Kamaruzaman Mohamad

    2016-01-01

    A study of seawater intrusion has been proposed in the coastal area of Pahang. Electrical resistivity tomography (ERT) is a geophysical technique that used in this study. The survey was conducted at UMP, Tanjung Batu and Nenasi using Wenner-Schlumberger protocol. Electrical resistivity profile obtained from the survey indicates an area with low resistivity value (<5Ωm) associated with the resistivity value of seawater. (author)

  15. 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.)

  16. An application of the geophysical methods and ALS DTM for the identification of the geological structure in the Kraśnik region - Lublin Upland, Poland

    Science.gov (United States)

    Kamiński, Mirosław

    2017-11-01

    The purpose of the study was the assessment of the viability of selected geophysical methods and the Airborne Laser Scanning (ALS) for the identification and interpretation of the geological structure. The studied area is covered with a dense forest. For this reason, the ALS numerical terrain model was applied for the analysis of the topography. Three geophysical methods were used: gravimetric, in the form of a semi-detailed gravimetric photograph, Vertical Electrical Sounding (VES), and Electrical Resistivity Tomography (ERT). The numerical terrain model enabled the identification of Jurassic limestone outcrops and interpretation of the directions of the faults network. The geological interpretation of the digitally processed gravimetric data enabled the determination of the spatial orientation of the synclines and anticlines axes and of the course directions of main faults. Vertical Electrical Sounding carried along the section line perpendicular to the Gościeradów anticline axis enabled the interpretation of the lithology of this structure and identification of its complex tectonic structure. The shallow geophysical surveys using the ERT method enabled the estimation of the thickness of Quaternary formations deposited unconformably on the highly eroded Jurassic limestone outcrop. The lithology of Quaternary, Cretaceous and Jurassic rocks was also interpreted.

  17. Use of improved hydrologic testing and borehole geophysical logging methods for aquifer characterization

    International Nuclear Information System (INIS)

    Newcomer, D.R.; Hall, S.H.; Vermeul, V.R.

    1996-01-01

    Depth-discrete aquifer information was obtained using recently developed adaptations and improvements to conventional characterization techniques. These improvements included running neutron porosity and bulk density geophysical logging tools through a cased hole, performing an enhanced point-dilution tracer test for monitoring tracer concentration as a function of time and depth, and using pressure derivatives for diagnostic and quantitative analysis of constant rate discharge test data. Data results from the use of these techniques were used to develop a conceptual model of a heterogeneous aquifer. Depth-discrete aquifer information was required to effectively design field-scale deployment and monitoring of an in situ bioremediation technology. The bioremediation study site is located on the US Department of Energy's Hanford site. The study is being conducted by the Pacific Northwest National Laboratory to demonstrate in situ bioremediation of carbon tetrachloride (CCl 4 ). Geophysical logging and point-dilution tracer test results provided the relative distribution of porosity and horizontal hydraulic conductivity, respectively, with depth and correlated well. Hydraulic pumping tests were conducted to estimate mean values for transmissivity and effective hydraulic conductivity. Tracer test and geophysical logging results indicated that ground water flow was predominant in the upper approximate 10 feet of the aquifer investigated. These results were used to delineate a more representative interval thickness for estimating effective hydraulic conductivity. Hydraulic conductivity, calculated using this representative interval, was estimated to be 73 ft/d, approximately three times higher than that calculated using the full length of the screened test interval

  18. 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.

  19. 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...

  20. Cyclic Investigation of Geophysical Studies in the Exploration and Discovery of Natural Resources in Our Country

    International Nuclear Information System (INIS)

    Gonulalan, A. U.

    2007-01-01

    Although the methods of exploration geophysics were first utilized after the discovery of an oil field in 1921, they have also applied in the old centuries. Likewise, the half of the total production in the United States of America is covered by new oil fields discovered by utilizing geophysical methods. The industry's energy necessity increases the interest to oil. The investments in the field of geophysics by the companies which makes large amount of money in order to discover new oil fields, widespread use of computers, the developments of space technology and world-wide nuclear competition even though its great danger for human beings have great share in the development of geophysics. Our country has 18 different types mines which has more than 10 billion $ potential. Geophysical engineers have great Kowledge and labor in the discovery of 1,795 trillion wealth from borax to building stone, and 60 billion $ oil and gas. On the other hand, as 1,5 billion investment in the field of geophysics is only 0.08 % of total investments, the increase of investments will add more contribution

  1. PREFACE: Padjadjaran Earth Dialogues: International Symposium on Geophysical Issues, PEDISGI

    Science.gov (United States)

    Rosandi, Y.; Urbassek, H. M.; Yamanaka, H.

    2016-01-01

    This issue of IOP Conference Series: Earth and Environmental Science contains selected papers presented at the Padjadjaran Earth Dialogues: International Symposium on Geophysical Issues, PEDISGI. The meeting was held from June 8 to 10, 2015, at the Bale-Sawala of Universitas Padjadjaran in Jatinangor, Indonesia. The PEDISGI is a symposium to accommodate communication between researchers, in particular geophysicists and related scientists, and to enable sharing of knowledge and research findings concerning local and global geophysical issues. The symposium was attended by 126 participants and 64 contributors from Indonesian universities and the neighbouring countries in four categories, viz. Theoretical and Computational Geophysics, Environmental Geophysics, Geophysical Explorations, and Geophysical Instrumentations and Methods. The symposium was accompanied by a dialog, discussing a chosen topic regarding environmental and geological problems of relevance for the Indonesian archipelago and the surrounding regions. For this first event the topic was ''The formation of Bandung-Basin between myths and facts: Exemplary cultural, geological and geophysical study on the evolution of the earth surface'', presented by invited speakers and local experts. This activity was aimed at extending our knowledge on this particular subject, which may have global impact. This topic was augmented by theoretical background lectures on the earth's surface formation, presented by the invited speakers of the symposium. The meeting would not have been successful without the assistance of the local organizing committee. We want to specially thank Irwan A. Dharmawan for managing the programme, Anggie Susilawati and Mia U. Hasanah for the conference administration, and Dini Fitriani for financial management. We also thank the National Geographic Indonesia for its support via the Business to Business Collaboration Program. The conference photograph can be viewed in the PDF.

  2. AfricaArray International Geophysics Field School: Applications of Near Surface Geophysics to challenges encountered in mine planning

    Science.gov (United States)

    Webb, S. J.; Jones, M. Q.; Durrheim, R. J.; Nyblade, A.; Snyman, Q.

    2012-12-01

    students are the geophysics Honours students (~4th year undergraduates). In addition, up to 8 students from all over Africa are included in the program to help address practical training in Africa. The final cohort are minority students from the USA. Participants spend a week planning and costing out surveys, a week in the field collecting data using different methods including: gravity, DGPS, magnetics, resistivity, refraction seismic, EM methods, core logging and physical property measurements. The final week is spent interpreting and integrating their results. Graduate students are given the opportunity to instruct on the field school and manage the logistics for a particular method. The field school is unique in Africa and satisfies a need for practical training with limited resources, with a rare blend of cultural interactions!

  3. Preclosure monitoring and performance confirmation at Yucca Mountain: Applicability of geophysical, geohydrological, and geochemical methods

    International Nuclear Information System (INIS)

    Tsang, C.F.

    1989-06-01

    The present paper presents considerations on studies that would be required for preclosure monitoring and performance confirmation of a nuclear waste geologic repository in an unsaturated zone. The critical parameters that should be monitored are reviewed and two scales of measurement relevant to monitoring activities, room scale and repository scale, are taken as a framework for investigation. A number of monitoring methods based on geophysics, geohydrology, and geochemistry are briefly summarized for their potential usefulness for preclosure monitoring and performance confirmation of the geologic repository. Particular emphasis is given to measurement of the spatial distribution of parameters in contrast to single-point measurements of quantities. 12 refs., 1 fig., 1 tab

  4. 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

  5. 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

  6. Geophysical contribution for Folha Patos (PI, Brazil)

    International Nuclear Information System (INIS)

    Rodrigues, J.C.; Mota, A.C.; Metelo, M.J.; Vasconcelos, R.M. de

    1990-01-01

    As a part of PLGB (Brazilian Geologic reconnaissance program), executed in 1986-1989 period by Companhia de Pesquisa de Recursos Minerais - CPRM to the Departamento Nacional da Producao Mineral - DNPM, geophysical studies were carried out in the Patos Quadrangle (SB. 24-Y-C-V). Gravimetric, magnetometric and scintillometric methods were performed over selected profiles, and the interpretation of aerial gamma-spectrometric maps (total, potassium, uranium and thorium channels) were integrated with geologic data. Computer programs Magpoly and Gravpoly were utilized in modelling geophysical surface data. Results of theses studies were auxiliary to the geological mapping of that area, specially in localizing lithological contacts and differentiations, tectonic structures, and revealed the structural compartimentation among crustal segments with distinct metamorphic grades. (author)

  7. 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)

  8. A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone

    Energy Technology Data Exchange (ETDEWEB)

    David Alumbaugh; Douglas LaBrecque; James Brainard; T.C. (Jim) Yeh

    2004-01-22

    The primary purpose of this project was to employ two geophysical imaging techniques, electrical resistivity tomography and cross-borehole ground penetrating radar, to image a controlled infiltration of a saline tracer under unsaturated flow conditions. The geophysical techniques have been correlated to other more traditional hydrologic measurements including neutron moisture measurements and induction conductivity logs. Images that resulted during two successive infiltrations indicate the development of what appear to be preferential pathways through the finer grained materials, although the results could also be produced by cationic capture of free ions in clays. In addition the site as well as the developing solute plume exhibits electrical anisotropy which is likely related to flow properties. However the geologic significance of this phenomenon is still under investigation.

  9. A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone

    International Nuclear Information System (INIS)

    Alumbaugh, David; LaBrecque, Douglas; Brainard, James; Yeh, T.C.-Jim

    2004-01-01

    The primary purpose of this project was to employ two geophysical imaging techniques, electrical resistivity tomography and cross-borehole ground penetrating radar, to image a controlled infiltration of a saline tracer under unsaturated flow conditions. The geophysical techniques have been correlated to other more traditional hydrologic measurements including neutron moisture measurements and induction conductivity logs. Images that resulted during two successive infiltrations indicate the development of what appear to be preferential pathways through the finer grained materials, although the results could also be produced by cationic capture of free ions in clays. In addition the site as well as the developing solute plume exhibits electrical anisotropy which is likely related to flow properties. However the geologic significance of this phenomenon is still under investigation

  10. Reservoir and civil engineering geophysics (CD-Rom); Geophysique de gisement et de genie civil (CD-Rom)

    Energy Technology Data Exchange (ETDEWEB)

    Mari, J.L.; Chapellier, D.

    1999-07-01

    This CD-Rom is a pedagogical tool developed from the book 'field and civil engineering geophysics' (Technip ed., 1998). It presents the geophysical methods (surface and well geophysical surveys, radar surveys and well logging) and their application in the study of oil fields and also in civil engineering. Several cartoons illustrate the principle of methods, their domain of use and their limitations. It covers the following topics: surface seismic surveys (waves propagation, equipments, reflexion and refraction seismic surveys, surface waves); well seismic surveys (operation, data processing, imaging); well logging (acoustic, nuclear,electrical and others, methods of interpretation); radar surveys (principle, surface, wells, possibilities and limitations). (J.S.)

  11. 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)

  12. Summary of coal problems and possible geophysics solutions

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2015-01-01

    Full Text Available problem description concludes with a list of geophysical methods that may be applicable. The application summary table at the end of the chapter aims to integrate all of this information into a single, one-page reference guide....

  13. Integrated application of the database for airborne geophysical survey achievement information

    International Nuclear Information System (INIS)

    Ji Zengxian; Zhang Junwei

    2006-01-01

    The paper briefly introduces the database of information for airborne geophysical survey achievements. This database was developed on the platform of Microsoft Windows System with the technical methods of Visual C++ 6.0 and MapGIS. It is an information management system concerning airborne geophysical surveying achievements with perfect functions in graphic display, graphic cutting and output, query of data, printing of documents and reports, maintenance of database, etc. All information of airborne geophysical survey achievements in nuclear industry from 1972 to 2003 was embedded in. Based on regional geological map and Meso-Cenozoic basin map, the detailed statistical information of each airborne survey area, each airborne radioactive anomalous point and high field point can be presented visually by combining geological or basin research result. The successful development of this system will provide a fairly good base and platform for management of archives and data of airborne geophysical survey achievements in nuclear industry. (authors)

  14. Geophysical survey aimed at selecting the radioactive waste repository site (Czech republic

    Directory of Open Access Journals (Sweden)

    Dušan Dostál

    2007-01-01

    Full Text Available G IMPULS Praha has been executing a set of geophysical measurements for the Radioactive Waste Repository Authority of the Czech Republic from 2001 (the work continues to be carried out. The measurements are aimed at studying the behaviour of the rock massif, focusing on the Excavation Damaged or Disturbed Zone (EDZ and on selecting an appropriate area for the radioactive material repository site. The geophysical studies use a complex of methods as follows: Airborne geophysical measurement (regional studies, Seismic measurement (detailed studies, G.P.R. (detailed studies, Resistivity tomography (detailed studies, Geoelectric measurement and magnetic survey (stray earth currents. The paper informs about first results and conclusions. The airborne work was executed as a part of the complex study of „GEOBARIERA“ the group and the geophysical measurements of EDZ were executed in co-operation with the Czech Geological Survey.

  15. Status of data, major results, and plans for geophysical activities, Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, H.W. [Geological Survey, Menlo Park, CA (USA); Hardin, E.L. [Science Applications International Corp., Las Vegas, NV (USA); Nelson, P.H. [Geological Survey, Denver, CO (USA)] [eds.

    1990-07-01

    This report describes past and planned geophysical activities associated with the Yucca Mountain Project and is intended to serve as a starting point for integration of geophysical activities. This report relates past results to site characterization plans, as presented in the Yucca Mountain Site Characterization Plan (SCP). This report discusses seismic exploration, potential field methods, geoelectrical methods, teleseismic data collection and velocity structural modeling, and remote sensing. This report discusses surface-based, airborne, borehole, surface-to-borehole, crosshole, and Exploratory Shaft Facility-related activities. The data described in this paper, and the publications discussed, have been selected based on several considerations; location with respect to Yucca Mountain, whether the success or failure of geophysical data is important to future activities, elucidation of features of interest, and judgment as to the likelihood that the method will produce information that is important for site characterization. 65 refs., 19 figs., 12 tabs.

  16. Status of data, major results, and plans for geophysical activities, Yucca Mountain Project

    International Nuclear Information System (INIS)

    Oliver, H.W.; Hardin, E.L.; Nelson, P.H.

    1990-07-01

    This report describes past and planned geophysical activities associated with the Yucca Mountain Project and is intended to serve as a starting point for integration of geophysical activities. This report relates past results to site characterization plans, as presented in the Yucca Mountain Site Characterization Plan (SCP). This report discusses seismic exploration, potential field methods, geoelectrical methods, teleseismic data collection and velocity structural modeling, and remote sensing. This report discusses surface-based, airborne, borehole, surface-to-borehole, crosshole, and Exploratory Shaft Facility-related activities. The data described in this paper, and the publications discussed, have been selected based on several considerations; location with respect to Yucca Mountain, whether the success or failure of geophysical data is important to future activities, elucidation of features of interest, and judgment as to the likelihood that the method will produce information that is important for site characterization. 65 refs., 19 figs., 12 tabs

  17. An application of the geophysical methods and ALS DTM for the identification of the geological structure in the Kraśnik region – Lublin Upland, Poland

    Directory of Open Access Journals (Sweden)

    Kamiński Mirosław

    2017-01-01

    Full Text Available The purpose of the study was the assessment of the viability of selected geophysical methods and the Airborne Laser Scanning (ALS for the identification and interpretation of the geological structure. The studied area is covered with a dense forest. For this reason, the ALS numerical terrain model was applied for the analysis of the topography. Three geophysical methods were used: gravimetric, in the form of a semi-detailed gravimetric photograph, Vertical Electrical Sounding (VES, and Electrical Resistivity Tomography (ERT. The numerical terrain model enabled the identification of Jurassic limestone outcrops and interpretation of the directions of the faults network. The geological interpretation of the digitally processed gravimetric data enabled the determination of the spatial orientation of the synclines and anticlines axes and of the course directions of main faults. Vertical Electrical Sounding carried along the section line perpendicular to the Gościeradów anticline axis enabled the interpretation of the lithology of this structure and identification of its complex tectonic structure. The shallow geophysical surveys using the ERT method enabled the estimation of the thickness of Quaternary formations deposited unconformably on the highly eroded Jurassic limestone outcrop. The lithology of Quaternary, Cretaceous and Jurassic rocks was also interpreted.

  18. The University of Texas Institute for Geophysics' Marine Geology and Geophysics Field Course: A Hand-On Education Approach to Applied Geophysics

    Science.gov (United States)

    Davis, M. B.; Goff, J.; Gulick, S. P. S.; Fernandez, R.; Duncan, D.; Saustrup, S.

    2016-12-01

    The University of Texas Institute for Geophysics, Jackson School of Geosciences, offers a 3-week marine geology and geophysics field course. 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, and sediment sampling and analysis. Students first participate in 3 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 at locations that provide an opportunity to investigate coastal and continental shelf processes. Teams of students rotate between UTIG's 26' R/V Scott Petty and NOAA's 82' R/V Manta. They assist with survey design, instrumentation set up, and learn about acquisition, quality control, and safe instrument deployment. Teams also process data and analyze samples in onshore field labs. During the final week teams integrate, interpret, and visualize data in a final project using industry-standard software. The course concludes with team presentations on their interpretations 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 high instructor/student ratio (sixteen students, three faculty, and three teaching assistants). Post-class, students may incorporate course data in senior honors or graduate thesis and are encouraged to publish and present results at national meetings. This course (to our knowledge) remains the only one of its kind, satisfies field experience requirements for some degree programs, and provides an alternative to land-based field courses. Alumni note the course's applicability to energy, environmental, and geotechnical industries as well as coastal restoration/management fields.

  19. Connections between borehole geophysical parameters of the quality of cement raw materials

    International Nuclear Information System (INIS)

    Szabo, L.; Illes, A.

    1978-01-01

    The raw materials for the cement industry are prospected - according to the recommendations of national authorities - by geophysical methods, too. These include not the determination of the deposit boundary, but also an estimation of the quality of limestone and clay from the point of cement manufacture. No forerunners of such tests exist, so new methods were elaborated. After 12 years of site tests it was found that the correlation between laboratory quality tests and certain geophysical parameters of clay deposits is fair but less close in case of limestone deposits. (author)

  20. 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)

  1. The Expanding Marketplace for Applied Geophysics

    Science.gov (United States)

    Carlson, N.; Sirles, P.

    2012-12-01

    While the image of geophysics for the proverbial "layman" often seems limited to volcanoes and earthquakes, and to the geoscientist this image enlarges to include oil or minerals exploration and whole earth studies, there has been a steady increase in the application of geophysics into the realm of "daily life", such as real estate deals, highway infrastructure, and flood protection. This expansion of applications can be attributed to the improved economics from advances in equipment and interpretation. Traditional geophysical methods that at one time often only fit within the budgets of oil, gas, and minerals exploration programs can now be economically applied to much smaller scale needs like contaminant mapping, landfill delineation, and levee investigations. A real-world, economic example of this expanding marketplace is our company, which began very small and was aimed almost exclusively at the minerals exploration market. Most of our growth has been in the last 10 years, when we have expanded to five offices and a staff with almost 40 geoscientist degrees (21 in geophysics); much of this growth has been in the non-oil, non-minerals arenas. While much of our work still includes minerals exploration, other projects this year include wind-farm foundation studies, cavity detection above underground nuclear tests, landfill studies, acid mine drainage problems, and leaks in evaporation ponds. A methodology example of this expanding market is the induced polarization (IP) survey, once primarily used for minerals exploration, particularly large porphyry copper deposits, but now efficient enough to also use in environmental studies. The IP method has been particularly useful in delineating and characterizing old, poorly documented landfills, and recent research suggests it may also be useful in monitoring the accelerated biodegradation processes used in some cases to rehabilitate the sites. Compared to temperature monitoring systems, IP may be more useful in providing

  2. Geophysical considerations of geothermics

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, M

    1967-01-01

    The development and utilization of geothermal energy is described from the standpoint of geophysics. The internal temperature of the Earth and the history and composition of magmas are described. Methods of exploration such as gravity, magnetic, thermal and electrical surveys are discussed, as are geochemical and infrared photogrammetric techniques. Examples are provided of how these techniques have been used in Italy and at the Matsukawa geothermal field in Japan. Drilling considerations such as muds, casings and cementing materials are discussed. Solutions are proposed for problems of environmental pollution and plant expansion.

  3. Analysis and interpretation of geophysical surveys in archaeological sites employing different integrated approach.

    Science.gov (United States)

    Piro, Salvatore; Papale, Enrico; Kucukdemirci, Melda; Zamuner, Daniela

    2017-04-01

    Non-destructive ground surface geophysical prospecting methods are frequently used for the investigation of archaeological sites, where a detailed physical and geometrical reconstructions of hidden volumes is required prior to any excavation work. All methods measure the variations of single physical parameters, therefore if these are used singularly, they could not permit a complete location and characterization of anomalous bodies. The probability of a successful result rapidly increases if a multhimethodological approach is adopted, according to the logic of objective complementarity of information and of global convergence toward a high quality multiparametric imaging of the buried structures. The representation of the static configuration of the bodies in the subsoil and of the space-time evolution of the interaction processes between targets and hosting materials have to be actually considered fundamental elements of primary knowledge in archaeological prospecting. The main effort in geophysical prospecting for archaeology is therefore the integration of different, absolutely non-invasive techniques, especially if managed in view of a ultra-high resolution three-dimensional (3D) tomographic representation mode. Following the above outlined approach, we have integrated geophysical methods which measure the variations of potential field (gradiometric methods) with active methods which measure the variations of physical properties due to the body's geometry and volume (GPR and ERT). In this work, the results obtained during the surveys of three archaeological sites, employing Ground Penetrating Radar (GPR), Electrical Resistivity Tomography (ERT) and Fluxgate Differential Magnetic (FDM) to obtain precise and detailed maps of subsurface bodies, are presented and discussed. The first site, situated in a suburban area between Itri and Fondi, in the Aurunci Natural Regional Park (Central Italy), is characterized by the presence of remains of past human activity

  4. INEL cold test pit demonstration of improvements in information derived from non-intrusive geophysical methods over buried waste sites

    International Nuclear Information System (INIS)

    1994-01-01

    Under Contract between US DOE Idaho National Engineering Laboratory (INEL) and the Blackhawk Geosciences Division of Coleman Research Corporation (BGD-CRC), geophysical investigations were conducted to improve the detection of buried wastes. Site characterization is a costly and time consuming process with the most costly components being drilling, sampling, and chemical analysis of samples. There is a focused effort at US DOE and other agencies to investigate methodologies that reduce costs and shorten the time between characterization and clean-up. These methodologies take the form of employing non-invasive (geophysical) and minimal invasive (e.g., cone penetrometer driving) techniques of characterization, and implementing a near real-time, rational decision-making process (Expedited Site Characterization). Over the Cold Test Pit (CTP) at INEL, data were acquired with multiple sensors on a dense grid. Over the CTP the interpretations inferred from geophysical data are compared with the known placement of various waste forms in the pit. The geophysical sensors employed were magnetics, frequency and time domain electromagnetics, and ground penetrating radar. Also, because of the high data density acquired, filtering and other data processing and imaging techniques were tested. The conclusions derived from the geophysical surveys were that pit boundaries, berms between cells within the pit, and individual objects placed in the pit were best mapped by the new Geonics EM61 time domain EM metal detector. Part of the reason for the effectiveness of the time domain metal detector is that objects buried in the pit are dominantly metallic. Also, the utility of geophysical data is significantly enhanced by dimensional and 3-dimensional imaging formats. These images will particularly assist remediation engineers in visualizing buried wastes

  5. Correlation of Geophysical and Geotechnical Methods for Sediment Mapping in Sungai Batu, Kedah

    Science.gov (United States)

    Zakaria, M. T.; Taib, A.; Saidin, M. M.; Saad, R.; Muztaza, N. M.; Masnan, S. S. K.

    2018-04-01

    Exploration geophysics is widely used to map the subsurface characteristics of a region, to understand the underlying rock structures and spatial distribution of rock units. 2-D resistivity and seismic refraction methods were conducted in Sungai Batu locality with objective to identify and map the sediment deposit with correlation of borehole record. 2-D resistivity data was acquire using ABEM SAS4000 system with Pole-dipole array and 2.5 m minimum electrode spacing while for seismic refraction ABEM MK8 seismograph was used to record the seismic data and 5 kg sledgehammer used as a seismic source with geophones interval of 5 m spacing. The inversion model of 2-D resistivity result shows that, the resistivity values 500 Ωm as the hard layer for this study area. The seismic result indicates that the velocity values 3600 m/s interpreted as the hard layer in this locality.

  6. Analysis of Complex Marine Hazards on the Romanian Black Sea Shelf Using Combined Geophysical Methods

    Science.gov (United States)

    Samoila, I. V.; Radulescu, V.; Moise, G.; Diaconu, A.; Radulescu, R.

    2017-12-01

    Combined geophysical acquisition technologies including High Resolution 2D Seismic (HR2D), Multi-Beam Echo-Sounding (MBES), Sub-Bottom Profiling (SBP) and Magnetometry were used in the Western Black Sea (offshore Romania) to identify possible geohazards, such as gas escaping surface sediments and tectonic hazard areas up to 1 km below the seafloor. The National Project was funded by the Research and Innovation Ministry of Romania, and has taken place over 1.5 years with the purpose of creating risk maps for the surveyed pilot area. Using an array of geophysical methods and creating a workflow to identify geohazard susceptible areas on the Romanian Black Sea continental shelf is important and beneficial for future research projects. The SBP and MBES data show disturbed areas that can be interpreted as gas escapes on the surface of the seafloor, and some escapes were confirmed on the HR2D profiles. Shallow gas indicators like gas chimneys and acoustic blanking are usually delimited by vertical, sub-vertical and/or quasi-horizontal faults that mark possible hazard areas on shallow sedimentary sections. Interpreted seismic profiles show three main markers: one delimiting the Pliocene-Quaternary boundary and two for the Miocene (Upper and Lower). Vertical and quasi-horizontal faults are characteristic for the Upper Miocene, while the Lower Miocene has NW-SE horizontal faults. Faults and possible hazard areas were marked on seismic sections and were further correlated with the MBES, SBP, Magnetometry and previously recorded data, such as earthquake epicenters scattered offshore in the Western Black Sea. The main fault systems likely to cause those earthquakes also aid the migration of gas if the faults are not sealed. We observed that the gas escapes were correlated with faults described on the recent seismic profiles. Mapping hazard areas will have an important contribution to better understand the recent evolution of the Western Black Sea basin but also for projecting

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

    African Journals Online (AJOL)

    ADOWIE PERE

    Environ. Manage. May. 2017. Vol. 21 (3) 527-535. Full-text Available Online at ... is of equal importance with the air we breathe in ... numerical modeling solutions. The electrical geophysical survey method is the .... VES data at twelve (12) sounding points as shown in figure 2; five along traverse one; two along traverse two,.

  8. The value of DCIP geophysical surveys for contaminated site investigations

    DEFF Research Database (Denmark)

    Balbarini, Nicola; Rønde, Vinni Kampman; Maurya, Pradip Kumar

    an old factory site by combining traditional geological, hydrological, and contaminant concentration data with DCIP surveys. The plume consisted of xenobiotic organic compounds and inorganics. The study assesses benefits and limitations of DCIP geophysics for contaminated site investigations. A 3D......Geophysical methods are increasingly being used in contaminant hydrogeology to map lithology, hydraulic properties, and contaminant plumes with a high ionic strength. Advances in the Direct Current resistivity and Induced Polarization (DCIP) method allow the collection of high resolution three...... water and below the streambed. Surface DCIP surveys supported the characterization of the spatial variability in geology, hydraulic conductivity and contaminant concentration. Though DCIP data interpretation required additional borehole data, the DCIP survey reduced the number of boreholes required...

  9. Addressing the difficulty of changing fields in geophysics

    Science.gov (United States)

    Civilini, F.; Savage, M. K.

    2014-12-01

    Geophysics is a wonderfully diverse field of study, encompassing a variety of disciplines greatly different from one other. Even within the same discipline, various branches of study can have drastically different vocabulary and methodologies. The difficulty of breaking this "jargon" barrier is also an important reminder for scientists of how critical it is to clearly and concisely convey information. This presentation will focus on strategies that students can focus on to ease a transition between fields in geophysics. I believe that a student changing disciplines should proceed in the following steps: [1] Do a cursory literature review to find a review paper of the desired topic and work backwards through the details until a level of understanding or recognition is reached, [2] Obtain a clear physical understanding of the data and methods of the proposed study, and [3] Establish a support network through the research group or elsewhere which will recognize the areas in which the student is behind and offer remedies in a supportive and productive manner. These strategies are based on my own personal experience changing from music to geophysics in my undergrad and working on projects spanning various subdisciplines of geophysics during my Masters and PhD. It is worthwhile for research groups to spend the time to mentor students switching from other disciplines because those students will in time be able to observe the research in a different way than their peers, and easily adapt to changes of direction within the research.

  10. INEL cold test pit demonstration of improvements in information derived from non-intrusive geophysical methods over buried waste sites

    International Nuclear Information System (INIS)

    1993-01-01

    The objectives of this research project were to lay the foundation for further improvement in the use of geophysical methods for detection of buried wastes, and to increase the information content derived from surveys. Also, an important goal was to move from mere detection to characterization of buried wastes. The technical approach to achieve these objectives consisted of: (1) Collect a data set of high spatial density; (2) Acquire data with multiple sensors and integrate the interpretations inferred from the various sensors; (3) Test a simplified time domain electromagnetic system; and (4) Develop imaging and display formats of geophysical data readily understood by environmental scientists and engineers. The breadth of application of this work is far reaching. Not only are uncontrolled waste pits and trenches, abandoned underground storage tanks, and pipelines found throughout most US DOE facilities, but also at military installations and industrial facilities. Moreover, controlled land disposal sites may contain ''hot spots'' where drums and hazardous material may have been buried. The technologies addressed by the R ampersand D will benefit all of these activities

  11. Methodological Developments in Geophysical Assimilation Modeling

    Science.gov (United States)

    Christakos, George

    2005-06-01

    This work presents recent methodological developments in geophysical assimilation research. We revisit the meaning of the term "solution" of a mathematical model representing a geophysical system, and we examine its operational formulations. We argue that an assimilation solution based on epistemic cognition (which assumes that the model describes incomplete knowledge about nature and focuses on conceptual mechanisms of scientific thinking) could lead to more realistic representations of the geophysical situation than a conventional ontologic assimilation solution (which assumes that the model describes nature as is and focuses on form manipulations). Conceptually, the two approaches are fundamentally different. Unlike the reasoning structure of conventional assimilation modeling that is based mainly on ad hoc technical schemes, the epistemic cognition approach is based on teleologic criteria and stochastic adaptation principles. In this way some key ideas are introduced that could open new areas of geophysical assimilation to detailed understanding in an integrated manner. A knowledge synthesis framework can provide the rational means for assimilating a variety of knowledge bases (general and site specific) that are relevant to the geophysical system of interest. Epistemic cognition-based assimilation techniques can produce a realistic representation of the geophysical system, provide a rigorous assessment of the uncertainty sources, and generate informative predictions across space-time. The mathematics of epistemic assimilation involves a powerful and versatile spatiotemporal random field theory that imposes no restriction on the shape of the probability distributions or the form of the predictors (non-Gaussian distributions, multiple-point statistics, and nonlinear models are automatically incorporated) and accounts rigorously for the uncertainty features of the geophysical system. In the epistemic cognition context the assimilation concept may be used to

  12. 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

  13. 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

  14. Comparison of 3-D geological and geophysical investigation methods in boreholes KI-KR1 at Aeaenekoski Kivetty site and RO-KR3 at Kuhmo Romuvaara site

    International Nuclear Information System (INIS)

    Labbas, K.

    1997-01-01

    The study is a part of the radioactive waste disposal investigations in Finland with the aim to compare three-dimensional geological and geophysical methods providing information on geologic fractures. Compared and described are the methods: core analysis, borehole television, dipmeter, borehole televiewer and differential flow measurements. (35 refs.)

  15. 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...

  16. Evaluation of geophysical borehole studies

    International Nuclear Information System (INIS)

    Brotzen, O.; Duran, O.; Magnusson, K.Aa.

    Four studies concerning geophysical investigations and TV inspection in boreholes in connection with KBS studies at Finnsjoe, Karlshamn, Kraakemaala and Stripa and PRAV's studies at Studsvik have been evaluated. This has led to proposals concerning the choice of instruments and methods for future studies and a review of future work required. The evaluation has shown that the following borehole measurements are of primary interest in the continued work: Determinations of temperature and resistivity of the borehole liquid, resistance and resistivity measurements, SP, Sonic, Caliper and VLF. TV inspection, IP and gamma-gamma should also be included in the arsenal of available test methods.(author)

  17. 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

  18. Integrated use of surface geophysical methods for site characterization — A case study in North Kingstown, Rhode Island

    Science.gov (United States)

    Johnson, Carole D.; Lane, John W.; Brandon, William C.; Williams, Christine A.P.; White, Eric A.

    2010-01-01

    A suite of complementary, non‐invasive surface geophysical methods was used to assess their utility for site characterization in a pilot investigation at a former defense site in North Kingstown, Rhode Island. The methods included frequency‐domain electromagnetics (FDEM), ground‐penetrating radar (GPR), electrical resistivity tomography (ERT), and multi‐channel analysis of surface‐wave (MASW) seismic. The results of each method were compared to each other and to drive‐point data from the site. FDEM was used as a reconnaissance method to assess buried utilities and anthropogenic structures; to identify near‐surface changes in water chemistry related to conductive leachate from road‐salt storage; and to investigate a resistive signature possibly caused by groundwater discharge. Shallow anomalies observed in the GPR and ERT data were caused by near‐surface infrastructure and were consistent with anomalies observed in the FDEM data. Several parabolic reflectors were observed in the upper part of the GPR profiles, and a fairly continuous reflector that was interpreted as bedrock could be traced across the lower part of the profiles. MASW seismic data showed a sharp break in shear wave velocity at depth, which was interpreted as the overburden/bedrock interface. The MASW profile indicates the presence of a trough in the bedrock surface in the same location where the ERT data indicate lateral variations in resistivity. Depths to bedrock interpreted from the ERT, MASW, and GPR profiles were similar and consistent with the depths of refusal identified in the direct‐push wells. The interpretations of data collected using the individual methods yielded non‐unique solutions with considerable uncertainty. Integrated interpretation of the electrical, electromagnetic, and seismic geophysical profiles produced a more consistent and unique estimation of depth to bedrock that is consistent with ground‐truth data at the site. This test case shows that using

  19. 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...

  20. 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

  1. 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...

  2. Integrated geophysical investigations in a fault zone located on southwestern part of İzmir city, Western Anatolia, Turkey

    Science.gov (United States)

    Drahor, Mahmut G.; Berge, Meriç A.

    2017-01-01

    Integrated geophysical investigations consisting of joint application of various geophysical techniques have become a major tool of active tectonic investigations. The choice of integrated techniques depends on geological features, tectonic and fault characteristics of the study area, required resolution and penetration depth of used techniques and also financial supports. Therefore, fault geometry and offsets, sediment thickness and properties, features of folded strata and tectonic characteristics of near-surface sections of the subsurface could be thoroughly determined using integrated geophysical approaches. Although Ground Penetrating Radar (GPR), Electrical Resistivity Tomography (ERT) and Seismic Refraction Tomography (SRT) methods are commonly used in active tectonic investigations, other geophysical techniques will also contribute in obtaining of different properties in the complex geological environments of tectonically active sites. In this study, six different geophysical methods used to define faulting locations and characterizations around the study area. These are GPR, ERT, SRT, Very Low Frequency electromagnetic (VLF), magnetics and self-potential (SP). Overall integrated geophysical approaches used in this study gave us commonly important results about the near surface geological properties and faulting characteristics in the investigation area. After integrated interpretations of geophysical surveys, we determined an optimal trench location for paleoseismological studies. The main geological properties associated with faulting process obtained after trenching studies. In addition, geophysical results pointed out some indications concerning the active faulting mechanism in the area investigated. Consequently, the trenching studies indicate that the integrated approach of geophysical techniques applied on the fault problem reveals very useful and interpretative results in description of various properties of faulting zone in the investigation site.

  3. Archaeological Feedback as a Research Methodology in Near-Surface Geophysics

    Science.gov (United States)

    Maillol, J.; Ortega-Ramírez, J.; Berard, B.

    2005-05-01

    geophysical methods.

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

    Science.gov (United States)

    Eppelbaum, Lev

    2010-05-01

    It is obvious that noninvasive geophysical methods are the main interpreting tools at the areas of world recognized religious and cultural artifacts. Usually in these areas any excavations, drilling and infrastructure activity are forbidden or very strongly limited. According to field experience and results of numerous modeling (Eppelbaum, 1999, 2000, 2009a, 2009b; Eppelbaum and Itkis, 2001, 2003; Eppelbaum et al., 2000, 2001a, 2001b, 2003a, 2006a, 2006b, 2007, 2010, Itkis et al., 2003; Neishtadt et al., 2006), a set of applied geophysical methods may include the following types of surveys: (1) magnetic, (3) GPR (ground penetration radar), (3) gravity, (4) electromagnetic VLF (very low frequency), (5) ER (electric resistivity), (6) SP (self-potential), (7) IP (induced polarization), (8) SE (seismoelectric), and (9) NST (near-surface temperature). As it was shown in (Eppelbaum, 2005), interpretation ambiguity may be sufficiently reduced not only by integrated analysis of several geophysical methods, but also by the way of multilevel observations of geophysical fields. Magnetic, gravity and VLF measurements may be performed at different levels over the earth's surface (0.1 - 3 m), ER, SP and SE observations may be obtained with different depth of electrodes grounding (0.1 - 1 m), and NST sensor may be located at a depth of 0.8 - 2.5 m. GPR method usually allows measuring electromagnetic fields at various frequencies (with corresponding changing of the investigation depth and other parameters). Influence of some typical noise factors to geophysical investigations at archaeological sites was investigated in (Eppelbaum and Khesin, 2001). In many cases various constructions and walls are in the nearest vicinity of the examined artifacts. These constructions can be also utilized for carrying out geophysical measurements (magnetic, gravity and VLF) at different levels. Application of the modern ROV (remote operated vehicles) with registration of magnetic and VLF fields at

  5. 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

  6. Detection of Hazardous Cavities Below a Road Using Combined Geophysical Methods

    Science.gov (United States)

    De Giorgi, L.; Leucci, G.

    2014-07-01

    Assessment of the risk arising from near-surface natural hazard is a crucial step in safeguarding the security of the roads in karst areas. It helps authorities and other related parties to apply suitable procedures for ground treatment, mitigate potential natural hazards and minimize human and economic losses. Karstic terrains in the Salento Peninsula (Apulia region—South Italy) is a major challenge to engineering constructions and roads due to extensive occurrence of cavities and/or sinkholes that cause ground subsidence and both roads and building collapse. Cavities are air/sediment-filled underground voids, commonly developed in calcarenite sedimentary rocks by the infiltration of rainwater into the ground, opening up, over a long period of time, holes and tunnels. Mitigation of natural hazards can best be achieved through careful geoscientific studies. Traditionally, engineers use destructive probing techniques for the detection of cavities across regular grids or random distances. Such probing is insufficient on its own to provide confidence that cavities will not be encountered. Frequency of probing and depth of investigation may become more expensive. Besides, probing is intrusive, non-continuous, slow, expensive and cannot provide a complete lateral picture of the subsurface geology. Near-surface cavities usually can be easily detected by surface geophysical methods. Traditional and recently developed measuring techniques in seismic, geoelectrics and georadar are suitable for economical investigation of hazardous, potentially collapsing cavities. The presented research focused on an integrated geophysical survey that was carried out in a near-coast road located at Porto Cesareo, a small village a few kilometers south west of Lecce (south Italy). The roads in this area are intensively affected by dangerous surface cracks that cause structural instability. The survey aimed to image the shallow subsurface structures, including karstic features, and evaluate

  7. 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.

  8. 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

  9. Geophysics of Geothermal Areas: State of the Art and Future Development

    Science.gov (United States)

    Mabey, Don R.

    In May 1980 a workshop organized by the Advanced School of Geophysics of the Ettore Majorana Center for Scientific Culture was held in Erice, Italy. The purpose was to present the state of the art and future development of geophysics as related to exploration for geothermal resources and the environmental impact of the development of geothermal systems. The workshop was addressed to “younger researchers working in scientific institutions and in public or private agencies and who are particularly interested in these aspects of the energy problem.” Fourteen formal lectures were presented to the workshop. This volume contains papers based on 10 of these lectures with a preface, forward, and introduction by the editors. The ten papers are “Heat Transfer in Geothermal Areas,” “Interpretation of Conductive Heat Flow Anomalies,” “Deep Electromagnetic Soundings in Geothermal Exploration,” “A Computation Method for dc Geoelectric Fields,” “Measurement of Ground Deformation in Geothermal Areas,” “Active Seismic Methods in Geothermal Exploration,” “The Role of Geophysical Investigations in the Discovery of the Latera Geothermal Field,” “Geothermal Resources Exploration in the European Community: The Geophysical Case,” “Activity Performed by AGIP (ENI Group) in the Field of Geothermal Energy,” and “Geothermal Exploration in the Western United States.” Six of the authors are from Italy, and one each is from Iceland, the Netherlands, West Germany, and the United States. All of the papers are in English.

  10. Results from the University of Calgary environmental geophysics test range

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, K; Lawton, D.C.; Juigalli, J; Parry, D. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

    1995-12-31

    The Spy Hill Research Farm, operated by the University of Calgary as a test range site where geophysical equipment and methods related to environmental monitoring can be operated under controlled conditions, was described. The site is used by students in the geophysics courses offered at the University, but it is also intended to be available to other users for equipment tests. The site is underlain by glacial gravels and clays which reach thicknesses in excess of 30 m. Surveys of the site have been completed with the following geophysical systems: Geonics EM-31 and EM-34; Apex Max-Min; Huntec Mk4 IP with Phoenix IP-T1 transmitter; Geometrics Proton Magnetometer; McPhar vertical field Fluxgate magnetometer; Androtex TDR6 IP with Phoenix IP-T1 transmitter; Geometrics 12 channel refraction seismic system; and Pulse Echo Ground Penetrating Radar. The site has proved to be well suited to serve as a test range. The addition of yet more features to the site is being planned.

  11. 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

  12. 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

  13. Surface geophysical methods for characterising frozen ground in transitional permafrost landscapes

    Science.gov (United States)

    Briggs, Martin A.; Campbell, Seth; Nolan, Jay; Walvoord, Michelle Ann; Ntarlagiannis, Dimitrios; Day-Lewis, Frederick D.; Lane, John W.

    2017-01-01

    The distribution of shallow frozen ground is paramount to research in cold regions, and is subject to temporal and spatial changes influenced by climate, landscape disturbance and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically lacks the resolution to characterise finer-scale processes and phenomena, which are better captured by integrated surface geophysical methods. Here, we demonstrate the use of electrical resistivity imaging (ERI), electromagnetic induction (EMI), ground penetrating radar (GPR) and infrared imaging over multiple summer field seasons around the highly dynamic Twelvemile Lake, Yukon Flats, central Alaska, USA. Twelvemile Lake has generally receded in the past 30 yr, allowing permafrost aggradation in the receded margins, resulting in a mosaic of transient frozen ground adjacent to thick, older permafrost outside the original lakebed. ERI and EMI best evaluated the thickness of shallow, thin permafrost aggradation, which was not clear from frost probing or GPR surveys. GPR most precisely estimated the depth of the active layer, which forward electrical resistivity modelling indicated to be a difficult target for electrical methods, but could be more tractable in time-lapse mode. Infrared imaging of freshly dug soil pit walls captured active-layer thermal gradients at unprecedented resolution, which may be useful in calibrating emerging numerical models. GPR and EMI were able to cover landscape scales (several kilometres) efficiently, and new analysis software showcased here yields calibrated EMI data that reveal the complicated distribution of shallow permafrost in a transitional landscape.

  14. Geophysical investigation, Salmon Site, Lamar County, Mississippi

    International Nuclear Information System (INIS)

    1995-02-01

    Geophysical surveys were conducted in 1992 and 1993 on 21 sites at the Salmon Site (SS) located in Lamar County, Mississippi. The studies are part of the Remedial Investigation/Feasibility Study (RI/FS) being conducted by IT Corporation for the U.S. Department of Energy (DOE). During the 1960s, two nuclear devices and two chemical tests were detonated 826 meters (in) (2710 feet [ft]) below the ground surface in the salt dome underlying the SS. These tests were part of the Vela Uniform Program conducted to improve the United States capability to detect, identify, and locate underground nuclear detonations. The RI/FS is being conducted to determine if any contamination is migrating from the underground shot cavity in the salt dome and if there is any residual contamination in the near surface mud and debris disposal pits used during the testing activities. The objective of the surface geophysical surveys was to locate buried debris, disposal pits, and abandoned mud pits that may be present at the site. This information will then be used to identify the locations for test pits, cone penetrometer tests, and drill hole/monitor well installation. The disposal pits were used during the operation of the test site in the 1960s. Vertical magnetic gradient (magnetic gradient), electromagnetic (EM) conductivity, and ground-penetrating radar (GPR) surveys were used to accomplish these objectives. A description of the equipment used and a theoretical discussion of the geophysical methods are presented Appendix A. Because of the large number of figures relative to the number of pages of text, the geophysical grid-location maps, the contour maps of the magnetic-gradient data, the contour maps of the EM conductivity data, and the GPR traverse location maps are located in Appendix B, Tabs I through 22. In addition, selected GPR records are located in Appendix C

  15. SIGKit: a New Data-based Software for Learning Introductory Geophysics

    Science.gov (United States)

    Zhang, Y.; Kruse, S.; George, O.; Esmaeili, S.; Papadimitrios, K. S.; Bank, C. G.; Cadmus, A.; Kenneally, N.; Patton, K.; Brusher, J.

    2016-12-01

    Students of diverse academic backgrounds take introductory geophysics courses to learn the theory of a variety of measurement and analysis methods with the expectation to be able to apply their basic knowledge to real data. Ideally, such data is collected in field courses and also used in lecture-based courses because they provide a critical context for better learning and understanding of geophysical methods. Each method requires a separate software package for the data processing steps, and the complexity and variety of professional software makes the path through data processing to data interpretation a strenuous learning process for students and a challenging teaching task for instructors. SIGKit (Student Investigation of Geophysics Toolkit) being developed as a collaboration between the University of South Florida, the University of Toronto, and MathWorks intends to address these shortcomings by showing the most essential processing steps and allowing students to visualize the underlying physics of the various methods. It is based on MATLAB software and offered as an easy-to-use graphical user interface and packaged so it can run as an executable in the classroom and the field even on computers without MATLAB licenses. An evaluation of the software based on student feedback from focus-group interviews and think-aloud observations helps drive its development and refinement. The toolkit provides a logical gateway into the more sophisticated and costly software students will encounter later in their training and careers by combining essential visualization, modeling, processing, and analysis steps for seismic, GPR, magnetics, gravity, resistivity, and electromagnetic data.

  16. Geophysical techniques used in uranium exploration

    International Nuclear Information System (INIS)

    Meyer, P.A.

    1977-01-01

    The impetus in uranium exploration has been generated by the increase in price to about $40.00 a pound or $2.50 an ounce, a price that approaches a precious metal. Not only has the search increased in the traditional sandstone areas, but also in the igneous and metamorphic environments. Because uranium is one of the elements along with thorium and potassium that radiate alpha, beta and gamma rays; direct methods have been developed and improved upon to measure this radiation while indirect traditional geophysical methods have been used to assist in locating associated favorable structural and ''stratigraphic'' zones

  17. Archaeological Geophysics in Israel: Past, Present and Future

    Science.gov (United States)

    Eppelbaum, L. V.

    2009-04-01

    Israel is a country with diverse and rapidly changeable environments where is localized a giant number of archaeological objects of various age, origin and size. The archaeological remains occur in a complex (multi-layered and variable) geological-archaeological media. It is obvious that direct archaeological excavations cannot be employed at all localized and supposed sites taking into account the financial, organizational, ecological and other reasons. Therefore, for delineation of buried archaeological objects, determination their physical-geometrical characteristics and classification, different geophysical methods are widely applied. The number of employed geophysical methodologies is constantly increasing and now Israeli territory may be considered as a peculiar polygon for various geophysical methods testing. The geophysical investigations at archaeological sites in Israel could be tentatively divided on three stages: (1) past [- 1990] (e.g., Batey, 1987; Ben-Menahem, 1979; Dolphin, 1981; Ginzburg and Levanon, 1977; Karcz et al., 1977; Karcz and Kafri, 1978; Tanzi et al., 1983; Shalem, 1949; Willis, 1928), (2) present [1991 - 2008] (e.g., Bauman et al., 2005; Ben-Dor et al., 1999; Ben-Yosef et al., 2008; Berkovitch et al., 2000; Borradaile, 2003; Boyce et al., 2004; Bruins et al., 2003; Daniels et al., 2003; Ellenblum et al., 1998; Eppelbaum, 1999, 2000a, 2000b, 2005, 2007a, 2007b, 2008b; Eppelbaum and Ben-Avraham, 2002; Eppelbaum and Itkis, 2000, 2001; 2003, 2009; Eppelbaum et al., 2000a, 2000b, 2001a, 2001b, 2003a, 2003b, 2004a, 2004b; 2005, 2006a, 2006b, 2006c, 2006d, 2007, 2009a, 2009b; Ezersky et al., 2000; Frumkin et al., 2003; Itkis and Eppelbaum, 1998; Itkis, 2003; Itkis et al., 2002, 2003, 2008; Jol et al., 2003, 2008; Kamai and Hatzor, 2007; Khesin et al., 1996; Korjenkov and Mazor, 1999; Laukin et al., 2001; McDermott et al., 1993; Marco, 2008; Marco et al., 2003; Nahas et al., 2006; Neishtadt et al., 2006; Nur and Ron, 1997; Paparo, 1991; Porat

  18. Quantitative geological modeling based on probabilistic integration of geological and geophysical data

    DEFF Research Database (Denmark)

    Gulbrandsen, Mats Lundh

    In order to obtain an adequate geological model of any kind, proper integration of geophysical data, borehole logs and geological expert knowledge is important. Geophysical data provide indirect information about geology, borehole logs provide sparse point wise direct information about geology...... entitled Smart Interpretation is developed. This semi-automatic method learns the relation between a set of data attributes extracted from deterministically inverted airborne electromagnetic data and a set of interpretations of a geological layer that is manually picked by a geological expert...

  19. Fundamentals of Geophysics

    Science.gov (United States)

    Frohlich, Cliff

    Choosing an intermediate-level geophysics text is always problematic: What should we teach students after they have had introductory courses in geology, math, and physics, but little else? Fundamentals of Geophysics is aimed specifically at these intermediate-level students, and the author's stated approach is to construct a text “using abundant diagrams, a simplified mathematical treatment, and equations in which the student can follow each derivation step-by-step.” Moreover, for Lowrie, the Earth is round, not flat—the “fundamentals of geophysics” here are the essential properties of our Earth the planet, rather than useful techniques for finding oil and minerals. Thus this book is comparable in both level and approach to C. M. R. Fowler's The Solid Earth (Cambridge University Press, 1990).

  20. Leachate recirculation: moisture content assessment by means of a geophysical technique.

    Science.gov (United States)

    Guérin, Roger; Munoz, Marie Laure; Aran, Christophe; Laperrelle, Claire; Hidra, Mustapha; Drouart, Eric; Grellier, Solenne

    2004-01-01

    Bioreactor technology is a waste treatment concept consisting in speeding up the biodegradation of landfilled waste by optimizing its moisture content through leachate recirculation. The measurement of variations in waste moisture content is critical in the design and control of bioreactors. Conventional methods such as direct physical sampling of waste reach their limits due to the interference with the waste matrix. This paper reviews geophysical measurements such as electrical direct current and electromagnetic slingram methods for measuring the electrical conductivity. Electrical conductivity is a property, which is linked to both moisture and temperature and can provide useful indications on the biodegradation environment in the waste mass. The study reviews three site experiments: a first experimentation shows the advantages (correlation between conductive anomaly and water seepage) but also the limits of geophysical interpretation; the two other sites allow the leachate recirculation to be tracked by studying the relative resistivity variation versus time from electrical 2D imaging. Even if some improvements are necessary to consider geophysical measurements as a real bioreactor monitoring tool, results are promising and could lead to the use of electrical 2D imaging in bioreactor designing.

  1. Estimating climate resilience for conservation across geophysical settings.

    Science.gov (United States)

    Anderson, Mark G; Clark, Melissa; Sheldon, Arlene Olivero

    2014-08-01

    Conservationists need methods to conserve biological diversity while allowing species and communities to rearrange in response to a changing climate. We developed and tested such a method for northeastern North America that we based on physical features associated with ecological diversity and site resilience to climate change. We comprehensively mapped 30 distinct geophysical settings based on geology and elevation. Within each geophysical setting, we identified sites that were both connected by natural cover and that had relatively more microclimates indicated by diverse topography and elevation gradients. We did this by scoring every 405 ha hexagon in the region for these two characteristics and selecting those that scored >SD 0.5 above the mean combined score for each setting. We hypothesized that these high-scoring sites had the greatest resilience to climate change, and we compared them with sites selected by The Nature Conservancy for their high-quality rare species populations and natural community occurrences. High-scoring sites captured significantly more of the biodiversity sites than expected by chance (p < 0.0001): 75% of the 414 target species, 49% of the 4592 target species locations, and 53% of the 2170 target community locations. Calcareous bedrock, coarse sand, and fine silt settings scored markedly lower for estimated resilience and had low levels of permanent land protection (average 7%). Because our method identifies-for every geophysical setting-sites that are the most likely to retain species and functions longer under a changing climate, it reveals natural strongholds for future conservation that would also capture substantial existing biodiversity and correct the bias in current secured lands. © 2014 The Authors. Conservation Biology published by Wiley Periodicals, Inc., on behalf of the Society for Conservation Biology.

  2. Rapid estimation of aquifer salinity structure from oil and gas geophysical logs

    Science.gov (United States)

    Shimabukuro, D.; Stephens, M.; Ducart, A.; Skinner, S. M.

    2016-12-01

    We describe a workflow for creating aquifer salinity maps using Archie's equation for areas that have geophysical data from oil and gas wells. We apply this method in California, where geophysical logs are available in raster format from the Division of Oil, Gas, and Geothermal Resource (DOGGR) online archive. This method should be applicable to any region where geophysical logs are readily available. Much of the work is controlled by computer code, allowing salinity estimates for new areas to be rapidly generated. For a region of interest, the DOGGR online database is scraped for wells that were logged with multi-tool suites, such as the Platform Express or Triple Combination Logging Tools. Then, well construction metadata, such as measured depth, spud date, and well orientation, is attached. The resultant local database allows a weighted criteria selection of wells that are most likely to have the shallow resistivity, deep resistivity, and density porosity measurements necessary to calculate salinity over the longest depth interval. The algorithm can be adjusted for geophysical log availability for older well fields and density of sampling. Once priority wells are identified, a student researcher team uses Neuralog software to digitize the raster geophysical logs. Total dissolved solid (TDS) concentration is then calculated in clean, wet sand intervals using the resistivity-porosity method, a modified form of Archie's equation. These sand intervals are automatically selected using a combination of spontaneous potential and the difference in shallow resistivity and deep resistivity measurements. Gamma ray logs are not used because arkosic sands common in California make it difficult to distinguish sand and shale. Computer calculation allows easy adjustment of Archie's parameters. The result is a semi-continuous TDS profile for the wells of interest. These profiles are combined and contoured using standard 3-d visualization software to yield preliminary salinity

  3. Environmental and regulatory considerations when planning a geophysical program

    International Nuclear Information System (INIS)

    Down-Cicoria, C.

    1999-01-01

    Public concerns regarding the environmental impact of geophysical programs have resulted in more pressure on the federal and provincial governments to regulate and protect unique ecosites. In the past decade, about 1 million kilometres of seismic have been shot by the petroleum industry in Alberta alone, representing about 70,000 hectares of land base. This paper reviewed how a preliminary assessment of any geophysical project should consider the effects of all projects on the terrain, climate, vegetation, soils, fisheries, wildlife, aquatic ecosystems, heritage resources, and timber dispositions. Geo-administrative boundaries, field assessments, environmental assessments and mitigation measures such as low impact line cutting methods, timing methods, and heli-portable operations must also be considered. Special considerations when planning a three-dimensional program were highlighted. Certain equipment suitable as mitigation measures such as mulchers, hydro-axes, enviro-drills, biodegradable lathes, tracked/low PSI equipment, and doglegs were also reviewed. 15 refs., 2 tabs., 18 figs

  4. Marine geophysical data management and presentation system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.

    ) of the National Institute of Oceanography, Goa, India. GPDMPS is designed for the computerized storage retrieval and presentation of marine geophysical data and information. For the systematic management of geophysical data and information, GPDMPS is subdivided...

  5. 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

  6. 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

  7. Fusion of Geophysical Images in the Study of Archaeological Sites

    Science.gov (United States)

    Karamitrou, A. A.; Petrou, M.; Tsokas, G. N.

    2011-12-01

    This paper presents results from different fusion techniques between geophysical images from different modalities in order to combine them into one image with higher information content than the two original images independently. The resultant image will be useful for the detection and mapping of buried archaeological relics. The examined archaeological area is situated in Kampana site (NE Greece) near the ancient theater of Maronia city. Archaeological excavations revealed an ancient theater, an aristocratic house and the temple of the ancient Greek God Dionysus. Numerous ceramic objects found in the broader area indicated the probability of the existence of buried urban structure. In order to accurately locate and map the latter, geophysical measurements performed with the use of the magnetic method (vertical gradient of the magnetic field) and of the electrical method (apparent resistivity). We performed a semi-stochastic pixel based registration method between the geophysical images in order to fine register them by correcting their local spatial offsets produced by the use of hand held devices. After this procedure we applied to the registered images three different fusion approaches. Image fusion is a relatively new technique that not only allows integration of different information sources, but also takes advantage of the spatial and spectral resolution as well as the orientation characteristics of each image. We have used three different fusion techniques, fusion with mean values, with wavelets by enhancing selected frequency bands and curvelets giving emphasis at specific bands and angles (according the expecting orientation of the relics). In all three cases the fused images gave significantly better results than each of the original geophysical images separately. The comparison of the results of the three different approaches showed that the fusion with the use of curvelets, giving emphasis at the features' orientation, seems to give the best fused image

  8. Assessment of multiple geophysical techniques for the characterization of municipal waste deposit sites

    Science.gov (United States)

    Gaël, Dumont; Tanguy, Robert; Nicolas, Marck; Frédéric, Nguyen

    2017-10-01

    In this study, we tested the ability of geophysical methods to characterize a large technical landfill installed in a former sand quarry. The geophysical surveys specifically aimed at delimitating the deposit site horizontal extension, at estimating its thickness and at characterizing the waste material composition (the moisture content in the present case). The site delimitation was conducted with electromagnetic (in-phase and out-of-phase) and magnetic (vertical gradient and total field) methods that clearly showed the transition between the waste deposit and the host formation. Regarding waste deposit thickness evaluation, electrical resistivity tomography appeared inefficient on this particularly thick deposit site. Thus, we propose a combination of horizontal to vertical noise spectral ratio (HVNSR) and multichannel analysis of the surface waves (MASW), which successfully determined the approximate waste deposit thickness in our test landfill. However, ERT appeared to be an appropriate tool to characterize the moisture content of the waste, which is of prior information for the organic waste biodegradation process. The global multi-scale and multi-method geophysical survey offers precious information for site rehabilitation studies, water content mitigation processes for enhanced biodegradation or landfill mining operation planning.

  9. 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...

  10. A general framework of TOPSIS method for integration of airborne geophysics, satellite imagery, geochemical and geological data

    Science.gov (United States)

    Abedi, Maysam; Norouzi, Gholam-Hossain

    2016-04-01

    This work presents the promising application of three variants of TOPSIS method (namely the conventional, adjusted and modified versions) as a straightforward knowledge-driven technique in multi criteria decision making processes for data fusion of a broad exploratory geo-dataset in mineral potential/prospectivity mapping. The method is implemented to airborne geophysical data (e.g. potassium radiometry, aeromagnetic and frequency domain electromagnetic data), surface geological layers (fault and host rock zones), extracted alteration layers from remote sensing satellite imagery data, and five evidential attributes from stream sediment geochemical data. The central Iranian volcanic-sedimentary belt in Kerman province at the SE of Iran that is embedded in the Urumieh-Dokhtar Magmatic Assemblage arc (UDMA) is chosen to integrate broad evidential layers in the region of prospect. The studied area has high potential of ore mineral occurrences especially porphyry copper/molybdenum and the generated mineral potential maps aim to outline new prospect zones for further investigation in future. Two evidential layers of the downward continued aeromagnetic data and its analytic signal filter are prepared to be incorporated in fusion process as geophysical plausible footprints of the porphyry type mineralization. The low values of the apparent resistivity layer calculated from the airborne frequency domain electromagnetic data are also used as an electrical criterion in this investigation. Four remote sensing evidential layers of argillic, phyllic, propylitic and hydroxyl alterations were extracted from ASTER images in order to map the altered areas associated with porphyry type deposits, whilst the ETM+ satellite imagery data were used as well to map iron oxide layer. Since potassium alteration is generally the mainstay of porphyry ore mineralization, the airborne potassium radiometry data was used. The geochemical layers of Cu/B/Pb/Zn elements and the first component of PCA

  11. 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

  12. Quantitative Analysis of Piezoelectric and Seismoelectric Anomalies in Subsurface Geophysics

    Science.gov (United States)

    Eppelbaum, Lev

    2017-04-01

    The piezoelectric and seismo-electrokinetic phenomena are manifested by electrical and electromagnetic processes that occur in rocks under the influence of elastic oscillations triggered by shots or mechanical impacts (hits) (e.g., Neishtadt and Osipov, 1958; Neishtadt, 1961; Parkhomenko, 1971; Neishtadt et al., 1986; Maxwell et al., 1992; Butler et al., 1994; Kepic et al., 1995; Neishtadt et al., 1996; Mikhalov et al., 1997; Boulytchov, 2000; Dupuis et al., 2009; Schakel et al., 2011; Neishtadt and Eppelbaum, 2012; Jouniaux and Zyserman, 2016). The developed classification divides the above phenomena into the following types: (1) the seismo-electrokinetic (electrokinetic) phenomenon E, which occurs in polyphase media due to the mutual displacement of the solid and liquid phases; (2) the piezoelectric phenomenon, which occurs in rocks that contain piezoactive minerals; (3) the shot-triggered phenomenon, which is observed in rocks in the vicinity of a shot or hit point; (4) the seismoelectric phenomenon I, manifested by the change of the electric current passing through rocks, and (5) high-frequency impulse electromagnetic radiation, which is generated by massive base-metal bodies. This paper describes the above phenomena in detail, describing their nature, manifestation patterns, and registration techniques. Because the manifestation patterns of the above phenomena are different in different rocks, these phenomena can be used as a basis for geophysical exploration techniques. The piezoelectric method is an example of a successful application of piezoelectric and seismo-electrokinetic phenomena in exploration geophysics. It has been successfully applied in mineral exploration and environmental features research in Russia, USA, Canada, Australia, Belorussia, Azerbaijan, Georgia, Israel and other countries. This method uses comparatively new geophysical parameter - piezoelectric activity of rocks, ores, and minerals. It enables direct exploration for pegmatite

  13. Methods and applications of radio frequency geophysics in glaciology

    Science.gov (United States)

    Holschuh, Nicholas

    Simple radar systems of the past were used primarily for radar depth sounding, the process of using reflection travel times and electromagnetic velocities to determine the ice thickness. Modern radioglaciology uses both the travel times and reflection amplitudes to make inferences about the englacial and subglacial environments; however, non-uniqueness in geophysical data, combined with the large number of physical parameters that control reflection amplitude, have led to significant uncertainties in this type of analysis. In this set of studies, I improve on data collection, processing, and assimilation methods, with a focus on radar reflection amplitudes and internal layers. The first two studies are devoted to radar survey methods, in which I examine the impact of reflector geometry on amplitude (2), and investigate an independent measure of radar attenuation using variable-offset data, in an effort to eliminate the effects of ice chemistry and temperature on reflection amplitudes (3). These studies emphasize the fact that radar data are a product of both the physical system and the imaging process, and caution glaciologists from over-interpreting processing artifacts common in radar data collected in areas of complex glacial flow. In the following two chapters, I go on to provide glaciological applications of processed radar data, interpreting the record of complex flow left behind in englacial reflector slopes (4), and applying improved boundary conditions to better predict the maximum extent of West Antarctic collapse (5). These studies use geometric information from the bed reflector and englacial reflectors to describe the flow regime present in Antarctica today. Chapter 4 examines how boundary conditions that are difficult to observe directly (the geothermal heat flux, as well as the frictional and deformation characteristics of the ice-sheet substrate) manifest through internal layer deformation. Chapter 5 focuses on Marie Byrd Land (MBL), where

  14. The innovative application of surface geophysical techniques for remedial investigations

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, W.R. [OYO Geospace, Fort Myers, FL (United States); Smith, S. [ICF Kaiser Engineers, Boston, MA (United States); Gilmore, P. [Fishbeck, Thomson, Carr and Huber, Aida, MI (United States); Cox, S. [Blasland, Bouck, and Lee, Edison, NJ (United States)

    1993-03-01

    When researchers are investigating potential subsurface contamination at hazardous waste landfills, the surface geophysical techniques they may use are often limited. Many geophysical surveys are concerned with areas next to and not directly within the landfill units. The highly variable properties of the materials within the landfill may result in geophysical data that are either difficult or impossible to interpret. Therefore, contamination at these sites may not be detected until substantial lateral migration away from the unit has occurred. In addition, because of the poor resolution of some techniques, the landfill as a whole must be considered as a source, where discrete disposal areas within landfill units may be the actual point sources of contaminants. In theory, if specific sources within the landfill are identified and isolated, then reduced time, effort, and expenditures will be required for remediation activities. In the summer of 1989, the Idaho National Engineering Laboratory (INEL) investigated a small potentially hazardous waste landfill to determine if contaminant hot spots could be identified within the landfill and to determine if significant vertical and lateral migration of contaminants was occurring away from these locations. Based on the present hydrogeologic conditions, researchers anticipated that subsurface flow would be primarily vertical, with the zone of saturation at a depth greater than 150 meters. This necessitated that the survey be performed, for the most part, directly on the capped portion of the landfill. Focused geophysical surveys conducted off the landfill would not have provided useful information concerning conditions directly beneath the landfill. This paper discusses the planning, application, and analysis of four combined sensing methods: two methods of electromagnetic induction [low induction (Em) and time domain (TEM)], ground penetrating radar (GPR), and soil gas.

  15. Multivariate time series clustering on geophysical data recorded at Mt. Etna from 1996 to 2003

    Science.gov (United States)

    Di Salvo, Roberto; Montalto, Placido; Nunnari, Giuseppe; Neri, Marco; Puglisi, Giuseppe

    2013-02-01

    Time series clustering is an important task in data analysis issues in order to extract implicit, previously unknown, and potentially useful information from a large collection of data. Finding useful similar trends in multivariate time series represents a challenge in several areas including geophysics environment research. While traditional time series analysis methods deal only with univariate time series, multivariate time series analysis is a more suitable approach in the field of research where different kinds of data are available. Moreover, the conventional time series clustering techniques do not provide desired results for geophysical datasets due to the huge amount of data whose sampling rate is different according to the nature of signal. In this paper, a novel approach concerning geophysical multivariate time series clustering is proposed using dynamic time series segmentation and Self Organizing Maps techniques. This method allows finding coupling among trends of different geophysical data recorded from monitoring networks at Mt. Etna spanning from 1996 to 2003, when the transition from summit eruptions to flank eruptions occurred. This information can be used to carry out a more careful evaluation of the state of volcano and to define potential hazard assessment at Mt. Etna.

  16. Resistivity method contribution in determining of fault zone and hydro-geophysical characteristics of carbonate aquifer, eastern desert, Egypt

    Science.gov (United States)

    Ammar, A. I.; Kamal, K. A.

    2018-03-01

    Determination of fault zone and hydro-geophysical characteristics of the fractured aquifers are complicated, because their fractures are controlled by different factors. Therefore, 60 VESs were carried out as well as 17 productive wells for determining the locations of the fault zones and the characteristics of the carbonate aquifer at the eastern desert, Egypt. The general curve type of the recorded rock units was QKH. These curves were used in delineating the zones of faults according to the application of the new assumptions. The main aquifer was included at end of the K-curve type and front of the H-curve type. The subsurface layers classified into seven different geoelectric layers. The fractured shaly limestone and fractured limestone layers were the main aquifer and their resistivity changed from low to medium (11-93 Ω m). The hydro-geophysical properties of this aquifer such as the areas of very high, high, and intermediate fracture densities of high groundwater accumulations, salinity, shale content, porosity distribution, and recharging and flowing of groundwater were determined. The statistical analysis appeared that depending of aquifer resistivity on the water salinities (T.D.S.) and water resistivities add to the fracture density and shale content. The T.D.S. increasing were controlled by Na+, Cl-, Ca2+, Mg2+, and then (SO4)2-, respectively. The porosity was calculated and its average value was 19%. The hydrochemical analysis of groundwater appeared that its type was brackish and the arrangements of cation concentrations were Na+ > Ca2+ > Mg2+ > K+ and anion concentrations were Cl- > (SO4)2- > HCO3 - > CO3 -. The groundwater was characterized by sodium-bicarbonate and sodium-sulfate genetic water types and meteoric in origin. Hence, it can use the DC-resistivity method in delineating the fault zone and determining the hydro-geophysical characteristics of the fractured aquifer with taking into account the quality of measurements and interpretation.

  17. Site characterization and validation - geophysical single hole logging. Stage 1

    International Nuclear Information System (INIS)

    Fridh, B.

    1987-12-01

    Five 'boundary boreholes' have been drilled for preliminary characterization of a previously unexplored site at the 360 m level in the Stripa mine. Three of these boreholes are directed towards the North in the mine coordinate system, while two are directed towards the West. Furthermore, a vertical hole has been drilled at the end of the 3D-migration drift. To adequately describe the rock mass in the vicinity of these boreholes, a comprehensive program utilizing a large number of geophysical borehole methods has been carried out. The specific geophysical character of the rock mass and the major deformed units distinguished in the boreholes are recognized, and in certain cases also correlated between the boreholes. (orig.)

  18. 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

    earthquake rupture; SNAC, a developing 3-D coded based on the FLAC method for visco-elastoplastic deformation; SNARK, a 3-D FE-PIC method for viscoplastic deformation; and gPLATES an open source paleogeographic/plate tectonics modeling package. We will demonstrate how codes can be linked with themselves, such as a regional and global model of mantle convection and a visco-elastoplastic representation of the crust within viscous mantle flow. Finally, we will describe how http://GeoFramework.org has become a distribution site for a suite of modeling software in geophysics.

  19. 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

  20. 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

  1. 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

    rocks. Details of how the shallow and deep components interact and mechanisms causing these interactions remain unknown, but the data demonstrate the usefulness of obtaining Sr-isotope data from future sample campaigns. Geophysical methods that would be useful for characterization of the UGB subsurface properties and geothermal system include electromagnetic (EM), gravity, and ambient seismic. A suite of ground-based EM methods could be used in a synergistic combination together with airborne EM surveys to provide data for a range of spatial scales and resolutions. Existing thermal data for the shallow subsurface could be used to relate ground and airborne EM survey data to locations of geothermal fluids near the surface. Gravity surveys would be useful for mapping subsurface density anomalies and possibly monitoring changes in degree of saturation with groundwater. Ambient seismic surveys would be useful for estimating the thickness of unconsolidated deposits that contain the shallow groundwater system. A study that combines radiogenic isotope tracers with geophysical methods has the potential to better characterize the geothermal workings in the UGB. Insights gained could lead to a better understanding of the geothermal system and how Park infrastructure may cause perturbations. Measurements of radiogenic isotopes from multiple geysers and pools in localized areas within the UGB that are coupled with data from geophysical surveys would help refine conceptual models of mixing between deep- and shallow-derived subsurface fluids.

  2. 3D geophysical inversion for contact surfaces

    Science.gov (United States)

    Lelièvre, Peter; Farquharson, Colin

    2014-05-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. In contrast, standard minimum-structure volumetric inversions (performed on meshes of space-filling cells) recover smooth models inconsistent with such interpretations. There are several approaches through which geophysical inversion can help recover models with the desired characteristics. Some authors have developed iterative strategies in which several volumetric inversions are performed with regularization parameters changing to achieve sharper interfaces at automatically determined locations. Another approach is to redesign the regularization to be consistent with the desired model characteristics, e.g. L1-like norms or compactness measures. A few researchers have taken approaches that limit the recovered values to lie within particular ranges, resulting in sharp discontinuities; these include binary inversion, level set methods and clustering strategies. In most of the approaches mentioned above, the model parameterization considers the physical properties in each of the many space-filling cells within the volume of interest. The exception are level set methods, in which a higher dimensional function is parameterized and the contact surface is determined from the zero-level of that function. However, even level-set methods rely on an underlying volumetric mesh. We are researching a fundamentally different type of inversion that parameterizes the Earth in terms of the contact surfaces between rock units. 3D geological Earth models typically comprise wireframe surfaces of tessellated triangles or other polygonal planar facets. This wireframe representation allows for flexible and efficient generation of complicated geological structures. Therefore, a natural approach for representing a geophysical model in an inversion is to parameterize the wireframe contact surfaces as the coordinates of the nodes (facet vertices). The geological and

  3. Geophysical data fusion for subsurface imaging

    International Nuclear Information System (INIS)

    Hoekstra, P.; Vandergraft, J.; Blohm, M.; Porter, D.

    1993-08-01

    A geophysical data fusion methodology is under development to combine data from complementary geophysical sensors and incorporate geophysical understanding to obtain three dimensional images of the subsurface. The research reported here is the first phase of a three phase project. The project focuses on the characterization of thin clay lenses (aquitards) in a highly stratified sand and clay coastal geology to depths of up to 300 feet. The sensor suite used in this work includes time-domain electromagnetic induction (TDEM) and near surface seismic techniques. During this first phase of the project, enhancements to the acquisition and processing of TDEM data were studied, by use of simulated data, to assess improvements for the detection of thin clay layers. Secondly, studies were made of the use of compressional wave and shear wave seismic reflection data by using state-of-the-art high frequency vibrator technology. Finally, a newly developed processing technique, called ''data fusion,'' was implemented to process the geophysical data, and to incorporate a mathematical model of the subsurface strata. Examples are given of the results when applied to real seismic data collected at Hanford, WA, and for simulated data based on the geology of the Savannah River Site

  4. Geophysical anomalies associated with uranium mineralization from Beldih mine, South Purulia Shear Zone, India

    International Nuclear Information System (INIS)

    Mandal, Animesh; Biswas, Arkoprovo; Mittal, Saurabh; Mohanty, William K.; Sharma, Shashi Prakash; Sengupta, Debashish; Sen, Joydip; Bhatt, A.K.

    2013-01-01

    Beldih mine at the central part of the South Purulia Shear Zone (SPSZ) has been reported with low grade uranium-bearing formation within quartz-magnetite-apatite host in kaolinized formation. Therefore, the present integrated geophysical study with gravity, magnetic, radiometric, very low frequency electromagnetic (VLF) and gradient resistivity profiling methods around the known mineralized zones aimed at identifying the exact geophysical signatures and lateral extent of these uranium mineralization bands. The closely spaced gravity-magnetic contours over the low to high anomaly transition zones of Bouguer, reduced-to-pole magnetic, and trend surface separated residual gravity-magnetic anomaly maps indicate the possibility of high altered zone(s) along NW-SE direction at the central part of the study area. High current density plots of VLF method and the low resistive zones in gradient resistivity study depict the coincidence with low gravity, moderately high magnetic and low resistivity anomalies at the same locations. Moderate high radioactive zones have also been observed over these locations. This also suggests the existence of radioactive mineralization over this region. Along profile P2, drilled borehole data revealed the presence of uranium mineralization at a depth of ∼100 m. The vertical projection of this mineralization band also identified as low gravity, low resistivity and high magnetic anomaly zone. Thus, the application of integrated geophysical techniques supported by geological information successfully recognized the nature of geophysical signatures associated with the uranium mineralization of this region. This enhances the scope of further integrated geophysical investigations in the unexplored regions of SPSZ. (author)

  5. Detecting Buried Archaeological Remains by the Use of Geophysical Data Processing with 'Diffusion Maps' Methodology

    Science.gov (United States)

    Eppelbaum, Lev

    2015-04-01

    Geophysical methods are prompt, non-invasive and low-cost tool for quantitative delineation of buried archaeological targets. However, taking into account the complexity of geological-archaeological media, some unfavourable environments and known ambiguity of geophysical data analysis, a single geophysical method examination might be insufficient (Khesin and Eppelbaum, 1997). Besides this, it is well-known that the majority of inverse-problem solutions in geophysics are ill-posed (e.g., Zhdanov, 2002), which means, according to Hadamard (1902), that the solution does not exist, or is not unique, or is not a continuous function of observed geophysical data (when small perturbations in the observations will cause arbitrary mistakes in the solution). This fact has a wide application for informational, probabilistic and wavelet methodologies in archaeological geophysics (Eppelbaum, 2014a). The goal of the modern geophysical data examination is to detect the geophysical signatures of buried targets at noisy areas via the analysis of some physical parameters with a minimal number of false alarms and miss-detections (Eppelbaum et al., 2011; Eppelbaum, 2014b). The proposed wavelet approach to recognition of archaeological targets (AT) by the examination of geophysical method integration consists of advanced processing of each geophysical method and nonconventional integration of different geophysical methods between themselves. The recently developed technique of diffusion clustering combined with the abovementioned wavelet methods was utilized to integrate the geophysical data and detect existing irregularities. The approach is based on the wavelet packet techniques applied as to the geophysical images (or graphs) versus coordinates. For such an analysis may be utilized practically all geophysical methods (magnetic, gravity, seismic, GPR, ERT, self-potential, etc.). On the first stage of the proposed investigation a few tens of typical physical-archaeological models (PAM

  6. The potential of near-surface geophysical methods in a hierarchical monitoring approach for the detection of shallow CO2 seeps at geological storage sites

    Science.gov (United States)

    Sauer, U.; Schuetze, C.; Dietrich, P.

    2013-12-01

    The MONACO project (Monitoring approach for geological CO2 storage sites using a hierarchic observation concept) aims to find reliable monitoring tools that work on different spatial and temporal scales at geological CO2 storage sites. This integrative hierarchical monitoring approach based on different levels of coverage and resolutions is proposed as a means of reliably detecting CO2 degassing areas at ground surface level and for identifying CO2 leakages from storage formations into the shallow subsurface, as well as CO2 releases into the atmosphere. As part of this integrative hierarchical monitoring concept, several methods and technologies from ground-based remote sensing (Open-path Fourier-transform infrared (OP-FTIR) spectroscopy), regional measurements (near-surface geophysics, chamber-based soil CO2 flux measurement) and local in-situ measurements (using shallow boreholes) will either be combined or used complementary to one another. The proposed combination is a suitable concept for investigating CO2 release sites. This also presents the possibility of adopting a modular monitoring concept whereby our monitoring approach can be expanded to incorporate other methods in various coverage scales at any temporal resolution. The link between information obtained from large-scale surveys and local in-situ monitoring can be realized by sufficient geophysical techniques for meso-scale monitoring, such as geoelectrical and self-potential (SP) surveys. These methods are useful for characterizing fluid flow and transport processes in permeable near-surface sedimentary layers and can yield important information concerning CO2-affected subsurface structures. Results of measurements carried out a natural analogue site in the Czech Republic indicate that the hierarchical monitoring approach represents a successful multidisciplinary modular concept that can be used to monitor both physical and chemical processes taking place during CO2 migration and seepage. The

  7. Analysis of neotectonic structures in the Eastern Precordillera of Argentina in relation to seismic hazard by the application of integrated geophysical methods

    Science.gov (United States)

    Correa-Otto, Sebastián; Ariza, Juan; Lince Klinger, Federico; Giménez, Mario; López Hidalgo, Andrés

    2018-03-01

    The city of San Juan, in the Central-Western region of Argentina, has been the target of very destructive superficial earthquakes, some of which have not been associated to a clear structural source up to this date. The city is constantly growing outside the valley where it is located, towards the area of Eastern Precordillera which is currently having an increased socio-cultural activity. Thus, this study is focused on increasing the geological knowledge of the latter by studying the eastern flank of Sierra Chica de Zonda (Eastern Precordillera) whose proved neotectonic activity represents a geohazard. On the basis of the general geological setting the neotectonic structures in the study area are related to a major active synclinal folding located just under the western sector of the San Juan city. Geophysical potential methods (gravimetric and magnetometric surveys) were used to recognize contacts by contrast of density and magnetic susceptibility. In order to reduce the ambiguity of these methods the gravi-magnetometric results were constrained by using seismic and electrical tomographies. These contacts where geophysical properties abruptly change, were interpreted as faults despite many of them not having a superficial expression. The latter being of great importance to asses the seismic hazard of the study area.

  8. Muon tomography of the Soufrière of Guadeloupe (Lesser Antilles): Comparison with other geophysical imaging methods and assessment of volcanic risks

    Science.gov (United States)

    Gibert, D.; Lesparre, N.; Marteau, J.; Taisne, B.; Nicollin, F.; Coutant, O.

    2011-12-01

    adapted to brought constraints on flank destabilization and hydrothermal circulation models. Tanaka et al., Three dimensional computational axial tomography scan of a volcano with cosmic ray muon radiography, J. Geophys. Res., 115, B12332, doi:10.1029/2010JB007677, 2010. Gibert et al., Muon Tomography: Plans for Observations in the Lesser Antilles, Earth Planets and Space, Vol. 52, 153-165, doi: 10.5047/eps.2009.07.003, 2010. Lesparre et al., Geophysical muon imaging: feasibility and limits, Geophysical Journal International, Vol. 183, 1348-1361, doi: 10.1111/j.1365-246X.2010.04790.x, 2010. Lesparre et al., Design and Operation of a Field Telescope for Cosmic Ray Geophysical Tomography, Nuclear Instruments and Methods in Physics Research A, to appear, 2011a. Lesparre et al., Bayesian Dual Inversion of Experimental Telescope Acceptance and Integrated Flux for Geophysical Muon Tomography, Geophysical Journal International, to appear, 2011b.

  9. Resolution capacity of geophysical monitoring regarding permafrost degradation induced by hydrological processes

    Science.gov (United States)

    Mewes, Benjamin; Hilbich, Christin; Delaloye, Reynald; Hauck, Christian

    2017-12-01

    Geophysical methods are often used to characterize and monitor the subsurface composition of permafrost. The resolution capacity of standard methods, i.e. electrical resistivity tomography and refraction seismic tomography, depends not only on static parameters such as measurement geometry, but also on the temporal variability in the contrast of the geophysical target variables (electrical resistivity and P-wave velocity). Our study analyses the resolution capacity of electrical resistivity tomography and refraction seismic tomography for typical processes in the context of permafrost degradation using synthetic and field data sets of mountain permafrost terrain. In addition, we tested the resolution capacity of a petrophysically based quantitative combination of both methods, the so-called 4-phase model, and through this analysed the expected changes in water and ice content upon permafrost thaw. The results from the synthetic data experiments suggest a higher sensitivity regarding an increase in water content compared to a decrease in ice content. A potentially larger uncertainty originates from the individual geophysical methods than from the combined evaluation with the 4-phase model. In the latter, a loss of ground ice can be detected quite reliably, whereas artefacts occur in the case of increased horizontal or vertical water flow. Analysis of field data from a well-investigated rock glacier in the Swiss Alps successfully visualized the seasonal ice loss in summer and the complex spatially variable ice, water and air content changes in an interannual comparison.

  10. Resolution capacity of geophysical monitoring regarding permafrost degradation induced by hydrological processes

    Directory of Open Access Journals (Sweden)

    B. Mewes

    2017-12-01

    Full Text Available Geophysical methods are often used to characterize and monitor the subsurface composition of permafrost. The resolution capacity of standard methods, i.e. electrical resistivity tomography and refraction seismic tomography, depends not only on static parameters such as measurement geometry, but also on the temporal variability in the contrast of the geophysical target variables (electrical resistivity and P-wave velocity. Our study analyses the resolution capacity of electrical resistivity tomography and refraction seismic tomography for typical processes in the context of permafrost degradation using synthetic and field data sets of mountain permafrost terrain. In addition, we tested the resolution capacity of a petrophysically based quantitative combination of both methods, the so-called 4-phase model, and through this analysed the expected changes in water and ice content upon permafrost thaw. The results from the synthetic data experiments suggest a higher sensitivity regarding an increase in water content compared to a decrease in ice content. A potentially larger uncertainty originates from the individual geophysical methods than from the combined evaluation with the 4-phase model. In the latter, a loss of ground ice can be detected quite reliably, whereas artefacts occur in the case of increased horizontal or vertical water flow. Analysis of field data from a well-investigated rock glacier in the Swiss Alps successfully visualized the seasonal ice loss in summer and the complex spatially variable ice, water and air content changes in an interannual comparison.

  11. 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…

  12. Reliability estimation system: its application to the nuclear geophysical sampling of ore deposits

    International Nuclear Information System (INIS)

    Khaykovich, I.M.; Savosin, S.I.

    1992-01-01

    The reliability estimation system accepted in the Soviet Union for sampling data in nuclear geophysics is based on unique requirements in metrology and methodology. It involves estimating characteristic errors in calibration, as well as errors in measurement and interpretation. This paper describes the methods of estimating the levels of systematic and random errors at each stage of the problem. The data of nuclear geophysics sampling are considered to be reliable if there are no statistically significant, systematic differences between ore intervals determined by this method and by geological control, or by other methods of sampling; the reliability of the latter having been verified. The difference between the random errors is statistically insignificant. The system allows one to obtain information on the parameters of ore intervals with a guaranteed random error and without systematic errors. (Author)

  13. Comparison Study to the Use of Geophysical Methods at Archaeological Sites Observed by Various Remote Sensing Techniques in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Roman Křivánek

    2017-09-01

    Full Text Available A combination of geophysical methods could be very a useful and a practical way of verifying the origin and precise localisation of archaeological situations identified by different remote sensing techniques. The results of different methods (and scales of monitoring these fully non-destructive methods provide distinct data and often complement each other. The presented examples of combinations of these methods/techniques in this study (aerial survey, LIDAR-ALS and surface magnetometer or resistivity survey could provide information on some specifics and may also be limitations in surveying different archaeological terrains, types of archaeological situations and activities. The archaeological site in this contribution is considered to be a material of this study. In case of Neolithic ditch enclosure near Kolín were compared aerial prospection data, magnetometer survey and aerial photo-documentation of excavated site. In the case of hillforts near Levousy we compared LIDAR data with aerial photography and large-scale magnetometer survey. In the case of the medieval castle Liběhrad we compared LIDAR data with geoelectric resistivity measurement. In case of a burial mound cemetery we combined LIDAR data with magnetometer survey. In the case of the production area near Rynartice we combined LIDAR data with magnetometer and resistivity measurements and result of archaeological excavation. Fortunately for successful combination of geophysical and remote sensing results, their conditions and factors for efficient use in archaeology are not the same. On the other hand, the quality and state of many prehistoric, early medieval, medieval and also modern archaeological sites is rapidly changing over time and both groups of techniques represent important support for their comprehensive and precise documentation and protection.

  14. To Measure Probable Physical Changes On The Earth During Total Solar Eclipse Using Geophysical Methods

    International Nuclear Information System (INIS)

    Gocmen, C.

    2007-01-01

    When the total solar eclipse came into question, people connected the eclipse with the earthquake dated 17.08.1999. We thought if any physical parameters change during total solar eclipse on the earth, we could measure this changing and we did the project 'To Measure Probable Physical Changes On The Earth During Total Solar Eclipse Using Geophysical Methods' We did gravity, magnetic and self-potential measurements at Konya and Ankara during total solar eclipse (29, March, 2006) and the day before eclipse and the day after eclipse. The measurements went on three days continuously twenty-four hours at Konya and daytime in Ankara. Bogazici University Kandilli Observatory gave us magnetic values in Istanbul and we compare the values with our magnetic values. Turkish State Meteorological Service sent us temperature and air pressure observations during three days, in Konya and Ankara. We interpreted all of them

  15. Looking Forward to the electronic Geophysical Year

    Science.gov (United States)

    Kamide, Y.; Baker, D. N.; Thompson, B.; Barton, C.; Kihn, E.

    2004-12-01

    During the International Geophysical Year (1957-1958), member countries established many new capabilities pursuing the major IGY objectives of collecting geophysical data as widely as possible and providing free access to these data for all scientists around the globe. A key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories. The worldwide scientific community has now endorsed and is promoting an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the 50th anniversary of the IGY in 2007-2008 and would provide a forward impetus to geophysics in the 21st century, similar to that provide by the IGY fifty years ago. The eGY concept advocates the establishment of a series of virtual geophysical observatories now being deployed in cyberspace. We discuss plans to aggregate measurements into a readily accessible database along with analysis, visualization, and display tools that will make information available and useful to the scientific community, to the user community, and to the general public. We are examining the possibilities for near-realtime acquisition of data and utilization of forecast tools in order to provide users with advanced space weather capabilities. This program will provide powerful tools for education and public outreach concerning the connected Sun-Earth System.

  16. Geophysical Investigations at Hidden Dam, Raymond, California: Summary of Fieldwork and Data Analysis

    Science.gov (United States)

    Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

    2010-01-01

    Geophysical field investigations have been carried out at the Hidden Dam in Raymond, California for the purpose of better understanding the hydrogeology and seepage-related conditions at the site. Known seepage areas on the northwest right abutment area of the downstream side of the dam are documented by Cedergren. Subsequent to the 1980 seepage study, a drainage blanket with a subdrain system was installed to mitigate downstream seepage. Flow net analysis provided by Cedergren suggests that the primary seepage mechanism involves flow through the dam foundation due to normal reservoir pool elevations, which results in upflow that intersects the ground surface in several areas on the downstream side of the dam. In addition to the reservoir pool elevations and downstream surface topography, flow is also controlled by the existing foundation geology as well as the presence or absence of a horizontal drain within the downstream portion of the dam. The purpose of the current geophysical work is to (1) identify present-day seepage areas that may not be evident due to the effectiveness of the drainage blanket in redirecting seepage water, and (2) provide information about subsurface geologic structures that may control subsurface flow and seepage. These tasks are accomplished through the use of two complementary electrical geophysical methods, self-potentials (SP) and direct-current (DC) electrical resistivity, which have been commonly utilized in dam-seepage studies. SP is a passive method that is primarily sensitive to active subsurface groundwater flow and seepage, whereas DC resistivity is an active-source method that is sensitive to changes in subsurface lithology and groundwater saturation. The focus of this field campaign was on the downstream area on the right abutment, or northwest side of the dam, as this is the main area of interest regarding seepage. Two exploratory self-potential lines were also collected on the downstream left abutment of the dam to identify

  17. 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

  18. Geophysical methods in protected environments. Electrical resistivity tomography; Métodos geofísicos en entornos naturales protegidos. Tomografía eléctrica

    Energy Technology Data Exchange (ETDEWEB)

    Rubio Sánchez-Aguililla, F.M.; Ramiro-Camacho, A.; Ibarra Torre, P.

    2017-09-01

    There is a strong interest in protecting the environment with the aim of its long term preservation. Sometimes the heritage value of these natural areas is related to their biodiversity as there are restricted ecosystems that depend directly on them. In other cases there a singular geological record might exist, essential for the understanding of certain processes affecting the planet, such as volcanic events or glacial periods. To achieve the protection and conservation of these areas it is necessary to generate knowledge about the distribution of geological materials and groundwater masses, to study the parameters that dominate the behaviour of these systems and then define those elements that require special protection or attention. In these protected environments, research methods with a minimal environmental impact should be used. Therefore, indirect methods, such as geophysical techniques, are reliable and complementary tools with a minimum environmental impact and are therefore useful for research these unique areas. The IGME has conducted several geophysical surveys in different protected environments in Spain with the aim of achieving a better understanding, and thus facilitate their preservation and exploitation in a sustainable manner. In this paper we present a review of some case studies where geophysical methods have been used. In all the cases electrical resistivity tomography has been the axis of the geophysical research and stands out due to its great effectiveness. The main objective of this communication is to divulgate and increase awareness of the important role that these geophysical methods can play in the sustainable study of these unique places. [Spanish] Existe un marcado interés en la protección de los entornos naturales, con el objetivo de su conservación a largo plazo. En ocasiones el valor patrimonial de estas áreas está asociado a su biodiversidad, debido a que existen ecosistemas restringidos que dependen directamente de ellas

  19. 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.

  20. Practices to enable the geophysical research spectrum: from fundamentals to applications

    Science.gov (United States)

    Kang, S.; Cockett, R.; Heagy, L. J.; Oldenburg, D.

    2016-12-01

    In a geophysical survey, a source injects energy into the earth and a response is measured. These physical systems are governed by partial differential equations and their numerical solutions are obtained by discretizing the earth. Geophysical simulations and inversions are tools for understanding physical responses and constructing models of the subsurface given a finite amount of data. SimPEG (http://simpeg.xyz) is our effort to synthesize geophysical forward and inverse methodologies into a consistent framework. The primary focus of our initial development has been on the electromagnetics (EM) package, with recent extensions to magnetotelluric, direct current (DC), and induced polarization. Across these methods, and applied geophysics in general, we require tools to explore and build an understanding of the physics (behaviour of fields, fluxes), and work with data to produce models through reproducible inversions. If we consider DC or EM experiments, with the aim of understanding responses from subsurface conductors, we require resources that provide multiple "entry points" into the geophysical problem. To understand the physical responses and measured data, we must simulate the physical system and visualize electric fields, currents, and charges. Performing an inversion requires that many moving pieces be brought together: simulation, physics, linear algebra, data processing, optimization, etc. Each component must be trusted, accessible to interrogation and manipulation, and readily combined in order to enable investigation into inversion methodologies. To support such research, we not only require "entry points" into the software, but also extensibility to new situations. In our development of SimPEG, we have sought to use leading practices in software development with the aim of supporting and promoting collaborations across a spectrum of geophysical research: from fundamentals to applications. Designing software to enable this spectrum puts unique

  1. An overview of geophysical technologies appropriate for characterization and monitoring at fractured-rock sites

    Science.gov (United States)

    Geophysical methods are used increasingly for characterization and monitoring at remediation sites in fractured-rock aquifers. The complex heterogeneity of fractured rock poses enormous challenges to groundwater remediation professionals, and new methods are needed to cost-effect...

  2. 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.

  3. 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...

  4. 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...

  5. New geophysical electromagnetic method of archeological object research in Egypt

    Science.gov (United States)

    Hachay, O. A.; Khachay, O. Yu.; Attia, Magdi.

    2009-04-01

    The demand to the enhanced geophysical technique and device, in addition to the precise interpretation of the geophysical data, is the resolution of the geophysical complex research, especially by the absence of priory information about the researched place. Therefore, an approach to use the planshet method of electromagnetic induction in the frequency geometry was developed by Hachay. et al., 1997a, 1997b, 1999, 2000, 2002, and 2005. The method was adapted to map and monitor the high complicated geological mediums, to determine the structural factors and criteria of the rock massif in the mine subsurface. The field observation and the way of interpretation make the new technology differ from other known earlier methods of field raying or tomography (Hachay et al., 1997c, 1999, and 2000).The 3D geoelectrical medium research is based on the concept of three staged interpreting of the alternating electromagnetic field in a frame of the block-layered isotropic medium with inclusion (Hachay 1997a, and 2002); in the first stage, the geoelectrical parameters of the horizontal block-layered medium, which includes the heterogeneities, are defined. In the second stage a geometrical model of the different local heterogeneities or groups inside the block-layered medium is constructed based on the local geoelectrical heterogeneities produced from the first stage after filtering the anomalous fields plunged in the medium. While in the third stage, the surfaces of the searched heterogeneities could be calculated in account of the physical parameters of the anomalous objects.For practical realization of that conception the system of observation for alternating electromagnetic field with use of vertical magnetic dipole was elaborated. Such local source of excitation and regular net of observations allows realizing overlapping by different angles of observation directions. As incoming data for interpretation, three components of modules of three components of magnetic field are

  6. Global status of and prospects for protection of terrestrial geophysical diversity.

    Science.gov (United States)

    Sanderson, Eric W; Segan, Daniel B; Watson, James E M

    2015-06-01

    Conservation of representative facets of geophysical diversity may help conserve biological diversity as the climate changes. We conducted a global classification of terrestrial geophysical diversity and analyzed how land protection varies across geophysical diversity types. Geophysical diversity was classified in terms of soil type, elevation, and biogeographic realm and then compared to the global distribution of protected areas in 2012. We found that 300 (45%) of 672 broad geophysical diversity types currently meet the Convention on Biological Diversity's Aichi Target 11 of 17% terrestrial areal protection, which suggested that efforts to implement geophysical diversity conservation have a substantive basis on which to build. However, current protected areas were heavily biased toward high elevation and low fertility soils. We assessed 3 scenarios of protected area expansion and found that protection focused on threatened species, if fully implemented, would also protect an additional 29% of geophysical diversity types, ecoregional-focused protection would protect an additional 24%, and a combined scenario would protect an additional 42%. Future efforts need to specifically target low-elevation sites with productive soils for protection and manage for connectivity among geophysical diversity types. These efforts may be hampered by the sheer number of geophysical diversity facets that the world contains, which makes clear target setting and prioritization an important next step. © 2015 Society for Conservation Biology.

  7. Geophysical techniques for exploration of concealed uranium deposits in the Gwalior basin

    International Nuclear Information System (INIS)

    Choudhary, Kalpan; Singh, R.B.

    2004-01-01

    There is no direct geophysical method for the exploration of concealed uranium ore. Scope of geophysics for this in the Gwalior basin comprises delineating the basement topography, demarcation or zones of intense fracturing intersecting the unconformities and to identify the presence of carbonaceous rocks, specially in the graben-like structures. These geophysical problems have been successfully solved in other places by employing IP, resistivity, SP and gravity techniques for basement mapping, identification of fracture zone/shear zone, delineation of electrical conductors like carbonaceous rocks and sulphides. Three such case histories are presented here that include: a). basement and shear/fracture zone mapping in the Vindhyan basin north of Son-Narmada lineament, b). delineation of conductive zone (proved to be carbon phyllite) in the Mahakoshal Group of Kanhara area of Sonbhadra district, UP and c). Identification of a conductive zone, proved to be sulphide body, within the Mahakoshal group in the Gurharpahar area of Sidhi and Sonbhadra districts of MP and UP respectively. In the context of exploration for concealed uranium in the Gwalior basin, it is suggested to employ IP, resistivity, SP, gravity and magnetic methods for delineation of conductive zones like carbonaceous rocks, basement topography, including the graben like structures, fracture zone, geological boundaries and demarcation of the basin boundary. (author)

  8. Geophysical imaging of near-surface structure using electromagnetic and seismic waves

    Science.gov (United States)

    Chen, Yongping

    percent. Keywords. geophysical imaging, hydrogeologic characterization, geometric moments, orthogonal moments, central mass, regularization, measurement errors, unsaturated zone, moisture content, water infiltration, VS2DT, GPR, EM forward model, simulated-annealing, shear wave velocity, microtremor, Rayleigh wave, Extended Spatial Autocorrelation (ESPAC) method.

  9. Geophysical monitoring in a hydrocarbon reservoir

    Science.gov (United States)

    Caffagni, Enrico; Bokelmann, Goetz

    2016-04-01

    Extraction of hydrocarbons from reservoirs demands ever-increasing technological effort, and there is need for geophysical monitoring to better understand phenomena occurring within the reservoir. Significant deformation processes happen when man-made stimulation is performed, in combination with effects deriving from the existing natural conditions such as stress regime in situ or pre-existing fracturing. Keeping track of such changes in the reservoir is important, on one hand for improving recovery of hydrocarbons, and on the other hand to assure a safe and proper mode of operation. Monitoring becomes particularly important when hydraulic-fracturing (HF) is used, especially in the form of the much-discussed "fracking". HF is a sophisticated technique that is widely applied in low-porosity geological formations to enhance the production of natural hydrocarbons. In principle, similar HF techniques have been applied in Europe for a long time in conventional reservoirs, and they will probably be intensified in the near future; this suggests an increasing demand in technological development, also for updating and adapting the existing monitoring techniques in applied geophysics. We review currently available geophysical techniques for reservoir monitoring, which appear in the different fields of analysis in reservoirs. First, the properties of the hydrocarbon reservoir are identified; here we consider geophysical monitoring exclusively. The second step is to define the quantities that can be monitored, associated to the properties. We then describe the geophysical monitoring techniques including the oldest ones, namely those in practical usage from 40-50 years ago, and the most recent developments in technology, within distinct groups, according to the application field of analysis in reservoir. This work is performed as part of the FracRisk consortium (www.fracrisk.eu); this project, funded by the Horizon2020 research programme, aims at helping minimize the

  10. Sixth national outdoor action conference on aquifer restoration, ground water monitoring and geophysical methods

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The 1992 Outdoor Action Conference was comprised of three days of technical presentations, workshops, demonstrations, and an exhibition. The sessions were devoted to the following topics: Vadose Zone Monitoring Technology; Ground Water Monitoring Technology; Ground Water Sampling Technology; Soil and Ground Water Remediation; and Surface and Borehole Geophysics. The meeting was sponsored by the National Ground Water Association. These papers were published exactly as submitted, without technical and grammatical editing or peer review

  11. Contribution of geophysical methods to the detection of underground cavities in salt series. Development in different projects in Morocco (roads, rail, etc…

    Directory of Open Access Journals (Sweden)

    Tlemçani M.K.

    2018-01-01

    Full Text Available As part of the geotechnical studies of a road project, a geophysical investigation by electrical tomography, microgravimetry, and boreholes, was carried out in order to locate if the areas can present or not a risks of ground instability along the road alignment. The road is located near a rock salt mine. This geophysical survey had demonstrated that the area may present major risks for the stability of the road platform. This risk is related to the existence of large expanses of saliferous rocks.The dissolution and exploitation of salt provoked underground voids under the future road. The results of this geophysical survey have allowed the designer office to propose more suitable solutions to solve this problem or even the possibility of shifting another site.

  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. Geophysical fluid dynamics understanding (almost) everything with rotating shallow water models

    CERN Document Server

    Zeitlin, Vladimir

    2018-01-01

    The book explains the key notions and fundamental processes in the dynamics of the fluid envelopes of the Earth (transposable to other planets), and methods of their analysis, from the unifying viewpoint of rotating shallow-water model (RSW). The model, in its one- or two-layer versions, plays a distinguished role in geophysical fluid dynamics, having been used for around a century for conceptual understanding of various phenomena, for elaboration of approaches and methods, to be applied later in more complete models, for development and testing of numerical codes and schemes of data assimilations, and many other purposes. Principles of modelling of large-scale atmospheric and oceanic flows, and corresponding approximations, are explained and it is shown how single- and multi-layer versions of RSW arise from the primitive equations by vertical averaging, and how further time-averaging produces celebrated quasi-geostrophic reductions of the model. Key concepts of geophysical fluid dynamics are exposed and inte...

  14. 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

  15. Moving Beyond IGY: An Electronic Geophysical Year (eGY) Concept

    Science.gov (United States)

    Baker, D. N.; Barton, C. E.; Rodger, A. S.; Thompson, B. J.; Fraser, B.; Papitashvili, V.

    2003-12-01

    During the International Geophysical Year (1957-1958), member countries established many new geophysical observatories pursuing the major IGY objectives - to collect geophysical data as widely as possible and to provide free access to these data for all scientists around the globe. Today, geophysics has attained a rather good understanding within traditional regions, i.e., the atmosphere, ionosphere, magnetosphere, and other such geospheres. At the same time, it has become clear that much of the new and important science is coming from the studies of interfaces and coupling between geospheres. Thus, if geophysical data are made `'transparently'' available to a much wider range of scientists and students than to those who do the observations, then new and exciting discoveries can be expected. An International Association of Geomagnetic and Aeronomy (IAGA) task force, recognizing that a key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories, proposes that for the 50th anniversary of IGY, the worldwide scientific community should endorse and promote an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the IGY in 2007-2008 and provide a forward impetus to geophysics in 21st century, similar to that provided by the IGY fifty years ago. The IAGA task force strongly advocates: (1) Securing permission and release of existing data; (2) Creating access to information; and (3) Conversion of relevant analog data to digital form. The eGY concept embraces all available and upcoming geophysical data (e.g., atmospheric, ionospheric, geomagnetic, gravity, etc.) through the establishment of a series of virtual geophysical observatories now being `'deployed'' in cyberspace. The eGY concept is modern, global, and timely; it is attractive, pragmatic, and affordable. The eGY is based on the existing and continually developing computing/networking technologies (e.g., XML, Semantic Web

  16. 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.

  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. Nuclear geophysical methods for exploration of wells in fields of solid mineral deposits

    International Nuclear Information System (INIS)

    Fel'dman, I.I.; Blyumentsev, A.M.; Karnikolo, V.F.; Zheltikov, A.N.

    1974-01-01

    Chromite and sulphur deposits have been used to illustrate the necessity and desirabilty of applying a combination of nuclear-geophysics logging methods and correlations between individual rock and ore components for localization and evaluation of ore bodies in borehole sections. On chromite deposits the combination includes neutron-capture spectrometric gamma-logging, epithermal neutron-neutron logging, selective gamma-gamma logging and gamma-gamma density logging. Neutron-capture spectrometric gamma-logging ensures an unambiguous localization of ores in borehole sections; epithermal neutron-neutron logging enables ores to be separated by the degree of dissemination; selective gamma-gamma logging is used to determine the content of Cr 2 O 3 and gamma-gamma density logging determines the volume weight. In addition a close correlation between Cr 2 O 3 and SiO 2 contents allows the silica content to be estimated. Application of a three-channel apparatus of the RSK-3 type ensures that all the measurements are made in two descent-ascension operations. The implementation of the combination described has ensured transition to drilling with a reduced selection of core samples. On sulphur deposits of carbonate type the combination includes epithermal neutron-neutron logging, gamma-gamma density logging and neutron-capture spectrometric gamma-logging

  19. Under the pile. Understanding subsurface dynamics of historical cities trough geophysical models interpretation

    Science.gov (United States)

    Bernardes, Paulo; Pereira, Bruno; Alves, Mafalda; Fontes, Luís; Sousa, Andreia; Martins, Manuela; Magalhães, Fernanda; Pimenta, Mário

    2017-04-01

    Braga is one of the oldest cities of the Iberian NW and as of so, the research team's studying the city's historical core for the past 40 years is often confronted with the unpredictability factor laying beneath an urban site with such a long construction history. In fact, Braga keeps redesigning its urban structure over itself on for the past 2000 years, leaving us with a research object filled with an impressive set of construction footprints from the various planning decisions that were taken in the city along its historical path. Aiming for a predicting understanding of the subsoil, we have used near surface geophysics as an effort of minimizing the areas of intervention for traditional archaeological survey techniques. The Seminário de Santiago integrated geophysical survey is an example of the difficulties of interpreting geophysical models in very complex subsurface scenarios. This geophysical survey was planned in order to aid the requalification project being designed for this set of historical buildings, that are estimated to date back to the 16h century, and that were built over one of the main urban arteries of both roman and medieval layers of Braga. We have used both GPR as well as ERT methods for the geophysical survey, but for the purpose of this article, we will focus in the use of the ERT alone. For the interpretation of the geophysical models we've cross-referenced the dense knowledge existing over the building's construction phases with the complex geophysical data collected, using mathematical processing and volume-based visualization techniques, resorting to the use of Res2Inv©, Paraview© and Voxler® software's. At the same time we tried to pinpoint the noise caused by the past 30 year's infrastructural interventions regarding the replacement of the building's water and sanitation systems and for which we had no design plants, regardless of its recent occurring. The deep impact of this replacement actions revealed by the archaeological

  20. 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.

  1. Automated recognition of stratigraphic marker shales from geophysical logs in iron ore deposits

    Science.gov (United States)

    Silversides, Katherine; Melkumyan, Arman; Wyman, Derek; Hatherly, Peter

    2015-04-01

    The mining of stratiform ore deposits requires a means of determining the location of stratigraphic boundaries. A variety of geophysical logs may provide the required data but, in the case of banded iron formation hosted iron ore deposits in the Hamersley Ranges of Western Australia, only one geophysical log type (natural gamma) is collected for this purpose. The information from these logs is currently processed by slow manual interpretation. In this paper we present an alternative method of automatically identifying recurring stratigraphic markers in natural gamma logs from multiple drill holes. Our approach is demonstrated using natural gamma geophysical logs that contain features corresponding to the presence of stratigraphically important marker shales. The host stratigraphic sequence is highly consistent throughout the Hamersley and the marker shales can therefore be used to identify the stratigraphic location of the banded iron formation (BIF) or BIF hosted ore. The marker shales are identified using Gaussian Processes (GP) trained by either manual or active learning methods and the results are compared to the existing geological interpretation. The manual method involves the user selecting the signatures for improving the library, whereas the active learning method uses the measure of uncertainty provided by the GP to select specific examples for the user to consider for addition. The results demonstrate that both GP methods can identify a feature, but the active learning approach has several benefits over the manual method. These benefits include greater accuracy in the identified signatures, faster library building, and an objective approach for selecting signatures that includes the full range of signatures across a deposit in the library. When using the active learning method, it was found that the current manual interpretation could be replaced in 78.4% of the holes with an accuracy of 95.7%.

  2. Application of electrical geophysics to the release of water resources, case of Ain Leuh (Morocco)

    Science.gov (United States)

    Zitouni, A.; Boukdir, A.; El Fjiji, H.; Baite, W.; Ekouele Mbaki, V. R.; Ben Said, H.; Echakraoui, Z.; Elissami, A.; El Maslouhi, M. R.

    2018-05-01

    Being seen needs in increasing waters in our contry for fine domestics, manufactures and agricultural, the prospecting of subterranean waters by geologic and hydrogeologic classic method remains inaplicable in the cases of the regions where one does not arrange drillings or polls (soundings) of gratitude (recongnition) in very sufficient (self-important) number. In that case of figure, the method of prospecting geophysics such as the method of nuclear magnetic resonance (NMR) and the method of the geophysics radar are usually used most usually because they showed, worldwide, results very desive in the projects of prospecting and evaluation of the resources in subterranean waters. In the present work, which concerns only the methodology of the electric resistivity, we treat the adopted methodological approach and the study of the case of application in the tray of Ajdir Ain Leuh.

  3. A portable marine geophysical data access and management system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Narvekar, P.

    Geophysical Oracle Database Management System (GPODMS) that is residing on UNIX True 64 Compaq Alpha server. GPODMS is a stable Oracle database system for longterm storage and systematic management of geophysical data and information of various disciplines...

  4. "Geo-statistics methods and neural networks in geophysical applications: A case study"

    Science.gov (United States)

    Rodriguez Sandoval, R.; Urrutia Fucugauchi, J.; Ramirez Cruz, L. C.

    2008-12-01

    The study is focus in the Ebano-Panuco basin of northeastern Mexico, which is being explored for hydrocarbon reservoirs. These reservoirs are in limestones and there is interest in determining porosity and permeability in the carbonate sequences. The porosity maps presented in this study are estimated from application of multiattribute and neural networks techniques, which combine geophysics logs and 3-D seismic data by means of statistical relationships. The multiattribute analysis is a process to predict a volume of any underground petrophysical measurement from well-log and seismic data. The data consist of a series of target logs from wells which tie a 3-D seismic volume. The target logs are neutron porosity logs. From the 3-D seismic volume a series of sample attributes is calculated. The objective of this study is to derive a set of attributes and the target log values. The selected set is determined by a process of forward stepwise regression. The analysis can be linear or nonlinear. In the linear mode the method consists of a series of weights derived by least-square minimization. In the nonlinear mode, a neural network is trained using the select attributes as inputs. In this case we used a probabilistic neural network PNN. The method is applied to a real data set from PEMEX. For better reservoir characterization the porosity distribution was estimated using both techniques. The case shown a continues improvement in the prediction of the porosity from the multiattribute to the neural network analysis. The improvement is in the training and the validation, which are important indicators of the reliability of the results. The neural network showed an improvement in resolution over the multiattribute analysis. The final maps provide more realistic results of the porosity distribution.

  5. Cost-effective geophysical survey systems for uranium exploration

    International Nuclear Information System (INIS)

    Hasbrouck, J.C.

    1981-01-01

    When planning a uranium exploration survey the question always arises as to how to take advantage of the different exploration methods and equipment for maximum probability of success. Discussed here are the choice of radiometric geophysical equipment, its effectiveness in identifying targets, its limitations, and the criteria for selection. Particular attention is given to systems that are suitable for the exploration programmes of small size and on a small budget, that are common in Latin America. (author)

  6. Characterising and modelling regolith stratigraphy using multiple geophysical techniques

    Science.gov (United States)

    Thomas, M.; Cremasco, D.; Fotheringham, T.; Hatch, M. A.; Triantifillis, J.; Wilford, J.

    2013-12-01

    Regolith is the weathered, typically mineral-rich layer from fresh bedrock to land surface. It encompasses soil (A, E and B horizons) that has undergone pedogenesis. Below is the weathered C horizon that retains at least some of the original rocky fabric and structure. At the base of this is the lower regolith boundary of continuous hard bedrock (the R horizon). Regolith may be absent, e.g. at rocky outcrops, or may be many 10's of metres deep. Comparatively little is known about regolith, and critical questions remain regarding composition and characteristics - especially deeper where the challenge of collecting reliable data increases with depth. In Australia research is underway to characterise and map regolith using consistent methods at scales ranging from local (e.g. hillslope) to continental scales. These efforts are driven by many research needs, including Critical Zone modelling and simulation. Pilot research in South Australia using digitally-based environmental correlation techniques modelled the depth to bedrock to 9 m for an upland area of 128 000 ha. One finding was the inability to reliably model local scale depth variations over horizontal distances of 2 - 3 m and vertical distances of 1 - 2 m. The need to better characterise variations in regolith to strengthen models at these fine scales was discussed. Addressing this need, we describe high intensity, ground-based multi-sensor geophysical profiling of three hillslope transects in different regolith-landscape settings to characterise fine resolution (i.e. a number of frequencies; multiple frequency, multiple coil electromagnetic induction; and high resolution resistivity. These were accompanied by georeferenced, closely spaced deep cores to 9 m - or to core refusal. The intact cores were sub-sampled to standard depths and analysed for regolith properties to compile core datasets consisting of: water content; texture; electrical conductivity; and weathered state. After preprocessing (filtering, geo

  7. 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

  8. Robust spatialization of soil water content at the scale of an agricultural field using geophysical and geostatistical methods

    Science.gov (United States)

    Henine, Hocine; Tournebize, Julien; Laurent, Gourdol; Christophe, Hissler; Cournede, Paul-Henry; Clement, Remi

    2017-04-01

    Research on the Critical Zone (CZ) is a prerequisite for undertaking issues related to ecosystemic services that human societies rely on (nutrient cycles, water supply and quality). However, while the upper part of CZ (vegetation, soil, surface water) is readily accessible, knowledge of the subsurface remains limited, due to the point-scale character of conventional direct observations. While the potential for geophysical methods to overcome this limitation is recognized, the translation of the geophysical information into physical properties or states of interest remains a challenge (e.g. the translation of soil electrical resistivity into soil water content). In this study, we propose a geostatistical framework using the Bayesian Maximum Entropy (BME) approach to assimilate geophysical and point-scale data. We especially focus on the prediction of the spatial distribution of soil water content using (1) TDR point-scale measurements of soil water content, which are considered as accurate data, and (2) soil water content data derived from electrical resistivity measurements, which are uncertain data but spatially dense. We used a synthetic dataset obtained with a vertical 2D domain to evaluate the performance of this geostatistical approach. Spatio-temporal simulations of soil water content were carried out using Hydrus-software for different scenarios: homogeneous or heterogeneous hydraulic conductivity distribution, and continuous or punctual infiltration pattern. From the simulations of soil water content, conceptual soil resistivity models were built using a forward modeling approach and point sampling of water content values, vertically ranged, were done. These two datasets are similar to field measurements of soil electrical resistivity (using electrical resistivity tomography, ERT) and soil water content (using TDR probes) obtained at the Boissy-le-Chatel site, in Orgeval catchment (East of Paris, France). We then integrated them into a specialization

  9. A state-space Bayesian framework for estimating biogeochemical transformations using time-lapse geophysical data

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; Hubbard, S.; Williams, K.; Pride, S.; Li, L.; Steefel, C.; Slater, L.

    2009-04-15

    We develop a state-space Bayesian framework to combine time-lapse geophysical data with other types of information for quantitative estimation of biogeochemical parameters during bioremediation. We consider characteristics of end-products of biogeochemical transformations as state vectors, which evolve under constraints of local environments through evolution equations, and consider time-lapse geophysical data as available observations, which could be linked to the state vectors through petrophysical models. We estimate the state vectors and their associated unknown parameters over time using Markov chain Monte Carlo sampling methods. To demonstrate the use of the state-space approach, we apply it to complex resistivity data collected during laboratory column biostimulation experiments that were poised to precipitate iron and zinc sulfides during sulfate reduction. We develop a petrophysical model based on sphere-shaped cells to link the sulfide precipitate properties to the time-lapse geophysical attributes and estimate volume fraction of the sulfide precipitates, fraction of the dispersed, sulfide-encrusted cells, mean radius of the aggregated clusters, and permeability over the course of the experiments. Results of the case study suggest that the developed state-space approach permits the use of geophysical datasets for providing quantitative estimates of end-product characteristics and hydrological feedbacks associated with biogeochemical transformations. Although tested here on laboratory column experiment datasets, the developed framework provides the foundation needed for quantitative field-scale estimation of biogeochemical parameters over space and time using direct, but often sparse wellbore data with indirect, but more spatially extensive geophysical datasets.

  10. Pollutants transport and distribution studies in groundwater system by nuclear, geophysics and hydrogeochemical methods

    International Nuclear Information System (INIS)

    Mohd Tadza Abdul Rahman; Daud Mohamad

    2000-01-01

    In Malaysia, the most common means of managing municipal refuse is by dumping it indiscriminately in piles on the selected open land. Leachate that is formed primarily in association with precipitation that infiltrates through the refuse normally results in the migration of leachate into underlying groundwater zone. The study of pollutant transport derived from domestic refuse and their impact on water quality in groundwater system has been performed in a selected landfill site at Gemencheh, Negeri Sembilan. The study involved the determination of flow velocity and flow direction of pollutants by nuclear techniques and a detail survey by geophysical method as well as hydrogeochemical approach as a supporting evidence of pollution occurrence. Hydrogeochemical approach involved the determination of pollutants species such as chloride and nitrate. A network of about 30 observation points had been identified and sampled. The results of the study have shown that the pollutants were concentrated at the middle of the dumping site and transported with the flow velocity between 0.2-15.4 metres per day toward northeast direction. Furthermore, the study established that the municipal or domestic landfalls are considered as one of the potential sources of groundwater pollution in Malaysia

  11. 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

  12. 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....... This case study is mainly to compare geophysical investigations (MEP/IP) with existing PACES data and information from geotechnical drillings....

  13. Testing how geophysics can reduce the uncertainty of groundwater model predictions

    DEFF Research Database (Denmark)

    Christensen, Nikolaj Kruse; Christensen, Steen; Ferre, Ty

    2014-01-01

    Geophysical data are increasingly used to construct groundwater models. Such data are collected at lower cost and much higher density than the traditionally used geological, hydraulic, and hydrological data. The geophysical data are often inverted independently and used together with geological......, respectively. There is also complete flexibility in the choice of relationships between hydraulic and geophysical properties. Noise can be added to the synthetic hydrologic and geophysical datasets and these exhaustive data sets can be down sampled to represent realistic data sets of varying measurement...... with and covered by layered glaciofluvial and glacial deposits. The hydrological data consist of 35 hydraulic head measurements and one river discharge measurement, while the geophysical data consist of 77 TEM soundings. The data are inverted sequentially and jointly. Through this example, we highlight the value...

  14. Conserving the stage: climate change and the geophysical underpinnings of species diversity.

    Directory of Open Access Journals (Sweden)

    Mark G Anderson

    Full Text Available Conservationists have proposed methods for adapting to climate change that assume species distributions are primarily explained by climate variables. The key idea is to use the understanding of species-climate relationships to map corridors and to identify regions of faunal stability or high species turnover. An alternative approach is to adopt an evolutionary timescale and ask ultimately what factors control total diversity, so that over the long run the major drivers of total species richness can be protected. Within a single climatic region, the temperate area encompassing all of the Northeastern U.S. and Maritime Canada, we hypothesized that geologic factors may take precedence over climate in explaining diversity patterns. If geophysical diversity does drive regional diversity, then conserving geophysical settings may offer an approach to conservation that protects diversity under both current and future climates. Here we tested how well geology predicts the species diversity of 14 US states and three Canadian provinces, using a comprehensive new spatial dataset. Results of linear regressions of species diversity on all possible combinations of 23 geophysical and climatic variables indicated that four geophysical factors; the number of geological classes, latitude, elevation range and the amount of calcareous bedrock, predicted species diversity with certainty (adj. R(2 = 0.94. To confirm the species-geology relationships we ran an independent test using 18,700 location points for 885 rare species and found that 40% of the species were restricted to a single geology. Moreover, each geology class supported 5-95 endemic species and chi-square tests confirmed that calcareous bedrock and extreme elevations had significantly more rare species than expected by chance (P<0.0001, strongly corroborating the regression model. Our results suggest that protecting geophysical settings will conserve the stage for current and future biodiversity and may

  15. Complex nuclear geophysical methods and apparatus to increase the efficiency of prospecting extracting and processing nonradioactive minerals as examplified by tin ores

    International Nuclear Information System (INIS)

    Baldin, S.A.; Voloshchuk, S.N.; Egiazarov, B.G.; Zernov, L.V.; Luchin, I.A.; Matveev, V.V.; Pukhal'skij, L.Ch.; Chesnokov, N.I.

    1979-01-01

    Described is the complex of nuclear geophysical methods and apparatus, with the help of which the problem of the industrial control at all stages of ore concentrating industry are being solved. γ resonance and X-ray radiometric methods and apparatus providing express and not less accurate determination of general tin and tin in the form of cassiterite are used in the complex. The devices developed on the base of semiconductor spectrometers and used both under industrial conditions and in production regimes are used for the first time in the practice of ore concentrating industry. The essential positive effect of the complex on technical economical indices of the industry is found out; it allows to use more effective methods of extracting and processing technology. The similar complexes may be developed for other kinds of nonradioactive minerals

  16. MLS/Aura Level 2 Diagnostics, Geophysical Parameter Grid V004

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2DGG is the EOS Aura Microwave Limb Sounder (MLS) product containing geophysical diagnostic quantities pertaining directly to the standard geophysical data...

  17. Combined geophysical methods for mapping infiltration pathways at the Aurora Water Aquifer recharge and recovery site

    Science.gov (United States)

    Jasper, Cameron A.

    Although aquifer recharge and recovery systems are a sustainable, decentralized, low cost, and low energy approach for the reclamation, treatment, and storage of post- treatment wastewater, they can suffer from poor infiltration rates and the development of a near-surface clogging layer within infiltration ponds. One such aquifer recharge and recovery system, the Aurora Water site in Colorado, U.S.A, functions at about 25% of its predicted capacity to recharge floodplain deposits by flooding infiltration ponds with post-treatment wastewater extracted from river bank aquifers along the South Platte River. The underwater self-potential method was developed to survey self-potential signals at the ground surface in a flooded infiltration pond for mapping infiltration pathways. A method for using heat as a groundwater tracer within the infiltration pond used an array of in situ high-resolution temperature sensing probes. Both relatively positive and negative underwater self-potential anomalies are consistent with observed recovery well pumping rates and specific discharge estimates from temperature data. Results from electrical resistivity tomography and electromagnetics surveys provide consistent electrical conductivity distributions associated with sediment textures. A lab method was developed for resistivity tests of near-surface sediment samples. Forward numerical modeling synthesizes the geophysical information to best match observed self- potential anomalies and provide permeability distributions, which is important for effective aquifer recharge and recovery system design, and optimization strategy development.

  18. Contribution of geophysical methods in the study of the floodplain structure (the Litavka River, the Czech Republic)

    Science.gov (United States)

    Kotková, Kristýna; Matys Grygar, Tomáš; Tůmová, Štěpánka; Elznicová, Jitka

    2017-04-01

    Mining and processing of polymetallic ores near the city of Příbram (the Czech Republic) have strongly impacted the fluvial system of the Litavka River. Beside of polymetallic mining during several hundred years with a peak between 1850 and 1950, the Litavka River was also influenced by uranium ore mining between 1948 and 1989. Severe contamination of the Litavka River system is known, but the alluvial architecture and specific distribution of contamination has not yet been satisfactorily described. However, such pieces of information are necessary for the predictions of the future behaviour of contaminants in the river system. We used geophysical methods for visualisation of subsurface layers of sediments and we have proved them very useful for the survey of the floodplain structure. It is especially advantageous when the surface topography of the floodplain does not reveal its internal structure, e.g. due to floodplain levelling by aggradation. Specifically, dipole electromagnetic profiling, also denoted electromagnetic induction sensing (DEMP) was used for quick detection of major heterogeneities in the floodplain structure. In addition, electrical resistivity tomography (ERT) was used for the exploration of lines across the heterogeneities shown by DEMP. This approach allows to choose the appropriate plan for the subsequent sampling in the floodplain to include all its structural (lithogenetic) units. Such rational strategy allows for reducing total amount of sampled sites without the risk of losing important information and production of false images. Both used geophysical tools and manual drill coring and the elemental analysis by handheld X-ray fluorescence spectrometry produced clear images of floodplain architecture and pollutant distribution. The internal structure of the Litavka River floodplain shows that lateral deposition and reworking of sediments played the main roles in the floodplain building. In the next centuries the lateral channel movement

  19. 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.

  20. Geomorphological Analyses Integrating Geophysical Methods for Hydrocarbon Exploration in the Majaguillar-Corralillo Sector, Cuba

    Directory of Open Access Journals (Sweden)

    María Victoria Pérez-Peña

    2016-10-01

    Full Text Available A more detailed geomorphological study compared to the previous ones was carried out in order to demarcate the potential areas for petroleum exploration. A diagram that integrates geological, geomorphological and geophysical results was prepared. Two structurally surveyed morphological areas (I and II are proposed to address exploration. Area I is recommended to be the one with a higher probability given the presence of rocks of the continental margin at depth, which are the most potential location of petroleum occurrence in Cuba.

  1. 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.

  2. Cyclic Investigation of Geophysical Studies in the Exploration and Discovery of Natural Resources in Our Country; Uelkemizdeki Dogal Kaynaklarin Aranmasi ve Bulunmasinda Jeofizik Calismalarin Doenemsel Incelenmesi

    Energy Technology Data Exchange (ETDEWEB)

    Gonulalan, A U [TPAO, Research Department, Ankara (Turkey)

    2007-07-01

    Although the methods of exploration geophysics were first utilized after the discovery of an oil field in 1921, they have also applied in the old centuries. Likewise, the half of the total production in the United States of America is covered by new oil fields discovered by utilizing geophysical methods. The industry's energy necessity increases the interest to oil. The investments in the field of geophysics by the companies which makes large amount of money in order to discover new oil fields, widespread use of computers, the developments of space technology and world-wide nuclear competition even though its great danger for human beings have great share in the development of geophysics. Our country has 18 different types mines which has more than 10 billion $ potential. Geophysical engineers have great Kowledge and labor in the discovery of 1,795 trillion wealth from borax to building stone, and 60 billion $ oil and gas. On the other hand, as 1,5 billion investment in the field of geophysics is only 0.08 % of total investments, the increase of investments will add more contribution.

  3. 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.

  4. Geophysical logging for mineral exploration and development

    International Nuclear Information System (INIS)

    Plouffe, R.D.

    1981-01-01

    It is possible to retrieve from small-diameter holes geophysical data for qualitative interpretation in exploration and quantitative interpretation in the development of orebodies. The primary objectives in the exploration stage are to identify where, within a hole, economic minerals are, and to help in lithological interpretations. Other aspects, which are more quantitative, are the interpretation of downhole logs for parameters which can be used in surface geophysical methods (i.e. density for gravity surveys, acoustic velocities for seismic surveys, and magnetic susceptibility for airborne and ground magnetic surveys). Recent advances in equipment design, portability and durability have made downhole logging in exploration more inexpensive and reliable. This new equipment is being used to generate very precise quantitative results. This is especially true on uranium development projects. The interpretation of gamma logs for eU 3 O 8 values has finally become precise enough that they have begun to replace chemical values in reserve calculations. Another part of development data is density and equilibrium information, which, with today's technology, is being derived from downhole probing. In the years to come, the trends for many metals are toward neutron activation techniques, or in-situ assaying, and the use of multiple logs for better lithological and physical rock property determinations. (auth)

  5. 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.

  6. Noninvasive characterization of the Trecate (Italy) crude-oil contaminated site: links between contamination and geophysical signals.

    Science.gov (United States)

    Cassiani, Giorgio; Binley, Andrew; Kemna, Andreas; Wehrer, Markus; Orozco, Adrian Flores; Deiana, Rita; Boaga, Jacopo; Rossi, Matteo; Dietrich, Peter; Werban, Ulrike; Zschornack, Ludwig; Godio, Alberto; JafarGandomi, Arash; Deidda, Gian Piero

    2014-01-01

    The characterization of contaminated sites can benefit from the supplementation of direct investigations with a set of less invasive and more extensive measurements. A combination of geophysical methods and direct push techniques for contaminated land characterization has been proposed within the EU FP7 project ModelPROBE and the affiliated project SoilCAM. In this paper, we present results of the investigations conducted at the Trecate field site (NW Italy), which was affected in 1994 by crude oil contamination. The less invasive investigations include ground-penetrating radar (GPR), electrical resistivity tomography (ERT), and electromagnetic induction (EMI) surveys, together with direct push sampling and soil electrical conductivity (EC) logs. Many of the geophysical measurements were conducted in time-lapse mode in order to separate static and dynamic signals, the latter being linked to strong seasonal changes in water table elevations. The main challenge was to extract significant geophysical signals linked to contamination from the mix of geological and hydrological signals present at the site. The most significant aspects of this characterization are: (a) the geometrical link between the distribution of contamination and the site's heterogeneity, with particular regard to the presence of less permeable layers, as evidenced by the extensive surface geophysical measurements; and (b) the link between contamination and specific geophysical signals, particularly evident from cross-hole measurements. The extensive work conducted at the Trecate site shows how a combination of direct (e.g., chemical) and indirect (e.g., geophysical) investigations can lead to a comprehensive and solid understanding of a contaminated site's mechanisms.

  7. Borehole geophysics in nuclear power plant siting

    International Nuclear Information System (INIS)

    Crosby, J.W.; Scott, J.D.

    1979-01-01

    Miniaturized borehole geophysical equipment designed for use in ground-water investigations can be adapted to investigations of nuclear power plant sites. This equipment has proved to be of value in preliminary and comprehensive studies of interior basins where thick sequences of Quaternary clastic sediment, occasionally with associated volcanic rocks, pose problems of stratigraphic correlation. The unconsolidated nature of the deposits generally requires that exploratory holes be cased, which ordinarily restricts the borehole geophysical studies to the radiation functions--natural gamma, gamma-gamma, neutron-gamma, and neutron-epithermal neutron logs. Although a single log response may be dominant in a given area, correlations derive from consideration of all log responses as a composite group. Because major correlations usually are based upon subtle differences in the physical properties of the penetrated sediment, high-resolution logging procedures are employed with some sacrifice of the quantitative perameters important to petroleum technology. All geophysical field data are recorded as hard copy and as digital information on punched paper tape

  8. Uranium occurence in nature: Geophysical prospecting, and its occurence in Syria

    International Nuclear Information System (INIS)

    Al-Haj Rasheed, Zaki

    1985-01-01

    A general idea about naturaly occured uranium minerals such as uranite, pechblende, carnotite, coffinit, and bronnerit is given. At the same time, different geophysical methods and detecting devices applied for uranium exploration have been demonstrated. Investigations and studies carried out in Syria point to a uranium content of 100 ppm in the exploited Syrian phosphorite. 1 fig., 1 tab

  9. Bayesian Markov chain Monte Carlo Inversion of Time-Lapse Geophysical Data To Characterize the Vadose Zone

    DEFF Research Database (Denmark)

    Scholer, Marie; Irving, James; Zibar, Majken Caroline Looms

    Geophysical methods have the potential to provide valuable information on hydrological properties in the unsaturated zone. In particular, time-lapse geophysical data, when coupled with a hydrological model and inverted stochastically, may allow for the effective estimation of subsurface hydraulic...... parameters and their corresponding uncertainties. In this study, we use a Bayesian Markov-chain-Monte-Carlo (MCMC) inversion approach to investigate how much information regarding vadose zone hydraulic properties can be retrieved from time-lapse crosshole GPR data collected at the Arrenaes field site...

  10. Multi-method, multi-scale geophysical observations in the Obsidian Pool Thermal Area, Yellowstone National Park

    Science.gov (United States)

    Holbrook, W. S.; Carr, B.; Pasquet, S.; Sims, K. W. W.; Dickey, K.

    2016-12-01

    Despite the prominence of Yellowstone as the world's most active hydrothermal province, relatively little is known about the plumbing systems that link deeper hydrothermal fluids to the charismatic hot springs, geysers and mud pots at the surface. We present the results of a multi-method, multi-scale geophysical investigation of the Obsidian Pool Thermal Area (OPTA) in Yellowstone National Park. OPTA hosts acid-sulfate hot springs and mud pots with relatively low pH. We present the results of seismic refraction, electrical resistivity, time-domain EM (TEM), soil conductivity meter (EMI), and GPR data acquired in July 2016. There is a strong contrast in physical properties in the upper 50 m of the subsurface between the low-lying hydrothermal area and surrounding hills: the hydrothermal area has much lower seismic velocities ( 1 km/s vs 3 km/s) and electrical resistivity ( 20 ohm-m vs 300 ohm-m). A prominent zone of very low resistivity (<10 ohm-m) exists at about 20 m depth beneath all hydrothermal features. Poisson's ratio, calculated from P-wave refraction tomography and surface wave inversions, shows low values beneath the "frying pan," where gas is emerging in small fumaroles, suggesting that Poisson's ratio is an effective "gas detector" in hydrothermal areas. Near-surface resistivity mapped from EMI shows a strong correlation with hydrothermal areas previously mapped by heat flow, with areas of high heat flow generally having low resistivity near the surface. Two exceptions are (1) the "frying pan," which shows a central area of high resistivity (corresponding to escaping gas) surrounding by a halo of low resistivity, and (2) a broad area of low resistivity connecting the hydrothermal centers to the lake, which may be clay deposits. TEM data penetrate up to 200 m in depth and suggest that a reservoir of hydrothermal fluids may underlie the entire area, including beneath the forested hills, at depths greater than 100 m, but that they rise toward the surface in

  11. 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

  12. The application of geophysical logging at in-situ leaching uranium mine in China

    International Nuclear Information System (INIS)

    Liu Zeyao; Xu Shusheng; Li Zhongqiu

    1999-01-01

    The status of work, instrument and method employed for geophysical logging in different stages at in-situ leaching uranium mine are discussed and the development of software, electrical current logging and gamma ray logging are presented based on the requirement of in-situ leaching of uranium. In addition, new function and method with regard to home instrument are proposed for future work

  13. 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

  14. Integrating non-colocated well and geophysical data to capture subsurface heterogeneity at an aquifer recharge and recovery site

    Science.gov (United States)

    Gottschalk, Ian P.; Hermans, Thomas; Knight, Rosemary; Caers, Jef; Cameron, David A.; Regnery, Julia; McCray, John E.

    2017-12-01

    Geophysical data have proven to be very useful for lithological characterization. However, quantitatively integrating the information gained from acquiring geophysical data generally requires colocated lithological and geophysical data for constructing a rock-physics relationship. In this contribution, the issue of integrating noncolocated geophysical and lithological data is addressed, and the results are applied to simulate groundwater flow in a heterogeneous aquifer in the Prairie Waters Project North Campus aquifer recharge site, Colorado. Two methods of constructing a rock-physics transform between electrical resistivity tomography (ERT) data and lithology measurements are assessed. In the first approach, a maximum likelihood estimation (MLE) is used to fit a bimodal lognormal distribution to horizontal crosssections of the ERT resistivity histogram. In the second approach, a spatial bootstrap is applied to approximate the rock-physics relationship. The rock-physics transforms provide soft data for multiple point statistics (MPS) simulations. Subsurface models are used to run groundwater flow and tracer test simulations. Each model's uncalibrated, predicted breakthrough time is evaluated based on its agreement with measured subsurface travel time values from infiltration basins to selected groundwater recovery wells. We find that incorporating geophysical information into uncalibrated flow models reduces the difference with observed values, as compared to flow models without geophysical information incorporated. The integration of geophysical data also narrows the variance of predicted tracer breakthrough times substantially. Accuracy is highest and variance is lowest in breakthrough predictions generated by the MLE-based rock-physics transform. Calibrating the ensemble of geophysically constrained models would help produce a suite of realistic flow models for predictive purposes at the site. We find that the success of breakthrough predictions is highly

  15. 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.

  16. Palaeomagnetism principles and applications in geology, geophysics and archaeology

    CERN Document Server

    Tarling, D H

    1983-01-01

    Palaeomagnetism and archaeomagnetism are fascinating specialized studies because they are applicable to such a wide range of problems in geology, archaeology and geophysics. They can also be undertaken cheaply, when compared with most other geophysical techniques, and, at first sight, simply. In fact, real comprehension of the magnetic processes that have occurred in rocks and other types of material over several thousands or many millions of years is still extremely difficult to assess and measure. On this basis, this book cannot explain all such features, nor can it attempt to cover all the actual and potential applications of the method. All that can be attempted is to give an impression of the ways in which such techniques can be used in a wide variety of fields, and how these techniques are usually applied. The magnetization of rocks is, in fact, one of the earliest of the true sciences, but we are still not in a position to answer many of the problems posed. Consequently some of the examples given of ap...

  17. Patent Documents as a Resource for Studies and Education in Geophysics - An Approach.

    Science.gov (United States)

    Wollny, K. G.

    2016-12-01

    Patents are a highly neglected source of information in geophysics, although they supply a wealth of technical and historically relevant data and might be an important asset for researchers and students. The technical drawings and descriptions in patent documents provide insight into the personal work of a researcher or a scientific group and give detailed technical background information, show interdisciplinary solutions for similar problems, help to learn about inventions too advanced for their time but maybe useful now, and to explore the historical background and timelines of inventions and their inventors. It will be shown how to get access to patent documents and how to use them for research and education purposes. Exemplary inventions by well-known geoscientists or scientists in related fields will be presented to illustrate the usefulness of patent documents. The data pool used is the International Patent Classification (IPC) class G01V that the United Nations' World Intellectual Property Organisation (WIPO) has set up mainly for inventions with key aspects in geophysics. This class contains approximately 235,000 patent documents (July 2016) for methods, apparatuses or scientific instruments developed during scientific projects or by geophysical companies. The patent documents can be accessed via patent databases. The most important patent databases are for free, search functionality is self-explanatory and the amount of information to be extracted is enormous. For example, more than 90 million multilingual patent documents are currently available online (July 2016) in DEPATIS database of the German Patent and Trade Mark Office or ESPACENET of the European Patent Office. To summarize, patent documents are a highly useful tool for educational and research purposes to strengthen students' and scientists' knowledge in a practically orientated geophysical field and to widen the horizon to adjacent technical areas. Last but not least, they also provide insight

  18. Increasing the success rate of groundwater exploration in developing nation using geophysical methods: Case of a small community in Nigeria.

    Science.gov (United States)

    Isiorho, S. A.; Omole, D.; Aizebeokhai, A.

    2016-12-01

    About 35 percent of Nigeria's population of the more than 180 M relies on groundwater. Due to the lack of an adequate water supply system within Ogun State, many homes result to drilling their own private wells. Most groundwater is sourced from shallow wells (less than 30 m) and is often of poor water quality. The number of borehole failures is also alarming. Several entrepreneurs have seized on the lack of adequate water supply to drill for groundwater. Several of these wells have either failed or are not adequate for the purposed use of the water. There also appears to be no proper coordination of the citing of these wells. To increase the success rates of the boreholes, the use of geophysical methods amongst others is recommended. This study examines the exploration for groundwater and water quality in Ogun State in Nigeria, using Ota as an example. Ogun State has both significant surface and groundwater resources. However, due to the indiscriminate and lack of proper waste disposal, the vast majority of the surface waters and shallow well waters are impaired making them unsuitable for many users. To access a deeper groundwater source, a geophysical survey was performed to assist in finding a possible location for a borehole. A geophysical survey using the vertical electric sounding (VES) with Schlumberger configuration was carried out. The data shows that there are five layers within the proposed borehole site. Based on the data, it was suggested that a well be placed at a depth between 65-75 m (213-246 ft.). The borehole was drilled to 67m. This depth, from the literature, corresponds to the Abeokuta formation. A pump was installed at 66 m (217 ft.) depth and the first 50 feet of the borehole was grouted to prevent surface water from getting into the hole. A pumping test was performed for about two hours. While this was noteworthy, the data is not made available to any centralized body. No water chemistry was undertaken and more still needs to be done with

  19. Results of geophysical survey on Hanaore-fault in the Kyoto urban area; Butsuri tansa ni yoru Kyoto shigaichi ni okeru Hanaore danso chosa

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, T. [Geological Survey of Japan, Tsukuba (Japan); Echigo, T. [Osaka Soil Test, Osaka (Japan); Toshioka, T.; Matsubara, Y. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    This paper reports results of gravity survey and seismic survey using the shallow bed reflection method to identify distribution of the Hanaore fault in the Kyoto urban area. In the gravity survey, level differential structure caused by the fault was identified as an abrupt change in Bouger anomalous values. The continuity therefrom made the estimation possible on existence and positions of such faults as the Hanaore fault belonging to the Hanaore fault system, the Shishigaya fault, the Kaguraoka fault, and the Okazaki fault. The estimation as a result of the gravity survey include the following findings: the Hanaore fault runs from south of the Yoshidayama in the south-north direction; the distribution of the Okazaki fault has a level differential structure falling on the east side; the structure shows low Bouger anomaly distribution; and this area forms a rift valley belt. In the seismic survey using the shallow bed reflection method, no distinct reflection plane considered as the basement was verified because of influence from urban area noise. However, it was possible to estimate such an underground structure as a monoclinal fold from shapes of the reflection plane and the distribution depths. 7 refs., 5 figs.

  20. 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

    Among many research fields in volcanology, prediction of eruptions is the most important from the hazard- mitigation point of view. Most geophysicists have sought for the best physical parameters for this objective: various kinds of wave signals and geodesic data are two of such parameters. Being able to be remotely monitored gives them advantage over many other practical methods for volcano monitoring. On the other hand, increasing volcanic activity is always accompanied by mass transfer. The most swiftly-moving materials are volcanic gases which are the target geochemists have intensively studied although monitoring gases is rather tedious and limited for active volcanoes hosting crater lakes. A Japanese group lead by Bokuichiro Takano has recently developed an indirect method for monitoring gas injection into volcanic crater lakes. Polythionates are formed when SO2 and H2S are injected into the lake from subaqueous fumaroles. Such polythionates consist of chains of 4 to 6 sulphur atoms, the terminal ones of which are bonded with three oxygen atoms. The general formula for these anions is SxO62- (x= 4 to 6). Important to note is that SO2 input into the lake also depends upon the plumbing system of the volcanoes: conduits, cracks and hydrothermal reservoirs beneath the lake that usually differ from volcano to volcano. Despite such site-specific characters some general statements can be made on the behaviour of these chemical species. For example, at low volcanic activity S6O62- predominates while S4O62- and S5O62- become predominant with increasing SO2 that increases with volcanic activity. At higher SO2 input and high temperature polythionates disappear in the lake through interaction with aqueous SO2 (sulfitolysis). Thus, the ratios of the three polythionates or their absence serve as an indicator for various stages of volcanic activity. Monitoring polythionates is an independent method that can be compared with results from geophysical methods. However, it

  1. Geophysical mapping of complex glaciogenic large-scale structures

    DEFF Research Database (Denmark)

    Høyer, Anne-Sophie

    2013-01-01

    This thesis presents the main results of a four year PhD study concerning the use of geophysical data in geological mapping. The study is related to the Geocenter project, “KOMPLEKS”, which focuses on the mapping of complex, large-scale geological structures. The study area is approximately 100 km2...... data types and co-interpret them in order to improve our geological understanding. However, in order to perform this successfully, methodological considerations are necessary. For instance, a structure indicated by a reflection in the seismic data is not always apparent in the resistivity data...... information) can be collected. The geophysical data are used together with geological analyses from boreholes and pits to interpret the geological history of the hill-island. The geophysical data reveal that the glaciotectonic structures truncate at the surface. The directions of the structures were mapped...

  2. Geophysics report of Santa Rosa place Canelones province

    International Nuclear Information System (INIS)

    Cicalese, H.

    1984-01-01

    The Hydrogeology Section required to Geophysics Department of the DINAMIGE to carry out this report for Education and Culture Ministery, to study the feasibility of the exploration and exploitation of underground waters located in three properties zones in Santa Rosa's town, Canelones province. By means of the geoeletric methods it was possible to estimate the alluviums thickness ,sedimentary deposits or alteration mantels. The purpose of the present work has been to establish geologic and structural features through vertical electric well by means of which is been able to study the vertical variations of the resistivity .

  3. Reconsidering Volcanic Ocean Island Hydrology: Recent Geophysical and Drilling Results

    Science.gov (United States)

    Thomas, D. M.; Pierce, H. A.; Lautze, N. C.

    2017-12-01

    Recent results of geophysical surveys and exploratory drilling in Hawaii have suggested that Hawaii's hydrogeology may be more complex than has been generally recognized. Instead of a more-or-less homogeneous pile of highly permeable eruptive basalts that are intermittently punctuated by volcanic dikes confined to calderas and rift zones, we are finding that dike compartmentalization is occurring outside of recognized rift zones, leading to significantly higher volumes of stored groundwater within the island. Analysis of recent geophysical surveys have shown local water table elevations that are substantially higher than can be accounted for by the high hydraulic conductivities of Hawaiian basalts. Recent diamond wireline drilling results have also shown that sub-horizontal variations in permeability, associated with significant changes in eruptive character (e.g. explosive vs effusive activity) are acting as significant perching and confining bodies over significant aerial extents and suggest that these features also contribute to increased storage of recharge. Not only is storage much higher than previously assumed, these features appear to impact subsurface groundwater flow in ways that are not accounted for in traditional methods of computing sustainable yields for near shore aquifers: where buried confining formations extend to depths well below sea level, higher elevation recharge is being intercepted and diverted to deep submarine groundwater discharge well below depths that are typically investigated or quantified. We will provide a summary of the recent geophysical survey results along with a revised conceptual model for groundwater circulation within volcanic ocean islands.

  4. 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)

  5. Geophysical exploration of historical mine dumps for the estimation of valuable residuals

    Science.gov (United States)

    Martin, Tina; Knieß, Rudolf; Noell, Ursula; Hupfer, Sarah; Kuhn, Kerstin; Günther, Thomas

    2015-04-01

    Within the project ROBEHA, funded by the German Federal Ministry of Education and Research (033R105) the economic potential of different abandoned dump sites for mine waste in the Harz Mountains was investigated. Two different mining dumps were geophysically and mineralogically analysed in order to characterize the mine dump structure and to estimate the volume of the potential recycling material. The geophysical methods comprised geoelectrics, radar, and spectral induced polarization (SIP). One about 100-year old mining dump containing residues from density separated Ag- and Sb-rich Pb (Zn)-gangue ores was investigated in detail. Like most small-scale mining waste disposal sites this investigated dump is very heterogeneously structured. Therefore, 27 geoelectrical profiles, more than 50 radar profiles, and several SIP profiles were measured and analysed. The results from the radar measurements, registered with the GSSI system and a shielded 200 MHz antenna, show the near surface boundary layer (down to 3-4 m beneath surface) of the waste residuals. These results can be used as pre-information for the inversion process of the geoelectrical data. The geoelectrical results reveal the mineral residues as layers with higher resistivities (> 300 Ohm*m) than the surrounding material. The SIP method found low phase signals (mine dump and other parameters we get a first estimate for the volume of the residues but the economical viability and the environmental impact of the reworking of the dump still needs to be evaluated in detail. The results of the second mine dump, an abandoned Cu and Zn-rich slag heap, show that the slag residues are characterized by higher resistivities and higher phases. A localization of the slag residues which are covered by organic material could be realized applying these geophysical methods.

  6. The concept of geothermal exploration in west Java based on geophysical data

    Science.gov (United States)

    Gaffar, Eddy Z.

    2018-02-01

    Indonesia has the largest geothermal prospects in the world and most of them are concentrated in Java and Sumatera. The ones on Sumatra island are generally controlled by Sumatra Fault, either the main fault or the second and the third order fault. Geothermal in Java is still influenced by the subduction of oceanic plates from the south of Java island that forms the southern mountains extending from West Java to East Java. From a geophysical point of view, there is still no clue or concept that accelerates the process of geothermal exploration. The concept is that geothermal is located around the volcano (referred to the volcano as a host) and around the fault (fault as a host). There is another method from remote sensing analysis that often shows circular feature. In a study conducted by LIPI, we proposed a new concept for geothermal exploration which is from gravity analysis using Bouguer anomaly data from Java Island, which also show circular feature. The feature is supposed to be an "ancient crater" or a hidden caldera. Therefore, with this hypothesis, LIPI Geophysics team will try to prove whether this symptom can help accelerate the process of geothermal exploration on the island of West Java. Geophysical methods might simplify the exploration of geothermal prospect in West Java. Around the small circular feature, there are some large geothermal prospect areas such as Guntur, Kamojang, Drajat, Papandayan, Karaha Bodas, Patuha. The concept proposed by our team will try be applied to explore geothermal in Java Island for future work.

  7. 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.

  8. Evidence for a critical Earth: the New Geophysics

    Science.gov (United States)

    Crampin, Stuart; Gao, Yuan

    2015-04-01

    Phenomena that are critical-systems verging on criticality with 'butterfly wings' sensitivity are common - the weather, climate change; stellar radiation; the New York Stock Exchange; population explosions; population collapses; the life cycle of fruit-flies; and many more. It must be expected that the Earth, an archetypal complex heterogeneous interactive phenomena, is a critical-system, hence there is a New Geophysics imposing fundamentally new properties on conventional sub-critical geophysics. We shall show that, despite shear waves and shear-wave splitting (SWS) being observationally neglected, azimuthally-varying stress-aligned SWS is nearly universally observed throughout the Earth's crust and uppermost ~400km of the mantle. Caused by stress-aligned fluid-saturated microcracks (intergranular films of hydrolysed melt in the mantle), the microcracks are so closely-spaced that they verge on failure in fracturing and earthquakes. Phenomena that verge on failure in this way are critical-systems which impose a range of fundamental-new properties on conventional sub-critical geophysics including: self-similarity; monitorability; calculability; predictability; controllability; universality; and butterfly wings' sensitivity. We shall show how these phenomena have been consistently observed along millions of source-to-receiver ray paths confirming the New Geophysics. New Geophysics helps to explain many otherwise inexplicable observations including a number of geophysical conundrums such as the Gutenberg-Richter relationship which is used to describe the behaviour of conventional classic geophysics despite being massively non-linear. The great advantage of the critical Earth is that, unlike other critical-systems, the progress towards criticality can be monitored at almost any point within the deep interior of the material, by analysing observations of seismic SWS. This gives an unrivalled understanding of the detailed behaviour of a particular critical-system. This

  9. Geophysical surveys for buried waste detection at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Sandness, G.A.; Rising, J.L.; Kimbrough, J.R.

    1979-12-01

    This report describes a series of geophysical surveys performed at the Idaho National Engineering Laboratory (INEL). The main purpose of the surveys was to evaluate techniques, principally ground-penetrating radar, for detecting and mapping radioactive wastes buried in shallow trenches and pits. A second purpose was to determine the feasibility of using ground-penetrating radar to measure the depth of basalt bedrock. A prototype geophyscal survey system developed by the US Department of Energy's Pacific Northwest Laboratory was used for this study. Radar, magnetometer, and metal detector measurements were made at three sites in the Radioactive Waste Management Complex (RWMC) at INEL. Radar measurements were made at fourth site adjacent to the RWMC. The combination of three geophysical methods was shown to provide considerable information about the distribution of buried waste materials. The tests confirmed the potential effectiveness of the radar method, but they also pointed out the need for continued research and development in ground-penetrating radar technology. The radar system tested in this study appears to be capable of measuring the depth to basalt in the vicinity of the RWMC

  10. Monitoring Global Geophysical Fluids by Space Geodesy

    Science.gov (United States)

    Chao, Benjamin F.; Dehant, V.; Gross, R. S.; Ray, R. D.; Salstein, D. A.; Watkins, M.

    1999-01-01

    Since its establishment on 1/1/1998 by the International Earth Rotation Service, the Coordinating Center for Monitoring Global Geophysical Fluids (MGGF) and its seven Special Bureaus have engaged in an effort to support and facilitate the understanding of the geophysical fluids in global geodynamics research. Mass transports in the atmosphere-hydrosphere-solid Earth-core system (the "global geophysical fluids") will cause the following geodynamic effects on a broad time scale: (1) variations in the solid Earth's rotation (in length-of-day and polar motion/nutation) via the conservation of angular momentum and effected by torques at the fluid-solid Earth interface; (2) changes in the global gravitational field according to Newton's gravitational law; and (3) motion in the center of mass of the solid Earth relative to that of the whole Earth ("geocenter") via the conservation of linear momentum. These minute signals have become observable by space geodetic techniques, primarily VLBI, SLR, GPS, and DORIS, with ever increasing precision/accuracy and temporal/spatial resolution. Each of the seven Special Bureaus within MGGF is responsible for calculations related to a specific Earth component or aspect -- Atmosphere, Ocean, Hydrology, Ocean Tides, Mantle, Core, and Gravity/Geocenter. Angular momenta and torques, gravitational coefficients, and geocenter shift will be computed for geophysical fluids based on global observational data, and from state-of-the-art models, some of which assimilate such data. The computed quantities, algorithm and data formats are standardized. The results are archived and made available to the scientific research community. This paper reports the status of the MGGF activities and current results.

  11. Environmental Geophysical Study of the Groundwater Mineralization in a Plot of the Cotonou Littoral Zone (South Benin

    Directory of Open Access Journals (Sweden)

    Yalo Nicaise

    2012-01-01

    Full Text Available Geophysical investigations comprising electrical resistivity and electromagnetic conductivities methods were deployed in a 350 m2 sector, strewn with 11 wells. Within the framework of an environmental study on a small scale in the south of Benin, the water conductivity of these wells was measured to determine in a direct way mineralization of the coastal water table in the littoral zone. This environmental study aimed to prospect by the geophysical methods the space extension of the water table mineralization obtained by direct measurements of water conductivity in the well and the depth of the fresh water/salted water interface in the coastal aquifer. Electromagnetic measurements of conductivities made it possible to chart a gradient of mineralization in the northwest direction. The logs of vertical electric soundings showed a deepening of the fresh water/salted water interface in the southern part and its rupture in the northern part. The electrical resistivities of the interface are sensitive to the degree of its mineralization. It has been observed that the geophysical methods in electrical and electromagnetic prospection are a great contribution to the environmental study of the water table mineralization in the littoral zone for a sustainable management of the water resource.

  12. DVS-SOFTWARE: An Effective Tool for Applying Highly Parallelized Hardware To Computational Geophysics

    Science.gov (United States)

    Herrera, I.; Herrera, G. S.

    2015-12-01

    Most geophysical systems are macroscopic physical systems. The behavior prediction of such systems is carried out by means of computational models whose basic models are partial differential equations (PDEs) [1]. Due to the enormous size of the discretized version of such PDEs it is necessary to apply highly parallelized super-computers. For them, at present, the most efficient software is based on non-overlapping domain decomposition methods (DDM). However, a limiting feature of the present state-of-the-art techniques is due to the kind of discretizations used in them. Recently, I. Herrera and co-workers using 'non-overlapping discretizations' have produced the DVS-Software which overcomes this limitation [2]. The DVS-software can be applied to a great variety of geophysical problems and achieves very high parallel efficiencies (90%, or so [3]). It is therefore very suitable for effectively applying the most advanced parallel supercomputers available at present. In a parallel talk, in this AGU Fall Meeting, Graciela Herrera Z. will present how this software is being applied to advance MOD-FLOW. Key Words: Parallel Software for Geophysics, High Performance Computing, HPC, Parallel Computing, Domain Decomposition Methods (DDM)REFERENCES [1]. Herrera Ismael and George F. Pinder, Mathematical Modelling in Science and Engineering: An axiomatic approach", John Wiley, 243p., 2012. [2]. Herrera, I., de la Cruz L.M. and Rosas-Medina A. "Non Overlapping Discretization Methods for Partial, Differential Equations". NUMER METH PART D E, 30: 1427-1454, 2014, DOI 10.1002/num 21852. (Open source) [3]. Herrera, I., & Contreras Iván "An Innovative Tool for Effectively Applying Highly Parallelized Software To Problems of Elasticity". Geofísica Internacional, 2015 (In press)

  13. The role of geophysical ERT method to evaluate the leakproofness of diapragm wall of deep foundation trenches on the example of the construction of retail and office complex in Lublin, Poland

    Directory of Open Access Journals (Sweden)

    Pacanowski Grzegorz

    2014-12-01

    Full Text Available This paper addresses the problem of assessing the leakproofness of the bottom of a deep foundation trench, secured by cavity wall, using geophysical methods of electrical resistivity tomography. The study was conducted on a large construction project in Lublin, in a place where there are complicated soil-water conditions: the groundwater level is above the proposed depth of foundation trench, the subsoil is heterogeneous, and there are karsted and weathered carbonate sediments with confined aquifer below the bottom of the trench. A hydraulic fracture occurred at the bottom of the trench during the engineering works, which caused the water flow into the trench. In order to recognize the soil-water conditions the first stage of geophysical measurements of electrical resistivity tomography (ERT was made. The applied methodology allowed to determine the extent of the hydraulic fracture zone within the bottom of foundation trench. In order to assess the leakproofness of Diaphragm Wall the geophysical ERT measurements were repeated (stage 2 A clear reduction in the value of the electrical resistivity of soils in the area of hydraulic fracture was caused by clay injection. The results of ERT measurements are discussed and graphically presented.

  14. Improved geophysical excitation of length-of-day constrained by Earth orientation parameters and satellite gravimetry products

    Science.gov (United States)

    Yu, Nan; Li, Jiancheng; Ray, Jim; Chen, Wei

    2018-05-01

    At time scales shorter than about two years, non-tidal LOD variations are mainly excited by angular momentum exchanges between the atmospheric, oceanic, and continental hydrological fluid envelopes and the underlying solid Earth. But, neither agreement among different geophysical models for the fluid dynamics nor consistency with geodetic observations of LOD has reached satisfactory levels. This is mainly ascribed to significant discrepancies and uncertainties in the theories and assumptions adopted by different modeling groups, in their numerical methods, and in the accuracy and coverage of global input data fields. Based on careful comparisons with more accurate geodetic measurements and satellite gravimetry products (from satellite laser ranging, SLR), observed length-of day (LOD) and C20 geopotential time series can provide strong constraints to evaluate or form combined geophysical models. In this study, wavelet decomposition is used to extract several narrow-band components to compare in addition to considering the total signals. We then make refinements to the least difference combination (LDC) method proposed by Chen et al. (2013b) to form multi-model geophysical excitations. Two combination variants, called the weighted mean combination (WMC2 and WMC4), are also evaluated. All the multi-model methods attempt to extract the best-modeled frequency components from each geophysical model by relying on geodetic excitation and the C20 series as references. The comparative performances of the three combinations LDC, WMC2 and WMC4 and the original single models are determined. We find that (1) the Estimating the Circulation and Climate of the Ocean (ECCO) and Max-Planck-Institute for Meteorology Ocean Model (MPIOM) give a more reliable view of the ocean redistributions than the Ocean Model for Circulation and Tides (OMCT) used by European Centre for Medium-Range Weather Forecasts (ECMWF), especially for the annual component; (2) C20 series from SLR can provide a

  15. Evaluation of the potential of the Clare Basin, SW Ireland, for onshore carbon sequestration using electromagnetic geophysical methods

    Science.gov (United States)

    Llovet, Joan Campanya i.; Ogaya, Xenia; Jones, Alan G.; Rath, Volker; Ledo, Juanjo; McConnell, Brian

    2015-04-01

    Carbon capture, sequestration and long-term storage (CCS) is a critically important and intellectually and technologically challenging bridging technology for assisting humanity to migrate from its dependence on fossil fuels to green energy over the next half century. The IRECCSEM project (www.ireccsem.ie) is a Science Foundation Ireland Investigator Project to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic geophysical data with existing geophysical and geological data. The main goals of the project are to determine porosity and permeability values of the potential reservoir formation as well as to evaluate the integrity of the seal formation. During the summer of 2014, a magnetotelluric (MT) survey was carried out in the Carboniferous Clare Basin (SW Ireland). Data from a total of 140 sites were acquired, including audio-magnetotelluric (AMT), broadband magnetotelluric (BBMT) and long period magnetotelluric (LMT) data. These new data added to existing MT data acquired at 32 sites during a feasibility pilot survey conducted in 2010. The nominal space between the 2014 sites was 0.6 km between AMT sites, 1.2 km between BBMT sites and 8 km between LMT sites. The electrical resistivity distribution beneath the survey area was constrained using three different types of electromagnetic data: MT impedance tensor responses (Z), geomagnetic transfer functions (GTF) and inter-station horizontal magnetic transfer-functions (HMT). A newly-computed code based on the Generalized Archie's Law and available data from boreholes were used to relate the obtained geoelectrical model to rock properties (i.e. porosity and permeability). The results are compared to independent geological and geophysical data for superior interpretation.

  16. Solar wind monitor—a school geophysics project

    Science.gov (United States)

    Robinson, Ian

    2018-05-01

    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 real-time uploading data and graphs to a website every few minutes. Modular design encourages construction and testing by teams of students as well as expansion and refinement. The system has been tested running unattended for months at a time. Both the hardware design and software is published as open-source [1, 10].

  17. Common interests bind AGU and geophysical groups around the globe

    Science.gov (United States)

    McEntee, Christine

    2012-02-01

    In continuation of our work to strengthen alliances with key organizations in the Earth and space science community, AGU president Michael McPhaden, president-elect Carol Finn, and I held a series of meetings with leaders from other science societies during the 2011 Fall Meeting. Over the course of 2 days we met with leaders from the Geophysical Society of America, European Geosciences Union, Japan Geosciences Union, Ethiopian Geophysical Union, Asia Oceania Geosciences Society, Chinese Geophysical Society, and Asociación Latinoamericana de Geofísica Espacial. This gave us a valued opportunity to discuss the common interests and challenges we all face and to learn from each other's experience. The meetings allowed AGU to strengthen existing cooperative agreements and reach new levels of understanding between us and other societies. Additionally, we met with representatives from the Korean Ocean Research and Development Institute to discuss their intention to establish a geophysical union modeled after AGU.

  18. Technical note: Application of geophysical tools for tree root studies in forest ecosystems in complex soils

    Directory of Open Access Journals (Sweden)

    U. Rodríguez-Robles

    2017-11-01

    Full Text Available While semiarid forests frequently colonize rocky substrates, knowledge is scarce on how roots garner resources in these extreme habitats. The Sierra San Miguelito Volcanic Complex in central Mexico exhibits shallow soils and impermeable rhyolitic-rock outcrops, which impede water movement and root placement beyond the soil matrix. However, rock fractures, exfoliated rocks and soil pockets potentially permit downward water percolation and root growth. With ground-penetrating radar (GPR and electrical resistivity tomography (ERT, two geophysical methods advocated by Jayawickreme et al. (2014 to advance root ecology, we advanced in the method development studying root and water distribution in shallow rocky soils and rock fractures in a semiarid forest. We calibrated geophysical images with in situ root measurements, and then extrapolated root distribution over larger areas. Using GPR shielded antennas, we identified both fine and coarse pine and oak roots from 0.6 to 7.5 cm diameter at different depths into either soil or rock fractures. We also detected, trees anchoring their trunks using coarse roots underneath rock outcroppings. With ERT, we tracked monthly changes in humidity at the soil–bedrock interface, which clearly explained spatial root distribution of both tree species. Geophysical methods have enormous potential in elucidating root ecology. More interdisciplinary research could advance our understanding in belowground ecological niche functions and their role in forest ecohydrology and productivity.

  19. A review of geophysical investigations at the site of Chalk River Nuclear Laboratories, Ontario

    International Nuclear Information System (INIS)

    Thomas, M.D.; Hayles, J.G.

    1988-01-01

    The site of the Chalk River Nuclear Laboratories was one of the first research areas located on crystalline rocks to be extensively investigated under the Canadian Nuclear Fuel Waste Management Program. A large contribution to meeting the geoscientific objectives of the program has been made using a suite of geophysical techniques. Many of them are standard, though sometimes modified in terms of instrumentation and/or experimental and/or analytical procedures, to meet the particular needs of the waste management program. Relatively new techniques have also been employed. Much of the early evaluation and development of the various techniques took place at the Chalk River site. Standard methods such as gravity, magnetics and seismic sounding have been used to investigate bedrock structure, and the seismic method has also been used to estimate overburden thickness. Standard geophysical borehole logging has been used to obtain in situ estimates of physical properties, to locate fracture zones and to make hole to hole correlations that have helped define local structure. Several standard electrical (e.g. resitivity) and electromagnetic (e.g. VLF-EM) techniques have proven successful in identifying water-filled fractures and faults. Relatively new techniques introduced into the geophysics at Chalk River were: ground probing radar; to investigate overburden; borehole TV and acoustic televiewer and VLF-EM, to locate fractures; studies of seismic tube-waves, well tides and temperature logs, to investigate fracture location and permeability. Most of these methods have been successful and are now routinely employed at other research sites

  20. Geophysical logging for groundwater investigations in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Phongpiyah Klinmanee

    2012-09-01

    Full Text Available In Thailand the Department of Groundwater Resources is drilling to find vital aquifers. Sometimes groundwater formations cannot be identified clearly during drilling; therefore, geophysical logging was applied after drilling and before casing.The tool used here is measuring nine parameters in one run, natural gamma ray, spontaneous potential, single point resistance, normal resistivity (AM 8’’, 16’’, 32’’, and 64’’, mud temperature and resistivity. Cutting was used to support the geophysical interpretations. In many cases the groundwater bearing zones could be clearly identified. The combination of andthe possibility choosing from nine parameters measured provided the necessary data base to identify groundwater bearingzones in different environments. It has been demonstrated that in different wells different tools are favorable than others.Based on the conclusions of this study geophysical logging in groundwater exploration is recommended as a normalstandard technique that should be applied in every new well drilled.

  1. Preliminary evaluation of alterant geophysical tomography in welded tuff

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Daily, W.D.

    1985-01-01

    The ability of alterant geophysical tomography to delineate flow paths in a welded tuff rock mass has been preliminarily evaluated based on the results of a field experiment. Electromagnetic measurements were made before, during and after a water-based, dye tracer flowed through the rock mass. Alterant geophysical tomographs were generated and compared with independent evidence - borescope logs, neutron logs and dyed rock samples. Anomalies present in the tomograph match the location and orientation of fractures mapped with a borescope. The location of tracer-stained fractures coincides with the location of some image anomalies; other geophysical anomalies exist where tracer-stained fractures were not observed, perhaps due to poor core recovery. Additional drilling to locate stained flow paths and other experiments are planned so that the applicability of the technique can be further evaluated

  2. Improved estimation of hydraulic conductivity by combining stochastically simulated hydrofacies with geophysical data.

    Science.gov (United States)

    Zhu, Lin; Gong, Huili; Chen, Yun; Li, Xiaojuan; Chang, Xiang; Cui, Yijiao

    2016-03-01

    Hydraulic conductivity is a major parameter affecting the output accuracy of groundwater flow and transport models. The most commonly used semi-empirical formula for estimating conductivity is Kozeny-Carman equation. However, this method alone does not work well with heterogeneous strata. Two important parameters, grain size and porosity, often show spatial variations at different scales. This study proposes a method for estimating conductivity distributions by combining a stochastic hydrofacies model with geophysical methods. The Markov chain model with transition probability matrix was adopted to re-construct structures of hydrofacies for deriving spatial deposit information. The geophysical and hydro-chemical data were used to estimate the porosity distribution through the Archie's law. Results show that the stochastic simulated hydrofacies model reflects the sedimentary features with an average model accuracy of 78% in comparison with borehole log data in the Chaobai alluvial fan. The estimated conductivity is reasonable and of the same order of magnitude of the outcomes of the pumping tests. The conductivity distribution is consistent with the sedimentary distributions. This study provides more reliable spatial distributions of the hydraulic parameters for further numerical modeling.

  3. Joint inversion of geophysical and hydrological data for improved subsurface characterization

    International Nuclear Information System (INIS)

    Kowalsky, Michael B.; Chen, Jinsong; Hubbard, Susan S.

    2006-01-01

    Understanding fluid distribution and movement in the subsurface is critical for a variety of subsurface applications, such as remediation of environmental contaminants, sequestration of nuclear waste and CO2, intrusion of saline water into fresh water aquifers, and the production of oil and gas. It is well recognized that characterizing the properties that control fluids in the subsurface with the accuracy and spatial coverage needed to parameterize flow and transport models is challenging using conventional borehole data alone. Integration of conventional borehole data with more spatially extensive geophysical data (obtained from the surface, between boreholes, and from surface to boreholes) shows promise for providing quantitative information about subsurface properties and processes. Typically, estimation of subsurface properties involves a two-step procedure in which geophysical data are first inverted and then integrated with direct measurements and petrophysical relationship information to estimate hydrological parameters. However, errors inherent to geophysical data acquisition and inversion approaches and errors associated with petrophysical relationships can decrease the value of geophysical data in the estimation procedure. In this paper, we illustrate using two examples how joint inversion approaches, or simultaneous inversion of geophysical and hydrological data, offer great potential for overcoming some of these limitations

  4. BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.

    Science.gov (United States)

    Seeley, Robert L.; Daniels, Jeffrey J.

    1984-01-01

    A system has been developed to simultaneously sample and transmit digital data from five remote geophysical data receiver stations to a control station that processes, displays, and stores the data. A microprocessor in each remote station receives commands from the control station over a single telemetry channel.

  5. Geophysics, Remote Sensing, and the Comprehensive Nuclear-Test-Ban Treaty (CTBT) Integrated Field Exercise 2014

    Science.gov (United States)

    Sussman, A. J.; Macleod, G.; Labak, P.; Malich, G.; Rowlands, A. P.; Craven, J.; Sweeney, J. J.; Chiappini, M.; Tuckwell, G.; Sankey, P.

    2015-12-01

    The Integrated Field Exercise of 2014 (IFE14) was an event held in the Hashemite Kingdom of Jordan (with concurrent activities in Austria) that tested the operational and technical capabilities of an on-site inspection (OSI) within the CTBT verification regime. During an OSI, up to 40 international inspectors will search an area for evidence of a nuclear explosion. Over 250 experts from ~50 countries were involved in IFE14 (the largest simulation of a real OSI to date) and worked from a number of different directions, such as the Exercise Management and Control Teams (which executed the scenario in which the exercise was played) and those participants performing as members of the Inspection Team (IT). One of the main objectives of IFE14 was to test and integrate Treaty allowed inspection techniques, including a number of geophysical and remote sensing methods. In order to develop a scenario in which the simulated exercise could be carried out, suites of physical features in the IFE14 inspection area were designed and engineered by the Scenario Task Force (STF) that the IT could detect by applying the geophysical and remote sensing inspection technologies, in addition to other techniques allowed by the CTBT. For example, in preparation for IFE14, the STF modeled a seismic triggering event that was provided to the IT to prompt them to detect and localize aftershocks in the vicinity of a possible explosion. Similarly, the STF planted shallow targets such as borehole casings and pipes for detection using other geophysical methods. In addition, airborne technologies, which included multi-spectral imaging, were deployed such that the IT could identify freshly exposed surfaces, imported materials, and other areas that had been subject to modification. This presentation will introduce the CTBT and OSI, explain the IFE14 in terms of the goals specific to geophysical and remote sensing methods, and show how both the preparation for and execution of IFE14 meet those goals.

  6. Geophysical borehole logging and optical imaging of the pilot hole ONK-PH2

    International Nuclear Information System (INIS)

    Lahti, M.; Heikkinen, E.

    2005-01-01

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of pilot hole ONK-PH2 in ONKALO tunnel at the Olkiluoto site in December 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all the surveys, integration of the data as well as interpretation of the acoustic and borehole radar data. The report describes the field operation, equipment, processing procedures, interpretation results and shows the obtained geophysical and image data. The data as well as the interpretation results are delivered digitally in WellCAD and Excel format. (orig.)

  7. Geophysical borehole logging and optical imaging of the pilot hole ONK-PH2

    Energy Technology Data Exchange (ETDEWEB)

    Lahti, M. [Suomen Malmi Oy, Espoo (Finland); Heikkinen, E. [JP-Fintact Oy, Vantaa (Finland)

    2005-01-15

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of pilot hole ONK-PH2 in ONKALO tunnel at the Olkiluoto site in December 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all the surveys, integration of the data as well as interpretation of the acoustic and borehole radar data. The report describes the field operation, equipment, processing procedures, interpretation results and shows the obtained geophysical and image data. The data as well as the interpretation results are delivered digitally in WellCAD and Excel format. (orig.)

  8. Eneolithic mine Prljuša: Mali Šturac archaeological and geophysical investigations

    Directory of Open Access Journals (Sweden)

    Antonović Dragana

    2012-01-01

    Full Text Available The Eneolithic copper mine at Mali Šturac was discovered in 1980 and subsequently investigated to a smaller extent from 1981 to 1987. In 2010 the investigations at Prljuša were reactivated with the aim of defining how much and how long the mine had been exploited during prehistory. Pilot geophysical studies were followed by more extensive explorations in 2011. They focused on a zone related to Shafts 4 and 6, discovered in 1987. The geophysical explorations have comprised the methods of selfpotential - SP, electrical scanning - ES and seismic profiling with one geophone - SGRP. The explorations covered a surface of 400 m² including five sections, each 50 m long, with 2 m intervals between them. These investigations identified underground channels in Shaft 4 and Shaft 6. Three meters below Shaft 4, a large underground gallery was found and in the continuation of the entrance of Shaft 6, a 10 m long horizontal channel was detected. Northwards from Shaft 4 and Shaft 6, at a distance of 6-8 m, at least six mining shafts were detected. However, they are not visible on the surface because their entrances are filled with loose material. The investigations carried out in 2011 proved that geophysical investigations are an efficient method for studying old mining works and, therefore, it has been decided to continue with this type of exploration. [Projekat Ministarstva nauke Republike Srbije, br. 177020: Archaeology of Serbia: cultural identity, integration factors, technological processes and the role of the Central Balkans in the development of European prehistory i br. 177023: Cultural changes and population movements in the early prehistory of the Central Balkans

  9. Geophysical Exploration Technologies for the Deep Lithosphere Research: An Education Materials for High School Students

    Science.gov (United States)

    Xu, H.; Xu, C.; Luo, S.; Chen, H.; Qin, R.

    2012-12-01

    The science of Geophysics applies the principles of physics to study of the earth. Geophysical exploration technologies include the earthquake seismology, the seismic reflection and refraction methods, the gravity method, the magnetic method and the magnetotelluric method, which are used to measure the interior material distribution, their structure and the tectonics in the lithosphere of the earth. Part of the research project in SinoProbe-02-06 is to develop suitable education materials for carton movies targeting the high school students and public. The carton movies include five parts. The first part includes the structures of the earth's interior and variation in their physical properties that include density, p-wave, s-wave and so on, which are the fundamentals of the geophysical exploration technologies. The second part includes the seismology that uses the propagation of elastic waves through the earth to study the structure and the material distribution of the earth interior. It can be divided into earthquake seismology and artifice seismics commonly using reflection and refraction. The third part includes the magnetic method. Earth's magnetic field (also known as the geomagnetic field)extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun. The aim of magnetic survey is to investigate subsurface geology on the basis of anomalies in the Earth's magnetic field resulting from the magnetic properties of the underlying rocks. The magnetic method in the lithosphere attempts to use magnetic disturbance to analyse the regional geological structure and the magnetic boundaries of the crust. The fourth part includes the gravity method. A gravity anomaly results from the inhomogeneous distribution of density of the Earth. Usually gravity anomalies contain superposed anomalies from several sources. The long wave length anomalies due to deep density contrasts are called regional anomalies. They are

  10. Environmental assessment of a uranium experimental rock blasting in Portugal, using geophysical and hydrogeological methods

    International Nuclear Information System (INIS)

    Ramalho, E C; Midões, C; Costa, A; Lourenço, M C; Monteiro Santos, F A

    2012-01-01

    The Nisa uranium deposit, located in Central Portugal, has been known since the late 1960s. Some areas were explored at that time. Today, a few open pits and dumps remain in place and are a concern to local authorities. To assess the geoenvironmental problems caused by the main mining exploration composed of an experimental rock blasting, 3D electrical conductivity and resistivity models were made to develop a hydrogeological model to understand the possibility of contaminants transportation, such as uranium, from the dumps towards a dam located nearby. These 3D models were the support to show alteration layer thickness variations and fault zones at depths controlling groundwater circulation. Spectrometric surveys were also carried out and correlated with geology and geoelectrical structure. All this information was used in the construction of the 3D steady state hydrogeological model of the experimental rock blasting of Nisa. In this model, groundwater flow and the contaminant pathways were simulated. Some areas have very high radioactive values resulting from the geological formation characteristics and old dumps. However, results of the environmental assessment using geophysical and hydrogeological methods point to a critical situation restricted only to the area of the experimental rock blasting of the Nisa uranium deposit and its dumps. (paper)

  11. Characterisation of the heterogeneity of karst using electrical geophysics - applications in SW China

    Science.gov (United States)

    Binley, A. M.; Cheng, Q.; Tao, M.; Chen, X.

    2017-12-01

    The southwest China karst region is one of the largest globally continuous karst areas. The great (structural, hydrological and geochemical) complexity of karstic environments and their rapidly evolving nature make them extremely vulnerable to natural and anthropogenic processes/activities. Characterising the location and properties of structures within the karst critical zone, and understanding how the landform is evolving is essential for the mitigation and adaption to locally- and globally-driven changes. Because of the specific nature of karst geology and geomorphology in the humid tropics and subtropics, spatial heterogeneity is high, evidenced by specific landforms features. Such heterogeneity leads to a high dynamic variability of hydrological processes in space and time, along with a complex exchange of surface water and groundwater. Investigating karst hydrogeological features is extremely challenging because of the three-dimensional nature of the system. Observations from boreholes can vary significantly over several metres, making conventional aquifer investigative methods limited. Geophysical methods have emerged as potentially powerful tools for hydrogeological investigations. Geophysical surveys can help to obtain more insight into the complex conduit networks and depth of weathering, both of which can provide quantitative information about the hydrological and hydrochemical dynamics of the system, in addition to providing a better understanding of how critical zone structures have been established and how the landscape is evolving. We present here results from recent geophysical field campaigns in SW China. We illustrate the effectiveness of electrical methods for mapping soil infil in epikarst and report results from field-based investigations along hillslope and valley transects. Our results reveal distinct zones of relatively high electrical conductivity to depths of tens of metres, which we attribute to localised increased fracture density. We

  12. Geophysical investigation of trench 4, Burial Ground 218-W-4C, 200 west area

    International Nuclear Information System (INIS)

    Kiesler, J.P.

    1994-01-01

    This report contains the results of a geophysical investigation conducted to characterize Trench 4, located in Burial Ground 218-W-4C, 200 West Area. Trench 4 is where transuranic (TRU) waste is stored. The primary objective of these geophysical investigations was to determine the outer edges of the trench/modules and select locations for plate-bearing tests. The test locations are to be 5 to 8 ft. beyond the edges of the trench. Secondary objectives include differentiating between the different types of waste containers within a given trench, determining the amount of soil cover over the waste containers, and to locate the module boundaries. Ground-penetrating radar (GPR) and electromagnetic induction (EMI) were the methods selected for this investigation

  13. Object-Oriented Programming When Developing Software in Geology and Geophysics

    Science.gov (United States)

    Ahmadulin, R. K.; Bakanovskaya, L. N.

    2017-01-01

    The paper reviews the role of object-oriented programming when developing software in geology and geophysics. Main stages have been identified at which it is worthwhile to apply principles of object-oriented programming when developing software in geology and geophysics. The research was based on a number of problems solved in Geology and Petroleum Production Institute. Distinctive features of these problems are given and areas of application of the object-oriented approach are identified. Developing applications in the sphere of geology and geophysics has shown that the process of creating such products is simplified due to the use of object-oriented programming, firstly when designing structures for data storage and graphical user interfaces.

  14. A multi-scale permafrost investigation along the Alaska Highway Corridor based on airborne electromagnetic and auxiliary geophysical data

    Science.gov (United States)

    Minsley, B. J.; Kass, M. A.; Bloss, B.; Pastick, N.; Panda, S. K.; Smith, B. D.; Abraham, J. D.; Burns, L. E.

    2012-12-01

    More than 8000 square kilometers of airborne electromagnetic (AEM) data were acquired along the Alaska Highway Corridor in 2005-2006 by the Alaska Department of Natural Resources Division of Geological and Geophysical Surveys. Because this large AEM dataset covers diverse geologic and permafrost settings, it is an excellent testbed for studying the electrical geophysical response from a wide range of subsurface conditions. These data have been used in several recent investigations of geology, permafrost, and infrastructure along the highway corridor. In this study, we build on existing interpretations of permafrost features by re-inverting the AEM data using traditional least squares inversion techniques as well as recently developed stochastic methods aimed at quantifying uncertainty in geophysical data. Ground-based geophysical measurements, including time-domain electromagnetic soundings, surface nuclear magnetic resonance soundings, and shallow frequency-domain electromagnetic profiles, have also been acquired to help validate and extend the AEM interpretations. Here, we focus on the integration of different types of data to yield an improved characterization of permafrost, including: methods to discriminate between geologic and thermal controls on resistivity; identifying relationships between shallow resistivity and active layer thickness by incorporating auxiliary remote sensing data and ground-based measurements; quantifying apparent slope-aspect-resistivity relationships, where south-facing slopes appear less resistive than north-facing slopes within similar geologic settings; and investigating an observed decrease in resistivity beneath several areas associated with recent fires.

  15. Near Surface Geophysical Methods Applied to the Rising Star Cave System

    Science.gov (United States)

    Webb, S. J.; Naidoo, M.; Elliott, M. C.; Kruger, A.; Roberts, E.; Dirks, P.

    2017-12-01

    The Rising Star Cave system is located approximately 40 km northwest of Johannesburg in the Malmani dolomites (Chuniespoort group,Transvaal Supergroup). The cave system is extensive with 4 km of mapped passages and chambers. The Dinaledi chamber, host to the Homo Naledi fossils, is reached by following a tortuous route with squeezes as small as 20 cm. The chamber is located 30 m below surface and 80 m from the entrance. The enigmatic find of fossils from at least 15 individual hominins, without the presence of other species, led to the idea of deliberate burial. The present access route is difficult and it is unclear how early hominins were able to navigate it, prompting the suggestion of an undiscovered entrance. We are using near surface geophysical methods to investigate possible connections between the surface and the caves. Using a Geometrics Cs-vapor Walkmag, we collected preliminary ground magnetic intensity measurements over a region 300 m x 200 m, using 1 m station spacing and 10 m line spacing. The average magnetic variation along line is 200 nT. We also collected over 100 susceptibility measurements on outcropping lithologies, surface soil and cave sediments using a SM-30 susceptibility meter. The surface soil was one to two orders of magnitude higher than surrounding lithologies (average = 1.5 x 10-3 SI) and the cave sediment samples were slightly higher (average = 3.07 x 10-3 SI). We were able to collect GPR data (GSSI SIR-3000, 400 MHz) in selected spots on the cave floor with the goal of locating the cave floor beneath the sediments. Dolomites usually have low magnetic susceptibilities, but erosion products of the nearby magnetic Hospital Hill or Rooihoogte shales may have been transported into or onto the cave system. This is a likely cause of the magnetic anomalies and larger amplitude anomalies may indicate an accumulation of sediments, extending to depth. These anomalies will be further investigated using gravity to determine if there are

  16. Comparing plume characteristics inferred from cross-borehole geophysical data

    DEFF Research Database (Denmark)

    Haarder, Eline Bojsen; Binley, Andrew; Zibar, Majken Caroline Looms

    2012-01-01

    significantly influences results of the moment analysis. We compare results of three cross-borehole geophysical approaches for imaging tracer migration arising from a point injection of water in the unsaturated zone: three-dimensional electrical resistivity tomography (ERT), two-dimensional ground......-penetrating radar (GPR) tomography and quasi-three-dimensional GPR tomography. In the studied field experiment, a tracer was injected for a period of 5 d and was monitored both during injection and for 5 d during the subsequent redistribution. The three methods show similar characteristics of the plume development...

  17. The examination of the spread of the leachates coming out of a solid waste disposal area on the ground with geophysical and geochemical methods (Sivas, Turkey)

    Science.gov (United States)

    Özel, Sevda; Yılmaz, Ali; Emin Candansayar, M.

    2017-03-01

    This study has been conducted in the irregular solid waste disposal area in the city of Sivas. The pollution spread formed by the leachates coming out of the disposal area has been examined with geophysical and geochemical works in this study. For this reason, the spread of the leachate pollution expanding in different geological units at both sides of a creek on the ground has been examined. For this purpose, the pollution spread has been examined with the methods of Direct Current Resistivity (DCR) and Electromagnetic Conductivity (EMC) and soil analyses. In the DCR method, 2D inversion of each sounding-profile datum measured alongside the lines parallel to each other and 3D inversion of the data measured in all the lines have been used in the interpretations. Apparent conductivity map has been attained from EMC measurements. The results of heavy metal analyses in the soil samples taken alongside the Haçin Creek have been assessed with the Spider diagram method. It has been determined that the flow of the leachate from geophysical models is in a SE direction and towards Kızılırmak and it continues vertically deeper than 4 m. In addition, it has been understood that the flow direction of the leachate is inspected by the geological structures. It has been understood from the geochemical results that the pollution in the soil stems from the leachate. In this way, it has been observed that the underground and surface water resources in the territory are under the threat of the pollution occurring due to the leachate.

  18. 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

  19. Improving Discoverability of Geophysical Data using Location Based Services

    Science.gov (United States)

    Morrison, D.; Barnes, R. J.; Potter, M.; Nylund, S. R.; Patrone, D.; Weiss, M.; Talaat, E. R.; Sarris, T. E.; Smith, D.

    2014-12-01

    The great promise of Virtual Observatories is the ability to perform complex search operations across the metadata of a large variety of different data sets. This allows the researcher to isolate and select the relevant measurements for their topic of study. The Virtual ITM Observatory (VITMO) has many diverse geophysical datasets that cover a large temporal and spatial range that present a unique search problem. VITMO provides many methods by which the user can search for and select data of interest including restricting selections based on geophysical conditions (solar wind speed, Kp, etc) as well as finding those datasets that overlap in time. One of the key challenges in improving discoverability is the ability to identify portions of datasets that overlap in time and in location. The difficulty is that location data is not contained in the metadata for datasets produced by satellites and would be extremely large in volume if it were available, making searching for overlapping data very time consuming. To solve this problem we have developed a series of light-weight web services that can provide a new data search capability for VITMO and others. The services consist of a database of spacecraft ephemerides and instrument fields of view; an overlap calculator to find times when the fields of view of different instruments intersect; and a magnetic field line tracing service that maps in situ and ground based measurements to the equatorial plane in magnetic coordinates for a number of field models and geophysical conditions. These services run in real-time when the user queries for data. They will allow the non-specialist user to select data that they were previously unable to locate, opening up analysis opportunities beyond the instrument teams and specialists, making it easier for future students who come into the field.

  20. Critical zone architecture and processes: a geophysical perspective

    Science.gov (United States)

    Holbrook, W. S.

    2016-12-01

    The "critical zone (CZ)," Earth's near-surface layer that reaches from treetop to bedrock, sustains terrestrial life by storing water and producing nutrients. Despite is central importance, however, the CZ remains poorly understood, due in part to the complexity of interacting biogeochemical and physical processes that take place there, and in part due to the difficulty of measuring CZ properties and processes at depth. Major outstanding questions include: What is the architecture of the CZ? How does that architecture vary across scales and across gradients in climate, lithology, topography, biology and regional states of stress? What processes control the architecture of the CZ? At what depth does weathering initiate, and what controls the rates at which it proceeds? Based on recent geophysical campaigns at seven Critical Zone Observatory (CZO) sites and several other locations, a geophysical perspective on CZ architecture and processes is emerging. CZ architecture can be usefully divided into four layers, each of which has distinct geophysical properties: soil, saprolite, weathered bedrock and protolith. The distribution of those layers across landscapes varies depending on protolith composition and internal structure, topography, climate (P/T) and the regional state of stress. Combined observations from deep CZ drilling, geophysics and geochemistry demonstrate that chemical weathering initiates deep in the CZ, in concert with mechanical weathering (fracturing), as chemical weathering appears concentrated along fractures in borehole walls. At the Calhoun CZO, the plagioclase weathering front occurs at nearly 40 m depth, at the base of a 25-m-thick layer of weathered bedrock. The principal boundary in porosity, however, occurs at the saprolite/weathered bedrock boundary: porosity decreases over an order of magnitude, from 50% to 5% over an 8-m-thick zone at the base of saprolite. Porosity in weathered bedrock is between 2-5%. Future progress will depend on (1

  1. Recent achievements and trends of research for geophysical prospection of archaeological sites

    International Nuclear Information System (INIS)

    Aubry, L.; Benech, C.; Hesse, A.

    2001-01-01

    Our times are characterized by an increasing need for prospection particularly within the context of rescue archaeology. Geophysics has an important part to play due to its ability to identify some well defined targets as well as to investigate large areas. Several recent surveys, using carefully selected methods chosen in accordance with the type of expected remain or a combination of methods in order to refine or confirm the interpretation, have demonstrated the expertise of several organisations in a wide variety of archaeological contexts. However, important improvements are still to be expected from the laboratories. Our team, working within the framework of three dissertations, is investigating several original subjects, for which the initial results are presented and discussed here: (1) The use of magnetic susceptibility measurements on wide mesh grids in order to survey extensive areas immediately prior to their occupation or destruction by large modern equipment; (2) Experiments to test a new survey device (Slingram - CS150) able to measure the magnetic susceptibility of the ground; (3) Interpretation of a series of geophysical measurements integrated with other types of data into a G.I.S. (author)

  2. The Legacy of Benoit Mandelbrot in Geophysics

    Science.gov (United States)

    Turcotte, D. L.

    2001-12-01

    The concept of fractals (fractional dimension) was introduced by Benoit Mandelbrot in his famous 1967 Science paper. The initial application was to the length of the coastline of Britain. A milestone in the appreciation of the fractal concept by geophysicists was the Union session of the AGU on fractals led off by Benoit in 1986. Although fractals have found important applications in almost every branch of the physical, biological, and social sciences, fractals have been particularly useful in geophysics. Drainage networks are fractal. The frequency-magnitude distribution of earthquakes is fractal. The scale invariance of landscapes and many other geological processes is due to the applicability of power-law (fractal) distributions. Clouds are often fractal. Porosity distributions are fractal. In an almost independent line of research, Benoit in collaboration with James Wallace and others developed the concept of self-affine fractals. The original applications were primarily to time series in hydrology and built on the foundation laid by Henry Hurst. Fractional Gaussian noises and fractional Brownian motions are ubiquitous in geophysics. These are expressed in terms of the power-law relation between the power-spectral density S and frequency f, S ~ f{ β }, examples are β = 0 (white noise), β = 1 (1/f noise), β = 2 (Brownian motion). Of particular importance in geophysics are fractional noises with β = 0.5, these are stationary but have long-range persistent and have a Hurst exponent H = 0.7. Examples include river flows, tree rings, sunspots, varves, etc. Two of Benoit Mandelbrot's major contributions in geophysics as in other fields are: (1) an appreciation of the importance of fat-tail, power-law (fractal) distributions and (2) an appreciation of the importance of self-similar long-range persistence in both stationary time series (noises) and nonstationary time series (walks).

  3. Basin Characterisation by Means of Joint Inversion of Electromagnetic Geophysical Data, Borehole Data and Multivariate Statistical Methods: The Loop Head Peninsula, Western Ireland, Case Study

    Science.gov (United States)

    Campanya, J. L.; Ogaya, X.; Jones, A. G.; Rath, V.; McConnell, B.; Haughton, P.; Prada, M.

    2016-12-01

    The Science Foundation Ireland funded project IRECCSEM project (www.ireccsem.ie) aims to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic geophysical data with existing geophysical and geological data. One of the objectives of this component of IRECCSEM is to characterise the subsurface beneath the Loop Head Peninsula (part of Clare Basin, Co. Clare, Ireland), and identify major electrical resistivity structures that can guide an interpretation of the carbon sequestration potential of this area. During the summer of 2014, a magnetotelluric (MT) survey was carried out on the Loop Head Peninsula, and data from a total of 140 sites were acquired, including audio-magnetotelluric (AMT), and broadband magnetotelluric (BBMT). The dataset was used to generate shallow three-dimensional (3-D) electrical resistivity models constraining the subsurface to depths of up to 3.5 km. The three-dimensional (3-D) joint inversions were performed using three different types of electromagnetic data: MT impedance tensor (Z), geomagnetic transfer functions (T), and inter-station horizontal magnetic transfer-functions (H). The interpretation of the results was complemented with second-derivative models of the resulting electrical resistivity models, and a quantitative comparison with borehole data using multivariate statistical methods. Second-derivative models were used to define the main interfaces between the geoelectrical structures, facilitating superior comparison with geological and seismic results, and also reducing the influence of the colour scale when interpreting the results. Specific analysis was performed to compare the extant borehole data with the electrical resistivity model, identifying those structures that are better characterised by the resistivity model. Finally, the electrical resistivity model was also used to propagate some of the physical properties measured in the borehole, when a good relation was

  4. 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

  5. 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...

  6. Machine Learning Methods for Identifying Composition of Uranium Deposits in Kazakhstan

    Directory of Open Access Journals (Sweden)

    Kuchin Yan

    2017-12-01

    Full Text Available The paper explores geophysical methods of wells survey, as well as their role in the development of Kazakhstan’s uranium deposit mining efforts. An analysis of the existing methods for solving the problem of interpreting geophysical data using machine learning in petroleum geophysics is made. The requirements and possible applications of machine learning methods in regard to uranium deposits of Kazakhstan are formulated in the paper.

  7. 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...

  8. 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...

  9. Genetic algorithms and their use in Geophysical Problems

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Paul B. [Univ. of California, Berkeley, CA (United States)

    1999-04-01

    Genetic algorithms (GAs), global optimization methods that mimic Darwinian evolution are well suited to the nonlinear inverse problems of geophysics. A standard genetic algorithm selects the best or ''fittest'' models from a ''population'' and then applies operators such as crossover and mutation in order to combine the most successful characteristics of each model and produce fitter models. More sophisticated operators have been developed, but the standard GA usually provides a robust and efficient search. Although the choice of parameter settings such as crossover and mutation rate may depend largely on the type of problem being solved, numerous results show that certain parameter settings produce optimal performance for a wide range of problems and difficulties. In particular, a low (about half of the inverse of the population size) mutation rate is crucial for optimal results, but the choice of crossover method and rate do not seem to affect performance appreciably. Optimal efficiency is usually achieved with smaller (< 50) populations. Lastly, tournament selection appears to be the best choice of selection methods due to its simplicity and its autoscaling properties. However, if a proportional selection method is used such as roulette wheel selection, fitness scaling is a necessity, and a high scaling factor (> 2.0) should be used for the best performance. Three case studies are presented in which genetic algorithms are used to invert for crustal parameters. The first is an inversion for basement depth at Yucca mountain using gravity data, the second an inversion for velocity structure in the crust of the south island of New Zealand using receiver functions derived from teleseismic events, and the third is a similar receiver function inversion for crustal velocities beneath the Mendocino Triple Junction region of Northern California. The inversions demonstrate that genetic algorithms are effective in solving problems

  10. 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...

  11. Learning about hydrothermal volcanic activity by modeling induced geophysical changes

    Science.gov (United States)

    Currenti, Gilda M.; Napoli, Rosalba

    2017-05-01

    Motivated by ongoing efforts to understand the nature and the energy potential of geothermal resources, we devise a coupled numerical model (hydrological, thermal, mechanical), which may help in the characterization and monitoring of hydrothermal systems through computational experiments. Hydrothermal areas in volcanic regions arise from a unique combination of geological and hydrological features which regulate the movement of fluids in the vicinity of magmatic sources capable of generating large quantities of steam and hot water. Numerical simulations help in understanding and characterizing rock-fluid interaction processes and the geophysical observations associated with them. Our aim is the quantification of the response of different geophysical observables (i.e. deformation, gravity and magnetic field) to hydrothermal activity on the basis of a sound geological framework (e.g. distribution and pathways of the flows, the presence of fractured zones, caprock). A detailed comprehension and quantification of the evolution and dynamics of the geothermal systems and the definition of their internal state through a geophysical modeling approach are essential to identify the key parameters for which the geothermal system may fulfill the requirements to be exploited as a source of energy. For the sake of illustration only, the numerical computations are focused on a conceptual model of the hydrothermal system of Vulcano Island by simulating a generic 1-year unrest and estimating different geophysical changes. We solved (i) the mass and energy balance equations of flow in porous media for temperature, pressure and density changes, (ii) the elastostatic equation for the deformation field and (iii) the Poisson’s equations for gravity and magnetic potential fields. Under the model assumptions, a generic unrest of 1-year engenders on the ground surface low amplitude changes in the investigated geophysical observables, that are, however, above the accuracies of the modern

  12. Learning about Hydrothermal Volcanic Activity by Modeling Induced Geophysical Changes

    Directory of Open Access Journals (Sweden)

    Gilda M. Currenti

    2017-05-01

    Full Text Available Motivated by ongoing efforts to understand the nature and the energy potential of geothermal resources, we devise a coupled numerical model (hydrological, thermal, mechanical, which may help in the characterization and monitoring of hydrothermal systems through computational experiments. Hydrothermal areas in volcanic regions arise from a unique combination of geological and hydrological features which regulate the movement of fluids in the vicinity of magmatic sources capable of generating large quantities of steam and hot water. Numerical simulations help in understanding and characterizing rock-fluid interaction processes and the geophysical observations associated with them. Our aim is the quantification of the response of different geophysical observables (i.e., deformation, gravity, and magnetic fields to hydrothermal activity on the basis of a sound geological framework (e.g., distribution and pathways of the flows, the presence of fractured zones, caprock. A detailed comprehension and quantification of the evolution and dynamics of the geothermal systems and the definition of their internal state through a geophysical modeling approach are essential to identify the key parameters for which the geothermal system may fulfill the requirements to be exploited as a source of energy. For the sake of illustration only, the numerical computations are focused on a conceptual model of the hydrothermal system of Vulcano Island by simulating a generic 1-year unrest and estimating different geophysical changes. We solved (i the mass and energy balance equations of flow in porous media for temperature, pressure and density changes, (ii the elastostatic equation for the deformation field and (iii the Poisson's equations for gravity and magnetic potential fields. Under the model assumptions, a generic unrest of 1-year engenders on the ground surface low amplitude changes in the investigated geophysical observables, that, being above the accuracies of

  13. Application of Surface Geophysical Methods, With Emphasis on Magnetic Resonance Soundings, to Characterize the Hydrostratigraphy of the Brazos River Alluvium Aquifer, College Station, Texas, July 2006 - A Pilot Study

    Science.gov (United States)

    Shah, Sachin D.; Kress, Wade H.; Legchenko, Anatoly

    2007-01-01

    The U.S. Geological Survey, in cooperation with the Texas Water Development Board, used surface geophysical methods at the Texas A&M University Brazos River Hydrologic Field Research Site near College Station, Texas, in a pilot study, to characterize the hydrostratigraphic properties of the Brazos River alluvium aquifer and determine the effectiveness of the methods to aid in generating an improved ground-water availability model. Three non-invasive surface geophysical methods were used to characterize the electrical stratigraphy and hydraulic properties and to interpret the hydrostratigraphy of the Brazos River alluvium aquifer. Two methods, time-domain electromagnetic (TDEM) soundings and two-dimensional direct-current (2D-DC) resistivity imaging, were used to define the lateral and vertical extent of the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the underlying Yegua Formation. Magnetic resonance sounding (MRS), a recently developed geophysical method, was used to derive estimates of the hydrologic properties including percentage water content and hydraulic conductivity. Results from the geophysics study demonstrated the usefulness of combined TDEM, 2D-DC resistivity, and MRS methods to reduce the need for additional boreholes in areas with data gaps and to provide more accurate information for ground-water availability models. Stratigraphically, the principal finding of this study is the relation between electrical resistivity and the depth and thickness of the subsurface hydrostratigraphic units at the site. TDEM data defined a three-layer electrical stratigraphy corresponding to a conductor-resistor-conductor that represents the hydrostratigraphic units - the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the Yegua Formation. Sharp electrical boundaries occur at about 4 to 6 and 20 to 22 meters below land surface based on the TDEM data and define the geometry of the more resistive Brazos River alluvium aquifer

  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. Evaluation of some Geophysical and Physicochemical ...

    African Journals Online (AJOL)

    PROF HORSFALL

    2018-04-18

    Apr 18, 2018 ... spill point parallel to the pipeline right of way. A research work carried ... of soils has been known to affect soil physio-chemical properties, which in .... The results of the geophysical analysis from the study area are presented ...

  16. 36 CFR 1256.62 - Geological and geophysical information relating to wells.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical... MATERIALS General Restrictions § 1256.62 Geological and geophysical information relating to wells. (a) In accordance with 5 U.S.C. 552(b)(9), NARA may withhold information in records that relates to geological and...

  17. 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.

  18. Detection and delineation of waste trenches by geophysical methods at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Selfridge, R.J.

    1987-01-01

    Detection and delineation of waste trenches at hazardous waste sites are needed before actual implementation of site corrective measures. In a field study conducted in Solid Waste Storage Area 4 (SWSA4) at Oak Ridge National Laboratory (ORNL), surface geophysical techniques were used to assist in the delineation of waste trenches. A magnetometer/gradiometer survey was used to detect ferrous metals buried at the site. An electromagnetic ground conductivity survey was used to measure the electrical conductivity of the subsurface and aided in supporting the magnetometer/gradiometer results. Results from the two techniques were complimentary and easily integrated into a final interpretation. The reliability, efficiency, and worker safety benefits of these techniques offer a nondestructive surface technique for locating buried waste trenches

  19. 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)

  20. FY 2000 Annual Report for EMSP Project No.70108 - Effects of Fluid Distribution on Measured Geophysical Properties for Partially Saturated, Shallow Subsurface Conditions

    International Nuclear Information System (INIS)

    Berge, P.A.; Bonner, B.P.; Roberts, J.J.; Wildenschild, D.; Aracne-Ruddle, C.M.; Berryman, J.G.; Bertete-Aguirre, H.; Boro, C.O.; Carlberg, E.D.

    2000-01-01

    Our goal is to improve geophysical imaging of the vadose zone. We will achieve this goal by providing new methods to improve interpretation of field data. The purpose of this EMSP project is to develop relationships between laboratory measured geophysical properties and porosity, saturation, and fluid distribution, for partially saturated soils. Algorithms for relationships between soil composition, saturation, and geophysical measurements will provide new methods to interpret geophysical field data collected in the vadose zone at sites such as Hanford, WA. This report summarizes work after 10 months of a 3-year project. We have modified a laboratory ultrasonics apparatus developed in a previous EMSP project (No.55411) so that we can make velocity measurements for partially-saturated samples rather than fully-saturated or dry samples. We are testing the measurement apparatus using standard laboratory sand samples such as Ottawa sand samples. Preliminary results indicate that we can measure both compressional and shear velocities in these sand samples. We have received Hanford soil samples (sands from split-spoon cores from an uncontaminated site) and expect to make ultrasonic measurements on them also. We have used the LLNL x-ray facility to perform x-ray computed tomography (XCT) imaging for several partially-saturated Ottawa sand and Lincoln sand samples, and have also used the DOE Advance Photon Source at Argonne National Laboratory to make higher-resolution images of some sand samples. Preliminary results indicate that we can image amount and distribution of fluids in homogeneous sand samples. Continuing work from the previous EMSP project, we are testing a new data analysis method for seismic data that is expected to improve interpretation of seismic data from the vadose zone by showing how partial saturation affects seismic parameters. Our results suggest that the planned approach for this research is appropriate, that microstructure is an important factor

  1. Karst aquifer characterization using geophysical remote sensing of dynamic recharge events

    Science.gov (United States)

    Grapenthin, R.; Bilek, S. L.; Luhmann, A. J.

    2017-12-01

    Geophysical monitoring techniques, long used to make significant advances in a wide range of deeper Earth science disciplines, are now being employed to track surficial processes such as landslide, glacier, and river flow. Karst aquifers are another important hydrologic resource that can benefit from geophysical remote sensing, as this monitoring allows for safe, noninvasive karst conduit measurements. Conduit networks are typically poorly constrained, let alone the processes that occur within them. Geophysical monitoring can also provide a regionally integrated analysis to characterize subsurface architecture and to understand the dynamics of flow and recharge processes in karst aquifers. Geophysical signals are likely produced by several processes during recharge events in karst aquifers. For example, pressure pulses occur when water enters conduits that are full of water, and experiments suggest seismic signals result from this process. Furthermore, increasing water pressure in conduits during recharge events increases the load applied to conduit walls, which deforms the surrounding rock to yield measureable surface displacements. Measureable deformation should also occur with mass loading, with subsidence and rebound signals associated with increases and decreases of water mass stored in the aquifer, respectively. Additionally, geophysical signals will likely arise with turbulent flow and pore pressure change in the rock surrounding conduits. Here we present seismic data collected during a pilot study of controlled and natural recharge events in a karst aquifer system near Bear Spring, near Eyota, MN, USA as well as preliminary model results regarding the processes described above. In addition, we will discuss an upcoming field campaign where we will use seismometers, tiltmeters, and GPS instruments to monitor for recharge-induced responses in a FL, USA karst system with existing cave maps, coupling these geophysical observations with hydrologic and

  2. Multifractal characterizations of nonstationary and intermittency in geophysical fields: Observed, retrieved, or simulated

    International Nuclear Information System (INIS)

    Davis, A.; Wiscombe, W.; Cahalan, R.; Marshak, A.

    1994-01-01

    Geophysical data rarely show any smoothness at any scale, and this often makes comparison with theoretical model output difficult. However, highly fluctuating signals and fractual structures are typical of open dissipative systems with nonlinear dynamics, the focus of most geophysical research. High levels of variability are excited over a large range of scales by the combined actions of external forcing and internal instability. At very small scales we expect geophysical fields to be smooth, but these are rarely resolved with available instrumentation or simulation tools; nondifferentiable and even discontinuous models are therefore in order. We need methods of statistically analyzing geophysical data, whether measured in situ, remotely sensed or even generated by a computer model, that are adapted to these characteristics. An important preliminary task is to define statistically stationary features in generally nonstationary signals. We first discuss a simple criterion for stationarity in finite data streams that exhibit power law energy spectra and then, guided by developments in turbulence studies, we advocate the use of two ways of analyzing the scale dependence of statistical information: singular measures and qth order structure functions. In nonstationary situations, the approach based on singular measures seeks power law behavior in integrals over all possible scales of a nonnegative stationary field derived from the data, leading to a characterization of the intermittency in this field. In contrast, the approach based on structure functions uses the signal itself, seeking power laws for the statistical moments of absolute increments over arbitrarily large scales, leading to a characterization of the prevailing nonstationarity in both quantitative and qualitative terms. We explain graphically, step by step, both multifractal statistics which are largely complementary to each other. 45 refs., 13 figs., 2 tabs

  3. 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.

  4. Geophysical investigations in the 100 Areas: Fiscal year 1991 through December 1993

    Science.gov (United States)

    Mitchell, T. H.

    1994-09-01

    The geophysical investigations identified in this document were conducted by the Westinghouse Hanford Company (WHC) Surface Geophysics Team, Geophysics Group, between October, 1991 and December, 1993. The investigations supported 100-Area activities for the Resource Conservation and Recovery Act of 1976 (RCRA) and the Comprehensive Environmental Response, Compensations and Liability Act of 1980 (CERCLA). The primary intent of this document is to provide a general map location and the associated document number for investigations that have been conducted as of December, 1993. The results of the individual investigations are not included here. The results of all of these investigations have been previously reported individually in WHC supporting documents. The investigations conducted during Fiscal Year (FY) 1992 are summarized in a single WHC document, WHC-SD-EN-TI-204, Rev. O. A brief summary of some of the successful applications of geophysics in the 100-Areas is included.

  5. Geophysical applications for oil sand mine tailings management

    Energy Technology Data Exchange (ETDEWEB)

    Parker, D.; Bauman, P. [WorleyParsons, Calgary, AB (Canada)

    2009-07-01

    Geophysical techniques are applied throughout a mine's life cycle to facilitate siting, constructing and monitoring of tailings dumps and ponds. This presentation described 3 case studies from the Athabasca region in northeast Alberta that demonstrated some of the concerns associated with oil sand mine tailings, and the information that geophysical surveys can provide. The objectives of these studies were to determine the lateral and depth extents of elevated conductivities of soil and groundwater that have high salt concentration from the tailings sand pore fluid. Due to high chloride concentrations within the tailings material, salt within the root zone may affect vegetation. A terrain conductivity survey was designed to map the lateral extents of salinity impact, while an electrical resistivity tomography (ERT) survey was used to delineate the tailings sand leachate at depth. The proper management of oil sand tailings facilities is vital to the life cycle of a mine. It was concluded that geophysical techniques can be instrumental in managing several engineering and environmental challenges, from Pleistocene channel mapping, to tailings pond settling characteristics, to reclaiming tailings sands. 1 ref., 7 figs.

  6. Visualization of Information Based on Tweets from Meteorological, Climatological, and Geophysical Agency: BMKG

    Directory of Open Access Journals (Sweden)

    Mira Chandra Kirana

    2018-05-01

    Full Text Available Indonesia is a country with high rate of natural disaster, so any information about early warning of natural disaster are very important. Social media such as Twitter become one of tools for spreading information about natural disaster warning from account of  Meteorology, Climatology and Geophysics Agency (BMKG, therefore, the effectiveness of this kind of method for providing information have not known yet. The statement becomes the reason that the visualization is needed to analyze the information spread of natural disaster early warning with Twitter. This study is performed in 3 steps, which is retrieving, preprocessing then visualization. Retrieving process is used to get the tweet data of BMKG account in twitter then save into database, while preprocessing is done to process tweet data that has been saved in database by grouping the data according to the category, which includes Meteorology, Climatology, and Geophysics according to existing keyword, also reduce tweet data that is unimportant like BMKG's reply tweet toward other user's question. Visualization stage uses the result of preprocessing data into line chart graphic, bar chart and pie chart. Highest information spreading from BMKG tweet happened in Geophysics at March with 25987 re-tweets, while the highest peak happened at 2 March 2016 with information about 8.3 SR earthquake in Mentawai islands, West Sumatera with total of 6145 re-tweets.

  7. Geophysical techniques in detection to river embankments - A case study: To locate sites of potential leaks using surface-wave and electrical methods

    Science.gov (United States)

    Chen, C.; Liu, J.; Xu, S.; Xia, J.; ,

    2004-01-01

    Geophysical technologies are very effective in environmental, engineering and groundwater applications. Parameters of delineating nature of near-surface materials such as compressional-wave velocity, shear-wave velocity can be obtained using shallow seismic methods. Electric methods are primary approaches for investigating groundwater and detecting leakage. Both of methods are applied to detect embankment in hope of obtaining evidences of the strength and moisture inside the body. A technological experiment has done for detecting and discovering the hidden troubles in the embankment of Yangtze River, Songzi, Hubei, China in 2003. Surface-wave and DC multi-channel array resistivity sounding techniques were used to detect hidden trouble inside and under dike like pipe-seeps. This paper discusses the exploration strategy and the effect of geological characteristics. A practical approach of combining seismic and electric resistivity measurements was applied to locate potential pipe-seeps in embankment in the experiment. The method presents a potential leak factor based on the shear-wave velocity and the resistivity of the medium to evaluate anomalies. An anomaly found in a segment of embankment detected was verified, where occurred a pipe-seep during the 98' flooding.

  8. Borehole geophysics in nuclear power plant siting

    International Nuclear Information System (INIS)

    Crosby, J.W.; Scott, J.D.

    1979-01-01

    Miniaturized borehole geophysical equipment designed for use in ground-water investigations can be adapted to investigations of nuclear power plant sites. This equipment has proved to be of value in preliminary and comprehensive studies of interior basins where thick sequences of Quaternary clastic sediment, occasionally with associated volcanic rocks, pose problems of stratigraphic correlation. The unconsolidated nature of the deposits generally requires that exploratory holes be cased, which ordinarily restricts the borehole geophysical studies to the radiation functions--natural gamma, gamma-gamma, neutron-gamma, and neutron-epithermal neutron logs. Although a single log response may be dominant in a given area, correlations derive from consideration of all log responses as a composite group. Because major correlations usually are based upon subtle differences in the physical properties of the penetrated sediment, high-resolution logging procedures are employed with some sacrifice of the quantitative parameters important to petroleum technology. All geophysical field data are recorded as hard copy and as digital information on punched paper tape. Digital data are subsequently computer processed and plotted to scales that enhance the stratigraphic data being correlated. Retention of the data in analog format permits rapid review, whereas computer plotting allows playback and detailed examination of log sections and sequences that may be attenuated on hard copy because of the logarithmic nature of the response to the physical property being examined

  9. The identification of faults using morphostructural and geophysical methods: a case study from Strašín Cave site

    Czech Academy of Sciences Publication Activity Database

    Hartvich, Filip; Valenta, Jan

    2011-01-01

    Roč. 8, č. 4 (2011), s. 425-441 ISSN 1214-9705 R&D Projects: GA AV ČR KJB300460803 Institutional research plan: CEZ:AV0Z30460519 Keywords : geophysical profiling * morphostructural analysis * cave Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/abstracts/AGG/04_11/5_Hartvich.pdf

  10. Efficiency Evaluation of Handling of Geologic-Geophysical Information by Means of Computer Systems

    Science.gov (United States)

    Nuriyahmetova, S. M.; Demyanova, O. V.; Zabirova, L. M.; Gataullin, I. I.; Fathutdinova, O. A.; Kaptelinina, E. A.

    2018-05-01

    Development of oil and gas resources, considering difficult geological, geographical and economic conditions, requires considerable finance costs; therefore their careful reasons, application of the most perspective directions and modern technologies from the point of view of cost efficiency of planned activities are necessary. For ensuring high precision of regional and local forecasts and modeling of reservoirs of fields of hydrocarbonic raw materials, it is necessary to analyze huge arrays of the distributed information which is constantly changing spatial. The solution of this task requires application of modern remote methods of a research of the perspective oil-and-gas territories, complex use of materials remote, nondestructive the environment of geologic-geophysical and space methods of sounding of Earth and the most perfect technologies of their handling. In the article, the authors considered experience of handling of geologic-geophysical information by means of computer systems by the Russian and foreign companies. Conclusions that the multidimensional analysis of geologicgeophysical information space, effective planning and monitoring of exploration works requires broad use of geoinformation technologies as one of the most perspective directions in achievement of high profitability of an oil and gas industry are drawn.

  11. Optimized Enhanced Bioremediation Through 4D Geophysical Monitoring and Autonomous Data Collection, Processing and Analysis

    Science.gov (United States)

    2014-09-01

    ER-200717) Optimized Enhanced Bioremediation Through 4D Geophysical Monitoring and Autonomous Data Collection, Processing and Analysis...N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Optimized Enhanced Bioremediation Through 4D Geophysical Monitoring and Autonomous Data...8 2.1.2 The Geophysical Signatures of Bioremediation ......................................... 8 2.2 PRIOR

  12. An Integration of Geophysical Methods to Explore Buried Structures on the Bench and in the Field

    Science.gov (United States)

    Booterbaugh, A. P.; Lachhab, A.

    2011-12-01

    In the following study, an integration of geophysical methods and devices were implemented on the bench and in the field to accurately identify buried structures. Electrical resistivity and ground penetrating radar methods, including both a fabricated electrical resistivity apparatus and an electrical resistivity device were all used in this study. The primary goal of the study was to test the accuracy and reliability of the apparatus which costs a fraction of the price of a commercially sold resistivity instrument. The apparatus consists of four electrodes, two multimeters, a 12-volt battery, a DC to AC inverter and wires. Using this apparatus, an electrical current, is injected into earth material through the outer electrodes and the potential voltage is measured across the inner electrodes using a multimeter. The recorded potential and the intensity of the current can then be used to calculate the apparent resistivity of a given material. In this study the Wenner array, which consists of four equally spaced electrodes, was used due to its higher accuracy and greater resolution when investigating lateral variations of resistivity in shallow depths. In addition, the apparatus was used with an electrical resistivity device and a ground penetrating radar unit to explore the buried building foundation of Gustavus Adolphus Hall located on Susquehanna University Campus, Selinsgrove, PA. The apparatus successfully produced consistent results on the bench level revealing the location of small bricks buried under a soil material. In the summer of 2010, seventeen electrical resistivity transects were conducted on the Gustavus Adolphus site where and revealed remnants of the foundation. In the summer of 2011, a ground penetrating radar survey and an electrical resistivity tomography survey were conducted to further explore the site. Together these methods identified the location of the foundation and proved that the apparatus was a reliable tool for regular use on the bench

  13. Investigation of Methane and Soil Carbon Dynamics Using Near Surface Geophysical Methods at the Tanoma Educational Wetland Site, Tanoma, Pennsylvania

    Science.gov (United States)

    Seidel, A. D.; Mount, G.

    2017-12-01

    Studies to constrain methane budgets of Pennsylvania have sought to quantify the amount and rate of fugitive methane released during industrial natural gas development. However, contributions from other environmental systems such as artificial wetlands used to treat part of the 300 million gallons per day of acid mine drainage (AMD) are often not understated or not considered. The artificial wetlands are sources of both biogenic and thermogenic methane and are used to treat AMD which would otherwise flow untreated into Pennsylvania surface waters. Our research utilizes a combination of indirect non-invasive geophysical methods (ground penetrating radar, GPR) and the complex refractive index model, aerial imagery, and direct measurements (coring and gas traps) to estimate the contribution of biogenic methane from wetlands and legacy thermogenic methane from acid mine drainage from a flooded coal mine at an artificial wetland designed to treat these polluted waters at Tanoma, Pennsylvania. Our approach uses (3D) GPR surveys to define the thickness of the soil from the surface to the regolith-bedrock interface to create a volume model of potential biogenic gas stores. Velocity data derived from the GPR is then used to calculate the dielectric permittivity of the soil and then modeled for gas content when considering the saturation, porosity and amount of soil present. Depth-profile cores are extracted to confirm soil column interfaces and determine changes in soil carbon content. Comparisons of gas content are made with gas traps placed across the wetlands that measure the variability of gaseous methane released. In addition, methane dissolved in the waters from biogenic processes in the wetland and thermogenic processes underground are analyzed by a gas chromatograph to quantify those additions. In sum, these values can then be extrapolated to estimate carbon stocks in AMD areas such as those with similar water quality and vegetation types in the Appalachian region

  14. Development of nuclear physics and its connections to borehole geophysics

    International Nuclear Information System (INIS)

    Loetzsch, W.

    1990-01-01

    Starting from the discovery of radioactivity, the development of nuclear physics and its close connections to geoscience, especially to borehole geophysics, are outlined. The discovery of a nuclear physical phenomenon is always followed by an examination for its applications in nuclear geophysics, which since about 1960 has developed into a special discipline of applied geophysics. As an example for this development in the GDR the application of neutron capture γ-ray spectroscopy for iron ore exploration is described. A table listing important present-day nuclear well logging techniques with detectable elements and their detection limits is presented. Examples of measurements with some of these logging techniques reveal their particularities and show their element-specific character and the nuclear physical mechanisms involved. Finally the state of art of nuclear well logging and prospects in this field are outlined. (author)

  15. Evaluation of ground stiffness parameters using continuous surface wave geophysics

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    Present day knowledge of the magnitude of the strain levels in the ground associated with geotechnical structures, together with an increasing number of projects requiring the best estimates of ground movements around excavations, has led to, inter alia, increased interest in measuring the very......-small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  16. 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

  17. Geophysical Investigation of a Thermokarst Lake Talik in Continuous Permafrost

    Science.gov (United States)

    Creighton, A.; Parsekian, A.; Arp, C. D.; Jones, B. M.; Babcock, E.; Bondurant, A. C.

    2016-12-01

    On the Arctic Coastal Plain (ACP) of northern Alaska, shallow thermokarst lakes cover up to 25% of the landscape. These lakes occupy depressions created by the subsidence of thawed, ice-rich permafrost. Areas of unfrozen sediment, or taliks, can form under lakes that have a mean annual bottom temperature greater than 0°C. The geometry of these taliks, as well as the processes that create them, are important for understanding interactions between surface water, groundwater, and carbon cycling. Non-invasive geophysical methods are a useful means to study talik sediments as borehole studies yield few data points, and the contrast between unfrozen and frozen sediments is an ideal geophysical target. To study talik configuration associated with an actively expanding thermokarst lake, we conducted a geophysical transect across Peatball Lake. This lake has an estimated initiation age of 1400 calendar years BP. Over the past 60 years, lake surface area has increased through thermal and mechanical shoreline erosion. A talik of previously unknown thickness likely exists below Peatball Lake. We conducted a transect of transient electromagnetic soundings across the lake extending into the surrounding terrestrial environment. Since permafrost has relatively high resistivity compared to talik sediments, the interpreted electrical structure of the subsurface likely reflects talik geometry. We also conducted nuclear magnetic resonance soundings at representative locations along the transect. These measurements can provide data on sub-lake sediment properties including water content. Together, these measurements resolve the talik structure across the lake transect and showed evidence of varying talik thicknesses from the lake edge to center. These is no evidence of a talik at the terrestrial control sites. These results can help constrain talik development models and thus provide insight into Arctic and permafrost processes in the face of a changing climate.

  18. 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...

  19. The role of the geophysical template and environmental regimes in controlling stream-living trout populations

    Science.gov (United States)

    Penaluna, Brooke E.; Railsback, Steve F.; Dunham, Jason B.; Johnson, S.; Bilby, Richard E.; Skaugset, Arne E.

    2015-01-01

    The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams.

  20. Escript: Open Source Environment For Solving Large-Scale Geophysical Joint Inversion Problems in Python

    Science.gov (United States)

    Gross, Lutz; Altinay, Cihan; Fenwick, Joel; Smith, Troy

    2014-05-01

    The program package escript has been designed for solving mathematical modeling problems using python, see Gross et al. (2013). Its development and maintenance has been funded by the Australian Commonwealth to provide open source software infrastructure for the Australian Earth Science community (recent funding by the Australian Geophysical Observing System EIF (AGOS) and the AuScope Collaborative Research Infrastructure Scheme (CRIS)). The key concepts of escript are based on the terminology of spatial functions and partial differential equations (PDEs) - an approach providing abstraction from the underlying spatial discretization method (i.e. the finite element method (FEM)). This feature presents a programming environment to the user which is easy to use even for complex models. Due to the fact that implementations are independent from data structures simulations are easily portable across desktop computers and scalable compute clusters without modifications to the program code. escript has been successfully applied in a variety of applications including modeling mantel convection, melting processes, volcanic flow, earthquakes, faulting, multi-phase flow, block caving and mineralization (see Poulet et al. 2013). The recent escript release (see Gross et al. (2013)) provides an open framework for solving joint inversion problems for geophysical data sets (potential field, seismic and electro-magnetic). The strategy bases on the idea to formulate the inversion problem as an optimization problem with PDE constraints where the cost function is defined by the data defect and the regularization term for the rock properties, see Gross & Kemp (2013). This approach of first-optimize-then-discretize avoids the assemblage of the - in general- dense sensitivity matrix as used in conventional approaches where discrete programming techniques are applied to the discretized problem (first-discretize-then-optimize). In this paper we will discuss the mathematical framework for

  1. The assessment of the geophysical investigations of boreholes

    International Nuclear Information System (INIS)

    Brotzen, O.; Duran, O.; Magnusson, K.-Aa.

    1980-02-01

    Four geophysical investigations and a televiewer inspection of boreholes have been evaluated in connection with the examinations at Finnsjoen, Karlshamn, Kraakemaala, Stripa and Studsvik. A cooperative assessment of the systems for the measurement of boreholes by Lawrence Berkeley Laboratories and the Geological Survey of Sweden has been made at Stripa. The following methods should be selected for future measurements: determination of the resistivity and temperature of the fluid in the borehole, determination of the resistivity and temperature of the fluid in the borehole, determination of the self-potential, resistivity and resistance of the rock as well as the measurement of sonar waves, the diameter of the borehole and the very low frequency effects. (G.B.)

  2. Integration of potential and quasipotential geophysical fields and GPR data for delineation of buried karst terranes in complex environments

    Science.gov (United States)

    Eppelbaum, L. V.; Alperovich, L. S.; Zheludev, V.; Ezersky, M.; Al-Zoubi, A.; Levi, E.

    2012-04-01

    Karst is found on particularly soluble rocks, especially limestone, marble, and dolomite (carbonate rocks), but is also developed on gypsum and rock salt. Subsurface carbonate rocks involved in karst groundwater circulation considerably extend the active karst realm, to perhaps 14% of the world's land area (Price, 2009). The phenomenon of the solution weathering of limestone is the most widely known in the world. Active sinkholes growth appears under different industrial constructions, roads, railways, bridges, airports, buildings, etc. Regions with arid and semi-arid climate occupy about 30% of the Earth's land. Subsurface in arid regions is characterized by high variability of physical properties both on lateral and vertical that complicates geophysical survey analysis. Therefore for localization and monitoring of karst terranes effective and reliable geophysical methodologies should be applied. Such advanced methods were developed in microgravity (Eppelbaum et al., 2008; Eppelbaum, 2011b), magnetic (Khesin et al., 1996; Eppelbaum et al., 2000, 2004; Eppelbaum, 2011a), induced polarization (Khesin et al., 1997; Eppelbaum and Khesin, 2002), VLF (Eppelbaum and Khesin, 1992; Eppelbaum and Mishne, 2012), near-surface temperature (Eppelbaum, 2009), self-potential (Khesin et al., 1996; Eppelbaum and Khesin, 2002), and resistivity (Eppelbaum, 1999, 2007a) surveys. Application of some of these methodologies in the western and eastern shores of the Dead Sea area (e.g., Eppelbaum et al., 2008; Ezersky et al., 2010; Al-Zoubi et al., 2011) and in other regions of the world (Eppelbaum, 2007a) has shown their effectiveness. The common procedures for ring structure identification against the noise background and probabilistic-deterministic methods for recognizing the desired targets in complex media are presented in Khesin and Eppelbaum (1997), Eppelbaum et al. (2003), and Eppelbaum (2007b). For integrated analysis of different geophysical fields (including GPR images) intended

  3. 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

  4. Geophysics Based Contaminant Mass Discharge Quantification Downgradient of a Landfill and a Former Pharmaceutical Factory

    DEFF Research Database (Denmark)

    Balbarini, Nicola; Rønde, Vinni Kampman; Maurya, Pradip

    2018-01-01

    Contaminant mass discharge is a commonly applied tool to evaluate the environmental impact of contaminated sites on water resources. At large contaminated sites with heterogeneous sources, such as landfills, the number of wells available is often not sufficient, leading to a high uncertainty...... of mass discharge estimates. In this study, we tackle the uncertainty of the contaminant mass discharge due to low sampling densities by interpolating limited water‐sample data with the support of surface Direct Current resistivity and Induced Polarization geophysical data. The method relies on finding...... a conceptual link between the bulk conductivity imaged from geophysics and the contaminant concentrations. We investigate the link between: 1) imaged bulk and electrical water conductivity, 2) water conductivity and conservative ionic species, 3) water conductivity and redox‐sensitive species, 4) water...

  5. rights reserved Geophysical Identification of Hydrothermally Altered

    African Journals Online (AJOL)

    ADOWIE PERE

    Geophysical Identification of Hydrothermally Altered Structures That Favour .... aircraft. Total line kilometers of 36,500 were covered in the survey. Magnetic ... tie lines occur at about 2000 metres interval in the ... visual inspection of the map.

  6. Smartphones - the Geophysics Lab in Your Students' Pocket

    Science.gov (United States)

    Salaree, A.; Stein, S.; Saloor, N.; Elling, R. P.

    2017-12-01

    Many interesting topics are hard to demonstrate in geophysics classes without costly equipment and logistic hassles. For instance, the speed of P-waves in the Earth's crust is usually calculated using printed seismic sections from published studies, giving students little insight into the recording process. This is mainly due to the complex, costly, and weather-dependent logistics of conducting seismic reflection experiments using arrays of - either purchased or borrowed - expensive seismometers and recording units. Smartphones, which students own and are (perhaps unduly) comfortable with, have many otherwise expensive instruments as built-in sensors. These instruments are nifty tools that make labs easier, faster, and more fun. We use smartphones in several labs in an introductory geophysics class. In one, students use their phones to measure the latitude and longitude of a point on campus. Combining the data shows a nice spread of positions illustrating the precision of measurements, spatial trends in the scatter, and even differences between Android and iPhone data. Hence concepts about data that are often presented with ideal theoretical examples emerge from the students' measurements. Another uses the phones' accelerometers and available software to measure the speed of P-waves using a linear array of smartphones/seismometers along a table, similar to the procedure used in reflection seismology. In a third, students used their smartphones in an elevator to measure the acceleration of gravity in a moving reference frame, and thus explore key concepts that arise in many geophysical applications. These three applications illustrate the potential for using smartphones in a wide variety of geophysics teaching, much as their value is being increasingly recognized in other educational applications. Here are some links to an instructions document and a video from the seismic experiment: Instructions: http://www.earth.northwestern.edu/ amir/202/smartphone

  7. 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

  8. 76 FR 68720 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Science.gov (United States)

    2011-11-07

    ... Marine Mammals Incidental to Specified Activities; Low- Energy Marine Geophysical Survey in the Western... conducting a low-energy marine geophysical (i.e., seismic) survey in the western tropical Pacific Ocean... Science Foundation (NSF), and ``Environmental Assessment of a Low-Energy Marine Geophysical Survey by the...

  9. Geophysical analysis for the Ada Tepe region (Bulgaria) - case study

    Science.gov (United States)

    Trifonova, Petya; Metodiev, Metodi; Solakov, Dimcho; Simeonova, Stela; Vatseva, Rumiana

    2013-04-01

    According to the current archeological investigations Ada Tepe is the oldest gold mine in Europe with Late Bronze and Early Iron age. It is a typical low-sulfidation epithermal gold deposit and is hosted in Maastrichtian-Paleocene sedimentary rocks above a detachment fault contact with underlying Paleozoic metamorphic rocks. Ada Tepe (25o.39'E; 41o.25'N) is located in the Eastern Rhodope unit. The region is highly segmented despite the low altitude (470-750 m) due to widespread volcanic and sediment rocks susceptible to torrential erosion during the cold season. Besides the thorough geological exploration focused on identifying cost-effective stocks of mineral resources, a detailed geophysical analysis concernig diferent stages of the gold extraction project was accomplished. We present the main results from the geophysical investigation aimed to clarify the complex seismotectonic setting of the Ada Tepe site region. The overall study methodology consists of collecting, reviewing and estimating geophysical and seismological information to constrain the model used for seismic hazard assessment of the area. Geophysical information used in the present work consists of gravity, geomagnetic and seismological data. Interpretation of gravity data is applied to outline the axes of steep gravity transitions marked as potential axes of faults, flexures and other structures of dislocation. Direct inverse techniques are also utilized to estimate the form and depth of anomalous sources. For the purposes of seismological investigation of the Ada Tepe site region an earthquake catalogue is compiled for the time period 510BC - 2011AD. Statistical parameters of seismicity - annual seismic rate parameter, ?, and the b-value of the Gutenberg-Richter exponential relation for Ada Tepe site region, are estimated. All geophysical datasets and derived results are integrated using GIS techniques ensuring interoperability of data when combining, processing and visualizing obtained

  10. 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

  11. Results of integrated geophysical measurements on a landslide endangered brown coal dump

    Energy Technology Data Exchange (ETDEWEB)

    Militzer, H; Lindner, H; Kaeppler, R

    1984-01-01

    The measurements revealed occurrence of geophysical anomalies across artificial soils with low content of cohesive material. The proven anomalies varied with time with regard to their magnitude and position. Possible relations between the temporal variations of the geophysical fields and a landslide on the boundary of the object are discussed.

  12. Foundation integrity assessment using integrated geophysical and geotechnical techniques: case study in crystalline basement complex, southwestern Nigeria

    Science.gov (United States)

    Olayanju, G. M.; Mogaji, K. A.; Lim, H. S.; Ojo, T. S.

    2017-06-01

    The determination of parameters comprising exact depth to bedrock and its lithological type, lateral changes in lithology, and detection of fractures, cracks, or faults are essential to designing formidable foundations and assessing the integrity of civil engineering structures. In this study, soil and site characterization in a typical hard rock geologic terrain in southwestern Nigeria were carried out employing integrated geophysical and geotechnical techniques to address tragedies in civil engineering infrastructural development. The deployed geophysical measurements involved running both very low frequency electromagnetic (VLF-EM) and electrical resistivity methods (dipole-dipole imaging and vertical electrical sounding (VES) techniques) along the established traverses, while the latter technique entailed conducting geological laboratory sieve analysis and Atterberg limit-index tests upon the collected soil samples in the area. The results of the geophysical measurement, based on the interpreted VLF-EM and dipole-dipole data, revealed conductive zones and linear features interpreted as fractures/faults which endanger the foundations of public infrastructures. The delineation of four distinct geoelectric layers in the area—comprised of topsoil, lateritic/clayey substratum, weathered layer, and bedrock—were based on the VES results. Strong evidence, including high degree of decomposition and fracturing of underlying bedrock revealed by the VES results, confirmed the VLF-EM and dipole-dipole results. Furthermore, values in the range of 74.2%-77.8%, 55%-62.5%, 23.4%-24.5%, 7.7%-8.2%, 19.5%-22.4%, and 31.65%-38.25% were obtained for these geotechnical parameters viz soil percentage passing 0.075 mm sieve size, liquid limit, plasticity index, linear shrinkage, natural moisture content, and plastic limit, respectively, resulting from the geotechnical analysis of the soil samples. The comparatively analyzed geophysical and geotechnical results revealed a high

  13. Solid state nuclear track detection: a useful geological/geophysical tool

    International Nuclear Information System (INIS)

    Khan, H.A.; Qureshi, A.A.

    1994-01-01

    Solid State Nuclear Track Detection (SSNTD) is a relatively new nuclear particle detection technique. Since its inception, it has found useful application in almost every branch of science. This paper gives a very brief review of the role it has played in solving some geological/geophysical problems. Since the technique has been found useful in a wide spectrum of geological/geophysical applications, it was simply not possible to discuss all of these in this paper due to severe space restrictions. However, an attempt has been made to discuss the salient features of some of the most prominent applications in the geological and geophysical sciences. The paper has been divided into two parts. Firstly, applications based on radon measurements by SSNTDs have been described. These include: Uranium/thorium and mineral exploration, search for geothermal energy sources, study of volcanic processes, location of geological faults and earthquake prediction, for example. Secondly, applications based on the study of spontaneous fission tracks in geological samples have been described briefly. The second group of applications includes: fission track dating (FTD) of geological samples, FTD in the study of emplacement times, provenance studies, and thermal histories of minerals. Necessary references have been provided for detailed studies of (a) the applications cited in this paper, and (b) other important geological/geophysical applications, which unfortunately could not be covered in the present paper. (author)

  14. 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...

  15. Review of Electrical and Gravity Methods of Near-Surface ...

    African Journals Online (AJOL)

    USER

    ABSTRACT: The theory and practice of electrical and gravity methods of geophysics for groundwater exploration was reviewed with illustrations and data examples. With the goal of reducing cases of borehole/water-well failure attributed to the lack of the knowledge of the methods of geophysics for groundwater exploration ...

  16. An integrated geophysical and hydraulic investigation to characterize a fractured-rock aquifer, Norwalk, Connecticut

    Science.gov (United States)

    Lane, J.W.; Williams, J.H.; Johnson, C.D.; Savino, D.M.; Haeni, F.P.

    2002-01-01

    The U.S. Geological Survey conducted an integrated geophysical and hydraulic investigation at the Norden Systems, Inc. site in Norwalk, Connecticut, where chlorinated solvents have contaminated a fractured-rock aquifer. Borehole, borehole-to-borehole, surface-geophysical, and hydraulic methods were used to characterize the site bedrock lithology and structure, fractures, and transmissive zone hydraulic properties. The geophysical and hydraulic methods included conventional logs, borehole imagery, borehole radar, flowmeter under ambient and stressed hydraulic conditions, and azimuthal square-array direct-current resistivity soundings. Integrated interpretation of geophysical logs at borehole and borehole-to-borehole scales indicates that the bedrock foliation strikes northwest and dips northeast, and strikes north-northeast to northeast and dips both southeast and northwest. Although steeply dipping fractures that cross-cut foliation are observed, most fractures are parallel or sub-parallel to foliation. Steeply dipping reflectors observed in the radar reflection data from three boreholes near the main building delineate a north-northeast trending feature interpreted as a fracture zone. Results of radar tomography conducted close to a suspected contaminant source area indicate that a zone of low electromagnetic (EM) velocity and high EM attenuation is present above 50 ft in depth - the region containing the highest density of fractures. Flowmeter logging was used to estimate hydraulic properties in the boreholes. Thirty-three transmissive fracture zones were identified in 11 of the boreholes. The vertical separation between transmissive zones typically is 10 to 20 ft. Open-hole and discrete-zone transmissivity was estimated from heat-pulse flowmeter data acquired under ambient and stressed conditions. The open-hole transmissivity ranges from 2 to 86 ft2/d. The estimated transmissivity of individual transmissive zones ranges from 0.4 to 68 ft2/d. Drawdown monitoring

  17. 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

  18. Non-invasive Geophysical Surveys in Search of the Roman Temple of Augustus Under the Cathedral of Tarragona (Catalonia, Spain): A Case Study

    Science.gov (United States)

    Casas, Albert; Cosentino, Pietro L.; Fiandaca, Gianluca; Himi, Mahjoub; Macias, Josep M.; Martorana, Raffaele; Muñoz, Andreu; Rivero, Lluís; Sala, Roger; Teixell, Imma

    2018-04-01

    An integrated geophysical survey has been conducted at the Tarragona's Cathedral (Catalonia, NE Spain) with the aim to confirm the potential occurrence of archaeological remains of the Roman Temple dedicated to the Emperor Augustus. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most renowned temples of Spain (twelfth century) evolving from Romanesque to Gothic styles. A geophysical project including electrical resistivity tomography (ERT) and ground probing radar (GPR) was planned over 1 year considering the administrative and logistic difficulties of such a project inside a cathedral of religious veneration. Finally, both ERT and GPR have been conducted during a week of intensive overnight surveys that provided detailed information on subsurface existing structures. The ERT method has been applied using different techniques and arrays, ranging from standard Wenner-Schlumberger 2D sections to full 3D electrical imaging with the advanced Maximum Yield Grid array. Electrical resistivity data were recorded extensively, making available many thousands of apparent resistivity data to obtain a complete 3D image after a full inversion. In conclusion, some significant buried structures have been revealed providing conclusive information for archaeologists. GPR results provided additional information about shallowest structures. The geophysical results were clear enough to persuade religious authorities and archaeologists to conduct selected excavations in the most promising areas that confirmed the interpretation of geophysical data. In conclusion, the significant buried structures revealed by geophysical methods under the cathedral were confirmed by archaeological digging as the basement of the impressive Roman Temple that headed the Provincial Forum of Tarraco, seat of the Concilium of Hispania Citerior Province.

  19. Environmental geophysics: Locating and evaluating subsurface geology, geologic hazards, groundwater contamination, etc

    International Nuclear Information System (INIS)

    Benson, A.K.

    1994-01-01

    Geophysical surveys can be used to help delineate and map subsurface geology, including potential geologic hazards, the water table, boundaries of contaminated plumes, etc. The depth to the water table can be determined using seismic and ground penetrating radar (GPR) methods, and hydrogeologic and geologic cross sections of shallow alluvial aquifers can be constructed from these data. Electrical resistivity and GPR data are especially sensitive to the quality of the water and other fluids in a porous medium, and these surveys help to identify the stratigraphy, the approximate boundaries of contaminant plumes, and the source and amount of contamination in the plumes. Seismic, GPR, electromagnetic (VLF), gravity, and magnetic data help identify and delineate shallow, concealed faulting, cavities, and other subsurface hazards. Integration of these geophysical data sets can help pinpoint sources of subsurface contamination, identify potential geological hazards, and optimize the location of borings, monitoring wells, foundations for building, dams, etc. Case studies from a variety of locations will illustrate these points. 20 refs., 17 figs., 6 tabs

  20. Delineation of Oil – Polluted Sites in Ibeno LGA, Nigeria, Using Geophysical Techniques

    OpenAIRE

    Ime R. Udotong; Justina I. R. Udotong; Ofonime U. M. John

    2015-01-01

    Ibeno, Nigeria hosts the operational base of Mobil Producing Nigeria Unlimited (MPNU), a subsidiary of ExxonMobil and the current highest oil & condensate producer in Nigeria. Besides MPNU, other oil companies operate onshore, on the continental shelf and deep offshore of the Atlantic Ocean in Ibeno, Nigeria. This study was designed to delineate oil polluted sites in Ibeno, Nigeria using geophysical methods of electrical resistivity (ER) and ground penetrating radar (GPR)...

  1. The relationship of fractals in geophysics to 'the new science'

    International Nuclear Information System (INIS)

    Turcotte, Donald L.

    2004-01-01

    Many phenomena in geophysics satisfy fractal statistics, examples range from the frequency-area statistics of earthquakes to the time series of the earth's magnetic field. Solutions to classical differential equations cannot give this type of behavior. Several 'cellular automata' models have successfully reproduced the observed statistics. For example, the slider-block model for earthquakes. Stephen Wolfram's recent book A New Kind of Science sets forth a 'new science' based on cellular automata. This paper discusses the role of cellular automata in geophysics

  2. 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

  3. Geophysical exploration of the Boku geothermal area, Central Ethiopian Rift

    Energy Technology Data Exchange (ETDEWEB)

    Abiye, Tamiru A. [School of Geosciences, Faculty of Science, University of the Witwatersrand, Private Bag X3, P.O. Box Wits, 2050 Johannesburg (South Africa); Tigistu Haile [Department of Geology and Geophysics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)

    2008-12-15

    The Boku central volcano is located within the axial zone of the Central Ethiopian Rift near the town of Nazareth, Ethiopia. An integrated geophysical survey involving thermal, magnetic, electrical and gravimetric methods has been carried out over the Boku geothermal area in order to understand the circulation of fluids in the subsurface, and to localize the 'hot spot' providing heat to the downward migrating groundwaters before they return to the surface. The aim of the investigations was to reconstruct the geometry of the aquifers and the fluid flow paths in the Boku geothermal system, the country's least studied. Geological studies show that it taps heat from the shallow acidic Quaternary volcanic rocks of the Rift floor. The aquifer system is hosted in Quaternary Rift floor ignimbrites that are intensively fractured and receive regional meteoric water recharge from the adjacent escarpment and locally from precipitation and the Awash River. Geophysical surveys have mapped Quaternary faults that are the major geologic structures that allow the ascent of the hotter fluids towards the surface, as well as the cold-water recharge of the geothermal system. The shallow aquifers are mapped, preferred borehole sites for the extraction of thermal fluids are delineated and the depths to deeper thermal aquifers are estimated. (author)

  4. Geophysical survey of two rural sites in Mallorca (Balearic Islands, Spain): Unveiling Roman villae

    Science.gov (United States)

    Mas Florit, Catalina; Cau Ontiveros, Miguel Ángel; Goossens, Lise; Meyer, Cornelius; Sala, Roger; Ortiz, Helena

    2018-03-01

    Two rural sites on the island of Mallorca (Balearic Islands, Spain) have been investigated with geophysical methods. A previous archaeological field survey provided surface ceramics that allowed for a first classification of the sites as possible Roman rural settlements, possibly villae. The objective of the investigation was to work towards the identification of architectural remains to better understand the true nature of the sites. Using the 7-probe fluxgate gradiometer array LEA MAX, magnetic measurements were executed on a large area on each site. GPR measurements were subsequently carried out to examine selected areas of interest in detail by means of the IDS GPR system based on the Fast-Wave module. The investigated areas demonstrated excellent surface conditions with a negligible number of sources of disturbance, permitting a detailed interpretation of the geophysical data. The results helped to reveal the presence of architectural remains beneath the soil at both sites.

  5. 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.

  6. An appraisal of the geologic structure beneath the Ikogosi warm spring in south-western Nigeria using integrated surface geophysical methods

    Directory of Open Access Journals (Sweden)

    J.S Ojo

    2011-06-01

    Full Text Available An integrated surface geophysical investigation involving resistivity and magnetic methods was carried out in the immediate vicinity of the Ikogosi warm spring situated in south-western Nigeria with a view to delineating its subsurface geological sequence and evaluating the structural setting beneath the warmspring. Total field magnetic measurements and vertical electrical sounding (VES data were acquired along five N-S traverses. Magnetic and VES data interpretation
    involved inverse modelling. The inverse magnetic models delineated fractured quartzite/faulted areas within fresh massive quartzite at varying depths and beneath all traverses. The geoelectrical sections developed from VESinterpretation results also delineated a subsurface sequence consisting of a topsoil/weathered layer, fresh quartzite, fractured/faulted quartzite and fresh quartzite bedrock. It was deduced that the fractured/faulted quartzite may have acted as conduit for the
    movement of warm groundwater from profound depths to the surface while the spring outlet was located on a geological interface  (lineament.

  7. 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

  8. Use of Geophysical and Remote Sensing Techniques During the Comprehensive Test Ban Treaty Organization's Integrated Field Exercise 2014

    Science.gov (United States)

    Labak, Peter; Sussman, Aviva; Rowlands, Aled; Chiappini, Massimo; Malich, Gregor; MacLeod, Gordon; Sankey, Peter; Sweeney, Jerry; Tuckwell, George

    2016-04-01

    The Integrated Field Exercise of 2014 (IFE14) was a field event held in the Hashemite Kingdom of Jordan (with concurrent activities in Austria) that tested the operational and technical capabilities of a Comprehensive Test Ban Treaty's (CTBT) on-site inspection (OSI). During an OSI, up to 40 inspectors search a 1000km2 inspection area for evidence of a nuclear explosion. Over 250 experts from ~50 countries were involved in IFE14 (the largest simulation of an OSI to date) and worked from a number of different directions, such as the Exercise Management and Control Teams to execute the scenario in which the exercise was played, to those participants performing as members of the Inspection Team (IT). One of the main objectives of IFE14 was to test Treaty allowed inspection techniques, including a number of geophysical and remote sensing methods. In order to develop a scenario in which the simulated exercise could be carried out, a number of physical features in the IFE14 inspection area were designed and engineered by the Scenario Task Force Group (STF) that the IT could detect by applying the geophysical and remote sensing inspection technologies, as well as other techniques allowed by the CTBT. For example, in preparation for IFE14, the STF modeled a seismic triggering event that was provided to the IT to prompt them to detect and localize aftershocks in the vicinity of a possible explosion. Similarly, the STF planted shallow targets such as borehole casings and pipes for detection by other geophysical methods. In addition, airborne technologies, which included multi-spectral imaging, were deployed such that the IT could identify freshly exposed surfaces, imported materials and other areas that had been subject to modification. This presentation will introduce the CTBT and OSI, explain the IFE14 in terms of goals specific to geophysical and remote sensing methods, and show how both the preparation for and execution of IFE14 meet those goals.

  9. 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

  10. Streamlined Archaeo-geophysical Data Processing and Integration for DoD Field Use

    Science.gov (United States)

    2012-04-01

    6 Figure 2-3. Flowchart illustrating the old, ad-hoc approach of processing...Figure 2-3. Flowchart illustrating the old, ad-hoc approach of processing and integrating multiple geophysical datasets. Each color represents a... beginner , intermediate, and expert user. Most users agreed that the software is very effective for beginners because: (1) it provides a geophysics

  11. Geophysical investigation programme of Northern Switzerland: Gravimetric measurements 81/82

    International Nuclear Information System (INIS)

    Klingele, E.; Schwendener, H.

    1984-10-01

    Within the frame of the geophysical investigations of the NAGRA in the northern part of Switzerland the Swiss Geophysical Commission has measured 4954 gravity stations. The gravity data were processed and presented as Bouguer-anomaly and residual anomaly maps. The densities used for the corrections were 2.40 and 2.67 g/cm 3 . The residual field showed a negative anomaly along an axis passing through Weiach and Villigen. This anomaly can be interpreted quantitatively in terms of depth of the crystalline basement. (author)

  12. An electric and electromagnetic geophysical approach for subsurface investigation of anthropogenic mounds in an urban environment

    Science.gov (United States)

    Pazzi, Veronica; Tapete, Deodato; Cappuccini, Luca; Fanti, Riccardo

    2016-11-01

    Scientific interest in mounds as geomorphological features that currently represent topographic anomalies in flat urban landscapes mainly lies on the understanding of their origin, either purely natural or anthropogenic. In this second circumstance, another question is whether traces of lost buildings are preserved within the mound subsurface and can be mapped as remnants testifying past settlement. When these landforms have been modified in centuries for civilian use, structural stability is a further element of concern. To address these issues we applied a geophysical approach based on a very low frequency electromagnetic (VLF-EM) technique and two-dimensional electrical resistivity tomography (2D-ERT) and integrated it with well-established surface survey methods within a diagnostic workflow of structural assessment. We demonstrate the practical benefits of this method in the English Cemetery of Florence, Italy, whose mixed nature and history of morphological changes are suggested by archival records. The combination of the two selected geophysical techniques allowed us to overcome the physical obstacles caused by tomb density and to prevent interference from the urban vehicular traffic on the geophysical signals. Eighty-two VLF-EM profiles and five 2D-ERTs were collected to maximise the spatial coverage of the subsurface prospection, while surface indicators of instability (e.g., tomb tilt, location, and direction of ground fractures and wall cracks) were mapped by standard metric survey. High resistive anomalies (> 300 and 400 Ωm) observed in VLF-EM tomographies are attributed to remnants of the ancient perimeter wall that are still buried along the southern side of the mound. While no apparent correlation is found between the causes of tomb and ground movements, the crack pattern map supplements the overall structural assessment. The main outcome is that the northern portion of the retaining wall is classed with the highest hazard rate. The impact of this

  13. Geophysical data fusion for subsurface imaging. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This report contains the results of a three year, three-phase project whose long-range goal has been to create a means for the more detailed and accurate definition of the near-surface (0--300 ft) geology beneath a site that had been subjected to environmental pollution. The two major areas of research and development have been: improved geophysical field data acquisition techniques; and analytical tools for providing the total integration (fusion) of all site data. The long-range goal of this project has been to mathematically, integrate the geophysical data that could be derived from multiple sensors with site geologic information and any other type of available site data, to provide a detailed characterization of thin clay layers and geological discontinuities at hazardous waste sites.

  14. Geophysical data fusion for subsurface imaging. Final report

    International Nuclear Information System (INIS)

    1995-10-01

    This report contains the results of a three year, three-phase project whose long-range goal has been to create a means for the more detailed and accurate definition of the near-surface (0--300 ft) geology beneath a site that had been subjected to environmental pollution. The two major areas of research and development have been: improved geophysical field data acquisition techniques; and analytical tools for providing the total integration (fusion) of all site data. The long-range goal of this project has been to mathematically, integrate the geophysical data that could be derived from multiple sensors with site geologic information and any other type of available site data, to provide a detailed characterization of thin clay layers and geological discontinuities at hazardous waste sites

  15. Development and implementation of the software for visualization and analysis of data geophysical loggers

    Science.gov (United States)

    Gordeev, V. F.; Malyshkov, S. Yu.; Botygin, I. A.; Sherstnev, V. S.; Sherstneva, A. I.

    2017-11-01

    The general trend of modern ecological geophysics is changing priorities towards rapid assessment, management and prediction of ecological and engineering soil stability as well as developing brand new geophysical technologies. The article describes researches conducted by using multi-canal geophysical logger MGR-01 (developed by IMCES SB RAS), which allows to measure flux density of very low-frequency electromagnetic radiation. It is shown that natural pulsed electromagnetic fields of the earthen lithosphere can be a source of new information on Earth's crust and processes in it, including earthquakes. The device is intended for logging electromagnetic processes in Earth's crust, geophysical exploration, finding structural and lithological inhomogeneities, monitoring the geodynamic movement of Earth's crust, express assessment of seismic hazards. The data is gathered automatically from observation point network in Siberia

  16. 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

  17. Automated Leak Detection Of Buried Tanks Using Geophysical Methods At The Hanford Nuclear Site

    International Nuclear Information System (INIS)

    Calendine, S.; Schofield, J.S.; Levitt, M.T.; Fink, J.B.; Rucker, D.F.

    2011-01-01

    At the Hanford Nuclear Site in Washington State, the Department of Energy oversees the containment, treatment, and retrieval of liquid high-level radioactive waste. Much of the waste is stored in single-shelled tanks (SSTs) built between 1943 and 1964. Currently, the waste is being retrieved from the SSTs and transferred into newer double-shelled tanks (DSTs) for temporary storage before final treatment. Monitoring the tanks during the retrieval process is critical to identifying leaks. An electrically-based geophysics monitoring program for leak detection and monitoring (LDM) has been successfully deployed on several SSTs at the Hanford site since 2004. The monitoring program takes advantage of changes in contact resistance that will occur when conductive tank liquid leaks into the soil. During monitoring, electrical current is transmitted on a number of different electrode types (e.g., steel cased wells and surface electrodes) while voltages are measured on all other electrodes, including the tanks. Data acquisition hardware and software allow for continuous real-time monitoring of the received voltages and the leak assessment is conducted through a time-series data analysis. The specific hardware and software combination creates a highly sensitive method of leak detection, complementing existing drywell logging as a means to detect and quantify leaks. Working in an industrial environment such as the Hanford site presents many challenges for electrical monitoring: cathodic protection, grounded electrical infrastructure, lightning strikes, diurnal and seasonal temperature trends, and precipitation, all of which create a complex environment for leak detection. In this discussion we present examples of challenges and solutions to working in the tank farms of the Hanford site.

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

    OpenAIRE

    D. Schertzer; S. Lovejoy; S. Lovejoy

    1994-01-01

    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 ...

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

    OpenAIRE

    Schertzer , D; Lovejoy , S.

    1994-01-01

    International audience; 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 conse...

  20. 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.

  1. Statistical mechanics of two-dimensional and geophysical flows

    International Nuclear Information System (INIS)

    Bouchet, Freddy; Venaille, Antoine

    2012-01-01

    The theoretical study of the self-organization of two-dimensional and geophysical turbulent flows is addressed based on statistical mechanics methods. This review is a self-contained presentation of classical and recent works on this subject; from the statistical mechanics basis of the theory up to applications to Jupiter’s troposphere and ocean vortices and jets. Emphasize has been placed on examples with available analytical treatment in order to favor better understanding of the physics and dynamics. After a brief presentation of the 2D Euler and quasi-geostrophic equations, the specificity of two-dimensional and geophysical turbulence is emphasized. The equilibrium microcanonical measure is built from the Liouville theorem. Important statistical mechanics concepts (large deviations and mean field approach) and thermodynamic concepts (ensemble inequivalence and negative heat capacity) are briefly explained and described. On this theoretical basis, we predict the output of the long time evolution of complex turbulent flows as statistical equilibria. This is applied to make quantitative models of two-dimensional turbulence, the Great Red Spot and other Jovian vortices, ocean jets like the Gulf-Stream, and ocean vortices. A detailed comparison between these statistical equilibria and real flow observations is provided. We also present recent results for non-equilibrium situations, for the studies of either the relaxation towards equilibrium or non-equilibrium steady states. In this last case, forces and dissipation are in a statistical balance; fluxes of conserved quantity characterize the system and microcanonical or other equilibrium measures no longer describe the system.

  2. Different integrated geophysical approaches to investigate archaeological sites in urban and suburban area.

    Science.gov (United States)

    Piro, Salvatore; Papale, Enrico; Zamuner, Daniela

    2016-04-01

    Geophysical methods are frequently used in archaeological prospection in order to provide detailed information about the presence of structures in the subsurface as well as their position and their geometrical reconstruction, by measuring variations of some physical properties. Often, due to the limited size and depth of an archaeological structure, it may be rather difficult to single out its position and extent because of the generally low signal-to-noise ratio. This problem can be overcome by improving data acquisition, processing techniques and by integrating different geophysical methods. In this work, two sites of archaeological interest, were investigated employing several methods (Ground Penetrating Radar (GPR), Electrical Resistivity Tomography (ERT), Fluxgate Differential Magnetic) to obtain precise and detailed maps of subsurface bodies. The first site, situated in a suburban area between Itri and Fondi, in the Aurunci Natural Regional Park (Central Italy), is characterized by the presence of remains of past human activity dating from the third century B.C. The second site, is instead situated in an urban area in the city of Rome (Basilica di Santa Balbina), where historical evidence is also present. The methods employed, allowed to determine the position and the geometry of some structures in the subsurface related to this past human activity. To have a better understanding of the subsurface, we then performed a qualitative and quantitative integration of this data, which consists in fusing the data from all the methods used, to have a complete visualization of the investigated area. Qualitative integration consists in graphically overlaying the maps obtained by the single methods; this method yields only images, not new data that may be subsequently analyzed. Quantitative integration is instead performed by mathematical and statistical solutions, which allows to have a more accurate reconstruction of the subsurface and generates new data with high

  3. UNMANNED AIRCRAFT SYSTEMS FOR RAPID NEAR SURFACE GEOPHYSICAL MEASUREMENTS

    Directory of Open Access Journals (Sweden)

    J. B. Stoll

    2013-08-01

    Full Text Available This paper looks at some of the unmanned aircraft systems (UAS options and deals with a magnetometer sensor system which might be of interest in conducting rapid near surface geophysical measurements. Few of the traditional airborne geophysical sensors are now capable of being miniaturized to sizes and payload within mini UAS limits (e.g. airborne magnetics, gamma ray spectrometer. Here the deployment of a fluxgate magnetometer mounted on an UAS is presented demonstrating its capability of detecting metallic materials that are buried in the soil. The effectiveness in finding ferrous objects (e.g. UXO, landslides is demonstrated in two case studies.

  4. Parts-based geophysical inversion with application to water flooding interface detection and geological facies detection

    Science.gov (United States)

    Zhang, Junwei

    I built parts-based and manifold based mathematical learning model for the geophysical inverse problem and I applied this approach to two problems. One is related to the detection of the oil-water encroachment front during the water flooding of an oil reservoir. In this application, I propose a new 4D inversion approach based on the Gauss-Newton approach to invert time-lapse cross-well resistance data. The goal of this study is to image the position of the oil-water encroachment front in a heterogeneous clayey sand reservoir. This approach is based on explicitly connecting the change of resistivity to the petrophysical properties controlling the position of the front (porosity and permeability) and to the saturation of the water phase through a petrophysical resistivity model accounting for bulk and surface conductivity contributions and saturation. The distributions of the permeability and porosity are also inverted using the time-lapse resistivity data in order to better reconstruct the position of the oil water encroachment front. In our synthetic test case, we get a better position of the front with the by-products of porosity and permeability inferences near the flow trajectory and close to the wells. The numerical simulations show that the position of the front is recovered well but the distribution of the recovered porosity and permeability is only fair. A comparison with a commercial code based on a classical Gauss-Newton approach with no information provided by the two-phase flow model fails to recover the position of the front. The new approach could be also used for the time-lapse monitoring of various processes in both geothermal fields and oil and gas reservoirs using a combination of geophysical methods. A paper has been published in Geophysical Journal International on this topic and I am the first author of this paper. The second application is related to the detection of geological facies boundaries and their deforation to satisfy to geophysica

  5. Joint inversion of geophysical data using petrophysical clustering and facies deformation wth the level set technique

    Science.gov (United States)

    Revil, A.

    2015-12-01

    Geological expertise and petrophysical relationships can be brought together to provide prior information while inverting multiple geophysical datasets. The merging of such information can result in more realistic solution in the distribution of the model parameters, reducing ipse facto the non-uniqueness of the inverse problem. We consider two level of heterogeneities: facies, described by facies boundaries and heteroegenities inside each facies determined by a correlogram. In this presentation, 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 of the geophysical data is performed in a Bayesian framework. We demonstrate the usefulness of this strategy using a first synthetic case for which we perform a joint inversion of gravity and galvanometric resistivity data with the stations 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 perform such deformation preserving prior topological properties of the facies throughout the inversion. With the help of prior facies petrophysical relationships and topological characteristic of each facies, we make posterior inference about multiple geophysical tomograms based on their corresponding geophysical data misfits. The method is applied to a second synthetic case showing that we can recover the heterogeneities inside the facies, the mean values for the petrophysical properties, and, to some extent, the facies boundaries using the 2D joint inversion of

  6. A Hands-on Approach to Teaching Geophysics through the University of Texas Institute for Geophysics Marine Geology and Geophysics Field Course in the Gulf of Mexico.

    Science.gov (United States)

    Duncan, D.; Davis, M. B.; Goff, J.; Gulick, S. P. S.; Fernandez-Vasquez, R. A.; Saustrup, S.

    2017-12-01

    The three week field course is offered to graduate and upper-level undergraduate students as hands-on instruction and training for marine geology and geophysics applications. Instructors provide theoretical and technical background of high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, sediment coring, grab sampling, and the sedimentology of resulting seabed samples in the initial phase of the course. The class then travels to the Gulf Coast for a week of at-sea field work. Over the last 10 years, field sites at Freeport, Port Aransas, and Galveston, TX, and Grand Isle, LA, have provided ideal locations for students to explore and investigate coastal and continental shelf processes through the application of geophysical techniques. Students with various backgrounds work in teams of four and rotate between two marine vessels: the R/V Scott Petty, a 26' vessel owned and operated by UTIG, and the R/V Manta, an 82' vessel owned and operated by NOAA. They assist with survey design, instrumentation setup and breakdown, data acquisition, trouble-shooting, data quality control, and safe instrumentation deployment and recovery. Teams also process data and sediment samples in an onshore field lab. During the final week, students visualize, integrate and interpret data for a final project using industry software. The course concludes with final presentations and discussions wherein students examine Gulf Coast geological history and sedimentary processes 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 students, three faculty, and three teaching assistants). Post-class, students may incorporate course data in senior honors or graduate thesis and are encouraged to publish and present results at national meetings. This course satisfies field experience requirements for

  7. 77 FR 19321 - Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf (OCS)

    Science.gov (United States)

    2012-03-30

    ... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Geological and Geophysical... Statement (PEIS) to evaluate potential environmental effects of multiple Geological and Geophysical (G&G... limited to, seismic surveys, sidescan-sonar surveys, electromagnetic surveys, geological and geochemical...

  8. EAST93: Geophysical traverse from the Transantarctic Mountains to the Wilkes Basin, East Antarctica

    Science.gov (United States)

    ten Brink, Uri S.; Bannister, Stephen

    1995-01-01

    The East Antarctic Seismic Traverse (EAST93) was a geophysical traverse designed to image the bedrock under the East Antarctic ice cap. The traverse started 10 km west of the Taylor Dome drill site and 25 km west of the exposed bedrock of the Transantarctic Mountains at Lashly Mt. and ended 323 km west of the drill site over the Wilkes subglacial basin (Fig. 1). The traverse was located subparallel to latitude 78° S starting 30-50 km north of the Victoria Land Traverse (1958-1959). It was carried out jointly by the U.S. Geological Survey and Stanford University, U.S.A., together with the Institute of Geological and Nuclear Sciences, and Victoria University, New Zealand, during December 1993 and January 1994. The geophysical traverse included 236 km of multichannel seismic reflection data at 150 m shot intervals, 312.5 km of gravity data collected at intervals of 2.1 km, 312.5 km of magnetic data (total field intensity) collected at average intervals of 0.5 km, and 205 km of ground penetrating radar at intervals of 77 m. Relative locations and elevations of the entire traverse were measured at intervals of 150 m by traditional surveying methods, and tied to three absolute locations measured by the Global Positioning System (GPS). EAST93 is the first large-scale geophysical traverse on the polar plateau to our knowledge since the early 1960s. As such, the experiment presented several logistical challenges: (1) how to collect regional seismic profiles during the short Antarctic summer; (2) how to keep the scientific instruments running with minimal protection in harsh conditions; and (3) how to combine daily moves of camp with full days of work. The scientific and logistical aspects of the project proceeded, in general, according to plan despite the harsh conditions and our lack of previous experience on the polar plateau. Two unanticipated problems affected the progress of the work: the strong wind which slowed seismic acquisition, and the break-down of one of the

  9. Engineering Geophysical Study of the Convocation Square, Kaduna

    African Journals Online (AJOL)

    Abdullahi et. al

    integrated techniques for engineering site investigations. The applications .... distribution, numerical techniques are more commonly used. For the 1-D case, ... the software, IPIWIN (version 3.0.1) developed by the Geophysics. Group Moscow ...

  10. Synthesis of borehole geophysical data at the Underground Research Laboratory, Manitoba, Canada

    International Nuclear Information System (INIS)

    Keys, W.S.

    1984-07-01

    A suite of borehole-geophysical logs, supported by core data, was used to describe the rock matrix and fractures in a granitic pluton near Lac du Bonnet, Manitoba, Canada. The site is being developed by Atomic Energy of Canada Limited, as an underground research laboratory to conduct geotechnical research and to validate predictive models as part of Canada's nuclear-fuel, waste-management program. However, the site is not planned to be used for waste disposal. Geophysical well logs were used to distinguish and correlate rock types and fractures between drill holes. Two significant fracture zones that are two of the major zones of ground-water movement at the site were identified by acoustic-televiewer logs. A new heat-pulse flowmeter provided repeatable measurements of very low-velocity, vertical flow in drill holes which enabled the identification of specific fractures that were transmitting water. Borehole gamma spectra showed that some fractures are enriched in uranium, and others may be depleted. This study demonstrates some of the advantages of synthesizing available borehole-geophysical logs at a site in fractured plutonic rocks and indicates how this information can contribute to an understanding of the geophysical conditions at the site

  11. INGDB-90. The International Neutron Nuclear Data Base for geophysics applications

    International Nuclear Information System (INIS)

    Kocherov, N.P.; McLaughline, P.K.

    1991-01-01

    This document describes the contents of the International Neutron Nuclear Data Base for applications in nuclear geophysics, such as borehole logging and mineral analysis. It contains neutron cross-section data from 19 elements and their isotopes of primary importance in geophysics, plus a data file with neutron spectra of three frequently used neutron sources. The INGDB-90 file is available, cost free, from the IAEA Nuclear Data Section on PC diskettes or on magnetic tape. (author). 9 refs

  12. Preface: Current perspectives in modelling, monitoring, and predicting geophysical fluid dynamics

    Science.gov (United States)

    Mancho, Ana M.; Hernández-García, Emilio; López, Cristóbal; Turiel, Antonio; Wiggins, Stephen; Pérez-Muñuzuri, Vicente

    2018-02-01

    The third edition of the international workshop Nonlinear Processes in Oceanic and Atmospheric Flows was held at the Institute of Mathematical Sciences (ICMAT) in Madrid from 6 to 8 July 2016. The event gathered oceanographers, atmospheric scientists, physicists, and applied mathematicians sharing a common interest in the nonlinear dynamics of geophysical fluid flows. The philosophy of this meeting was to bring together researchers from a variety of backgrounds into an environment that favoured a vigorous discussion of concepts across different disciplines. The present Special Issue on Current perspectives in modelling, monitoring, and predicting geophysical fluid dynamics contains selected contributions, mainly from attendants of the workshop, providing an updated perspective on modelling aspects of geophysical flows as well as issues on prediction and assimilation of observational data and novel tools for describing transport and mixing processes in these contexts. More details on these aspects are discussed in this preface.

  13. Synthesis of the works of geophysical (electrical soundings) carried out in the region of the anomalies of Yerba Sola (Cerro Largo) Uruguay

    International Nuclear Information System (INIS)

    Perrin, J.

    1983-01-01

    In this report has been studied geographical localization, geology, geophysics prospection, equipment and methods used and their results in Yerba Sola anomalies Province Cerro Largo and Fraile Muerto formation

  14. Prospect of Continuous VLBI Measurement of Earth Rotation in Monitoring Geophysical Fluids

    Science.gov (United States)

    Chao, Benjamin F.; Ma, Chopo; Clark, Thomas

    1998-01-01

    Large-scale mass transports in the geophysical fluids of the Earth system excite Earth's rotational variations in both length-of-day and polar motion. The excitation process is via the conservation of angular momentum. Therefore Earth rotation observations contain information about the integrated angular momentum (consisting of both the mass term and the motion term) of the geophysical fluids, which include atmosphere, hydrosphere, mantle, and the outer and inner cores. Such global information is often important and otherwise unattainable depending on the nature of the mass transport, its magnitude and time scale. The last few years have seen great advances in VLBI measurement of Earth rotation in precision and temporal resolution. These advances have opened new. areas in geophysical fluid studies, such as oceanic tidal angular momentum, atmospheric tides, Earth librations, and rapid atmospheric angular momentum fluctuations. Precision of 10 microseconds in UTI and 200 microarcseconds in polar motion can now be achieved on hourly basis. Building upon this heritage, the multi-network geodetic VLBI project, Continuous Observation of the Rotation of the Earth (CORE), promises to further these studies and to make possible studies on elusive but tell-tale geophysical processes such as oscillatory modes in the core and in the atmosphere. Currently the early phase of CORE is underway. Within a few years into the new mellinnium, the upcoming space gravity missions (such as GRACE) will measure the temporal variations in Earth's gravitational field, thus providing complementary information to that from Earth rotation study for a better understanding of global geophysical fluid processes.

  15. Prehistory of geophysical service establishment in the National Nuclear Center of the Republic of Kazakhstan

    International Nuclear Information System (INIS)

    Vanchugov, A.G.

    2003-01-01

    To look to the future it is necessary, seeing the present, not to forget the past. Obviously it is important to know 'how was it?', 'in the beginning was the word' - the word of the Ministry of the Republic of Kazakhstan of May 15, 1992 about establishment of the National Nuclear Center of the Republic of Kazakhstan. Originally a geophysical service formed the National Nuclear Center RK as Geophysical Party 35 and Borovoe Geophysical Observatory. (author)

  16. An Exploration Geophysics Course With an Environmental Focus for an Urban Minority Institution

    Science.gov (United States)

    Kenyon, P. M.

    2004-12-01

    A hands-on exploration geophysics field course with an environmental focus has been developed with NSF support for use at the City College of New York in Manhattan. To maximize access for the students, no prerequisites beyond introductory earth science and physics are required. The course is taught for three hours on Saturday mornings. This has resulted in it attracting not only regular City College students, but also earth science teachers studying for alternate certification or Master's degrees. After a brief introduction to the nature of geophysics and to concepts in data processing, the course is taught in four three-week modules, one each on seismology, resistivity surveying, electromagnetic ground conductivity, and magnetic measurements. Each module contains one week of theory, a field experience, computer data analysis, and a final report. Field exercises are planned to emphasize teamwork and include realistic urban applications of the techniques. Student surveys done in conjunction with this course provide insights into the motivations and needs of the mostly minority students taking it. In general, these students come to the course already comfortable with teamwork and with working in the field. The questionnaires indicate that their greatest need is increased knowledge of the methods of geophysics and of the problems that can be attacked using it. Most of the students gave high ratings to the course, citing the fieldwork as the part that they most enjoyed. The results of these surveys will be presented, along with examples of the field exercises used. The computer analysis assignments written for this course will also be available.

  17. Geophysical survey at Tell Barri (Syria)

    Science.gov (United States)

    Florio, Giovanni; Cella, Federico; Pierobon, Raffaella; Castaldo, Raffaele; Castiello, Gabriella; Fedi, Maurizio

    2010-05-01

    A geophysical survey at the archaeological site of Tell Barri (Northeasterm Syria) was carried out. The Tell (Arab word for "hill") is 32 m high with a whole covered area of 37 hectares. The Tell, with its huge dimensions and with a great amount of pottery on the surface, is a precious area to study the regional history from IV mill. BC to Islamic and Medieval period. The geophysical study consisted in magnetic and electromagnetic measurements in the lower town area. The aim of this survey was to provide evidence of the presence of buried archaeological structures around an already excavated area. The wall structures in the Tell Barri are made by backed or crude clay bricks. The instrument used for the magnetic survey was an Overhauser-effect proton magnetometer (Gem GSM-19GF), in gradiometric configuration. The electromagnetic instrument used, Geonics Ltd. EM31, implements a Frequency Domain Electromagnetic Method (FDEM). It was used in vertical coils configuration, and this choice should grant a maximum theoretical investigation depth of about 6 m. Before starting the measurements on a larger scale, we conducted a magnetic and EM test profile on some already excavated, outcropping, baked bricks walls. Results were encouraging, because clear and strong magnetic and EM anomalies were recorded over the outcropping walls. However, in the survey area these structures are covered by 3 to 4 meters of clay material and the increased sensors-structures distance will reduce the anomalies amplitude. Moreover, the cover material is disseminated with bricks, basalt blocks and ceramics, all of which have relevant magnetic properties. After magnetic surveying some 50 m side square areas, we verified that unfortunately their effect resulted to be dominant with respect to the deeper wall structures, degrading too much the signal-to-noise ratio. The processing and analysis of magnetic data is however currently underway and will determine decisions about further use of this method

  18. Imaging normal faults in alluvial fans using geophysical techniques: Field example from the coast of Gulf of Aqaba, Saudi Arabia

    KAUST Repository

    Hanafy, Sherif M.; Jonsson, Sigurjon; Klinger, Yann

    2014-01-01

    In this work we use geophysical methods to locate and characterize active faults in alluvial sediments. Since only subtle material and velocity contrasts are expected across the faults, we used seismic refraction tomography and 2D resistivity

  19. Geological characterization in urban areas based on geophysical mapping: A case study from Horsens, Denmark

    DEFF Research Database (Denmark)

    Andersen, Theis Raaschou; Poulsen, Søren Erbs; Thomsen, Peter

    2018-01-01

    Geophysical mapping in urban areas. Detailed 3D geological model of the area. Mapping contaminant plume......Geophysical mapping in urban areas. Detailed 3D geological model of the area. Mapping contaminant plume...

  20. Geophysical exploration for uranium in Suryamalai batholith, Salem District, Tamil Nadu, India

    Energy Technology Data Exchange (ETDEWEB)

    Anantharaman, K B; Sethuram, S [Department of Atomic Energy, Hyderabad (India). Atomic Minerals Div.

    1984-08-01

    Abnormally radioactive granitoids are targets of uranium exploration because they can be the source for uranium deposits as well as the hosts. Significant uranium mineralization is known to occur northwest of Suryamalai granite batholith at Kullampatti situated 40 km southwest of Salem. This paper embodies the geophysical exploration for uranium, using results of magnetic and radiometric methods. The investigations revealed that uranium mineralization is structurally controlled and such structures have magnetic expression. Incidentally, correlation of anomalous content of W with U is also brought to light.

  1. Commerce geophysical lineament - Its source, geometry, and relation to the Reelfoot rift and New Madrid seismic zone

    Science.gov (United States)

    Langenheim, V.E.; Hildenbrand, T.G.

    1997-01-01

    The Commerce geophysical lineament is a northeast-trending magnetic and gravity feature that extends from central Arkansas to southern Illinois over a distance of ???400 km. It is parallel to the trend of the Reelfoot graben, but offset ???40 km to the northwest of the western margin of the rift floor. Modeling indicates that the source of the aeromagnetic and gravity anomalies is probably a mafic dike swarm. The age of the source of the Commerce geophysical lineament is not known, but the linearity and trend of the anomalies suggest a relationship with the Reelfoot rift, which has undergone episodic igneous activity. The Commerce geophysical lineament coincides with several topographic lineaments, movement on associated faults at least as young as Quaternary, and intrusions of various ages. Several earthquakes (Mb > 3) coincide with the Commerce geophysical lineament, but the diversity of associated focal mechanisms and the variety of surface structural features along the length of the Commerce geophysical lineament obscure its relation to the release of present-day strain. With the available seismicity data, it is difficult to attribute individual earthquakes to a specific structural lineament such as the Commerce geophysical lineament. However, the close correspondence between Quaternary faulting and present-day seismicity along the Commerce geophysical lineament is intriguing and warrants further study.

  2. Results of Tank-Leak Detection Demonstration Using Geophysical Techniques at the Hanford Mock Tank Site-Fiscal Year 2001

    International Nuclear Information System (INIS)

    Barnett, D BRENT.; Gee, Glendon W.; Sweeney, Mark D.

    2002-01-01

    During July and August of 2001, Pacific Northwest National Laboratory (PNNL), hosted researchers from Lawrence Livermore and Lawrence Berkeley National laboratories, and a private contractor, HydroGEOPHYSICS, Inc., for deployment of the following five geophysical leak-detection technologies at the Hanford Site Mock Tank in a Tank Leak Detection Demonstration (TLDD): Electrical Resistivity Tomography (ERT); Cross-Borehole Electromagnetic Induction (CEMI) ; High-Resolution Resistivity (HRR); Cross-Borehole Radar (XBR); Cross-Borehole Seismic Tomography (XBS). Under a ''Tri-party Agreement'' with Federal and state regulators, the U.S. Department of Energy will remove wastes from single-shell tanks (SSTs) and other miscellaneous underground tanks for storage in the double-shell tank system. Waste retrieval methods are being considered that use very little, if any, liquid to dislodge, mobilize, and remove the wastes. As additional assurance of protection of the vadose zone beneath the SSTs, tank wastes and tank conditions may be aggressively monitored during retrieval operations by methods that are deployed outside the SSTs in the vadose zone

  3. Geophysical studies of the Crump Geyser known geothermal resource area, Oregon, in 1975

    Science.gov (United States)

    Plouff, Donald

    2006-01-01

    sediment thickness was estimated at 820 meters. A three-dimensional gravity model would have yielded a greater thickness. Audiomagnotelluric measurements were not made as far south as the location of the gravity low, as determined in the field, due to a lack of communication at that time. A boat was borrowed to collect gravity measurements along the edge of Crump Lake, but the attempt was curtailed by harsh, snowy weather on May 21, 1975, which shortly followed days of hot temperature. Most of the geophysical data and illustrations in Appendix 1 have been published (Gregory and Martinez, 1975; Plouff, 1975; and Plouff and Conradi, 1975), and Donald Plouff (1986) discussed a gravity interpretation of Warner Valley at the Fall 1986 American Geophysical Union meeting in San Francisco. Further interpretation of possible subsurface geologic sources of geophysical anomalies was not discussed in Appendix 1. For example, how were apparent resistivity lows (Appendix 1, figs. 3-6) centered near Crump Geyser affected by a well and other manmade electrically conductive or magnetic objects? What is the geologic significance of the 15-milligal eastward decrease across Warner Valley? The explanation that the two-dimensional gravity model (Appendix 1, fig. 14) was based on an inverse iterative method suggested by Bott (1960) was not included. Inasmuch as there was no local subsurface rock density distribution information to further constrain the gravity model, the three-dimensional methodology suggested by Plouff (1976) was not attempted. Inasmuch as the associated publication by Plouff (1975), which released the gravity data, is difficult to obtain and not in digital format, that report is reproduced in Appendix 2. Two figures of the publication are appended to the back of the text. A later formula for the theoretical value of gravity for the given latitudes at sea level (International Association of Geodesy, 1971) should be used to re-compute gravity anomalies. To merge t

  4. Multi-scale, multi-method geophysical investigations of the Valles Caldera

    Science.gov (United States)

    Barker, J. E.; Daneshvar, S.; Langhans, A.; Okorie, C.; Parapuzha, A.; Perez, N.; Turner, A.; Smith, E.; Carchedi, C. J. W.; Creighton, A.; Folsom, M.; Bedrosian, P.; Pellerin, L.; Feucht, D. W.; Kelly, S.; Ferguson, J. F.; McPhee, D.

    2017-12-01

    In 2016, the Summer of Applied Geophysical Experience (SAGE) program, in cooperation with the National Park Service, began a multi-year investigation into the structure and evolution of the Valles Caldera in northern New Mexico. The Valles Caldera is a 20-km wide topographic depression in the Jemez Mountains volcanic complex that formed during two massive ignimbrite eruptions at 1.65 and 1.26 Ma. Post-collapse volcanic activity in the caldera includes the rise of Redondo peak, a 1 km high resurgent dome, periodic eruptions of the Valles rhyolite along an inferred ring fracture zone, and the presence of a geothermal reservoir beneath the western caldera with temperatures in excess of 300°C at a mere 2 km depth. Broad sediment-filled valleys associated with lava-dammed Pleistocene lakes occupy much of the northern and southeastern caldera. SAGE activities to date have included collection of new gravity data (>120 stations) throughout the caldera, a transient electromagnetic (TEM) survey of Valle Grande, reprocessing of industrial magnetotelluric (MT) data collected in the 1980s, and new MT data collection both within and outside of the caldera. Gravity modeling provides constraints on the pre-Caldera structure, estimates of the thickness of Caldera fill, and reveals regional structural trends reflected in the geometry of post-Caldera collapse. At a more local scale, TEM-derived resistivity models image rhyolite flows radiating outward from nearby vents into the lacustrine sediments filling Valle Grande. Resistivity models along a 6-km long profile also provide hints of structural dismemberment along the inferred Valles and Toledo ring fracture zones. Preliminary MT modeling at the caldera scale reveals conductive caldera fill, the resistive crystalline basement, and an enigmatic mid-crustal conductor likely related to magmatic activity that post-dates caldera formation.

  5. Geophysical Exploration on the Structure of Volcanoes: Two Case Histories

    Energy Technology Data Exchange (ETDEWEB)

    Furumoto, A. S.

    1974-01-01

    Geophysical methods of exploration were used to determine the internal structure of Koolau Volcano in Hawaii and of Rabaul Volcano in New Guinea. By use of gravity and seismic data the central vent or plug of Koolau Volcano was outlined. Magnetic data seem to indicate that the central plug is still above the Curie Point. If so, the amount of heat energy available is tremendous. As for Rabaul Volcano, it is located in a region characterized by numerous block faulting. The volcano is only a part of a large block that has subsided. Possible geothermal areas exist near the volcano but better potential areas may exist away from the volcano.

  6. Application of integrated Landsat, geochemical and geophysical data in mineral exploration

    International Nuclear Information System (INIS)

    Conradsen, K.; Nilsson, G.; Thyrsted, T.; Gronlands Geologiske Undersogelse, Copenhagen, Denmark)

    1985-01-01

    In South Greenland (20000 sq. km) a remote sensing investigation is executed in connection with uranium exploration. The investigation includes analysis of Landsat data, conversion of geological, geochemical and geophysical data to image format compatible with Landsat images, and analysis of the total set of integrated data. The available geochemical data consisted of samples from 2000 sites, analyzed for U, K, Rb, Sr, Nb, Ga, Y, and Fe. The geophysical data comprised airborne gamma-spectrometric measurements and aeromagnetic data. The interpolation routines consisted of a kriging procedure for the geochemical data and a minimum curvature routine for the geophysical data. The analysis of the integrated data set is at a preliminary stage. As example a composite image showing Landsat channel 7, magnetic values, and Fe values as respectively intensity, hue and saturation is analyzed. It reveals alkaline intrusions and basaltic layers as anomalies while other anomalies cannot be accounted for on the basis of the present geological knowledge. 12 references

  7. Comparison study to the use of geophysical methods at archaeological sites observed by various remote sensing techniques in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Křivánek, Roman

    2017-01-01

    Roč. 7, č. 3 (2017), č. článku 81. ISSN 2076-3263 Grant - others:AV ČR(CZ) R300021421 Institutional support: RVO:67985912 Keywords : archaeological prospection * remote sensing * non-destructive archaeology * geophysical survey Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology http://www.mdpi.com/2076-3263/7/3/81/pdf

  8. Geophysical signatures of a fracture controlled U-mineralisation: a case study from Mulapalle area, Cuddapah district, Andhra Pradesh

    International Nuclear Information System (INIS)

    Rao, R.L.N.; Sethuram, S.; Rao, B.N.; Tiku, K.L.; Ram, Subhash

    2000-01-01

    Geophysical methods have been extensively used for delineation of structural features such as fractures and shear zones which often control and host economic mineralisation. Numerous fractures hosting uranium mineralisation and confined to younger intrusives and leucogranites occur within basement gneissic complex on the southwestern margin of the Mesoproterozoic Cuddapah basin. The geophysical signatures of one such mineralised fracture zone near Mulapalle are discussed. Mineralised fractures are mostly confined to a zone of cataclastic rocks characterised by widely varying magnetic character with respect to the surroundings. A strong redox barrier associated with the mineralisation is revealed by self-potential data. The mineralised zone is also indicated by a higher order resistivity attributable to the enrichment of silica in the fracture zone. (author)

  9. Petroleum geophysics

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    The book is compiled from a series of e-learning modules. GeoCLASS is an e-learning system with contents from petroleum geophysics. It is the result of collaboration between professors at the University of Bergen and the University of Oslo, and its material has been used as curriculum in master program courses at these universities for several years. Using a unique feature to GeoCLASS, these advanced scientific topics are presented on multiple levels. The introductions open the door to this vast pool of knowledge, accessible even for high school students. Enter the door, and you enter the modules. Various levels of content are presented, and the more advanced levels can be shielded from the regular user, and only accessed by those with particular interest. The chapters in the book are: Elastic waves; Survey planning; Seismic acquisition; Basic seismic signal theory and processing; Seismic imaging; Seismic attributes; Rock physics; Reservoir monitoring. (AG)

  10. Integrated geophysical survey to recognize ancient Picentia’s buried walls, in the Archaeological Park of Pontecagnano – Faiano (Southern Italy

    Directory of Open Access Journals (Sweden)

    A. Rossi

    2008-06-01

    Full Text Available There is no information on previous geophysical prospections carried out in the Archaeological Park of Pontecagnano- Faiano, in order to reconstruct the ancient settlement of Picentia, an Etrusco-Campanian and Roman settlement near Salerno (Southern Italy. Therefore, an integrated geophysical survey based on magnetic, geoelectric and ground-penetrating radar (GPR prospections was executed in the Park. The methods provided a basic map of buried ancient structures at depth from 0.1-0.2 to about 1.5 meters. Magnetic data were processed analyzing the analytical signal of the vertical derivative of the measured gradient and this substantially reduced a strong fence effect. The results of the geophysical prospections showed archaeological structures located close to those discovered in the excavated areas. The shape of the anomalies are usually elongated with well-defined geometrical characteristics. Many anomalies are arranged along orthogonal directions and they are very coherent with the excavated structures, namely the quarters structures of the ancient Picentia.

  11. Airborne geophysical surveys conducted in western Nebraska, 2010: contractor reports and data

    Science.gov (United States)

    ,

    2014-01-01

    This report contains three contractor reports and data files for an airborne electromagnetic survey flown from June 28 to July 7, 2010. The first report; “SkyTEM Survey: Nebraska, USA, Data” describes data aquisition and processing from a time-domain electromagnetic and magnetic survey performed by SkyTEM Canada, Inc. (the North American SkyTEM subsidiary), in western Nebraska, USA. Digital data for this report are given in Appendix 1. The airborne geophysical data from the SkyTEM survey subsequently were processed and inverted by Aarhus Geophysics ApS, Aarhus, Denmark, to produce resistivity depth sections along each flight line. The result of that processing is described in two reports presented in Appendix 2, “Processing and inversion of SkyTEM data from USGS Area UTM–13” and “Processing and inversion of SkyTEM data from USGS Area UTM–14.” Funding for these surveys was provided by the North Platte Natural Resources District, the South Platte Natural Resources District, and the Twin Platte Natural Resources District, in Scottsbluff, Sidney, and North Platte, Nebraska, respectively. Any additional information concerning the geophysical data may be obtained from the U.S. Geological Survey Crustal Geophysics and Geochemistry Science Center, Denver Colorado.

  12. Case studies: Soil mapping using multiple methods

    Science.gov (United States)

    Petersen, Hauke; Wunderlich, Tina; Hagrey, Said A. Al; Rabbel, Wolfgang; Stümpel, Harald

    2010-05-01

    Soil is a non-renewable resource with fundamental functions like filtering (e.g. water), storing (e.g. carbon), transforming (e.g. nutrients) and buffering (e.g. contamination). Degradation of soils is meanwhile not only to scientists a well known fact, also decision makers in politics have accepted this as a serious problem for several environmental aspects. National and international authorities have already worked out preservation and restoration strategies for soil degradation, though it is still work of active research how to put these strategies into real practice. But common to all strategies the description of soil state and dynamics is required as a base step. This includes collecting information from soils with methods ranging from direct soil sampling to remote applications. In an intermediate scale mobile geophysical methods are applied with the advantage of fast working progress but disadvantage of site specific calibration and interpretation issues. In the framework of the iSOIL project we present here some case studies for soil mapping performed using multiple geophysical methods. We will present examples of combined field measurements with EMI-, GPR-, magnetic and gammaspectrometric techniques carried out with the mobile multi-sensor-system of Kiel University (GER). Depending on soil type and actual environmental conditions, different methods show a different quality of information. With application of diverse methods we want to figure out, which methods or combination of methods will give the most reliable information concerning soil state and properties. To investigate the influence of varying material we performed mapping campaigns on field sites with sandy, loamy and loessy soils. Classification of measured or derived attributes show not only the lateral variability but also gives hints to a variation in the vertical distribution of soil material. For all soils of course soil water content can be a critical factor concerning a succesful

  13. Integrated geophysical and geological methods to investigate the inner and outer structures of the Quaternary Mýtina maar (W-Bohemia, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Flechsig, C.; Heinicke, J.; Mrlina, Jan; Kämpf, H.; Nickschick, T.; Schmidt, A.; Bayer, Tomáš; Günther, T.; Rücker, C.; Seidel, E.; Seidl, Michal

    2015-01-01

    Roč. 104, č. 8 (2015), s. 2087-2105 ISSN 1437-3254 R&D Projects: GA MŠk LM2010008 Institutional support: RVO:67985530 Keywords : Eger Rift * Quaternary maar volcanism * Mýtina maar * geophysical and geological survey Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.133, year: 2015

  14. Software complex for geophysical data visualization

    Science.gov (United States)

    Kryukov, Ilya A.; Tyugin, Dmitry Y.; Kurkin, Andrey A.; Kurkina, Oxana E.

    2013-04-01

    The effectiveness of current research in geophysics is largely determined by the degree of implementation of the procedure of data processing and visualization with the use of modern information technology. Realistic and informative visualization of the results of three-dimensional modeling of geophysical processes contributes significantly into the naturalness of physical modeling and detailed view of the phenomena. The main difficulty in this case is to interpret the results of the calculations: it is necessary to be able to observe the various parameters of the three-dimensional models, build sections on different planes to evaluate certain characteristics and make a rapid assessment. Programs for interpretation and visualization of simulations are spread all over the world, for example, software systems such as ParaView, Golden Software Surfer, Voxler, Flow Vision and others. However, it is not always possible to solve the problem of visualization with the help of a single software package. Preprocessing, data transfer between the packages and setting up a uniform visualization style can turn into a long and routine work. In addition to this, sometimes special display modes for specific data are required and existing products tend to have more common features and are not always fully applicable to certain special cases. Rendering of dynamic data may require scripting languages that does not relieve the user from writing code. Therefore, the task was to develop a new and original software complex for the visualization of simulation results. Let us briefly list of the primary features that are developed. Software complex is a graphical application with a convenient and simple user interface that displays the results of the simulation. Complex is also able to interactively manage the image, resize the image without loss of quality, apply a two-dimensional and three-dimensional regular grid, set the coordinate axes with data labels and perform slice of data. The

  15. Application of borehole geophysics to fracture identification and characterization in low porosity limestones and dolostones

    International Nuclear Information System (INIS)

    Haase, C.S.; King, H.L.

    1986-01-01

    Geophysical logging was conducted in exploratory core holes drilled for geohydrological investigations at three sites used for waste disposal on the US Department of Energy's Oak Ridge Reservation. Geophysical log response was calibrated to borehole geology using the drill core. Subsequently, the logs were used to identify fractures and fractured zones and to characterize the hydrologic activity of such zones. Results of the study were used to identify zones of ground water movement and to select targets for subsequent piezometer and monitoring well installation. Neutron porosity, long- and short-normal resistivity, and density logs exhibit anomalies only adjacent to pervasively fractured zones and rarely exhibit anomalies adjacent to individual fractures, suggesting that such logs have insufficient resolution to detect individual fractures. Spontaneous potential, single point resistance, acoustic velocity, and acoustic variable density logs, however, typically exhibit anomalies adjacent to both individual fractures and fracture zones. Correlation is excellent between fracture density logs prepared from the examination of drill core and fractures identified by the analysis of a suite of geophysical logs that have differing spatial resolution characteristics. Results of the study demonstrate the importance of (1) calibrating geophysical log response to drill core from a site, and (2) running a comprehensive suite of geophysical logs that can evaluate both large- and small-scale rock features. Once geophysical log responses to site-specific geological features have been established, logs provide a means of identifying fracture zones and discriminating between hydrologically active and inactive fracture zones. 9 figs

  16. From Mathematical Monsters to Generalized Scale Invariance in Geophysics: Highlights of the Multifractal Saga

    Science.gov (United States)

    Schertzer, D. J.; Tchiguirinskaia, I.; Lovejoy, S.

    2013-12-01

    Fractals and multifractals are very illustrative of the profound synergies between mathematics and geophysics. The book ';Fractal Geometry of Nature' (Mandelbrot, 1982) brilliantly demonstrated the genericity in geophysics of geometric forms like Cantor set, Peano curve and Koch snowflake, which were once considered as mathematical monsters. However, to tame the geophysical monsters (e.g. extreme weather, floods, earthquakes), it was required to go beyond geometry and a unique fractal dimension. The concept of multifractal was coined in the course of rather theoretical debates on intermittency in hydrodynamic turbulence, sometimes with direct links to atmospheric dynamics. The latter required a generalized notion of scale in order to deal both with scale symmetries and strong anisotropies (e.g. time vs. space, vertical vs. horizontal). It was thus possible to show that the consequences of intermittency are of first order, not just 'corrections' with respect to the classical non-intermittent modeling. This was in fact a radical paradigm shift for geophysics: the extreme variability of geophysical fields over wide ranges of scale, which had long been so often acknowledged and deplored, suddenly became handy. Recent illustrations are the possibility to track down in large date sets the Higgs boson of intermittence, i.e. a first order multifractal phase transition leading to self-organized criticality, and to simulate intermittent vector fields with the help of Lie cascades, based for instance on random Clifford algebra. It is rather significant that this revolution is no longer limited to fundamental and theoretical problems of geophysics, but now touches many applications including environmental management, in particular for urban management and resilience. These applications are particularly stimulating when taken in their full complexity.

  17. Massive Sulphide Exploration at the Mid-Atlantic Ridge 26oN: an interdisciplinary geophysical study

    Science.gov (United States)

    Gehrmann, R. A. S.; Hölz, S.; Jegen, M. D.; Graber, S.; Szitkar, F.; Petersen, S.; Yeo, I. A.; North, L. J.; Gil, A.; Vardy, M. E.; Haroon, A.; Schroeder, H.; Bialas, J.; Tan, Y. Y.; Attias, E.; Sommer, M.; Minshull, T. A.; Murton, B. J.

    2017-12-01

    During the summer 2016 two cruises (M127 and JC138) conducted an interdisciplinary survey as part of the EU FP7 project `Blue Mining' in the Trans-Atlantic Geotraverse (TAG) hydrothermal field, at the Mid-Atlantic Ridge (26° N), to study the geophysical and geochemical signature of extinct seafloor massive sulphide (eSMS) deposits. The survey comprised AUV-based high-resolution bathymetric mapping, magnetic and self-potential data acquisition, reflection and refraction seismic imaging and three types of controlled source electromagnetic (CSEM) experiments (Geomar, UoS). Additionally seafloor coring, drilling and video imaging (NOC, University of Lisbon, BGS) were realized. Laboratory measurements of physical and chemical properties were taken on and post-cruise from rock samples and sediment cores. Here, we present results from the geophysical data analysis with emphasis on the electromagnetic studies in respect to eSMS detection. Six multi-kilometre-long profiles were acquired with the towed CSEM experiment (UoS) and preliminary results indicate the sensitivity to the conductive eSMS deposits and the resistive background to a depth of about 200 m. The system is also sensitive to the rough topography and interpretation of eSMS deposits requires validation from other methods such as measurements with the MARTEMIS system, a seafloor source-receiver coil (Geomar), which were conducted in two collocated work areas for high-resolution imaging with a depth penetration of up to 50 m. Each geophysical method is sensitive to different SMS characteristics, for example, bathymetric and seismic data are sensitive to the shape and structure of the whole deposit, magnetic data are susceptive to the hydrothermal alteration of magnetic minerals, and self-potential and electromagnetic data respond to the electrically conductive sulphide bodies. Each method has different resolution, penetration depths and challenges with the rough-topographic terrain and navigation. Only

  18. A positioning and data logging system for surface geophysical surveys

    International Nuclear Information System (INIS)

    Nyquist, J.E.; Blair, M.S.

    1988-01-01

    The Ultrasonic Ranging and Data System (USRADS) developed at ORNL is being adapted to work with two commercially available geophysical instruments: a magnetometer and an EM31 terrain conductivity meter. Geophysical surveys have proven an important preliminary step in investigating hazardous waste sites. Magnetometers and terrain conductivity meters are used to locate buried drums, trenches, conductive contaminant plumes and map regional changes in geology. About half the field time of a typical geophysical investigation is spent surveying the position of the grid points at which the measurements will be made. Additional time is lost and errors may be made recording instrument values in field notebooks and transcribing the data to a computer. Developed for gamma radiation surveys, the USRAD system keeps track of the surveyor's position automatically by triangulating on an ultrasonic transmitter carried in a backpack. The backpack also contains a radio transmitter that sends the instrument's reading coincident with the ultrasonic pulse. The surveyor's position and the instrument's reading are recorded by a portable computer which can plot the data to check the survey's progress. Electronic files are stored in a form compatible with AutoCAD to speed report writing. 7 refs., 3 figs

  19. Borehole geophysical investigations of Lavia deep testhole, Finland

    International Nuclear Information System (INIS)

    Saksa, Pauli

    1985-02-01

    According to the Goverment's decision in principle in 1983 Industrial Power Company Ltd (TVO) is making preparations for all the steps of final disposal of the spent fuel produced by its power plants. Before the actual site investigation phase, TVO drilled a deep borehole in Lavia, Western Finland. The borehole is used during 1984-85 for testing investigation techniques and methods used for bedrock characterization. Borehole geophysical loggings performed in Lavia consisted of galvanic electrical, transient electromagnetic, radiometric, temperature, seismic and magnetic msurements. This composite survey provided both lithological and structural information of rock mass. The neutron-neutron, density, natural gamma radiation and susceptibility methods characterized rock type. Fracturing and its type could be interpreted most effectively with resistivity, acoustic P-wave velocity and density logs. Temperature and tube-wave measurements revealed several fractured zones related to possible water flow in rock. Lavia investigations indicated that a high quality of instrumentation and careful calibration are necessary for site investigations. The large amount of log data also requires efficient data collection and processing systems both in the field and laboratory. (author)

  20. 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

  1. Geophysical Research Letters: New policies improve top-cited geosciences journal

    Science.gov (United States)

    Calais, Eric; Diffenbaugh, Noah; D'Odorico, Paolo; Harris, Ruth; Knorr, Wolfgang; Lavraud, Benoit; Mueller, Anne; Peterson, William; Rignot, Eric; Srokosz, Meric; Strutton, Peter; Tyndall, Geoff; Wysession, Michael; Williams, Paul

    2010-01-01

    Geophysical Research Letters (GRL) is the American Geophysical Union's premier journal of fast, groundbreaking communication. It rapidly publishes high- impact,letter-length articles, and it is the top-cited multidisciplinary geosciences journal over the past 10 years, with an impact factor that increased again in 2009, to 3.204. For manuscripts submitted to GRL, the median time to first and final decision is 23 and 27 days, respectively—a 35% improvement since 2007—and the median time from submission to publication is 13 weeks for 90% of GRL papers—a 25% improvement since 2007. Among high-impact publications in the geosciences, GRL has the fastest turnaround.

  2. Stochastic resonance for exploration geophysics

    OpenAIRE

    Omerbashich, Mensur

    2008-01-01

    Stochastic resonance (SR) is a phenomenon in which signal to noise (SN) ratio gets improved by noise addition rather than removal as envisaged classically. SR was first claimed in climatology a few decades ago and then in other disciplines as well. The same as it is observed in natural systems, SR is used also for allowable SN enhancements at will. Here I report a proof of principle that SR can be useful in exploration geophysics. For this I perform high frequency GaussVanicek variance spectr...

  3. Geophysics report of Santa Rosa place Canelones province

    International Nuclear Information System (INIS)

    Cicalese, H.; Mari, C.; Lema, F.

    1985-01-01

    The Geophysical Division of the DINAMIGE has carried out several vertical electric well of long reach, with the purpose of estimating the basaltic mantel power of Arapey Formation , the thickness of the deep Tacuarembo Yaguari aquifer and the depth of the crystalline basement.

  4. Development of geophysical data management system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tai-Sup; Lee, Sang-Kyu; Gu, Sung-Bon [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

    1999-12-01

    (1) Development of a complete geophysical database system under C/S environment for data management. (2) Development of database system for the general user, who has not special knowledge of database, under the Internet environment. (3) Operation of the Web service for the general user. (4) Development of the stand-alone database system for a small-scale research group such as college and engineering consultant firms. (author). 15 refs.

  5. Geophysical logging of the Harwell boreholes

    International Nuclear Information System (INIS)

    Brightman, M.A.

    1983-08-01

    A comprehensive geophysical borehole logging survey was carried out on each of three deep boreholes drilled at the Harwell research site. KOALA and PETRA computer programs were used to analyse and interpret the logs to obtain continuous quantitative estimates of the geological and hydrogeological properties of the sequences penetrated at the Harwell site. Quantitative estimates of the mineral composition and porosity of the cores samples were made. (UK)

  6. Coal quality estimation using the geophysical logging of natural gamma and resistivity; Estimativa de qualidade de carvao por meio de perfilagem geofisica de gama natural e resistividade

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vladia de; Salvadoretti, Paulo; Costa, Joao Felipe Coimbra Leite; Beretta, Filipe; Koppe, Jair Carlos, E-mail: vladiasouza@gmail.co, E-mail: psalvadoretti@ufrgs.b, E-mail: jfelipe@ufrgs.b, E-mail: fberetta@ymail.co, E-mail: jkoppe@ufrgs.b [Universidade Federal do Rio Grande do Sul (UFRGS/LPM/DEMIN), Porto Alegre, RS (Brazil). Dept. de Engenharia de Minas. Lab. de Pesquisa Mineral e Planejamento Mineiro; Bastiani, Gustavo Antonio; Carvalho Junior, Jose Adolfo; Grigorieff, Alexandre, E-mail: gustavo.bastiani@terra.com.b, E-mail: adolfo@copelmi.com.b, E-mail: alex@copelmi.com.b [COPELMI Mineracao, Porto Alegre, RS (Brazil)

    2010-10-15

    This study investigates geophysical logging as a tool to predict coal quality. Some of the coal's chemical parameters were determined by laboratory analysis and were compared against values derived from geophysical logging correlation (natural gamma radiation and resistivity versus ash content, specifically). The results showed a strong correlation between the coal's natural gamma emissions and their ash content. From this correlation, a simple linear model was obtained and used to estimate ash grades, directly from geophysical logging records. The error of these predictions is less than {+-} 5%. Additionally, results showed no correlation between the sulphur grade, or volatile matter, and the geophysical records. Ash grades derived from natural gamma ray values can be used as secondary information to evaluate coal quality during resource estimation, when combined with lab analysis and appropriate geostatistical methods. The methodology is illustrated by means of a case study at a coal deposit located in Southern Brazil. (author)

  7. Integrated geophysical study of the northeastern margin of Tibetan Plateau

    Science.gov (United States)

    Shi, L.; Meng, X.; Guo, L.

    2011-12-01

    Tibetan Plateau, the so-called "Roof of the World", is a direct consequence of collision of the Indian plate with the Eurasian plate starting in the early Cenozoic time. The continent-continent collision is still going on. The northeastern margin of Tibetan Plateau is the front part of the Tibetan Plateau extends to mainland and favorable area for studying uplift and deformation of the Tibetan Plateau. In the past decades, a variety of geophysical methods were conducted to study geodynamics and geological tectonics of this region. We assembled satellite-derived free-air gravity anomalies with a resolution of one arc-minute from the Scripps Institution of Oceanography, and reduced them to obtain Complete Bouguer Gravity Anomalies. Then we gridded Complete Bouguer Gravity Anomalies on a regular grid, and subsequently processed them with the preferential continuation method to attenuate high-frequency noise and analyzed regional and residual anomalies. We also calculated tilt-angle derivative of Complete Bouguer Gravity Anomalies to derive clearer geological structures with more details. Then we calculated the depth distribution of the Moho discontinuity surface in this area by 3D density interface inversion. From the results of preliminary processing, we analyzed the main deep faults and geological tectonics in this region. We extracted seven important profiles' data of Complete Bouguer Gravity Anomalies in this area, and then did forward modeling and inversion on each profile with constraints of geological information and other geophysical data. In the future, we will perform 3D constrained inversion of Complete Bouguer Gravity Anomalies in this region for better understanding deep structure and tectonics of the northeastern margin of Tibetan Plateau. Acknowledgment: We acknowledge the financial support of the SinoProbe project (201011039), the Fundamental Research Funds for the Central Universities (2010ZY26 2011PY0184), and the National Natural Science Foundation

  8. Geophysical prospecting in archaeology: investigations in Santa Venera, south suburb of Poseidonia-Paestum, Campania, southern Italy

    International Nuclear Information System (INIS)

    Loperte, A; Satriani, A; Bavusi, M; Lapenna, V; Del Lungo, S; Gizzi, F T; Sabelli, R

    2011-01-01

    This paper is the result of a joint work between geophysicists and archaeologists in which the authors have used geophysical techniques to investigate the Greek and Roman settlement of Paestum, southern Italy for preventive archaeological research (commonly termed 'rescue archaeology') on an area of the ancient settlement affected by new building work and infrastructure. Starting from a background analysis of the archaeological and geological features of the site, an integrated geophysical approach based on magnetic, GPR and geoelectrical surveys was carried out on the Santa Venera area, a site selected to build a car parking. High-density and high-resolution cross-correlated geophysical surveys were carried out in different parts of the area to better resolve the structures. Systematic excavations confirmed the clues suggested by geophysical prospecting about the presence of archaeological remains such as walls, canals and tombs. By the use of non-destructive geophysical techniques a two-fold aim was reached: to properly plan the building of the infrastructure and preserve the ancient artefacts according to the advanced European guidelines on the protection of archaeological heritage

  9. Geophysical investigation of the ''Thimble,'' 100-H Area

    International Nuclear Information System (INIS)

    Bergstrom, K.A.

    1994-01-01

    This report summarizes the results of the geophysical investigations conducted as part of the characterization of the buried ''Thimble'' site. The site is located just south of the 116-H-2 Crib and is in the 100-HR-2 Operable Unit. Available documentation has it located between, and at the convergence of, two railroad spurs that run north-south. A concrete monument is believed to mark the site. The burial ground is suspected of containing a vertical safety rod thimble that is reportedly 40 ft long. Ground-penetrating radar (GPR) and electromagnetic induction (EMI) were the two techniques used in the investigation. The methods were selected because they are non-intrusive, relatively fast, economical, and have been used successfully in other similar investigations on the Hanford Site. The objective of the investigation was to locate the buried thimble

  10. 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.

  11. Ground geophysical study of the Buckeye mine tailings, Boulder watershed, Montana

    Science.gov (United States)

    McDougal, Robert R.; Smith, Bruce D.

    2000-01-01

    The Buckeye mine site is located in the Boulder River watershed along Basin Creek, in northern Jefferson County, Montana. This project is part of the Boulder River watershed Abandoned Mine Lands Initiative, and is a collaborative effort between the U.S. Geological Survey and Bureau of Land Management in the U.S. Department of the Interior, and the U.S. Forest Service in the U.S. Department of Agriculture. The site includes a large flotation milltailing deposit, which extends to the stream and meadows below the mine. These tailings contain elevated levels of metals, such as silver, cadmium, copper, lead, and zinc. Metal-rich fluvial tailings containing these metals, are possible sources of ground and surface water contamination. Geophysical methods were used to characterize the sediments at the Buckeye mine site. Ground geophysical surveys, including electromagnetics, DC resistivity, and total field magnetic methods, were used to delineate anomalies that probably correlate with subsurface metal contamination. Subsurface conductivity was mapped using EM-31 and EM-34 terrain conductivity measuring systems. The conductivity maps represent variation of concentration of dissolved solids in the subsurface from a few meters, to an approximate depth of 30 meters. Conductive sulfides several centimeters thick were encountered in a shallow trench, dug in an area of very high conductivity, at a depth of approximately 1 to1.5 meters. Laboratory measurements of samples of the sulfide layers show the conductivity is on the order of 1000 millisiemens. DC resistivity soundings were used to quantify subsurface conductivity variations and to estimate the depth to bedrock. Total field magnetic measurements were used to identify magnetic metals in the subsurface. The EM surveys identified several areas of relatively high conductivity and detected a conductive plume extending to the southwest, toward the stream. This plume correlates well with the potentiometric surface and direction of

  12. 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...

  13. Atmospheric and Geophysical Sciences Program report, 1990--1991

    International Nuclear Information System (INIS)

    MacCracken, M.C.; Albritton, J.R.; MacGregor, P.M.

    1992-06-01

    This report describes research programs from Lawrence Livermore Laboratory from 1990--1991 in atmospheric chemistry and geophysics. Programs such as mathematical modeling of atmospheric dispersions of pollutants and radionuclides,tropospheric chemistry, clouds, climate models, and the effects of atmospheric trace constiuents on ozone are described

  14. Shallow Depth Geophysical Investigation Through the Application of Magnetic and Electric Resistance Techniques: AN Evaluation Study of the Responses of Magnetic and Electric Resistance Techniques to Archaeogeophysical Prospection Surveys in Greece and Cyprus

    Science.gov (United States)

    Sarris, Apostolos

    The response characteristics of total intensity and vertical gradient magnetic techniques have been investigated in detail and compared with electric resistivity and other geophysical techniques. Four case studies from archaeological sites of Greece and Cyprus have been used as the experimental basis of this research project. Data from shallow depth geophysical investigations in these sites were collected over a period of four years. Interpretation of the geophysical results was based on the integration of the various prospecting methods. The results of the comparative study between the different techniques showed a strong correlation among all methods allowing the detection of certain features and the determination of their dimensions. The application of a large range of geophysical prospecting techniques in the surveyed archaeological sites has been able to detect the approximate position of the subsurface remains and to compare the different techniques in terms of the information that they reveal. Each one of these techniques has been used to examine the characteristic response of each method to the geophysical anomalies associated with the surveyed sites. Magnetic susceptibility measurements at two frequencies have identified areas and levels of intense human activity. A number of processing techniques such as low, high and band pass filtering in the spatial and frequency domain, computation of the residuals and fast Fourier transformation (FFT) of the magnetic potential data have been applied to the geophysical measurements. The subsequent convolution with filters representing apparent susceptibility, reduction to pole and equator, Gaussian and Butterworth regional and residual distributions, and inverse filtering in terms of spiking deconvolution have revealed a wealth of information necessary to obtain a more accurate picture of the concealed features. Inverse modelling of isolated magnetic anomalies has further enriched the information database of the

  15. Geophysical Responses of Hydrocarbon-impacted Zones at the Various Contamination Conditions

    Science.gov (United States)

    Kim, C.; Ko, K.; Son, J.; Kim, J.

    2008-12-01

    aged LNAPL- impacted sites, and (3) high electrical resistivity anomalies at the fresh or aged sites contaminated with residual products of crude oils (lubricating oils). The study results also show that the geophysical methods, as a non-invasive sounding technique, can be effectively applied to mapping hydrocarbon-contaminated zones.

  16. The Chinese Cretaceous Continental Scientific Drilling Project in the Songliao Basin, NE China: Organic-rich source rock evaluation with geophysical logs from Borehole SK-2

    Science.gov (United States)

    Zhang, X.; Zou, C.

    2017-12-01

    The Cretaceous strata have been recognized as an important target of oil or gas exploration in the Songliao Basin, northeast China. The second borehole (SK-2) of the Chinese Cretaceous Continental Scientific Drilling Project in the Songliao Basin (CCSD-SK) is the first one to drill through the Cretaceous continental strata in the frame of ICDP. It was designed not only to solve multiple scientific problems (including the Cretaceous paleoenvironment and paleoclimate, as well as deep resources exploration of the Songliao Basin), but also to expect to achieve new breakthroughs in oil and gas exploration. Based on the project, various geophysical log data (including gamma, sonic, resistivity, density etc.) and core samples have been collected from Borehole SK-2. We do research on organic-rich source rocks estimation using various geophysical log data. Firstly, we comprehensively analyzed organic-rich source rocks' geophysical log response characteristics. Then, source rock's identification methods were constructed to identify organic-rich source rocks with geophysical logs. The main identification methods include cross-plot, multiple overlap and Decision Tree method. Finally, the technique and the CARBOLOG method were applied to evaluate total organic carbon (TOC) content from geophysical logs which provide continuous vertical profile estimations (Passey, 1990; Carpentier et al., 1991). The results show that source rocks are widely distributed in Borehole SK-2, over a large depth strata (985 5700m), including Nenjiang, Qingshankou, Denglouku, Yingcheng, Shahezi Formations. The organic-rich source rocks with higher TOC content occur in the Qingshankou (1647 1650m), Denglouku (2534 2887m) and Shahezi (3367 5697m) Formations. The highest TOC content in these formations can reach 10.31%, 6.58%, 12.79% respectively. The bed thickness of organic-rich source rocks in the these formations are totally up to 7.88m, 74.34m, 276.60m respectively. These organic-rich rocks in the

  17. A Modular Environment for Geophysical Inversion and Run-time Autotuning using Heterogeneous Computing Systems

    Science.gov (United States)

    Myre, Joseph M.

    Heterogeneous computing systems have recently come to the forefront of the High-Performance Computing (HPC) community's interest. HPC computer systems that incorporate special purpose accelerators, such as Graphics Processing Units (GPUs), are said to be heterogeneous. Large scale heterogeneous computing systems have consistently ranked highly on the Top500 list since the beginning of the heterogeneous computing trend. By using heterogeneous computing systems that consist of both general purpose processors and special- purpose accelerators, the speed and problem size of many simulations could be dramatically increased. Ultimately this results in enhanced simulation capabilities that allows, in some cases for the first time, the execution of parameter space and uncertainty analyses, model optimizations, and other inverse modeling techniques that are critical for scientific discovery and engineering analysis. However, simplifying the usage and optimization of codes for heterogeneous computing systems remains a challenge. This is particularly true for scientists and engineers for whom understanding HPC architectures and undertaking performance analysis may not be primary research objectives. To enable scientists and engineers to remain focused on their primary research objectives, a modular environment for geophysical inversion and run-time autotuning on heterogeneous computing systems is presented. This environment is composed of three major components: 1) CUSH---a framework for reducing the complexity of programming heterogeneous computer systems, 2) geophysical inversion routines which can be used to characterize physical systems, and 3) run-time autotuning routines designed to determine configurations of heterogeneous computing systems in an attempt to maximize the performance of scientific and engineering codes. Using three case studies, a lattice-Boltzmann method, a non-negative least squares inversion, and a finite-difference fluid flow method, it is shown that

  18. Geophysical Characterization of the Quaternary-Cretaceous Contact Using Surface Resistivity Methods in Franklin and Webster Counties, South-Central Nebraska

    Science.gov (United States)

    Teeple, Andrew; Kress, Wade H.; Cannia, James C.; Ball, Lyndsay B.

    2009-01-01

    To help manage and understand the Platte River system in Nebraska, the Platte River Cooperative Hydrology Study (COHYST), a group of state and local governmental agencies, developed a regional ground-water model. The southern boundary of this model lies along the Republican River, where an area with insufficient geologic data immediately north of the Republican River led to problems in the conceptualization of the simulated flow system and to potential problems with calibration of the simulation. Geologic descriptions from a group of test holes drilled in south-central Nebraska during 2001 and 2002 indicated a possible hydrologic disconnection between the Quaternary-age alluvial deposits in the uplands and those in the Republican River lowland. This disconnection was observed near a topographic high in the Cretaceous-age Niobrara Formation, which is the local bedrock. In 2003, the U.S. Geological Survey, in cooperation with the COHYST, collected surface geophysical data near these test holes to better define this discontinuity. Two-dimensional imaging methods for direct-current resistivity and capacitively coupled resistivity were used to define the subsurface distribution of resistivity along several county roads near Riverton and Inavale, Nebraska. The relation between the subsurface distribution of resistivity and geology was defined by comparing existing geologic descriptions of test holes to surface-geophysical resistivity data along two profiles and using the information gained from these comparisons to interpret the remaining four profiles. In all of the resistivity profile sections, there was generally a three-layer subsurface interpretation, with a resistor located between two conductors. Further comparison of geologic data with the geophysical data and with surficial features was used to identify a topographic high in the Niobrara Formation near the Franklin Canal which was coincident with a resistivity high. Electrical properties of the Niobrara

  19. Joint inversion of geophysical data for site characterization and restoration monitoring. FY97 annual progress report for EMSP

    International Nuclear Information System (INIS)

    Berge, P.A.; Berryman, J.G.; Bonner, B.P.; Roberts, J.J.; Wildenschild

    1997-01-01

    'The purpose of this project is to develop a computer code for joint in-version 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 under-ground imaging, since interpretation of data collected at a contaminated site would become much less subjective. The schedule of this project is as follows: In the first year, investigators perform laboratory measurements of elastic and electrical properties of sand-clay mixtures containing various fluids. Investigators also develop methods of relating measurable geophysical properties to porosity and saturation by using rock physics theories, geostatistical, and empirical techniques together with available laboratory measurements. In the second year, investigators finish any necessary laboratory measurements and apply the methods developed in the first year to invert available borehole log data to predict measured properties of cores and sediments from a borehole. Investigators refine the inversion code in the third year and carry out a field experiment to collect seismic and electrical data. Investigators then use the inversion code to invert the field data to produce estimates of porosity and saturation in the field area where the data were collected. This report describes progress made in the first year of this three-year project.'

  20. Record of the Solar Activity and of Other Geophysical Phenomenons in Tree Ring

    Science.gov (United States)

    Rigozo, Nivaor Rodolfo

    1999-01-01

    Tree ring studies are usually used to determine or verify climatic factors which prevail in a given place or region and may cause tree ring width variations. Few studies are dedicated to the geophysical phenomena which may underlie these tree ring width variations. In order to look for periodicities which may be associated to the solar activity and/or to other geophysical phenomena which may influence tree ring growth, a new interactive image analysis method to measure tree ring width was developed and is presented here. This method makes use of a computer and a high resolution flatbed scanner; a program was also developed in Interactive Data Language (IDL 5.0) to study ring digitized images and transform them into time series. The main advantage of this method is the tree ring image interactive analysis without needing complex and high cost instrumentation. Thirty-nine samples were collected: 12 from Concordia - S. C., 9 from Canela - R. S., 14 from Sao Francisco de Paula - R. S., one from Nova Petropolis - R. S., 2 from Sao Martinho da Serra - R. S. e one from Chile. Fit functions are applied to ring width time series to obtain the best long time range trend (growth rate of every tree) curves and are eliminated through a standardization process that gives the tree ring index time series from which is performed spectral analysis by maximum entropy method and iterative regression. The results obtained show periodicities close to 11 yr, 22 yr Hale solar cycles and 5.5 yr for all sampling locations 52 yr and Gleissberg cycles for Concordia - S. C. and Chile samples. El Nino events were also observed with periods around 4 e 7 yr.