Science.gov

Sample records for addition geophysical surveys

  1. A positioning and data logging system for surface geophysical surveys

    SciTech Connect

    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.

  2. Geophysical survey at Tell Barri (Syria)

    NASA Astrophysics Data System (ADS)

    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

  3. Geophysical surveys for monitoring coastal salt water intrusion

    NASA Astrophysics Data System (ADS)

    Loperte, A.; Satriani, A.; Simoniello, T.; Imbrenda, V.; Lapenna, V.

    2009-04-01

    Geophysical surveys have been exploited in a coastal forest reserve, at the mouth of the river Bradano in South Italy (Basilicata, southern Italy, N 40°22', E 16°51'), to investigate the subsurface saltwater contamination. Forest Reserve of Metapontum is a wood of artificial formation planted to protect fruit and vegetable cultivations from salt sea-wind; in particular it is constituted by a back dune pine forest mainly composed of Aleppo Pine trees (Pinus halepensis) and domestic pine trees (Pinus pinea). Two separate geophysical field campaigns, one executed in 2006 and a second executed in 2008, were performed in the forest reserve; in particular, electrical resistivity tomographies, resistivity and ground penetrating radar maps were elaborated and analyzed. In addition, chemical and physical analyses on soil and waters samples were performed in order to confirm and integrate geophysical data. The analyses carried out allowed an accurate characterization of salt intrusion phenomenon: the spatial extension and depth of the saline wedge were estimated. Primary and secondary salinity of the Metapontum forest reserve soil occurred because of high water-table and the evapo-transpiration rate which was much higher than the rainfall rate; these, of course, are linked to natural factors such as climate, natural drainage patterns, topographic features, geological structure and distance to the sea. Naturally, since poor land management, like the construction of river dams, indiscriminate extraction of inert from riverbeds that subtract supplies sedimentary, the alteration of the natural water balance, plays an important role in this process. The obtained results highlighted that integrated geophysical surveys gave a precious contribute for better evaluating marine intrusion wedge in coastal aquifers and providing a rapid, non-invasive and low cost tool for coastal monitoring.

  4. Airborne Geophysical Surveys Applied to Hydrocarbon Resource Development Environmental Studies

    NASA Astrophysics Data System (ADS)

    Smith, B. D.; Ball, L. B.; Finn, C.; Kass, A.; Thamke, J.

    2014-12-01

    Application of airborne geophysical surveys ranges in scale from detailed site scale such as locating abandoned well casing and saline water plumes to landscape scale for mapping hydrogeologic frameworks pertinent to ground water and tectonic settings relevant to studies of induced seismicity. These topics are important in understanding possible effects of hydrocarbon development on the environment. In addition airborne geophysical surveys can be used in establishing baseline "snapshots", to provide information in beneficial uses of produced waters, and in mapping ground water resources for use in well development. The U.S. Geological Survey (USGS) has conducted airborne geophysical surveys over more than 20 years for applications in energy resource environmental studies. A majority of these surveys are airborne electromagnetic (AEM) surveys to map subsurface electrical conductivity related to plumes of saline waters and more recently to map hydrogeologic frameworks for ground water and plume migration. AEM surveys have been used in the Powder River Basin of Wyoming to characterize the near surface geologic framework for siting produced water disposal ponds and for beneficial utilization in subsurface drip irrigation. A recent AEM survey at the Fort Peck Reservation, Montana, was used to map both shallow plumes from brine pits and surface infrastructure sources and a deeper concealed saline water plume from a failed injection well. Other reported applications have been to map areas geologically favorable for shallow gas that could influence drilling location and design. Airborne magnetic methods have been used to image the location of undocumented abandoned well casings which can serve as conduits to the near surface for coproduced waters. They have also been used in conjunction with geologic framework studies to understand the possible relationships between tectonic features and induced earthquakes in the Raton Basin. Airborne gravity as well as developing deeper

  5. Geophysical surveys around the Izmir Bay

    NASA Astrophysics Data System (ADS)

    Aykut, Tunçel; Tolga, Gönenç; Mustafa, Akgün; Oya, Pamukcu; Özkan, Özdağ; Mehmet, Çetiner

    2015-04-01

    amplification, can be expected that will cause negative effect on behavior of constructions during earthquake. In this context, in order to investigate the actual size of the danger which can be caused by soil deformations according to ground motion, TUBITAK projects were generated at Izmir and its vicinity. Goals of the projects were defined as investigating the bedrock, highlighting of dynamic parameters of soil structures and determination of basin geometry. In accordance with these objectives, geophysical surveys funded by TUBITAK were implemented. In this study, seven areas of Izmir where geophysical surveys were conducted will be presented. ACKNOWLEDGMENTS This study has been achieved under the scope of The Scientific and Technological Research Council of Turkey (TUBITAK) projects (106G159 and 108Y285). Key words: Izmir soil, microgravity, microtremor, MASW, SPAC

  6. Payload-Directed Control of Geophysical Magnetic Surveys

    NASA Technical Reports Server (NTRS)

    Lee, Ritchie; Yeh, Yoo-Hsiu; Ippolito, Corey; Spritzer, John; Phelps, Geoffrey

    2010-01-01

    Using non-navigational (e.g. imagers, scientific) sensor information in control loops is a difficult problem to which no general solution exists. Whether the task can be successfully achieved in a particular case depends highly on problem specifics, such as application domain and sensors of interest. In this study, we investigate the feasibility of using magnetometer data for control feedback in the context of geophysical magnetic surveys. An experimental system was created and deployed to (a) assess sensor integration with autonomous vehicles, (b) investigate how magnetometer data can be used for feedback control, and (c) evaluate the feasibility of using such a system for geophysical magnetic surveys. Finally, we report the results of our experiments and show that payload-directed control of geophysical magnetic surveys is indeed feasible.

  7. Airborne geophysical surveys conducted in western Nebraska, 2010: contractor reports and data

    USGS Publications Warehouse

    ,

    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.

  8. Aerial remote sensing surveys, geophysical characterization. Final report

    SciTech Connect

    Labson, V.F.; Pellerin, L.; Anderson, W.L.

    1998-06-01

    The application of helicopter electromagnetic (HEM) and magnetic methods to the requirements of the environmental restoration of the Oak Ridge Reservation (ORR) demand the use of advanced, nontraditional methods of data acquisition, processing and interpretation. The cooperative study by the U.S. Geological Survey (USGS), Oak Ridge National Laboratory (ORNL), and University of California (UCB) has resulted in the planning and supervision of data acquisition, the development of tools for data processing and interpretation, and an intensive application of the methods developed. This final report consists of a series of publications which the USGS collaborated with the ORNL technical staff. These reports represent the full scope of the USGS assistance. Copies of the reports and papers are included in the Appendix. The primary goals of this effort were to quantify the effectiveness of the geophysical methods applied in the survey of the ORR for the identification of buried waste, hydrogeologic pathways by which contamination could migrate through or off the site, and for the more accurate geologic mapping of the ORR. The objectives in buried waste identification are the accurate description of the source of the geophysical anomaly and the determination of the limits of resolution of the geophysical methods to acknowledge what we might have missed. The study of hydrogeologic pathways concentrated on the identification of karst features in the limestone underlying much of the ORR. Work in this study has indicated to the ORNL staff that these karst features can be located from the airborne geophysics. The defining characteristic of this helicopter geophysical study is the collaborative nature of the effort. Each task in which the USGS was involved has included a designated staff member from the Oak Ridge National Laboratory.

  9. Multiple geophysical surveys for old landfill monitoring in Singapore.

    PubMed

    Yin, Ke; Tong, Huanhuan; Giannis, Apostolos; Wang, Jing-Yuan; Chang, Victor W-C

    2017-01-01

    One-dimensional boring presents limitations on mapping the refuse profile in old landfills owning to waste heterogeneity. Electrical imaging (EI) and multiple-analysis of surface wave (MASW) were hereby deployed at an old dumping ground in Singapore to explore the subsurface in relation to geotechnical analysis. MASW estimated the refuse boundary with a higher precision as compared to EI, due to its endurance for moisture variation. EI and MASW transection profiles suggested spots of interest, e.g., refuse pockets and leachate mounds. 3D inversion of EI and MASW data further illustrated the transformation dynamics derived by natural attenuation, for instance the preferential infiltration pathway. Comparison of geophysical surveys at different years uncovered the subterranean landfill conditions, indicating strong impacts induced by aging, precipitation, and settlement. This study may shed light on a characterization framework of old landfills via combined geophysical models, thriving landfill knowledge with a higher creditability.

  10. Geophysical survey of the Burnum archaeological site (Croatia)

    NASA Astrophysics Data System (ADS)

    Boschi, Federica; Campedelli, Alessandro; Giorgi, Enrico; Lepore, Giuseppe; de Maria, Sandro

    2010-05-01

    A multidisciplinary geophysical investigation has been carried out at the site of Burnum (Krka Valley, Croatia) by the University of Bologna, in the context of an international agreement between the University of Zadar, the Civic Museum of Drniš, and the Centre for the Study of the Adriatic Sea Archaeology (Ravenna). The Burnum Project aims at improving our knowledge and preserve the important roman castrum, transformed in a municipium at the beginning of the 2nd century AD. Since 2005, different geophysical techniques have been applied to the site, such as magnetometry, electrical resistivity studies and ground penetrating radar, making the investigated area an interesting case history of a multidisciplinary approach applied to archaeology. After different field works, the geophysical mapping of the southern part of the castrum is almost complete, whereas the northern one will be completed during next planned campaigns. Magnetic data have been collected with the gradient technique, using an Overhauser system and an optically-pumped Potassium magnetometer-gradiometer, configured with a vertical sensor distance of 1.50 m. The resistivity method has been applied using the ARP© (Automatic Resistivity Profiling) and the OhM Mapper systems. GPR surveys have been carried out testing different systems and antennas. During 2009, a special emphasis was given to the acquisition, processing and interpretation of the optically-pumped Potassium magnetometer-gradiometer data. As a result, a clear image of the settlement configuration was obtained, improving our knowledge of the forum-basilica complex and possibly discovering a second auxiliary castrum. Direct exploration by archaeological excavations of selected areas has correctly confirmed the geophysical results and the archaeological interpretation proposed. The features of the building materials, brought to the light and analysed after the excavations, were coherent with the instrumental responses of all the applied

  11. Geophysical surveys and archaeological insights at Fort Pierre Chouteau, a frontier trading post on the Middle Missouri

    NASA Astrophysics Data System (ADS)

    Patton, Margaret Maurine

    Fort Pierre Chouteau in present day South Dakota was the most important fur trading post of the American Fur Company in the 1830s, serving as a regional hub for the fur trade. The Fort was sold to the U.S. Military in 1855 for use as a base in the Sioux Wars but was abandoned in 1856. Geophysical surveys and previous excavations indicate evidence of both occupations. Geophysics is an important tool for determining the extent of archaeological sites, yet the relationships between geophysical anomalies and excavation features may not be readily evident. Initial geophysical surveys (Kvamme 2007) were completed to determine the extent of the fur trading Fort, and additional surveys in August 2012 used magnetometry and electrical resistance to determine if evidence of military structures exists outside of the Fort. This study examines connections between excavation features and geophysical anomalies in order to better interpret anomalies inside the Fort palisade. The palisade builder's trench, adobe pavement, post holes, and unknown structures are characterized through the analysis of the excavations and anomalies. The location of one of the military structures outside of the palisade is also identified. As many sites have histories of excavations prior to any geophysical surveys, combining the two sets of information is important in order to more fully understand site layout and the archaeological causes of geophysical anomalies.

  12. Geophysical Surveys for Detecting Distribution and Shape of Ice Wedges

    NASA Astrophysics Data System (ADS)

    Watanabe, T.; Matsuoka, N.; Ikeda, A.

    2006-12-01

    Recent development of applied geophysical methods has shown detailed structure in various periglacial features. However, these methods have been rarely applied to studies in ice wedges. Thus, we attempted to display distribution and shape of ice wedges using a ground penetrating radar (GPR) and a direct current (DC) resistivity meter. The surveys were performed at a comprehensive monitoring site of ice-wedging in Adventdalen, Svalbard, where troughs and small cracks form polygonal patterns on the ground. Unknown structure below such new cracks is also focused in this study. We obtained 37 GPR profiles using 250 MHz signal. 2-D resistivity surveys were also performed along 14 GPR profiles. The electrodes were placed at 1 m intervals and their combination followed the Wenner array. In addition, shallow boreholes were dug across 5 troughs/cracks to estimate the width of ice wedge. The analyzed results show parabolic patterns formed by the multiple radar waveforms and largely increasing gradients of DC resistivity below the troughs and small cracks. The strong reflections of the radar signals and the starting zones of the increasing resistivity lay about 1 m deep, which corresponded to the top of ice wedges (0.7-0.9 m deep) revealed by the drilling. In the GPR profiles, a relatively flat pattern of the reflection was sandwiched by a pair of parabolic patterns below each well-developed trough, whereas a sharp parabolic pattern was detected below each small crack. These results mean that the presence of narrow ice wedges is detectable by the GPR method and the top of a parabolic pattern roughly corresponds to one edge of an ice wedge table. In the DC resistivity profiles, a high resistivity core exists below each trough and crack. The high resistivity probably resulted from ice having lower unfrozen water content than the surrounding silt materials. The heights of the cores indicate that the ice wedges were formed at least between 1 m and 3 m deep. The cores are, however

  13. Airborne geophysical surveys over the eastern Adirondacks, New York State

    USGS Publications Warehouse

    Shah, Anjana K.

    2016-01-01

    Airborne geophysical surveys were conducted in the eastern Adirondacks from Dec. 7, 2015 - Dec. 21, 2015, by Goldak Airborne Surveys. The area was flown along a draped surface with a nominal survey height above ground of 200 meters. The flight line spacing was 250 meters for traverse lines and 2500 meters for control lines. Here we present downloadable magnetic and radiometric (gamma spectrometry) data from those surveys as image (Geotiff) and flight line data (csv format).BackgroundThe Eastern Adirondacks region was known for iron mining in the 1800's and 1900's but it also contains deposits of rare earth minerals. Rare earth minerals are used in advanced technology such as in cell phones, rechargeable batteries and super-magnets. In many areas rare earth minerals appear to be associated with iron ore.The surveys were flown in order to map geologic variations in three dimensions. Magnetic surveys measure subtle changes in Earth's magnetic field that reflect different types of buried rock, such as iron-rich ore bodies. Radiometric methods detect naturally occurring gamma particles. The energy spectra of these particles can be used to estimate relative amounts of potassium, uranium and thorium (also referred to as gamma ray spectrometry), which are sometimes associated with rare earth elements. Together, these data provide insights into the regional tectonic and magmatic history as well as mineral resources in the area.

  14. Geophysics

    NASA Technical Reports Server (NTRS)

    Carr, M. H.; Cassen, P.

    1976-01-01

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

  15. Alternative analysis of airborne laser data collected within conventional multi-parameter airborne geophysical surveys

    NASA Astrophysics Data System (ADS)

    Ahl, Andreas; Supper, R.; Motschka, K.; Schattauer, I.

    2010-05-01

    For the interpretation of airborne gamma-ray spectrometry as well as airborne electromagnetics it is of great importance to determine the distance between the geophysical sensor and the ground surface. Since radar altimeters do not penetrate vegetation, laser altimeters became popular in airborne geophysics over the past years. Currently the airborne geophysical platform of the Geological Survey of Austria (GBA) is equipped with a Riegl LD90-3800VHS-FLP high resolution laser altimeter, measuring the distances according to the first and the last reflected pulse. The goal of the presented study was to explore the possibilities of deriving additional information about the survey area from the laser data and to determine the accuracy of such results. On one hand the difference between the arrival time of the first and the last reflected pulse can be used to determine the height of the vegetation. This parameter is for example important for the correction of damping effects on airborne gamma-ray measurements caused by vegetation. Moreover especially for groundwater studies at catchment scale, this parameter can also be applied to support the spatial assessment of evapotranspiration. In combination with the altitude above geoid, determined by a GPS receiver, a rough digital elevation model of the survey area can be derived from the laser altimetry. Based on a data set from a survey area in the northern part of Austria, close to the border with the Czech Republic, the reliability of such a digital elevation model and the calculated vegetation height was tested. In this study a mean deviation of -1.4m, with a standard deviation of ±3.4m, between the digital elevation model from Upper Austria (25m spatial resolution) and the determined elevation model was determined. We also found an obvious correlation between the calculated vegetation heights greater 15m and the mapped forest published by the ‘Department of Forest Inventory' of the ‘Federal Forest Office' of Austria

  16. Geophysical survey of 105-DR Pluto Crib, 116-DR-4, 100-D Area

    SciTech Connect

    Bergstrom, K.A.

    1993-10-01

    The objective of this Geophysical Survey was to verify the location of the 105-DR Pluto Crib, 116-DR-4. A surface monument currently marks its location. The crib is 10 feet by 10 feet and 15 feet deep. Ground-Penetrating Radar was the geophysical method selected to conduct the investigation.

  17. Marine Geophysical Surveying Along the Hubbard Glacier Terminus, Southeast Alaska

    NASA Astrophysics Data System (ADS)

    Goff, J. A.; Davis, M.; Gulick, S. P.; Lawson, D. E.; Willems, B. A.

    2010-12-01

    Tidewater glaciers are a challenging environment for marine investigations, owing to the dangers associated with calving and restrictions on operations due to dense floating ice. We report here on recent efforts to conduct marine geophysical surveys proximal to the ice face of Hubbard Glacier, in Disenchantment Bay, Alaska. Hubbard is an advancing tidewater glacier that has twice recently (1986 and 2002) impinged on Gilbert Point, which separates Russell Fiord from Disenchantment Bay, thereby temporarily creating a glacially-dammed Russell Lake. Continued advance will likely form a more permanent dam, rerouting brackish outflow waters into the Situk River, near Yakutat, Alaska. Our primary interest is in studying the development and motion of the morainal bank which, for an advancing tidewater glacier, stabilizes it against rapid retreat. For survey work, we operated with a small, fast, aluminum-hulled vessel and a captain experienced in operating in ice-bound conditions, providing a high margin of safety and maneuverability. Differencing of multibeam bathymetric data acquired in different years can identify and quantify areas of deposition and erosion on the morainal bank front and in Disenchantment Bay proper, where accumulation rates are typically > 1 m/yr within 1 km of the glacier terminus. The advance or retreat rate of the morainal bank can be determined by changes in the bed elevation through time; we document advance rates that average > 30 m/yr in Disenchantment Bay, but which vary substantially over different time periods and at different positions along the ice face. Georeferencing of available satellite imagery allows us to directly compare the position of the glacial terminus with the position of the morainal bank. From 1978 to 1999, and then to 2006, the advances in terminus and morainal bank positions were closely synchronized along the length of the glacier face. In the shallower Russell Fiord side of the terminus, a sediment ridge was mapped both

  18. Geophysical Survey of Proposed Construction Site with Possible Faulting, East San Francisco Bay Hills, California

    NASA Astrophysics Data System (ADS)

    Galvin, J. L.; Deqiang, C.; Abimbola, A.; Shuler, S.; Hayashi, K.; Fox, J.; Craig, M. S.; Strayer, L. M.; Drumm, P.

    2015-12-01

    We conducted a geophysical study at a site proposed for a new dorm building prior to trenching planned as part of a separate fault investigation study. The study area was located on the south side of the CSU East Bay campus, roughly 100 - 300 m SSE of the current dorm complex. In addition to its proximity to the Hayward Fault, several smaller faults have been previously mapped within the proposed location, including the East and West Dibblee Faults. These faults are thought to represent contacts between the Leona Rhyolite and the Knoxville Formation. Data acquisition included seismic, resistivity, and GPS data collected in an effort to develop a better understanding of the geological and structural profile of this area, including the location of lithologic contacts, faults, and the thickness of soil and fill. Geophysical profiles were collected over the locations of future trenches. The survey included geophysical lines that were located coincident with two planned trenching sites, which were chosen to intersect mapped faults. Survey positions were recorded using differential GPS. Seismic refraction and MASW (multichannel analysis of surface waves) surveys were performed over two of the planned trench sites using a 48-channel seismographic system with 4.5 Hz geophones and a 10-lb sledgehammer. For one of the lines, geophones were spaced every 3 m with a total spread length of 141 m and a shot spacing of 9 m. For the second line, geophones were spaced every 4 m with a total spread length of 188 m. Shots were taken every 12 m. Resistivity surveys were also performed along one of the line locations using both a capacitively-coupled dipole (CCD) system and 48-electrode system. Geospatial data for the survey area were compiled, including 0.3 m color orthoimagery and vector line files for geologic unit boundaries and presumed fault locations. The products of this study will include the geophysical response of geologic formations, location of unit contacts and faults

  19. 75 FR 33325 - Notice of Availability of the Draft Environmental Assessment of a Marine Geophysical Survey by...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... by the U.S. Geological Survey in the Arctic Ocean, August-September 2010 AGENCY: U.S. Geological... Environmental Assessment (EA) of a Marine Geophysical Survey by the U.S. Geological Survey in the Arctic Ocean... Geophysical Survey by the U.S. Geological Survey in the Arctic Ocean, August-September 2010 within 30...

  20. Geophysical survey applied to underwater archaeology: a 19th century town submerged in Tequesquitengo Lake, Morelos, México

    NASA Astrophysics Data System (ADS)

    Galindo Dominguez, R. E.; Bandy, W. L.

    2010-12-01

    In August 2009, we conducted an underwater geophysical survey with archaeological objectives at the Tequesquitengo Lake, in Morelos, Mexico. This survey was supervised by researchers from the UNAM’s Institute of Geophysics. The main objectives were to locate and delimitate the archaeological site of a submerged town which lies at the bottom of the lake since the mid 19th century by using geophysical survey techniques. A small size vessel used for our survey was provided by the local Harbour Master, onboard which we mounted a differential GPS unit, navigation system, a dual 38 kHz/200 Khz echosounder and 200 kHz sidescan sonar system, and a marine proton magnetometer, to accomplish our objectives. A bathymetric survey of the site was carried out. And using magnetometry the archaeological site was delimitated. We acquired various sonar images of the higher structures of a church. The magnetic maps showed us some anomalies, which could be an indication of the remains of the submerged town. Additional future surveys, backed up by more research dives could definitely help us in obtaining a broad insight into the history and cultural diversity of this site.

  1. Integrated geophysical surveys for the safety evaluation of a ground subsidence zone in a small city

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Ho; Yi, Myeong-Jong; Hwang, Se-Ho; Song, Yoonho; Cho, Seong-Jun; Synn, Joong-Ho

    2007-09-01

    Ground subsidence occurred in the centre of a small city in South Korea. In order to investigate the cause of the geological hazards and to estimate the ground safety, we carried out integrated geophysical surveys comprising two-dimensional (2D) resistivity, controlled source magnetotelluric (CSMT), magnetic, ground penetrating radar, geophysical well logging and crosshole electrical resistivity tomography (ERT) surveys. Since the target area is located in the downtown area, surface geophysical methods could not be applied systematically. To understand regional geology and to facilitate the interpretation of detailed geophysical surveys in the target area, 2D resistivity, CSMT and magnetic surveys were conducted outside the downtown area. From these results, we could define the regional structure and successively infer the geologic condition in the city centre as well. Among the geophysical techniques applied for the detailed investigation in the main target area, crosshole ERT and geophysical well logging played the most important role. For the efficient ERT field work in the busiest quarter of the city, we devised a new electrode array, modified pole-dipole array, and proved that the proposed array is efficient particularly in the area where installing a remote electrode is nearly impossible. The distribution of cavities and weak zones was interpreted by careful examination of the resistivity tomograms and geophysical logging results. Based on the distribution of cavities interpreted in a 3D manner, numerical analyses of rock engineering were further carried out and geologic hazard maps were presented. Through this comprehensive approach comprising geophysics and rock engineering, shallow limestone cavities were found to be the main cause of the ground subsidence and the excessive pumping of groundwater might trigger or accelerate the geological hazard. Reinforcement works have been carried out based on the results of these geophysical and rock engineering

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

    USGS Publications Warehouse

    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.

  3. Autonomous and Remote-Controlled Airborne and Ground-Based Robotic Platforms for Adaptive Geophysical Surveying

    NASA Astrophysics Data System (ADS)

    Spritzer, J. M.; Phelps, G. A.

    2011-12-01

    Low-cost autonomous and remote-controlled robotic platforms have opened the door to precision-guided geophysical surveying. Over the past two years, the U.S. Geological Survey, Senseta, NASA Ames Research Center, and Carnegie Mellon University Silicon Valley, have developed and deployed small autonomous and remotely controlled vehicles for geophysical investigations. The purpose of this line of investigation is to 1) increase the analytical capability, resolution, and repeatability, and 2) decrease the time, and potentially the cost and map-power necessary to conduct near-surface geophysical surveys. Current technology has advanced to the point where vehicles can perform geophysical surveys autonomously, freeing the geoscientist to process and analyze the incoming data in near-real time. This has enabled geoscientists to monitor survey parameters; process, analyze and interpret the incoming data; and test geophysical models in the same field session. This new approach, termed adaptive surveying, provides the geoscientist with choices of how the remainder of the survey should be conducted. Autonomous vehicles follow pre-programmed survey paths, which can be utilized to easily repeat surveys on the same path over large areas without the operator fatigue and error that plague man-powered surveys. While initial deployments with autonomous systems required a larger field crew than a man-powered survey, over time operational experience costs and man power requirements will decrease. Using a low-cost, commercially available chassis as the base for autonomous surveying robotic systems promise to provide higher precision and efficiency than human-powered techniques. An experimental survey successfully demonstrated the adaptive techniques described. A magnetic sensor was mounted on a small rover, which autonomously drove a prescribed course designed to provide an overview of the study area. Magnetic data was relayed to the base station periodically, processed and gridded. A

  4. Helicopter electromagnetic and magnetic geophysical survey data, Swedeburg and Sprague study areas, eastern Nebraska, May 2009

    USGS Publications Warehouse

    Smith, B.D.; Abraham, J.D.; Cannia, J.C.; Minsley, B.J.; Ball, L.B.; Steele, G.V.; Deszcz-Pan, M.

    2011-01-01

    This report is a release of digital data from a helicopter electromagnetic and magnetic survey conducted by Fugro Airborne Surveys in areas of eastern Nebraska as part of a joint hydrologic study by the Lower Platte North and Lower Platte South Natural Resources Districts, and the U.S. Geological Survey. The survey flight lines covered 1,418.6 line km (882 line mile). The survey was flown from April 22 to May 2, 2009. The objective of the contracted survey was to improve the understanding of the relation between surface water and groundwater systems critical to developing groundwater models used in management programs for water resources. The electromagnetic equipment consisted of six different coil-pair orientations that measured resistivity at separate frequencies from about 400 hertz to about 140,000 hertz. The electromagnetic data were converted to georeferenced electrical resistivity grids and maps for each frequency that represent different approximate depths of investigation for each survey area. The electrical resistivity data were input into a numerical inversion to estimate resistivity variations with depth. In addition to the electromagnetic data, total field magnetic data and digital elevation data were collected. Data released in this report consist of flight line data, digital grids, digital databases of the inverted electrical resistivity with depth, and digital maps of the apparent resistivity and total magnetic field. The range of subsurface investigation is comparable to the depth of shallow aquifers. The survey areas, Swedeburg and Sprague, were chosen based on results from test flights in 2007 in eastern Nebraska and needs of local water managers. The geophysical and hydrologic information from U.S. Geological Survey studies are being used by resource managers to develop groundwater resource plans for the area.

  5. An index of geophysical well logging in Virginia by the U.S. Geological Survey

    USGS Publications Warehouse

    Mulheren, M. Patrick; Larson, J.D.; Hopkins, Herbert T.

    1982-01-01

    Geophysical logs have been obtained in more than 170 wells in Virginia by the U.S. Geological Survey since 1968. These logs include natural gamma, electric, caliper, temperature, fluid conductivity, and fluid velocity. Most of the logs are for wells in the Coastal Plain Province of eastern Virginia. Geophysical logs aid in the interpretation of properties of earth materials, including the capacity to store and transmit water in the immediate vicinity of the well bore.

  6. 78 FR 8497 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey Off the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... geophysical (seismic) survey off the central coast of California, November to December, 2012. ADDRESSES: The... incidental to conducting a marine seismic survey within the U.S. Exclusive Economic Zone of the central coast... (Langseth) and a seismic airgun array to collect seismic data as part of the Offshore Central...

  7. Surveying and Geophysical Measurements with Inertial Rotation Sensors

    DTIC Science & Technology

    1978-01-01

    measuring the annuial wobble and Chandler wobble with 0.1%~ resolution appears feasible. Otfier GeopbvsieMl Aflnlicationg meauremenimof tilt plus Verti’-al... wobble might be feasible by monitoring azimuth and astronomic latitude in geophysical observatories. FORM DD 𔃻JAN 73 1473 EDITION OF I NOV S IS...earth’s Pole of’ rotation wobbles , nutatcs, preee ,sma-.rnd wamdes(2 andtee oin aeostral by optical astrometry, lunar and artificial satellite laser

  8. 43 CFR 3836.14 - What other requirements must geological, geochemical, or geophysical surveys meet to qualify as...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... geological, geochemical, or geophysical surveys. (b) You must record the report on the surveys with BLM and... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false What other requirements must geological... Assessment Work § 3836.14 What other requirements must geological, geochemical, or geophysical surveys...

  9. Assessment of highway condition using combined geophysical surveys

    NASA Astrophysics Data System (ADS)

    Dera, Abdallah Alhadi

    Four pavement sections were investigated using ground penetrating radar (GPR) and Ultrasonic Surface Wave (USW). The objective of this research was to compare the effectiveness of two non-destructive geophysical tools, GPR and the PSPA, in assessing the condition of the pavements, composed of different construction materials. The GPR data were acquired using a 1.5 GHz antenna along five traverses spaced at two ft. intervals approximately 1000 ft. long. On the other hand, the PSPA data were acquired at the stations spaced at 1000 ft. along the five GPR traverses. Core samples were collected at each site to constrain the interpretation of the acquired geophysical data. The sites include section US 63 about three miles north of Rolla, US 54 in Camdenton County, MO 179 in Jefferson City, and HWY U in Dent County. The types of pavement in these sites were, asphalt concrete overlaying portland cement concrete (AC/PCC), and full-depth asphalt concrete (AC) pavements or full depth bituminous mix (BM). Based on the acquired and analyzed data of the GPR and PSPA, the data of both tools correlated reasonably well. The PSPA technique successfully measured the elastic modulus and the thickness of pavement and detected horizontal flaws (e.g. debonding and delaminations). Similarly, the GPR technique successfully measured the thickness of pavement and detected horizontal flaws (e.g. debonding and delaminations) within the pavement. The research demonstrated that both non-destructive geophysical tools (GPR and PSPA) are effective in assessing the condition of different types of pavement.

  10. Investigation of coastal areas in Northern Germany using airborne geophysical surveys

    NASA Astrophysics Data System (ADS)

    Miensopust, Marion; Siemon, Bernhard; Wiederhold, Helga; Steuer, Annika; Ibs-von Seht, Malte; Voß, Wolfgang; Meyer, Uwe

    2014-05-01

    Since 2000, the German Federal Institute for Geosciences and Natural Resources (BGR) carried out several airborne geophysical surveys in Northern Germany to investigate the coastal areas of the North Sea and some of the North and East Frisian Islands. Several of those surveys were conducted in cooperation with the Leibniz Institute for Applied Geophysics (LIAG). Two helicopter-borne geophysical systems were used, namely the BGR system, which collects simultaneously frequency-domain electromagnetic, magnetic and radiometric data, and the SkyTEM system, a time-domain electromagnetic system developed by the University of Aarhus. Airborne geophysical surveys enable to investigate huge areas almost completely with high lateral resolution in a relatively short time at economic cost. In general, the results can support geological and hydrogeological mapping. Of particular importance are the airborne electromagnetic results, as the surveyed parameter - the electrical conductivity - depends on both lithology and groundwater status. Therefore, they can reveal buried valleys and the distribution of sandy and clayey sediments as well as salinization zones and fresh-water occurrences. The often simultaneously recorded magnetic and radiometric data support the electromagnetic results. Lateral changes of Quaternary and Tertiary sediments (shallow source - several tens of metres) as well as evidences of the North German Basin (deep source - several kilometres) are revealed by the magnetic results. The radiometric data indicate the various mineral compositions of the soil sediments. This BGR/LIAG project aims to build up a geophysics data base (http://geophysics-database.de/) which contains all airborne geophysical data sets. However, the more significant effort is to create a reference data set as basis for monitoring climate or man-made induced changes of the salt-water/fresh-water interface at the German North Sea coast. The significance of problems for groundwater extraction

  11. Geophysical survey for cone penetrometer site, CPT-4, 200 West area

    SciTech Connect

    Mitchell, T.H.

    1993-11-01

    This report describes a geophysical survey performed at the Hanford Reservation. The objective of the survey was to locate subsurface obstructions that may affect cone penetrometer work at site CPT-4, adjacent to and west of borehole 299-W18-252, Figure 1. Based upon the results of the survey, possible ``drill sites`` within the zone, with the least likelihood of encountering identified obstructions, were identified.

  12. Geophysical Survey of an Abandoned Cemetery in Amite County, Mississippi

    NASA Astrophysics Data System (ADS)

    Nunn, J. A.

    2012-12-01

    A Ground Penetrating Radar survey was conducted as part of a forensic investigation of an abandoned cemetery in Amite County, Mississippi. Oral histories from local residents suggest the existence of a cemetery with headstones in the early 20th century. However, the headstones were removed circa 1930 so that the area could be plowed for farming. The exact number of burials and age of burials is not known. Amite county was organized in 1809 and early settlers were of English descent from Georgia, North Carolina, and South Carolina. In addition, the study area contains several Indian mounds of unknown age that were partially leveled circa 1930 for farming. The local community is interested in preserving the site, which is now in a proposed highway expansion zone, to document the history of the area. Objectives were to determine the number and locations of graves and to define the GPR characteristics that might distinguish 19th or early 20th century burials in caskets from burials in simple (or no) enclosures or Indian artifacts. A 50 m by 25 m section was selected for the GPR survey which comprised parallel east-west profiles at a 0.5 m spacing. Profiles were collected with a Sensors and Software cart-mounted bistatic unit with 200 MHz antenna and a 0.5 m antenna separation. Soils in the study area are well drained silty loams and subsurface image quality is very good. Estimated velocity for time to depth conversion is 0.07 m/ns. Records were 90 ns in length which corresponds to a depth of approximately 3.15 m. Most graves are longitudinally oriented north-south. Therefore the GPR profiles define grave width. Graves in non-migrated GPR sections are parabolic reflections. The size and shape of these reflections distinguish them from other sources (debris or roots). Many of the parabolic reflections partially overlap which is also observed in modern cemeteries with closely spaced burials. Power lines in the area produced significant noise but the parabolic curves

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

    SciTech Connect

    Walsh, Patrick; Fercho, Steven; Perkin, Doug; Martini, Brigette; Boshmann, Darrick

    2015-06-01

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

  14. Characteristics of Sounds Emitted During High-Resolution Marine Geophysical Surveys

    DTIC Science & Technology

    2016-03-24

    associated with high-resolution marine geophysical surveys performed in U.S. waters. However, data to estimate the ecological risk associated with the...acoustic emissions could present an unrecognized ecological risk if a system thought to operate above the auditory bandwidth of a particular species was...to assess the ecological risks associated with the operation of a given high-resolution survey system has not been generally available. Therefore

  15. Geophysical surveys in Parvati valley geothermal field, Kullu, India

    NASA Astrophysics Data System (ADS)

    Rakesh Kumar, S. B.; Singh, Mohan; Gupta, L.; Rao, G. V.

    1982-08-01

    Direct current resistivity surveys and shallow temperature measurements were carried out for geothermal exploration in a part of Parvati valley, goethermal field, Himachal Pradesh, India. At a few places, the Schlumberger soundings pointed to the presence of a relatively low-resistivity shallow layer, which probably represents fractured and jointed quartzite, saturated with hot/cold water. Wenner resistivity profiles indicate the presence of some possible shallow subsurface lateral hot water channels across the valley at Manikaran. Shallow temperature measurements show a good subsurface thermal anomaly near the confluence of the rivers Brahmaganga and Parvati. The results of the survey, together with other available geodata, suggest that an anomalous heat source does not lie beneath the study area. It is postulated that the meteoric water, originating at high elevations after heating as a result of circulation at depth, emerges at the surface in the Parvati valley as hot springs, after mixing in various proportions with near surface cold waters.

  16. Geophysical survey of Bear Lake, Utah-Idaho, September 2002

    USGS Publications Warehouse

    Denny, Jane F.; Colman, Steve M.

    2003-01-01

    The U.S. Geological Survey, in cooperation with researchers from several universities, has been studying the sediments of Bear Lake since 1996. The general purpose of this effort is to reconstruct past limnological conditions and regional climate on a range of timescales, from hundreds of years to hundreds of thousands of years. The objectives of the September, 2002 operations, preliminarily reported here, were (1) to compile a detailed bathymetric map of the lake using swath-mapping techniques, in order to provide baseline data for a variety of applications and studies, and (2) to complete a sidescan-sonar survey of the lake, providing a nearly complete acoustic image of the lake floor. Limited amounts of subbottom acoustic-reflection data (chirp) were also collected, along with samples of lake-floor sediments representative of different kinds of backscatter patterns.

  17. Gas Hydrate Exploration, Mid Chilean Coast; Geochemical-Geophysical Survey

    DTIC Science & Technology

    2006-12-27

    Scleractinia - - - - - - - - Nemertinea - - Mollusca Bivalvia + - + - - ++ + - + - + - Aplacophora...Caelorinchus fasciatus and three unknow species) were observed. In addition, fauna inside stones was found ( Mollusca : Leptochiton americanus

  18. Accuracies of Positioning and Geodata Using Helicopters for Geodetic and Geophysical Surveys

    NASA Astrophysics Data System (ADS)

    Bielenberg, O.; Meyer, U.; Vasterling, M.

    2010-12-01

    : Helicopters are frequently used for airborne surveys in geodesy and geophysics. The range of accuracies needed for proper data reconstruction is wide spread from some meters for airborne magnetics to centimeters for laser scanner measurements. This study lists up to date methods of online and offline positioning, discusses their accuracies that may be achieved and relates them to different geodetic as geophysical surveys in different types of terrain. The goal is to match helicopter positioning methods with the given survey task to optimize results and work efficiency. Some fundamental studies have been conducted on helicopter work during the DESIRE (Dead Sea Integrated Research) project in Israel and Jordan which have been continued in Germany. These studies include the impact of vibrations on INS, IMU and gravity meter systems as well as the choice of antenna locations on the shell of the helicopter.

  19. An electromagnetic geophysical survey of the freshwater lens of Isla de Mona, Puerto Rico

    USGS Publications Warehouse

    Richards, R.T.; Troester, J.W.; Martinez, M.I.

    1998-01-01

    An electromagnetic reconnaissance of the freshwater lens of Isla de Mona, Puerto Rico was conducted with both terrain conductivity (TC) and transient electromagnetic (TEM) surface geophysical techniques. These geophysical surveys were limited to the southern and western parts of the island because of problems with access and cultural metallic objects such as reinforced concrete roadways on the eastern part of the island. The geophysical data were supplemented with the location of a freshwater spring found by scuba divers at a depth of about 20 m below sea level along the northern coast of the island. The geophysical data suggest that the freshwater lens has a maximum thickness of 20 m in the southern half of the island. The freshwater lens is not thickest at the center of the island but nearer the southwestern edge in Quaternary deposits and the eastern edge of the island in the Tertiary carbonates. This finding indicates that the groundwater flow paths on Isla de Mona are not radially summetrical from the center of the island to the ocean. The asymmetry of the freshwater lens indicates that the differences in hydraulic conductivity are a major factor in determining the shape of the freshwater lens. The porosity of the aquifer, as determined by the geophysical data is about 33%.

  20. Tectonic map of Liberia based on geophysical and geological surveys

    USGS Publications Warehouse

    Behrendt, John Charles; Wotorson, Cletus S.

    1972-01-01

    Interpretation of the results of aeromagnetic, total-gamma radioactivity, and gravity surveys combined with geologic data for Western Liberia from White and Leo (1969) and other geologic information allows the construction of a tectonic map of Liberia. The map approximately delineates the boundaries between the Liberian (ca. 2700 m.y.) province in the northwestern two-thirds of the country, the Eburnean (ca. 2000 m.y.) province in the south-eastern one-third, and the Pan-African (ca. 550 m.y.) province in the coastal area of the northwestern two-thirds of the country. Rock follation and tectonic structural features trend northeastward in the Liberian province, east-northeastward to north-northeastward in the Eburnean province, and northwestward in the Pan-African age province. Linear residual magnetic anomailes 20-80 km wide and 200-600 gammas in amplitude and following the northeast structural trend typical of the Liberian age province cross the entire country and extend into Sierra Leone and Ivory Coast.

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

    NASA Astrophysics Data System (ADS)

    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

  2. MAGNETOMETRY, SELF-POTENTIAL, AND SEISMIC - ADDITIONAL GEOPHYSICAL METHODS HAVING POTENTIALLY SIGNIFICANT FUTURE UTILIZATION IN AGRICULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysical methods can provide important information in agricultural settings, and the use of these techniques are becoming more and more widespread. Magnetrometry, self-potential, and seismic are three geophysical methods, all of which have the potential for substantial future use in agriculture, ...

  3. Geohazard identification: the gap between the possible and reality in geophysical surveys for the engineering industry

    NASA Astrophysics Data System (ADS)

    Dyer, Julie M.

    2011-03-01

    Offshore Contractors engaged in the business of installing pipelines and subsea structures routinely rely on third party survey data to identify and assess the risk of surface and buried geohazards. In many cases, route or site survey data are supplied to a marine Contractor with the latter having little or no input to the manner in which the geophysical and geotechnical data are acquired, processed and reported. Often, the completed survey reports indicate that neither data acquisition nor the subsequent data processing were carried out with the ultimate goal of the survey or the end user in mind. This lack of focus at the survey stage can contribute to incorrect or over-optimistic assessments of geohazard risk, with serious impact on offshore installation operations as a consequence. Two case studies from the North Sea are discussed where inappropriate data processing and reporting of geophysical data had a negative impact on offshore installation operations; these are used as a basis for a more general discussion of the underlying reasons for the production of engineering survey reports which are "not-fit-for-purpose".

  4. Rejuvenating Pre-GPS era geophysical surveys using The National Map

    USGS Publications Warehouse

    Finn, Michael P.; Shoberg, Thomas G.; Stoddard, Paul

    2013-01-01

    Old geophysical surveys [pre–Global Positioning System (GPS)] stand as valuable, largely untapped sources of scientific data. If data from these surveys were in a format that had reasonable accuracy, availability, and ease of access, they could be more widely used. In this paper, a pre-GPS survey is integrated into a modern geographic database, in this case, The National Map (TNM). The ultimate goal is to improve the accuracy, precision, provenance, and ease of access of the geospatial components of archived geophysical data. An unique set of data sources was assembled for this purpose. A comparison of these different data sources indicates that more than 80% of stations were positioned on The National Map within 15 m (horizontal) and 2 m (vertical) of the GPS-derived coordinates for each station within the survey. Although online database coordinate accuracy continues to improve, these results imply that web databases have already matured to a point where it is possible to integrate pre-GPS era survey coordinate data with reasonable positional accuracy.

  5. Aerial remote sensing surveys progress report: Helicopter geophysical survey of the Oak Ridge Reservation

    SciTech Connect

    Doll, W.E.; Nyquist, J.E.; King, A.D.; Bell, D.T.; Holladay, J.S.; Labson, V.F.; Pellerin, L.

    1993-03-01

    The 35,252 acre Department of Energy Oak Ridge Reservation (ORR) in the western portion of the Appalachian Valley and Ridge Province in Tennessee, has been a nuclear production and development facility for50 years. Contaminants in the many waste sites on the ORR include a wide variety of radioactive isotopes as well as many organic and inorganic compounds. The locations, geometry, and contents of many of these waste sites are reasonably well known, while others are poorly known or unknown. To better characterize the reasonably well known sites and search for additional potentially environmentally hazardous sites, a two-phase aerial survey of the ORR was developed. Phase I began in March 1992 and consisted of aerial radiation, multispectral scanner, and photographic (natural color and color infrared) surveys. Phase II began in November 1992 and is described in this report. Phase II consisted of helicopter electromagnetic (HEM), magnetic, and gamma radiation surveys. Targets of the survey included both man-made (drums, trench boundaries, burn pits, well heads) and geologic (fractures, faults, karst features, geologic contacts) features. The Phase II survey has three components: testing, reconnaissance, and high-resolution data acquisition. To date, the testing and reconnaissance data acquisition have been completed, and some of the data have been processed. They indicate that: (1) magnetic and HEM data are complementary and do not always highlight the same anomaly; (2) under favorable circumstances, helicopter magnetometer systems are capable of detecting groups of four or more 55-gal drums at detector altitudes of 15 m or less; (3) HEM data provide data that compare favorably with surface data collected over burial trenches, (4) well casings may be related to magnetic monopole anomalies, as would be expected; and (5) changes in HEM and magnetic anomaly character are related to lithologic changes and may be used to track contacts between known outcrops.

  6. Helicopter electromagnetic and magnetic geophysical survey data, Hunton anticline, south-central Oklahoma

    USGS Publications Warehouse

    Smith, Bruce D.; Smith, David V.; Deszcz-Pan, Maryla; Blome, Charles D.; Hill, Patricia

    2011-01-01

    This report is a digital data release for multiple geophysical surveys conducted in the Hunton anticline area of south-central Oklahoma. The helicopter electromagnetic and magnetic surveys were flown on March 16–17, 2007, in four areas of the Hunton anticline in south-central Oklahoma. The objective of this project is to improve the understanding of the geohydrologic framework of the Arbuckle-Simpson aquifer. The electromagnetic sensor for the helicopter electromagnetic survey consisted of six different transmitter-receiver orientations that measured the earth's electrical response at six distinct frequencies from approximately 500 Hertz to approximately 115,000 Hertz. The electromagnetic measurements were converted to electrical resistivity values, which were gridded and plotted on georeferenced maps. The map from each frequency represents a different depth of investigation for each area. The range of subsurface investigation is comparable to the depth of shallow groundwater. The four areas selected for the helicopter electromagnetic study, blocks A–D, have different geologic and hydrologic settings. Geophysical and hydrologic information from U.S. Geological Survey studies are being used by modelers and resource managers to develop groundwater resource plans for the Arbuckle-Simpson aquifer.

  7. Preliminary Geophysical Survey for Assessing the Geotechnical Conditions and Geohazards at Huaca de La Luna, Peru

    NASA Astrophysics Data System (ADS)

    Zavala, G. J.; Lopez, S.; Ebinger, C. J.; Pando, M. A.; Lambert, C.; Morales, R.; Uceda, S.; Perucchio, R.; Castaneda, B.; Aguilar, R.

    2014-12-01

    This paper presents results of near surface geophysical tests to help assess the geotechnical conditions of the archaeological complex of Huaca de la Luna located near the coastal city of Trujillo, Peru. This area of Peru has experienced damaging earthquakes and tsunamis in historic time. The huaca complex is a massive adobe temple progressively built by the Moche civilization from 100 AD to 650 AD. The geophysical tests carried out included Ground Penetrating Radar (GPR), magnetic gradiometer, and Multichannel Analysis of Surface Waves (MASW) to help assess geotechnical conditions such as buried cavities and hallways, thickness and elastic properties of sand sediments, and the depth to the underlying granitic bedrock. The tests were performed to help with the investigation of structural damage observed along a massive adobe wall (north façade) which has shown signs of distress including fissures, settlements, and other damage. The geophysical results together with detailed Lidar surveying are being used as part of this investigation and highlight the usefulness of these non-destructive techniques for archaeological and historical sites.

  8. Digitized data from ground geophysical surveys in Afghanistan: A website for distribution of data

    USGS Publications Warehouse

    Polster, Sarah W.; Drenth, Benjamin J.

    2011-01-01

    This document describes the process of digitization of a 1974 report on geophysical work undertaken by Soviet geophysicists in southern and eastern Afghanistan. These data, uncovered in Afghanistan, represent magnetic and electrical ground surveys for which locations are not well defined. Due to lack of location information, these surveys were georeferenced using the cities, rivers, and surrounding geology found on the maps used to plot survey locations. A geologic map found in the Soviet report contains profile lines that correspond to the geophysical maps, allowing these data to be georeferenced. The profiles correspond to sets of resistivity, chargeabiliy, and magnetic data. Some datasets were presented as graphs and needed to be gridded into a useable image. Only the vertical component of the magnetic field was collected, so conversion to total field anomaly was necessary. The magnetic data were collected in either gammas or milliorstead, both of which required conversion to standard SI units. To be useful to modern studies, the datasets and images contained in this report have been digitized, georeferenced, and in some cases converted into computer-ready formats.

  9. Survey of subsurface geophysical exploration technologies adaptable to an airborne platform

    SciTech Connect

    Taylor, K.A.

    1992-12-01

    This report has been prepared by the US Department of Energy (DOE) as part of a Research Development Demonstration Testing and Evaluation (RDDT E) project by EG G Energy Measurement's (EG G/EM) Remote Sensing Laboratory. It examines geophysical detection techniques which may be used in Environmental Restoration/Waste Management (ER/WM) surveys to locate buried waste, waste containers, potential waste migratory paths, and aquifer depths. Because of the Remote Sensing Laboratory's unique survey capabilities, only those technologies which have been adapted or are capable of being adapted to an airborne platform were studied. This survey describes several of the available subsurface survey technologies and discusses the basic capabilities of each: the target detectability, required geologic conditions, and associated survey methods. Because the airborne capabilities of these survey techniques have not been fully developed, the chapters deal mostly with the ground-based capabilities of each of the technologies, with reference made to the airborne capabilities where applicable. The information about each survey technique came from various contractors whose companies employ these specific technologies. EG G/EM cannot guarantee or verify the accuracy of the contractor information; however, the data given is an indication of the technologies that are available.

  10. Survey of subsurface geophysical exploration technologies adaptable to an airborne platform

    SciTech Connect

    Taylor, K.A.

    1992-12-01

    This report has been prepared by the US Department of Energy (DOE) as part of a Research Development Demonstration Testing and Evaluation (RDDT&E) project by EG&G Energy Measurement`s (EG&G/EM) Remote Sensing Laboratory. It examines geophysical detection techniques which may be used in Environmental Restoration/Waste Management (ER/WM) surveys to locate buried waste, waste containers, potential waste migratory paths, and aquifer depths. Because of the Remote Sensing Laboratory`s unique survey capabilities, only those technologies which have been adapted or are capable of being adapted to an airborne platform were studied. This survey describes several of the available subsurface survey technologies and discusses the basic capabilities of each: the target detectability, required geologic conditions, and associated survey methods. Because the airborne capabilities of these survey techniques have not been fully developed, the chapters deal mostly with the ground-based capabilities of each of the technologies, with reference made to the airborne capabilities where applicable. The information about each survey technique came from various contractors whose companies employ these specific technologies. EG&G/EM cannot guarantee or verify the accuracy of the contractor information; however, the data given is an indication of the technologies that are available.

  11. Geophysical survey as a basis for regeneration of waste dump Halde 10, Zwickau, Saxony

    NASA Astrophysics Data System (ADS)

    Kobr, Miroslav; Linhart, Ivan

    1994-02-01

    About 90 years ago a natural depression in the vicinity of the town of Zwickau was filled with waste left after floatation of coal exploited in the area. Later on the locality became a dumping site for municipal and industrial waste from the town of Zwickau. Waste was disposed for years without any records, and at the present time the town faces an uneasy task of securing a harmless and controlled operation of the waste dump in accordance with environmental laws now in effect in Germany. A project has been launched sponsored by the ENMOTEC GmbH, company. Tübingen, subsidiaries Freiberg and Zwickau. At the initial stages of the project an important role was played by geophysical methods applied in mapping the tectonic structure of the dumping area including other desirable geological information, mapping the extent, distribution and thickness of floatation coal layers within the mound, and mapping the disposed refuse itself. The following geoelectric methods were applied: resistivity profiling, VLF and VES. They proved to be effective tools of investigation in the specific conditions of an operating dump. Results of these measurements are presented in graphic form in schematic situation of tectonic faults and lithological boundary-lines and in a geological profile of the dump. On the basis of geophysical results monitoring boreholes were placed in the vicinity of the dump. Layers of floatation coal and of municipal and industrial waste were delineated. Another aim of the geophysical survey was to find out whether there were any active processes going on in the disposed coal refuse. A temperature survey was carried out over the dumping area in a network of points at two depth levels, 0.5 and 1 m under the surface. Localitions of anomalous temperatures with a relative increase of over 20°C and maximum values of over 40°C at 1 m depth were mapped. At the final stage of the geophysical survey logging measurements were conducted in 10 cased monitoring boreholes in the

  12. 78 FR 22239 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey on the Mid...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-15

    ... Specified Activities; Marine Geophysical Survey on the Mid-Atlantic Ridge in the Atlantic Ocean, April 2013... on the Mid-Atlantic Ridge in the north Atlantic Ocean in international waters, from April 2013... authorized takes for the seismic survey on the Mid-Atlantic Ridge in the Atlantic Ocean. The results of...

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

    SciTech Connect

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

    1985-01-01

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

  14. Exploration Geophysics

    ERIC Educational Resources Information Center

    Espey, H. R.

    1977-01-01

    Describes geophysical techniques such as seismic, gravity, and magnetic surveys of offshare acreage, and land-data gathering from a three-dimensional representation made from closely spaced seismic lines. (MLH)

  15. Geophysical and Geologic Training of the Afghan Geological Survey, May, 2008

    NASA Astrophysics Data System (ADS)

    Mooney, W. D.; Bohannon, R.; Abraham, J.; Medlin, J.

    2008-12-01

    Afghanistan lies within the Alpine-Himalayan orogeny, and consists of four primary tectonic units: (1) the North Afghan Platform, part of the greater Kazakhstan craton that includes Turkmenistan and Uzbekistan; (2) the mountainous Hindu Kush-Pamirs in the northeast; (3) the transpressional plate boundary at the Chaman fault near the border with Pakistan; and (4) the southern accreted terranes located south of the east-west oriented Herat fault. The diverse geology of Afghanistan affords the country abundant natural resources, as well as many natural hazards. In order to assist in the identification of these resources and to map hazardous faults, a multi-agency consortium including the Afghan Ministry of Mines and Industry, the USGS and the US Navel Research Lab conducted a detailed airborne geophysical survey of the western half of Afghanistan during 2007. Over 110,000 km of data were collected, including aeromagnetic, gravity, hyperspectral imagery, synthetic aperture radar and photogrammetric data. These data provide remarkable images of the surficial and sub-surface structure of the country. Armed with these new, high quality data, USGS trainers conducted an in-depth training course at the offices of the Afghan Geological Survey (AGS) during May, 2008. Eighty staff members of the AGS attended the four-day course which covered the following topics: (1) the geology and tectonics of Afghanistan; (2) a synthesis of modern plate tectonic processes; (3) use of geophysical and geological data to identify natural resources and hazardous faults. Particular emphasis was placed on oil and gas, mineral, coal and water resources. Earthquake and landslide hazards in Afghanistan were also discussed in detail. The building of scientific and technical capabilities at the AGS is a high priority because the development of their natural resources will have a positive impact on economic growth in Afghanistan. Future courses will benefit from hands-on training in methods of

  16. Helicopter Electromagnetic and Magnetic Geophysical Survey Data for Portions of the North Platte River and Lodgepole Creek, Nebraska, June 2008

    USGS Publications Warehouse

    Smith, Bruce D.; Abraham, Jared D.; Cannia, James C.; Hill, Patricia

    2009-01-01

    apparent resistivity and total magnetic field. The depth range of the subsurface investigation for the electromagnetic survey (estimated as deep as 60 m) is comparable to the depth of shallow aquifers. The geophysical data and hydrologic information from U.S. Geological Survey and cooperator studies are being used by resource managers to develop groundwater resource plans for the area. In addition, data will be used to refine hydrologic models in western Nebraska.

  17. TESTING GROUND BASED GEOPHYSICAL TECHNIQUES TO REFINE ELECTROMAGNETIC SURVEYS NORTH OF THE 300 AREA HANFORD WASHINGTON

    SciTech Connect

    PETERSEN SW

    2010-12-02

    Airborne electromagnetic (AEM) surveys were flown during fiscal year (FY) 2008 within the 600 Area in an attempt to characterize the underlying subsurface and to aid in the closure and remediation design study goals for the 200-PO-1 Groundwater Operable Unit (OU). The rationale for using the AEM surveys was that airborne surveys can cover large areas rapidly at relatively low costs with minimal cultural impact, and observed geo-electrical anomalies could be correlated with important subsurface geologic and hydrogeologic features. Initial interpretation of the AEM surveys indicated a tenuous correlation with the underlying geology, from which several anomalous zones likely associated with channels/erosional features incised into the Ringold units were identified near the River Corridor. Preliminary modeling resulted in a slightly improved correlation but revealed that more information was required to constrain the modeling (SGW-39674, Airborne Electromagnetic Survey Report, 200-PO-1 Groundwater Operable Unit, 600 Area, Hanford Site). Both time-and frequency domain AEM surveys were collected with the densest coverage occurring adjacent to the Columbia River Corridor. Time domain surveys targeted deeper subsurface features (e.g., top-of-basalt) and were acquired using the HeliGEOTEM{reg_sign} system along north-south flight lines with a nominal 400 m (1,312 ft) spacing. The frequency domain RESOLVE system acquired electromagnetic (EM) data along tighter spaced (100 m [328 ft] and 200 m [656 ft]) north-south profiles in the eastern fifth of the 200-PO-1 Groundwater OU (immediately adjacent to the River Corridor). The overall goal of this study is to provide further quantification of the AEM survey results, using ground based geophysical methods, and to link results to the underlying geology and/or hydrogeology. Specific goals of this project are as follows: (1) Test ground based geophysical techniques for the efficacy in delineating underlying geology; (2) Use ground

  18. Discovery of a new hydrothermal vent based on an underwater, high-resolution geophysical survey

    NASA Astrophysics Data System (ADS)

    Nakamura, Kentaro; Toki, Tomohiro; Mochizuki, Nobutatsu; Asada, Miho; Ishibashi, Jun-ichiro; Nogi, Yoshifumi; Yoshikawa, Shuro; Miyazaki, Jun-ichi; Okino, Kyoko

    2013-04-01

    A new hydrothermal vent site in the Southern Mariana Trough has been discovered using acoustic and magnetic surveys conducted by the Japan Agency for Marine-Earth Science and Technology's (JAMSTEC) autonomous underwater vehicle (AUV), Urashima. The high-resolution magnetic survey, part of a near-bottom geophysical mapping around a previously known hydrothermal vent site, the Pika site, during the YK09-08 cruise in June-July 2009, found that a clear magnetization low extends ˜500 m north from the Pika site. Acoustic signals, suggesting hydrothermal plumes, and 10 m-scale chimney-like topographic highs were detected within this low magnetization zone by a 120 kHz side-scan sonar and a 400 kHz multibeam echo sounder. In order to confirm the seafloor sources of the geophysical signals, seafloor observations were carried out using the deep-sea manned submersible Shinkai 6500 during the YK 10-10 cruise in August 2010. This discovered a new hydrothermal vent site (12°55.30'N, 143°38.89'E; at a depth of 2922 m), which we have named the Urashima site. This hydrothermal vent site covers an area of approximately 300 m×300 m and consists of black and clear smoker chimneys, brownish-colored shimmering chimneys, and inactive chimneys. All of the fluids sampled from the Urashima and Pika sites have chlorinity greater than local ambient seawater, suggesting subseafloor phase separation or leaching from rocks in the hydrothermal reaction zone. End-member compositions of the Urashima and Pika fluids suggest that fluids from two different sources feed the two sites, even though they are located on the same knoll and separated by only ˜500 m. We demonstrate that investigations on hydrothermal vent sites located in close proximity to one another can provide important insights into subseafloor hydrothermal fluid flow, and also that, while such hydrothermal sites are difficult to detect by conventional plume survey methods, high-resolution underwater geophysical surveys provide an

  19. Combining Geological and Geophysical Surveys with Cave Explorations for the Assessment of the Sinkhole Susceptibility in Coastal Areas

    NASA Astrophysics Data System (ADS)

    Margiotta, Stefano; Negri, Sergio; Pagliara, Antonio; Parise, Mario; Quarta, Tatiana A. M.

    2013-04-01

    Evaluating the susceptibility related to occurrence of sinkholes is of particular relevance in coastal settings, due to the likely high frequency of sinkholes, that are especially favored by the interaction between fresh and brackish water, with the consequent strong aggressivity on the soluble rock masses. Long stretches of the Ionian coastline (southern Apulia, SE Italy) are affected by sinkholes, that in more than one occasion have caused significant damage and problems to the human infrastructures, and in particular to the main communication routes in the area. In this study, we combine the outcomes of different methodologies to reach a good understanding of the sinkhole susceptibility in the area of Torre Castiglione, in the proximity of Porto Cesareo (Lecce province): starting from geological analysis, and the building up of a detailed database on the sinkholes in the study area, the obtained data were used to plan the following research, consisting of geophysical surveys, that were carried out with different techniques. At the same time, cave explorations (including scuba-diving) were performed in one of the most important sinkhole at Torre Castiglione: this phase of the activity allowed to get remarkable insights into the features of the submerged karst systems in the area. Flooded passages, 4 to 9 mt-wide and 5,5 mt-high, were explored for several tens of meters. A chaotic jumble of breakdown deposits constitute the cave pavement, and the vault and walls of the passages are heavily fractured, pointing out to the possibility of further detachments, which likely will result in opening additional sinkholes at the surface. The underground systems appear to be quite complex and extensive, but the difficulty in the explorations (mostly due to narrowing of the passages and to the rock mass instability) suggested to stop the scuba-diving activity for safety reasons. Sinkholes detection and imaging is a challenging task for geophysical methods, not only because of

  20. Geophysical survey of Neovolcanic complexes in the first protection zone of the Sliač Spa and the Baková jama

    NASA Astrophysics Data System (ADS)

    Pašiaková, Mariana; Gajdoš, Vojtech; Bučová, Jana; Dérerová, Jana; Straka, Adam; Hlavˇnová, Petra; Brixová, Bibiana

    2014-03-01

    The main purpose of the survey in the 1st protection zone area of the Sliač Spa and the Baková jama was to clarify the geological-tectonical structure. The vertical electric sounding (VES) technique was selected as the main geophysical survey method. Additionally, the soil radon emanometry was carried out to verify tectonic lines' presence. The outcrop of Pre-Tertiary basement was discovered in the form of small isolated island. No tectonic line was identified based on the evaluation of profile radon concentration. The results of geoelectrical measurements are presented in 8 geological-geophysical crosssections. The results and the tectonic lines' courses interpreted by the VES method are drawn in the map of new indications. The isoline maps and 3D model of Pre-Tertiary basement were constructed.

  1. Non-Destructive Survey of Archaeological Sites Using Airborne Laser Scanning and Geophysical Applications

    NASA Astrophysics Data System (ADS)

    Poloprutský, Z.; Cejpová, M.; Němcová, J.

    2016-06-01

    This paper deals with the non-destructive documentation of the "Radkov" (Svitavy district, Czech Republic) archaeological site. ALS, GPR and land survey mapping will be used for the analysis. The fortified hilltop settlement "Radkov" is an immovable historical monument with preserved relics of anthropogenic origin in relief. Terrain reconnaissance can identify several accentuated objects on site. ALS enables identification of poorly recognizable archaeological objects and their contexture in the field. Geophysical survey enables defunct objects identification. These objects are hidden below the current ground surface and their layout is crucial. Land survey mapping provides technical support for ALS and GPR survey. It enables data georeferencing in geodetic reference systems. GIS can then be used for data analysis. M. Cejpová and J. Němcová have studied this site over a long period of time. In 2012 Radkov was surveyed using ALS in the project "The Research of Ancient Road in Southwest Moravia and East Bohemia". Since 2015 the authors have been examining this site. This paper summarises the existing results of the work of these authors. The digital elevation model in the form of a grid (GDEM) with a resolution 1 m of 2012 was the basis for this work. In 2015 the survey net, terrain reconnaissance and GPR survey of two archaeological objects were done at the site. GDEM was compared with these datasets. All datasets were processed individually and its results were compared in ArcGIS. This work was supported by the Grant Agency of the CTU in Prague, grant No. SGS16/063/OHK1/1T/11.

  2. Integrated Geophysical Survey on Deák Ferenc Sluice in Hungary

    NASA Astrophysics Data System (ADS)

    Kanli, A. I.

    2015-12-01

    ALI ISMET KANLI1*, G. TALLER2, Z. PRONAY2, P. TILDY2, P. NAGY3, E. TOROS2 *1Istanbul University, Turkey, kanli@istanbul.edu.tr, 2Geological and Geophysical Institute of Hungary,3MinGeo, Hungary The Ferenc Channel is one of the main irrigation and ship channel in south of Hungary, existing from 1801. The water level is controlled by the Deák Ferenc Sluice in the channel which was constructed in 1875. At that time, the sluice was unique in Europe with its two channels and brick-walls. The west channel was used for controlling the amount of water and the east channel was used for shipping. In the study, before starting to the restoration and reinforcement plannings at the sluice, non-destructive geophysical investigations were executed. In the first stage, ultra-high frequency seismic (80 kHz) and acoustic (5 kHz) investigations of the floor slab were carried out from a boat on the water level. Due to the water level was approximately 2 m, we could use the advantage of the water ensuring very good coupling with seismic sensors for high frequency seismic and acoustic measurements. In the second stage, resistivity measurements were carried out in the eastern part of the sluice which was used as the shipping channel. Three profiles were measured to map the resistivity distribution of the slab. In the third stage, for better understanding the stability conditions of the walls and easy to compare with the data of GPR measurements, the wall of the sluice were investigated by a simple seismic direct wave method using seismic P-waves for mapping seismic velocities. The last stage of the survey was the GPR measurements that were carried out both on the walls and on the slab of the sluice. During the investigation, the channels were empty and without water. The integrated survey and the interpretation of the results showed us that there were some faults, cracks and voids in the slab existed in the whole grossness of the slab and the brick walls were builded from inhomogenous

  3. Three decades of BGR airborne geophysical surveys over the polar regions - a review

    NASA Astrophysics Data System (ADS)

    Damaske, Detlef

    2013-04-01

    The Federal Institute for Geosciences and Natural Resources (BGR) has been conducting geological polar research since 1979. A few years later BGR engaged in airborne geophysical projects. Investigation of the lithosphere of the continent and the continental margins was one of the key issues for BGR. Right from the beginning geophysical research was closely associated with the geological activities. The GANOVEX (German Antarctic North Victoria Land Expedition) program combined geological research with geophysical (mainly airborne) investigations. This proved to be a fruitful approach to many of the open questions regarding the tectonic development of the Ross Sea region. Aeromagnetic surveys evolved into a powerful tool for identifying geological structures and following them underneath the ice covered areas - not accessible to direct geological investigations. To achieve this aim it was essential to lay out these surveys with a relatively closely spaced line separation on the expense of covering large areas at the same time. Nevertheless, over many years of continues research areas of more than a just regional extent could be covered. This was, however, only possible through international collaboration. During the first years, working in the Ross Sea area, the cooperation with the US and Italian programs played a significant role, especially the GITARA (German-Italian Aeromagnetic Research in Antarctica) program has to be mentioned. GEOMAUD (Geoscientific Expedition to Dronning Maud Land) and the German-Australian joint venture PCMEGA (Prince Charles Mountains Expedition of Germany & Australia) expanded research activities to the East Antarctic shield area. In the International Polar Year (IPY), BGR played a leading role in the international project AGAP (Antarctica's GAmburtsev Province) as part of the main topic "Venture into Unknown Regions". AGAP was jointly conducted by the USA, Great Britain, Australia, China and Germany. While in the Ross Sea area even

  4. Geophysical surveys aimed to save human lives by facilitating safety assessment

    NASA Astrophysics Data System (ADS)

    Kaminskiy, Vladislav F.

    Two research projects by the Water and Energy Team of the National Energy Technology Laboratory were carried out in collaboration between the US Department of Energy and the University of Pittsburgh. Both projects are related to investigating current and potential impacts of abandoned coal mines on the adjacent populated regions. The first project was carried out in West Virginia over 14 active and abandoned coal slurry impoundments (Appendix A) in order to remotely investigate their current condition and potential hazards related to the mine-waste pools. Three main scenarios of impoundment failure are overtopping of the impoundment, internal erosion (piping) and entry of unconsolidated material into adjacent mine voids due to subsidence. To characterize these potential hazards, helicopter-mounted electromagnetic (HEM) surveys were completed to identify fluid saturated zones within coal waste and to delineate the paths of filtrate fluid flow. Attempts were also made to identify flooded mine workings underlying the impoundment areas. A total of 431 flight lines were processed, each from 2 to over 4 km in length, in total more than 1300 line-kilometers of HEM survey. Follow-up, ground-based resistivity surveys verified the results of the HEM investigations. The HEM and ground-based geophysical surveys proved to be effective in delineating the phreatic surface, determining seep locations, imaging areas of unconsolidated slurry, locating areas where process water has invaded adjacent aquifers, potentially depicting the possible location of flooded underground mine workings and locating infiltration zones. The second project took place in southwestern Pennsylvania. In order to image beneath the surface and identify zones of possible gas accumulation and migration routes, reflection seismic surveys were completed in this area. Seismic imaging was successful in identifying regions of subsurface gas accumulation. Because of the urban nature of the survey, it was very

  5. Integrated geophysical surveys for mapping lati-andesite intrusive bodies, Chino Valley, Arizona

    USGS Publications Warehouse

    El-Kaliouby, Hesham; Sternberg, Ben K.; Hoffmann, John P.; Langenheim, V.E.

    2012-01-01

    Three different geophysical methods (magnetic, transient electromagnetic (TEM) and gravity) were used near Chino Valley, Arizona, USA in order to map a suspected lati-andesite intrusive body (plug) previously located by interpretation of aeromagnetic data. The magnetic and TEM surveys provided the best indication of the location and depth of the plug. The north-south spatial extent of this plug was estimated to be approximately 600 meters. The depth to the top of the plug was found from the TEM survey to be approximately 350 meters near the center of the survey. The location of the plug defined by the ground magnetic data is consistent with that from the TEM data. Gravity data mostly image the basin-basement interface with a small contribution from the plug of about 0.5 mGal. Results from this investigation can be used to help define the irregular subsurface topography caused by several intrusive lati-andesite plugs that could influence groundwater flow in the area.

  6. Regional Geophysical Surveys and Crustal Structure of the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Rodríguez-Chavez, F.; Fucugauchi, J. U.

    2007-05-01

    Results of processing and modeling of anomaly data from regional geophysical surveys in the southern sector of the Gulf of Mexico are presented. The Gulf of Mexico has been intensively studied for several years, mainly because of the economic potential of the oil and gas resources. The basin may have formed by sea-floor spreading, rifting and lateral translation/rotation of continental slivers ssociated with major break-up and drifting apart of North and South America continental plates in the mid Mesozoic. Major structural features and crustal structure, including the continent-ocean transition and Gulf coastal passive margin are relatively poorly understood. Aerogeophysical gravity and magnetic surveys have been conducted and data are processed and modeled to investigate on the Gulf crustal structure. Spectral statistical estimates of regional basement depths derived from aeromagnetics give mean depths of 8000 m. Estimates derived from gravity anomalies are in the order of 10000 m. Depths derived from 2D and 3D seismic reflection surveys conducted for oil exploration purposes in selected areas indicate average depths to basement from 6000 m to values grater than those derived from potential field data.

  7. Geophysical methods

    SciTech Connect

    Robert, E.S.

    1989-01-01

    Geophysical measurements involve no magic or mystery but straightforward applications of physical principles. This book is both a geophysical survey and a reference guide. It explains the physical principles involved in geophysical methods. Over one-third of the text is devoted to seismic methods. Comprehensive topics in the volume include: the measurement of different physical properties and their geological significance; how different kinds of measurements are combined to draw geological conclusions; surface, borehole, airborne, and satellite measurements; computer processing and interactive methods; geodetic, gravity, magnetic, radioactive, heat flow, and electrical methods; interpretation of natural processes such as earthquakes and heat flow; and a summation of present knowledge of the earth.

  8. Petrophysical analysis of geophysical logs of the National Drilling Company-U.S. Geological Survey ground-water research project for Abu Dhabi Emirate, United Arab Emirates

    USGS Publications Warehouse

    Jorgensen, Donald G.; Petricola, Mario

    1994-01-01

    A program of borehole-geophysical logging was implemented to supply geologic and geohydrologic information for a regional ground-water investigation of Abu Dhabi Emirate. Analysis of geophysical logs was essential to provide information on geohydrologic properties because drill cuttings were not always adequate to define lithologic boundaries. The standard suite of logs obtained at most project test holes consisted of caliper, spontaneous potential, gamma ray, dual induction, microresistivity, compensated neutron, compensated density, and compensated sonic. Ophiolitic detritus from the nearby Oman Mountains has unusual petrophysical properties that complicated the interpretation of geophysical logs. The density of coarse ophiolitic detritus is typically greater than 3.0 grams per cubic centimeter, porosity values are large, often exceeding 45 percent, and the clay fraction included unusual clays, such as lizardite. Neither the spontaneous-potential log nor the natural gamma-ray log were useable clay indicators. Because intrinsic permeability is a function of clay content, additional research in determining clay content was critical. A research program of geophysical logging was conducted to determine the petrophysical properties of the shallow subsurface formations. The logging included spectral-gamma and thermal-decay-time logs. These logs, along with the standard geophysical logs, were correlated to mineralogy and whole-rock chemistry as determined from sidewall cores. Thus, interpretation of lithology and fluids was accomplished. Permeability and specific yield were calculated from geophysical-log data and correlated to results from an aquifer test. On the basis of results from the research logging, a method of lithologic and water-resistivity interpretation was developed for the test holes at which the standard suite of logs were obtained. In addition, a computer program was developed to assist in the analysis of log data. Geohydrologic properties were

  9. 77 FR 19242 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ...NMFS has received an application from Lamont-Doherty Earth Observatory (L-DEO), a part of Columbia University, for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting a low-energy marine geophysical survey in the central Pacific Ocean, May through June, 2012. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting......

  10. 78 FR 33369 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-04

    ...In accordance with the Marine Mammal Protection Act (MMPA) regulations, notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to the U.S. Geological Survey (USGS) to take marine mammals, by Level B harassment, incidental to conducting a low-energy marine geophysical (i.e., seismic) survey in the deep water of the Gulf of Mexico, April to May...

  11. An Analysis of Wind Power Development in the Town of Hull, MA_Appendix 4_Geophysical Survey Report

    SciTech Connect

    Adams, Christopher

    2013-06-30

    CR Environmental, Inc. (CR) was contracted by GZA GeoEnvironmental, Inc. (GZA) to perform hydrographic and geophysical surveys of an approximately 3.35 square mile area off the eastern shore of Hull, Massachusetts. Survey components included: • Single-beam bathymetry; • 100-kHz and 500-kHz side scan sonar; • Magnetometry; and • Low to mid-frequency sub-bottom profiling.

  12. 78 FR 11821 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ...NMFS has received an application from the U.S. Geological Survey (USGS), for an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting a low-energy marine geophysical (seismic) survey in the Gulf of Mexico, April to May, 2013. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an IHA to......

  13. Airborne electromagnetic and magnetic geophysical survey data of the Yukon Flats and Fort Wainwright areas, central Alaska, June 2010

    USGS Publications Warehouse

    Ball, Lyndsay B.; Smith, Bruce D.; Minsley, Burke J.; Abraham, Jared D.; Voss, Clifford I.; Astley, Beth N.; Deszcz-Pan, Maria; Cannia, James C.

    2011-01-01

    In June 2010, the U.S. Geological Survey conducted airborne electromagnetic and magnetic surveys of the Yukon Flats and Fort Wainwright study areas in central Alaska. These data were collected to estimate the three-dimensional distribution of permafrost at the time of the survey. These data were also collected to evaluate the effectiveness of these geophysical methods at mapping permafrost geometry and to better define the physical properties of the subsurface in discontinuous permafrost areas. This report releases digital data associated with these surveys. Inverted resistivity depth sections are also provided in this data release, and data processing and inversion methods are discussed.

  14. Geophysical survey at cluster 6, Westwood Area, US Army Aberdeen Proving Ground. Final report

    SciTech Connect

    Simms, J.E.; Harrelson, D.W.; Sharp, M.K.

    1995-05-01

    A geophysical investigation was conducted at Cluster 6 Site 5, located in Westwood Area of the U.S. Army Aberdeen Proving Ground. This site is the former Westwood Area Radioactive Material Disposal Facility (WRMDF) which was used for processing and packaging radioactive waste material prior to disposal. Original structures at the site included Building 3013 and adjacent concrete slabs where the waste handling work was performed, a small equipment shed, and a wastewater holding and drain system which included tanks in a concrete pit. Discharge of wastewater from the tanks was to Reardon Inlet, located a short distance south of the tank pit. Possible release of radioactive waste to the environment would have been due to either spillage, leakage, or discharge from the wastewater system. Two terra cotta pipelines, one on the western end and one of the eastern end, extended from Building 3013 to Reardon Inlet. The east pipeline handled low-level radioactive wastewater. The west pipeline was the original wastewater line and it is presumed that radioactive wastewater was not discharged through this line. After radioactive waste handling activities were discontinued at WRMDF, the west pipeline system was upgraded to include a septic tank, sand filter bed, and a chlorine contact chamber. The structures associated with the WRMDF were removed during the early 1970`s, including the concrete tank pit. Both pipelines are visible near the edge of Reardon inlet, suggesting that the pipes and related structures have not been removed. Geophysical surveys, including magnetics, electromagnetics (EM), and ground penetrating radar, were performed to identify the location of the two terra cotta pipes, septic tank, and sand filter bed.

  15. Bathymetric and geophysical surveys of Englebright Lake, Yuba-Nevada Counties, California

    USGS Publications Warehouse

    Childs, Jonathan R.; Snyder, Noah P.; Hampton, Margaret A.

    2003-01-01

    Harry L. Englebright Lake is a 9-mile-long (14-kilometer) reservoir located in the Sierra Nevada foothills of northern California on the Yuba River gorge known as The Narrows. The reservoir is impounded by Englebright Dam (Photo 1), a concrete arch structure spanning 348 meters (1,142 feet) across and 79 meters (260 feet) high. The dam was constructed in 1941 for the primary purpose of trapping sediment derived from anticipated hydraulic mining operations in the Yuba River watershed. Hydraulic mining in the Sierra Nevada was halted in 1884 but resumed on a limited basis until the 1930's under the regulation of the California Debris Commission. Although no hydraulic mining in the upper Yuba River watershed resumed after the construction of the dam, the historical mine sites continued to contribute sediment to the river. Today, Englebright Lake is used primarily for recreation and hydropower. In 2001 and 2002, the U.S. Geological Survey (USGS) conducted bathymetric, geophysical, and geological studies of the reservoir under the auspices of the Upper Yuba River Studies Program (UYRSP), a multi-disciplinary investigation into the feasibility of introducing anadromous fish species to the Yuba River system upstream of Englebright Dam. A primary purpose of these studies was to assess the quantity and nature of the sediment that has accumulated behind the dam over the past 60 years. This report presents the results of those surveys, including a new bathymetric map of the reservoir and estimates of the total accumulated sediment volume.

  16. Geophysical Surveying of Shallow Magnetic Anomalies Using the iPhone Magnetometer

    NASA Astrophysics Data System (ADS)

    Opdyke, P.; Dudley, C.; Louie, J. N.

    2012-12-01

    This investigation examined whether the 3-axis Hall-effect magnetometer in the Apple iPhone 3GS can function as an effective shallow magnetic survey instrument. The xSensor Pro app from Crossbow Systems allows recoding of all three sensor components along with the GPS location, at a frequency of 1.0, 4.0, 16.0, and 32.0 Hz. If the iPhone proves successful in collecting useful magnetic data, then geophysicists and especially educators would have a new tool for high-density geophysical mapping. No-contract iPhones that can connect with WiFi can be obtained for about $400, allowing deployment of large numbers of instruments. iPhones with the xSensor Pro app surveyed in parallel with an Overhauser GEM system magnetometer (1 nT sensitivity) to test this idea. Anderson Bay, located on the Pyramid Lake Paiute Reservation, provided a rural survey location free from cultural interference. xSensor Pro, logged each component's intensity and the GPS location at a frequency of four measurements per second. Two Overhauser units functioned as a base unit and a roving unit. The roving unit collected total field at set points located with a handheld GPS. Comparing the total field computed from the iPhone components against that collected by the Overhauser establishes the level of anomalies that the iPhone can detect. iPhone total-field measurements commonly vary by 200 nT from point to point, so a spatial-temporal average over 25 seconds produces a smoothed signal for comparison. Preliminary analysis of the iPhone results show that the data do not accurately correlate to the total field collected by the Overhauser for any anomaly of less than 200 nT.

  17. Characteristics of fractures in crystalline bedrock determined by surface and borehole geophysical surveys, eastern surplus superfund site, Meddybemps, Maine

    USGS Publications Warehouse

    Hansen, Bruce P.; Stone, Janet Radway; Lane, Jr., John W.

    1999-01-01

    Surface and borehole geophysical methods were used to determine fracture orientation in crystalline bedrock at the Eastern Surplus Superfund Site in Meddybemps, Maine. Fracture-orientation information is needed to address concerns about the fate of contaminants in ground water at the site. Azimuthal square-array resistivity surveys were conducted at 3 locations at the site, borehole-acoustic televiewer and borehole-video logs were collected in 10 wells, and single-hole directional radar surveys were conducted in 9 wells. Borehole-video logs were used to supplement the results of other geophysical techniques and are not described in this report. Analysis of azimuthal square-array resistivity data indicated that high-angle fracturing generally strikes northeast-southwest at the three locations. Borehole-acoustic televiewer logs detected one prominent low-angle and two prominent high-angle fracture sets. The low-angle fractures strike generally north-northeast and dip about 20 degrees west-northwest. One high-angle fracture set strikes north-northeast and dips east-southeast; the other high-angle set strikes east-northeast and dips south-southeast. Single-hole directional radar surveys identified two prominent fracture sets: a low-angle set striking north-northeast, dipping west-northwest; and a high-angle fracture set striking north-northeast, dipping east-southeast. Two additional high-angle fracture sets are defined weakly, one striking east-west, dipping north; and a second striking east-west, dipping south. Integrated results from all of the geophysical surveys indicate the presence of three primary fracture sets. A low-angle set strikes north-northeast and dips west-northwest. Two high-angle sets strike north-northeast and east-northeast and dip east-southeast and south-southeast. Statistical correction of the fracture data for orientation bias indicates that high-angle fractures are more numerous than observed in the data but are still less numerous than the

  18. Integrated geophysical survey in defining subsidence features on a golf course

    USGS Publications Warehouse

    Xia, J.; Miller, R.D.

    2007-01-01

    Subsidence was observed at several places on the Salina Municipal Golf Course in areas known to be built over a landfill in Salina, Kansas. High-resolution magnetic survey (???5400 m2), multi-channel electrical resistivity profiling (three 154 m lines) and microgravity profiling (23 gravity-station values) were performed on a subsidence site (Green 16) to aid in determining boundaries and density deficiency of the landfill in the vicinity of the subsidence. Horizontal boundaries of the landfill were confidently defined by both magnetic anomalies and the pseudo-vertical gradient of total field magnetic anomalies. Furthermore, the pseudo-vertical gradient of magnetic anomalies presented a unique anomaly at Green 16, which provided a criterion for predicting other spots with subsidence potential using the same gradient property. Results of multi-channel electrical resistivity profiling (ERP) suggested the bottom limit of the landfill at Green 16 was around 21 m below the ground surface based on the vertical gradient of electric resistivity and a priori information on the depth of the landfill. ERP results also outlined several possible landfill bodies based on their low resistivity values. Microgravity results suggested a -0.14 g cm-3 density deficiency at Green 16 that could equate to future surface subsidence of as much as 1.5 m due to gradual compaction. ?? 2007 Nanjing Institute of Geophysical Prospecting.

  19. Geophysical survey of the intra-caldera icefield of Mt Veniaminof, Alaska

    NASA Astrophysics Data System (ADS)

    Welch, Brian C.; Dwyer, Kieran; Helgen, Michael; Waythomas, Christopher F.; Jacobel, Robert W.

    Mt Veniaminof is a large active stratovolcano located on the Alaska Peninsula (56.2° N, 159° W). We present results of the first geophysical survey of the icefield that fills much of the 10 km × 8 km caldera that was most recently modified during the last major eruption roughly 3700 BP. The subglacial topography and ice volume are derived from an 8 MHz radio-echo sounding survey conducted in July 2005. Prominent internal reflectors are assumed to be isochronal ash/acid deposits related to local eruptions. Accumulation rates and basal melt rates are calculated using a Nye onedimensional steady-state accumulation model applied at a location that approximates an ice divide and calibrated by matching internal reflectors with published records of recent local volcanic eruptions. The model yields order of magnitude estimates of the accumulation rate of 4m a-1 water equivalent and 2m a-1 of basal melt. The subsequent geothermal flux of ˜19W m-2 is similar to active hydrothermal vents in volcanic lakes. We suggest that these values represent an upper limit for the geothermal flux within the ice-covered regions of the main caldera. We also analyze likely subglacial meltwater flow paths to examine the implications of recent eruption activity at an active intra-caldera cinder cone. Two lava-producing eruptions from the cinder cone in 1983-84 and 1993-94 melted roughly 0.17 km3 of ice. The lack of significant deformation of the internal stratigraphy to the south and east of the melt hole suggests that any subglacial drainage in those directions was entirely within subglacial deposits. We suggest that the more likely drainage route was northwest into a large outlet glacier.

  20. Airborne geophysical survey of ice caps in the Queen Elizabeth Islands, Arctic Canada

    NASA Astrophysics Data System (ADS)

    Palmer, S. J.; Dowdeswell, J. A.; Christoffersen, P.; Benham, T. J.; Young, D. A.; Blankenship, D. D.; Richter, T.; Ng, G.; Grima, C.; Habbal, F.; Sharp, M. J.; Rutishauser, A.

    2014-12-01

    Previous studies have shown that between 2003 and 2009, 60 ± 6 Gt of ice was lost each year from the Canadian Arctic (Gardner et al., 2013), making the region the largest cryospheric contributor to global sea level rise outside of the great ice sheets. Glacier ice in the Queen Elizabeth Islands (QEI) currently covers more than 100,000 km2, representing 20% of Earth's ice-covered land area outside of Greenland and Antarctica. The vast majority of this ice is stored within six ice caps located on Ellesmere, Devon and Axel Heiberg islands. Recent satellite observations of the outlet glaciers draining these ice caps have revealed significant velocity variability on inter-annual and multi-year timescales (Van Wychen et al., 2014), though the drivers of these dynamics are not yet understood. Here we present results obtained in May 2014 during an airborne geophysical survey of the ice caps of Axel Heiberg, Ellesmere and Devon islands, including Agassiz Ice Cap (17,300 km2), Prince of Wales Icefield (19,300 km2) and Devon Ice Cap (14,000 km2). We used a Basler BT-67 aircraft equipped with a suite of geophysical instruments, including a phase-coherent VHF ice-penetrating radar, to measure ice thickness and investigate ice basal conditions along outlet glacier flow lines and in the interior of the ice caps. We reveal that the glaciers draining the ice caps of the QEI exhibit diverse characteristics over short spatial scales, and that fast-flowing tidewater glaciers are located adjacent to previously fast-flowing areas that have subsequently stagnated. Our results show that many ice cap outlet glaciers on Ellesmere and Devon islands are between 700 and 1000 m thick and flow through deep bedrock troughs whose beds lie below sea-level. Some of the outlet glaciers also have floating tongues of ice which extend into the adjacent fjord waters. We intend to use our results to characterize the substrate beneath the ice, and to reveal any variations in conditions at the ice

  1. Comprehensive clues provided by popular free remote sensing imagery to interpretation of geophysical studies explained by example cases of magnetic surveys

    NASA Astrophysics Data System (ADS)

    Arafa-Hamed, Tarek

    2013-12-01

    State-of-the-art remote sensing technologies for imaging the earth and its shallow subsurface are invaluable tools for sophisticated geophysical subsurface investigations. However, such type of remote sensing products remains inaccessible for most of geophysicists. On the other hand free simple satellite imagery has been commonly available since mid-last decade. Google Earth™ is a popular free Internet application through which users can view landscapes and maps. In this work it is shown how easy and efficient it is to access the open-source of remote sensing in geophysical surveys to provide a quick overview for survey plans and comprehensive keys for interpretation based on cases of magnetic measurements. A dry well that has been drilled in an aquifer few tens of meters away from a productive water well in Dahshour has been preliminary explained by considering Google Earth images. The images of the area show clear differentiation of surface lithology into 2 zones with a sharp interface. Magnetic anomaly map of Dahshour fault raised two unclear features that might be interpreted by a curvature in Dahshour fault plane and an additional perpendicular fault trending N-S. The Google Earth imagery gives clues to basaltic intrusions to be the cause of the suspected gradients. A continuous boat-born magnetic survey carried out in Nasser Lake, southern High Dam, reveals several characteristic anomalies. Visual inspection of Google-Earth images at various altitudes (zooms) indicates a relation between the anomalies and major faulting structures.

  2. Helicopter electromagnetic and magnetic geophysical survey data, portions of the North Platte and South Platte Natural Resources Districts, western Nebraska, May 2009

    USGS Publications Warehouse

    Smith, B.D.; Abraham, J.D.; Cannia, J.C.; Minsley, B.J.; Deszcz-Pan, M.; Ball, L.B.

    2010-01-01

    This report is a release of digital data from a helicopter electromagnetic and magnetic survey that was conducted during June 2009 in areas of western Nebraska as part of a joint hydrologic study by the North Platte Natural Resource District (NRD), South Platte NRD, and U.S. Geological Survey (USGS). Flight lines for the survey totaled 937 line kilometers (582 line miles). The objective of the contracted survey, conducted by Fugro Airborne, Ltd., is to improve the understanding of the relation between surface-water and groundwater systems critical to developing groundwater models used in management programs for water resources. A unique aspect of the survey is the flight line layout. One set of flight lines was flown in a zig-zag pattern extending along the length of the previously collected airborne data. The success of this survey design depended on a well-understood regional hydrogeologic framework and model developed by the Cooperative Hydrologic Study of the Platte River Basin and the airborne geophysical data collected in 2008. Resistivity variations along lines could be related to this framework. In addition to these lines, more traditional surveys consisting of parallel flight lines, separated by about 400 meters were carried out for three blocks in the North Platte NRD, the South Platte NRD and in the area of Crescent Lakes. These surveys helped to establish the spatial variations of the resistivity of hydrostratigraphic units. An additional survey was flown over the Crescent Lake area. The objective of this survey, funded by the USGS Office of Groundwater, was to map shallow hydrogeologic features of the southwestern part of the Sand Hills that contain a mix of fresh to saline lakes.

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

    USGS Publications Warehouse

    Gray, J. E.; Page, W.R.

    2008-01-01

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

  4. Airborne Geophysical Surveys Illuminate the Geologic and Hydrothermal Framework of the Pilgrim Springs Geothermal Area, Alaska

    NASA Astrophysics Data System (ADS)

    McPhee, D. K.; Glen, J. M.; Bedrosian, P. A.

    2012-12-01

    An airborne magnetic and frequency-domain electromagnetic (EM) survey of the Pilgrim Springs geothermal area, located on the Seward Peninsula in west-central Alaska, delineates key structures controlling hydrothermal fluid flow. Hot springs, nearby thawed regions, and high lake temperatures are indicative of high heat flow in the region that is thought to be related to recent volcanism. By providing a region-wide geologic and geophysical framework, this work will provide informed decisions regarding drill-site planning and further our understanding of geothermal systems in active extensional basins. Helicopter magnetic and EM data were acquired using a Fugro RESOLVE system equipped with a high sensitivity cesium magnetometer and a multi-coil, multi-frequency EM system sensitive to the frequency range of 400-140,000 Hz. The survey was flown ~40 m above ground along flight lines spaced 0.2-0.4 km apart. Various derivative and filtering methods, including maximum horizontal gradient of the pseudogravity transformation of the magnetic data, are used to locate faults, contacts, and structural domains. A dominant northwest trending anomaly pattern characterizes the northeastern portion of the survey area between Pilgrim Springs and Hen and Chickens Mountain and may reflect basement structures. The area south of the springs, however, is dominantly characterized by east-west trending, range-front-parallel anomalies likely caused by late Cenozoic structures associated with the north-south extension that formed the basin. Regionally, the springs are characterized by a magnetic high punctuated by several east-west trending magnetic lows, the most prominent occurring directly over the springs. The lows may result from demagnetization of magnetic material along range-front parallel features that dissect the basin. We inverted in-phase and quadrature EM data along each profile using the laterally-constrained inversion of Auken et al. (2005). Data were inverted for 20-layer

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

    SciTech Connect

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

    1999-11-14

    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.

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

    SciTech Connect

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

    1998-12-01

    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.

  7. Orientation and characteristics of fractures in crystalline bedrock determined by surface and borehole geophysical surveys, Millville and Uxbridge, Massachusetts

    SciTech Connect

    Hansen, B.P.; Lane, J.W.

    1996-11-01

    Four Geophysical techniques were used to determine bedrock fracture orientation and other site characteristics that can be used to determine ground-water flow and contaminant transport at a study area underlain by fractured crystalline bedrock in Millville and Uxbridge, Massachusetts. In the study area, azimuthal seismic-refraction and azimuthal square-array direct-current resistivity surveys were conducted at three sites, borehole-radar surveys were conducted in a cluster of three wells, and ground-penetrating radar surveys were conducted along roads. Azimuthal seismic-refraction data indicated a primary fracture strike ranging from 56 to 101 degrees at the three sites. Graphical and analytical analysis of azimuthal square-array resistivity data indicated a primary fracture strike ranging from 45 to 90 degrees at the same three sites. Directional borehole-radar data from three wells indicated 46 fractures or fracture zones located as far as 147 feet from the surveyed wells. Patterns of low radar-wave velocity and high radar-wave attenuation from cross-hole radar surveys of two well pairs were interpreted as a planar fracture zone that strikes 297 degrees and dips 55 degrees south. Ground-penetrating radar surveys with 100-MHz antennas penetrated 5 to 50 feet of unconsolidated overburden and as much as 60 feet of bedrock where the bedrock surface was at or near land surface. Horizontal and subhorizontal fractures were observed on the ground-penetrating radar records at numerous locations. Comparison of results from the various Geophysical techniques indicates good agreement and indicates primary high-angle fracturing striking east-northeast. Square-array resistivity data yielded an average secondary bedrock porosity of 0.0044 and an average aperture of 0.0071 foot for high-angle fractures.

  8. 76 FR 37066 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... in or near the proposed seismic survey areas. This document presents a new table with corrections... densities of marine mammals that may occur in or near the proposed seismic survey area. Accordingly, Table...

  9. A survey of natural aggregate properties and characteristics important in remote sensing and airborne geophysics

    USGS Publications Warehouse

    Knepper, D.H.; Langer, W.H.; Miller, S.

    1995-01-01

    Natural aggregate is vital to the construction industry. Although natural aggregate is a high volume/low value commodity that is abundant, new sources are becoming increasingly difficult to find and develop because of rigid industry specifications, political considerations, development and transportation costs, and environmental concerns. There are two primary sources of natural aggregate: (1) exposed or near-surface bedrock that can be crushed, and (2) deposits of sand and gravel. Remote sensing and airborne geophysics detect surface and near-surface phenomena, and may be useful for detecting and mapping potential aggregate sources; however, before a methodology for applying these techniques can be developed, it is necessary to understand the type, distribution, physical properties, and characteristics of natural aggregate deposits. The distribution of potential aggregate sources is closely tied to local geologic history. Conventional exploration for natural aggregate deposits has been largely a ground-based operation, although aerial photographs and topographic maps have been extensively used to target possible deposits. Today, the exploration process also considers factors such as the availability of the land, space and water supply for processing, political and environmental factors, and distance from the market; exploration and planning cannot be separated. There are many physical properties and characteristics by which to judge aggregate material for specific applications; most of these properties and characteristics pertain only to individual aggregate particles. The application of remote sensing and airborne geophysical measurements to detecting and mapping potential aggregate sources, however, is based on intrinsic bulk physical properties and extrinsic characteristics of the deposits that can be directly measured, mathematically derived from measurement, or interpreted with remote sensing and geophysical data. ?? 1995 Oxford UniversityPress.

  10. 76 FR 77782 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... resulted in schedule challenges that forced the survey into an inclement weather period and after further... echosounder (MBES) and a sub-bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e... these dates is possible, depending on logistics and weather. The proposed seismic survey will...

  11. The Unicorn Cave, Southern Harz Mountains, Germany: From known passages to unknown extensions with the help of geophysical surveys

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg; Nielbock, Ralf; Romanov, Douchko

    2015-12-01

    In soluble rocks (limestone, dolomite, anhydrite, gypsum, …), fissures and bedding partings can be enlarged with time by both physical and chemical dissolution of the host rock. With time, larger cavities evolve, and a network of cave passages can evolve. If the enlarged cave voids are not too deep under the surface, geophysical measurements can be used to detect, identify and trace these karst structures, e.g.: (i) gravity revealing air- and sediment-filled cave voids through negative Bouguer anomalies, (ii) electrical resistivity imaging (ERI) mapping different infillings of cavities either as high resistivities from air-filled voids or dry soft sediments, or low resistivities from saturated sediments, and (iii) groundwater flow through electrical potential differences (SP) arising from dislocated ionic charges from the walls of the underground flow paths. We have used gravity, ERI, and SP methods both in and above the Unicorn Cave located in the southern Harz Mountains in Germany. The Unicorn Cave is a show cave developed in the Werra dolomite formation of the Permian Zechstein sequence, characterised by large trunk passages interrupted by larger rooms. The overburden of the cave is only around 15 m, and passages are filled with sediments reaching infill thicknesses up to 40 m. We present results from our geophysical surveys above the known cave and its northern and southern extension, and from the cave interior. We identify the cave geometry and its infill from gravity and ERI measurements, predict previously unknown parts of the cave, and subsequently confirm the existence of these new passages through drilling. From the wealth of geophysical data acquired we derive a three-dimensional structural model of the Unicorn Cave and its surrounding, especially the cave infill.

  12. Spatial scale analysis in geophysics - Integrating surface and borehole geophysics in groundwater studies

    USGS Publications Warehouse

    Paillet, Frederick L.; Singhroy V.H.Hansen D.T.Pierce R, R

    2002-01-01

    Integration of geophysical data obtained at various scales can bridge the gap between localized data from boreholes and site-wide data from regional survey profiles. Specific approaches to such analysis include: 1) comparing geophysical measurements in boreholes with the same measurement made from the surface; 2) regressing geophysical data obtained in boreholes with water-sample data from screened intervals; 3) using multiple, physically independent measurements in boreholes to develop multivariate response models for surface geophysical surveys; 4) defining subsurface cell geometry for most effective survey inversion methods; and 5) making geophysical measurements in boreholes to serve as independent verification of geophysical interpretations. Integrated analysis of surface electromagnetic surveys and borehole geophysical logs at a study site in south Florida indicates that salinity of water in the surficial aquifers is controlled by a simple wedge of seawater intrusion along the coast and by a complex pattern of upward brine seepage from deeper aquifers throughout the study area. This interpretation was verified by drilling three additional test boreholes in carefully selected locations.

  13. Helicopter Electromagnetic and Magnetic Geophysical Survey Data, Oakland, Ashland, and Firth Study Areas, Eastern Nebraska, March 2007

    USGS Publications Warehouse

    Smith, Bruce D.; Abraham, Jared D.; Cannia, James C.; Steele, Gregory V.; Hill, Patricia L.

    2008-01-01

    This report is a digital data release for a helicopter electromagnetic and magnetic survey that was conducted during March 2007 in three 93-square-kilometer (36-square-mile) areas of eastern Nebraska as part of a joint State of Nebraska and U.S. Geological Survey study. The objective of the survey is to improve the understanding of the relationship between surface-water and ground-water systems critical to developing water resource management programs. The electromagnetic equipment consisted of six different coil-pair orientations that measured electrical resistivity at separate frequencies from about 400 hertz to about 115,000 hertz. The electromagnetic data were converted to electrical resistivity geo-referenced grids and maps, each representing different approximate depths of investigation for each area. The range of subsurface investigation is comparable to the depth of shallow aquifers. The three areas selected for the study, Ashland, Firth, and Oakland, have glacial terrains and bedrock that typify different hydrogeologic settings for surface water and ground water in eastern Nebraska. The geophysical and hydrologic information from U.S. Geological Survey studies are being used by resource managers to develop ground-water resource plans for the area.

  14. Imaging quadrupolar geophysical anomaly sources by 3D probability tomography: application to near-surface geoelectrical surveys

    NASA Astrophysics Data System (ADS)

    Alaia, Raffaele; Patella, Domenico; Mauriello, Paolo

    2008-12-01

    We present the theory of the source quadrupole occurrence probability tomography method within a general approach including the source pole and source dipole occurrence probability tomographies, developed and amply discussed and tested in previous papers. In this new formulation, poles and dipoles still have the original meaning to represent centres and boundaries, respectively, of elementary bodies with constant constitutive parameters, while quadrupoles are assumed to simulate sharp corner elements. The purpose of quadrupole analysis is to improve the resolution power of geophysical methods, using once more probability as a suitable paradigm allowing all possible equivalent solutions to be included into a unique 3D tomography image. The new approach is described by first assuming that any geophysical field dataset can be hypothesized to be caused by a discrete number of source poles, dipoles and quadrupoles. Then, the previously published theory of the source pole and dipole occurrence probability tomography is symbolically extended to include source quadrupoles. Finally, the new formalism is explicitly written for the geoelectrical method, for which a few simple synthetic examples are discussed in order to demonstrate how the combined pole, dipole and quadrupole tomographies can provide a complete resolution of the most probable buried sources of the anomalies detected within a datum domain. A field example related to a geoelectrical survey carried out in the archaeological park of Pompei is presented, aiming at detecting remains of ancient Roman urbanization.

  15. A large scale geophysical survey in the archaeological site of Europos (northern Greece)

    NASA Astrophysics Data System (ADS)

    Tsokas, G. N.; Giannopoulos, A.; Tsourlos, P.; Vargemezis, G.; Tealby, J. M.; Sarris, A.; Papazachos, C. B.; Savopoulou, T.

    1994-04-01

    The results of a large scale exploration of an archaeological site by geophysical means are presented and discussed. The operation took place in the site where the ruins of the ancient city of Europos are buried. This site is in northern Greece. Resistivity prospecting was employed to detect the remnants of wall foundations in the place where the main urban complex of the ancient city once stood. The data were transformed in an image form depicting, thus, the spatial variation of resistivity in a manner that resembles the plane view of the ruins that could have been drawn if an excavation had taken place. This image revealed the urban plan of the latest times of the life of the city. Trial excavations verified the geophysical result. Magnetic prospecting in the same area complemented the resistivity data. The exact location of the fire hearths, kilns and remnants of collapsed roofs were spotted. Magnetic gradient measurements were taken in an area out of the main complex of the ancient city and revealed the location of several kilns. One of these locations was excavated and a pottery kiln was discovered. The resistivity prospecting in one of the graveyards of the ancient city showed anomalies which were expected and corresponded to monumental tombs. The locations of a few of them were excavated and large burial structures were revealed. Ground probing radar profiles were measured over the tombs which showed pronounced resistivity anomalies, so far unearthed. The relatively high resolving ability of the method assisted the interpretation in the sense that a few attributes were added. In the presented case, it was concluded that a particular tomb consists of two rooms and that it is roofless.

  16. Geophysical Surveys for Detecting Anomalous Conditions, Algiers Canal Levees, New Orleans, Louisiana

    DTIC Science & Technology

    2014-08-01

    with grout. An electromagnetic (EM) induction survey using a Geonics EM31 terrain conductivity meter was conducted along the crest, slopes, and...other New Orleans levees, was the electromagnetic (EM) induction survey method. The general process employed for field data collection was to... Electromagnetic terrain conductivity measurements at low induction numbers. Technical Note TN-6. Mississauga, Ontario, Canada:Geonics Limited. Llopis, J

  17. 76 FR 49737 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... (MBES) and a sub-bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e..., depending on logistics and weather. The seismic survey will collect seismic reflection and refraction... overlying sediments. Acoustic velocities (required to convert measured travel times to true depth) will...

  18. 76 FR 20325 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ...-bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e., increased underwater... possible, depending on logistics, weather conditions, and the need to repeat some lines if data quality is... towed along the survey lines, the hydrophone streamers will receive the returning acoustic signals...

  19. 76 FR 26255 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ...) and a sub-bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e., increased... logistics and weather. The proposed seismic survey will collect seismic reflection and refraction data to... streamers will receive the returning acoustic signals and transfer the data to the on-board...

  20. 77 FR 6065 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... maintenance issues resulted in schedule challenges that forced the survey into an inclement weather period and... multibeam echosounder (MBES) and a sub-bottom profiler (SBP) continuously throughout the survey. Acoustic... 21, 2012. Some minor deviation from these dates is possible, depending on logistics and weather....

  1. 76 FR 33705 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-09

    ... echosounder (MBES) and a sub-bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e... deviation from these dates is possible, depending on logistics and weather. The seismic survey will collect... the thickness of the overlying sediments. Acoustic velocities (required to convert measured...

  2. 76 FR 33246 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... throughout the survey. Acoustic stimuli (i.e., increased underwater sound) generated during the operation of... logistics and weather. The proposed seismic survey will collect seismic reflection and refraction profiles... sediments. Acoustic velocities (required to convert measured travel times to true depth) will be...

  3. Integrated geophysical and LIDAR surveys at the archaeological site of Ancient Epomanduodurum, Mandeure-Mathay (Doubs, Eastern France).

    NASA Astrophysics Data System (ADS)

    Thivet, M.; Bossuet, G.; Laplaige, C.

    2009-04-01

    For several years, some integrated geophysical studies were carried out at Mandeure-Mathay (Franche-Comté Region, Eastern France) for the archaeological evaluation of ancient Epomanduodurum. It's a site of a major scientific interest for understanding the territorial structure of earliest agglomerations in the Eastern Gaul at the end of the Iron Age and during the Roman period. As regards its size, urban equipment, monuments and function, the ancient town is considered as the second behind the civitas capital of Sequani, Besançon-Vesontio. It is located in the Doubs valley, where the plain of Alsace opens into the marches of Burgundy, in a traffic zone between the Vosges and the Jura. This location allows transit between the Rhône valley and the Rhein plain, through Saône and Doubs valleys. This geographical situation was a significant factor in the creation of the late Iron Age settlement, later to turn into a major Gallo-roman town. The whole site includes urban centre and two artisan suburbs. The buried ruins are extended moreover 500 hectares outside and inside a meander of the river. The first "well-organized" research done on the site goes back as far as the end of the 18th Century. However, it is only round the beginning of the 19th century that major constructions such as the theatre (1820) and the sanctuary (1880) were uncovered. The status and the influence of Latenian sanctuary, located in the centre part of a great monumental complex of Early Augustan period, played probably an important role in the emergence of this foreground agglomeration. From the beginning of the survey, in 2001, high resolution and no invasive geophysical methods have been performed on large scale both on the terrace and in the floodplain. Automatic Resistivity Profiling (ARP) and magnetic mapping were taken in grids covering respective areas of 60 and 40 hectares. Ground penetrating radar was occasionally used to confirm the detection of specific anthropogenic anomalies

  4. Geophysical Survey and Detailed Geologic Mapping of an Eroded Stratovolcano's Central Intrusive Complex, Summer Coon, Co.

    NASA Astrophysics Data System (ADS)

    Harp, A.

    2015-12-01

    Eroded volcanoes expose plumbing systems that provide important information on intrusive geometries, magma propagation directions, and the effects of host rock types and heterogeneities. Summer Coon Volcano, CO, is an Oligocene stratovolcano where erosion has removed much of the original edifice, revealing the intrusive stocks of the central intrusive complex (CIC). Surrounding the CIC are hundreds of radial dikes ranging from basaltic to rhyolitic in composition. Published geologic maps indicate most radial dikes do not connect to the intrusive stocks, supporting published theories that most did not emanate from the central intrusions. However, much of the area surrounding the CIC is covered by alluvium, suggesting that the lack of connection might be an artifact of exposure. We completed a ground magnetic survey and detailed geological mapping to determine if the dikes continue beneath the alluvium and into the intrusive stocks. Linear magnetic anomalies indicate four NW-SE trending rhyodacite dikes continue beneath the alluvium for up to 250 m, and mapping indicates that at least two of the rhyodacite dikes do extend into the CIC. Shorter linear anomalies are attributed to seven NW-SE trending basaltic dikes ~100-500-m-long which are sparsely exposed in the alluvium. Mapping shows that three rhyodacite dikes extend into the CIC and to within 200 m of their possible source, an 800-m-wide granodiorite stock. Additionally, three rhyolitic dikes extend to within several meters of a 200×500-m-wide tuff breccia zone of similar composition, likely their source. In summary, magnetic data and detailed mapping indicate that radial dikes do extend into the central intrusive complex in contrast to some model predictions.

  5. Sustainable urban development and geophysics

    NASA Astrophysics Data System (ADS)

    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. 43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... are surveys of the physical characteristics of mineral deposits to measure physical differences... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  7. 43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... are surveys of the physical characteristics of mineral deposits to measure physical differences... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  8. 43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... are surveys of the physical characteristics of mineral deposits to measure physical differences... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  9. 43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... are surveys of the physical characteristics of mineral deposits to measure physical differences... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  10. Identifying Fossil Shell Resources via Geophysical Surveys: Chesapeake Bay Region, Virginia

    DTIC Science & Technology

    2016-05-01

    feasibility of using acoustic sub-bottom seismic surveys for determining the location and quantity of buried FOS. Over 280 miles of seismic surveys and...successfully identify buried FOS regions throughout the geologically complex study area. The acoustic nature of buried FOS is site specific, however, and...sediment, of which a minimum of ~288,000 ft3 is shell material. Although a purely quantitative assessment of acoustic data is possible, it is empirical and

  11. Geophysical survey, Paso Robles geothermal area, California, part of the resource assessment of low- and moderate-temperature geothermal resource areas in California

    SciTech Connect

    Chapman, R.H.; Chase, G.W.; Youngs, L.G.

    1980-11-10

    Some general background information concerning the geology and geothermal occurrences in the Southern Coast Ranges is included, as well as the more detailed information dealing with the Paso Robles area proper. Results for two geophysical methods that have been used in the area: the ground magnetic and gravity surveys, are discussed and interpreted.

  12. Basic exploration geophysics

    SciTech Connect

    Robinson, E.S.

    1988-01-01

    An introduction to geophysical methods used to explore for natural resources and to survey earth's geology is presented in this volume. It is suitable for second-and third-year undergraduate students majoring in geology or engineering and for professional engineering and for professional engineers and earth scientists without formal instruction in geophysics. The author assumes the reader is familiar with geometry, algebra, and trigonometry. Geophysical exploration includes seismic refraction and reflection surveying, electrical resistivity and electromagnetic field surveying, and geophysical well logging. Surveying operations are described in step-by-step procedures and are illustrated by practical examples. Computer-based methods of processing and interpreting data as well as geographical methods are introduced.

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

    SciTech Connect

    Fercho, Steven; Owens, Lara; Walsh, Patrick; Drakos, Peter; Martini, Brigette; Lewicki, Jennifer L.; Kennedy, Burton M.

    2015-08-01

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

  14. Additional borehole geophysical logging at Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1994-07-01

    This technical memorandum describes the borehole geophysical logging performed at selected coreholes at Waste Area Grouping 1 between March and November 1991 in support of the remedial investigation. The primary objectives of the borehole geophysical logging program were to (1) identify fractured bedrock zones and identify those fractured bedrock zones participating in active groundwater flow, (2) correlate the fractured intervals with the regional stratigraphy described, and (3) further characterize local bedrock geology and hydrogeology and gain insight about the bedrock aquifer flow system. A secondary objective was to provide stratigraphic correlations with existing logs for coreholes CH001 through CH005. Fractured bedrock zones and active or open fractures were identified in all coreholes logged. The fracture identification and analysis process was intended to distinguish between open or active fractures participating in active groundwater flow and closed or inactive fractures that are partially or completely filled (such as with calcite mineralization) and do not support groundwater circulation. Most of the fractures identified are bedding plane. Fracture occurrence varies with the different units of the Chickamauga Group; the greatest density of fractures and active fractures occurs in the upper 150 ft of stratum cored. Fractures actively contributing to groundwater flow were also identified, and direction of fluid movement within fractures was identified for those coreholes with flowmeter data.

  15. High spatial resolution observations of 137Cs in northern Britain and Ireland from airborne geophysical survey.

    PubMed

    Scheib, Cathy; Beamish, David

    2010-09-01

    This study reports the (137)Cs data derived from three regional and national scale High Resolution Airborne Resource and Environmental Surveys (HiRES) in northern Britain and Ireland. The detailed spatial resolution, combined with the large areas these surveys collectively cover, gives insight into large-scale deposition patterns and possible subsequent re-distribution of (137)Cs on a level that was previously not possible. The largest survey area considered covers the whole of Northern Ireland. All three data sets display some clustering of higher (137)Cs activities on high ground together with regional scale NNW-SSE and NW-SE banding features. We interpret these as representing a series of rainfall interceptions of the repeated passage of the Chernobyl plume. Our observations, obtained at 200 m flight line intervals, appear to provide significant detail in relation to existing knowledge of large scale along-wind deposition of (137)Cs.

  16. Contribution of the airborne geophysical survey to the study of the regolith : A case study in southern Paris Basin.

    NASA Astrophysics Data System (ADS)

    Prognon, Francois; Lacquement, Fréderic; Deparis, Jacques; Martelet, Guillaume; Perrin, José

    2010-05-01

    Studies of soil and subsoil, also called regolith, are at the crossroads of scientific new challenging questions as well as new environmental needs. Historically, geological maps were focussed on solid geology. Present societal needs increasingly require knowledge of regolith properties: superficial studies combining geology, geochemistry and geophysics become essential to better understand the natural processes which govern the repartition and evolution of subsoil formations. Such progress is critical to better orient the use and management of natural and groundwater resources. Among other techniques, airborne geophysics is appropriate to provide information on near surface, because of i) its high spatial coverage ii) the rapidity of acquisition and iii) the variety of available sensors (magnetic, spectral radiometry, electromagnetic …). We illustrate the results of an airborne geophysical survey carried out in France, in "Région Centre" administrative region in the southern part of the Paris Basin. Spectral radiometry data were collected throughout "Région Centre" with a line spacing of 1 km. This method provides maps of potassium (K), uranium (U) and thorium (Th) which are the only naturally occurring elements with direct or indirect radioisotopes that produce gamma rays of sufficient intensity to be measured at airborne survey heights. Gamma-rays emitted from the Earth surface are related to the primary mineralogy and geochemistry of the bedrock and/or the nature of secondary weathering including regolith materials. Obtained images are confronted with former geological investigations (1:50 000e geological maps). Geophysical data and geological maps are generally consistent on most of the covered area since the first-rate information delivered by the spectrometry derives from the geochemistry of the solid geology. Second-rate gamma-ray responses come from superimposed allochtonous deposits as well as in situ geochemical modifications. For instance

  17. LiDAR, geophysical and field surveys at Ancient Epomanduodurum site and its surrounding country (Doubs, Eastern France)

    NASA Astrophysics Data System (ADS)

    Laplaige, Clement; Bossuet, Gilles; Thivet, Matthieu

    2010-05-01

    Integrated geophysical studies were carried out over several years, at Mandeure-Mathay (Franche-Comté Region, Eastern France) for the archaeological evaluation of ancient Epomanduodurum. The site is of major scientific interest to understand the territorial structure of earlier agglomerations in Eastern Gaul at the end of the Iron Age and during the Roman period. As regards its size, urban equipment, monuments and function, the ancient town is considered rating second behind the civitas capital of Sequani, Besançon-Vesontio. It is located in the Doubs valley, where the plain of Alsace opens into the marches of Burgundy, in a traffic zone between the Vosges and the Jura. This location allows transit between the Rhône valley and the Rhein plain, through the Saône and Doubs valleys. This geographical situation was a significant factor in the creation of the late Iron Age settlement, later to turn into a major Gallo-roman town. The whole site of the Ancient town includes urban centre and two artisan suburbs. The buried ruins stretch on more than 500 hectares outside and inside a meander of the Doubs River. From the beginning of the survey, in 2001, high resolution and non invasive geophysical methods (magnetic mapping and Automatic Restivity Profiling (ARP) were performed on large scale, both on the terrace and in the floodplain). Excavations associated to geophysical prospection allow to produce a general plan of the Gallo roman structures and to reconstruct the settlement evolution. While human occupation on open land is certified by a lot of indications, on the contrary, the forest-covered zones on table-land appear as less documented areas. The explanation is that some of the classic methods (such as aerial reconnaissance and field walking) are less efficient in the archaeological prospection of table-lands and hills, naturally marked by omnipresent forest. In our new research program (LIEPPEC and PCR Mandeure, 2008-2010), it appears necessary to better

  18. Assessing subaqueous mudslide hazard on the Mississippi River delta front, Part 2: Insights revealed through high-resolution geophysical surveying

    NASA Astrophysics Data System (ADS)

    Obelcz, J.; Xu, K.; Bentley, S. J.; Georgiou, I. Y.; Maloney, J. M.; Miner, M. D.; Hanegan, K.; Keller, G.

    2014-12-01

    The northern Gulf of Mexico, including the subaqueous Mississippi River delta front (MRDF), has been productive for oil and gas development since the early 1900s. In 1969 cyclic seafloor wave loading associated with the passage of Hurricane Camille triggered subaqueous mudflows across the MRDF, destroying several offshore oil platforms. This incident spurred geophysical and geotechnical studies of the MRDF, which found that the delta front is prone to mass failures on gentle gradients (<0.5°) due to (1) high rates of fine-grained sedimentation and associated underconsolidation, (2) excess sediment pore pressure attributed to in-situ biogenic gas production, and (3) the frequent passage of tropical cyclones. In June 2014, a geophysical pilot study was conducted 8 km southwest of Southwest Pass, the distributary that currently receives the largest fraction of Mississippi River sediment supply. The resultant dataset encompasses 216 km of subbottom Chirp seismic profiles and a 60 km2 grid of bathymetry and sidescan data. Preliminary interpretation of these data shows the survey area can be classified into four primary sedimentary facies: mudflow gullies, mudflow lobes, undisturbed prodelta, and undisturbed delta front. Subbottom profiles reveal extensive biogenic gas from 20 to about 80 m water depths on the delta front; sidescan data show a variety of bottleneck slides, mudflow gullies and mudflow noses. Previous studies have attempted to constrain the periodicity and magnitude of subaqueous mudslides on the MRDF. However, large age gaps and varied resolution between datasets result in ambiguity regarding the cause and magnitude of observed bathymetric changes. We present high-temporal resolution MRDF bathymetric variations from 2005 (post Hurricane Katrina), 2009 (relatively quiescent storm period), and 2014 (post 2011 Mississippi River flood). These data yield better magnitude and timing estimates of mass movements. This exercise represents a first step towards (1

  19. Results from the Air Force Geophysics Laboratory survey catalog. [IR astronomy

    NASA Technical Reports Server (NTRS)

    Price, S. D.; Walker, R. G.

    1977-01-01

    Results of an IR survey program designed to obtain the spatial and brightness distributions of a representative sample of IR-emitting objects in the 3-30 micron range are analyzed. Small cryogenically cooled telescopes carried above the atmosphere on sounding rockets were employed in the research. Minimization of sky noise and photon background, experimental equipment, and data reduction techniques are discussed.

  20. 75 FR 44770 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-29

    ... echosounder (MBES) and a sub-bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e... logistics, weather conditions, and the need to repeat some lines if data quality is substandard. Therefore... streamers will receive the returning acoustic signals and transfer the data to the vessel's...

  1. 76 FR 6430 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ... echosounder (MBES) and a sub-bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e... deviation from these dates is possible, depending on logistics, weather conditions, and the need to repeat... receive the returning acoustic signals and transfer the data to the on-board processing system. L-DEO...

  2. 76 FR 57959 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ...- bottom profiler (SBP) continuously throughout the survey. Acoustic stimuli (i.e., increased underwater... possible, depending on logistics, weather conditions, and the need to repeat some lines if data quality is... receive the returning acoustic signals and transfer the data to the on-board processing system. The...

  3. 77 FR 56613 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    ..., and an acoustic Doppler current profiler continuously throughout the survey except while on station for marine coring activities. Acoustic stimuli (i.e., increased underwater sound) generated during... for a more detailed description of the authorized action, including vessel and acoustic...

  4. 75 FR 28568 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... throughout the survey. Acoustic stimuli (i.e., increased underwater sound) generated during the operation of... possible, depending on logistics, weather conditions, and the need to repeat some lines if data quality is... lines, the hydrophone streamers will receive the returning acoustic signals and transfer the data to...

  5. Geophysical Surveys for Locating Buried Utilities, Lake Pontchartrain Levees, New Orleans

    DTIC Science & Technology

    2014-06-01

    Drive and Topaz Street. It is an urbanized area that has a great deal of metallic clutter that interfered with the EM31. The survey areas within...with Topaz Street to the west bank of the Orleans Avenue Canal. The site is divided into five sections designated LPV102_A through LPV102_E for

  6. 75 FR 8652 - Incidental Takes of Marine Mammals During Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

    ... Pacific plate. The objective is to understand the water cycle within subduction-systems. Subduction....S. The survey will take place in the Exclusive Economic Zone (EEZ) of the U.S. in water depths... earthquakes occur. Little is known about either of these processes, but water cycling through the system...

  7. 78 FR 34069 - Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... National Science Foundation (NSF) (which owns the R/V Marcus G. Langseth) and L-DEO (which operates the R/V... Science Foundation. As the airgun array is towed along the survey lines, the hydrophone streamers would... and OBHs record the returning acoustic signals internally for later analysis. A total of...

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

    USGS Publications Warehouse

    Taylor, Cliff D.

    2003-01-01

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

  9. 3D Subsoil Model of the San Biagio `Salinelle' Mud Volcanoes (Belpasso, Sicily) derived from Geophysical Surveys

    NASA Astrophysics Data System (ADS)

    Imposa, S.; Grassi, S.; De Guidi, G.; Battaglia, F.; Lanaia, G.; Scudero, S.

    2016-11-01

    Mud volcanoes are common in active mountain fronts. At Mt. Etna, located just between the Apennine front in Sicily and its foredeep, there are some manifestations of mud volcanism in the lower border of the volcanic edifice. The activity of these mud volcanoes is characterized by persistent emission of muddy water mixed with salts, which rises to the surface due to the gas pressure in the subsoil. The San Biagio Salinelle is one of the three mud volcano fields located around the Paternò eruptive monogenic apparatus; this old volcanic structure was one of the first subaerial volcanic manifestations that formed in the pre-Etnean phase. It is not fully clear whether and how the activity of the mud fields is connected with the volcanic activity of Mt. Etna. Noninvasive geophysical surveys were carried out in the area of the active cone of the San Biagio Salinelle, in order to identify the probable ascent path of the emitted products. Seismic ambient noise records were collected at the nodes of a specially designed grid and, subsequently, the V s values were obtained from an active seismic survey. A digital elevation model (DEM) of the area was obtained by a topographic survey, carried out with the GNSS technique (global navigation satellite system), in real-time kinematic mode. The DEM and the topographic benchmark installed will represent the reference surface for future periodic monitoring of the ongoing deformation in the area. Our results provide an accurate and detailed 3D subsurface model showing the shallower feeding system of the investigated mud volcano.

  10. Pilot CCS project in Indonesia "Gundih CCS project": Geological and geophysical surveys for site selection and monitoring

    NASA Astrophysics Data System (ADS)

    Tsuji, Takeshi; Matsuoka, Toshifumi; Takahashi, Toru; Kitamura, Keigo; Onishi, Kyosuke; Yamada, Yasuhiro; Rachmat Sule, Mohammad; Kadir, Wawan Gunawan A.; Widarto, Djedi S.; Sebayang, Rio I.; Prasetyo, Agung; Priyono, Awali; Widianto, Eko; Sapiie, Benyamin

    2013-04-01

    A pilot CCS project in Indonesia will be implemented in Gundih area, Central Java Province. The Gundih area is a gas field, and gas is ready to be produced by Pertamina EP. The CO2 content within the produced gas is more than 20% in the Gundih field, so that CO2 injection near the gas production well could be effective way to avoid abundant CO2 emission. Before implementing CO2 injection, the reservoir for CO2 injection must be characterized carefully by conducting subsurface characterization and evaluation, in order to make sure that the reservoir is suitable for CCS. Here we report preliminary results of site surveys for the determination of CO2 injection site in the Gundih area. Subsurface structures imaged on seismic reflection profiles indicate that the Ngrayong formation is one of the candidates for CO2 injection. The lithology of the Ngrayong formation is sandstone, and the depth of the formation is ~1 km in the Gundih area. Since we could not find large-scale structural closure (i.e., anticline) for the Ngrayong formation, we need to consider residual trapping. To reveal hydrological properties (e.g., permeability) of the Ngrayong formation, we obtained rock samples from the outcrop of the Ngrayong formation. Using the laboratory-derived hydrological properties and subsurface structures extracted from seismic data (e.g., geometry of the Ngrayong formation), we will apply reservoir simulation in order to determine CO2 injection site. To design the geophysical monitoring survey (e.g., receiver and source position in time-lapse seismic survey), furthermore, we conduct simulation study for the constructed geological model and estimate elastic and electric responses associated with CO2 injection.

  11. Remote Operated Vehicle geophysical surveys on land (underground), air and submarine archaeology: General peculiarities of processing and interpretation

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev

    2016-04-01

    The last Remote Operation Vehicles (ROV) generation - small and maneuvering vehicles with different geophysical sensors - can fly at levels of a few meters (and even tens of centimeters) over the earth's surface, to move on the earth's surface and in the inaccessible underground areas and to explore in underwater investigations (e.g., Mindel and Bingham, 2001; Rowlands and Sarris, 2006; Wilson et al., 2006; Rigaud, 2007; Eppelbaum, 2008; Patterson and Brescia, 2008; Sarris, 2008; Wang et al., 2009; Wu and Tian, 2010; Stall, 2011; Tezkan et al., 2011; Winn et al., 2012; El-Nahhas, 2013; Hadjimitsis et al., 2013; Hajiyev and Vural, 2013; Hugenholtz et al., 2013; Petzke et al., 2013; Pourier et al., 2013; Casana et al., 2014; Silverberg and Bieber, 2014). Such geophysical investigations should have an extremely low exploitation cost and can observe surface practically inaccessible archaeological sites (swampy areas, dense vegetation, rugged relief, over the areas of world recognized religious and cultural artifacts (Eppelbaum, 2010), etc.). Finally, measurements of geophysical fields at different observation levels could provide a new unique geological-geophysical information (Eppelbaum and Mishne, 2011). Let's consider ROV airborne magnetic measurements as example. The modern magnetometric equipment enables to carry out magnetic measurements with a frequency of 50 times per second (and more) that taking into account the low ROV flight speed provides a necessary density of observations. For instance, frequency of observation of 50 times per second by ROV velocity of 40 km/hour gives density of observation about 0.2 m. It is obvious that the calculated step between observation points is more than sufficient one. Such observations will allow not only reduce the influence of some small artificial sources of noise, but also to obtain some additional data necessary for quantitative analysis (some interpretation methodologies need to have observations at two levels; upward

  12. Jupiter's and Saturn's ice moons: geophysical aspects and opportunities of geophysical survey of the planetary geoelectrical markers and oreols of the subsurface liquid ocean on the surface ice moons

    NASA Astrophysics Data System (ADS)

    Ozorovich, Yuri; Linkin, Vacheslav; Kosov, Alexandr; Fournier-Sicre, Alain; Klimov, Stanislav; Novikov, Denis; Ivanov, Anton; Skulachev, Dmitriy; Menshenin, Yaroslav

    2016-04-01

    This paper presents a new conceptual and methodological approach for geophysical survey of the planetary geoelectrical markers and oreols of the subsurface liquid ocean on the surface ice moons on the base "conceptual design phase" of the future space missions on the ice moons. At the design stage of such projects is considered the use of various space instruments and tools for the full the complex geophysical studies of the manifestations and planetary processes of the subsurface liquid ocean on the surface ice moons. The existence of various forms of the cryolithozone on terrestrial planets and their moons: advanced Martian permafrost zone in the form of existing of the frozen polar caps, subsurface frozen horizons, geological markers and oreols of the martian ancient (relict) ocean, subsurface oceans of Jupiter's and Saturn's moons-Europe and Enceladus, with the advanced form of permafrost freezes planetary caps, it allows to develop a common methodological basis and operational geophysical instruments (tools) for the future space program and planning space missions on these unique objects of the solar system, specialized for specific scientific problems of planetary missions. Geophysical practices and methodological principles, used in 1985-2015 by aurthors [ 1-5 ], respectively, as an example of the comprehensive geophysical experiment MARSES to study of the Martian permafrost zone and the martian ancient (relict) ocean, creating the preconditions for complex experimental setting and geo-physical monitoring of operational satellites of Jupiter and Saturn- Europe and Enceladus. This range of different planetary (like) planets with its geological history and prehistory of the common planetology formation processes of the planets formation and to define the role of a liquid ocean under the ice as a climate indicator of such planets, which is extremely important for the future construction of the geological and climatic history of the Earth. Main publications: [1

  13. Environmental and Engineering Geophysics

    NASA Astrophysics Data System (ADS)

    Sharma, Prem V.

    1997-12-01

    Geophysical imaging methods provide solutions to a wide variety of environmental and engineering problems: protection of soil and groundwater from contamination; disposal of chemical and nuclear waste; geotechnical site testing; landslide and ground subsidence hazard detection; location of archaeological artifacts. This book comprehensively describes the theory, data acquisition and interpretation of all of the principal techniques of geophysical surveying: gravity, magnetic, seismic, self-potential, resistivity, induced polarization, electromagnetic, ground-probing radar, radioactivity, geothermal, and geophysical borehole logging. Each chapter is supported by a large number of richly illustrated case histories. This book will prove to be a valuable textbook for senior undergraduates and postgraduates in environmental and applied geophysics, a supplementary course book for students of geology, engineering geophysics, civil and mining engineering, and a reference work for professional earth scientists, engineers and town planners.

  14. Gpr and Seismic Based Non-Destructive Geophysical Survey for Reinforcement of Historical Fire Tower of Sopron-Hungary

    NASA Astrophysics Data System (ADS)

    Kanli, A. I.; Taller, G.; Nagy, P.; Tildy, P.; Pronay, Z.; Toros, E.

    2013-12-01

    The Fire-Tower which is located in the main square at the hearth of Sopron is the symbol of the city. The museum of Sopron exists in the Storno-house west from the tower. The new city hall stands next to the tower to the east. Funds are from the roman age while the tower was first mentioned in writing in 1409. In 1676, it was burned down to the ground, but re-constructed. In 1894, the old City Hall was deconstucted, but the tower became unstable. István Kiss and Frigyes Schulek saved it by the walling up of the gate. In the year 1928, the scuptures of the main gate which symbolizes the fidelity of the town was sculpted by Zsigmond Kisfaludy Strobl. The old building was deconstructed from its west side, a new concrate museum was built in 1970. After years, important renovation and reinforcement studies had to be needed. For this aim, during the renovation and reinforcement studies, GPR and Seismic based non-destructive geophysical surveys were carried out before and after cement injection to observe the changes of the wall conditions of the historical tower located in Sopron-Hungary for understanding the success of the reinforcements studies. In the GPR survey, 400 MHz and 900 MHz antennas were used. The space between each profiles were taken as 0.5 m for 400 MHz and 0.25m for 900 MHz respectively. After the injection process, reflections from the fractured and porous zones were weakened imaged clearly by GPR data and significant rise of the p-wave velocities were observed.

  15. Integrated geophysical survey in defining subsidence features on a golf course

    NASA Astrophysics Data System (ADS)

    Xia, Jianghai; Miller, Richard D.

    2007-12-01

    Subsidence was observed at several places on the Salina Municipal Golf Course in areas known to be built over a landfill in Salina, Kansas. High-resolution magnetic survey (~5400 m2), multi-channel electrical resistivity profiling (three 154 m lines) and microgravity profiling (23 gravity-station values) were performed on a subsidence site (Green 16) to aid in determining boundaries and density deficiency of the landfill in the vicinity of the subsidence. Horizontal boundaries of the landfill were confidently defined by both magnetic anomalies and the pseudo-vertical gradient of total field magnetic anomalies. Furthermore, the pseudo-vertical gradient of magnetic anomalies presented a unique anomaly at Green 16, which provided a criterion for predicting other spots with subsidence potential using the same gradient property. Results of multi-channel electrical resistivity profiling (ERP) suggested the bottom limit of the landfill at Green 16 was around 21 m below the ground surface based on the vertical gradient of electric resistivity and a priori information on the depth of the landfill. ERP results also outlined several possible landfill bodies based on their low resistivity values. Microgravity results suggested a -0.14 g cm-3 density deficiency at Green 16 that could equate to future surface subsidence of as much as 1.5 m due to gradual compaction.

  16. Geophysical survey of the Eggvin Bank and Logi Ridge - Greenland Sea

    NASA Astrophysics Data System (ADS)

    Breivik, A. J.; Mjelde, R.; Rai, A. K.; Frassetto, A.

    2012-12-01

    The northern Greenland Sea has a number of features associated with excess volcanism. These include the Jan Mayen island, the Jan Mayen Plateau north of, and the Eggvin Bank west of Jan Mayen, and the Vesteris Seamount far to the north. In the summer of 2011, we colleced an Ocean Bottom Seismometer (OBS) profile across the Eggvin Bank, returning four good data sets. We also collected single-channel reflection seismic (SCS) data along the OBS line. The profile crosses the transform part of the West Jan Mayen Fracture Zone (WJMFZ), which connects seafloor spreading between the Kolbeinsey and Mohn ridges. Between the WJMFZ and the Vesteris Seamount there is a narrow ridge 170-180 km long, ending in a few seamounts in the east. It disturbs the magnetic seafloor anomalies, and has no conjugate on the Norwegian margin. It thus appears to be younger than the Eocene seafloor it lies on. Trend and position points to Traill Ø in East Greenland, which had magmatism at ~36 Ma. We name it the Logi Ridge after Norse mythology, where Logi is the master of fire, brother of Aegir, master of the sea. We have collected five SCS profiles across this ridge in order to study the surrounding sedimentation pattern. We also collected gravity and magnetic data along all profiles. Initial results show two flat-topped seamounts on the Eggvin Bank, and a flat-topped Logi Ridge, indicating that these have been at sealevel. The sedimentary strata show recent vertical movement north of the WJMFZ near the Jan Mayen Plateau, and compression around the Logi Ridge. Sailing line of R/V Håkon Mosby of Bergen. Survey lines are in bold, and OBS positions are marked by circles.

  17. An integrated geophysical survey of Kilbourne Hole, southern New Mexico: Implications for near surface exploration of Mars and the Moon

    NASA Astrophysics Data System (ADS)

    Maksim, Nisa

    Features such as the Home Plate plateau on Mars, a suspected remnant of an ancient phreatomagmatic eruption, can reveal important information about paleohydrologic conditions. The eruption intensity of a phreatomagmatic volcano is controlled mainly by the quantity of water and magma, the internal geometry of the volcano, and the depth of the interaction zone between magma and water. In order to understand the paleohydrologic conditions at the time of eruption, we must understand all the factors that influenced the phreatomagmatic event. I conducted an integrated geophysical survey, which are magnetic and gravity surveys, and a ground-penetrating radar (GPR) surveys at Kilbourne Hole, a phreatomagmatic crater in southern New Mexico. These investigations serve an analog paleo-hydrogeological study that could be conducted on Mars and the Moon with an implication for planetary exploration. These geophysical surveys are designed to delineate the internal structure of a phreatomagmatic volcano and to define the volumes and masses of volcanic dikes and excavation unit, the depth of feeder dikes, and impacted velocity of the volcanic blocks. For the gravity and magnetic surveys at Kilbourne Hole, I collected data at a total of 171 gravity survey stations and 166 magnetics survey stations. A 2D gravity and magnetic inverse model was developed jointly to map the body of the magma intrusions and the internal structure of Kilbourne Hole. A total of 6 GPR surveys lines were also completed at Kilbourne Hole to image and to define locations of pyroclastic deposits, volcanic sags and blocks, the sizes distribution of volcanic blocks, and the impact velocity of the volcanic blocks. Using the size distribution and impact velocity of volcanic blocks from our GPR data, I derived the initial gas expansion velocity and the time duration of the gas expansion phase of the Kilbourne Hole eruption. These obtained parameters (volumes, masses, and depths of the feeder dikes and the excavation

  18. A Geophysical Survey of the Quaternary Beatty Junction Paleolake Shoreline Deposit, Death Valley National Park, California

    NASA Astrophysics Data System (ADS)

    Craig, M.; Warnke, D.; Teitler, L.; Narvaez, R.

    2005-12-01

    We conducted a ground-penetrating radar (GPR) and seismic refraction survey of the Beatty Junction Shoreline Deposit in Death Valley National Park in March 2005. The deposit is a beach barrier bar approximately 500 m long, 50 m wide, and 5 m high, at an elevation of about 30 m above sea level and corresponds to a relict shoreline of the former Lake Manly (Orme and Orme, Phys. Geog., 12, pp. 334-346, 1980). The bar is oriented WSW-ENE, slopes to the east and is cut by the Beatty Junction Road. The longitudinal profile of the bar slopes to the east and is slightly concave upward. A total of 730 m of GPR data were recorded, including a longitudinal line 360 m in length, oriented along the crest of the bar, and four transverse lines, each approximately 100 m long. A hammer seismic refraction line was also recorded along the crest of the bar, and yielded a 3-layer model consisting of a surface layer about 1 m thick with a velocity of 200 m/s, a second layer 4-9 m thick with a velocity of 700 m/s, and a basal unit with a velocity of 1500 m/s. The uppermost layer apparently corresponds to an unconsolidated surface veneer of coarse gravel that has been winnowed to form desert pavement. The second layer is presumably sand and gravel that forms the main portion of the bar, and which thins in the longitudinal direction, from 9 m in the west to 4 m in the east. The third, basal layer represents older, more consolidated fan sediments. Shallow reflectors on the lakeward side of two of the transverse GPR lines have a distinct step-like appearance that may represent berms. All GPR lines show a thin surface layer, about 1 m thick, that unconformably covers all reflectors in the interior of the deposit, similar to the Hanaupah Shoreline Deposit at Tule Spring, described by Ibbeken and Warnke ( J. Paleolimnology, 23, pp. 439-447, 2002). The age of the deposit is given as 153 ± 12 Ka, late in Marine Isotope Stage 6 (Orme and Orme, 1991). Since this age range overlaps with that given

  19. 5 CFR 532.315 - Additional survey jobs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...: Specialized industry Specialized survey jobs Grade Aircraft Electronics Mechanic WG-11 Aircraft Structures... Electronics Electronics Mechanic WG-11 Industrial Electronic Controls Repairer WG-10 Electronic Test Equipment... Equipment Mechanic WG-10 Shipbuilding Electronics Mechanic WG-11 Electrician, Ship WG-10 Pipefitter, Ship...

  20. 5 CFR 532.315 - Additional survey jobs.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...: Specialized industry Specialized survey jobs Grade Aircraft Electronics Mechanic WG-11 Aircraft Structures... Electronics Electronics Mechanic WG-11 Industrial Electronic Controls Repairer WG-10 Electronic Test Equipment... Equipment Mechanic WG-10 Shipbuilding Electronics Mechanic WG-11 Electrician, Ship WG-10 Pipefitter, Ship...

  1. 5 CFR 532.315 - Additional survey jobs.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...: Specialized industry Specialized survey jobs Grade Aircraft Electronics Mechanic WG-11 Aircraft Structures... Electronics Electronics Mechanic WG-11 Industrial Electronic Controls Repairer WG-10 Electronic Test Equipment... Equipment Mechanic WG-10 Shipbuilding Electronics Mechanic WG-11 Electrician, Ship WG-10 Pipefitter, Ship...

  2. 5 CFR 532.315 - Additional survey jobs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: Specialized industry Specialized survey jobs Grade Aircraft Electronics Mechanic WG-11 Aircraft Structures... Electronics Electronics Mechanic WG-11 Industrial Electronic Controls Repairer WG-10 Electronic Test Equipment... Equipment Mechanic WG-10 Shipbuilding Electronics Mechanic WG-11 Electrician, Ship WG-10 Pipefitter, Ship...

  3. 5 CFR 532.315 - Additional survey jobs.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: Specialized industry Specialized survey jobs Grade Aircraft Electronics Mechanic WG-11 Aircraft Structures... Electronics Electronics Mechanic WG-11 Industrial Electronic Controls Repairer WG-10 Electronic Test Equipment... Equipment Mechanic WG-10 Shipbuilding Electronics Mechanic WG-11 Electrician, Ship WG-10 Pipefitter, Ship...

  4. Evaluation of geophysical logs and video surveys in boreholes adjacent to the Berkley Products Superfund Site, West Cocalico Township, Lancaster County, Pennsylvania

    USGS Publications Warehouse

    Low, Dennis J.; Conger, Randall W.

    1998-01-01

    Between February 1998 and April 1998, geophysical logs were collected in nine boreholes adjacent to the Berkley Products Superfund Site, West Cocalico Township, Lancaster County, Pa. Video surveys were conducted on four of the nine boreholes. The boreholes range in depth from 320 to 508 feet below land surface, are completed open holes, have ambient vertical flow of water, and penetrate a series of interbedded siltstone, sandstone, and conglomerate units. The purpose of collecting geophysical-log data was to help determine horizontal and vertical distribution of contaminated ground water migrating from known or suspected sources and to aid in the placement of permanent borehole packers. The primary contaminants were derived from paint waste that included pigment sludges and wash solvents. The chlorinated volatile organic compounds probably originated from the wash solvents. Caliper logs and video surveys were used to locate fractures; inflections on fluid-resistivity and fluid-temperature logs were used to locate possible water-bearing fractures. Heatpulse-flowmeter measurements were used to verify the locations of water-producing or water-receiving zones and to measure rates of flow between water-bearing fractures. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video surveys, and driller's logs, permanent multiple-packer systems were installed in each borehole to obtain depth specific water samples from one or more water-bearing fractures in each borehole.

  5. Late Quaternary activity along the Ferrara thrust inferred from stratigraphic architecture and geophysical surveys

    NASA Astrophysics Data System (ADS)

    Stefani, Marco; Bignardi, Samuel; Caputo, Riccardo; Minarelli, Luca; Abu-Zeid, Nasser; Santarato, Giovanni

    2010-05-01

    Since Late Miocene, the Emilia-Romagna portion of the Po Plain-Adriatic foredeep basin was progressively affected by compressional deformation, due to the northward propagation of the Apennines fold-and-thrust belt. The major tectonic structures within the basin have been recognised and are relatively well known, thanks to the widespread, even if outdated, seismic survey, performed after WW II, for hydrocarbon exploration. More recently, a large amount of surface and shallow-subsurface information has been provided by the CARG geological mapping project. The region therefore provides a valuable opportunity to discuss the genetic relationship between tectonic deformation, eustatic-paleoclimatic fluctuations, and depositional architecture. The activity of blind thrusts and fault-propagation folds induced repeated angular unconformities and impressive lateral variations in the Pliocene-Quaternary stratigraphy, causing thickness changes, from a few metres, close to the Apennines piedmont line, to more than 9 km, in fast subsiding depocenters (e.g. Lido di Savio). In the Ferrara region, the post-Miocene succession ranges from about 4 km, west of Sant'Agostino, to less than 200 m, on the Casaglia anticline, where Late Quaternary fluvial strata rest on Miocene marine marls, with an angular unconformity relationship. In this sector of the Po Plain, the tip-line of the northernmost thrust has been reconstructed north of the Po River (Occhiobello) and is associated with the growth of a large fold (Ferrara-Casaglia anticline), cross-cut by a complex splay of minor backthrusts and reverse faults. The thrust-anticline structure hosts an energy producing geothermal field, whose hydrogeological behaviour is largely influenced by the fracture pattern. The Apennines frontal thrust probably provided the seismic source for the earthquakes that severely damaged Ferrara, during the 1570 a.D. fall season, as documented by the structural damage still visible in many historic buildings (e

  6. 46 CFR 42.09-30 - Additional survey requirements for steel-hull vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Additional survey requirements for steel-hull vessels. 42.09-30 Section 42.09-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD...-30 Additional survey requirements for steel-hull vessels. (a) In addition to the requirements in §...

  7. 46 CFR 42.09-30 - Additional survey requirements for steel-hull vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Additional survey requirements for steel-hull vessels. 42.09-30 Section 42.09-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD...-30 Additional survey requirements for steel-hull vessels. (a) In addition to the requirements in §...

  8. 46 CFR 42.09-30 - Additional survey requirements for steel-hull vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Additional survey requirements for steel-hull vessels. 42.09-30 Section 42.09-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD...-30 Additional survey requirements for steel-hull vessels. (a) In addition to the requirements in §...

  9. 46 CFR 42.09-30 - Additional survey requirements for steel-hull vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Additional survey requirements for steel-hull vessels. 42.09-30 Section 42.09-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD...-30 Additional survey requirements for steel-hull vessels. (a) In addition to the requirements in §...

  10. 46 CFR 42.09-30 - Additional survey requirements for steel-hull vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Additional survey requirements for steel-hull vessels. 42.09-30 Section 42.09-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD...-30 Additional survey requirements for steel-hull vessels. (a) In addition to the requirements in §...

  11. 46 CFR 42.09-35 - Additional survey requirements for wood-hull vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Additional survey requirements for wood-hull vessels. 42.09-35 Section 42.09-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES... Additional survey requirements for wood-hull vessels. (a) In addition to the requirements in § 42.09-25,...

  12. 46 CFR 42.09-35 - Additional survey requirements for wood-hull vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Additional survey requirements for wood-hull vessels. 42.09-35 Section 42.09-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES... Additional survey requirements for wood-hull vessels. (a) In addition to the requirements in § 42.09-25,...

  13. 46 CFR 42.09-35 - Additional survey requirements for wood-hull vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Additional survey requirements for wood-hull vessels. 42.09-35 Section 42.09-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES... Additional survey requirements for wood-hull vessels. (a) In addition to the requirements in § 42.09-25,...

  14. 46 CFR 42.09-35 - Additional survey requirements for wood-hull vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Additional survey requirements for wood-hull vessels. 42.09-35 Section 42.09-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES... Additional survey requirements for wood-hull vessels. (a) In addition to the requirements in § 42.09-25,...

  15. 46 CFR 42.09-35 - Additional survey requirements for wood-hull vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Additional survey requirements for wood-hull vessels. 42.09-35 Section 42.09-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES... Additional survey requirements for wood-hull vessels. (a) In addition to the requirements in § 42.09-25,...

  16. Asymmetrical structure, hydrothermal system and edifice stability: The case of Ubinas volcano, Peru, revealed by geophysical surveys

    NASA Astrophysics Data System (ADS)

    Gonzales, Katherine; Finizola, Anthony; Lénat, Jean-François; Macedo, Orlando; Ramos, Domingo; Thouret, Jean-Claude; Fournier, Nicolas; Cruz, Vicentina; Pistre, Karine

    2014-04-01

    Ubinas volcano, the historically most active volcano in Peru straddles a low-relief high plateau and the flank of a steep valley. A multidisciplinary geophysical study has been performed to investigate the internal structure and the fluids flow within the edifice. We conducted 10 self-potential (SP) radial (from summit to base) profiles, 15 audio magnetotelluric (AMT) soundings on the west flank and a detailed survey of SP and soil temperature measurements on the summit caldera floor. The typical “V” shape of the SP radial profiles has been interpreted as the result of a hydrothermal zone superimposed on a hydrogeological zone in the upper parts of the edifice, and depicts a sub-circular SP positive anomaly, about 6 km in diameter. The latter is centred on the summit, and is characterised by a larger extension on the western flank located on the low-relief high plateau. The AMT resistivity model shows the presence of a conductive body beneath the summit at a depth comparable to that of the bottom of the inner south crater in the present-day caldera, where intense hydrothermal manifestations occur. The lack of SP and temperature anomalies on the present caldera floor suggests a self-sealed hydrothermal system, where the inner south crater acts as a pressure release valve. Although no resistivity data exists on the eastern flank, we presume, based on the asymmetry of the basement topography, and the amplitude of SP anomalies on the east flank, which are approximately five fold that on the west flank, that gravitational flow of hydrothermal fluids may occur towards the deep valley of Ubinas. This hypothesis, supported by the presence of hot springs and faults on the eastern foot of the edifice, reinforces the idea that a large part of the southeast flank of the Ubinas volcano may be altered by hydrothermal activity and will tend to be less stable. One of the major findings that stems from this study is that the slope of the basement on which a volcano has grown

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

    SciTech Connect

    Koppenjan, S,; Martinez, M.

    1994-06-01

    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.

  18. Sourcebook of locations of geophysical surveys in tunnels and horizontal holes, including results of seismic refraction surveys, Rainier Mesa, Aqueduct Mesa, and Area 16, Nevada Test Site

    USGS Publications Warehouse

    Carroll, R.D.; Kibler, J.E.

    1983-01-01

    Seismic refraction surveys have been obtained sporadically in tunnels in zeolitized tuff at the Nevada Test Site since the late 1950's. Commencing in 1967 and continuing to date (1982), .extensive measurements of shear- and compressional-wave velocities have been made in five tunnel complexes in Rainier and Aqueduct Mesas and in one tunnel complex in Shoshone Mountain. The results of these surveys to 1980 are compiled in this report. In addition, extensive horizontal drilling was initiated in 1967 in connection with geologic exploration in these tunnel complexes for sites for nuclear weapons tests. Seismic and electrical surveys were conducted in the majority of these holes. The type and location of these tunnel and borehole surveys are indexed in this report. Synthesis of the seismic refraction data indicates a mean compressional-wave velocity near the nuclear device point (WP) of 23 tunnel events of 2,430 m/s (7,970 f/s) with a range of 1,846-2,753 m/s (6,060-9,030 f/s). The mean shear-wave velocity of 17 tunnel events is 1,276 m/s (4,190 f/s) with a range of 1,140-1,392 m/s (3,740-4,570 f/s). Experience indicates that these velocity variations are due chiefly to the extent of fracturing and (or) the presence of partially saturated rock in the region of the survey.

  19. High-resolution geophysical data collected aboard the U.S. Geological Survey research vessel Rafael to supplement existing datasets from Buzzards Bay and Vineyard Sound, Massachusetts

    USGS Publications Warehouse

    Pendleton, Elizabeth A.; Andrews, Brian D.; Danforth, William W.; Foster, David S.

    2014-01-01

    Geophysical and geospatial data were collected in Buzzards Bay, in the shallow-water areas of Vineyard Sound, and in the nearshore areas off the eastern Elizabeth Islands and northern coast of Martha's Vineyard, Massachusetts, on the U.S. Geological Survey research vessel Rafael between 2007 and 2011, in a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management. This report describes results of this collaborative effort, which include mapping the geology of the inner shelf zone of the Elizabeth Islands and the sand shoals of Vineyard Sound and studying geologic processes that contribute to the evolution of this area. Data collected during these surveys include: bathymetry, acoustic backscatter, seismic-reflection profiles, sound velocity profiles, and navigation. The long-term goals of this project are (1) to provide high-resolution geophysical data that will support research on the influence of sea-level change and sediment supply on coastal evolution and (2) to inventory subtidal marine habitats and their distribution within the coastal zone of Massachusetts.

  20. The Chicxulub Multiring Impact Crater and the Cretaceous/Paleogene Boundary: Results From Geophysical Surveys and Drilling

    NASA Astrophysics Data System (ADS)

    Urrutia-Fucugauchi, J.; Perez-Cruz, Ligia

    2010-03-01

    The Chicxulub crater has attracted considerable attention as one of the three largest terrestrial impact structures and its association with the Cretaceous/Paleogene boundary (K/Pg). Chicxulub is a 200 km-diameter multi-ring structure formed 65.5 Ma ago in the Yucatan carbonate platform in the southern Gulf of Mexico and which has since been buried by Paleogene and Neogene carbonates. Chicxulub is one of few large craters with preserved ejecta deposits, which include the world-wide K/Pg boundary clay layer. The impact has been related to the global major environmental and climatic effects and the organism mass extinction that mark the K/Pg boundary, which affected more than 70 % of organisms, including the dinosaurs, marine and flying reptiles, ammonites and a large part of the marine microorganisms. The impact and crater formation occur instantaneously, with excavation of the crust down to 25 km depths in fractions of second and lower crust uplift and crater formation in a few hundreds of seconds. Energy released by impact and crustal deformation generates seismic waves traveling the whole Earth, and resulting in intense fracturing and deformation at the target site. Understanding of the physics of impacts on planetary surfaces and modeling of processes of crustal deformation, rheological behavior of materials at high temperatures and pressures remain a major challenge in geosciences. Study of the Chicxulub crater and the global effects and mass extinction requires inter- and multidisciplinary approaches, with researchers from many diverse fields beyond the geosciences. With no surface exposures, geophysical surveys and drilling are required to study the crater. Differential compaction between the impact breccias and the surrounding carbonate rocks has produced a ring-fracture structure that at the surface reflects in a small topographic depression and the karstic cenote ring. The crater structure, located half offshore and half on-land, has been imaged by

  1. Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Exploration Geophysics

    ERIC Educational Resources Information Center

    Savit, Carl H.

    1978-01-01

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

  3. Geophysical Surveys of the San Andreas and Crystal Springs Reservoir System Including Seismic-Reflection Profiles and Swath Bathymetry, San Mateo County, California

    USGS Publications Warehouse

    Finlayson, David P.; Triezenberg, Peter J.; Hart, Patrick E.

    2010-01-01

    This report describes geophysical data acquired by the U.S. Geological Survey (USGS) in San Andreas Reservoir and Upper and Lower Crystal Springs Reservoirs, San Mateo County, California, as part of an effort to refine knowledge of the location of traces of the San Andreas Fault within the reservoir system and to provide improved reservoir bathymetry for estimates of reservoir water volume. The surveys were conducted by the Western Coastal and Marine Geology (WCMG) Team of the USGS for the San Francisco Public Utilities Commission (SFPUC). The data were acquired in three separate surveys: (1) in June 2007, personnel from WCMG completed a three-day survey of San Andreas Reservoir, collecting approximately 50 km of high-resolution Chirp subbottom seismic-reflection data; (2) in November 2007, WCMG conducted a swath-bathymetry survey of San Andreas reservoir; and finally (3) in April 2008, WCMG conducted a swath-bathymetry survey of both the upper and lower Crystal Springs Reservoir system. Top of PageFor more information, contact David Finlayson.

  4. High-resolution geophysical data collected along the Delmarva Peninsula 2014, U.S. Geological Survey Field Activity 2014-002-FA

    USGS Publications Warehouse

    Pendleton, Elizabeth; Ackerman, Seth; Baldwin, Wayne E.; Danforth, William W.; Foster, David S.; Thieler, E. Robert; Brothers, Laura

    2016-01-01

    The Delmarva Peninsula is a 220-kilometer-long headland, spit, and barrier island complex that was significantly affected by Hurricane Sandy. A U.S. Geological Survey cruise was conducted in the summer of 2014 to map the inner continental shelf of the Delmarva Peninsula using geophysical and sampling techniques to define the geologic framework that governs coastal system evolution at storm-event and longer timescales. Data collected during the 2014 cruise include swath bathymetry, sidescan sonar, chirp and boomer seismic-reflection profiles, acoustic Doppler current profiler, and sample and bottom photograph data. Processed data in raster and vector format are released for the swath bathymetry, sidescan sonar, and seismic-reflection profiles. More information about the USGS survey conducted as part of the Hurricane Sandy Response-- Geologic Framework and Coastal Vulnerability Study can be found at the project website or on the Woods Hole Coastal and Marine Science Center Field Activity Web pages:

  5. Description of the US Geological Survey`s slug-test and borehole geophysical-logging work at the Hallam Nuclear Facility. July to November 1994

    SciTech Connect

    1994-12-01

    Four aquifer slug-tests were performed in two observation wells 1B and 4C at Hallam Nuclear Facility, Nebraska. Well 1B responded more rapidly than 4C. Borehole geophysics data were collected in observation wells 1B, 4C, B-4, B-8, and B-10 on November 3.

  6. The implementation of multi-task geophysical survey to locate Cleopatra Tomb at Tap-Osiris Magna, Borg El-Arab, Alexandria, Egypt “Phase II”

    NASA Astrophysics Data System (ADS)

    Abbas, Abbas M.; Khalil, Mohamed A.; Massoud, Usama; Santos, Fernando M.; Mesbah, Hany A.; Lethy, Ahmed; Soliman, Mamdouh; Ragab, El Said A.

    2012-06-01

    According to some new discoveries at Tap-Osiris Magna temple (West of Alexandria), there is potentiality to uncover a remarkable archeological finding at this site. Three years ago many significant archeological evidences have been discovered sustaining the idea that the tomb of Cleopatra and Anthony may be found in the Osiris temple inside Tap-Osiris Magna temple at a depth from 20 to 30 m. To confirm this idea, PHASE I was conducted in by joint application of Ground Penetrating Radar “GPR”, Electrical Resistivity Tomography “ERT” and Magnetometry. The results obtained from PHASE I could not confirm the existence of major tombs at this site. However, small possible cavities were strongly indicated which encouraged us to proceed in investigation of this site by using another geophysical approach including Very Low Frequency Electro Magnetic (VLF-EM) technique. VLF-EM data were collected along parallel lines covering the investigated site with a line-to-line spacing of 1 m. The point-to-point distance of 1 m along the same line was employed. The data were qualitatively interpreted by Fraser filtering process and quantitatively by 2-D VLF inversion of tipper data and forward modeling. Results obtained from VLF-EM interpretation are correlated with 2-D resistivity imaging and drilling information. Findings showed a highly resistive zone at a depth extended from about 25-45 m buried beneath Osiris temple, which could be indicated as the tomb of Cleopatra and Anthony. This result is supported by Fraser filtering and forward modeling results. The depth of archeological findings as indicated from the geophysical survey is correlated well with the depth expected by archeologists, as well as, the depth of discovered tombs outside Tap-Osiris Magna temple. This depth level has not been reached by drilling in this site. We hope that the site can be excavated in the future based on these geophysical results.

  7. Use of surface and borehole geophysical surveys to determine fracture orientation and other site characteristics in crystalline bedrock terrain, Millville and Uxbridge, Massachusetts

    USGS Publications Warehouse

    Hansen, Bruce P.; Lane, Jr., John W.

    1995-01-01

    Four geophysical techniques were used to determine bedrock-fracture orientation and other site characteristics that can be used to determine ground-water movement and contaminant transport at a fractured crystalline bedrock site in Millville and Uxbridge, Massachusetts. Azimuthal seismic- refraction and azimuthal square-array direct-current resistivity surveys were conducted at three sites. Borehole-radar surveys were conducted in a cluster of three wells. Ground-penetrating radar surveys were conducted along roads in the study area. Azimuthal seismic-refraction data indicated a primary fracture strike between 56 and 101 degrees at three sites. Graphical and analytical analysis of azimuthal square-array resistivity data indicated a primary fracture strike from 45 to 90 degrees at three sites. Directional borehole-radar data from three wells indicated 46 fractures or fracture zones located as far as 147 feet from the surveyed wells. Patterns of low radar-wave velocity and high radar- wave attenuation from cross-hole radar surveys of two well pairs were interpreted as a planar fracture zone that strikes 297 degrees and dips 55 degrees south. Ground-penetrating radar surveys with 100-MHz antennas penetrated as much as 150 feet of bedrock where the bedrock surface was at or near land surface. Horizontal and subhorizontal fractures were observed on the ground-penetrating radar records at numerous locations. Correlation of data sets indicates good agreement and indicates primary high- angle fracturing striking east-northeast. Secondary bedrock porosity and average fracture aperture determined from square-array resistivity data averaged 0.0044 and 0.0071 foot. Depths to bedrock observed on the ground-penetrating radar records were 0 to 20 feet below land surface along most of the area surveyed. A bedrock depth from 45 to 50 feet below land surface was observed along one section of Conestoga Drive.

  8. Particle Geophysics

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiroyuki K. M.

    2014-05-01

    Geophysics research has long been dominated by classical mechanics, largely disregarding the potential of particle physics to augment existing techniques. The purpose of this article is to review recent progress in probing Earth's interior with muons and neutrinos. Existing results for various volcanological targets are reviewed. Geoneutrinos are also highlighted as examples in which the neutrino probes elucidate the composition of Earth's deep interior. Particle geophysics has the potential to serve as a useful paradigm to transform our understanding of Earth as dramatically as the X-ray transformed our understanding of medicine and the body.

  9. Mapping Ground Water in Three Dimensions - An Analysis of Airborne Geophysical Surveys of the Upper San Pedro River Basin, Cochise County, Southeastern Arizona

    USGS Publications Warehouse

    Wynn, Jeff

    2006-01-01

    This report summarizes the results of two airborne geophysical surveys conducted in the upper San Pedro Valley of southeastern Arizona in 1997 and 1999. The combined surveys cover about 1,000 square kilometers and extend from the Huachuca Mountains on the west to the Mule Mountains and Tombstone Hills on the east and from north of the Babocomari River to near the Mexican border on the south. The surveys included the acquisition of high-resolution magnetic data, which were used to map depth to the crystalline basement rocks underlying the sediments filling the basin. The magnetic inversion results show a complex basement morphology, with sediment thickness in the center of the valley ranging from ~237 meters beneath the city of Sierra Vista to ~1,500 meters beneath Huachuca City and the Palominas area near the Mexican border. The surveys also included acquisition of 60-channel time-domain electromagnetic (EM) data. Extensive quality analyses of these data, including inversion to conductivity vs. depth (conductivity-depth-transform or CDT) profiles and comparisons with electrical well logs, show that the electrical conductor mapped represents the subsurface water-bearing sediments throughout most of the basin. In a few places (notably the mouth of Huachuca Canyon), the reported water table lies above where the electrical conductor places it. These exceptions appear to be due to a combination of outdated water-table information, significant horizontal displacement between the wells and the CDT profiles, and a subtle calibration issue with the CDT algorithm apparent only in areas of highly resistive (very dry) overburden. These occasional disparities appear in less than 5 percent of the surveyed area. Observations show, however, that wells drilled in the thick unsaturated zone along the Huachuca Mountain front eventually intersect water, at which point the water rapidly rises high into the unsaturated zone within the wellbore. This rising of water in a wellbore implies

  10. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  11. Geophysical survey, Paso Robles Geothermal area, California: Part of the Resource Assessment of Low- and Moderate-Temperature Geothermal Resource Areas in California; Part of the Second year Report, 1979-80 of the US Department of Energy-California State-Coupled Program for Reservoir Assessment and Confirmation

    SciTech Connect

    Chapman, Rodger H.; Chase, Gordon W.; Youngs, Les G.

    1980-11-10

    This report presents the details of new geophysical work for the Paso Robles geothermal area, California performed under terms of the second year contract, 1979-80 between the US Department of Energy (DOE) and the California Division of Mines and Geology (CDMG). The report contains two sections. The first section is to provide background for the reader and consists of a reprint from CDMG's first year report (1979-80) to DOE. It describes only the Paso Robles studies performed by CDMG in its first year effort. The second section provides new information developed by CDMG in its 1979-80 studies concerning the geophysical survey of the Paso Robles geothermal area. Included in the first section is some general background information concerning the geology and geothermal occurrences in the Southern Coast Ranges, as well as the more detailed information dealing with the Paso Robles area proper. The second section is concerned only with discussion and interpretation of results for two geophysical methods that have so far been used by CDMG in the area: the ground magnetic and gravity surveys. The CDMG studies of the Paso Robles area are not yet complete and additional studies using newly acquired resistivity equipment are planned for the near future, as are more complete surveys of existing wells and new studies of the geothermal aquifers present in the area. A final report to DOE on the Paso Robles area is planned following completion of those studies.

  12. Geophysical Sounding

    NASA Astrophysics Data System (ADS)

    Blake, E.

    1998-01-01

    Of the many geophysical remote-sensing techniques available today, a few are suitable for the water ice-rich, layered material expected at the north martian ice cap. Radio echo sounding has been used for several decades to determine ice thickness and internal structure. Selection of operating frequency is a tradeoff between signal attenuation (which typically increases with frequency and ice temperature) and resolution (which is proportional to wavelength). Antenna configuration and size will be additional considerations for a mission to Mars. Several configurations for ice-penetrating radar systems are discussed: these include orbiter-borne sounders, sounding antennas trailed by balloons and penetrators, and lander-borne systems. Lander-borne systems could include short-wave systems capable of resolving fine structure and layering in the upper meters beneath the lander. Spread-spectrum and deconvolution techniques can be used to increase the depth capability of a radar system. If soundings over several locations are available (e.g., with balloons, rovers, or panning short-wave systems), then it will be easier to resolve internal layering, variations in basal reflection coefficient (from which material properties may be inferred), and the geometry of nonhorizontal features. Sonic sounding has a long history in oil and gas exploration. It is, however, unlikely that large explosive charges, or even swept-frequency techniques such as Vibroseis, would be suitable for a Polar lander -- these systems are capable of penetrating several kilometers of material at frequencies of 10-200 Hz, but the energy required to generate the sound waves is large and potentially destructive. The use of audio-frequency and ultrasonic sound generated by piezoelectric crystals is discussed as a possible method to explore layering and fine features in the upper meters of the ice cap. Appropriate choice of transducer(s) will permit operation over a range of fixed or modulated frequencies

  13. Understanding the role played by the basement in the eruptive dynamics combining fieldwork and geophysical surveys: the example of El Puig d'Àdri tuff cone

    NASA Astrophysics Data System (ADS)

    Pedrazzi, Dario; Bolós, Xavier; Barde-Cabusson, Stéphanie; Martí, Joan; Geyer, Adelina

    2015-04-01

    El Puig d'Àdri tuff cone is one of the most peculiar edifices of the Garrotxa Volcanic Field (GVF) (0.6-0.01 Ma), which is part of the Catalan Volcanic Zone (NE of the Iberian Peninsula), one of the Quaternary alkaline volcanic provinces associated with the European Cenozoic Rift System.El Puig d'Àdri volcano was emplaced in the northern sector of La Selva Basin, a Neogene tectonic depression bounded by ENE-WSW-and NW-SE-oriented normal fault systems, above Paleocene and Eocene materials (red sandstones, marls and limestones) covered by Neogene alluvial sediments. The area is bounded to the East by the Amer Fault and to the West by the Llorà Fault. These two regional conjugated Neogene normal faults with a transtensional component are responsible in the area for the distribution of volcanism, seismicity and the fluvial network as well. The construction of this volcano involved various stages due to the periodic magma/water interaction that lead to the superposition of three volcanic vents. The main edifice is constituted by a tuff cone 850 m in diameter with a small scoria cone at the western side of the tuff cone and a new scoria cone further SE. Geological and geophysical surveys (performed using Electrical Resistivity Tomography-ERT and Self-Potential-SP), were reliable tools to understand the eruptive dynamics of this volcano and the major role played by the basement. 5 different litostratigraphic units were identified in El Puig d'Àdri volcano where Strombolian and phreatomagmatic episodes alternated giving rise to complex stratigraphic sequences. A first explosive phreatomagmatic event was followed by a Strombolian episode of limited extent. The activity returned to a stronger phreatomagmatic phase, with dilute PDCs and explosion breccias, along with a concentrate PDC running southern for more than 3 km. A final Strombolian phase gave rise to the construction of the main scoria cone, with deposits covering most of the proximal phreatomagmatic products

  14. Building Geophysics Talent and Opportunity in Africa: Experience from the AfricaArray/Wits Geophysics Field School

    NASA Astrophysics Data System (ADS)

    Webb, S. J.; Manzi, M.; Scheiber-Enslin, S. E.; Durrheim, R. J.; Jones, M. Q. W.; Nyblade, A.

    2015-12-01

    There are many challenges faced by geophysics students and academic staff in Africa that make it difficult to develop effective field and research programs. Challenges to conducting field work that have been identified, and that can be tackled are: lack of training on geophysical equipment and lack of exposure to field program design and implementation. To address these challenges, the AfricaArray/Wits Geophysics field school is designed to expose participants to a wide variety of geophysical instruments and the entire workflow of a geophysical project. The AA field school was initially developed for the geophysics students at the University of the Witwatersrand. However, by increasing the number of participants, we are able to make more effective use of a large pool of equipment, while addressing challenging geophysical problems at a remote field site. These additional participants are selected partially based on the likely hood of being able start a field school at their home institution. A good candidate would have access to geophysical equipment, but may not have knowledge of how to use it or how to effectively design surveys. These are frequently junior staff members or graduate students in leadership roles. The three week program introduces participants to the full geophysical field workflow. The first week is spent designing a geophysical survey, including determining the cost. The second week is spent collecting data to address a real geophysical challenge, such as determining overburden thickness, loss of ground features due to dykes in a mine, or finding water. The third week is spent interpreting and integrating the various data sets culminating in a final presentation. Participants are given all lecture material and much of the software is open access; this is done to encourage using the material at the home institution. One innovation has been to use graduate students as instructors, thus building a pool of talent that has developed the logistic and

  15. Geophysics News 1990

    NASA Astrophysics Data System (ADS)

    Cole, Stephen

    The last two years have witnessed many major geophysical events such as the Loma Prieta earthquake, new insights into plate motions, new seismic and mid-ocean ridge observational programs, and new views of a distant planet. AGU's Public Information Committee, chaired by Debra Knopman of the U.S. Geological Survey, was asked by the American Institute of Physics to prepare a series of articles on the major topics in geophysics for publication in Physics News in 1990. Several of those papers did appear in the AIP publication. In the absence of a comparable publication devoted solely to a summary of news in geophysics, AGU is publishing the 20 articles solicited by the Public Information Committee as a booklet, Geophysics News 1990, that is being distributed to the media. The articles are also being published in Eos starting with this issue and continuing for the next several weeks. The topics covered in these articles range from the world's deepest rocks to the powerful blast waves from major solar flares.

  16. Results of geophysical surveys of glacial deposits near a former waste-disposal site, Nashua, New Hampshire

    USGS Publications Warehouse

    Ayotte, Joseph D.; Dorgan, Tracy H.

    1995-01-01

    Geophysical investigations were done near a former waste-disposal site in Nashua, New Hampshire to determine the thickness and infer hydraulic characteristics of the glacial sediments that underlie the area. Approximately 5 miles of ground- penetrating radar (GPR) data were collected in the study area by use of dual-80 Megahertz antennas. Three distinct radar-reflection signatures were evident from the data and are interpreted to represent (1) glacial lake-bottom sediments, (2) coarse sand and gravel and (or) sandy glacial till, and (3) bedrock. The GPR signal penetrated as much as 70 feet of sediment in coarse-grained areas, but penetration depth was generally less than 40 feet in extensive areas of fine-grained deposits. Geologic features were evident in many of the profiles. Glacial-lake-bottom sediments were the most common features identified. Other features include deltas deposited in glacial Lake Nashua and lobate fans of sediment deposited subaqueously at the distal end of deltaic sediments. Cross-bedded sands were often identifiable in the deltaic sediments. Seismic-refraction data were also collected at five of the GPR data sites. In most cases, depths to the water table and to the till and (or) bedrock surface indicated by the seismic-refraction data compared favorably with depths calculated from the GPR data. Test holes were drilled at three locations to determine the true depths to radar reflectors and to determine the types of geologic material represented by the various reflectors.

  17. L- and Corner-arryas for 3D electric resistivity tomography: An alternative for geophysical surveys in urban zones

    NASA Astrophysics Data System (ADS)

    Chavez Segura, R. E.; Tejero-Andrade, A.; Delgado-Solorzano, C.; Cifuentes-Nava, G.; Hernández-Quintero, E.

    2011-12-01

    3D Electric Resitivity Tomography methods carried out on heavily urbanized areas become a difficult task, since buildings, houses or other type of obstacles do not allow parallel ERT arrays to be deployed. Therefore, insufficient information from the subsoil could be obtained. The present paper presents two new techniques, which allow acquiring information beneath a construction by simply surrounding the building or buildings to be studied by a series of ERT profiles. Apparent resistivities are obtained from L-shaped profiles, where alternations between current and potential electrodes along this array are carried out in an automatic way. Four L-arrays and four Corner-arrays are needed to cover the subsurface beneath the studied area. A field test was carried out on a small University of Mexico main Campus garden, where trees and other anthropogenic structures were the so called 'obstacles'. Geophysical work was performed employing parallel arrays (traditional methodology) and compared with this new method presented. Results show that the new method has a poor resolution towards the central portion of the area, mainly from anomalies produced by shallow structures as compared with the traditional grid method. However, the L- and Corner- arrays are more sensitive to anomalies produced by deeper objects, which cannot be observed in the traditional method. The final goal is to apply this method to study habitational complexes built on top of the ancient lake of Mexico City, where buildings are in constant risk due to fracturing and subsidence.

  18. Interpretation of an airborne geophysical survey in southern Paris Basin: towards a lithological cartography, key tool for the management of shrinking/swelling clay problems

    NASA Astrophysics Data System (ADS)

    Prognon, F.; Tourliere, B.; Perrin, J.; Lacquement, F.; Martelet, G.; Deparis, J.; Gourdier, S.; Drufin, S.

    2011-12-01

    Regolith formations support a full spectrum of human activities. Among others, they provide a source of extractable materials and form the substratum of soils. As such, they should be considered as a capital to be managed and protected. Moreover, one of the main challenges for present and future land settlement is to prevent house building programs from being planned inside shrink-swell risky areas which is only possible thanks to an complete lithological mapping of the french regolith. We illustrate here the results of the geological interpretation of an airborne geophysical survey carried out in "Région Centre" administrative region in the southern part of the Paris Basin, in France. Among other techniques, airborne geophysics is appropriate to quickly provide information on near surface, because of i) its high spatial coverage ii) the rapidity of acquisition and iii) the variety of available sensors (magnetic, spectral radiometry, electromagnetic...). Spectral radiometry data were collected with a line spacing of 1 km. This method provides maps of potassium (K), uranium (U) and thorium (Th) which are the only naturally occurring elements with direct or indirect radioisotopes that produce gamma rays of sufficient intensity to be measured at airborne survey heights. On the radiometric data we applied the HAC (Hierarchical Ascendant Classification) computation procedure: taking into account several variables, the statistical HAC method groups individuals based on their resemblance. Also in this study, calibrated Total Count channel (TCm) is compared to an estimated dose rate (TCe) computed from the measured radioelement abundances: TCe = 13.078 * K + 5.675 * U + 2.494 * Th. Our results show that the ratio TCe/TCm came out to be a good indicator of ground property changes within Sologne mixed sandy-clay environment. Processed geophysical data are cross-checked with geological data (from field observations) and field or laboratory measurements of mineralogical data

  19. Subsurface structure of a maar-diatreme and associated tuff ring from a high-resolution geophysical survey, Rattlesnake Crater, Arizona

    NASA Astrophysics Data System (ADS)

    Marshall, Anita; Connor, Charles; Kruse, Sarah; Malservisi, Rocco; Richardson, Jacob; Courtland, Leah; Connor, Laura; Wilson, James; Karegar, Makan A.

    2015-10-01

    Geophysical survey techniques including gravity, magnetics, and ground penetrating radar were utilized to study the diatreme and tuff ring at Rattlesnake Crater, a maar in the San Francisco Volcanic Field of northern Arizona. Significant magnetic anomalies (+ 1600 nT) and a positive gravity anomaly (+ 1.4 mGal) are associated with the maar. Joint modeling of magnetic and gravity data indicate that the diatreme that underlies Rattlesnake Crater has volume of 0.8-1 km3, and extends to at least 800 m depth. The modeled diatreme comprises at least two zones of variable density and magnetization, including a low density, highly magnetized unit near the center of the diatreme, interpreted to be a pyroclastic unit emplaced at sufficiently high temperature and containing sufficient juvenile fraction to acquire thermal remanent magnetization. Magnetic anomalies and ground penetrating radar (GPR) imaging demonstrate that the bedded pyroclastic deposits of the tuff ring also carry high magnetization, likely produced by energetic emplacement of hot pyroclastic density currents. GPR profiles on the tuff ring reveal long (~ 100 m) wavelength undulations in bedding planes. Elsewhere, comparable bedforms have been interpreted as base surge deposits inflated by air entrainment from eruption column collapse. Interpretation of these geophysical data suggests that Rattlesnake Crater produced highly energetic phreatomagmatic activity that gave way to less explosive activity as the eruption progressed. The positive gravity anomaly associated with the maar crater is interpreted to be caused by coherent bodies within the diatreme and possibly lava ponding on the crater floor. These dense magnetized bodies have excess mass of 2-4 × 1010 kg, and occupy approximately 5% of the diatreme by volume. Magnetic anomalies on the crater floor are elongate NW-SE, suggesting that the eruption may have been triggered by the interaction of ascending magma with water in fractures of this orientation

  20. Combined geophysical surveys and coring data to investigate the pattern of the Watukosek fault system around the Lusi eruption site, Indonesia.

    NASA Astrophysics Data System (ADS)

    Husein, Alwi; Mazzini, Adriano; Lupi, Matteo; Mauri, Guillaume; Kemna, Andreas; Hadi, Soffian; Santosa, Bagus

    2016-04-01

    The Lusi mud eruption is located in the Sidoarjo area, Indonesia and is continuously erupting hot mud since its birth in May 2006. The Watukosek fault system originates from the neighboring Arjuno-Welirang volcanic complex extending towards the NE of Java. After the 27-06-2006 M 6.3 earthquake this fault system was reactivated and hosted numerous hot mud eruptions in the Sidoarjo area. Until now, no targeted investigations have been conducted to understand the geometry of the faults system crossing the Lusi eruption site. A comprehensive combined electrical resistivity and self-potential (SP) survey was performed in the 7 km2 area inside the Lusi embankment that had been built to contain the erupted mud and to prevent flooding of the surrounding roads and settlements. The goal of the geophysical survey is to map the near-surface occurrence of the Watukosek fault system upon which Lusi resides, delineate its spatial pattern, and monitor its development. We completed six lines of resistivity measurements using Wenner configuration and SP measurements using roll-along technique. Three subparallel lines were located to the north and to the south of the main crater. Each line was approximately W-E oriented extending for ~1.26 km. The surveyed regions consist of mud breccia (containing clayey-silty-sandy mixture with clast up to ~10 cm in size). The geophysical data have been complemented with a N-S oriented profile consisting of 6 cores (~30m long) drilled in the dry area inside the Lusi embankment. The resistivity data were inverted into 2-D resistivity images with a maximum penetration depth of almost 200 m. These images consistently reveal a region of about 300 m in width (between 30-90 m depth) characterized by anomalous resistivities, which are lower than the values observed in the surrounding area. The results of the SP data correspond well with the resistivity profiles in the anomalous parts, which suggests that their origin is related to fluid flow paths in the

  1. Design of Reconnaissance Helicopter Electromagnetic and Magnetic Geophysical Surveys of the North Platte River and Lodgepole Creek, Nebraska

    NASA Astrophysics Data System (ADS)

    Smith, B. D.; Cannia, J. C.; Abraham, J. D.

    2009-12-01

    An innovative flight line layout using widely separated lines was used for frequency domain helicopter electromagnetic (HEM) surveys in 2008 and 2009 in the Panhandle of western Nebraska. The HEM survey design was developed as part of a joint hydrologic study by the North Platte Natural Resource District, South Platte Natural Resource District, UNL-Conservation and Survey Division, and U.S. Geological Survey to improve the understanding of relationships between surface water and groundwater systems critical to developing groundwater flow models used in water resources management programs. Use of HEM methods for hydrologic mapping had been demonstrated by HEM surveys conducted in 2007 of sites in the glaciated Platte River Basin in eastern Nebraska. These surveys covered township-scale areas with flight lines laid out in blocks where the lines were spaced about 270m apart. The HEM successfully mapped the complex 3D geometry of shallow sand and gravel aquifers through and within conductive till to a depth of about 40m in a total area of about 680 km2 (263 mi2). Current groundwater flow models in western Nebraska include the Cooperative Hydrologic Study (COHYST), run by a consortium of state agencies, which is tasked to develop scientifically supportable hydrologic databases, analyses, and models, and the North Platte River Valley Optimization Model (NPRVOM). The COHYST study area, about 75,000 km2 (29,000 mi2), includes the Platte River Basin from the Nebraska - Wyoming border to Lincoln. Considering the large area of the groundwater models, the USGS decided in collaboration with the NRD to use a more reconnaissance-style layout for the 2008 HEM survey which encompassed about 21,000 km2 (8,000 mi2). A reconnaissance-type HEM survey is made possible due to technical capabilities of applicable HEM systems and due to the level of hydrogeologic information available in the NRD. The particular capabilities of the HEM system are careful calibration, low drift, low noise

  2. Mitigating the consequences of future earthquakes in historical centres: what perspectives from the joined use of past information and geological-geophysical surveys?

    NASA Astrophysics Data System (ADS)

    Terenzio Gizzi, Fabrizio; Moscatelli, Massimiliano; Potenza, Maria Rosaria; Zotta, Cinzia; Simionato, Maurizio; Pileggi, Domenico; Castenetto, Sergio

    2015-04-01

    To mitigate the damage effects of earthquakes in urban areas and particularly in historical centres prone to high seismic hazard is an important task to be pursued. As a matter of fact, seismic history throughout the world informs us that earthquakes have caused deep changes in the ancient urban conglomerations due to their high building vulnerability. Furthermore, some quarters can be exposed to an increase of seismic actions if compared with adjacent areas due to the geological and/or topographical features of the site on which the historical centres lie. Usually, the strategies aimed to estimate the local seismic hazard make only use of the geological-geophysical surveys. Thorough this approach we do not draw any lesson from what happened as a consequences of past earthquakes. With this in mind, we present the results of a joined use of historical data and traditional geological-geophysical approach to analyse the effects of possible future earthquakes in historical centres. The research activity discussed here is arranged into a joint collaboration between the Department of Civil Protection of the Presidency of Council of Ministers, the Institute of Environmental Geology and Geoengineering and the Institute of Archaeological and Monumental Heritage of the National (Italian) Research Council. In order to show the results, we discuss the preliminary achievements of the integrated study carried out on two historical towns located in Southern Apennines, a portion of the Italian peninsula exposed to high seismic hazard. Taking advantage from these two test sites, we also discuss some methodological implications that could be taken as a reference in the seismic microzonation studies.

  3. Preliminary results of the Deep Freeze 85 marine geologic and geophysical survey of the Antarctic Peninsula continental shelf and South Orkney Plateau

    SciTech Connect

    Anderson, J.B.; Bartek, L.; Griffith, T.; Herron, M.; Kennedy, D.; Singer, J.; Smith, M.

    1985-01-01

    Seismic profiles from the South Orkney Plateau show a relatively thick (>0.7 seconds), laminated sequence resting on block faulted acoustic basement and deformed strata. This represents the rifting of the plateau from the Antarctic Peninsula and subsequent pelagic sedimentation. A glacial erosional surface and associated glacial trough were identified on the platform, and possible basal till collected in at least one piston core. Seismic lines from the continental shelf north of the South Shetland Plateau show gently folded reflectors that have been truncated by a widespread erosional unconformity and probable moraines situated near the shelf edge. A line across the Bransfield Strait, a modern back-arc basin, shows the structural features of the basin and thick (>1.0 second) laminated sediments within the center of the basin. One of several deep channels which dissect the shelf was surveyed, but the origin of these features remains uncertain. Geophysical data and piston cores were acquired in several of the bays and fjords of the peninsula region. This is the first detailed survey of Antarctic bays and fjords. The preliminary results show striking differences in sedimentation between Antarctic fjords and those of Arctic and Subarctic regions, the most important difference being the limited role of meltwater runoff in the supply of sediment to Antarctic fjords.

  4. Heterogeneity of groundwater storage properties in the critical zone of Irish metamorphic basement from geophysical surveys and petrographic analyses

    NASA Astrophysics Data System (ADS)

    Comte, Jean-Christophe; Cassidy, Rachel; Caulfield, John; Nitsche, Janka; Ofterdinger, Ulrich; Wilson, Christopher

    2016-04-01

    Weathered/fractured bedrock aquifers contain groundwater resources that are crucial in hard rock basement regions for rural water supply and maintaining river flow and ecosystem resilience. Groundwater storage in metamorphic rocks is subject to high spatial variations due to the large degree of heterogeneity in fracture occurrence and weathering patterns. Point measurements such as borehole testing are, in most cases, insufficient to characterise and quantify those storage variations because borehole sampling density is usually much lower than the scale of heterogeneities. A suite of geophysical and petrographic investigations was implemented in the weathered/fractured micaschist basement of Donegal, NW Ireland. Electrical Resistivity Tomography provided a high resolution 2D distribution of subsurface resistivities. Resistivity variations were transferred into storage properties (i.e. porosities) in the saturated critical zone of the aquifer through application of a petrophysical model derived from Archie's Law. The petrophysical model was calibrated using complementary borehole gamma logging and clay petrographic analysis at multi-depth well clusters distributed along a hillslope transect at the site. The resulting distribution of porosities shows large spatial variations along the studied transect. With depth, porosities rapidly decrease from about a few % in the uppermost, highly weathered basement to less than 0.5% in the deep unweathered basement, which is encountered at depths of between 10 and 50m below the ground surface. Along the hillslope, porosities decrease with distance from the river in the valley floor, ranging between 5% at the river to less than 1% at the top of the hill. Local traces of regional fault zones that intersect the transect are responsible for local increases in porosity in relation to deeper fracturing and weathering. Such degrees of spatial variation in porosity are expected to have a major impact on the modality of the response of

  5. 78 FR 57354 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-18

    ... determinations and proposing to issue an IHA. The notice initiated a 30-day public comment period. Acoustic... October 2013. Some minor deviation from these dates would be possible, depending on logistics and weather... airguns are towed along the survey lines, the hydrophone streamer will receive the returning...

  6. 78 FR 33811 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... of the Western Pacific Warm Pool to better assess controls on the hydrologic cycle in the Western... (Philippines) (see Figure 1 of the IHA application). Water depths in the survey area range from 450 to 3,000... cycle in the Western Pacific Warm Pool, and a limited meridional coverage to test hypotheses related...

  7. Helicopter-borne geophysical survey over the areas struck by the tsunami of March 11, 2011, in northeast Japan

    NASA Astrophysics Data System (ADS)

    Okuma, S.; Ueda, T.; Mitsuhata, Y.; Uchida, T.

    2012-12-01

    The Geological Survey of Japan, AIST conducted a helicopter-borne EM and magnetic survey over tsunami invaded areas in northeast Japan 15 months after the 2011 off the Pacific coast of Tohoku Earthquake. The purpose of the survey is to map the electrical resistivity of the ground intruded by seawater during the tsunami on March 11, 2011 for its reutilization as farming lands and water assessment of the area. The survey was flown in June 2012 at an altitude of 60m above ground with a speed of 50km/h along survey and traverse lines spaced 100m and 1,000m apart, respectively. The airborne EM system (Fuguro Airborne Surveys' RESOLVE system) was installed in a bird and towed 30m below the helicopter. This is a frequency-domain system operated at five frequencies (340, 1,500, 6,900, 31,000, 140,000 Hz) in a horizontal coplanar configuration and at a frequency (3,300 Hz) in a coaxial configuration. The survey area is located at the border of Miyagi and Fukushima Prefectures along the Pacific coast in the southern part of the Sendai Plain and is divided into two sub-areas: Watari-Yamamoto-Shinchi area (area A) and Matsukawa-ura Bay area (area B). The area A is known for its production of high-quality strawberries on beach ridges and much fresh groundwater has been used for irrigation of strawberries and warming of strawberry greenhouses by water curtain. However, the salinity of groundwater from shallow irrigation wells in this area increased dramatically after the tsunami (Mori et al., 2012). Since it still remains at high level, there is an urgent need to find new water resources. Whereas, the area B is characterized by a beautiful lagoon called the Matsukawa-ura which is preserved as one of prefectural parks of Fukushima Prefecture. Rice fields occupy the areas west of the Matsukawa-ura and most of them were covered by seawater during the attack of the tsunami. Desalinization of the rice fields is being conducted intensively to resume rice farming in these fields. The

  8. Geophysical surveys combined with laboratory soil column experiments to identify and explore risk areas for soil and water pollution in feedlots

    NASA Astrophysics Data System (ADS)

    Espejo-Pérez, Antonio Jesus; Sainato, Claudia Mabel; Jairo Márquez-Molina, John; Giráldez, Juan Vicente; Vanderlinden, Karl

    2014-05-01

    Changes of land use without a correct planning may produce its deterioration with their social, economical and environmental irreversible consequences over short to medium time range. In Argentina, the expansion of soybean fields induced a reduction of the area of pastures dedicated to stockbreeding. As cattle activity is being progressively concentrated on small pens, at feedlots farms, problems of soil and water pollution, mainly by nitrate, have been detected. The characterization of the spatial and temporal variability of soil water content is very important because the mostly advective transport of solutes. To avoid intensive soil samplings, very expensive, one has to recur to geophysical exploration methods. The objective of this work was to identify risk areas within a feedlot of the NW zone of Buenos Aires Province, in Argentina through geophysical methods. The surveys were carried out with an electromagnetic induction profiler EMI-400 (GSSI) and a Time domain Reflectometry (TDR) survey of depth 0-0.10 m with soil sampling and measurement of moisture content with gravimetric method (0-1.0 m). Several trenches were dug inside the pens and also at a test site, where texture, apparent density, saturated hydraulic conductivity (Ks), electrical conductivity of the saturation paste extract and organic matter content (OM) were measured. The water retention curves for these soils were also determined. At one of the pens undisturbed soil columns were extracted at 3 locations. Laboratory analysis for 0-1.0 m indicated that soil texture was classified as sandy loam, average organic matter content (OM) was greater than 2.3% with low values of apparent density in the first 10 cm. The range of spatial dependence of data suggested that the number of soil samples could be reduced. Soil apparent electrical conductivity (ECa) and soil moisture were well correlated and indicated a clear spatial pattern in the corrals. TDR performance was acceptable to identify the spatial

  9. MX Siting Investigation. Mineral Resources Survey, Seven Additional Valleys, Nevada/Utah Siting Area. Volume IV.

    DTIC Science & Technology

    1981-06-23

    8217 AD-AI13 146 ERTEC WESTERN INC. LONG BEACH CA F/6 B/7 MX SITING INVESTIGATION. MINERAL RESOURCES SURVEY, SEVEN AGOITI--ETC(U) UNCLASSIFIED E-TR...50 MINERAL RESOURCES SURVEY SEVEN ADDITIONAL VALLEYS NEVADA/UTAH SITING AREA VOLUME IV 4Prepared for: U. S. Department of the Air Force Ballistic...VALLEY MINERAL RESOURCES SURVEfV STUDY AREA OXJNOARY SEPT. 26, 1960 I MX SITING INVESTIGATION 27 FEDC t97 DEPARTMENT OF THE AIR FORCE I ik 320’- 36 37 4

  10. Shipboard surveys track magnetic sources in marine sediments--geophysical studies of the Stono and North Edisto Inlets near Charleston, South Carolina

    USGS Publications Warehouse

    Shah, Anjana K.; Harris, M. Scott

    2012-01-01

    Magnetic field data are traditionally used to analyze igneous and metamorphic rocks, but recent efforts have shown that magnetic sources within sediments may be detectable, suggesting new applications for high-resolution magnetic field surveys. Candidates for sedimentary sources include heavy mineral sand concentrations rich in magnetite or hematite, alteration-induced glauconite, or biogenic magnetite. Magnetic field surveys can be used to map the distributions of such sources with much denser and more widespread coverage than possible by sampling. These data can then provide constraints on the composition history of local sediments. Mapping such sediments requires the sensor to be relatively close to the source, and filtering approaches may be needed to distinguish signals from both system noise and deeper basement features. Marine geophysical surveys conducted in July, 2010, over the Stono and North Edisto River inlets and their riverine inputs south of Charleston, South Carolina, showed 10- to 40-m-wide, 1- to 6-nT magnetic anomalies associated with shallow, sand-covered seabed. These anomalies are distinct from system noise but are too narrow to represent basement features. The anomalies are present mostly in shallow areas where river sediments originating from upland areas enter the inlets. Surface grab samples from the North Edisto River contain trace amounts of heavy mineral sediments including hematite, maghemite, ilmenite, and magnetite, as well as garnet, epidote, zircon, and rutile. Previous stream sediment analyses show enhanced titanium over much of the Atlantic Coastal Plain. The combined data suggest that the anomalies are generated by titanium- and iron-rich heavy mineral sands ultimately originating from the Piedmont and Blue Ridge provinces, which are then reworked and concentrated by tidal currents.

  11. Environmental Assessment for a Marine Geophysical Survey of Parts of the Arctic Ocean, August-September 2010

    USGS Publications Warehouse

    Haley, Beth; Ireland, Darren; Childs, Jonathan R.

    2010-01-01

    /details-eng.cfm?pid=38185 (2008) and http://www.ceaa.gc.ca/052/details-eng.cfm?pid=46518 (2009). The U.S. Geological Survey (USGS) and Geological Survey of Canada (GSC) are undertaking a similar partnership again for 2010 in a limited area of U.S. waters during the period between ~10 and 16 August. The survey vessels will then proceed to international or Canadian waters where surveying will proceed until ~3 September, when the two icebreakers will separate to conduct independent work. The survey area of the joint work will be bounded approximately by 145? to 158? W longitude and 71? to 84? N latitude in water depths ranging from ~2,000 to 4,000 m (fig. 1). Ice conditions are expected to range from open water to 10/10 ice cover. The Louis S. St. Laurent will join accompanying vessel Healy in or near the survey area around 10 August to begin the joint survey work. As its energy source, the seismic system aboard Louis S. St. Laurent will employ a 3-airgun array consisting of three Sercel G-airguns. Two guns will have a discharge volume of 500 in3 and the third a discharge volume of 150 in3 for a total array discharge volume of 1,150 in3. The seismic survey will take place in water depths 2,000?4,000 m. This airgun array is identical to the system used in the 2008 and 2009 field programs by the Geological Survey of Canada. The USGS requested that the National Marine Fisheries Service (NMFS) issue an Incidental Harassment Authorization (IHA) to authorize the incidental, that is, not intentional, harassment of small numbers of cetaceans and seals should this occur during the seismic survey in U.S. waters. USGS is also consulting with the U.S. Fish and Wildlife Service (USFWS) regarding concerns about disturbance to walruses and polar bears. Through informal consultation with the Office of Protected Resources with the National Oceanic and Atmospheric Administration (NOAA), USGS proposes that no ESA-listed marine species?bowhead, fin, humpback or sperm whale?w

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  13. Identification of water-bearing zones by the use of geophysical logs and borehole television surveys, collected February to September 1997, at the Former Naval Air Warfare Center, Warminster, Bucks County, Pennsylvania

    USGS Publications Warehouse

    Conger, Randall W.

    1998-01-01

    Between February 1997 and September 1997, 10 monitor wells were drilled near the site of the former Naval Air Warfare Center, Warminster, Bucks County, Pa., to monitor water levels and sample ground-water contaminants in the shallow, intermediate, and deep water-bearing zones. The sampling will determine the horizontal and vertical distribution of contaminated ground water migrating from known or suspected contaminant sources. Four wells were drilled north of the property adjacent to Area A, three wells along strike located on Lewis Drive, and three wells directly down dip on Ivyland Road. Well depths range from 69 feet to 300 feet below land surface. Borehole-geophysical logging and television surveys were used to identify water-bearing zones so that appropriate intervals could be screened in each monitor well. Geophysical logs were obtained at the 10 monitor wells. Borehole television surveys were obtained at the four monitor wells adjacent to Area A. Caliper and borehole television surveys were used to locate fractures, inflections on fluidtemperature and fluid-resistivity logs were used to locate possible water-bearing fractures, and heatpulse- flowmeter measurements verified these locations. Natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, borehole television surveys, and driller?s logs, all wells were screened such that water-level fluctuations could be monitored and water samples collected from discrete water-bearing zones in each borehole.

  14. Airborne geophysical surveys in the north-central region of Goias (Brazil): implications for radiometric characterization of tropical soils.

    PubMed

    Guimaraes, Suze Nei P; Hamza, Valiya M; da Silva, Joney Justo

    2013-02-01

    Progress obtained in analysis aerogammaspectrometric and aeromagnetic survey data for the north-central region of the state of Goias (Brazil) are presented. The results obtained have allowed not only determination of the abundances of naturally radioactive elements but also new insights into the processes that determine the radiometric characteristics of the main soil types. There are indications that the radioelement abundances of soils are not only related to their physical properties, but also chemical characteristics of source rocks from which they are derived. For example, oxisol soils derived from the felsic source rocks of the Mara Rosa and Green stone belts have equivalent uranium (eU) values higher than 1.7 ppm, while those derived from source rocks of the relatively more basic Uruaçu Group and sediment sequences of Proterozoic age are characterized by eU contents of less than 1 ppm. Oxisol soils of the Median massif, ultisol soils of the Paranoá, Canastra and Araxá Groups, cambisol soils of the Araí Group and plintosol soils of the Bambuí Group constitute an intermediate class with eU contents in the range of 1-1.3 ppm. Equivalent thorium abundances of soil types display similar trends, the range of variation being 4-16 ppm. Potassium abundances on the other hand are rather uniform with values in the range of 1-1.3%, the only exception being the sedimentary sequences of Proterozoic age, which has a mean value of 0.7%. These observations have been considered as indicative of characteristic features of tropical soils in the study area. In this context, we point out the possibility of using results of aerogammaspectrometry surveys as a convenient complementary tool in identifying geochemical zoning of soils in tropical environments. The ratios of eU/K are found to fall in the range of 1-1.7, which is typical of common soils. The ratios of eTh/K exhibit a relatively wide interval, with values in the range of 4-16. The ratios of eTh/eU are found to have

  15. Evaluation of airborne geophysical surveys for large-scale mapping of contaminated mine pools: draft final report

    SciTech Connect

    Hammack, R. W.

    2006-12-28

    Decades of underground coal mining has left about 5,000 square miles of abandoned mine workings that are rapidly filling with water. The water quality of mine pools is often poor; environmental regulatory agencies are concerned because water from mine pools could contaminate diminishing surface and groundwater supplies. Mine pools are also a threat to the safety of current mining operations. Conversely, mine pools are a large, untapped water resource that, with treatment, could be used for a variety of industrial purposes. Others have proposed using mine pools in conjunction with heat pumps as a source of heating and cooling for large industrial facilities. The management or use of mine pool water requires accurate maps of mine pools. West Virginia University has predicted the likely location and volume of mine pools in the Pittsburgh Coalbed using existing mine maps, structure contour maps, and measured mine pool elevations. Unfortunately, mine maps only reflect conditions at the time of mining, are not available for all mines, and do not always denote the maximum extent of mining. Since 1999, the National Energy Technology Laboratory (NETL) has been evaluating helicopter-borne, electromagnetic sensing technologies for the detection and mapping of mine pools. Frequency domain electromagnetic sensors are able to detect shallow mine pools (depth < 50 m) if there is sufficient contrast between the conductance of the mine pool and the conductance of the overburden. The mine pools (conductors) most confidently detected by this technology are overlain by thick, resistive sandstone layers. In 2003, a helicopter time domain electromagnetic sensor was applied to mined areas in southwestern Virginia in an attempt to increase the depth of mine pool detection. This study failed because the mine pool targets were thin and not very conductive. Also, large areas of the surveys were degraded or made unusable by excessive amounts of cultural electromagnetic noise that obscured the

  16. Geophysics publications honored

    NASA Astrophysics Data System (ADS)

    Geophysics and geology publications by the U.S. Geological Survey were awarded one first- and two third-place prizes at the ‘Blue Pencil’ ceremony last month, sponsored by the National Association of Government Communicators.First place in the news release category went to Frank Forrester, an AGU member and recently retired USGS information officer. Editors and artists of the bimonthly USGS Earthquake Information Bulletin were awarded third place in the category for technical magazines using at least two colors.

  17. Expedited Site Characterization geophysics: Geophysical methods and tools for site characterization

    SciTech Connect

    Goldstein, N.E.

    1994-03-01

    This report covers five classes of geophysical technologies: Magnetics; Electrical/electromagnetic; Seismic reflection; Gamma-ray spectrometry; and Metal-specific spectrometry. Except for radiometry, no other classes of geophysical tedmologies are specific for direct detection of the types of contaminants present at the selected sites. For each of the five classes covered, the report gives a general description of the methodology, its field use, and its general applicability to the ESC Project. In addition, the report gives a sample of the most promising instruments available for each class, including the following information: Hardware/software attributes; Purchase and rental costs; Survey rate and operating costs; and Other applicable information based on case history and field evaluations.

  18. An experimental survey of additives for improving dehydrogenation properties of magnesium hydride

    NASA Astrophysics Data System (ADS)

    Zhou, Chengshang; Fang, Zhigang Zak; Sun, Pei

    2015-03-01

    The use of a wide range of additives has been known as an important method for improving hydrogen storage properties of MgH2. There is a lack of a standard methodology, however, that can be used to select or compare the effectiveness of different additives. A systematic experimental survey was carried out in this study to compare a wide range of additives including transitions metals, transition metal oxides, hydrides, intermetallic compounds, and carbon materials, with respect to their effects on dehydrogenation properties of MgH2. MgH2 with various additives were prepared by using a high-energy-high-pressure planetary ball milling method and characterized by using thermogravimetric analysis (TGA) techniques. The results showed that additives such as Ti and V-based metals, hydride, and certain intermetallic compounds have strong catalytic effects. Additives such as Al, In, Sn, Si showed minor effects on the kinetics of the dehydrogenation of MgH2, while exhibiting moderate thermodynamic destabilizing effects. In combination, MgH2 with both kinetic and thermodynamic additives, such as the MgH2-In-TiMn2 system, exhibited a drastically decreased dehydrogenation temperature.

  19. TOMO-ETNA MED-SUV.ISES an active seismic and passive seismic experiment at Mt. Etna volcano. An integrated marine and onland geophysical survey.

    NASA Astrophysics Data System (ADS)

    Ibáñez, Jesus. M.; Patane, Domenico; Puglisi, Guisseppe; Zuccarello, Lucciano; Bianco, Francesca; Luehr, Birger; Diaz-Moreno, Alejandro; Prudencio, Janire; Koulakov, Ivan; Del Pezzo, Edoardo; Cocina, Ornella; Coltelli, Mauro; Scarfi, Lucciano; De Gori, Pascuale; Carrion, Francisco

    2014-05-01

    An active seismic experiment to study the internal structure of Etna Volcano is going to carried out on Sicily and Aeolian islands. The main objective of the TOMO-ETNA MED-SUV.ISES experiment, beginning in summer 2014, is to perform a high resolution seismic tomography, in velocity and attenuation, in Southern Italy, by using active and passive seismic data, in an area encompassing outstanding volcanoes as Mt. Etna, and Aeolian volcanoes. The achievement of this objective is based on the integration and sharing of the in-situ marine and land experiments and observations and on the implementation of new instruments and monitoring systems. For the purpose, onshore and offshore seismic stations and passive and active seismic data generated both in marine and terrestrial environment will be used. Additionally, other geophysical data, mainly magnetic and gravimetric data will be considered to obtain a joint Upper Mantle-Crust structure that could permit to make progress in the understanding of the dynamic of the region. This multinational experiment which involves institutions from Spain, Italy, Germany, United Kingdom, Ireland, France, Malta, Portugal, Russia, USA and Mexico. During the experiment more than 6.600 air gun shots performed by the Spanish Oceanographic vessel "Sarmiento de Gamboa" will be recorder on a dense local seismic network consisting of 100 on land non-permanent stations, 70 on land permanent stations and 20-25 OBSs. Contemporaneously other marine geophysical measures will be performed using a marine Gravimeter LaCoste&Romberg Air-Sea Gravity System II and a Marine Magnetometer SeaSPY. The experiments will provide a unique data set in terms of data quantity and quality, and it will provide a detailed velocity and attenuation structural image of volcano edifice. The results will be essential in the development and interpretation of future volcanic models. It is noteworthy that this project is fully transversal, multidisciplinary and crosses several

  20. Use of Seismic and Magnetic Surveys in a Regional Geophysical Study for Geothermal Exploration in NE Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Poureslami Ardakani, E.; Schmitt, D. R.; Moeck, I.

    2012-12-01

    NE Alberta hosts many producing oil sand projects. These projects require large amounts of thermal energy to produce most of which is currently provided by burning natural gas; and this increases the greenhouse gas footprint to producing such hydrocarbons. One possible solution is to instead use geothermal heat directly with hot fluids produced using Engineered Geothermal Systems (EGS). Geothermal exploration always starts with broad geological structure reconnaissance of the area. Unfortunately, the larger geological context particularly beneath those relatively shallow depths (typically less than 400 m) of interest to hydrocarbon exploration, is still poorly understood. As such, we have selected a rectangular area of 22000 km2 extending across 56.25 to 57.12N and 111.92 to 113.52W that we refer to as the Athabasca region. . The main two categories of data which are in used consist of over 600 km seismic reflection profiles and 22,000 km2 high resolution aeromagnetic (HRAM) data. Also there is a large amount of available well-logs from 1,000 boreholes in this area that have a key role in interpretation of seismic profiles. These integrated data sets are used for outlining sedimentary basin, mapping geological formation tops, locating fault zones and other structural lineaments, finding true depth of metamorphic basement and Curie point, and finally building a geological model of the region. To date all the formation tops are mapped through the area and picked on the seismic profiles. HRAM data is gridded using minimum curvature method. Some structural lineaments are picked on the HRAM data including a great NE-SW fault zone which is in agreement with seismic and well-logs. Additionally, the region hosts interesting geological features such as channels, pinnacle reefs and unconformities that are distinguishable on seismic profiles. Any of these findings help us to get a better view of the region for geothermal exploration.

  1. Fluid mechanics of additive manufacturing of metal objects by accretion of droplets - a survey

    NASA Astrophysics Data System (ADS)

    Tesař, Václav

    2016-03-01

    Paper presents a survey of principles of additive manufacturing of metal objects by accretion of molten metal droplets, focusing on fluid-mechanical problems that deserve being investigated. The main problem is slowness of manufacturing due to necessarily small size of added droplets. Increase of droplet repetition rate calls for basic research of the phenomena that take place inside and around the droplets: ballistics of their flight, internal flowfield with heat and mass transfer, oscillation of surfaces, and the ways to elimination of satellite droplets.

  2. Additional Ultracool White Dwarfs Found In The Sloan Digital Sky Survey

    DTIC Science & Technology

    2008-05-20

    the Sloan Digital Sky Survey ( SDSS ). The SDSS pho- tometry, spectra, and proper motions are presented, and additional BVRI data are given for these and...models for very cool white dwarfs. One of the new stars ( SDSS J1251+44) exhibits strong collision- induced absorption (CIA) in its spectra, while the...spectra and colors of the other six are consistent with mild CIA. Another of the new discoveries ( SDSS J2239+00A) is part of a binary system—its

  3. A brief survey of sensing for metal-based powder bed fusion additive manufacturing

    NASA Astrophysics Data System (ADS)

    Foster, Bryant K.; Reutzel, Edward W.; Nassar, Abdalla R.; Dickman, Corey J.; Hall, Benjamin T.

    2015-05-01

    Purpose - Powder bed fusion additive manufacturing (PBFAM) of metal components has attracted much attention, but the inability to quickly and easily ensure quality has limited its industrial use. Since the technology is currently being investigated for critical engineered components and is largely considered unsuitable for high volume production, traditional statistical quality control methods cannot be readily applied. An alternative strategy for quality control is to monitor the build in real time with a variety of sensing methods and, when possible, to correct any defects as they occur. This article reviews the cause of common defects in powder bed additive manufacturing, briefly surveys process monitoring strategies in the literature, and summarizes recently-developed strategies to monitor part quality during the build process. Design/methodology/approach - Factors that affect part quality in powder bed additive manufacturing are categorized as those influenced by machine variables and those affected by other build attributes. Within each category, multiple process monitoring methods are presented. Findings - A multitude of factors contribute to the overall quality of a part built using PBFAM. Rather than limiting processing to a pre-defined build recipe and assuming complete repeatability, part quality will be ensured by monitoring the process as it occurs and, when possible, altering the process conditions or build plan in real-time. Recent work shows promise in this area and brings us closer to the goal of wide-spread adoption of additive manufacturing technology. Originality/value - This work serves to introduce and define the possible sources of defects and errors in metal-based PBFAM, and surveys sensing and control methods which have recently been investigated to increase overall part quality. Emphasis has been placed on novel developments in the field and their contribution to the understanding of the additive manufacturing process.

  4. The Galactic O-Star Spectroscopic Survey (GOSSS). III. 142 Additional O-type Systems.

    NASA Astrophysics Data System (ADS)

    Maíz Apellániz, J.; Sota, A.; Arias, J. I.; Barbá, R. H.; Walborn, N. R.; Simón-Díaz, S.; Negueruela, I.; Marco, A.; Leão, J. R. S.; Herrero, A.; Gamen, R. C.; Alfaro, E. J.

    2016-05-01

    This is the third installment of the Galactic O-Star Spectroscopic Survey (GOSSS), a massive spectroscopic survey of Galactic O stars, based on new homogeneous, high signal-to-noise ratio, R ˜ 2500 digital observations selected from the Galactic O-Star Catalog. In this paper, we present 142 additional stellar systems with O stars from both hemispheres, bringing the total of O-type systems published within the project to 590. Among the new objects, there are 20 new O stars. We also identify 11 new double-lined spectroscopic binaries, 6 of which are of O+O type and 5 of O+B type, and an additional new tripled-lined spectroscopic binary of O+O+B type. We also revise some of the previous GOSSS classifications, present some egregious examples of stars erroneously classified as O-type in the past, introduce the use of luminosity class IV at spectral types O4-O5.5, and adapt the classification scheme to the work of Arias et al. The GOSSS spectroscopic data in this article were gathered with five facilities: the 1.5 m Telescope at the Observatorio de Sierra Nevada (OSN), the 2.5 m du Pont Telescope at Las Campanas Observatory (LCO), the 3.5 m Telescope at Calar Alto Observatory (CAHA), and the 4.2 m William Herschel Telescope (WHT) and 10.4 m Gran Telescopio Canarias (GTC) at Observatorio del Roque de los Muchachos (ORM).

  5. Airborne geophysical surveys used to delineate geological features associated with the M5.8 August 23, 2011 earthquake in Louisa County, Virginia

    NASA Astrophysics Data System (ADS)

    Shah, A. K.; Horton, J. W.; Gilmer, A. K.

    2012-12-01

    The M5.8 August 23, 2011 Louisa County, VA intraplate earthquake was felt by more people than any other in U.S. history not only because of population density, but also because of the associated geology. However, because limited bedrock exposures pose a challenge to geologic mapping efforts and the earthquake hypocenter is located at a depth of ~6 km, many questions remain. Potential field and gamma-ray spectrometry data thus provide key tools for imaging and understanding both shallow and deep subsurface geologic features. In July 2012, the USGS commissioned a high-resolution magnetic, gravity, and radiometric (gamma-ray spectrometry) survey over a 20 km x 25 km area covering the epicenters of the Louisa County earthquake and its aftershocks. The surveys were flown with 200-m line spacing from an altitude of ~120 m above ground, providing up to a 20-fold improvement over regional magnetic and radiometric coverage. Gravity was measured using Sander Geophysics' AIRGrav system, capable of resolving anomalies as narrow as 800 m for the given survey configuration; in most parts of the survey area the spacing of ground stations is ~10-20 stations per 100 km2. Preliminary magnetic and radiometric data show numerous NE-trending linear anomalies within this part of the Appalachian Piedmont Province. These metamorphic and igneous rocks exhibit 200-500 nT magnetic anomalies of width 300-1000 km that are likely to be generated by contrasts between various metavolcanic and metasedimentary rocks such as magnetite-bearing quartzites and felsic to mafic gneisses. Magnetic lows and radiometric highs are observed over several granitoid intrusive bodies such as the Ellisville pluton, the Falmouth Intrusive Suite, and a Paleozoic pegmatite belt. Derivative magnetic maps delineate numerous thin (< 250 m wide) N- NNW-trending linear anomalies, suggesting that Jurassic diabase dikes are much more common in this area than previously mapped. Radiometric data mostly correlate with mapped

  6. Water Detection Response Team Geophysics Element Case Histories

    DTIC Science & Technology

    1990-09-01

    34 on the surface by conducting one or more types of geophysical tests at that point. In the ideal case, the aquifer thickness and water quality would...The Geophysics Element has been deployed to participate in several major military exercises. Case historics of the Geophysics Element involvement in...ber who will advise the well drillers and reinterpret the geophysical survey results on the basis of drilling results, if necessary. This operating

  7. Field Geophysics at SAGE: Strategies for Effective Education

    NASA Astrophysics Data System (ADS)

    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

  8. Geology and Geophysical Surveys to Infer the Structure of the Upper San Pedro River Basin, Sonora, Mexico for Use in a Ground-Water-Flow Model

    NASA Astrophysics Data System (ADS)

    Pool, D.; Gray, F.; Callegary, J. B.

    2005-05-01

    Data on geology and geophysics in the San Pedro River Basin in Sonora, Mexico were combined to develop a three-dimensional conceptual model of the alluvial-fill aquifer in the basin that is being used to construct a regional ground-water-flow model. In Mexico, the headwater region of the river encompasses approximately 1,800 square kilometers of an ungaged catchment system. This feeds a 58 kilometer-long series of intermittent and perennial stream reaches in the United States that extend from just north of the international border to the town of St. David, Arizona. The river forms part of a north-south riparian corridor that provides habitat for more than 100 resident and 250 migratory bird species. Ground water in the basin is used extensively on both sides of the border and information on basin structure and composition will help to address questions regarding ground- and surface-water sustainability and planning. Interpretations of bedrock and alluvial-fill geometry indicate that a significant portion of the catchment area in Mexico is underlain by bedrock composed of highly indurated (compacted) Cretaceous sedimentary, volcanic, volcano-sedimentary, and granitic intrusive rocks. Aeromagnetic surveys were used to estimate depth to bedrock underlying alluvial sediments. Satellite photographs, older geologic maps, and recent field observations were used to delineate the boundaries between bedrock and alluvium. About 655 square kilometers, or 36 percent, of the Mexican portion of the river basin is underlain by alluvial fill. In the southern part of the study area, detailed information on thickness and composition of subsurface layers to depths of 500 meters was derived from drill logs. An extensive network of vertical electrical soundings covering much of the central part of the basin allowed for estimates of the location and thickness of clay layers that are confining units within the aquifer system. Across much of the area, the thickness of the silt and

  9. Optimization and geophysical inverse problems

    SciTech Connect

    Barhen, J.; Berryman, J.G.; Borcea, L.; Dennis, J.; de Groot-Hedlin, C.; Gilbert, F.; Gill, P.; Heinkenschloss, M.; Johnson, L.; McEvilly, T.; More, J.; Newman, G.; Oldenburg, D.; Parker, P.; Porto, B.; Sen, M.; Torczon, V.; Vasco, D.; Woodward, N.B.

    2000-10-01

    A fundamental part of geophysics is to make inferences about the interior of the earth on the basis of data collected at or near the surface of the earth. In almost all cases these measured data are only indirectly related to the properties of the earth that are of interest, so an inverse problem must be solved in order to obtain estimates of the physical properties within the earth. In February of 1999 the U.S. Department of Energy sponsored a workshop that was intended to examine the methods currently being used to solve geophysical inverse problems and to consider what new approaches should be explored in the future. The interdisciplinary area between inverse problems in geophysics and optimization methods in mathematics was specifically targeted as one where an interchange of ideas was likely to be fruitful. Thus about half of the participants were actively involved in solving geophysical inverse problems and about half were actively involved in research on general optimization methods. This report presents some of the topics that were explored at the workshop and the conclusions that were reached. In general, the objective of a geophysical inverse problem is to find an earth model, described by a set of physical parameters, that is consistent with the observational data. It is usually assumed that the forward problem, that of calculating simulated data for an earth model, is well enough understood so that reasonably accurate synthetic data can be generated for an arbitrary model. The inverse problem is then posed as an optimization problem, where the function to be optimized is variously called the objective function, misfit function, or fitness function. The objective function is typically some measure of the difference between observational data and synthetic data calculated for a trial model. However, because of incomplete and inaccurate data, the objective function often incorporates some additional form of regularization, such as a measure of smoothness

  10. Glacitectonic rafting and associated deformation of mid-Pleistocene glacigenic sediments, near Central Graben, central North Sea; results of a 2D High-Resolution Geophysical Survey

    NASA Astrophysics Data System (ADS)

    Vaughan-Hirsch, David

    2013-04-01

    Glacitectonic rafts are defined as dislocated slabs of bedrock or unconsolidated sediments, transported from their original position by glacial action. These relatively thin, slab-like bodies feature transport distances ranging from tens of meters to hundreds of kilometers. They occur as either single rafts, or multiple stacked bodies associated with a variety of ice-pushed landforms. Internally, rafts frequently appear undeformed although at a larger scale, they may be folded or cut by shear zones and brittle faults. However, the processes leading to the detachment, transport and subsequent emplacement of the rafts remain uncertain. This work describes the results of a geophysical 2D seismic survey of thrust-bound glacitectonic rafts and associated deformation structures, occurring within mid-Pleistocene glacigenic sediments of the Central Graben, central North Sea. The total shortened length of the rafted section is 2.4km, comprising a series of nine discrete rafts which individually range from 235m to 1018m in length. The principle basal detachment occurs at the erosive contact between Aberdeen Ground Formation and overlying Ling Bank Formation. The ice-proximal (northern) limit of rafting is defined by the presence of a large-scale palaeo-channel oriented perpendicular to the direction of rafting, composed of sediments of the Ling Bank Formation and the Forth Formation. The observed deformation structures infer a mean tectonic direction of 178°, indicating that they are associated with an active glacial advance from the north. The resulting deformation creates a minimum lateral shortening throughout the observed sequence of 35%, typifying a strongly compressional regieme associated with rafting. Throughout the surveyed area, structurally younger rafts are found to be emplaced towards the south, compared to the structurally older rafts which are emplaced towards the south-east. This distinction is suggested to be caused by early rafts creating an obstacle to

  11. Geophysical Survey of the 1978 Seismo-volcanic Crisis in the Asal-Ghoubbet Rift (Afar Depression, Djibouti) and the Post-rifting Deformations

    NASA Astrophysics Data System (ADS)

    Doubre, C.; Ruegg, J.; de Chabalier, J.; Vigny, C.; Jacques, E.

    2006-12-01

    In November 1978, a seismo-volcanic crisis occurred in the Asal-Ghoubbet Rift, which is located at the western termination of the oceanic Aden Ridge propagating inland into the Afar Depression and accommodates a large part of the divergent motion of the Arabia and Somalia plates. This episode offered the opportunity to study the rifting process controlling the evolution of a sub-aerial opening segment at the transition from continental break-up to oceanic spreading. This major crustal spreading episode started with two major earthquakes in the subaerial part of the rift (mb=5.3 and 5.0) and was followed by the week-long, basaltic fissure eruption of the Ardukoba at the western tip of the central volcanic chain. The geophysical survey carried out for the crisis was possible by means of the Arta Observatory in Djibouti within the framework of field surveys financed by the French agency CNRS-INSU. This allowed the measurements of the surface breaks (dry open fissures up to 100 m, normal fault throws up to 80 cm), the crustal deformation by geodetic networks and leveling (up to 2m of horizontal widening, 70 cm of inner-floor subsidence), and the evolution of the seismic activity (eastward migration along the Aden Ridge) associated with this rifting event. Elastic modeling shows that both the deformation pattern and the seismic activity can be explained by the aseismic intrusion of two dykes below the rift inner-floor. Subsequently, a continuous geodetic and seismic monitoring has been maintained and shows that the post-dyke injection evolution of the rift is dominated by two distinct periods. During the six first years (1979-1986), high rates of horizontal opening and slip of creeping normal faults accommodate the subsidence of the inner-floor surrimposed to the development of a 25 km-wide uplift. Since 1986-87, the strain rates have decreased and currently reach values consistent with long-term velocities deduced from morpho-tectonic studies. The evolution of the

  12. SAGE celebrates 25 years of learning geophysics by doing geophysics

    USGS Publications Warehouse

    Jiracek, G.R.; Baldridge, W.S.; Sussman, A.J.; Biehler, S.; Braile, L.W.; Ferguson, J.F.; Gilpin, B.E.; McPhee, D.K.; Pellerin, L.

    2008-01-01

    The increasing world demand and record-high costs for energy and mineral resources, along with the attendant environmental and climate concerns, have escalated the need for trained geophysicists to unprecedented levels. This is not only a national need; it's a critical global need. As Earth scientists and educators we must seriously ask if our geophysics pipeline can adequately address this crisis. One program that has helped to answer this question in the affirmative for 25 years is SAGE (Summer of Applied Geophysical Experience). SAGE continues to develop with new faculty, new collaborations, and additional ways to support student participation during and after SAGE. ?? 2008 Society of Exploration Geophysicists.

  13. Geophysics: Building E5032 decommissioning, Aberdeen Proving Ground

    SciTech Connect

    McGinnis, L.D.; Miller, S.F.

    1991-07-01

    integration of data from surveys using three geophysical technologies has provided information used to define the locations of buried utilities, tanks, vaults, and debris near building E5032 at the Aberdeen Proving Ground. Ground penetrating radar (GPR) profiles indicate the presence of buried pipes, tanks, reinforcement rods (rebar), and remnants of railroad tracks. A magnetic map constructed from a detailed magnetic survey on the north side of the building outlines buried iron-rich objects that are interpreted to be iron pipes, tank, and other debris of uncertain origin at relatively shallow depths. Horizontal electrical resistivity surveys and vertical electrical resistivity soundings essentially corroborated the findings obtained with the magnetometer and GPR. In addition, a highly resistance layer was observed on the east side of the building where a former railroad bed with a thick grave fill is believed to immediately underlie the lawn. The resistivity data show no evidence of a conductive leachate plume. Geophysical measurements from three techniques over a buried concrete slab approximately 130 ft north of Building E5032 give geophysical signatures interpreted to be due to the presence of a large iron tank or vault. An attempt was made to gather meaningful magnetic data on the east, west, and south sides of the building; however, the quality of subsurface interpretations in those areas was poor because of the influence of surficial iron lids, pipes, grates, and the effects of the corrugated iron building itself. 11 figs., 1 tab.

  14. Handbook of Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13(2), February 29, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-002 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1.

  16. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (6), June 30, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-005 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

  17. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 25(10), October 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-010 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1 . Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos

  18. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13(3), March 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-002 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid.

  19. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (7), July 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-007 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

  20. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (1), January 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-001 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1. Subscriptions to SEAN Bulletin are also available from AGU Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid.

  1. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13(9), September 30, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-013 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

  2. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (5), May 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-004 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

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

    NASA Astrophysics Data System (ADS)

    Reed, D. L.; Williams, R.

    2006-12-01

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

  4. Fast-Turnoff Transient Electro-Magnetic (TEM) geophysical survey in the Peña de Hierro ("Berg of Iron") field area of the Mars Analog Research and Technology Experiment (MARTE)

    NASA Astrophysics Data System (ADS)

    Jernsletten, J. A.

    2004-12-01

    This report describes the outcome of a Fast-Turnoff Transient Electro-Magnetic (TEM) geophysical survey carried out in the Peña de Hierro ("Berg of Iron") field area of the Mars Analog Research and Technology Experiment (MARTE), during May and June of 2003. The MARTE Peña de Hierro field area is located between the towns of Rio Tinto and Nerva in the Andalucia region of Spain. It is about one hour drive West of the city of Sevilla, and also about one hour drive North of Huelva. The high concentration of dissolved iron (and smaller amounts of other metals) in the very acidic water in the Rio Tinto area gives the water its characteristic wine red color, and also means that the water is highly conductive, and such an acidic and conductive fluid is highly suited for exploration by electromagnetic methods. This naturally acidic environment is maintained by bacteria in the groundwater and it is these bacteria that are the main focus of the MARTE project overall, and of this supporting geophysical work. It is the goal of this study to be able to map the subsurface extent of the high conductivity (low resistivity) levels, and thus by proxy the subsurface extent of the acidic groundwater and the bacteria populations. In so doing, the viability of using electromagnetic methods for mapping these subsurface metal-rich water bodies is also examined and demonstrated, and the geophysical data will serve to support drilling efforts. The purpose of this field survey was an initial effort to map certain conductive features in the field area, in support of the drilling operations that are central to the MARTE project. These conductive features include the primary target of exploration for MARTE, the very conductive acidic groundwater in the area (which is extremely rich in metals). Other conductive features include the pyretic ore bodies in the area, as well as extensive mine tailings piles.

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

    SciTech Connect

    Saunders, W.R.; Smith, S.; Gilmore, P.; Cox, S.

    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.

  6. MX Siting Investigation. Mineral Resources Survey, Seven Additional Valleys, Nevada/Utah Siting Area. Volume II.

    DTIC Science & Technology

    1981-06-23

    AO-AI13 14𔃾 ERTEC WESTERN INC LONG BEACH CA F/6 7/4 MX SITING INVESTIGATION. MINERAL RESOURCES SURVEY, SEVEN ADDITI-ETC(U) JUN Al F04704-80-C-OGO6...DTIC-DDA-2 FORM DOCUMENT PROCESSING SHEET DTIC ocT :g 70A -- ~’ .9 ’I K ii I / "~1 - i~ / . . ..1’ ~ ~- .. ~ ~1 I E-TR-50 MINERAL RESOURCES SURVEY...144 ERTEC WESTERN INC. LONG BEACH CA F/6 7/4 MX SITING INVESTIGATION. MINERAL RESOURCES SURVEY. SEVEN AOOITI-ETCIU) JUN 81 FON7O-80-C-0006

  7. HMF-Geophysics: A Model for Collaborative Research in Hydrogeophysics

    NASA Astrophysics Data System (ADS)

    Knight, R.; Crook, N.; Bales, R.; Moore, J.; Papanicolaou, T.; Welty, C.

    2008-05-01

    CUAHSI is developing, with the support of the NSF, a Hydrologic Measurement Facility (HMF). HMF-Geophysics is the near-surface geophysics module of HMF. Over the three years of the NSF grant (2005-08) we will determine, through broad community consultation, how best to utilize geophysical instrumentation and engage geophysical expertise in addressing key challenges in the hydrologic sciences. Our goal is to put in place the infrastructure needed to develop and maintain partnerships between the hydrologic and geophysical communities so that geophysical methods are used in a way that represents the state-of-the-science. Our current model consists of a central "node" that conducts feasibility studies to determine how/if geophysical methods could be of use in a hydrologic research project. In addition to the central node we have developed a system of affiliated nodes, individuals at 14 institutions who have committed to support HMF-Geophysics activities by offering equipment, software, and expertise. Once a feasibility study has shown the value of geophysics at a particular site, we match the hydrology PI with one of the nodes to develop the full-scale research project. We have conducted feasibility studies at 6 sites: Reynolds Creek Watershed, the H.J. Andrews Experimental Forest, and four WATERS test- beds, the latter are described below. The objective of the Baltimore test-bed is to quantify the urban water cycle, with an emphasis on groundwater, using the Gwynns Falls watershed as a pilot study area. Electrical resistivity imaging, ground penetrating radar, and seismic refraction were assessed as a means of determining depth to bedrock or to the water table within the riparian zone of urbanized streams. A regional time-lapse microgravity survey was conducted at the 200 sq- km watershed scale to infer the storage change in the underlying aquifers. Research in the Crown of the Continent test-bed in Montana is focused on understanding the interactions between the

  8. Integrated geophysical investigations of Main Barton Springs, Austin, Texas, USA

    NASA Astrophysics Data System (ADS)

    Saribudak, By Mustafa; Hauwert, Nico M.

    2017-03-01

    Barton Springs is a major discharge site for the Barton Springs Segment of the Edwards Aquifer and is located in Zilker Park, Austin, Texas. Barton Springs actually consists of at least four springs. The Main Barton Springs discharges into the Barton Springs pool from the Barton Springs fault and several outlets along a fault, from a cave, several fissures, and gravel-filled solution cavities on the floor of the pool west of the fault. Surface geophysical surveys [resistivity imaging, induced polarization (IP), self-potential (SP), seismic refraction, and ground penetrating radar (GPR)] were performed across the Barton Springs fault and at the vicinity of the Main Barton Springs in south Zilker Park. The purpose of the surveys was two-fold: 1) locate the precise location of submerged conduits (caves, voids) carrying flow to Main Barton Springs; and 2) characterize the geophysical signatures of the fault crossing Barton Springs pool. Geophysical results indicate significant anomalies to the south of the Barton Springs pool. A majority of these anomalies indicate a fault-like pattern, in front of the south entrance to the swimming pool. In addition, resistivity and SP results, in particular, suggest the presence of a large conduit in the southern part of Barton Springs pool. The groundwater flow-path to the Main Barton Springs could follow the locations of those resistivity and SP anomalies along the newly discovered fault, instead of along the Barton Springs fault, as previously thought.

  9. Fiber optic geophysical sensors

    DOEpatents

    Homuth, Emil F.

    1991-01-01

    A fiber optic geophysical sensor in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects.

  10. Integrated Geologic, Hydrologic, and Geophysical Investigations of the Chesapeake Bay Impact Structure, Virginia, USA: A Multi-Agency Program

    NASA Technical Reports Server (NTRS)

    Gohn, G. S.; Bruce, T. S.; Catchings, R. D.; Emry, S. R.; Johnson, G. H.; Levine, J. S.; McFarland, E. R.; Poag, C. W.; Powars, D. S.

    2001-01-01

    The Chesapeake Bay impact structure is the focus of an ongoing federal-state-local research program. Recent core drilling and geophysical surveys address the formative processes and hydrogeologic properties of this major "wet-target" impact. Additional information is contained in the original extended abstract.

  11. Beowawe geothermal-resource assessment. Final report. Shallow-hole temperature survey geophysics and deep test hole Collins 76-17

    SciTech Connect

    Jones, N.O.

    1983-03-01

    Geothermal resource investigation field efforts in the Beowawe Geysers Area, Eureka County, Nevada are described. The objectives included acquisition of geotechnical data for understanding the nature and extent of the geothermal resource boundaries south of the known resource area. Fourteen shallow (<500 feet) temperature-gradient holes plus geophysics were used to select the site for a deep exploratory well, the Collins 76-17, which was completed to a total depth of 9005 feet. Maximum downhole recorded temperature was 311/sup 0/F, but no flow could be induced.

  12. An Introduction to Using Surface Geophysics to Characterize Sand and Gravel Deposits

    USGS Publications Warehouse

    Lucius, Jeffrey E.; Langer, William H.; Ellefsen, Karl J.

    2007-01-01

    This report is an introduction to surface geophysical techniques that aggregate producers can use to characterize known deposits of sand and gravel. Five well-established and well-tested geophysical methods are presented: seismic refraction and reflection, resistivity, ground penetrating radar, time-domain electromagnetism, and frequency-domain electromagnetism. Depending on site conditions and the selected method(s), geophysical surveys can provide information concerning areal extent and thickness of the deposit, thickness of overburden, depth to the water table, critical geologic contacts, and location and correlation of geologic features. In addition, geophysical surveys can be conducted prior to intensive drilling to help locate auger or drill holes, reduce the number of drill holes required, calculate stripping ratios to help manage mining costs, and provide continuity between sampling sites to upgrade the confidence of reserve calculations from probable reserves to proved reserves. Perhaps the greatest value of geophysics to aggregate producers may be the speed of data acquisition, reduced overall costs, and improved subsurface characterization.

  13. An Introduction to Using Surface Geophysics to Characterize Sand and Gravel Deposits

    USGS Publications Warehouse

    Lucius, Jeffrey E.; Langer, William H.; Ellefsen, Karl J.

    2006-01-01

    This report is an introduction to surface geophysical techniques that aggregate producers can use to characterize known deposits of sand and gravel. Five well-established and well-tested geophysical methods are presented: seismic refraction and reflection, resistivity, ground penetrating radar, time-domain electromagnetism, and frequency-domain electromagnetism. Depending on site conditions and the selected method(s), geophysical surveys can provide information concerning aerial extent and thickness of the deposit, thickness of overburden, depth to the water table, critical geologic contacts, and location and correlation of geologic features. In addition, geophysical surveys can be conducted prior to intensive drilling to help locate auger or drill holes, reduce the number of drill holes required, calculate stripping ratios to help manage mining costs, and provide continuity between sampling sites to upgrade the confidence of reserve calculations from probable reserves to proved reserves. Perhaps the greatest value of geophysics to aggregate producers may be the speed of data acquisition, reduced overall costs, and improved subsurface characterization.

  14. Geophysical Summer Field Camp: Answering questions about the subsurface for the local community

    NASA Astrophysics Data System (ADS)

    van Wijk, K.; Batzle, M.; Liberty, L.; Raynolds, R.

    2008-12-01

    Summer Geophysics Field Camp is part of the core requirement for undergraduate Geophysics majors at Boise State University (CSM), as well as at Colorado School of Mines (CSM). We have found it to be most effectively taught when the target of the camp involves answering questions, which impact society. For example, currently the CSM/BSU geophysics summer camp focuses on ground water resources and geothermal potential in the Upper Arkansas River Basin, a part of the Rio Grande Rift system in Chaffee County, Colorado. A prime goal is to train students how to combine diverse sources of information into a unified interpretation: Students examine lithologies and structures on the periphery of the basin. Cross sections are constructed to predict the geophysical signature. Geophysical tools then are used to ascertain the gross structure and examine subsurface conditions in greater detail. These tools include surveying, regional gravity, deep and shallow seismic surveys, magnetics, DC resistivity, Ground Penetrating Radar, electromagnetics, hydrochemistry, and karaoke. While BSU and CSM own a considerable amount of geophysical hardware, our field camps are only possible because of extensive support by corporations and governmental agencies. In addition, the Society of Exploration Geohysics (SEG) Foundation provides financial support, Chaffee County assists with housing costs, and local land owners provide open access. In turn, the field camp results aid the community of Chaffee County in assessing their water resources for long term growth planning, as well as understanding the geothermal potential for hydroelectric power generation. BSU is currently exploring with the SEG Foundation under the Geophysicists Without Borders program to apply this model of combined education and social outreach in the form a geophysics camp for Southeast Asia, where we propose to study geohazards,geoarcheology and groundwater issues.

  15. Serious games for Geophysics

    NASA Astrophysics Data System (ADS)

    Lombardo, Valerio; Rubbia, Giuliana

    2015-04-01

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

  16. Survey of residue levels of organic solvents in "existing food additives" and health food materials by head-space GC.

    PubMed

    Uematsu, Yoko; Ogimoto, Mami; Suzuki, Kumi; Kabashima, Junichirou; Ito, Koichi; Nakazato, Mitsuo

    2008-01-01

    Organic solvent residue levels in "Existing Food Additives" (n=145), health food materials (n=23), and commercial health food products (n=19) were surveyed. Ethanol was the dominant solvent found in the samples, suggesting its use in the manufacturing process. Methanol, acetone, 2-propanol and ethyl acetate was also found. No residual solvent exceeded the limits set by the Food Sanitation Law.

  17. 78 FR 38713 - Additional Documents Available for Public Review Related to Willingness To Pay Survey for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-27

    ... Review Report, the Focus Group and Cognitive Interview Report and the Description of Hydrological... provide useful information to interested parties regarding the development and design of the survey instruments proposed for this project. Full transcripts of the focus groups and cognitive interviews were...

  18. A survey of z > 5.7 quasars in the sloan digital sky survey. 4. discovery of seven additional quasars

    SciTech Connect

    Fan, Xiao-Hui; Strauss, Michael A.; Richards, Gordon T.; Hennawi, Joseph F.; Becker, Robert H.; White, Richard L.; Diamond-Stanic, Aleksandar M.; onley, Jennifer L.D; Jiang, Lin-Hua; Kim, J.Serena; Vestergaard, Marianne; Young, Jason E.; Gunn, James E.; Lupton, Robert H.; Knapp, Gillian R.; Schneider, Donald P.; Brandt, W.N.; Bahcall, Neta A.; Barentine, J.C.; Brinkmann, J.; Brewington, Howard J.; /Arizona U., Astron. Dept. - Steward Observ. /Princeton U. Observ. /Johns Hopkins U. /UC, Berkeley, Astron. Dept. /UC, Davis /LLNL, Livermore /Baltimore, Space Telescope Sci. /Penn State U., Astron. Astrophys. /Apache Point Observ. /Tokyo U., ICRR /Mt. Suhora Observ., Cracow /Fermilab /Garching, Max Planck Inst., MPE

    2005-12-01

    We present the discovery of seven quasars at z > 5.7, selected from {approx}2000 deg{sup 2} of multicolor imaging data of the Sloan Digital Sky Survey (SDSS). The new quasars have redshifts z from 5.79 to 6.13. Five are selected as part of a complete flux-limited sample in the SDSS Northern Galactic Cap; two have larger photometric errors and are not part of the complete sample. One of the new quasars, SDSS J1335+3533 (z = 5.93), exhibits no emission lines; the 3-{sigma} limit on the rest-frame equivalent width of Ly{alpha} + NV line is 5 {angstrom}. It is the highest redshift lineless quasar known, and could be a gravitational lensed galaxy, a BL Lac object or a new type of quasar. Two new z > 6 quasars, SDSS 1250+3130 (z = 6.13) and SDSS J1137+3549 (z = 6.01), show deep Gunn-Peterson absorption gaps in Ly{alpha}. These gaps are narrower the complete Gunn-Peterson absorption troughs observed among quasars at z > 6.2 and do not have complete Ly{beta} absorption.

  19. Air-depolyable geophysics package

    SciTech Connect

    Hunter, S.L.; Harben, P.E.

    1993-11-01

    We are using Lawrence Livermore National Laboratory`s (LLNL`s) diverse expertise to develop a geophysical monitoring system that can survive being dropped into place by a helicopter or airplane. Such an air-deployable system could significantly decrease the time and effort needed to set up such instruments in remote locations following a major earthquake or volcanic eruption. Most currently available geophysical monitoring and survey systems, such as seismic monitoring stations, use sensitive, fragile instrumentation that requires personnel trained and experienced in data acquisition and field setup. Rapid deployment of such equipment can be difficult or impossible. Recent developments in low-power electronics, new materials, and sensors that are resistant to severe impacts have made it possible to develop low-cost geophysical monitoring packages for rapid deployment missions. Our strategy was to focus on low-cost battery-powered systems that would have a relatively long (several months) operational lifetime. We concentrated on the conceptual design and engineering of a single-component seismic system that could survive an air-deployment into an earth material, such as alluvium. Actual implementation of such a system is a goal of future work on this concept. For this project, we drew on LLNL`s Earth Sciences Department, Radio Shop, Plastics Shop, and Weapons Program. The military has had several programs to develop air-deployed and cannon-deployed seismometers. Recently, a sonobuoy manufacturer has offered an air-deployable geophone designed to make relatively soft landings.

  20. Applying geophysical surveys for studying subsurface geology of monogenetic volcanic fields: the example of La Garrotxa Volcanic Field (NE of Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Bolós, Xavier; Barde-Cabusson, Stéphanie; Pedrazzi, Dario; Martí, Joan; Casas, Albert; Lovera, Raúl; Nadal-Sala, Daniel

    2014-05-01

    Improving knowledge of the shallowest part of the feeding system of monogenetic volcanoes and the relationship with the subsurface geology is an important task. We applied high-precision geophysical techniques that are self-potential and electrical resistivity tomography, for the exploration of the uppermost part of the substrate of La Garrotxa Volcanic Field, which is part of the European Cenozoic Rift System. Previous geophysical studies carried out in the same area at a less detailed scale were aimed at identifying deeper structures, and together constitute the basis to establish volcanic susceptibility in La Garrotxa. Self-potential study allowed identifying key areas where electrical resistivity tomography could be conducted. Dykes and faults associated with several monogenetic cones were identified through the generation of resistivity models. The combined results confirm that shallow tectonics controlling the distribution of the foci of eruptive activity in this volcanic zone mainly correspond to NNW-SSE and accessorily by NNE-SSW Neogene extensional fissures and faults and concretely show the associated magmatic intrusions. These studies show that previous alpine tectonic structures played no apparent role in controlling the loci of this volcanism. Furthermore, the results obtained show that the changes in eruption dynamics occurring at different vents located at relatively short distances in this volcanic area can be controlled by shallow stratigraphical, structural, and hydrogeological features underneath these monogenetic volcanoes. This study was partially funded by the Beca Ciutat d'Olot en Ciències Naturals and the European Commission (FT7 Theme: ENV.2011.1.3.3-1; Grant 282759: "VUELCO").

  1. Geophysics in INSPIRE

    NASA Astrophysics Data System (ADS)

    Sőrés, László

    2013-04-01

    INSPIRE is a European directive to harmonize spatial data in Europe. Its' aim is to establish a transparent, multidisciplinary network of environmental information by using international standards and OGC web services. Spatial data themes defined in the annex of the directive cover 34 domains that are closely bundled to environment and spatial information. According to the INSPIRE roadmap all data providers must setup discovery, viewing and download services and restructure data stores to provide spatial data as defined by the underlying specifications by 2014 December 1. More than 3000 institutions are going to be involved in the progress. During the data specification process geophysics as an inevitable source of geo information was introduced to Annex II Geology. Within the Geology theme Geophysics is divided into core and extended model. The core model contains specifications for legally binding data provisioning and is going to be part of the Implementation Rules of the INSPIRE directives. To minimize the work load of obligatory data transformations the scope of the core model is very limited and simple. It covers the most essential geophysical feature types that are relevant in economic and environmental context. To fully support the use cases identified by the stake holders the extended model was developed. It contains a wide range of spatial object types for geophysical measurements, processed and interpreted results, and wrapper classes to help data providers in using the Observation and Measurements (O&M) standard for geophysical data exchange. Instead of introducing the traditional concept of "geophysical methods" at a high structural level the data model classifies measurements and geophysical models based on their spatial characteristics. Measurements are classified as geophysical station (point), geophysical profile (curve) and geophysical swath (surface). Generic classes for processing results and interpretation models are curve model (1D), surface

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

    NASA Astrophysics Data System (ADS)

    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. High temperature geophysical instrumentation

    SciTech Connect

    Hardee, H.C.

    1988-06-01

    The instrumentation development program was to proceed in parallel with scientific research and was driven by the needs of researchers. The development of these instruments has therefore included numerous geophysical field tests, many of which have resulted in the publication of scientific articles. This paper is a brief summary of some of the major geophysical instruments that have been developed and tested under the High Temperature Geophysics Program. These instruments are briefly described and references are given for further detailed information and for scientific papers that have resulted from the use of these instruments. 9 refs., 14 figs.

  4. Fiber optic geophysical sensors

    DOEpatents

    Homuth, E.F.

    1991-03-19

    A fiber optic geophysical sensor is described in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects. 2 figures.

  5. New Geophysical Observatory in Uruguay

    NASA Astrophysics Data System (ADS)

    Sanchez Bettucci, L.; Nuñez, P.; Caraballo, R. R.; Ogando, R.

    2013-05-01

    In 2011 began the installation of the first geophysical observatory in Uruguay, with the aim of developing the Geosciences. The Astronomical and Geophysical Observatory Aiguá (OAGA) is located within the Cerro Catedral Tourist Farm (-34 ° 20 '0 .89 "S/-54 ° 42 '44.72" W, h: 270m). This has the distinction of being located in the center of the South Atlantic Magnetic Anomaly. Geologically is emplaced in a Neoproterozoic basement, in a region with scarce anthropogenic interference. The OAGA has, since 2012, with a GSM-90FD dIdD v7.0 and GSM-90F Overhauser, both of GEM Systems. In addition has a super-SID receiver provided by the Stanford University SOLAR Center, as a complement for educational purposes. Likewise the installation of a seismograph REF TEK-151-120A and VLF antenna is being done since the beginning of 2013.

  6. Preliminary Investigation of Paleochannels and Groundwater Specific Conductance using Direct-Current Resistivity and Surface-Wave Seismic Geophysical Surveys at the Standard Chlorine of Delaware, Inc., Superfund Site, Delaware City, Delaware, 2008

    USGS Publications Warehouse

    Degnan, James R.; Brayton, Michael J.

    2010-01-01

    The U.S. Geological Survey (USGS), in cooperation with Region III of the U.S. Environmental Protection Agency (USEPA) and the State of Delaware, is conducting an ongoing study of the water-quality and hydrogeologic properties of the Columbia and Potomac aquifers and the extent of cross-aquifer contamination with benzene; chlorobenzene; 1,2-dichlorobenzene; 1,4-dichlorobenzene; and hydrogen chloride (hydrochloric acid when dissolved in water) in the vicinity of the Standard Chlorine of Delaware, Inc. (SCD), Superfund Site, Delaware City, Delaware. Surface geophysical surveys and well data were used to identify and correlate low-permeability units (clays) across the site and to search for sand and gravel filled paleochannels that are potential conduits and receptors of contaminated groundwater and (or) Dense Non-Aqueous Phase Liquid (DNAPL) contaminants. The combined surveys and well data were also used to characterize areas of the site that have groundwater with elevated (greater than 1,000 microsiemens per centimeter) specific conductance (SC) as a result of contamination. The most electrically conductive features measured with direct-current (DC) resistivity at the SCD site are relatively impermeable clays and permeable sediment that are associated with elevated SC in groundwater. Many of the resistive features include paleochannel deposits consisting of coarse-grained sediments that are unsaturated, have low (less than 200 microsiemens per centimeter) SC pore water, or are cemented. Groundwater in uncontaminated parts of the Columbia aquifer and of the Potomac aquifer has a low SC. Specific-conductance data from monitoring wells at the site were used to corroborate the DC-resistivity survey results. For comparison with DC-resistivity surveys, multi-channel analysis of surface wave (MASW) surveys were used and were able to penetrate deep enough to measure the Columbia aquifer, which is known to have elevated SC in some places. MASW survey results respond to solid

  7. Geophysical investigation at Fort Detrick Maryland. Final report

    SciTech Connect

    Llopis, J.L.; Simms, J.E.

    1993-07-01

    Results of a comprehensive, integrated geophysical investigation of 15 suspected disposal areas at Area B, Fort Detrick, Maryland, are presented. Between 1943 and 1969, Fort Detrick served as the nation's center for military offensive and defensive biological research. As a result of this activity, chemically and biologically contaminated materials were generated and disposed in burial pits at Site B. Based on historical and visual information, 15 sites suspected of containing burial pits were selected to be examined in greater detail using geophysical methods. The geophysical investigations were designed to detect anomalous conditions indicative of past disposal activities. The geophysical program included electromagnetic (EM), magnetic, ground penetrating radar (GPR), and seismic refraction methods. Anomalous conditions were found at several of the sites tested and noted. The anomalous conditions may have resulted from the presence of buried material or from physical and/or chemical soil changes caused by disposal activities.... Geophysics, Electromagnetics ground penetrating radar, Geophysical surveys, Magnetics, Seismic refraction.

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

    NASA Astrophysics Data System (ADS)

    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!

  9. Geophysical investigation at US Army Materials Technology Laboratory, Massachusetts. Final report

    SciTech Connect

    Llopis, J.L.; Simms, J.E.

    1993-11-01

    Results of a comprehensive, integrated geophysical investigation at 5 sites at the U.S. Army Materials Technology Laboratory (MTL) located in Watertown, MA, are presented. In 1960, the Army's first materials research reactor was completed at MTL, which was used actively in molecular and atomic structure research activities until 1970, when it was deactivated. In addition to the research reactor were facilities that stored and handled depleted uranium (DU). In 1989, the Commission on Base Realignment and Closure recommended that MTL be closed. The MTL closure program is being supervised by the U.S. Army Environmental Center. As part of the MTL closure program, any previously contaminated sites must be identified. Based on historical information, 5 sites were selected at MTL to be examined in further detail using geophysical methods. The geophysical investigation was designed to detect and delineate anomalous conditions indicative of buried waste, waste containers, fuel storage tanks, and unmapped drain or sewer lines having the potential of carrying wastes off the site. Electromagnetics, Geophysics, Magnetics, Geophysical surveys, Ground penetrating, Radar.

  10. New geophysical views of Mt.Melbourne Volcano (East Antarctica)

    NASA Astrophysics Data System (ADS)

    Armadillo, E.; Gambetta, M.; Ferraccioli, F.; Corr, H.; Bozzo, E.

    2009-05-01

    Mt. Melbourne volcano is located along the transition between the Transantarctic Mountains and the West Antarctic Rift System. Recent volcanic activity is suggested by the occurrence of blankets of pyroclastic pumice and scoria fall around the eastern and southern flanks of Mt Melbourne and by pyroclastic layers interbedded with the summit snows. Geothermal activity in the crater area of Mount Melbourne may be linked to the intrusion of dykes within the last 200 years. Geophysical networks suggest that Mount Melbourne is a quiescent volcano, possibly characterised by slow internal dynamics. During the 2002-2003 Italian Antarctic campaign a high-resolution aeromagnetic survey was performed within the TIMM (Tectonics and Interior of Mt. Melbourne area) project. This helicopter-borne survey was flown at low-altitude and in drape-mode configuration (305 m above terrain) with a line separation less than 500 m. Our new high-resolution magnetic maps reveal the largely ice-covered magmatic and tectonic patters in the Mt. Melbourne volcano area. Additionally, in the frame of the UK-Italian ISODYN-WISE project (2005-06), an airborne ice-sounding radar survey was flown. We combine the sub-ice topography with images and models of the interior of Mt. Melbourne volcano, as derived from the high resolution aeromagnetic data and land gravity data. Our new geophysical maps and models also provide a new tool to study the regional setting of the volcano. In particular we re-assess whether there is geophysical evidence for coupling between strike-slip faulting, the Terror Rift, and Mount Melbourne volcano.

  11. Survey of the anticoccidial feed additive nicarbazin (as dinitrocarbanilide residues) in poultry and eggs.

    PubMed

    Danaher, Martin; Campbell, Katrina; O'Keeffe, Michael; Capurro, Emiliana; Kennedy, Glenn; Elliott, Christopher T

    2008-01-01

    A survey was carried out on the occurrence of dinitrocarbanilide (DNC), the marker residue for nicarbazin, in poultry produced in Ireland during 2002-2004. Liver (n = 736) and breast muscle samples (n = 342) were tested. DNC residues were found in 40 and 26% of liver and breast muscle samples at levels greater than 12.5 and 5 microg kg(-1), respectively. DNC residues were found at >200 microg kg(-1) in 12 and 0% of liver and muscle samples, respectively. Samples of breast muscle (n = 217) imported from 11 countries were also tested for DNC residues. A lower incidence of DNC residues (6%) was found in imported breast muscle. Egg samples (n = 546) were tested and DNC residues were found in nine samples, with levels ranging between 14 and 122 microg kg(-1). Analysis of poultry, carried out as part of official food inspection in the period 2004-2006, indicated a reduction in the number of broiler liver samples containing DNC at >200 microg kg(-1), to approximately 7%. Low levels of DNC residues continue to be found in <2% of egg samples.

  12. Phillips Laboratory Geophysics Scholar Program

    DTIC Science & Technology

    1993-09-30

    research at Phillips Laboratory . Research sponsored by Air Force Geophysics Laboratory ...Geophysics Laboratory (now the Phillips Laboratory , Geophysics Directorate), United States Air Force for its sponsorship of this research through the Air ...September 1993 Approved for public release; distribution unlimited PHILLIPS LABORATORY Directorate of Geophysics AIR FORCE MATERIEL COMMAND

  13. Risk assessment of additives through soft drinks and nectars consumption on Portuguese population: a 2010 survey.

    PubMed

    Diogo, Janina S G; Silva, Liliana S O; Pena, Angelina; Lino, Celeste M

    2013-12-01

    This study investigated whether the Portuguese population is at risk of exceeding ADI levels for acesulfame-K, saccharin, aspartame, caffeine, benzoic and sorbic acid through an assessment of dietary intake of additives and specific consumption of four types of beverages, traditional soft drinks and soft drinks based on mineral waters, energetic drinks, and nectars. The highest mean levels of additives were found for caffeine in energetic drinks, 293.5mg/L, for saccharin in traditional soft drinks, 18.4 mg/L, for acesulfame-K and aspartame in nectars, with 88.2 and 97.8 mg/L, respectively, for benzoic acid in traditional soft drinks, 125.7 mg/L, and for sorbic acid in soft drinks based on mineral water, 166.5 mg/L. Traditional soft drinks presented the highest acceptable daily intake percentages (ADIs%) for acesulfame-K, aspartame, benzoic and sorbic acid and similar value for saccharin (0.5%) when compared with soft drinks based on mineral water, 0.7%, 0.08%, 7.3%, and 1.92% versus 0.2%, 0.053%, 0.6%, and 0.28%, respectively. However for saccharin the highest percentage of ADI was obtained for nectars, 0.9%, in comparison with both types of soft drinks, 0.5%. Therefore, it is concluded that the Portuguese population is not at risk of exceeding the established ADIs for the studied additives.

  14. Landslide susceptibility assessment in ash-fall pyroclastic deposits surrounding Mount Somma-Vesuvius: Application of geophysical surveys for soil thickness mapping

    NASA Astrophysics Data System (ADS)

    De Vita, P.; Agrello, D.; Ambrosino, F.

    2006-06-01

    Along the steep slopes of the carbonate mountains that surround the Campanian Plain and Mount Somma-Vesuvius, rainfall-triggered debris slides occur in unconsolidated ash-fall pyroclastic deposits. The initial debris slides evolve into debris flows that often cause significant property damage and loss of human life in the towns located at the foot of the slopes. In this particular geological situation, the pyroclastic soil thickness, the slope angle, and the morphological variations of the slope profile are the most important factors that contribute to landslide susceptibility. In this paper, the results of an experimental application of shallow resistivity and refraction seismic soundings in mapping the thickness of pyroclastic soils are presented. These geophysical methods are proposed as low-cost and versatile methods to be used in the difficult morphological conditions of the steep slopes in which debris-slides initiate. The methods have been used experimentally in a sample area located on the upper slope of Mount Pizzo d'Alvano, from which debris flows initiated that dramatically hit the town of Sarno on 5-6 May 1998. The inversion of geoelectrical soundings has been calibrated with resistivity values measured directly on pyroclastic outcrops and with soil thickness estimations derived from refraction seismic soundings and from the application of a mobile dynamic penetrometer. The results of the field experimentation can be summarised as follows: (i) unconsolidated ash-fall pyroclastic deposits, ranging in particle size from fine ash to lapilli, can be differentiated from fractured carbonate bedrock by means of electrical resistivity and velocity values of longitudinal seismic waves; (ii) thickness of ash-fall pyroclastic soils can be empirically related to the slope angle using an inverse relationship; and (iii) the empirical model has been applied to Digital Elevation Model data, allowing pyroclastic soil thickness mapping in the sample area.

  15. High-resolution geophysical data collected offshore of Fire Island, New York in 2011, U.S. Geological Survey Field Activity 2011-005-FA.

    USGS Publications Warehouse

    Denny, Jane F.; Schwab, William C.; Baldwin, Wayne E.; Moore, Eric; Bergeron, Emile M.

    2015-01-01

    The U.S. Geological Survey (USGS) mapped approximately 336 square kilometers of the lower shoreface and inner-continental shelf offshore of Fire Island, New York in 2011 using interferometric sonar and high-resolution chirp seismic-reflection systems. These spatial data support research on the Quaternary evolution of the Fire Island coastal system and provide baseline information for research on coastal processes along southern Long Island.

  16. GIS of selected geophysical and core data in the northern Gulf of Mexico continental slope collected by the U.S. Geological Survey

    USGS Publications Warehouse

    Twichell, David C.; Cross, VeeAnn A.; Paskevich, Valerie F.; Hutchinson, Deborah R.; Winters, William J.; Hart, Patrick E.

    2006-01-01

    Since 1982 the U. S. Geological Survey (USGS) has collected a large amount of surficial and shallow subsurface geologic information in the deep-water parts of the US EEZ in the northern Gulf of Mexico. These data include digital sidescan sonar imagery, digital seismic-reflection data, and descriptions and analyses of piston and gravity cores. The data were collected during several different projects that addressed surficial and shallow subsurface geologic processes. Some of these datasets have already been published, but the growing interest in the occurrence and distribution of gas hydrates in the Gulf of Mexico warrants integrating these existing USGS datasets and associated interpretations into a Geographic Information System (GIS) to provide regional background information for ongoing and future gas hydrate research. This GIS is organized into five different components that contain (1) information needed to develop an assessment of gas hydrates, (2) background information for the Gulf of Mexico, (3) cores collected by the USGS, (4) seismic surveys conducted by the USGS, and (5) sidescan sonar surveys conducted by the USGS. A brief summary of the goals and findings of the USGS field programs in the Gulf of Mexico is given in the Geologic Findings section, and then the contents of each of the five data categories are described in greater detail in the GIS Data Catalog section.

  17. Continued geophysical logging near the GMH Electronics National Priorities List Superfund site near Roxboro, North Carolina

    USGS Publications Warehouse

    Antolino, Dominick J.; Chapman, Melinda J.

    2017-01-06

    The U.S. Geological Survey South Atlantic Water Science Center collected borehole geophysical logs and images and continuous water-level data near the GMH Electronics National Priorities List Superfund site near Roxboro, North Carolina, during December 2012 through July 2015. Previous work by the U.S. Geological Survey South Atlantic Water Science Center at the site involved the collection of borehole geophysical log data in 15 wells, in addition to surface geologic mapping and passive diffusion bag sampling. In a continued effort to assist the U.S. Environmental Protection Agency in developing a conceptual groundwater model to assess current contaminant distribution and future migration of contaminants, more than 900 subsurface features (primarily fracture orientations) in 10 open borehole wells were delineated and continuous water-level data information from 14 monitoring wells within close proximity of the initially drilled boreholes was collected to observe any induced water-level fluctuations during drilling operations

  18. Geophysical investigations at ORNL solid waste storage area 3

    SciTech Connect

    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.

  19. Upgrade to MODFLOW-GUI; addition of MODPATH, ZONEBDGT, and additional MODFLOW packages to the U.S. Geological Survey MODFLOW-96 Graphical-User Interface

    USGS Publications Warehouse

    Winston, R.B.

    1999-01-01

    This report describes enhancements to a Graphical-User Interface (GUI) for MODFLOW-96, the U.S. Geological Survey (USGS) modular, three-dimensional, finitedifference ground-water flow model, and MOC3D, the USGS three-dimensional, method-ofcharacteristics solute-transport model. The GUI is a plug-in extension (PIE) for the commercial program Argus ONEe. The GUI has been modified to support MODPATH (a particle tracking post-processing package for MODFLOW), ZONEBDGT (a computer program for calculating subregional water budgets), and the Stream, Horizontal-Flow Barrier, and Flow and Head Boundary packages in MODFLOW. Context-sensitive help has been added to make the GUI easier to use and to understand. In large part, the help consists of quotations from the relevant sections of this report and its predecessors. The revised interface includes automatic creation of geospatial information layers required for the added programs and packages, and menus and dialog boxes for input of parameters for simulation control. The GUI creates formatted ASCII files that can be read by MODFLOW-96, MOC3D, MODPATH, and ZONEBDGT. All four programs can be executed within the Argus ONEe application (Argus Interware, Inc., 1997). Spatial results of MODFLOW-96, MOC3D, and MODPATH can be visualized within Argus ONEe. Results from ZONEBDGT can be visualized in an independent program that can also be used to view budget data from MODFLOW, MOC3D, and SUTRA. Another independent program extracts hydrographs of head or drawdown at individual cells from formatted MODFLOW head and drawdown files. A web-based tutorial on the use of MODFLOW with Argus ONE has also been updated. The internal structure of the GUI has been modified to make it possible for advanced users to easily customize the GUI. Two additional, independent PIE?s were developed to allow users to edit the positions of nodes and to facilitate exporting the grid geometry to external programs.

  20. Geophysical Fiber Interferometer Gyroscope.

    DTIC Science & Technology

    1979-12-31

    gravitational antenna. Basically, their device was a Twyman -Green laser interferometer that was allegedly well-isolated from its thermal and...r ~AD-AO92 913 UTAH UNIV RESEARCH INST SALT LAKE CITY GEOSPACE SCIE-EYC F/B 20/6 GEOPHYSICAL FIBER INTERFEROMETER GYROSCOPE(U) .S DEC 79 L 0 WEAVER...ACCESSION no: S, 111CIPIENT’S CATALOG NUMBER AF6ii M_ __ _ __I_ _ 4. TItLIL (eovm4jk"IU .TYEo nPaTawn.ocoet GEOPHYSICAL FIBER INTERFEROMETER GYROSCOPE. / 9

  1. Teaching oriented geophysical software

    NASA Astrophysics Data System (ADS)

    Pinto, Victor; Rivero, Lluis; Casas, Albert

    2000-08-01

    Interactive teaching techniques encourage students to adopt an active role in their education and should therefore be used at different levels of the teaching sequence. In order to mitigate the lack of educational software for Applied Geophysics, a fully interactive graphic software has been developed. The program is written in Visual Basic with some subroutines in FORTRAN and is designed for IBM-PC microcomputers using a Windows environment. The program offers the majority of the processes involved in geophysical data handling, modelling, tutorials, and instrument simulators.

  2. Geological Mapping Using Legacy Geophysical Data in Las Vegas Valley

    NASA Astrophysics Data System (ADS)

    Donovan, D.; O'Donnell, J.; McLin, K.

    2014-12-01

    In 2008-2011, Clark County, Building Department contracted with Optim to collect 10,700 Reflection Microtremor (ReMi) 600 ft seismic lines that cover most of the metropolitan area of Las Vegas and other outlying communities such as Moapa, Laughlin, Primm, and Coyote Spring. The County completed their goal of characterizing seismic susceptibility of the top 100 ft and the results are posted at http://gisgate.co.clark.nv.us/openweb/. The research question of the authors is: What additional geologic information can be inferred from the data, either through reprocessing, cross correlation of drill hole data or additional data collection? An advantage of geophysical data is that it can be reprocessed to provide additional insight into the local geologic setting. The interpretation is also improved if combined with drill hole data and / or hydrologic information. It should be noted that there is also legacy geophysical data in limited areas collected by the USGS, primarily in conjunction with water well drilling, where some of the ReMi seismic data was collected. An unexpected result of the ReMi survey was a clear delineation of current and paleo channels in Laughlin, Moapa, and Las Vegas. The geometry of the paleochanel, of the Colorado River, is well away from the current position. however the signal is very similar to modern streams such as the Muddy River. Although the surficial geologic mapping in Las Vegas Valley was very detailed, and importantly, was performed prior to development; the new geophysical data provides better details of the lithologic properties of the units. That is it may be an excellent basis for remapping for specific properties related to engineering and hydrologic modeling.

  3. Selected physical properties of rocks from the Baid al Jimalah West tungsten deposit, Kingdom of Saudi Arabia, and recommendations for geophysical surveys

    USGS Publications Warehouse

    Gettings, M.E.

    1983-01-01

    Bulk density and magnetic susceptibility of 11 outcrop samples representing the Proterozoic lithologic units at the Baid al Jimalah West tungsten deposit, Kingdom of Saudi Arabia were measured. Induced polarization response, apparent resistivity, and electromagnetic conductivity were determined for four specimens of the sample suite. Measurements show that there is a negative density contrast of about -0.17 g-cm^-3 between metasedimentary rocks of the Murdama group and the Bald al Jimalah graaite and that this contrast decreases with increasing mineralization of the granite. Similarly, the bulk magnetic susceptibility of the granite is about one-third that of the Murdama rocks for this sample suite; however, magnetic susceptibility increases with increasing mineralization in the granite specimens. Electromagnetic conductivities are uniformly low, in part because the specimens are weathered, but probably also because intense silicification accompanies the mineralization. Induced polarization chargeability increases in the granitic specimens with increasing mineralization and reflects higher percentages of sulfide minerals. Chargeability for the mineralized rocks is about four times higher than for the Murdama host rocks, and apparent resistivity values are about one-fifth the values of host rocks. Based on these results, it is recommended that during reconnaissance exploration of the area 15 detailed high-precision gravity profiles at 10 m to 50 m station spacing and eight induced polarization dipole-dipole profiles at 25 m dipole spacing and maximum 'n' of 6 be measured. To help define subsurface structure, a high-precision, ground-magnetic survey (map at 2-gamma contour interval) and a four-channel gamma ray spectrometric survey on a 25x50 m grid covering the area of the profiles are recommended.

  4. Survey and Interpretation Geophysical of Magnetic Isochrones 4n.2 a 2A.3 (7.9 3.6 Ma) in the Central Part of the Rivera Plate

    NASA Astrophysics Data System (ADS)

    Perez, D. A.; Mortera-Gutierrez, C. A.; Bandy, W. L.; Valle, S.

    2013-05-01

    This study shows the results of six campaigns marine geophysics BABRIP06 in 2006, MAMRIV07 in 2007, MAMRIV08 in 2008, GUAYRIV10 in 2010, BATIBAJA11 in 2011 and MAMRIV12 in 2012, in the abyssal plain in the East Pacific Rise (EPR), on board the UNAM vessel, B/O El Puma. The oceanographic campaigns single beam bathymetric data collected and marine magnetic data. The results allow analyze and study the magnetic texture in the central north of the Rivera plate associated with geological structures and behavior of the seafloor to the isochronous 5A. The systematic survey of the magnetic data provided high resolution on the guidelines of the magnetic anomalies associated with cortical spreading between 7.9 and 3.6 Ma, generated by the northern segment of the East Pacific Rise (EPR), between the Rivera and Tamayo Oceanic Transformants. Multibeam bathymetry data and the acoustic reflectivity of the six campaigns are correlated with the geometry of the magnetic anomalies and seismic reflection profiles to understand the processes that formed the highlight recreational ocean in this area. The main results in this study is the identification of continuous magnetic isochrones 4n.2 to 2A.3, magnetic anomalies associated with seamounts, the geometry of the isochrones associated with a propagator and magnetic anomaly identification of isochronous 3n.3 had not been demonstrated by other oceanographic surveys. Possibly oceanic spreading rate was slower during these epochs and the identification of a cross anomaly was due to a fracture zone that generated the propagator.

  5. A Ground Penetrating Radar (GPR) Survey of KIilbourne Hole, Southern New Mexico: Implication for Paleohydrology and Near Surface Geophysical Exploration of Mars and the Moon

    NASA Astrophysics Data System (ADS)

    Rhodes, N.; Hurtado, J. M.

    2013-05-01

    Features such as the Home Plate plateau on Mars, a suspected remnant of a phreatomagmatic eruption, can reveal important information about paleohydrologic conditions. The types and sizes of pyroclastic rocks produced by a phreatomagmatic eruption are indicative of the behavior of the explosion and the characteristics of the groundwater reservoir. Analysis of the pyroclast size distribution can be used to determine magma volatile content. We conduct an analysis of pyroclast size distribution using Ground Penetrating Radar (GPR) to make a quantitative estimate of the presence of past groundwater at Kilbourne Hole, a well-known phreatomagmatic crater located in southern Dona Ana County, New Mexico. As basaltic magma intruded the groundwater reservoir in the mid-Pleistocene, the water vaporized and caused a phreatomagmatic explosion that excavated the 2-km wide and 200-m deep depression. The pyroclastic units produced during a phreatomagmatic explosion are proportional to the size and the duration of the explosion and the size of the groundwater reservoir such that the wetter the eruption, the stronger the explosion. In a violent volcanic eruption, magma changes from a liquid into solid fragments and the explosion releases kinetic energy (Ek) by ejecting liquid water, vapor water (with mass Mw) and solid fragments (with mass Mf) at an ejection velocity (Ve). In order to determine Mw, we must know Ve. The relationship between Ve and the distance from center of the eruption (R) is such that Ve exponentially decreases with time (t) and R. A numerical model relating pyroclast size and Ve for material ejected in Hawaiian and Plinian eruptions shows that clast size also exponentially decreases with decreasing Ve. Based on these relationships, we use GPR to map the ejected clast size distribution as a function of distance from the edge of Kilbourne Hole in an effort to determine Ve and Mw. GPR surveys were performed in January 2012 and January 2013 using a Noggins 250 MHz

  6. Redesigning Curricula in Geology and Geophysics

    NASA Astrophysics Data System (ADS)

    Sparks, D. W.; Ewing, R. C.; Fowler, D.; Macik, M.; Marcantonio, F.; Miller, B.; Newman, J.; Olszewski, T.; Reece, R.; Rosser, S.

    2015-12-01

    In the summer of 2014, the Texas A&M Department of Geology and Geophysics partnered with the Texas A&M Center for Teaching Excellence to implement TAMU's curriculum revision process: a data-informed, faculty-driven, educational-developer-supported rebuilding of our degree programs and course offerings. The current curricula (B.S. and B.A. in Geology, B.S. in Geophysics) were put into place in 1997, following the merger of two separate departments. The needs and capabilities of the Department and the student body have changed significantly since that time: more than 50% turnover of the faculty, a rapidly-changing job climate for geologists and geophysicists, and a nearly five-fold increase in the undergraduate population to over 500 majors in Fall 2015. Surveys of former students, employers and faculty at other universities revealed more reasons to address the curriculum. Some of the most desired skills are also those at which our graduates feel and are perceived to be least prepared: oral communication and the ability to learn software packages (skills that are most challenging to teach with growing class sizes). The challenge facing the Department is to accommodate growing student numbers while maintaining strength in traditional instructor-intensive activities such as microscopy and field mapping, and also improving our graduates' non-geological skills (e.g., communication, software use, teamwork, problem-solving) to insulate them from volatility in the current job market. We formed the Curriculum Study Group, consisting of faculty, graduate students, advisors and curriculum experts, to gather and analyze data and define the knowledge and skill base a graduate of our department must have. In addition to conducting external surveys, this group interviewed current students and faculty to determine the strengths and weaknesses of our program. We developed program learning goals that were further specified into over fifty criteria. For each criteria we defined

  7. Terrestrial Planet Geophysics

    NASA Astrophysics Data System (ADS)

    Phillips, R. J.

    2008-12-01

    Terrestrial planet geophysics beyond our home sphere had its start arguably in the early 1960s, with Keith Runcorn contending that the second-degree shape of the Moon is due to convection and Mariner 2 flying past Venus and detecting no planetary magnetic field. Within a decade, in situ surface geophysical measurements were carried out on the Moon with the Apollo program, portions of the lunar magnetic and gravity fields were mapped, and Jack Lorell and his colleagues at JPL were producing spherical harmonic gravity field models for Mars using tracking data from Mariner 9, the first spacecraft to orbit another planet. Moreover, Mariner 10 discovered a planetary magnetic field at Mercury, and a young Sean Solomon was using geological evidence of surface contraction to constrain the thermal evolution of the innermost planet. In situ geophysical experiments (such as seismic networks) were essentially never carried out after Apollo, although they were sometimes planned just beyond the believability horizon in planetary mission queues. Over the last three decades, the discipline of terrestrial planet geophysics has matured, making the most out of orbital magnetic and gravity field data, altimetric measurements of surface topography, and the integration of geochemical information. Powerful constraints are provided by tectonic and volcanic information gleaned from surface images, and the engagement of geologists in geophysical exercises is actually quite useful. Accompanying these endeavors, modeling techniques, largely adopted from the Earth Science community, have become increasingly sophisticated and have been greatly enhanced by the dramatic increase in computing power over the last two decades. The future looks bright with exciting new data sets emerging from the MESSENGER mission to Mercury, the promise of the GRAIL gravity mission to the Moon, and the re-emergence of Venus as a worthy target for exploration. Who knows? With the unflagging optimism and persistence

  8. Integration of historical aerial and satellite photos, recent satellite images and geophysical surveys for the knowledge of the ancient Dyrrachium (Durres, Albania)

    NASA Astrophysics Data System (ADS)

    Malfitana, Daniele; Shehi, Eduard; Masini, Nicola; Scardozzi, Giuseppe

    2010-05-01

    The paper presents the preliminary results of an integrated multidiscipliary research project concerning the urban area of the modern Durres (ancient Dyrrachium). Here a joint Italian and Albanian researcher are starting preliminary investigations on the place of an ancient roman villa placed in the urban centre of the modern town. In a initial phase are offering interesting results the use of a rich multitemporal remote sensing data-set, historical aerial photos of 1920s and 1930s, photos of USA spy satellites of 1960s and 1970s (Corona KH-4A and KH-4B), and very high resolution satellite imagery. The historical aerial documentation is very rich and includes aerial photogrammetrich flights of two Italian Institutions: the private company SARA - Società Anonima Rilevamenti Aerofotogrammetrici in Rome (1928) and the IGM - Istituto Geografico Militare (1936, 1937 e 1941), which flew on Durres for purposes of cartographic production and military. These photos offer an image of the city before the urban expansion after the Second World War and in recent decades, progressively documented by satellite images of the 1960s-1970s and recent years. They enable a reconstruction of the ancient topography of the urban area, even with the possibility of detailed analysis, as in the case of the the Roman villa, nowadays buried under a modern garden, but also investigated with a GPR survey, in order to rebuild its plan and contextualize the villa in relation to the urban area of the ancient Dyrrachium.

  9. High-resolution geophysical data collected within Red Brook Harbor, Buzzards Bay, Massachusetts, in 2009

    USGS Publications Warehouse

    Turecek, Aaron M.; Danforth, William W.; Baldwin, Wayne E.; Barnhardt, Walter A.

    2012-01-01

    The U.S. Geological Survey conducted a high-resolution geophysical survey within Red Brook Harbor, Massachusetts, from September 28 through November 17, 2009. Red Brook Harbor is located on the eastern edge of Buzzards Bay, south of the Cape Cod Canal. The survey area was approximately 7 square kilometers, with depths ranging from 0 to approximately 10 meters. Data were collected aboard the U.S. Geological Survey Research Vessel Rafael. The research vessel was equipped with a 234-kilohertz interferometric sonar system to collect bathymetry and backscatter data, a dual frequency (3.5- and 200-kilohertz) compression high-intensity radar pulse seismic reflection profiler to collect subbottom data, a sound velocity profiler to acquire speed of sound within the water column, and a sea floor sampling device to collect sediment samples, video, and photographs. The survey was part of an ongoing cooperative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to map the geology of the Massachusetts inner continental shelf. In addition to inclusion within the cooperative geologic mapping effort, these data will be used to assess the shallow-water mapping capability of the geophysical systems deployed for this project, with an emphasis on identifying resolution benchmarks for the interferometric sonar system.

  10. 78 FR 57877 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ....S. Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical Data Preservation Program (NGGDPP) Advisory Committee AGENCY: U.S. Geological Survey....-5 p.m. Mountain Standard Time. The Advisory Committee, comprising representatives from...

  11. Asteroid Surface Geophysics

    NASA Astrophysics Data System (ADS)

    Murdoch, N.; Sánchez, P.; Schwartz, S. R.; Miyamoto, H.

    The regolith-covered surfaces of asteroids preserve records of geophysical processes that have occurred both at their surfaces and sometimes also in their interiors. As a result of the unique microgravity environment that these bodies possess, a complex and varied geophysics has given birth to fascinating features that we are just now beginning to understand. The processes that formed such features were first hypothesized through detailed spacecraft observations and have been further studied using theoretical, numerical, and experimental methods that often combine several scientific disciplines. These multiple approaches are now merging toward a further understanding of the geophysical states of the surfaces of asteroids. In this chapter we provide a concise summary of what the scientific community has learned so far about the surfaces of these small planetary bodies and the processes that have shaped them. We also discuss the state of the art in terms of experimental techniques and numerical simulations that are currently being used to investigate regolith processes occurring on small-body surfaces and that are contributing to the interpretation of observations and the design of future space missions.

  12. A German Geophysics School Project First steps to bring geophysical topics to schoolclasses

    NASA Astrophysics Data System (ADS)

    Schneider, S.

    2002-12-01

    In Germany Geophysics is a science with almost none or a bad reputation. People do not know to distinguish between Geophysics, Geography and Geology. In order to change the public view on Geosciences, a,School Project Geophysics' is going to be created at the Institute of Meteorology and Geophysics, Johann Wolfgang Goethe University, Frankfurt, which will offer geophysical ideas, methodes and scientific results to schoolclasses. After researches like PISA or TIMSS (third international Math and Nature-Science test) new concepts in education will be required. Interdisciplinary tasks are demanded by national and international commissions.\\The,School Project Geophysics' will be created to bring geophysical themes and results of scientific research into schools. One Day- or one Week-Workshops will help to publish geophysical contents in close cooperation with Physics - and Geography - teachers.\\Hands-on experiments (for advanced pupils) like refraction-Seismics or Magnetic measurements will lead students closer to scientific work and will help to establish personal interests in Earthsciences. Working with personally produced datasets will show the basics of inversion theory and point out the difficulties in creating models. Boundaries of data interpretation (the plurality of variables needed) will teach the school children to see scientific and statistic predictions and declarations more criticaly. Animations and Videos will present global examples (for example of volcanoes or Earthquakes) and lead over to regional sites. Excursions to these sites will help to show fieldwork methods and its problems and will convince to take a different look on topography and landscapes.\\All necessary utilities (Animations, Videos, Pictures and foils) will be offered to teachers in an online-data base which will be installed and managed by the project. Teachers and pupils might get easily into contact with Scientists to discuss geoscientific items. Further on extensions to geographic

  13. An integrated surface-geophysical investigation of the University of Connecticut landfill, Storrs, Connecticut, 2000

    USGS Publications Warehouse

    Johnson, Carole D.; Dawson, C.B.; Belaval, Marcel; Lane, Jr., John W.

    2002-01-01

    A surface-geophysical investigation to characterize the hydrogeology and contaminant distribution of the former landfill area at the University of Connecticut in Storrs, Connecticut, was conducted in 2000 to supplement the preliminary hydrogeologic assessment of the contamination of soil, surface water, and ground water at the site. A geophysical-toolbox approach was used to characterize the hydrogeology and contaminant distribution of the former landfill. Two-dimensional direct-current resistivity, inductive terrain-conductivity, and seismic-refraction surface-geophysical data were collected and interpreted in an iterative manner with exploratory drilling, borehole geophysics, and hydraulic testing. In this investigation, a geophysical-toolbox approach was used to 1) further define previously identified conductive anomalies and leachate plumes; 2) identify additional leachate plumes, possible fracture zones, and (or) conductive lithologic layers in the bedrock; and 3) delineate bedrock-surface topography in the drainage valleys north and south of the landfill. Resistivity and terrain-conductivity surveys were used to further delineate previously identified geophysical anomalies to the north and southwest of the landfill. A conductive anomaly identified in the terrain-conductivity survey to the north of the landfill in 2000 had a similar location and magnitude as an anomaly identified in terrain-conductivity surveys conducted in 1998 and 1999. Collectively, these surveys indicated that the magnitude of the conductive anomaly decreased with depth and with distance from the landfill. These anomalies indicated landfill leachate in the overburden and shallow bedrock. Results of previous surface-geophysical investigations southwest of the landfill indicated a shallow conductive anomaly in the overburden that extended into the fractured-bedrock aquifer. This conductive anomaly had a sheet-like geometry that had a north-south strike, dipped to the west, and terminated

  14. Geophysical characterization of Hydrogeological processes at the catchment scale

    NASA Astrophysics Data System (ADS)

    Flores Orozco, Adrian; Gallistl, Jakob; Schlögel, Ingrid; Chwatal, Werner; Oismüller, Markus; Blöschl, Günter

    2016-04-01

    The characterization of hydrogeological properties in the subsurface with high resolution across space and time scales is critical to improve our understanding of water flow and transport processes. However, to date, hydrogeological investigations are mainly performed through well-tests or the analysis of samples, thus, limiting the spatial resolution of the investigation. To properly capture heterogeneities in the subsurface controlling surface-groundwater interactions, modern hydrogeological studies require the development of innovative investigation techniques that permit to gain continuous information about subsurface state with high spatial and temporal resolution at different scales: from the pore-space all the way to the catchment. To achieve this, we propose the conduction of geophysical surveys, in particular field-scale Spectral Induced Polarization (SIP) imaging measurements. SIP images provide information about the complex electrical conductivity (CEC), which is controlled by important hydrogeological parameters, such as porosity, water content and the chemical properties of the pore-water. Here, we present imaging results collected at the catchment scale (approximately 66 ha), which permitted to gain detailed information about the spatial variability of hydrogeological parameters at different scales. The heterogeneities observed in the geophysical images revealed consistency with independent information collected at the study area. In addition to this, and taking into account that different geophysical methods yield information about different properties and at diverse scales, interpretation of the SIP images was improved by incorporation of complementary measurements, such as: ElectroMagnetic Induction (EMI), Ground Penetrating Radar (GPR), Multichannel Analysis of Surface-Waves (MASW) and Seismic Refraction-Reflection (SRR).

  15. Proposed geologic model based on geophysical well logs

    SciTech Connect

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

    1981-01-01

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

  16. High-resolution geophysical data from the inner continental shelf—Buzzards Bay, Massachusetts

    USGS Publications Warehouse

    Ackerman, Seth D.; Andrews, Brian D.; Foster, David S.; Baldwin, Wayne E.; Schwab, William C.

    2012-01-01

    The U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM) have cooperated to map approximately 410 square kilometers (km²) of the inner continental shelf in Buzzards Bay, Massachusetts. This report contains geophysical data collected by the USGS on three cruises conducted in 2009, 2010, and 2011, and additional bathymetry data collected by the National Oceanic and Atmospheric Administration in 2004. The geophysical data include (1) swath bathymetry using interferometric sonar and multibeam echosounder systems, (2) acoustic backscatter from sidescan sonar, and (3) seismic-reflection profiles from a chirp subbottom profiler. These spatial data support research on the Quaternary evolution of Buzzards Bay, the influence of sea-level change and sediment supply on coastal evolution, and efforts to understand the type, distribution, and quality of subtidal marine habitats in the coastal ocean of Massachusetts.

  17. National Geophysical Data Center Tsunami Data Archive

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  18. Geophysical mapping of solution and collapse sinkholes

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg

    2014-12-01

    Karst rocks such as limestone, dolomite, anhydrite, gypsum, or salt can be dissolved physically by water or chemically by water enriched with carbon dioxide. The dissolution is driven by water flowing through the karst aquifer and either occurs along fractures and bedding partings in telogenetic rocks, or within the primary interconnected pore space in eogenetic rocks. The enlargement of either fractures or pores by dissolution creates a large secondary porosity typical of soluble rocks, which is often very heterogenously distributed and results in preferential flow paths in the sub-surface, with cavities as large-scale end members of the sub-surface voids. Once the sub-surface voids enlarged by dissolution grow to a certain size, the overburden rock can become unstable and voids and caves can collapse. Depending on the type of overburden, the collapse initiated at depth may propagate towards the surface and finally results at the surface as collapse sinkholes and tiangkengs on the very large scale. We present results from geophysical surveys over existing karst structures based on gravimetric, electrical, and geomagnetical methods. We have chosen two types of sinkholes, solution and collapse sinkholes, to capture and compare the geophysical signals resulting from these karst structures. We compare and discuss our geophysical survey results with simplified theoretical models describing the evolution of the karst structure, and we derive three-dimensional structural models of the current situation for the different locations with our numerical tool PREDICTOR.

  19. Goddard Geophysical and Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Figueroa, Ricardo

    2013-01-01

    This report summarizes the technical parameters and the technical staff of the VLBI system at the fundamental station GGAO. It also gives an overview about the VLBI activities during the report year. The Goddard Geophysical and Astronomical Observatory (GGAO) consists of a 5-meter radio telescope for VLBI, a new 12-meter radio telescope for VLBI2010 development, a 1-meter reference antenna for microwave holography development, an SLR site that includes MOBLAS-7, the NGSLR development system, and a 48" telescope for developmental two-color Satellite Laser Ranging, a GPS timing and development lab, a DORIS system, meteorological sensors, and a hydrogen maser. In addition, we are a fiducial IGS site with several IGS/IGSX receivers. GGAO is located on the east coast of the United States in Maryland. It is approximately 15 miles NNE of Washington, D.C. in Greenbelt, Maryland.

  20. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    NASA Astrophysics Data System (ADS)

    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

  1. Integrated, flexible, and rapid geophysical surveying

    NASA Astrophysics Data System (ADS)

    Miller, S. F.; McGinnis, L. D.; Thompson, M. D.; Tome, C.

    Aberdeen Proving Ground (APG) is currently managing a comprehensive Installation Restoration Program involving more than 360 solid-waste managing units contained within 13 study areas. The Edgewood area and two landfills in the Aberdeen area appear on the National Priority List under the Comprehensive Environmental Response, Compensation, and Liability Act. Therefore, APG has entered into an interagency agreement with the US Environmental Protection Agency to address the listed areas. The West Branch of the Canal Creek area, located within the Edgewood area, is one of the areas that requires a Source Definition Study because there is an ongoing release of volatile organic compounds into the creek. A report prepared in 1989 included a list of 29 potentially contaminated buildings in the Edgewood area. Sixteen of the buildings contain known contaminants, nine buildings contain unknown contaminants, and four of the buildings are potentially clean. The EAI report recommended that a sampling and monitoring program be established to verify contamination levels in and around each building. Thirteen of the potentially contaminated buildings are in the West Branch of the Canal Creek area and are potential sources of volatile organic compounds. Operations have ceased, and the buildings have been abandoned, but processing equipment, sumps, drains, ventilation systems, and underground storage tanks remain. These appurtenances may contain liquid, solid, or vapor contaminants of unknown nature.

  2. Integrated, flexible, and rapid geophysical surveying

    SciTech Connect

    Miller, S.F.; McGinnis, L.D.; Thompson, M.D.; Tome, C.

    1993-01-01

    Aberdeen Proving Ground (APG), in the state of Maryland (Figure 1), is currently managing a comprehensive Installation Restoration Program involving more than 360 solid-waste managing units contained within 13 study areas. The Edgewood area and two landfills in the Aberdeen area appear on the National Priority List under the Comprehensive Environmental Response, Compensation, and Liability Act. Therefore, APG has entered into an interagency agreement with the US Environmental Protection Agency to address the listed areas. The West Branch of the Canal Creek area (Figure 1), located within the Edgewood area, is one of the areas that requires a Source Definition Study because there is an ongoing release of volatile organic compounds into the creek. A report prepared by EAI Corporation (1989) included a list of 29 potentially contaminated buildings in the Edgewood area. Sixteen of the buildings contain known contaminants, nine buildings contain unknown contaminants, and four of the buildings are potentially clean. The EAI report recommended that a sampling and monitoring program be established to verify contamination levels in and around each building. Thirteen of the potentially contaminated buildings are in the West Branch of the Canal Creek area and are potential sources of volatile organic compounds. Operations have ceased and the buildings have been abandoned, but processing equipment, sumps, drains, ventilation systems, and underground storage tanks remain. These appurtenances may contain liquid, solid, or vapor contaminants of unknown nature.

  3. Integrated, flexible, and rapid geophysical surveying

    SciTech Connect

    Miller, S.F.; McGinnis, L.D.; Thompson, M.D.; Tome, C.

    1993-03-01

    Aberdeen Proving Ground (APG), in the state of Maryland (Figure 1), is currently managing a comprehensive Installation Restoration Program involving more than 360 solid-waste managing units contained within 13 study areas. The Edgewood area and two landfills in the Aberdeen area appear on the National Priority List under the Comprehensive Environmental Response, Compensation, and Liability Act. Therefore, APG has entered into an interagency agreement with the US Environmental Protection Agency to address the listed areas. The West Branch of the Canal Creek area (Figure 1), located within the Edgewood area, is one of the areas that requires a Source Definition Study because there is an ongoing release of volatile organic compounds into the creek. A report prepared by EAI Corporation (1989) included a list of 29 potentially contaminated buildings in the Edgewood area. Sixteen of the buildings contain known contaminants, nine buildings contain unknown contaminants, and four of the buildings are potentially clean. The EAI report recommended that a sampling and monitoring program be established to verify contamination levels in and around each building. Thirteen of the potentially contaminated buildings are in the West Branch of the Canal Creek area and are potential sources of volatile organic compounds. Operations have ceased and the buildings have been abandoned, but processing equipment, sumps, drains, ventilation systems, and underground storage tanks remain. These appurtenances may contain liquid, solid, or vapor contaminants of unknown nature.

  4. Geophysical study of the Building 103 Dump, Aberdeen Proving Ground

    SciTech Connect

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

    1992-12-01

    The Building 103 Dump is one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, resistivity, ground-penetrating radar, and seismic refraction, were conducted. These surveys indicate that much of the area is free of debris. However, prominent magnetic and resistivity anomalies occur along well-defined lineaments, suggestive of a dendritic stream pattern. Prior to the onset of dumping, the site was described as a ``sand pit,`` which suggests that headward erosion of Canal Creek tributaries cut into the surficial aquifer. Contaminants dumped into the landfill would have direct access to the surficial aquifer and thus to Canal Creek. Seismic refraction profiling indicates 6--12 ft of fill material now rests on the former land surface. Only the northern third of the former landfill was geophysically surveyed.

  5. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  6. Geophysical Technologies to Image Old Mine Works

    SciTech Connect

    Kanaan Hanna; Jim Pfeiffer

    2007-01-15

    ZapataEngineering, Blackhawk Division performed geophysical void detection demonstrations for the US Department of Labor Mine Safety and Health Administration (MSHA). The objective was to advance current state-of-practices of geophysical technologies for detecting underground mine voids. The presence of old mine works above, adjacent, or below an active mine presents major health and safety hazards to miners who have inadvertently cut into locations with such features. In addition, the presence of abandoned mines or voids beneath roadways and highway structures may greatly impact the performance of the transportation infrastructure in terms of cost and public safety. Roads constructed over abandoned mines are subject to potential differential settlement, subsidence, sinkholes, and/or catastrophic collapse. Thus, there is a need to utilize geophysical imaging technologies to accurately locate old mine works. Several surface and borehole geophysical imaging methods and mapping techniques were employed at a known abandoned coal mine in eastern Illinois to investigate which method best map the location and extent of old works. These methods included: 1) high-resolution seismic (HRS) using compressional P-wave (HRPW) and S-wave (HRSW) reflection collected with 3-D techniques; 2) crosshole seismic tomography (XHT); 3) guided waves; 4) reverse vertical seismic profiling (RVSP); and 5) borehole sonar mapping. In addition, several exploration borings were drilled to confirm the presence of the imaged mine voids. The results indicated that the RVSP is the most viable method to accurately detect the subsurface voids with horizontal accuracy of two to five feet. This method was then applied at several other locations in Colorado with various topographic, geologic, and cultural settings for the same purpose. This paper presents the significant results obtained from the geophysical investigations in Illinois.

  7. Borehole Geophysical Logging Program: Incorporating New and Existing Techniques in Hydrologic Studies

    USGS Publications Warehouse

    Wacker, Michael A.; Cunningham, Kevin J.

    2008-01-01

    The borehole geophysical logging program at the U.S. Geological Survey (USGS)-Florida Integrated Science Center (FISC) provides subsurface information needed to resolve geologic, hydrologic, and environmental issues in Florida. The program includes the acquisition, processing, display, interpretation, and archiving of borehole geophysical logs. The borehole geophysical logging program is a critical component of many FISC investigations, including hydrogeologic framework studies, aquifer flow-zone characterization, and freshwater-saltwater interface delineation.

  8. Detailed Geophysical Fault Characterization in Yucca Flat, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Asch, Theodore H.; Sweetkind, Donald S.; Burton, Bethany L.; Wallin, Erin L.

    2009-01-01

    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site (NTS) in Nye County, Nevada. Between the years 1951 and 1992, 659 underground nuclear tests took place in Yucca Flat; most were conducted in large, vertical excavations that penetrated alluvium and the underlying Cenozoic volcanic rocks. Radioactive and other potential chemical contaminants at the NTS are the subject of a long-term program of investigation and remediation by the U.S. Department of Energy (DOE), National Nuclear Security Administration, Nevada Site Office, under its Environmental Restoration Program. As part of the program, the DOE seeks to assess the extent of contamination and to evaluate the potential risks to humans and the environment from byproducts of weapons testing. To accomplish this objective, the DOE Environmental Restoration Program is constructing and calibrating a ground-water flow model to predict hydrologic flow in Yucca Flat as part of an effort to quantify the subsurface hydrology of the Nevada Test Site. A necessary part of calibrating and evaluating a model of the flow system is an understanding of the location and characteristics of faults that may influence ground-water flow. In addition, knowledge of fault-zone architecture and physical properties is a fundamental component of the containment of the contamination from underground nuclear tests, should such testing ever resume at the Nevada Test Site. The goal of the present investigation is to develop a detailed understanding of the geometry and physical properties of fault zones in Yucca Flat. This study was designed to investigate faults in greater detail and to characterize fault geometry, the presence of fault splays, and the fault-zone width. Integrated geological and geophysical studies have been designed and implemented to work toward this goal. This report describes the geophysical surveys conducted near two drill holes in Yucca Flat, the data analyses performed, and the

  9. Detailed Geophysical Fault Characterization in Yucca Flat, Nevada Test Site, Nevada

    SciTech Connect

    Theodore H. Asch; Donald Sweetkind; Bethany L. Burton; Erin L. Wallin

    2009-02-10

    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site (NTS) in Nye County, Nevada. Between the years 1951 and 1992, 659 underground nuclear tests took place in Yucca Flat; most were conducted in large, vertical excavations that penetrated alluvium and the underlying Cenozoic volcanic rocks. Radioactive and other potential chemical contaminants at the NTS are the subject of a long-term program of investigation and remediation by the U.S. Department of Energy (DOE), National Nuclear Security Administration, Nevada Site Office, under its Environmental Restoration Program. As part of the program, the DOE seeks to assess the extent of contamination and to evaluate the potential risks to humans and the environment from byproducts of weapons testing. To accomplish this objective, the DOE Environmental Restoration Program is constructing and calibrating a ground-water flow model to predict hydrologic flow in Yucca Flat as part of an effort to quantify the subsurface hydrology of the Nevada Test Site. A necessary part of calibrating and evaluating a model of the flow system is an understanding of the location and characteristics of faults that may influence ground-water flow. In addition, knowledge of fault-zone architecture and physical properties is a fundamental component of the containment of the contamination from underground nuclear tests, should such testing ever resume at the Nevada Test Site. The goal of the present investigation is to develop a detailed understanding of the geometry and physical properties of fault zones in Yucca Flat. This study was designed to investigate faults in greater detail and to characterize fault geometry, the presence of fault splays, and the fault-zone width. Integrated geological and geophysical studies have been designed and implemented to work toward this goal. This report describes the geophysical surveys conducted near two drill holes in Yucca Flat, the data analyses performed, and the

  10. Geophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Busse, F. H.

    In the past 8 years, since Pedlosky's book was first published, it has found a well established place in the literature of dynamical meteorology and physical oceanography. Geophysicists less familiar with these fields may need to be reminded that the subject of geophysical fluid dynamics, in the narrow definition used in the title of the book, refers to the theory of the large-scale motions of the atmosphere and the oceans. Topics such as thermal convection in the atmosphere or in Earth's mantle and core are not treated in this book, and the reader will search in vain for a discussion of atmospheric or oceanic tides. The theory of quasi-geostrophic flow is described comprehensively, however, and its major applications to problems of atmospheric and oceanic circulations are considered in detail.

  11. Sampling functions for geophysics

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  12. Geophysics of Mars

    NASA Technical Reports Server (NTRS)

    Wells, R. A.

    1979-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Eppelbaum, L. V.

    2009-04-01

    localization of archaeological targets: An introduction. Geoinformatics, 11, No.1, 19-28. Eppelbaum, L.V., 2005. Multilevel observations of magnetic field at archaeological sites as additional interpreting tool. Proceed. of the 6th Conference of Archaeological Prospection, Roma, Italy, 4 pp. Eppelbaum, L.V., 2007a. Localization of Ring Structures in Earth's Environments. Proceed. of the 7th Conference of Archaeological Prospection. Nitra, Slovakia, 145-148. Eppelbaum, L.V., 2007b. Revealing of subterranean karst using modern analysis of potential and quasi-potential fields. Proceed. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems, Denver, USA, 797-810. Eppelbaum, L.V., 2008a. Remote operated vehicle geophysical survey using magnetic and VLF methods: proposed schemes for data processing and interpretation. Proceed. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems, Philadelphia, USA, 938-963. Eppelbaum, L.V., 2008b. On the application of near-surface temperature investigations for delineation of archaeological targets. Trans. of the 1st International Workshop on Advances in Remote Sensing for Archaeology and Cultural Heritage Management, Rome, Italy, 179-183. Eppelbaum, L.V., 2009. Application of microgravity at archaeological sites in Israel: some estimation derived from 3D modeling and quantitative analysis of gravity field. Proceed. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems, Denver, USA, 10 pp. Eppelbaum, L. and Ben-Avraham, Z., 2002. On the development of 4D geophysical Data Base of archaeological sites in Israel. Trans. of the Conf. of the Israel Geol. Soc. Ann. Meet., MaHagan - Lake Kinneret, Israel, p.21. Eppelbaum, L., Ben-Avraham, Z., and Itkis, S., 2003a. Ancient Roman Remains in Israel provide a challenge for physical-archaeological modeling techniques. First Break, 21 (2), 51-61. Eppelbaum, L.V., Ben-Avraham, Z., and Itkis, S.E., 2003b

  14. Applications of geophysical methods to volcano monitoring

    USGS Publications Warehouse

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

    2006-01-01

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

  15. Airborne Gravity Survey and Ground Gravity in Afghanistan: A Website for Distribution of Data

    USGS Publications Warehouse

    Abraham, Jared D.; Anderson, Eric D.; Drenth, Benjamin J.; Finn, Carol A.; Kucks, Robert P.; Lindsay, Charles R.; Phillips, Jeffrey D.; Sweeney, Ronald E.

    2008-01-01

    Afghanistan?s geologic setting suggests significant natural resource potential. Although important mineral deposits and petroleum resources have been identified, much of the country?s potential remains unknown. Airborne geophysical surveys are a well- accepted and cost-effective method for remotely obtaining information of the geological setting of an area. A regional airborne geophysical survey was proposed due to the security situation and the large areas of Afghanistan that have not been covered using geophysical exploration methods. Acting upon the request of the Islamic Republic of Afghanistan Ministry of Mines, the U.S. Geological Survey contracted with the U.S. Naval Research Laboratory to jointly conduct an airborne geophysical and remote sensing survey of Afghanistan. Data collected during this survey will provide basic information for mineral and petroleum exploration studies that are important for the economic development of Afghanistan. Additionally, use of these data is broadly applicable in the assessment of water resources and natural hazards, the inventory and planning of civil infrastructure and agricultural resources, and the construction of detailed maps. The U.S. Geological Survey is currently working in cooperation with the U.S. Agency of International Development to conduct resource assessments of the country of Afghanistan for mineral, energy, coal, and water resources, and to assess geologic hazards. These geophysical and remote sensing data will be used directly in the resource and hazard assessments.

  16. Geophysical investigation at Philadelphia Naval Shipyard. Final report,

    SciTech Connect

    Sharp, M.K.

    1992-03-01

    Results of a geophysical investigation at the incinerator site of Philadelphia Naval Shipyard are presented. Following the end of World War II, 50 to 60 pallets of gas cylinders were reportedly buried to the west of the old incinerator at Girard Point. The contents of the cylinders are unknown. Extensive filling operations occurred at Girard Point from 1940 to 1970, resulting in shallow groundwater surface in the area, 2 to 10 ft deep, which would indicate that the cylinders are probably in direct contact with the water surface. The geophysical investigation presented in this report was designed to help alleviate uncertainties produced from previous studies in the area. The geophysical program included electromagnetic induction and magnetic survey methods. The results of the various surveys were integrated, and numerous anomalous areas were interpreted. Anomalies warranting further investigation were presented along with a priority ranking.

  17. Assessing the Value of Additional Years of Schooling for the Non-Academically Inclined. Longitudinal Surveys of Australian Youth. Research Report 38

    ERIC Educational Resources Information Center

    Dockery, Alfred Michael

    2005-01-01

    In this report data from the 1995 Year 9 Cohort of the Longitudinal Surveys of Australian Youth (LSAY) is used along with a variety of empirical approaches to assess the benefits of additional years of schooling for various groups of youth conditional upon their estimated propensity to engage in further schooling. Background material is provided…

  18. Geophysical Investigation of Oldoinyo Lengai

    NASA Astrophysics Data System (ADS)

    Scheiber, S. E.; Webb, S. J.; Dirks, P. H.

    2006-12-01

    Oldoinyo Lengai, which means "Mountain of God" in Maasai, is a 2886 m high stratovolcano situated in Northern Tanzania, next to one of the large fault scarps that defines the western edge of the East African Rift Valley. Lengai is the only volcano in the world that erupts natrocarbonatite lava and has been in a state of near-eruption since 1983. A large amount of work has been done in terms of the geology and petrology of this unique volcano, but very little has been done in terms of geophysics. A research team from the University of the Witwatersrand, South Africa will be conducting a gravity and differential GPS survey on Lengai during December 2006 and January 2007. Seismic monitoring of the volcano will also take place for the duration of the survey using vertical 1 Hz geophones. A gravity profile collected over the volcano by the British Schools Exploring Society in 2004 shows a negative anomaly of approximately 185 mGals. This is after a terrain correction is applied to the data using 1:50000 digitized maps and a vertical prism formula. A single seismometer, with a frequency of 1Hz and then 0.033 Hz, was set up on the volcano in 2001 and 2002 by a graduate student from the University of Washington. A few local volcanotectonic (VT) events were recorded; however the research team was unable to conclude whether the events were from Lengai or the nearby rift. A sustained non-harmonic tremor signal with a fairly broad spectral peak was also observed, but no very long-period (VLP) signals. The gravity and DGPS data collected during the 2006/2007 survey will be processed and used as a baseline for future measurements on the volcano. The data will also be modeled in an attempt to determine the size and position of the magma chamber. These gravity data will be compared with the profile collected in 2004 in an attempt to see whether there have been any large subsurface mass changes over the past two years, or the extent of weathering. Recorded seismicity will be used

  19. Contribution of Geophysical Prospecting to Geohazard Evaluation

    SciTech Connect

    Nicolich, Rinaldo

    2006-03-23

    The physical properties of the subsoil are studied using geophysical methods. These studies are always indirect, such as gravimetric, magnetometric, magnetotelluric or reflection-refraction seismic surveys and are often combined to obtain more accurate and reliable results. With these tools the oil industry commonly investigates the sedimentary basins to localize structures that may favor the accumulation of hydrocarbons. Above all, seismic prospecting allow the understanding of the underground geology, defining boundaries of the geological formations as well as mechanical and physical properties of the rocks. New cutting-edge techniques allow high quality data to be obtained in almost all geological contexts and make reflection seismic the most powerful tool in subsurface observations. The seismic method was utilized in geothermal resources investigation, research of water strategic resources, volcanic risks assessment, etc. The refraction method was the first to be used in the exploration of oil reservoirs. At present the industry employs mainly refraction seismics to study shallow formations. Conversely, university researchers have applied wide-angle reflection-refraction surveys to localize deep crustal interfaces analyzing the high amplitudes of the wide-angle reflections and the velocities obtained from the refracted signals. Moho discontinuity and velocity distribution within the crust were mapped out, indicating thickness and boundary conditions in different geological settings. The maps have been used in the analysis of geodynamical behavior and of active movements within the crust, useful for seismotectonic investigations. The further addition of the seismic reflection imaging, with deep penetration and long transects, completed multidisciplinary programs to unravel the structure of the crust with clear seismic images and models. High-resolution application of seismic has a central role in the identification and characterization of seismotectonic and

  20. Temporal Geophysical Signatures Due to Contaminant Mass Remediation

    EPA Science Inventory

    Geophysical surveys acquired over a ten year period are used to document changes in bulk electrical conductivity associated with the attenuation of hydrocarbon contaminants at the former fire training facility (FT-02) Wurtsmith Air Force base (WAFB), Oscoda, MI, USA. Initial inv...

  1. Jesuit Geophysical Observatories

    NASA Astrophysics Data System (ADS)

    Udias, Agustin; Stauder, William

    Jesuits have had ah interest in observing and explaining geophysical phenomena since this religious order, the Society of Jesus, was founded by Ignatius of Loyola in 1540. Three principal factors contributed to this interest: their educational work in colleges and universities, their missionary endeavors to remote lands where they observed interesting and often as yet undocumented natural phenomena, and a network of communication that brought research of other Jesuits readily to their awareness.One of the first and most important Jesuit colleges was the Roman College (today the Gregorian University) founded in 1551 in Rome, which served as a model for many other universities throughout the world. By 1572, Christopher Clavius (1537-1612), professor of mathematics at the Roman College, had already initiated an important tradition of Jesuit research by emphasizing applied mathematics and insisting on the need of serious study of mathematics in the program of studies in the humanities. In 1547 he directed a publication of Euclid's work with commentaries, and published several treatises on mathematics, including Arithmetica Practica [1585], Gnomonicae [1581], and Geometrica Practica [1606]. Clavius was also a Copernican and supported his friend Galileo when he announced the discovery of the satellites of Jupiter.

  2. A ``model`` geophysics program

    SciTech Connect

    Nyquist, J.E.

    1994-03-01

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

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

    SciTech Connect

    Mitchell, J.C.

    1981-12-01

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

  4. Geophysical applications for levee assessment

    NASA Astrophysics Data System (ADS)

    Chlaib, Hussein Khalefa

    Levees are important engineering structures that build along the rivers to protect the human lives and shield the communities as well as agriculture lands from the high water level events. Animal burrows, subsurface cavities, and low density (high permeability) zones are weakness features within the levee body that increase its risk of failure. To prevent such failure, continuous monitoring of the structure integrity and early detection of the weakness features must be conducted. Application of Ground Penetrating Radar (GPR) and Capacitively Coupled Resistivity (CCR) methods were found to be very effective in assessing the levees and detect zones of weakness within the levee body. GPR was implemented using multi-frequency antennas (200, 400, and 900 MHz) with survey cart/wheel and survey vehicle. The (CCR) method was applied by using a single transmitter and three receivers. Studying the capability and the effectiveness of these methods in levee monitoring, subsurface weakness feature detection, and studying the structure integrity of levees were the main tasks of this dissertation. A set of laboratory experiments was conducted at the Geophysics Laboratory of the University of Arkansas at Little Rock (UALR) to analyze the polarity change in GPR signals in the presence of subsurface voids and water-filled cavities. Also three full scale field expeditions at the Big Dam Bridge (BDB) Levee, Lollie Levee, and Helena Levee in Arkansas were conducted using the GPR technique. This technique was effective in detecting empty, water, and clay filled cavities as well as small scale animal burrows (small rodents). The geophysical work at BDB and Lollie Levees expressed intensive subsurface anomalies which might decrease their integrity while the Helena Levee shows less subsurface anomalies. The compaction of levee material is a key factor affecting piping phenomenon. The structural integrity of the levee partially depends on the density/compaction of the soil layers. A

  5. Integrating Geophysics, Geology, and Hydrology for Enhanced Hydrogeological Modeling

    NASA Astrophysics Data System (ADS)

    Auken, E.

    2012-12-01

    Geophysical measurements are important for providing information on the geological structure to hydrological models. Regional scale surveys, where several watersheds are mapped at the same time using helicopter borne transient electromagnetic, results in a geophysical model with a very high lateral and vertical resolution of the geological layers. However, there is a bottleneck when it comes to integrating the information from the geophysical models into the hydrological model. This transformation is difficult, because there is not a simple relationship between the hydraulic conductivity needed for the hydrological model and the electrical conductivity measured by the geophysics. In 2012 the Danish Council for Strategic Research has funded a large research project focusing on the problem of integrating geophysical models into hydrological models. The project involves a number of Danish research institutions, consulting companies, a water supply company, as well as foreign partners, USGS (USA), TNO (Holland) and CSIRO (Australia). In the project we will: 1. Use statistical methods to describe the spatial correlation between the geophysical and the lithological/hydrological data; 2. Develop semi-automatic or automatic methods for transforming spatially sampled geophysical data into geological- and/or groundwater-model parameter fields; 3. Develop an inversion method for large-scale geophysical surveys in which the model space is concordant with the hydrological model space 4. Demonstrate the benefits of spatially distributed geophysical data for informing and updating groundwater models and increasing the predictive power of management scenarios. 5. Develop a new receiver system for Magnetic Resonance Sounding data and further enhance the resolution capability of data from the SkyTEM system. 6. In test areas in Denmark, Holland, USA and Australia we will use data from existing airborne geophysical data, hydrological and geological data and also collect new airborne

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Inversion Algorithms for Geophysical Problems

    DTIC Science & Technology

    1987-12-16

    ktdud* Sccumy Oass/Kjoon) Inversion Algorithms for Geophysical Problems (U) 12. PERSONAL AUTHOR(S) Lanzano, Paolo 13 «. TYPE OF REPORT Final 13b...spectral density. 20. DISTRIBUTION/AVAILABILITY OF ABSTRACT 13 UNCLASSIFIED/UNLIMITED D SAME AS RPT n OTIC USERS 22a. NAME OF RESPONSIBLE...Research Laboratory ’^^ SSZ ’.Washington. DC 20375-5000 NRLrMemorandum Report-6138 Inversion Algorithms for Geophysical Problems p. LANZANO Space

  9. Marine Geophysics: a Navy Symposium

    DTIC Science & Technology

    1987-09-01

    post-docs are now the current leaders in marine geology and geophysics, not only in the United States but also in Britain, France, and Australia ...to make it fun both for themselves and for others was the keystone of the success of the marine geology and geophysics program at Scripps. They, with...G. G. Shor, Jr., R. W. Raitt, and M. Henry. 1977. Seismic refraction and reflection studies of crustal structure of the eastern Sunda and western

  10. Lake Ontario geological and geophysical data sources

    USGS Publications Warehouse

    Hutchinson, Deborah R.; Wold, Richard J.

    1979-01-01

    A bibliography of various geological and geophysical data sources was compiled as part of an overall effort to evaluate the status of research on the Great Lakes.  We hope that such a summary will be a catalyst for additional work and be an aid in planning future work.  Our presentation has two forms: maps showing the locations of the different data types and a bibliography which lists the references from the maps and additional relevant papers.  The charts shown in this map summarize the data source for Lake Ontario.

  11. Planetary Geophysics and Tectonics

    NASA Technical Reports Server (NTRS)

    Zuber, Maria

    2005-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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

  13. Applied high resolution geophysical methods: Offshore geoengineering hazards

    SciTech Connect

    Trabant, P.K.

    1984-01-01

    This book is an examination of the purpose, methodology, equipment, and data interpretation of high-resolution geophysical methods, which are used to assess geological and manmade engineering hazards at offshore construction locations. It is a state-of-the-art review. Contents: 1. Introduction. 2. Maring geophysics, an overview. 3. Marine geotechnique, an overview. 4. Echo sounders. 5. Side scan sonar. 6. Subbottom profilers. 7. Seismic sources. 8. Single-channel seismic reflection systems. 9. Multifold acquisition and digital processing. 10. Marine magnetometers. 11. Marine geoengineering hazards. 12. Survey organization, navigation, and future developments. Appendix. Glossary. References. Index.

  14. Geophysical logging and thermal imaging at the Hemphill Road TCE NPL Superfund site near Gastonia, North Carolina

    USGS Publications Warehouse

    Antolino, Dominick J.; Chapman, Melinda J.

    2017-01-01

    The collection of borehole geophysical logs and thermal imaging data was conducted by the U.S. Geological Survey South Atlantic Water Science Center in the vicinity of the Hemphill Road TCE National Priorities List Superfund site near Gastonia, North Carolina, during August 2014 through February 2015. In an effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants, surface geological mapping and borehole geophysical log and image data collection, which included the delineation of more than 600 subsurface features (primarily fracture orientations) was conducted in 5 open borehole wells and 2 private supply bedrock wells. In addition, areas of potential groundwater discharge within a down-gradient, nearby creek were determined using thermal imagery to calculate temperature differences between the stream and bank seepage.

  15. Geophysical logging and thermal imaging near the Hemphill Road TCE National Priorities List Superfund site near Gastonia, North Carolina

    USGS Publications Warehouse

    Antolino, Dominick J.; Chapman, Melinda J.

    2017-03-27

    Borehole geophysical logs and thermal imaging data were collected by the U.S. Geological Survey near the Hemphill Road TCE (trichloroethylene) National Priorities List Superfund site near Gastonia, North Carolina, during August 2014 through February 2015. In an effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants, surface geological mapping and borehole geophysical log and thermal imaging data collection, which included the delineation of more than 600 subsurface features (primarily fracture orientations), was completed in five open borehole wells and two private supply bedrock wells. In addition, areas of possible groundwater discharge within a nearby creek downgradient of the study site were determined based on temperature differences between the stream and bank seepage using thermal imagery.

  16. The National Geological and Geophysical Data Preservation Program

    NASA Astrophysics Data System (ADS)

    Dickinson, T. L.; Steinmetz, J. C.; Gundersen, L. C.; Pierce, B. S.

    2006-12-01

    The ability to preserve and maintain geoscience data and collections has not kept pace with the growing need for accessible digital information and the technology to make it so. The Nation has lost valuable and unique geologic records and is in danger of losing much more. Many federal and state geological repositories are currently at their capacity for maintaining and storing data or samples. Some repositories are gaining additional, but temporary and substandard space, using transport containers or offsite warehouses where access is limited and storage conditions are poor. Over the past several years, there has been an increasing focus on the state of scientific collections in the United States. For example, the National Geological and Geophysical Data Preservation Program (NGGDPP) Act was passed as part of the Energy Policy Act of 2005, authorizing $30 million in funding for each of five years. The Act directs the U.S. Geological Survey to administer this program that includes a National Digital Catalog and Federal assistance to support our nation's repositories. Implementation of the Program awaits federal appropriations. The NGGDPP is envisioned as a national network of cooperating geoscience materials and data repositories that are operated independently yet guided by unified standards, procedures, and protocols for metadata. The holdings will be widely accessible through a common and mirrored Internet-based catalog (National Digital Catalog). The National Digital Catalog will tie the observations and analyses to the physical materials they come from. Our Nation's geological and geophysical data are invaluable and in some instances irreplaceable due to the destruction of outcrops, urbanization and restricted access. These data will enable the next generation of scientific research and education, enable more effective and efficient research, and may have future economic benefits through the discovery of new oil and gas accumulations, and mineral deposits.

  17. Visualization techniques and tools for large geo-physical networks

    NASA Astrophysics Data System (ADS)

    Nocke, Thomas; Buschmann, Stefan; Donges, Jonathan F.; Marwan, Norbert

    2016-04-01

    Network analysis is an important approach in studying complex phenomena within geophysical observation and simulation data. This field produces increasing numbers of large geo-referenced networks to be analyzed. Particular focus lies on the network analysis of the complex statistical interrelationship structure within climatological fields. The typical procedure for such network analyzes is the extraction of network measures in combination with static standard visualization methods. To analyze the visualization challenges within this field, we performed a questionnaire with climate and complex system scientists, and identified a strong requirement for solutions visualizing large and very large geo-referenced networks by providing alternative mappings for static plots and allowing for interactive visualization for networks with 100.000 or even millions of edges. In addition, the questionnaire revealed, that existing interactive visualization methods and tools for geo-referenced network exploration are often either not known to the analyst or their potential is not fully exploited. Within this presentation, we illustrate how interactive visual analytics methods in combination with geo-visualisation can be tailored for visual large climate network investigation (see as well Nocke et al. 2015). Therefore, we present a survey of requirements of network analysts and the related challenges and, as an overview for the interested practitioner, we review the state-of-the-art in climate network visualization techniques and tools, underpinned with concrete examples from climate network research and innovative solutions (e.g. alternative projections, 3D layered networks) implemented within the network visualization system GTX. References: Nocke, T., S. Buschmann, J. F. Donges, N. Marwan, H.-J. Schulz, and C. Tominski: Review: Visual analytics of climate networks, Nonlinear Processes in Geophysics, 22, 545-570, doi:10.5194/npg-22-545-2015, 2015

  18. Clean enough for industry? An airborne geophysical case study

    SciTech Connect

    Nyquist, J.E.; Beard, L.P.

    1996-11-01

    Data from two airborne geophysical surveys of the Department of Energy`s Oak Ridge Reservation (ORR) were extremely valuable in deciding whether a 1000-acre (400 hectare) parcel of the ORR should be leased to the City of Oak Ridge for industrial development. Our findings, based on electromagnetic and magnetic data, were incorporated in the federally mandated Environmental Assessment Statement (EAS), and in general supported claims that this land was never used as a hazardous waste disposal site. We estimated the amount of iron required to produce each anomaly using a simple dipole model. All anomalies with equivalent sources greater than approximately 1000 kg of iron were checked in the field, and the source of all but one identified as either a bridge, reinforced concrete debris, or a similarly benign object. Additionally, some smaller anomalies (equivalent sources of roughly 500 kg) have been checked; thus far, these also have innocuous sources. Airborne video proved invaluable in identifying logging equipment as the source of some of these anomalies. Geologic noise may account for some of the remaining anomalies. Naturally occurring accumulations of magnetic minerals in the soil on the ORR have been shown to produce anomalies which, at a sensor height of 30 in, are comparable to the anomaly produced by about 500 kg of iron. By comparison, the electronic noise of the magnetic gradiometer, 0.01- 0.02 nT/m, is equivalent to only about 50-100 kg of iron at a 30 m sensor height. The electromagnetic data, combined with field mapping of karst structures, provided evidence of a northeast-southwest striking conduit spanning the parcel. The possible existence of a karst conduit led the EAS authors to conclude that this is a {open_quotes}sensitive hydrologic setting.{close_quotes} We conclude that aerial geophysics is an extremely cost-effective, and efficient technique for screening large tracts of land for environmental characterization.

  19. Clean enough for industry? An airborne geophysical case study

    SciTech Connect

    Nyquist, J.E.; Beard, L.P.

    1996-02-01

    Data from two airborne geophysical surveys of the Department of Energy`s Oak Ridge Reservation (ORR) were extremely valuable in deciding whether a 1000-acre (400 hectare) parcel of the ORR should be released to the City of Oak Ridge for industrial development. Our findings, based on electromagnetic and magnetic data, were incorporated in the federally mandated Environmental Assessment Statement (EAS), and in general supported claims that this land was never used as a hazardous waste disposal site. We estimated the amount of iron required to produce each anomaly using a simple dipole model. All anomalies with equivalent sources greater than approximately 1000 kg of iron were checked in the field, and the source of all but one identified as either a bridge, reinforced concrete debris, or a similarly benign object. Additionally, some smaller anomalies (equivalent sources of roughly 500 kg) have been checked; thus far, these also have innocuous sources. Airborne video proved invaluable in identifying logging equipment as the source of some of these anomalies. Geologic noise may account for some of the remaining anomalies. Naturally occurring accumulations of magnetic minerals in the soil on the ORR have been shown to produce anomalies which, at a sensor height of 30 m, are comparable to the anomaly produced by about 500 kg of iron. By comparison, the electronic noise of the magnetic gradiometer, 0.01--0.02 nT/m, is equivalent to only about 50--100 kg of iron at a 30 m sensor height. The electromagnetic data, combined with field mapping of karst structures, provided evidence of a northeast-southwest striking conduit spanning the parcel. The possible existence of a karst conduit led the EAS authors to conclude that this is a ``sensitive hydrologic setting.`` We conclude that aerial geophysics is an extremely cost-effective, and efficient technique for screening large tracts of land for environmental characterization.

  20. Geophysical Characterization of the Borax Lake Hydrothermal System in the Alvord Desert, Southeastern Oregon.

    NASA Astrophysics Data System (ADS)

    Hess, S.; Paul, C.; Bradford, J.; Lyle, M.; Clement, W.; Liberty, L.; Myers, R.; Donaldson, P.

    2003-12-01

    We are conducting a detailed geophysical characterization of an active hydrothermal system as part of an interdisciplinary project aiming to study the link between the physical characteristics of hydrothermal systems and biota that occupy those systems. The Borax Lake Hydrothermal System (BLHS), consisting of Borax Lake and the surrounding hot springs, is located near the center of the Alvord Basin in southeastern Oregon. As a result of Basin and Range extension, the Alvord Basin is a north-south trending graben bounded by the Steens Mountains to the west and the Trout Creek Mountains to the east. We are using several geophysical techniques to generate both basin-wide and high-resolution local characterizations of the Alvord Basin and the BLHS. To date we have completed two scales of seismic reflection surveys: an east-west trending basin scale survey and a shallow (~10 - 300 m depth) 3D survey of the BLHS. The basin scale seismic survey consists of 11 km of 2D, 60 fold CMP data acquired with a 200 lb accelerated weight drop. We acquired the 3D survey of the BLHS using a 7.62x39 mm SKS rifle and 240 channel recording system. The 3D patch covers ~ 90,000 sq. m with a maximum inline offset aperture of 225 m, crossline aperture of 75 m, and 360 degree azimuthal coverage. Additionally, we have completed a regional total-field magnetic survey for a large portion of the Alvord Basin and a 3D transient electromagnetic (TEM) survey of the BLHS. The 3D TEM survey covers the central portion of the 3D seismic survey. Initial results from the regional magnetic and seismic surveys indicate a mid-basin basement high. The basement high appears to correlate with the northeast trending BLHS. Additionally, the cross-basin seismic profile clearly shows that recent deformation has primarily been along an eastward dipping normal fault that bounds the basement high to the east. This suggests that both spatial and temporal characteristics of deformation control hydrothermal activity

  1. Application of borehole geophysics in defining the wellhead protection area for a fractured crystalline bedrock aquifer

    USGS Publications Warehouse

    Vernon, J.H.; Paillet, F.L.; Pedler, W.H.; Griswold, W.J.

    1993-01-01

    Wellbore geophysical techniques were used to characterize fractures and flow in a bedrock aquifer at a site near Blackwater Brook in Dover, New Hampshire. The primary focus ofthis study was the development of a model to assist in evaluating the area surrounding a planned water supply well where contaminants introduced at the land surface might be induced to flow towards a pumping well. Well logs and geophysical surveys used in this study included lithologic logs based on examination of cuttings obtained during drilling; conventional caliper and natural gamma logs; video camera and acoustic televiewer surveys; highresolution vertical flow measurements under ambient conditions and during pumping; and borehole fluid conductivity logs obtained after the borehole fluid was replaced with deionized water. These surveys were used for several applications: 1) to define a conceptual model of aquifer structure to be used in groundwater exploration; 2) to estimate optimum locations for test and observation wells; and 3) to delineate a wellhead protection area (WHPA) for a planned water supply well. Integration of borehole data with surface geophysical and geological mapping data indicated that the study site lies along a northeast-trending intensely fractured contact zone between surface exposures of quartz monzonite and metasedimentary rocks. Four of five bedrock boreholes at the site were estimated to produce more than 150 gallons per minute (gpm) (568 L/min) of water during drilling. Aquifer testing and other investigations indicated that water flowed to the test well along fractures parallel to the northeast-trending contact zone and along other northeast and north-northwest-trending fractures. Statistical plots of fracture strikes showed frequency maxima in the same northeast and north-northwest directions, although additional maxima occurred in other directions. Flowmeter surveys and borehole fluid conductivity logging after fluid replacement were used to identify water

  2. Crump Geyser Exploration and Drilling Project. High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling

    SciTech Connect

    Fairbank, Brian D.; Smith, Nicole

    2015-06-10

    The Crump Geyser Exploration and Drilling Project – High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling ran from January 29, 2010 to September 30, 2013. During Phase 1 of the project, collection of all geophysical surveys was completed as outlined in the Statement of Project Objectives. In addition, a 5000-foot full sized exploration well was drilled by Ormat, and preexisting drilling data was discovered for multiple temperature gradient wells within the project area. Three dimensional modeling and interpretation of results from the geophysical surveys and drilling data gave confidence to move to the project into Phase 2 drilling. Geological and geophysical survey interpretations combined with existing downhole temperature data provided an ideal target for the first slim-hole drilled as the first task in Phase 2. Slim-hole 35-34 was drilled in September 2011 and tested temperature, lithology, and permeability along the primary range-bounding fault zone near its intersection with buried northwest-trending faults that have been identified using geophysical methods. Following analysis of the results of the first slim-hole 35-34, the second slim hole was not drilled and subsequent project tasks, including flowing differential self-potential (FDSP) surveys that were designed to detail the affect of production and injection on water flow in the shallow aquifer, were not completed. NGP sold the Crump project to Ormat in August 2014, afterwards, there was insufficient time and interest from Ormat available to complete the project objectives. NGP was unable to continue managing the award for a project they did not own due to liability issues and Novation of the award was not a viable option due to federal award timelines. NGP submitted a request to mutually terminate the award on February 18, 2015. The results of all of the technical surveys and drilling are included in this report. Fault interpretations from surface geology, aeromag

  3. Surface geophysics and porewater evaluation at the Lower Darby Creek Area Superfund Site, Philadelphia, Pennsylvania, 2013

    USGS Publications Warehouse

    Walker, Charles W.; Degnan, James R.; Brayton, Michael J.; Cruz, Roberto M.; Lorah, Michelle M.

    2015-01-01

    In cooperation with the U.S. Environmental Protection Agency (EPA), Region 3, the U.S. Geological Survey (USGS) is participating in an ongoing study to aid in the identification of subsurface heterogeneities that may act as preferential pathways for contaminant transport in and around the Lower Darby Creek Area (LDCA) Superfund Site, Philadelphia Pa. Lower Darby Creek, which flows into the Delaware River, borders the western part of the former landfill site. In 2013, the USGS conducted surface geophysics measurements and stream porewater sampling to provide additional data for EPA’s site characterization. This report contains data collected from field measurements of direct current (DC) resistivity, frequency-domain electromagnetic (FDEM) surveys, and stream porewater specific conductance (SC).

  4. GEOPHYSICAL INVESTIGATIONS OF THE ARCHAEOLOGICAL RESOURCES AT THE POWELL STAGE STATION

    SciTech Connect

    Hollie K. Gilbert; Julie B. Braun; Brenda R. Pace; Gail Heath; Clark Scott

    2009-04-01

    Within the boundaries of the Idaho National Laboratory, an ongoing archaeological investigation of a late 19th century stage station was expanded with the use of Electro-Magnetic and Magnetic geophysical surveying. The station known as the Powell Stage Station was a primary transportation hub on the Snake River Plain, bridging the gap between railroad supply depots in Blackfoot, Idaho and booming mining camps throughout Central Idaho. Initial investigations have shown a strong magnetic signature from a buried road and previously unknown features that were not detected by visual surface surveys. Data gained from this project aids in federally directed cultural resource and land management and use requirements and has contributed additional information for archeological interpretation and cultural resource preservation.

  5. Mississippi Canyon 194, Gulf of Mexico: Development case history/geophysical summary

    SciTech Connect

    Kohli, M. )

    1991-03-01

    A 3-D geophysical survey acquired at Cognac (MC 194 field) nine years after the first production shows the effect of reservoir drainage. A redevelopment program currently in progress targeted wells for oil bypassed due to poor sweep efficiency and/or small faults. Revised structural interpretation based on the 3-D showed several additional opportunities in new fault blocks. Attribute measurements were done at all levels where the pay sand was amplitude supported. These data were then tied in great detail with the geology and the production data available for the different reservoirs. Based on the results of the development wells, a good 3-D seismic survey can help locate fluid contacts, detect small faults ({plus minus}50 ft), and reduce dry hole and marginal well risks with better placement of wells.

  6. Combining geomorphological mapping and near surface geophysics (GPR and ERT) to study piping systems

    NASA Astrophysics Data System (ADS)

    Bernatek-Jakiel, Anita; Kondracka, Marta

    2016-12-01

    This paper aims to provide a more comprehensive characterization of piping systems in mountainous areas under a temperate climate using geomorphological mapping and geophysical methods (electrical resistivity tomography - ERT and ground penetrating radar - GPR). The significance of piping in gully formation and hillslope hydrology has been discussed for many years, and most of the studies are based on surface investigations. However, it seems that most surface investigations underestimate this subsurface process. Therefore, our purpose was to estimate the scale of piping activity based on both surface and subsurface investigations. We used geophysical methods to detect the boundary of lateral water movement fostering pipe development and recognize the internal structure of the underlying materials. The survey was carried out in the Bereźnica Wyżna catchment, in the Bieszczady Mountains. (Eastern Carpathians, Poland), where pipes develop in Cambisols at a mean depth of about 0.7-0.8 m. The geophysical techniques that were used are shown to be successful in identifying pipes. GPR data suggest that the density of piping systems is much larger than that detectible from surface observations alone. Pipe length can be > 6.5-9.2% (maximum = 49%) higher than what surface mapping suggests. Thus, the significance of piping in hillslope hydrology and gully formation can be greater than previously assumed. These results also draw attention to the scale of piping activity in the Carpathians, where this process has been neglected for many years. The ERT profiles reveal areas affected by piping as places of higher resistivity values, which are an effect of a higher content of air-filled pores (due to higher soil porosity, intense biological activity, and well-developed soil structure). In addition, the ERT profiles show that the pipes in the study area develop at the soil-bedrock interface, probably above the layers of shales or mudstones which create a water restrictive layer

  7. Unleashing Geophysics Data with Modern Formats and Services

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev

    2010-05-01

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

  9. Object Storage for Geophysical Data

    NASA Astrophysics Data System (ADS)

    Habermann, T.; Readey, J.

    2015-12-01

    Object storage systems (such as Amazon S3 or Ceph) have been shown to be cost-effective and highly scalable for data repositories in the Petabyte range and larger. However traditionally data storage used for geophysical software systems has centered on file-based systems and libraries such as NetCDF and HDF5. In this session we'll discuss the advantages and challenges of moving to an object store-based model for geophysical data. We'll review a proposed model for a geophysical data service that provides an API-compatible library for traditional NetCDF and HDF5 applications while providing high scalability and performance. One further advantage of this approach is that any dataset or dataset selection can be referenced as a URI. By using versioning, the data the URI references can be guaranteed to be unmodified, thus enabling reproducibility of referenced data.

  10. Continental crust: a geophysical approach

    SciTech Connect

    Meissner, R.

    1986-01-01

    This book develops an integrated and balanced picture of present knowledge of the continental crust. Crust and lithosphere are first defined, and the formation of crusts as a general planetary phenomenon is described. The background and methods of geophysical studies of the earth's crust and the collection of related geophysical parameters are examined. Creep and friction experiments and the various methods of radiometric age dating are addressed, and geophysical and geological investigations of the crustal structure in various age provinces of the continents are studied. Specific tectonic structures such as rifts, continental margins, and geothermal areas are discussed. Finally, an attempt is made to give a comprehensive view of the evolution of the continental crust and to collect and develop arguments for crustal accretion and recycling. 647 references.

  11. Time-domain electromagnetic surveys at Fort Irwin, San Bernardino County, California, 2010-12: Chapter F in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

    USGS Publications Warehouse

    Burgess, Matthew K.; Bedrosian, Paul A.; Buesch, David C.

    2014-01-01

    Between 2010 and 2012, a total of 79 time-domain electromagnetic (TEM) soundings were collected in 12 groundwater basins in the U.S. Army Fort Irwin National Training Center (NTC) study area to help improve the understanding of the hydrogeology of the NTC. The TEM data are discussed in this chapter in the context of geologic observations of the study area, the details of which are provided in the other chapters of this volume. Selection of locations for TEM soundings in unexplored basins was guided by gravity data that estimated depth to pre-Tertiary basement complex of crystalline rock and alluvial thickness. Some TEM data were collected near boreholes with geophysical logs. The TEM response at locations near boreholes was used to evaluate sounding data for areas without boreholes. TEM models also were used to guide site selection of subsequent boreholes drilled as part of this study. Following borehole completion, geophysical logs were used to ground-truth and reinterpret previously collected TEM data. This iterative process was used to site subsequent TEM soundings and borehole locations as the study progressed. Although each groundwater subbasin within the NTC boundaries was explored using the TEM method, collection of TEM data was focused in those basins identified as best suited for development of water resources. At the NTC, TEM estimates of some lithologic thicknesses and electrical properties in the unsaturated zone are in good accordance with borehole data; however, water-table elevations were not easily identifiable from TEM data.

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

    PubMed

    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.

  13. Integrated Geophysical Methods Applied to Geotechnical and Geohazard Engineering: From Qualitative to Quantitative Analysis and Interpretation

    NASA Astrophysics Data System (ADS)

    Hayashi, K.

    2014-12-01

    The Near-Surface is a region of day-to-day human activity on the earth. It is exposed to the natural phenomena which sometimes cause disasters. This presentation covers a broad spectrum of the geotechnical and geohazard ways of mitigating disaster and conserving the natural environment using geophysical methods and emphasizes the contribution of geophysics to such issues. The presentation focusses on the usefulness of geophysical surveys in providing information to mitigate disasters, rather than the theoretical details of a particular technique. Several techniques are introduced at the level of concept and application. Topics include various geohazard and geoenvironmental applications, such as for earthquake disaster mitigation, preventing floods triggered by tremendous rain, for environmental conservation and studying the effect of global warming. Among the geophysical techniques, the active and passive surface wave, refraction and resistivity methods are mainly highlighted. Together with the geophysical techniques, several related issues, such as performance-based design, standardization or regularization, internet access and databases are also discussed. The presentation discusses the application of geophysical methods to engineering investigations from non-uniqueness point of view and introduces the concepts of integrated and quantitative. Most geophysical analyses are essentially non-unique and it is very difficult to obtain unique and reliable engineering solutions from only one geophysical method (Fig. 1). The only practical way to improve the reliability of investigation is the joint use of several geophysical and geotechnical investigation methods, an integrated approach to geophysics. The result of a geophysical method is generally vague, here is a high-velocity layer, it may be bed rock, this low resistivity section may contain clayey soils. Such vague, qualitative and subjective interpretation is not worthwhile on general engineering design works

  14. Continued Geophysical Logging in the vicinity of the GMH Electronics Superfund Site near Roxboro, North Carolina

    USGS Publications Warehouse

    Antolino, Dominick J.; Chapman, Melinda J.

    2016-01-01

    The collection of borehole geophysical logs and images and continuous water-level data was conducted by the U.S. Geological Survey South Atlantic Water Science Center in the vicinity of the GMH Electronics Superfund site near Roxboro, North Carolina, during December 2012 through July 2015. The study purpose was part of a continued effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants. Previous work by the U.S. Geological Survey South Atlantic Water Science Center at the site involved similar data collection, in addition to surface geologic mapping and passive diffusion bag sampling within monitoring wells (Chapman and others, 2013). The continued data compilation efforts included the delineation of more than 900 subsurface features (primarily fracture orientations) in 10 open borehole wells. Geophysical logs, borehole imagery, pumping data, and heat-pulse flow measurements were collected and are presented within this data release.

  15. Hydrogeological modelling using geophysical data in groundwater protection projects

    NASA Astrophysics Data System (ADS)

    Nyari, Zs.; Szucs, P.; Tildy, P.

    2003-04-01

    In order to avoid the pollution of groundwater resources it is essential to be familiar with the conditions of water and contamination flow in the vicinity of the aquifer. Creating the hydrogeological model of a territory is basic part of a groundwater protection project. Reliable flow and transport models generally involve different sources of geoinformation. Different geophysical methods can provide the modellers with indispensable information to delineate wellhead protection zones as well as groundwater flow regimes (recharge, discharge and transition zones). To make a reliable and accurate model it is necessary to carry out appropriate geophysical surveys. Through two interesting case histories the presentation will illustrate the joint work of geophysicists and hydrogeologists resulting the hydrodynamic flow models of the investigated areas. The two cases represent two different types of aquifers (a bank-filtered water supply reserve and a sandy groundwater reservoir) where different geophysical survey types were applied. Besides the description of geophysical data acquisition and interpretation the main steps of creating the hydrogeological models of the areas will be explained.

  16. The Expanding Marketplace for Applied Geophysics

    NASA Astrophysics Data System (ADS)

    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

  17. New geophysical models related to heat sources in the geysers-clear lake region, California

    USGS Publications Warehouse

    Stanley, W.D.; Blakely, R.J.; ,

    1993-01-01

    We present an updated view of the geological and geophysical complexities of the upper crust in The Geysers-Clear Lake region in order to provide additional information regarding local structures and possible heat sources. New models and ideal-body analysis of the gravity data, new electromagnetic sounding models, and arguments made from other geophysical data sets suggest that many of the geophysical anomalies may be significantly affected by rock-property and physical-state variations in the upper 7 km, and not just to 'magma' at greater depths. We developed the new geophysical models in order to better understand constraints on the location of magma bodies.

  18. Geophysics for Military Construction Projects

    DTIC Science & Technology

    2010-09-01

    perform a gradiometer survey, which uses at least ERDC TR-10-9 12 two mobile sensors, typically oriented vertically and separated by a dis- tance...of 0.5 to 1 m. The gradiometer method has two advantages over the base station method: (1) no additional sensor needs to be set up, and (2) improved...pronounced in the data. The system used for this study is the Geometrics G-858 MagMapper (Figure 8) in a 1 m vertical gradiometer arrangement. Figure 8

  19. Reconnaissance geophysical study of Diablo Platform, Texas

    SciTech Connect

    Crosby, G.W.; Neff, W.H.; Schlecht, R.D.; Knaus, J.R.

    1988-01-01

    The Diablo platform lies in the southeastern part of the Basin and Range province of North America. Production from several zones within the Paleozoic section has been established both in basins and shelf edges of the surrounding area. A thick sequence of volcanic rocks covers the platform in Jeff Davis County, Texas. These rocks effectively prevent seismic investigation of the presumed sedimentary section below. Gravity, magnetic, and sparse well data were used in constructing an initial geologic model. A magnetotelluric survey consisting of 18 sites showed shallow resistive anomalies in agreement with magnetic anomalies. The magnetotelluric field data were modeled using the initial geologic model. From well control data, resistivity values for the volcanic rocks, sediments, and basement were set. After successive geophysical modeling, a final geologic model was constructed, which is reconciled with the magnetotelluric, magnetic, and well control data. A possible reef is present on the northeast side of the platform.

  20. Geophysical applications of satellite altimetry

    SciTech Connect

    Sandwell, D.T. )

    1991-01-01

    Publications related to geophysical applications of Seasat and Geosat altimetry are reviewed for the period 1987-1990. Problems discussed include geoid and gravity errors, regional geoid heights and gravity anomalies, local gravity field/flexure, plate tectonics, and gridded geoid heights/gravity anomalies. 99 refs.

  1. BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.

    USGS Publications Warehouse

    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.

  2. Geophysical Monitoring of Soil Stabilization Processes

    NASA Astrophysics Data System (ADS)

    Saneiyan, S.; Ntarlagiannis, D.; Werkema, D. D., Jr.

    2015-12-01

    Rapid growth of population led to the need of urban expansion into lands with problematic soils. For safe land development, the stability of problematic soils has to be enhanced. Among the many methods utilized, microbial induced carbonate precipitation (MICP) is of particular interest as a low energy, cost efficient and potentially long term ground improvement technique. As with other soil improvement methods though, high resolution temporal and spatial monitoring methods are missing. Geophysical methods can fill that gap, by efficiently complementing and extending current monitoring practices. Geophysical methods can offer low cost, no intrusive, continuous and spatially extensive monitoring of ground improvement techniques. With this work we test two of the most promising methods for monitoring MICP, Spectral Induced Polarization (SIP) and Nuclear Magnetic Resonance (NMR); additionally, we performed shear wave velocity measurements - the established standard on soil strength characterization - for direct comparison with NMR and SIP. The tests were performed in columns filled with unconsolidated porous media (e.g. Ottawa sand, glass beads) while binding was promoted with the addition of calcite. For the first part of the experiment we used abiotic methods for Calcite formation, while the second part involves microbial induced processes. The objective of this work is to quantify the sensitivity of NMR and SIP on soil strengthening as a result of calcite precipitation. Early results suggest that both methods, SIP and NMR, are sensitive calcite precipitation and dissolution processes.

  3. Investigating the probability of detection of typical cavity shapes through modelling and comparison of geophysical techniques

    NASA Astrophysics Data System (ADS)

    James, P.

    2011-12-01

    With a growing need for housing in the U.K., the government has proposed increased development of brownfield sites. However, old mine workings and natural cavities represent a potential hazard before, during and after construction on such sites, and add further complication to subsurface parameters. Cavities are hence a limitation to certain redevelopment and their detection is an ever important consideration. The current standard technique for cavity detection is a borehole grid, which is intrusive, non-continuous, slow and expensive. A new robust investigation standard in the detection of cavities is sought and geophysical techniques offer an attractive alternative. Geophysical techniques have previously been utilised successfully in the detection of cavities in various geologies, but still has an uncertain reputation in the engineering industry. Engineers are unsure of the techniques and are inclined to rely on well known techniques than utilise new technologies. Bad experiences with geophysics are commonly due to the indiscriminate choice of particular techniques. It is imperative that a geophysical survey is designed with the specific site and target in mind at all times, and the ability and judgement to rule out some, or all, techniques. To this author's knowledge no comparative software exists to aid technique choice. Also, previous modelling software limit the shapes of bodies and hence typical cavity shapes are not represented. Here, we introduce 3D modelling software (Matlab) which computes and compares the response to various cavity targets from a range of techniques (gravity, gravity gradient, magnetic, magnetic gradient and GPR). Typical near surface cavity shapes are modelled including shafts, bellpits, various lining and capping materials, and migrating voids. The probability of cavity detection is assessed in typical subsurface and noise conditions across a range of survey parameters. Techniques can be compared and the limits of detection distance

  4. Validating Prior Geological Scenario Uncertainty with Geophysical Data

    NASA Astrophysics Data System (ADS)

    Scheidt, C.; Jeong, C.; Mukerji, T.; Caers, J.

    2014-12-01

    Subsurface reservoir modelling, whether for groundwater, storage or oil/gas production relies on geophysical data for determining structure, rocks and fluid variations. The traditional approach depends on stochastic inversion of the geophysical image into subsurface models. However, in addition to geophysical data a wealth of geological information is available from analog or previous studies. Most of this information is ignored, and inversions resort to more mathematically-inspired priors often based on covariance models. In this presentation, using a real field application, we propose a method to validate a rich geological prior with geophysical data without the need for costly inversions. The result of this work is a wide, but geologically-realistic prior that can then be used in subsequent stochastic inversions. To achieve this, we propose to validate plausible geological models (from analog studies) with the observed geophysical data through a global, pattern-based measure of dissimilarity. This global dissimilarity measure is defined between the forward simulated geophysical response of a large variety of geologically plausible models and the observed field data. The proposed dissimilarity measure relies on a comparison of the wavelet decompositions between observed and forward simulated geophysical responses. The difference in frequency distribution of the wavelet coefficients is used via a JS-divergence measure to define the dissimilarity between all the subsurface models and the observed data. The proposed approach is applied to a real field offshore reservoir in West Africa, where a 3D seismic cube is available. The uncertain geological parameters defined for this case are the rock physic model, the infill channels size, depth, sinuosity, the proportion of sand/shale and the stacking patterns.

  5. Geophysical Institute. Biennial report, 1993-1994

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  7. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.J.; Keiswetter, D.

    1995-10-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits rapid geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected.

  8. Integration of remote sensing and geophysical techniques for coastal monitoring

    NASA Astrophysics Data System (ADS)

    Simoniello, T.; Carone, M. T.; Loperte, A.; Satriani, A.; Imbrenda, V.; D'Emilio, M.; Guariglia, A.

    2009-04-01

    Coastal areas are of great environmental, economic, social, cultural and recreational relevance; therefore, the implementation of suitable monitoring and protection actions is fundamental for their preservation and for assuring future use of this resource. Such actions have to be based on an ecosystem perspective for preserving coastal environment integrity and functioning and for planning sustainable resource management of both the marine and terrestrial components (ICZM-EU initiative). We implemented an integrated study based on remote sensing and geophysical techniques for monitoring a coastal area located along the Ionian side of Basilicata region (Southern Italy). This area, between the Bradano and Basento river mouths, is mainly characterized by a narrow shore (10-30 m) of fine sandy formations and by a pine forest planted in the first decade of 50's in order to preserve the coast and the inland cultivated areas. Due to drought and fire events and saltwater intrusion phenomena, such a forest is affected by a strong decline with consequent environmental problems. Multispectral satellite data were adopted for evaluating the spatio-temporal features of coastal vegetation and the structure of forested patterns. The increase or decrease in vegetation activity was analyzed from trends estimated on a time series of NDVI (Normalized Difference Vegetation Index) maps. The fragmentation/connection levels of vegetated patterns was assessed form a set of landscape ecology metrics elaborated at different structure scales (patch, class and landscape) on satellite cover classifications. Information on shoreline changes were derived form a multi-source data set (satellite data, field-GPS surveys and Aerial Laser Scanner acquisitions) by taking also into account tidal effects. Geophysical campaigns were performed for characterizing soil features and limits of salty water infiltrations. Form vertical resistivity soundings (VES), soil resistivity maps at different a deeps (0

  9. The facts on file. Dictionary of geology and geophysics

    SciTech Connect

    Lapidus, D.F.; Coates, D.R.

    1987-01-01

    This reference to the basic vocabulary of geology and geophysics has more than 3,000 clear and concise entries defining the entire range of geological phenomena. This book covers such areas as types of rocks and rock formations, deformation processes such as erosion and plate tectonics, volcanoes, glaciers and their effects on topography, geodesy and survey methods, earthquakes and seismology, fuels and mineral deposits.

  10. Notes on interpretation of geophysical data over areas of mineralization in Afghanistan

    USGS Publications Warehouse

    Drenth, Benjamin J.

    2011-01-01

    Afghanistan has the potential to contain substantial metallic mineral resources. Although valuable mineral deposits have been identified, much of the country's potential remains unknown. Geophysical surveys, particularly those conducted from airborne platforms, are a well-accepted and cost-effective method for obtaining information on the geological setting of a given area. This report summarizes interpretive findings from various geophysical surveys over selected mineral targets in Afghanistan, highlighting what existing data tell us. These interpretations are mainly qualitative in nature, because of the low resolution of available geophysical data. Geophysical data and simple interpretations are included for these six areas and deposit types: (1) Aynak: Sedimentary-hosted copper; (2) Zarkashan: Porphyry copper; (3) Kundalan: Porphyry copper; (4) Dusar Shaida: Volcanic-hosted massive sulphide; (5) Khanneshin: Carbonatite-hosted rare earth element; and (6) Chagai Hills: Porphyry copper.

  11. Marine Magnetic Data Holdings of World Data Center-a for Marine Geology and Geophysics

    NASA Technical Reports Server (NTRS)

    Sharman, George F.; Metzger, Dan

    1992-01-01

    The World Data Center-A for Marine Geology and Geophysics is co-located with the Marine Geology & Geophysical Data Center, Boulder, CO. Fifteen million digital marine magnetic trackline measurements are managed within the GEOphysical DAta System (GEODAS). The bulk of these data were collected with proton precision magnetometers under Transit Satellite navigational control. Along-track sampling averages about 1 sample per kilometer, while spatial density, a function of ship's track and survey pattern, range from 4 to 0.02 data points/sq. km. In the near future, the entire geophysical data set will be available on CD-ROM. The Marine Geology and Geophysics Division (World Data Center-A for MGG), of the National Geophysical Data Center, handles a broad spectrum of marine geophysical data, including measurements of bathymetry, magnetics, gravity, seismic reflection subbottom profiles, and side-scan images acquired by ships throughout the world's oceans. Digital data encompass the first three, while the latter two are in analog form, recorded on 35mm microfilm. The marine geophysical digital trackline data are contained in the GEODAS data base which includes 11.6 million nautical miles of cruise trackline coverage contributed by more than 70 organizations worldwide. The inventory includes data from 3206 cruises with 33 million digital records and indexing to 5.3 million track miles of analog data on microfilm.

  12. Gender diversity in Geophysics

    NASA Astrophysics Data System (ADS)

    Deuss, Arwen

    2016-04-01

    As a successful female scientist with two ERC grants, first as a starter and now a consolidator, I was priviliged that I personally never perceived any obstacles. At the same time, I am also aware that the statistics tell a different story when you look at the whole population. I will give an account and tell some anecdotes about what I think helped me, though it is important to be careful not to generalise my personal strategies. My main strategy is to publish papers in international journals and obtain personal grants. This also means limiting additional responsibilities that will not benefit my publication record or potential success in grant applications. The second important factor is that I have always been surrounded by people who give me confidence and support me, such as my parents, partner and senior colleagues who have acted (mostly unofficially) as mentor. In the workplace, there is a great advantage in having a senior mentor, who needs to be a successful academic(!), and can help with any career related issues and choices. But also at home, a supportive partner who will take an equal share in childcare responsibilities, makes a great difference. Are there any new strategies that we can implement to further overcome barriers? Not by design, but by coincidence, my research team for my ERC starting grant consisted largely of female PhD students and postdocs. The great things was that they stimulated each other, all became very confident, and several of them now have academics jobs at prestigious universities in the US and Europe. They believe in themselves, which is the first step in overcoming any potential barriers they may encounter later in their careers.

  13. Geophysical fields of a megalopolis

    NASA Astrophysics Data System (ADS)

    Spivak, A. A.; Loktev, D. N.; Rybnov, Yu. S.; Soloviev, S. P.; Kharlamov, V. A.

    2016-12-01

    A description of the Center of Geophysical Monitoring for Systematic Investigation of Negative Consequences for the Human Environment and Infrastructure of the City of Moscow Resulting from Natural and Technogenic Factors, which is part of the Institute of Geosphere Dynamics of the Russian Academy of Sciences (IGD RAS), is presented. The results of synchronous observations of the seismic vibrations, electric and acoustic fields, and atmospheric meteoparameters performed at the Center and in the Mikhnevo Geophysical observatory of IGD RAS situated outside of the zone of the Moscow influence are examined. It is shown that the megalopolis influence consists of an increase in the amplitudes of the physical fields, a change in their spectral composition, and the violation of natural periodicities. A technogenic component that has a considerable impact on the natural physical processes in the surface atmosphere is an important factor that characterizes a megalopolis.

  14. Smith heads Reviews of Geophysics

    NASA Astrophysics Data System (ADS)

    On January 1, Jim Smith began his term as editor-in-chief of Reviews of Geophysics. As editor-in-chief, he leads the board of editors in enhancing the journal's role as an integrating force in the geophysical sciences by providing timely overviews of current research and its trends. Smith is already beginning to fulfill the journal's role of providing review papers on topics of broad interest to Union members as well as the occasional definitive review paper on selected topics of narrower focus. Smith will lead the editorial board until December 31, 2000. Michael Coffey, Tommy Dickey, James Horwitz, Roelof Snieder, and Thomas Torgersen have been appointed as editors to serve with Smith. At least one more editor will be named to round out the disciplinary expertise on the board.

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

    DTIC Science & Technology

    2012-04-01

    of Alabama Press, Tuscaloosa. 154 Ernenwein, E. G. and M . L . Hargrave. 2007. Archaeological Geophysics for DoD Field Use: a Guide for New and...G. Ernenwein, M . L . Hargrave, T. Sever, D. Harmon, F. Limp, B. Howell, M . Koons and J. Tullis. 2006. New Approaches to the Use and Integration of...American Antiquity 48:675-706. 156 Somers, L . E., M . L . Hargrave and contributions from Janet E. Simms. 2003. Geophysical Surveys in

  16. About well-posed definition of geophysical fields'

    NASA Astrophysics Data System (ADS)

    Ermokhine, Konstantin; Zhdanova, Ludmila; Litvinova, Tamara

    2013-04-01

    (in an underground half-space) a field measured at the surface, allows you to make the interpretation of geophysical data, to build a cross-section, determine the depth, the approximate shape and size of the sources measured at the surface of the geophysical fields. Appliance of the method are any geophysical surveys: magnetic, gravimetric, electrical exploration, seismic, geochemical surveying, etc. Method was tested on model examples, and practical data. The results are confirmed by drilling.

  17. GEOPHYSICS: Atmosphere Drives Earth's Tipsiness.

    PubMed

    Kerr, R A

    2000-08-04

    For more than a century, geophysicists who track Earth's rotation have sensed a rhythmic unsteadiness about the planet, an ever-so-slight wobbling whose source remained frustratingly mysterious. But researchers have been homing in on the roots of the so-called Chandler wobble, and now a report in the 1 August issue of Geophysical Research Letters fingers the shifting pressures of the deep sea and ultimately the fickle winds of the atmosphere.

  18. Geophysical Fluid Flow Cell Simulation

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Computer simulation of atmospheric flow corresponds well to imges taken during the second Geophysical Fluid Flow Cell (BFFC) mission. The top shows a view from the pole, while the bottom shows a view from the equator. Red corresponds to hot fluid rising while blue shows cold fluid falling. This simulation was developed by Anil Deane of the University of Maryland, College Park and Paul Fischer of Argorne National Laboratory. Credit: NASA/Goddard Space Flight Center

  19. Geophysical flight line flying and flight path recovery utilizing the Litton LTN-76 inertial navigation system

    SciTech Connect

    Mitkus, A.F.; Cater, D.; Farmer, P.F.; Gay, S.P. Jr.

    1981-11-01

    The Litton LTN-76 Inertial Navigation Systems (INS) with Inertial Track guidance System (ITGS) software is geared toward the airborne survey industry. This report is a summary of tests performed with the LTN-76 designed to fly an airborne geophysical survey as well as to recover the subsequent flight path utilizing INS derived coordinates.

  20. 77 FR 6580 - National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ....S. Geological Survey National Cooperative Geologic Mapping Program (NCGMP) and National Geological and Geophysical Data Preservation Program (NGGDPP) Advisory Committee AGENCY: U.S. Geological Survey... Standard Time. The Committee will hear updates on progress of the NCGMP toward fulfilling the purposes...

  1. Geophysical monitoring technology for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Ma, Jin-Feng; Li, Lin; Wang, Hao-Fan; Tan, Ming-You; Cui, Shi-Ling; Zhang, Yun-Yin; Qu, Zhi-Peng; Jia, Ling-Yun; Zhang, Shu-Hai

    2016-06-01

    Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.

  2. Geophysical delineation of acidity and salinity in the Central Manitoba gold mine tailings pile, Manitoba, Canada

    NASA Astrophysics Data System (ADS)

    Tycholiz, C.; Ferguson, I. J.; Sherriff, B. L.; Cordeiro, M.; Sri Ranjan, R.; Pérez-Flores, M. A.

    2016-08-01

    Surface electrical and electromagnetic geophysical methods can map enhanced electrical conductivity caused by acid mine drainage in mine tailings piles. In this case study, we investigate quantitative relationships between geophysical responses and the electrical conductivity, acidity and salinity of tailing samples at the Central Manitoba Mine tailings in Manitoba, Canada. Previous electromagnetic surveys at the site identified zones of enhanced conductivity that were hypothesized to be caused by acid mine drainage. In the present study, high-resolution EM31 and DC-resistivity measurements were made on a profile through a zone of enhanced conductivity and laboratory measurements of salinity and pH were made on saturation paste extracts from an array of tailing samples collected from the upper 2 m of tailings along the profile. Observed spatial correlation of pH and pore-fluid salinity in the tailings samples confirms that the enhanced conductivity in the Central Manitoba Mine tailings is due to acid mine drainage. Contoured cross-sections of the data indicate that the acid mine drainage is concentrated near the base of the oxidized zone in the thicker parts of the tailings pile. The zone of increased acidity extends to the surface on sloping margins causing an increase in apparent conductivity in shallow penetrating geophysical responses. The quantitative relationship between measured pH and salinity shows that the conductivity increase associated with the acid mine drainage is due only in part to conduction by ions produced from dissociation of sulfuric acid. Comparison of the observations with fluid conductivity estimates based on statistical relationships of pH and ion concentrations in water samples from across the tailings pile shows that Ca2 + and Mg2 + ions also make significant contributions to the conductivity at all values of pH and Cu2 +, Al3 + and Fe3 + ions make additional contributions at low pH. Variability in the measured conductivity at constant

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

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

  5. Geophysical Model Research and Results

    SciTech Connect

    Pasyanos, M; Walter, W; Tkalcic, H; Franz, G; Flanagan, M

    2004-07-07

    Geophysical models constitute an important component of calibration for nuclear explosion monitoring. We will focus on four major topics: (1) a priori geophysical models, (2) surface wave models, (3) receiver function derived profiles, and (4) stochastic geophysical models. The first, a priori models, can be used to predict a host of geophysical measurements, such as body wave travel times, and can be derived from direct regional studies or even by geophysical analogy. Use of these models is particularly important in aseismic regions or regions without seismic stations, where data of direct measurements might not exist. Lawrence Livermore National Laboratory (LLNL) has developed the Western Eurasia and North Africa (WENA) model which has been evaluated using a number of data sets, including travel times, surface waves, receiver functions, and waveform analysis (Pasyanos et al., 2004). We have joined this model with our Yellow Sea - Korean Peninsula (YSKP) model and the Los Alamos National Laboratory (LANL) East Asia model to construct a model for all of Eurasia and North Africa. Secondly, we continue to improve upon our surface wave model by adding more paths. This has allowed us to expand the region to all of Eurasia and into Africa, increase the resolution of our model, and extend results to even shorter periods (7 sec). High-resolution models exist for the Middle East and the YSKP region. The surface wave results can be inverted either alone, or in conjunction with other data, to derive models of the crust and upper mantle structure. We are also using receiver functions, in joint inversions with the surface waves, to produce profiles directly under seismic stations throughout the region. In a collaborative project with Ammon, et al., they have been focusing on stations throughout western Eurasia and North Africa, while we have been focusing on LLNL deployments in the Middle East, including Kuwait, Jordan, and the United Arab Emirates. Finally, we have been

  6. Water-quality and geophysical data for three study sites within the Williston Basin and Prairie Pothole Region

    USGS Publications Warehouse

    Preston, Todd M.; Smith, Bruce D.; Thamke, Joanna N.; Chesley-Preston, Tara

    2012-01-01

    This report is a data release for water geochemical sample analyses and geophysical surveys for three sites within the Williston Basin and Prairie Pothole Region of Montana and North Dakota. The data collection sites and procedures are described.

  7. Applied Geophysics Opportunities in the Petroleum Industry

    NASA Astrophysics Data System (ADS)

    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.

  8. Three-Dimensional Surface Geophysical Exploration of the 200-Series Tanks at the 241-C Tank Farm

    SciTech Connect

    Crook, N.; McNeill, M.; Dunham, Ralph; Glaser, Danney R.

    2014-02-26

    A surface geophysical exploration (SGE) survey using direct current electrical resistivity was conducted within the C Tank Farm in the vicinity of the 200-Series tanks at the Hanford Site near Richland, Washington. This survey was the second successful SGE survey to utilize the Geotection(TM)-180 Resistivity Monitoring System which facilitated a much larger survey size and faster data acquisition rate. The primary objective of the C Tank Farm SGE survey was to provide geophysical data and subsurface imaging results to support the Phase 2 RCRA Facility Investigation, as outlined in the Phase 2 RCRA Facility Investigation / Corrective Measures work plan RPP-PLAN-39114.

  9. Progress in geophysical fluid dynamics

    NASA Astrophysics Data System (ADS)

    Robinson, Allan R.

    Geophysical fluid dynamics deals with the motions and physics of the atmosphere, oceans and interior of the earth and other planets: the winds, the swirls, the currents that occur on myriads of scales from millimeter to climatological. Explanations of natural phenomena, basic processes and abstractions are sought. The rotation of the earth, the buoyancy of its fluids and the tendency towards large-scale turbulence characterize these flows. But geophysical fluid dynamics is importantly a part of modern fluid dynamics which is contributing to the development of nonlinear mechanics generally. Some general insights are emerging for nonlinear systems which must be regarded as partly deterministic and partly random or which are complex and aperiodic. Contributions from geophysical fluid dynamics come from its methodology, from the experience of examples, and from the perspective provided by its unique scale. Contributions have been made to turbulent, chaotic and coherently structured nonlinear process research. Turbulent vortices larger than man himself naturally invite detailed investigation and deterministic physical studies. Examples are storms in the atmosphere and large ring vortices spun off by the Gulf Stream current in mid-ocean. The statistics of these events determine critical aspects of the general circulations. Fluid dynamicists generally now know that it is often relevant or necessary to study local dynamical processes of typical eddies even though only the average properties of the flow are of interest; progress in understanding the turbulent boundary layer in pipes involves the study of millimeter-scale vortices. Weather-related studies were seminal to the construction of the new scientific field of chaos. Coherent vortices abound of which the Great Red Spot of Jupiter is a spectacular example. Geophysical fluid dynamicists have been among forefront researchers in exploiting the steadily increasing speed and capacity of modern computers. Supercomputers

  10. Getting to the Root of the Problem - Assessing Crop Water Uptake Using Geophysics

    NASA Astrophysics Data System (ADS)

    Binley, A. M.; Shanahan, P. W.; Watts, C. W.; Ashton, R.; Whalley, W. R.

    2015-12-01

    Increasing demands on the agricultural industry to produce higher crop yields and provide sustainable agriculture solutions under changing climate and land use is, in part, constrained by the tools available to explore crop-soil-water interactions at the field scale. Traditional measurements of soil moisture offer information about local scale processes, or are resource intensive for investigation at the large scale. As in many other areas of hydrology, geophysical techniques are emerging as potentially valuable methods for large scale investigations, although the full potential of these methods is yet to be realised. We report here on a field-based experimental study in which electrical resistivity tomography and multi-coil electromagnetic induction methods were used to monitor changes in soil electrical conductivity over the growing season of winter wheat (Triticum aestivum L.). Changes in electrical conductivity was used as a proxy for changes in soil water content in an attempt to reveal different characteristics of soil water uptake by 23 different lines of wheat. The study was performed in a randomised block experiment using replicate plots for each wheat line. Neutron probe data and penetrometer measurements collected during the study permit a comparison with direct estimates of changes in soil water and changes in soil strength, respectively. The results of the geophysical surveys appear consistent with these independent measurements. Additional constraints in interpretation due to the effect of soil cracking are also explored. It appears that electrical conductivity is potentially useful as an indicator of changes to soil water in such agricultural environments. Resolving subtle differences between different lines of wheat may be challenging and limit the value of these methods in breeding programs. However, the ability to monitor changes in soil water status over large areas with vehicle-mounted geophysical instrumentation remains a major potential

  11. Constraining 3D Process Sedimentological Models to Geophysical Data Using Image Quilting

    NASA Astrophysics Data System (ADS)

    Tahmasebi, P.; Da Pra, A.; Pontiggia, M.; Caers, J.

    2014-12-01

    3D process geological models, whether for carbonate or sedimentological systems, have been proposed for modeling realistic subsurface heterogeneity. The problem with such forward process models is that they are not constrained to any subsurface data whether to wells or geophysical surveys. We propose a new method for realistic geological modeling of complex heterogeneity by hybridizing 3D process modeling of geological deposition with conditioning by means of a novel multiple-point geostatistics (MPS) technique termed image quilting (IQ). Image quilting is a pattern-based techniques that stiches together patterns extracted from training images to generate stochastic realizations that look like the training image. In this paper, we illustrate how 3D process model realizations can be used as training images in image quilting. To constrain the realization to seismic data we first interpret each facies in the geophysical data. These interpretation, while overly smooth and not reflecting finer scale variation are used as auxiliary variables in the generation of the image quilting realizations. To condition to well data, we first perform a kriging of the well data to generate a kriging map and kriging variance. The kriging map is used as additional auxiliary variable while the kriging variance is used as a weight given to the kriging derived auxiliary variable. We present an application to a giant offshore reservoir. Starting from seismic advanced attribute analysis and sedimentological interpretation, we build the 3D sedimentological process based model and use it as non-stationary training image for conditional image quilting.

  12. Geophysical Monitoring at the Aquistore CO2 Storage Site, Saskatchewan, Canada (Invited)

    NASA Astrophysics Data System (ADS)

    White, D. J.

    2013-12-01

    The Aquistore Project, located near Estevan, Saskatchewan, is designed to demonstrate CO2 storage in a deep saline aquifer. CO2 captured from the nearby Boundary Dam coal-fired power plant will be injected into a brine-filled sandstone formation at ~3300 m depth, starting in November, 2013. A key element of the Aquistore research program is the further development of geophysical methods to monitor the security and subsurface distribution of the injected CO2. Toward this end, a spectrum of geophysical techniques are being tested at the Aquistore site. Various time-lapse seismic methods, including 3D surface and vertical seismic profiles (VSP) as well as crosswell seismic tomography, are designed to provide monitoring of the CO2 plume. Novel components of the seismic monitoring include use of a sparse permanent array and borehole recording using a fiber optic distributed acoustic sensor (DAS) system. Gravity and electromagnetic methods are providing complementary monitoring. Pre-injection baseline surveys have been acquired for each of these methods. In addition, continuous pre-injection monitoring has been ongoing since the summer of 2012 to establish background surface deformation patterns and local seismicity prior to the start of CO2 injection. A network of GPS stations, surface tiltmeters and InSAR reflectors has been deployed to monitor injection-related surface deformation. Passive seismic monitoring is being conducted using two orthogonal linear arrays of surface geophones.

  13. Geophysical Monitoring at the Aquistore CO2 Storage Site, Saskatchewan, Canada (Invited)

    NASA Astrophysics Data System (ADS)

    Wang, L.; Huang, Z.; Xu, M.; Mi, N.; Yu, D.; Li, H.

    2011-12-01

    The Aquistore Project, located near Estevan, Saskatchewan, is designed to demonstrate CO2 storage in a deep saline aquifer. CO2 captured from the nearby Boundary Dam coal-fired power plant will be injected into a brine-filled sandstone formation at ~3300 m depth, starting in November, 2013. A key element of the Aquistore research program is the further development of geophysical methods to monitor the security and subsurface distribution of the injected CO2. Toward this end, a spectrum of geophysical techniques are being tested at the Aquistore site. Various time-lapse seismic methods, including 3D surface and vertical seismic profiles (VSP) as well as crosswell seismic tomography, are designed to provide monitoring of the CO2 plume. Novel components of the seismic monitoring include use of a sparse permanent array and borehole recording using a fiber optic distributed acoustic sensor (DAS) system. Gravity and electromagnetic methods are providing complementary monitoring. Pre-injection baseline surveys have been acquired for each of these methods. In addition, continuous pre-injection monitoring has been ongoing since the summer of 2012 to establish background surface deformation patterns and local seismicity prior to the start of CO2 injection. A network of GPS stations, surface tiltmeters and InSAR reflectors has been deployed to monitor injection-related surface deformation. Passive seismic monitoring is being conducted using two orthogonal linear arrays of surface geophones.

  14. Interplay Between the Equatorial Geophysical Processes

    NASA Astrophysics Data System (ADS)

    Sridharan, R.

    2006-11-01

    r_sridharanspl@yahoo.com With the sun as the main driving force, the Equatorial Ionosphere- thermosphere system supports a variety of Geophysical phenomena, essentially controlled by the neutral dynamical and electro dynamical processes that are peculiar to this region. All the neutral atmospheric parameters and the ionospheric parameters show a large variability like the diurnal, seasonal semi annual, annual, solar activity and those that are geomagnetic activity dependent. In addition, there is interplay between the ionized and the neutral atmospheric constituents. They manifest themselves as the Equatorial Electrojet (EEJ), Equatorial Ionization Anomaly (EIA), Equatorial Spread F (ESF), Equatorial Temperature and Wind Anomaly (ETWA). Recent studies have revealed that these phenomena, though apparently might show up as independent ones, are in reality interlinked. The interplay between these equatorial processes forms the theme for the present talk.

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

    NASA Astrophysics Data System (ADS)

    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

  16. Geophysical Methodologies for the Characterisation of Gas Hydrate Sediments

    NASA Astrophysics Data System (ADS)

    Lovell, M.; Jackson, P.; Gunn, D.; Rochelle, C.; Bateman, K.; Nelder, V.; Culshaw, M.; Rees, J.; Francis, T.; Roberts, J.; Schultheiss, P.

    2001-12-01

    The study of natural gas hydrate cores in the laboratory is currently limited by their instability at ambient conditions. Proposals to sample hydrates using pressure coring techniques and sample transfer chambers on-board ship are, however, in place and technical developments to enable these are well advanced (c.f. the HYACINTH project and ODP Leg 204). There is, however, a need to try to characterise the nature and extent of any gas hydrate within the pressurised sample prior to depressurising, opening and subsampling. The ability to geophysically characterise gas hydrates remotely while still in the pressurised core barrel may provide a route to detailing their physical extent and nature. With this objective, experiments to manufacture a range of synthetic gas hydrate morphologies in a range of sediments in the laboratory are in progress. To date we have succeeded in manufacturing a range of both pure and sediment-hosted CO2 hydrates. Continuing experiments are developing a range of geometrical and internal structures and fabrics (from massive to disseminated) using different sediment-hosts. These generic hydrate groups will provide a basis for non-invasive geophysical characterisation of hydrate morphologies. From these results protocols will be established to guide the geophysical logging of natural sediment-hydrate core maintained under pressure in lab transfer chambers on board the drillship, using the hyperbaric Geotek Core Logger. This will enable the characterisation and classification of hydrates sampled during ODP Leg 204 (and during subsequent hydrate sampling operations not restricted to ODP). While new insight will be gained into geophysical modelling of hydrate behaviour, it will also guide the development of sampling programs, prior to depressurising and initiating dissociation. This will allow detailed planning of shipboard scientific work utilising these rare and precious samples. This new knowledge will enhance geophysical survey data, better

  17. U.S. Geological Survey scientific activities in the exploration of Antarctica: 1946-2006 record of personnel in Antarctica and their postal cachets: U.S. Navy (1946-48, 1954-60), International Geophysical Year (1957-58), and USGS (1960-2006)

    USGS Publications Warehouse

    Meunier, Tony K.; Williams, Richard S.; Ferrigno, Jane G.

    2007-01-01

    Antarctica, a vast region encompassing 13.2 million km2 (5.1 million mi2), is considered to be one of the most important scientific laboratories on Earth. During the past 60 years, the USGS, in collaboration and with logistical support from the National Science Foundation's Office of Polar Programs, has sent 325 USGS scientists to Antarctica to work on a wide range of projects: 169 personnel from the NMD (mostly aerial photography, surveying, and geodesy, primarily used for the modern mapping of Antarctica), 138 personnel from the GD (mostly geophysical and geological studies onshore and offshore), 15 personnel from the WRD (mostly hydrological/glaciological studies in the McMurdo Dry Valleys), 2 personnel from the BRD (microbiological studies in the McMurdo Dry Valleys), and 1 person from the Director's Office (P. Patrick Leahy, Acting Director, 2005–06 austral field season). Three GD scientists and three NMD scientists have carried out field work in Antarctica 9 or more times: John C. Behrendt (15), who started in 1956–57 and published two memoirs (Behrendt, 1998, 2005), Arthur B. Ford (10), who started in 1960–61, and Gary D. Clow (9), who started in 1985–86; Larry D. Hothem (12), who began as a winter-over geodesist at Mawson Station in 1968–69, and Jerry L. Mullins (12), who started in 1982–83 and followed in the legendary footsteps of his NMD predecessor, William R. MacDonald (9), who started in 1960–61 and supervised the acquisition of more than 1,000,000 square miles of aerial photography of Antarctica. This report provides a record as complete as possible, of USGS and non-USGS collaborating personnel in Antarctica from 1946–2006, the geographic locations of their work, and their scientific/engineering disciplines represented. Postal cachets for each year follow the table of personnel and scientific activities in the exploration of Antarctica during those 60 years. To commemorate special events and projects in Antarctica, it became an

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

    SciTech Connect

    Not Available

    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.

  19. Geophysical Model Applications for Monitoring

    SciTech Connect

    Pasyanos, M; Walter, W; Tkalcic, H; Franz, G; Gok, R; Rodgers, A

    2005-07-11

    Geophysical models constitute an important component of calibration for nuclear explosion monitoring. We will focus on four major topics and their applications: (1) surface wave models, (2) receiver function profiles, (3) regional tomography models, and (4) stochastic geophysical models. First, we continue to improve upon our surface wave model by adding more paths. This has allowed us to expand the region to all of Eurasia and into Africa, increase the resolution of our model, and extend results to even shorter periods (7 sec). High-resolution models exist for the Middle East and the YSKP region. The surface wave results can be inverted either alone, or in conjunction with other data, to derive models of the crust and upper mantle structure. One application of the group velocities is to construct phase-matched filters in combination with regional surface-wave magnitude formulas to improve the mb:Ms discriminant and extend it to smaller magnitude events. Next, we are using receiver functions, in joint inversions with the surface waves, to produce profiles directly under seismic stations throughout the region. In the past year, we have been focusing on deployments throughout the Middle East, including the Arabian Peninsula and Turkey. By assembling the results from many stations, we can see how regional seismic phases are affected by complicated upper mantle structure, including lithospheric thickness and anisotropy. The next geophysical model item, regional tomography models, can be used to predict regional travel times such as Pn and Sn. The times derived by the models can be used as a background model for empirical measurements or, where these don't exist, simply used as is. Finally, we have been exploring methodologies such as Markov Chain Monte Carlo (MCMC) to generate data-driven stochastic models. We have applied this technique to the YSKP region using surface wave dispersion data, body wave travel time data, receiver functions, and gravity data. The models

  20. Studies in geophysics: Active tectonics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Active tectonics is defined within the study as tectonic movements that are expected to occur within a future time span of concern to society. Such movements and their associated hazards include earthquakes, volcanic eruptions, and land subsidence and emergence. The entire range of geology, geophysics, and geodesy is, to some extent, pertinent to this topic. The needs for useful forecasts of tectonic activity, so that actions may be taken to mitigate hazards, call for special attention to ongoing tectonic activity. Further progress in understanding active tectonics depends on continued research. Particularly important is improvement in the accuracy of dating techniques for recent geologic materials.

  1. COTHERM: Geophysical Modeling of High Enthalpy Geothermal Systems

    NASA Astrophysics Data System (ADS)

    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

  2. Environmental and Engineering Geophysical University at SAGEEP 2008: Geophysical Instruction for Non-Geophysicists

    SciTech Connect

    Jeffrey G. Paine

    2009-03-13

    The Environmental and Engineering Geophysical Society (EEGS), a nonprofit professional organization, conducted an educational series of seminars at the Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP) in Philadelphia in April 2008. The purpose of these seminars, conducted under the name Environmental and Engineering Geophysical University (EEGU) over three days in parallel with the regular SAGEEP technical sessions, was to introduce nontraditional geophysical conference attendees to the appropriate use of geophysics in environmental and engineering projects. Five half-day, classroom-style sessions were led by recognized experts in the application of seismic, electrical, gravity, magnetics, and ground-penetrating radar methods. Classroom sessions were intended to educate regulators, environmental program managers, consultants, and students who are new to near-surface geophysics or are interested in learning how to incorporate appropriate geophysical approaches into characterization or remediation programs or evaluate the suitability of geophysical methods for general classes of environmental or engineering problems.

  3. Geophysical Characterization for a CO2 Sequestration Potential in the Ohio River Valley Region

    NASA Astrophysics Data System (ADS)

    Gupta, N.; Jagucki, P.; Meggyesy, D.; Janosy, R.; Sminchak, J.; Ramakrishan, T.; Boyd, A.

    2003-12-01

    A site at the American Electric Power's (AEP) Mountaineer Power Plant, WV in the Ohio River Valley in the Midwestern U.S., a region with the economy heavily dependent on fossil fuels, such as coal, oil, and gas, is being evaluated to determine the potential for geologic sequestration. The project is supported by the U.S. Department of Energy, Battelle, AEP, BP, The Ohio Air Quality Development Office, and Schlumberger. The major objective of the current phase is to characterize the reservoir at the plant site. Future decisions with regard to CO2 injection will be subject to the evaluated reservoir properties. The effort includes acquisition of 2-dimensional seismic data, assessment of regional geology, drilling to PreCambrian rocks and formation analysis and testing in a 2,800 meters deep well, reservoir simulations, risk assessment, and stakeholder outreach. The test well reached total depth in summer 2003. Wireline logging and reservoir testing was performed for each section of the borehole, including extensive tests in the lowermost 885 meters to estimate formation properties and pressure gradients. The logs included gamma-ray, neutron and density, and array resistivity, magnetic resonance relaxation for permeability information, elemental composition via capture spectroscopy, and resistivity based formation image. The seismic survey was conducted over approximately 11 miles along 2 lines: one along strike and one along dip. The results of the geophysical surveys combined with the field observations provide an integrated assessment of the major injection parameters for the two main injection reservoirs of interest, the Rose Run Formation and the Lower Maryville formation. In addition, the properties of the potential caprock formations overlying the candidate injection zones were also determined. The results of this characterization will be presented with emphasis on geophysical testing and seismic survey. These results are also being used to conduct reservoir

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

    NASA Astrophysics Data System (ADS)

    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

  5. Geophysical characterization of buried active faults: the Concud Fault (Iberian Chain, NE Spain)

    NASA Astrophysics Data System (ADS)

    Pueyo Anchuela, Óscar; Lafuente, Paloma; Arlegui, Luis; Liesa, Carlos L.; Simón, José L.

    2016-11-01

    The Concud Fault is a 14-km-long active fault that extends close to Teruel, a city with about 35,000 inhabitants in the Iberian Range (NE Spain). It shows evidence of recurrent activity during Late Pleistocene time, posing a significant seismic hazard in an area of moderate-to-low tectonic rates. A geophysical survey was carried out along the mapped trace of the southern branch of the Concud Fault to evaluate the geophysical signature from the fault and the location of paleoseismic trenches. The survey identified a lineation of inverse magnetic dipoles at residual and vertical magnetic gradient, a local increase in apparent conductivity, and interruptions of the underground sediment structure along GPR profiles. The origin of these anomalies is due to lateral contrast between both fault blocks and the geophysical signature of Quaternary materials located above and directly south of the fault. The spatial distribution of anomalies was successfully used to locate suitable trench sites and to map non-exposed segments of the fault. The geophysical anomalies are related to the sedimentological characteristics and permeability differences of the deposits and to deformation related to fault activity. The results illustrate the usefulness of geophysics to detect and map non-exposed faults in areas of moderate-to-low tectonic activity where faults are often covered by recent pediments that obscure geological evidence of the most recent earthquakes. The results also highlight the importance of applying multiple geophysical techniques in defining the location of buried faults.

  6. SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT

    SciTech Connect

    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.

  7. Joint Hydrological-Geophysical Inversion for Soil StructureIdentification

    SciTech Connect

    Finsterle, Stefan; Kowalsky, Michael B.

    2006-05-01

    Reliable prediction of subsurface flow and contaminant transport depends on the accuracy with which the values and spatial distribution of process-relevant model parameters can be identified. Successful characterization methods for complex soil systems are based on (1) an adequate parameterization of the subsurface, capable of capturing both random and structured aspects of the heterogeneous system, and (2) site-specific data that are sufficiently sensitive to the processes of interest. We present a stochastic approach where the high-resolution imaging capability of geophysical methods is combined with the process-specific information obtained from the inversion of hydrological data. Geostatistical concepts are employed as a flexible means to describe and characterize subsurface structures. The key features of the proposed approach are (1) the joint inversion of geophysical and hydrological raw data, avoiding the intermediate step of creating a (non-unique and potentially biased) tomogram of geophysical properties, (2) the concurrent estimation of hydrological and petrophysical parameters in addition to (3) the determination of geostatistical parameters from the joint inversion of hydrological and geophysical data; this approach is fundamentally different from inference of geostatistical parameters from an analysis of spatially distributed property data. The approach has been implemented into the iTOUGH2 inversion code and is demonstrated for the joint use of synthetic time-lapse ground-penetrating radar (GPR) travel times and hydrological data collected during a simulated ponded infiltration experiment at a highly heterogeneous site.

  8. Development Paths in Archaeological Surveying

    NASA Astrophysics Data System (ADS)

    Tabbagh, A.

    2005-05-01

    Geophysical surveys of archaeological sites began in 1938, when an electrical survey was performed at the historical site of Williamsburg (Virginia, USA). Its full development, however, has been achieved by several European teams, which have continuously worked on it since the fifties. Geophysical survey is one step of archaeological site reconnaissance, which comprises many other non-invasive techniques such as document studies, field walking, air photo interpretation...Nevertheless solely geophysical techniques allow a direct exploration of the underground itself over a significant depth of investigation. Several physical properties can be measured to detect and map archaeological features and/or remains but electrical resistivity and magnetisation has been commonly used for fifty years and dielectric permittivity more recently. The major path of the technical evolution was to increase both the speed of the survey and the size of the area by using short measurement duration (less than 0.1 s) and to incorporate mechanical systems that allow the continuous pulling of the sensors on the field. Magnetic measurements are thus achieved either by fluxgate or optically pumped sensors, while electrical measurements are achieved by mobile multi-pole systems simultaneously over two or three different depths. In such surveys the mesh grid is 1 x 1 m or 0.5 x 0.5 m. Another aim is to limit the size of the surveyed area but to increase the geometrical resolution by using ground penetrating radars (GPR) with a very fine mesh (0.2 x 0.2 m) and by processing the data by `time slices' which allow to follow precisely the extension in depth of the different features. In addition for magnetic features, the simultaneous inversion of magnetic field and susceptibility (and soon viscosity) measurements using linear filtering allows the differentiation among the types of magnetization and allows for an improved determination of the depths of magnetic property contrasts. By considering the

  9. Geophysical Exploration of the Red Rocks Canyon Landfill in Colorado Springs, Colorado

    NASA Astrophysics Data System (ADS)

    Calhoun, N.; Morin, C.; Gy250, S.; Bank, C.

    2005-05-01

    Our introductory geophysics class conducted a survey of the Red Rocks Canyon landfill to determine its boundaries, depth, type of fill, and groundwater runoff patterns. In the 1970s and 1980s the canyon was filled with domestic waste, and has recently been acquired by the city to extend an existing park. Our results in general portray a heterogenous subsurface and reveal that the landfill likely contains many metallic objects. More specifically we found the following: A negative Bouguer anomaly across the landfill matches a model for a ~25 m thick fill. Resistivity is much lower on the landfill than off, but we could not confirm our hypothesis that the landfill drains water through the north end of the canyon. Our seismic data are inconclusive, we think that our assumption of a planar bottom and seismically homogenous fill is violated. The magnetic data show on average higher total values, large (>1,000 nT) variations and high magnetic gradients on the landfill; because this method is fast and very clearly maps the landfill boundaries we propose a magnetic survey to detect possible unregistered dumps outside the mapped boundaries of the landfill. Measuring ground conductivity utilizing an electromagnetic survey produces significantly higher values on the landfill than off. Additionally, directional anisotropies match the direction of the strike of the geological formations adjacent to the landfill and are more randomly oriented on the landfill.

  10. Remote sensing-a geophysical perspective.

    USGS Publications Warehouse

    Watson, K.

    1985-01-01

    In this review of developments in the field of remote sensing from a geophysical perspective, the subject is limited to the electromagnetic spectrum from 0.4 mu m to 25cm. Three broad energy categories are covered: solar reflected, thermal infrared, and microwave.-from Authorremote sensing electromagnetic spectrum solar reflected thermal infrared microwave geophysics

  11. Successful educational geophysics field program expands

    NASA Astrophysics Data System (ADS)

    The Summer of Applied Geophysical Experience (SAGE), a program that gives students an opportunity to apply a variety of modern geophysical methods in a challenging geologic environment, has expanded.A 2-year grant awarded in 1993 by the National Science Foundation's Research Experiences for Undergraduate's (REU) initiative allowed the program to include fourteen U.S. undergraduate students last summer.

  12. Agricultural Geophysics: Past, present, and future

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Celebrating the physics in geophysics

    NASA Astrophysics Data System (ADS)

    Davis, Anthony B.; Sornette, Didier

    The United Nations' Educational, Scientific and Cultural Organization (UNESCO) declared 2005 the “World Year of Physics” in celebration of the centennial of Einstein's annus mirabilis when, as junior clerk at the Swiss Patent Office in Berne, he published three papers that changed physics forever by (1) introducing Special Relativity and demonstrating the equivalence of mass and energy (E = mc2), (2) explaining the photoelectric effect with Planck's then-still-new-and-controversial concept of light quanta (E = hv), and (3) investigating the macroscopic phenomenon of Brownian motion using Boltzmann's molecular dynamics (E = kT), still far from fully accepted at the time.The celebration of Einstein's work in physics inspires the reflection on the status of geophysics and its relationship with physics, in particular with respect to great discoveries.

  14. Strainmeters and tiltmeters in geophysics

    NASA Technical Reports Server (NTRS)

    Goulty, N. R.

    1976-01-01

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

  15. Fractals in geology and geophysics

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald L.

    1989-01-01

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

  16. Satellite Relaying of Geophysical Data

    NASA Technical Reports Server (NTRS)

    Allenby, R. J.

    1977-01-01

    Data Collection Platforms (DCPs) for transmitting surface data to an orbiting satellite for relaying to a central data distribution center are being used in a number of geophysical applications. "Off-the-shelf" DCP's, transmitting through Landsat or GOES satellites, are fully capable of relaying data from low-data-rate instruments, such as tiltmeters or tide gauges. In cooperation with the Lamont-Doherty Geological Observatory, Goddard has successfully installed DCP systems on a tide gauge and tiltmeter array on Anegada, British Virgin Islands. Because of the high-data-rate requirements, a practical relay system capable of handling seismic information is not yet available. Such a system could become the basis of an operational hazard prediction system for reducing losses due to major natural catastrophies such as earthquakes, volcanic eruptions, landslides or tsunamis.

  17. Software complex for geophysical data visualization

    NASA Astrophysics Data System (ADS)

    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

  18. In Situ Geophysical Exploration by Humans in Mars Analog Environments

    NASA Technical Reports Server (NTRS)

    Shiro, B. R.; Ferrone, K. L.

    2010-01-01

    We carried out three geophysical experiments in Mars analog environments in order to better understand the challenges future astronauts will face when conducting similar surveys on Mars or the Moon. The experiments included a passive seismometer deployment and a time-domain electromagnetic survey at the Flashline Mars Arctic Research Station (FMARS) on Devon Island, Canada and a seismic refraction survey in southeastern Utah at the Mars Desert Research Station (MDRS). FMARS is located on the rim of the 23 Ma Haughton Crater in a polar desert environment. MDRS is located in an area with sedimentary plateaus and canyons of Jurassic to Cretaceous age. Both facilities were built by The Mars Society to help develop key knowledge about human Mars exploration. Crews of six spend 2-4 weeks in the habitats and conduct eld research on simulated extravehicular activities (EVAs) wearing mock spacesuits. The work reported here was conducted in July 2009 at FMARS and February 2010 at MDRS.

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

    NASA Astrophysics Data System (ADS)

    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

  20. Extracting Independent Local Oscillatory Geophysical Signals by Geodetic Tropospheric Delay

    NASA Technical Reports Server (NTRS)

    Botai, O. J.; Combrinck, L.; Sivakumar, V.; Schuh, H.; Bohm, J.

    2010-01-01

    Zenith Tropospheric Delay (ZTD) due to water vapor derived from space geodetic techniques and numerical weather prediction simulated-reanalysis data exhibits non-linear and non-stationary properties akin to those in the crucial geophysical signals of interest to the research community. These time series, once decomposed into additive (and stochastic) components, have information about the long term global change (the trend) and other interpretable (quasi-) periodic components such as seasonal cycles and noise. Such stochastic component(s) could be a function that exhibits at most one extremum within a data span or a monotonic function within a certain temporal span. In this contribution, we examine the use of the combined Ensemble Empirical Mode Decomposition (EEMD) and Independent Component Analysis (ICA): the EEMD-ICA algorithm to extract the independent local oscillatory stochastic components in the tropospheric delay derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) over six geodetic sites (HartRAO, Hobart26, Wettzell, Gilcreek, Westford, and Tsukub32). The proposed methodology allows independent geophysical processes to be extracted and assessed. Analysis of the quality index of the Independent Components (ICs) derived for each cluster of local oscillatory components (also called the Intrinsic Mode Functions (IMFs)) for all the geodetic stations considered in the study demonstrate that they are strongly site dependent. Such strong dependency seems to suggest that the localized geophysical signals embedded in the ZTD over the geodetic sites are not correlated. Further, from the viewpoint of non-linear dynamical systems, four geophysical signals the Quasi-Biennial Oscillation (QBO) index derived from the NCEP/NCAR reanalysis, the Southern Oscillation Index (SOI) anomaly from NCEP, the SIDC monthly Sun Spot Number (SSN), and the Length of Day (LoD) are linked to the extracted signal components from ZTD. Results from the synchronization

  1. HVDC Ground Electrodes - a Source of Geophysical Data

    NASA Astrophysics Data System (ADS)

    Freire, P. F.; Pereira, S. Y.

    2015-12-01

    The HVDC electrode is a component of a High Voltage Direct Current energy transmission system, and is designed to inject into the ground continuous currents up to 3500 A. The typical HVDC ground electrode is a ring of vertical conductors, 1 km wide, buried a few tens of meters.The design of a HVDC electrode is based on extensive geological, geotechnical and geophysical surveys. Geophysical data are usually electrical (VES) and electromagnetic (TEM/MT) acquisitions, for the modeling of the shallow, near-surface and deep layers of the crust. This survey aims, first, the electrode site selection, and then, at the selected site, this data is combined into a single apparent resistivity curve, which is inverted, allowing for the determination of the layered geoelectric crust model. The injection of electrical continuous current in the electrode is then simulated, with the geoelectric crust model, for the determination of the soil surface potential profile (which is usually asymmetric for different directions, due to non-1D geoelectric models).For the commissioning of a HVDC electrode, field measurements are done, such as electrode grounding resistance, soil surface potentials and metal-to-soil potentials at specific structures (buried pipelines, for instance).The geophysical data acquired during the design phase is a set of data completely independent from the electrical data acquired during the electrode commissioning phase, and both are correlated by the geoelectric model. It happens, therefore, that the geoelectric model can be calibrated based on the electrical data, with the correction of static shifts and other adjustments.This paper suggests that the commissioning of HVDC systems should be associated to a research & development program, with a university or foundation. The idea is to enjoy the opportunity of a more complete field survey, with the acquisition of a wide set of data for a better geological characterization of the area where the electrode was built.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Application of geophysical methods for environmental control in mining areas

    SciTech Connect

    Mueller, K.; Muellerova, J.; Hofrichterova, L.

    1994-12-31

    In areas affected by mining operations, a variety of methods ar necessary to acquire information for making decisions related to environmental protection. Of great importance are geophysical methods to collect data about: seismic activity and seismic hazard in the area of interest; radon risk; damage to rock massif resulting from mining operations and development of subsidence depression as mining advances; inhomogeneities in compactness of gangue fills and defects in dams and roadbeds; and hydrodynamic changes and contamination of groundwater. The importance of geophysical methods has increased recently, particularly as applied to monitoring or to the repeatable measurement-variant on fixed points. In the Ostrava-Karvina Coal Basin, a seismic station of the first range OKP was built in 1980. Between 1986 and 1990, the regional diagnostic polygon was established, involving 10 three-component stations uniformly distributed throughout the Ostrava-Karvina Basin that allows seismic activity--both natural and, particularly, that induced by mining operations--to be monitored continuously. Analysis of seismic events related to the advance of mining and to engineering and geological conditions enabled researchers to develop a seismic hazard map for surface facilities. This map is useful for design purposes and for making decisions related to maintenance and damages. Emanation measurements, together with other geophysical methods (e.g., resistivity, seismic, acoustic, and thermic measurements), are utilized to determine stability conditions in the area and to observe development of subsidence depressions and slope deformations. Some of the results from these surveys are given.

  4. Geophysics: Building E5440 decommissioning, Aberdeen Proving Ground

    SciTech Connect

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

    1992-11-01

    Building E5440 was one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The results show several complex geophysical signatures. Isolated, one-point, magnetic anomalies surrounding the building may be associated with construction fill. A 10-ft-wide band of strongly magnetic positive anomalies bordering the north side of the building obliterates small magnetic sources that might otherwise be seen. A prominent magnetic nose'' extending northward from this band toward a standpipe at 100N,63E may be connected to an underground tank. The southeast corner of the site is underlain by a rectangular, magnetized source associated with strong radar images. A magnetic lineament extending south from the anomaly may be caused by a buried pipe; the anomaly itself may be caused by subsurface equipment associated with a manhole or utility access pit. A 2,500-gamma, positive magnetic anomaly centered at 0N,20E, which is also the location of a 12 [Omega]-m resistivity minimum, may be caused by a buried vault. It appears on radar imaging as a strong reflector.

  5. Applied geophysical techniques to evaluate earth dams and foundations

    NASA Astrophysics Data System (ADS)

    Llopis, Jose L.; Sharp, Michael K.; Butler, Dwain K.; Yule, Donald E.

    1995-05-01

    Mill Creek Dam, near Walla Walla, Washington has experienced anomalous seepage since its first filling in 1941. Various attempts to abate and control the seepage, including construction of a concrete wall, have not been completely successful. Construction of the cutoff wall reduced the seepage by about 30 percent, from 33 cubic feet per second to 22 cubic feet per second, and downstream saturated farmland was reduced by 56 percent. However, there are indications of increased seepage pressures in a conglomerate formation in the right abutment. A comprehensive, integrated geophysics investigation of the right abutment area of the dam was conducted to detect and map anomalous conditions and assist in the evaluation of remedial measures. The geophysics program consisted of microgravity, ground penetrating radar, seismic reflection, electromagnetic conductivity, and electrical resistivity surveying. Results of the program indicate anomalous conditions extending from the reservoir area through the right abutment. The aspects of the program planning leading to technique selection and field procedures are emphasized, as well as the role of different geophysical techniques in defining the nature of anomalous condition.

  6. Forward modeling of geophysical electromagnetic methods using Comsol

    NASA Astrophysics Data System (ADS)

    Butler, S. L.; Zhang, Z.

    2016-02-01

    In geophysical electromagnetic methods, time-varying magnetic fields are measured at Earth's surface that are produced by electrical currents inside the Earth in order to constrain subsurface conductivity and geological structure. These methods are widely used for mineral exploration and environmental investigations, and are increasingly being used in hydrocarbon exploration as well. Forward modeling of exploration geophysics methods is useful for the purpose of survey planning, for understanding the method, especially for students, and as part of an iteration process in inverting measured data. Modeling electromagnetic methods remains an area of active research. In most geophysical methods, the electromagnetic frequency is sufficiently low that the wavelength of the radiation is much larger than the area of interest. As such, the quasi-static approximation is valid. Comsol Multiphysics' AC/DC module solves Maxwell's equations in the quasi-static approximation and in this contribution, we will show examples of its use in modeling magnetometric resistivity (MMR), very low frequency (VLF) techniques, as well as frequency and time-domain induction-based electromagnetic techniques. Solutions are compared with benchmarks from the literature.

  7. Results of investigation at the Ahuachapan Geothermal Field, El Salvador. Part 2, Electrical-methods geophysics: Final report

    SciTech Connect

    Fink, J.B.

    1990-04-01

    The Ahuachapan Geothermal Field (AGF) is a 95 megawatt geothemal-sourced power-plant operated by the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) of El Salvador. During the past decade, as part of an effort to increase in situ thermal reserves in order to realize the full generation capacity of the AGF, extensive surface geophysical coverage has been obtained over the AGF and the prospective Chipilapa area to the east. The geophysical surveys were performed to determine physical property characteristics of the known reservoir and then to search for similar characteristics in the Chipilapa area. A secondary objective was to evaluate the surface recharge area in the highlands to the south of the AGF. The principal surface electrical geophysical methods used during this period were DC resistivity and magnetotellurics. Three available data sets have been reinterpreted using drillhole control to help form geophysical models of the area. The geophysical models are compared with the geologic interpretations.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  9. EDITORIAL: The interface between geophysics and engineering

    NASA Astrophysics Data System (ADS)

    2004-03-01

    Journal of Geophysics and Engineering (JGE) aims to publicize and promote research and developments in geophysics and in related areas of engineering. As stated in the journal scope, JGE is positioned to bridge the gap between earth physics and geo-engineering, where it reflects a growing trend in both industry and academia. JGE covers those aspects of engineering that bear closely on geophysics or on the targets and problems that geophysics addresses. Typically this will be engineering focused on the subsurface, particularly petroleum engineering, rock mechanics, geophysical software engineering, drilling technology, remote sensing, instrumentation and sensor design. There is a trend, visible throughout academia, for rapid expansion in cross-disciplinary, multi-disciplinary and inter-disciplinary working. Many of the most important and exciting problems and advances are being made at the boundaries between traditional subject areas and, increasingly, techniques from one discipline are finding applications in others. There is a corresponding increasing requirement for researchers to be aware of developments in adjacent areas and for papers published in one area to be readily accessible, both in terms of location and language, to those in others. One such area that is expanding rapidly is that at the interface between geophysics and engineering. There are three principal developments. Geophysics, and especially applied geophysics, is increasingly constrained by the limits of technology, particularly computing technology. Consequently, major advances in geophysics are often predicated upon major developments in engineering and many research geophysicists are working in multi-disciplinary teams with engineers. Engineering problems relevant to the sub-surface are increasingly looking to advances in geophysics to provide part of the solution. Engineering systems, for example, for tunnel boring or petroleum reservoir management, are using high-resolution geophysical

  10. Satellite gravity gradient grids for geophysics

    PubMed Central

    Bouman, Johannes; Ebbing, Jörg; Fuchs, Martin; Sebera, Josef; Lieb, Verena; Szwillus, Wolfgang; Haagmans, Roger; Novak, Pavel

    2016-01-01

    The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite aimed at determining the Earth’s mean gravity field. GOCE delivered gravity gradients containing directional information, which are complicated to use because of their error characteristics and because they are given in a rotating instrument frame indirectly related to the Earth. We compute gravity gradients in grids at 225 km and 255 km altitude above the reference ellipsoid corresponding to the GOCE nominal and lower orbit phases respectively, and find that the grids may contain additional high-frequency content compared with GOCE-based global models. We discuss the gradient sensitivity for crustal depth slices using a 3D lithospheric model of the North-East Atlantic region, which shows that the depth sensitivity differs from gradient to gradient. In addition, the relative signal power for the individual gradient component changes comparing the 225 km and 255 km grids, implying that using all components at different heights reduces parameter uncertainties in geophysical modelling. Furthermore, since gravity gradients contain complementary information to gravity, we foresee the use of the grids in a wide range of applications from lithospheric modelling to studies on dynamic topography, and glacial isostatic adjustment, to bedrock geometry determination under ice sheets. PMID:26864314

  11. Satellite gravity gradient grids for geophysics.

    PubMed

    Bouman, Johannes; Ebbing, Jörg; Fuchs, Martin; Sebera, Josef; Lieb, Verena; Szwillus, Wolfgang; Haagmans, Roger; Novak, Pavel

    2016-02-11

    The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite aimed at determining the Earth's mean gravity field. GOCE delivered gravity gradients containing directional information, which are complicated to use because of their error characteristics and because they are given in a rotating instrument frame indirectly related to the Earth. We compute gravity gradients in grids at 225 km and 255 km altitude above the reference ellipsoid corresponding to the GOCE nominal and lower orbit phases respectively, and find that the grids may contain additional high-frequency content compared with GOCE-based global models. We discuss the gradient sensitivity for crustal depth slices using a 3D lithospheric model of the North-East Atlantic region, which shows that the depth sensitivity differs from gradient to gradient. In addition, the relative signal power for the individual gradient component changes comparing the 225 km and 255 km grids, implying that using all components at different heights reduces parameter uncertainties in geophysical modelling. Furthermore, since gravity gradients contain complementary information to gravity, we foresee the use of the grids in a wide range of applications from lithospheric modelling to studies on dynamic topography, and glacial isostatic adjustment, to bedrock geometry determination under ice sheets.

  12. Geophysical investigations of well fields to characterize fractured-bedrock aquifers in southern New Hampshire

    USGS Publications Warehouse

    Degnan, James R.; Moore, Richard Bridge; Mack, Thomas J.

    2001-01-01

    Bedrock-fracture zones near high-yield bedrock wells in southern New Hampshire well fields were located and characterized using seven surface and six borehole geophysical survey methods. Detailed surveys of six sites with various methods provide an opportunity to integrate and compare survey results. Borehole geophysical surveys were conducted at three of the sites to confirm subsurface features. Hydrogeologic settings, including a variety of bedrock and surface geologic materials, were sought to gain an insight into the usefulness of the methods in varied terrains. Results from 15 survey lines, 8 arrays, and 3 boreholes were processed and interpreted from the 6 sites. The surface geophysical methods used provided physical properties of fractured bedrock. Seismic refraction and ground-penetrating radar (GPR) primarily were used to characterize the overburden materials, but in a few cases indicated bedrock-fracture zones. Magnetometer surveys were used to obtain background information about the bedrock to compare with other results, and to search for magnetic lows, which may result from weathered fractured rock. Electromagnetic terrain conductivity surveys (EM) and very-low-frequency electromagnetic surveys (VLF) were used as rapid reconnaissance techniques with the primary purpose of identifying electrical anomalies, indicating potential fracture zones in bedrock. Direct-current (dc) resistivity methods were used to gather detailed subsurface information about fracture depth and orientation. Two-dimensional (2-D) dc-resistivity surveys using dipole-dipole and Schlumberger arrays located and characterized the overburden, bedrock, and bedrock-fracture zones through analysis of data inversions. Azimuthal square array dc-resistivity survey results indicated orientations of conductive steep-dipping bedrock-fracture zones that were located and characterized by previously applied geophysical methods. Various available data sets were used for site selection

  13. Geophysical log analysis of selected test and residential wells at the Shenandoah Road National Superfund Site, East Fishkill, Dutchess County, New York

    USGS Publications Warehouse

    Reynolds, Richard J.; Anderson, J. Alton; Williams, John H.

    2015-01-01

    The geophysical logs and their analyses are available for display and download from the U.S. Geological Survey, New York Water Science Center, online geophysical log archive (http://ny.water.usgs.gov/maps/geologs/) in LAS (Log ASCII Standard), PDF, and WellCad formats.

  14. Geophysical anatomy of counter-slope scarps in sedimentary flysch rocks (Outer Western Carpathians)

    NASA Astrophysics Data System (ADS)

    Tábořík, P.; Lenart, J.; Blecha, V.; Vilhelm, J.; Turský, O.

    2017-01-01

    A multidisciplinary geophysical survey, consisting of electrical resistivity tomography (ERT), ground penetrating radar (GPR), shallow seismic refraction (SSR) and gravity survey (GS), was used to investigate the counter-slope scarps, one of the typical manifestations of the relaxed zones of rock massifs, and the possible initial stages of deep-seated landslides (DSLs). Two upper parts of the extensive DSLs within the Moravskoslezské Beskydy Mountains (Outer Western Carpathians - OWC) built by the sedimentary flysch rock were chosen as the testing sites. A combined geophysical survey on the flysch rocks was performed on both localities to enhance our present findings. The survey revealed that the ERT is able to reliably detect underground discontinuities, which are manifested at the ground surface by one of the typical landforms (tension cracks, trenches, pseudokarst sinkholes, double-crested ridges and counter-slope scarps). Previous studies suggested that bedrock discontinuities should be depicted by high-resistivity features within ERT surveying. According to SSR and GS, expected zones of weakened rock massif were not confirmed directly underneath the superficial landforms, but they were shifted. Based on the SSR and GS measurements, the depicted high-contrast transitions between high- and low-resistivity domains within the ERT profiles were newly identified as possible manifestation of bedrock discontinuities. The results of GPR measurements give only limited information on the sedimentary flysch rocks, due to shallow penetrating depth and locally strong signal attenuation. The combined results of multidisciplinary geophysical surveying confirmed an importance of employing more than one geophysical technique for integrated interpretations of measured data. Integrated interpretations of the measured geophysical data provided a new insight into massif disintegration and the geomorphic origin of the landforms related to the DSL.

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

    NASA Astrophysics Data System (ADS)

    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

  16. Pavement testing by integrated geophysical methods: Feasibility, resolution and diagnostic potential

    NASA Astrophysics Data System (ADS)

    Orlando, Luciana; Cardarelli, Ettore; Cercato, Michele; De Donno, Giorgio; Di Giambattista, Luca

    2017-01-01

    This work is focused on the assessment of the diagnostic potential of several geophysical methods when applied to the investigation of a rigid airport pavement. The potential and limit of each technique are evaluated as well as the added value deriving from their integration. Firstly, we reconstruct a high-resolution image of the pavement by a large electromagnetic and georadar screening. An advanced processing of georadar data, implemented through the picking of the arrival times of reflections for each profile, provides a quantitative estimation of the deviation between the design and the as-built thickness of layers. Additionally, electrical tomography has been applied to unequivocally identify the anomalous zones, where higher values of resistivity would be associated to porous zones that are prone to degradation and failure. The seismic tomographic survey had the additional purpose to recover the mechanical properties of the pavement in terms of both P- and S-waves and consequently of elastic constants (Poisson's ratio), whose values were consistent with those recovered in literature. The anomalies detected by each technique are consistent in their indications and they can be correlated to failure phenomena occurring at layer interfaces within the pavement structure or to unexpected variations of the layer thicknesses. The cost-effective geophysical campaign has validated the four-layered system deduced from the original design and has been used to reconstruct a high-resolution map of the pavement in order to discriminate fractures, crack-prone areas or areas where the as-built differs from the original design.

  17. Faculty receives Excellence in Geophysical Education Award

    NASA Astrophysics Data System (ADS)

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

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

  18. Geochemistry and geophysics field maps used during the USGS 2011 field season in southwest Alaska

    USGS Publications Warehouse

    Giles, Stuart A.

    2013-01-01

    The US Geological Survey (USGS) has been studying a variety of geochemical and geophyscial assessment techniques for concealed mineral deposits. The 2011 field season for this project took place in southwest Alaska, northeast of Bristol Bay between Dillingham and Iliamna Lake. Four maps were created for the geochemistry and geophysics teams to use during field activities.

  19. Fundamentals of Geophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    McWilliams, James C.

    2006-07-01

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

  20. Feds fund geophysical energy research

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Amid the current confusion surrounding the pending fate of the United States Department of Energy (President Reagan proposed a plan to ‘dismantle’ it), a rather large program, sometimes called ‘Physical Research in the Geosciences,’ survives in financially healthy condition. According to the recent report ‘Summary Outline of DOE Geoscience and Geoscience-Related Research (DOE/ER-0120, Feb. 1982), the amount of funding granted to university researchers for the current fiscal year is $16 million.In a procedure similar to other federal government unsolicited grant research proplate grams, funds are awarded to successful university applicants on the basis of research proposals. An interesting note is that apparently because of the uncertainties surrounding the futures of several federal programs, including the DOE, some researchers have assumed, incorrectly, that many sources of research funding may be discontinued. Meanwhile, program directors of the National Science Foundation have told Eos that their programs are experiencing a large increase in research proposals because investigators are apparently seeking other sources of funding. As the Office of Management Budget request for fiscal year 1983 stands at the present time, funding for geophysical energy research will be increased substantially under the Office of Basic Energy Sciences.

  1. SimPEG: An open-source framework for geophysical simulations and inverse problems

    NASA Astrophysics Data System (ADS)

    Cockett, R.; Kang, S.; Heagy, L.

    2014-12-01

    Geophysical surveys are powerful tools for obtaining information about the subsurface. Inverse modelling provides a mathematical framework for constructing a model of physical property distributions that are consistent with the data collected by these surveys. The geosciences are increasingly moving towards the integration of geological, geophysical, and hydrological information to better characterize the subsurface. This integration must span disciplines and is not only challenging scientifically, but the inconsistencies between conventions often makes implementations complicated, non-reproducible, or inefficient. We have developed an open source software package for Simulation and Parameter Estimation in Geophysics (SimPEG), which provides a generalized framework for solving geophysical forward and inverse problems. SimPEG is written entirely in Python with minimal dependencies in the hopes that it can be used both as a research tool and for education. SimPEG includes finite volume discretizations on structured and unstructured meshes, interfaces to standard numerical solver packages, convex optimization algorithms, model parameterizations, and tailored visualization routines. The framework is modular and object-oriented, which promotes real time experimentation and combination of geophysical problems and inversion methodologies. In this presentation, we will highlight a few geophysical examples, including direct-current resistivity and electromagnetics, and discuss some of the challenges and successes we encountered in developing a flexible and extensible framework. Throughout development of SimPEG we have focused on simplicity, usability, documentation, and extensive testing. By embracing a fully open source development paradigm, we hope to encourage reproducible research, cooperation, and communication to help tackle some of the inherently multidisciplinary problems that face integrated geophysical methods.

  2. Geophysical tomography. January 1976-July 1988 (Citations from the NTIS data base). Report for January 1976-July 1988

    SciTech Connect

    Not Available

    1988-07-01

    This bibliography contains citations concerning image reconstruction of geologic properties, internal geometry of rock masses, and mapping of fractures using geophysical tomography. Applications include site characterization, ground-water movement, structural geology, well logging, oil-field recovery processes, underground waste disposal, and geophysical surveys. The citations on techniques include algorithms and software to perform tomographic image reconstruction. (Contains 74 citations fully indexed and including a title list.)

  3. Ground Gravity, Magnetic and Electromagnetic Surveys on a Crater on Basalt of Bajada del Diablo Astrobleme-Strewn Field

    NASA Astrophysics Data System (ADS)

    Acevedo, R. D.; Prezzi, C.; Orgeira, M. J.; Rocca, M.; Martínez, O.; Ponce, J. F.; Corbella, H.; Rabassa, J.; González-Guillot, M.; Subías, I.

    2014-09-01

    With the aim of further investigate the circular structures from Bajada del Diablo, we carried out geophysics surveys and we conclude that the geophysical features could be satisfactorily explained assuming an extra-terrestrial projectile impact.

  4. Geo-Seas - a pan-European infrastructure for the management of marine geological and geophysical data.

    NASA Astrophysics Data System (ADS)

    Glaves, Helen; Graham, Colin

    2010-05-01

    countries. This makes the direct use of primary data in an integrated way very difficult and also hampers use of the data sets in a harmonised way to produce multidisciplinary data products and services. To ensure interoperability with other marine environmental data types Geo-Seas ISO19115 metadata, OGC and GeoSciML standards will be used as the basis for the metadata profiles for the geological and geophysical data. This will be largely achieved by modifying the SeaDataNet metadata standard profile (Common Data Index or CDI), which is itself based upon the ISO19115 standard, to accommodate the requirements of the Geo-Seas project. The overall objective of Geo-Seas project is to build and deploy a unified marine geoscientific data infrastructure within Europe which will in effect provide a data grid for the sharing of marine geological and geophysical data. This will result in a major improvement in the locating, accessing and delivery of federated marine geological and geophysical data and data products from national geological surveys and research institutes across Europe. There is an emphasis on interoperability both with other disciplines as well as with other key framework projects including the European Marine Observation and Data Network (EMODNet) and One Geology - Europe. In addition, a key objective of the Geo-Seas project is to underpin European directives such as INSPIRE as well as recent framework programmes on both the global and European scale, for example Global Earth Observation System of Systems (GEOSS) and Global Monitoring for Environment and Security (GMES), all of which are intended to encourage the exchange of data and information. Geo-Seas consortium partners: NERC-BGS (United Kingdom), NERC-BODC (United Kingdom), NERC-NOCS (United Kingdom), MARIS (Netherlands), IFREMER (France), BRGM (France), TNO (Netherlands), BSH (Germany), IGME (Spain), INETI (Portugal), IGME (Greece), GSI (Ireland), BGR (Germany), OGS (Italy), GEUS (Denmark), NGU (Norway), PGI

  5. Geophysical experiments to image the shallow internal structure and the moisture distribution of a mine waste rock pile

    NASA Astrophysics Data System (ADS)

    Poisson, Jérôme; Chouteau, Michel; Aubertin, Michel; Campos, Daniel

    2009-02-01

    Several field surveys of a waste rock pile were carried out during the summers of 2002 and 2003 using ground-penetrating radar, electromagnetic conductivity and DC resistivity imaging. The waste rock deposit is prone to generate acid mine drainage (AMD) due to the oxidation of sulphidic minerals. One of the most critical factors that lead to the production of AMD is unsaturated water flow and the ensuing moisture distribution in the waste rock. This geophysical characterization study, performed over a 30 m × 30 m test zone, was designed to image the internal structure controlling the water flux at shallow depth. The subsurface was found to consist of three zones for the first 6 m of the pile, mainly based on electrical resistivities: a thin superficial conductive material, an intermediate 2 to 3 m thick highly resistive zone, and a lower, more conductive medium. With the help of hydrogeological tests, chemical analyses and two 2.5 m-deep trenches, it is shown that the two conductive zones are correlated with fine-grained waste rock and the resistive zone correlates with a coarser material. In the two deeper zones, the contact between the two types of waste rock is typically highlighted by a sharp resistive/conductive boundary. An increase of conductance in the relatively thin upper layer towards the edge of the pile appears to be caused by an increase in thickness of the fine-grained material. Additional geophysical surveys carried out on a profile along the flank of the upper bench of the pile show that the main features of the internal structure are sub-parallel to the slope, at least for the first 3 m in depth. The data also show an increase in resistivity from the top to bottom of the slope, in accordance with expected particle segregation, from fine-grained material at the top to coarser material at the bottom. Wide-angle reflection GPR monitoring during large scale infiltration tests seems to indicate preferential flow paths towards the direction of coarser

  6. Geophex airborne unmanned survey system

    SciTech Connect

    Won, I.J.; Taylor, D.W.A.

    1995-03-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected.

  7. Physicist + Geologist points to Geophysics Course

    ERIC Educational Resources Information Center

    Julian, Glenn M.; Stueber, Alan M.

    1974-01-01

    A two-quarter introductory course in geophysics at the advanced undergraduate/beginning graduate level is described. An outline of course content is provided, and mechanics of instruction are discussed. (DT)

  8. Tabletop Models for Electrical and Electromagnetic Geophysics.

    ERIC Educational Resources Information Center

    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)

  9. Refining 3D Earth models by unifying geological and geophysical information on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Lelièvre, P. G.; Carter-McAuslan, A.; Tycholiz, C.; Farquharson, C. G.; Hurich, C. A.

    2012-04-01

    Earth models used for mineral exploration or other subsurface investigations should be consistent with all available geological and geophysical information. Geophysical inversion provides the means to integrate geological information, geophysical survey data, and physical property measurements taken on rock samples. Incorporation of geological information into inversions is always an iterative process. One begins with the geologists' best guess about the Earth (i.e. the geological model) and the models recovered from geophysical inversion may indicate that the geological model should be changed slightly prior to the next iteration of the procedure. In this way, geological and geophysical data can be combined through inversion and we can move towards the creation of a common Earth model consistent with all the available data. As more information is incorporated, the inherent non-uniqueness of the inverse problem is reduced, yielding a higher potential to resolve deeper features that are less well-constrained by the geophysical data alone. Geological ore deposit models are commonly created during delineation drilling. The accuracy of these models is crucial when used to determine if a deposit is economic. 3D geological Earth models typically comprise wireframe surfaces that represent the geological contacts between different rock units. The contacts may be known at points from down-hole intersections and surface mapping, and can be interpolated between boreholes and extrapolated outwards. Contacts may also be interpreted from seismic traces. Wireframe surfaces, comprising tessellated triangular facets, are sufficiently flexible to allow the representation of arbitrarily complicated geological structures. These surfaces can be honoured exactly within fully unstructured 3D volumetric tetrahedral meshes. In contrast, geophysical forward modelling and inversion algorithms typically work with rectilinear meshes when parameterizing the subsurface because this simplifies

  10. Spiral inertial waves emitted from geophysical vortices

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Özgökmen, Tamay M.

    2016-03-01

    By numerically simulating an initially unstable geophysical vortex, we discover for the first time a special kind of inertial waves, which are emitted in a spiral manner from the vortices; we refer to these waves as spiral inertial waves (SIWs). SIWs appear at small Rossby numbers (0.01 ≤ Ro ≤ 1) according to our parameter sweep experiments; the amplitude, wavelength and frequency of SIWs are sensitive to Rossby numbers. We extend the Lighthill-Ford radiation into inertial waves, and propose an indicator for the emission of inertial waves; this indicator may be adopted into general circulation models to parameterize inertial waves. Additionally, in our tracer releasing experiments, SIWs organize tracers into spirals, and modify the tracer's local rate of change by advecting tracers vertically. Further, the spirals of SIWs resembles some spiral features observed in the ocean and atmosphere, such as spiral ocean eddies and spiral hurricane rainbands; thus, SIWs may offer another mechanism to form spiral eddies and rainbands. Since no density anomaly is required to generate the spirals of SIWs, we infer that the density anomaly, hence the baroclinic or frontal instability, is unlikely to be the key factor in the formation of these spiral features.

  11. Electromagnetic geophysical observation with controlled source

    NASA Astrophysics Data System (ADS)

    Hachay, Olga; Khachay, Oleg

    2016-04-01

    In the paper the new theoretical and methodical approaches are examined for detailed investigations of the structure and state of the geological medium, and its behavior as a dynamic system in reaction to external man-made influences. To solve this problem it is necessary to use geophysical methods that have sufficient resolution and that are built on more complicated models than layered or layered-block models. One of these methods is the electromagnetic induction frequency-geometrical method with controlled sources. Here we consider new approaches using this method for monitoring rock shock media by means of natural experiments and interpretation of the practical results. That method can be used by oil production in mines, where the same events of non stability can occur. The key ideas of twenty first century geophysics from the point of view of geologist academician A.N. Dmitrievskiy [Dmitrievskiy, 2009] are as follows. "The geophysics of the twenty first century is an understanding that the Earth is a self-developing, self-supporting geo-cybernetic system, in which the role of the driving mechanism is played by the field gradients; the evolution of geological processes is a continuous chain of transformations and the interaction of geophysical fields in the litho- hydro- and atmosphere. The use of geophysical principles of a hierarchical quantum of geophysical space, non-linear effects, and the effects of reradiating geophysical fields will allow the creation of a new geophysics. The research, in which earlier only pure geophysical processes and technologies were considered, nowadays tends to include into consideration geophysical-chemical processes and technologies. This transformation will allow us to solve the problems of forecasting geo-objects and geo-processes in previously unavailable geological-technological conditions." The results obtained allow us to make the following conclusions, according to the key ideas of academician A.N. Dmitrievskiy: the rock

  12. Integrated geophysical and chemical study of saline water intrusion.

    PubMed

    Choudhury, Kalpan; Saha, D K

    2004-01-01

    Surface geophysical surveys provide an effective way to image the subsurface and the ground water zone without a large number of observation wells. DC resistivity sounding generally identifies the subsurface formations-the aquifer zone as well as the formations saturated with saline/brackish water. However, the method has serious ambiguities in distinguishing the geological formations of similar resistivities such as saline sand and saline clay, or water quality such as fresh or saline, in a low resistivity formation. In order to minimize the ambiguity and ascertain the efficacy of data integration techniques in ground water and saline contamination studies, a combined geophysical survey and periodic chemical analysis of ground water were carried out employing DC resistivity profiling, resistivity sounding, and shallow seismic refraction methods. By constraining resistivity interpretation with inputs from seismic refraction and chemical analysis, the data integration study proved to be a powerful method for identification of the subsurface formations, ground water zones, the subsurface saline/brackish water zones, and the probable mode and cause of saline water intrusion in an inland aquifer. A case study presented here illustrates these principles. Resistivity sounding alone had earlier failed to identify the different formations in the saline environment. Data integration and resistivity interpretation constrained by water quality analysis led to a new concept of minimum resistivity for ground water-bearing zones, which is the optimum value of resistivity of a subsurface formation in an area below which ground water contained in it is saline/brackish and unsuitable for drinking.

  13. Geophysics: Building E5375 decommissioning, Aberdeen Proving Ground

    SciTech Connect

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

    1992-08-01

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

  14. Geophysics: Building E5282 decommissioning, Aberdeen Proving Ground

    SciTech Connect

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

    1992-08-01

    This report discusses Building E5282 which was one of 10 potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar (GPR), were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. Magnetic surveys identified small, complicated, multiple anomalies west, north, and northeast of the building that may be caused by construction fill. Two underground storage tanks, at the northeast and southeast corners, were identified. A large magnetic anomaly complex east of the building was caused by aboveground pipes and unexploded ordnance fragments scattered at the surface. Electrical resistivity profiling showed a broad, conductive terrain superimposed over magnetic anomalies on the north and west. A broad, high-resistivity, nonmagnetic area centered 25 ft east of the building has an unknown origin, but it may be due to nonconductive organic liquids, construction fill, or a buried concrete slab; GPR imaging showed this area as a highly reflective zone at a depth of about 5 ft. The GPR data also showed a small-diameter pipe oriented north-south located east of the building.

  15. Geophysics: Building E5190 decommissioning, Aberdeen Proving Ground

    SciTech Connect

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

    1992-07-01

    Building E5190 is one of ten potentially contaminated sites in the Canal Creek area of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May 1992. A noninvasive geophysical survey, including the complementary technologies of magnetics, electrical resistivity, and ground-penetrating radar, was conducted around the perimeter as a guide to developing a sampling and monitoring program prior to decommissioning and dismantling the building. The magnetics surveys indicated that multistation, positive magnetic sources are randomly distributed north and west of the building. Two linear trends were noted: one that may outline buried utility lines and another that is produced by a steel-covered trench. The resistivity profiling indicated three conductive zones: one due to increased moisture in a ditch, one associated with buried utility lines, and a third zone associated with the steel-covered trench. Ground-penetrating radar imaging detected two significant anomalies, which were correlated with small-amplitude magnetic anomalies. The objectives of the study -- to detect and locate objects and to characterize a located object were achieved.

  16. A Newly Adopted Helicopter Platform for Geophysical and Remote Sensing

    NASA Astrophysics Data System (ADS)

    Meyer, Uwe

    2014-05-01

    The Federal Institute for Geosciences and Natural Resources in Hannover owns a Sikorsky S-76B helicopter for geophysical and remote sensing airborne surveys. This platform has been completely refurbished and in parts newly designed to be fit for easy installations of complex geophysical instruments underneath, upon and within the helicopter. The airborne platform is equipped with a modern basic navigation equipment consisting of several GNSS antennae, state of the art inertial navigation systems, laser altimeter and video camera systems. Different other modules can be added to the helicopter as a state of the art gamma spectrometer, a laser scanner, airborne gravity meters etc. within the cabin. Moreover, external sensing systems as a photogrammetric camera, infraread camera or optional mulitspectral systems can be installed on the outer skin of the cabin. Different kinds of bird systems towed underneath the helicopter can be hooked up using standard cabling, glas fibres or wireless LAN. Available birds are equipped for frequency domain electromagnetics or gradient magnetics (IPHT Jena & Supracon, Jena). Besides, large georadar systems can be installed as well. The helicopter is able as well to carry TEM-gear or system in development. Main survey targets are groundwater systems, mineral deposits and natural hazards.

  17. SIMPEG: An open source framework for simulation and gradient based parameter estimation in geophysical applications

    NASA Astrophysics Data System (ADS)

    Cockett, Rowan; Kang, Seogi; Heagy, Lindsey J.; Pidlisecky, Adam; Oldenburg, Douglas W.

    2015-12-01

    Inverse modeling is a powerful tool for extracting information about the subsurface from geophysical data. Geophysical inverse problems are inherently multidisciplinary, requiring elements from the relevant physics, numerical simulation, and optimization, as well as knowledge of the geologic setting, and a comprehension of the interplay between all of these elements. The development and advancement of inversion methodologies can be enabled by a framework that supports experimentation, is flexible and extensible, and allows the knowledge generated to be captured and shared. The goal of this paper is to propose a framework that supports many different types of geophysical forward simulations and deterministic inverse problems. Additionally, we provide an open source implementation of this framework in Python called SIMPEG (Simulation and Parameter Estimation in Geophysics,

  18. Coupled thermal and geophysical modelling for monitoring of permafrost

    NASA Astrophysics Data System (ADS)

    Rings, Jörg; Scherler, Martin; Hauck, Christian

    2010-05-01

    weighted according to the degree of agreement between measured and modelled ERT response. A re-sampling routine is used to ensure that, over time, the particles gravitate towards the posterior distributions in state and parameter estimate. To test the approach, modelled and observed ground temperatures were compared at the high-altitude permafrost station on Schilthorn, Berner Oberland/Swiss Alps. First results using automated ERT monitoring data from the PERMOS (Permafrost Monitoring Switzerland) network show a good performance during a 6-month period in spring and summer 2009. Improvements can be achieved by using more sophisticated thermal models and by iterative procedures to determine the (vertically variable) material properties of the subsurface, such as porosity and thermal conductivity. The results were furthermore compared with results from the complex 1-dimensional coupled heat and mass transfer model COUP, which simulates the permafrost evolution without additional incorporation of geophysical subsurface data.

  19. Recommended reference figures for geophysics and geodesy

    NASA Technical Reports Server (NTRS)

    Khan, M. A.; Okeefe, J. A.

    1973-01-01

    Specific reference figures are recommended for consistent use in geophysics and geodesy. The selection of appropriate reference figure for geophysical studies suggests a relationship between the Antarctic negative gravity anomaly and the great shrinkage of the Antarctic ice cap about 4-5 million years ago. The depression of the south polar regions relative to the north polar regions makes the Southern Hemisphere flatter than the Northern Hemisphere, thus producing the third harmonic (pear-shaped) contribution to the earth's figure.

  20. Multiscale geophysical imaging of the critical zone

    NASA Astrophysics Data System (ADS)

    Parsekian, A. D.; Singha, K.; Minsley, B. J.; Holbrook, W. S.; Slater, L.

    2015-03-01

    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.

  1. The remote sensing needs of Arctic geophysics

    NASA Technical Reports Server (NTRS)

    Campbell, W. J.

    1970-01-01

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

  2. Non-Seismic Geophysical Approaches to Monitoring

    SciTech Connect

    Hoversten, G.M.; Gasperikova, Erika

    2004-09-01

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

  3. Geophysical observations at cavity collapse

    NASA Astrophysics Data System (ADS)

    Jousset, Philippe; Bazargan-Sabet, Behrooz; Lebert, François; Bernardie, Séverine; Gourry, Jean-Christophe

    2010-05-01

    In Lorraine region (France) salt layers at about 200 meters depth are exploited by Solvay using solution mining methodology which consists in extracting the salt by dissolution, collapsing the cavern overburden during the exploitation phase and finally reclaiming the landscape by creating a water area. In this process, one of the main challenges for the exploiting company is to control the initial 120-m diameter collapse so as to minimize possible damages. In order to detect potential precursors and understand processes associated with such collapses, a wide series of monitoring techniques including micro seismics, broad-band seismology, hydro-acoustic, electromagnetism, gas probing, automatic leveling, continuous GPS, continuous gravity and borehole extensometry was set-up in the frame of an in-situ study carried out by the "Research Group for the Impact and Safety of Underground Works" (GISOS, France). Equipments were set-up well before the final collapse, giving a unique opportunity to analyze a great deal of information prior to and during the collapse process which has been successfully achieved on February the 13th, 2009 by controlling the cavity internal pressure. In this work, we present the results of data recorded by a network of 3 broadband seismometers, 2 accelerometers, 2 tilt-meters and a continuously gravity meter. We relate the variations of the brine pumping rate with the evolutions of the induced geophysical signals and finally we propose a first mechanical model for describing the controlled collapse. Beyond the studied case, extrapolation of the results obtained might contribute to the understanding of uncontrolled cavity collapses, such as pit-craters or calderas at volcanoes.

  4. Prediction of Geophysical Flow Mobility

    NASA Astrophysics Data System (ADS)

    Cagnoli, B.; Piersanti, A.

    2014-12-01

    The prediction of the mobility of geophysical flows to assess their hazards is one of the main research goals in the earth sciences. Our laboratory experiments and numerical simulations are carried out to understand the effects of grain size and flow volume on the mobility of the centre of mass of dry granular flows of angular rock fragments that have pyroclastic flows and rock avalanches as counterpart in nature. We focus on the centre of mass because it provides information about the intrinsic ability of a flow to dissipate more or less energy as a function of its own features. We show that the grain size and flow volume effects can be expressed by a linear relationship between scaling parameters where the finer the grain size or the smaller the flow volume, the more mobile the centre of mass of the granular flow. The grain size effect is the result of the decrease of particle agitation per unit of flow mass, and thus, the decrease of energy dissipation per unit of travel distance, as grain size decreases. In this sense, flows with different grain sizes are like cars with engines with different fuel efficiencies. The volume effect is the result of the fact that the deposit accretes backward during its formation on a slope change (either gradual or abrupt). We adopt for the numerical simulations a 3D discrete element modeling which confirms the grain size and flow volume effects shown by the laboratory experiments. This confirmation is obtained without prior fine tuning of the parameter values to get the desired output. The numerical simulations reveal also that the larger the initial compaction of the granular mass before release, the more mobile the flow. This behaviour must be taken into account to prevent misinterpretation of laboratory and field data. Discrete element modeling predicts the correct effects of grain size and flow volume because it takes into consideration particle interactions that are responsible for the energy dissipated by the flows.

  5. Geophysics of Small Planetary Bodies

    NASA Technical Reports Server (NTRS)

    Asphaug, Erik I.

    1998-01-01

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

  6. Solar-geophysical data number 499, March 1986, supplement

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This supplement contains the description and explanation of the data in the monthly publication Solar-Geophysical Data, compiled by the National Geophysical Data Center (NGDC) in Boulder, Colo., USA. Solar-Geophysical Data is intended to keep research workers informed on a timely schedule of the major events of solar activity and the associated interplanetary, ionospheric, radio propagation and other geophysical effects.

  7. Combined geophysical investigation for the detection of ancient metallurgical installations near Keratea City, Greece

    NASA Astrophysics Data System (ADS)

    Apostolopoulos, George V.

    2014-05-01

    Archaeological excavation in an area of Lavrio (mining area from ancient times) has revealed ancient metallurgical installations which offer valuable information on this activity at those times. Within this context, a combined geophysical investigation was carried out in a place near Keratea City to find out whether there are additional installations apart from those that have already been revealed in the immediate area. More importantly, the objective was to locate the ancient tanks which provided water to the installations. Archaeological and geological information have helped in the design of the survey. EMI method measuring apparent conductivity was used to cover the whole area of investigation. Conductivity maps in various investigation depths have positioned the tanks and stacked first derivative maps in two directions (the two directions of the revealed walls) show covered walls. The EMI survey has indicated the position of three (3) ERT profiles made with the dipole-dipole array, which presented the ancient tanks with great detail in depth. GPR profiles for the detection of walls were noisy with the coarse material surface layer but the interrelation with ERT and EMI results confirmed the detected features.

  8. Optimizing the design of geophysical experiments: Is it worthwhile?

    NASA Astrophysics Data System (ADS)

    Curtis, Andrew; Maurer, Hansruedi

    Determining the structure, composition, and state of the Earth's subsurface from measured data is the principal task of many geophysical experiments and surveys. Standard procedures involve the recording of appropriate data sets followed by the application of data analysis techniques to extract the desired information. While the importance of new tools for the analysis stage of an experiment is well recognized, much less attention seems to be paid to improving the data acquisition.A measure of the effort allocated to data analysis research relative to that devoted to data acquisition research is presented in Figure 1. Since 1955 there have been more than 10,000 publications on inversion methods alone, but in the same period only 100 papers on experimental design have appeared in journals. Considering that the acquisition component of an experiment defines what information will be contained in the data, and that no amount of data analysis can compensate for the lack of such information, we suggest that greater effort be made to improve survey planning techniques. Furthermore, given that logistical and financial constraints are often stringent and that relationships between geophysical data and model parameters describing the Earths subsurface are generally complicated, optimizing the design of an experiment may be quite challenging. Here we review experimental design procedures that optimize the benefit of a field survey, such that maximum information about the target structures is obtained at minimum cost. We also announce a new Web site and e-mail group set up as a forum for communication on survey design research and application.

  9. Geophysical logging at the Cristex Drum National Priorities List Superfund Site near Oxford, North Carolina

    USGS Publications Warehouse

    Antolino, Dominick J.

    2017-01-01

    The collection of borehole geophysical logs data was conducted by the U.S. Geological Survey South Atlantic Water Science Center in the vicinity of the Cristex Drum National Priorities List Superfund Site near Oxford, North Carolina, during January through March 2016. In an effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants, borehole geophysical log and image data collection, which included the delineation of more than 150 subsurface features (primarily fracture orientations) in 3 open borehole wells.

  10. Geophysical detection of on-site wastewater plumes in the North Carolina Coastal Plain, USA

    NASA Astrophysics Data System (ADS)

    Smith, Matthew

    Nonpoint source pollution (NPS) continues to be the leading cause of water quality degradation in the United States. On-site wastewater systems (OWS) contribute to NPS; however, due to the range of system designs and complexity of the subsurface, OWS contributions to groundwater pollution are not well understood. As the population of coastal North Carolina continues to increase, better methods to locate and characterize wastewater impacted groundwater are needed. Previous studies have demonstrated the ability of non-intrusive geophysical methods to provide high resolution information on various contaminants in different geologic settings. The goals of this study were to evaluate the utility of ground penetrating radar (GPR) and capacitively coupled resistivity (CCR) for detecting OWS components, delineating associated wastewater plumes, and monitoring temporal variations in groundwater quality. Cross-sectional and three dimensional (3D) geophysical surveys were conducted periodically over a one year period (February 2011--January 2012) at two schools utilizing OWS in the lower Neuse River Basin (NRB) in the North Carolina Coastal Plain (NCCP). Cores were collected at both study sites; as well as monthly groundwater depth, temperature, and specific conductivity measurements to better constrain the geophysical interpretations. Additionally, dissolved inorganic nitrogen (DIN) and Cl concentrations were monitored bi-monthly to assess nutrient transport at the sites. The 3D GPR surveys effectively located the wastewater drainage trenches at both sites, in close agreement with locations described in as-built OWS blueprints. Regression analysis of resistivity versus groundwater specific conductivity revealed an inverse relationship, suggesting resistivity ≤ 250 ohm.m was indicative of wastewater impacted groundwater at both sites. The 3D resistivity models identified regions of low resistivity beneath the drainfields relative to background values. Regression analysis of

  11. 454-Pyrosequencing survey of microbiota in adult Spotted Wing Drosophila (SWD) corroborates a core microbiome and additional symbiotic and entomopathogenic bacterial associates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Complete surveys of insect endosymbionts including species of economic importance have until recently been hampered by a lack of high-throughput genetic assays. We used 454-pyrosequencing of the 16S rRNA gene amplicon of adult spotted wing Drosophila (SWD) Drosophila suzukii (Matsumura) from souther...

  12. A geophysical potential field study to image the Makran subduction zone in SE of Iran

    NASA Astrophysics Data System (ADS)

    Abedi, Maysam; Bahroudi, Abbas

    2016-10-01

    The Makran subduction wedge as one of the largest subduction complexes has been forming due to the Arabian oceanic lithosphere subducting beneath the Lut and the Afghan rigid block microplates. To better visualize the subducting oceanic crust in this region, a geophysical model of magnetic susceptibility from an airborne magnetic survey (line spacing about 7.5 km) over the Makran zone located at southeast of Iran is created to image various structural units in Iran plate. The constructed geophysical model from the 3D inverse modeling of the airborne magnetic data indicates a thin subducting slab to the north of the Makran structural zone. It is demonstrated that the thickness of sedimentary units varies approximately at an interval of 7.5-11 km from north to south of this zone in the Iranian plate, meanwhile the curie depth is also estimated approximately < 26 km. It is also shown the Jazmurian depression zone adjacent to the north of the Makran indicates high intensity magnetic anomalies due to being underlain by an ophiolite oceanic basement, while such intensity reduces over the Makran. The directional derivatives of the magnetic field data have subtle changes in the Makran, but strongly increase in the Jazmurian by enhancing and separating different structural boundaries in this region. In addition, the density variations of the subsurface geological layers were determined by 3D inversion of the ground-based gravity data over the whole study area, where the constructed density model was in good agreement with the magnetic one. According to the outputs of the magnetic susceptibility and the density contrast, the Arabian plate subducts to the north under the Eurasia with a very low dip angle in the Makran structural zone.

  13. Robotic Surveying

    SciTech Connect

    Suzy Cantor-McKinney; Michael Kruzic

    2007-03-01

    -actuated functions to be controlled by an onboard computer. The computer-controlled Speedrower was developed at Carnegie Mellon University to automate agricultural harvesting. Harvesting tasks require the vehicle to cover a field using minimally overlapping rows at slow speeds in a similar manner to geophysical data acquisition. The Speedrower had demonstrated its ability to perform as it had already logged hundreds of acres of autonomous harvesting. This project is the first use of autonomous robotic technology on a large-scale for geophysical surveying.

  14. Investigation of Karst Cavities and Earth Subsidence with Combined Application of Boring and Geophysics in the Progress of High-Speed Railway Routes

    NASA Astrophysics Data System (ADS)

    Lehmann, Bodo; Pöttler, Rudolf; Radinger, Alexander; Kühne, Manfred

    In Germany there are a lot of new high-speed railways in planning or under construction. One of these is the new Nuremberg - Ingolstadt railway line and the updated line from Ingolstadt to Munich. These two lines will form part of a high-speed trans-European railway link from Scandinavia via Berlin to Munich and Verona. The 78 km railway line construction project has been divided into three contract sections: Contract Section North, mainly characterised by pure earth and bridge works; Contract Section Centre, with the emphasis mainly on tunnel construction; and Contract Section South, combining earthworks and tunnelling. Extensive geophysical investigations combined with borings are carried out in critical areas between Nuremberg and Ingolstadt. The target of this geological exploration phase is mainly the detection of karst pits and earth subsidences (dolines). In this area these geological objects are an important aspect for the stability and permanent serviceability of the high-speed railway routes. The exploration concept on the open stretch consists of combined geological enquiry, geotechnical work, geophysical investigations and borings, which are positioned at the found anomalies of geophysics. The survey leads to a common interpretation of all information and results. After several test campaigns the combination of at least two geophysical methods yields to the best results. Dependent on the thickness of the overburden layer seismics, micro-gravity and/or georadar are applied from the surface. Additionally tomographic methods are used between boreholes for special topics. Important for the success of the investigation in difficult geological areas are the excellent co-operation between all scientists, engineers and technicians (geologists, geotechnicians, geophysicists, driller, consultants, etc.).

  15. Determination of Sinkholes with Different Geophysical Techniques; A Case Study in Yarımburgaz, Küçükçekmece Lake NW Istanbul, Turkey

    NASA Astrophysics Data System (ADS)

    Karabulut, Savas; Cengiz Cinku, Mualla; Tezel, Okan; Dedecan, Hasan; Oygo, Azat

    2016-04-01

    The Yarımburgaz cave which is located in the city of Istanbul, NW Turkey plays an important host to the first human culture and preserve significant archaeological and paleontological resources. The cave was formed as a result of a subterranean stream erosion on the limestones of the Eocene Kırklareli formation. It has been reported that a double cave with upper and lower entrance chambers exist, although no geophysical research was conducted to detect the cave's trunk passages and the extend of the sediment fill inside the cave. The aim of this study was to test the preferred order for detection the response to different geophysical methods applied on the cave. We therefore carried out an a series of geophysical study to determine the size, position, and depth of sinkholes inside the caves. Integrated methodological approaches including multichannel analysis of surface wave (MASW) 2- microtremor array method, 3-single station microtremor measurements, 4- electrical tomography (ET) measuruments and 5-microgravity imaging showed that the geophysical response was succesfully applied. Based upon the flow-chart we concluded that the microgravity survey should be applied as a first step to detect the air-filled void and the geometry of the cave. The electric tomography method was well applied showing high resistivity values across the voids. The surface wave method showed that the low-velocity zones are detected in various locations of the cave. In addition we the results of MASW and ReMi methods showed clearly the density variation in the lateral direction. Fundamental frequency value above void decraese according the properties of geological units in lateral directional, especially when they are engineering rock like limestone.

  16. Combined interpretation of multiple geophysical techniques: an archaeological case study

    NASA Astrophysics Data System (ADS)

    Riedl, S.; Reichmann, S.; Tronicke, J.; Lück, E.

    2009-04-01

    In order to locate and ascertain the dimensions of an ancient orangery, we explored an area of about 70 m x 60 m in the Rheinsberg Palace Garden (Germany) with multiple geophysical techniques. The Rheinsberg Park, situated about 100 km northwest of Berlin, Germany, was established by the Prussian emperors in the 18th century. Due to redesign of the architecture and the landscaping during the past 300 years, buildings were dismantled and detailed knowledge about some original buildings got lost. We surveyed an area close to a gazebo where, after historical sources, an orangery was planned around the year 1740. However, today it is not clear to what extent this plan has been realized and if remains of this building are still buried in the subsurface. Applied geophysical techniques include magnetic gradiometry, frequency domain electromagnetic (FDEM) and direct current (DC) resistivity mapping as well as ground penetrating radar (GPR). To get an overview of the site, we performed FDEM electrical conductivity mapping using an EM38 instrument and magnetic gradiometry with caesium magnetometers. Both data sets were collected with an in- and crossline data point spacing of ca. 10 cm and 50 cm, respectively. DC resistivity surveying was performed using a pole-pole electrode configuration with an electrode spacing of 1.5 m and a spacing of 1.0 m between individual readings. A 3-D GPR survey was conducted using 200 MHz antennae and in- and crossline spacing of ca. 10 cm and 40 cm, respectively. A standard processing sequence including 3-D migration was applied. A combined interpretation of all collected data sets illustrates that the magnetic gradient and the EM38 conductivity maps is are dominated by anomalies from metallic water pipes from belonging to the irrigation system of the park. The DC resistivity map outlines a rectangular area which might indicate the extension of a former building south of the gazebo. The 3-D GPR data set provides further insights about

  17. Reconnaissance Marine Geophysical Survey for the Shallow Water Acoustics Program

    DTIC Science & Technology

    2012-09-30

    intermittently in evidence, but can be recognized as the base of the sand ridges as it commonly outcrops at the low point of swales between the ridges. 5...Base” reflector is clearly evident at the VC2 site, outcropping to the left in the swale adjecent to the sand ridge. At 3 m of penetration, core

  18. Lake Mohave Geophysical Survey 2002: GIS Data Release

    USGS Publications Warehouse

    Cross, VeeAnn A.; Foster, David S.; Twichell, David C.

    2005-01-01

    This CD-ROM contains sidescan-sonar imagery, sub-bottom reflection profiles, and an interpretive map derived from these data. These data were collected in Lake Mohave, a reservoir behind the Davis Dam and below the Hoover Dam on the Colorado River. These data are veiwable within an Environmental system Research Institute, Inc. (ESRI) Geographic Information system (GIS) ArcView 3.2 project file stored on this CD-ROM

  19. Reconnaissance Marine Geophysical Survey for the Shallow Water Acoustics Program

    DTIC Science & Technology

    2013-09-30

    sequences, forming the base of transgressive systems tracts (Thorne and Swift, 1991). It forms by erosional back-stepping of the equilibrium...transgressive ravinement, associated with ongoing sea level rise since the Last Glacial Maximum (LGM), is often well-imaged in high-resolution acoustic...presence of an erosional lag, which is often diagnostic of the ravinement (Richardson et al., 2001; McBride et al., 2004; Snedden et al., 2011). The

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

    EPA Science Inventory

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

  1. Aerial infrared surveys in the investigation of geothermal and volcanic heat sources

    USGS Publications Warehouse

    ,

    1995-01-01

    This factsheet briefly summarizes and clarifies the application of aerial infrared surveys in geophysical exploration for geothermal energy sources and environmental monitoring for potential volcanic hazards.

  2. A Proposal for an Integrated Geophysical Strategy to "Follow the Water" on Mars

    NASA Technical Reports Server (NTRS)

    Clifford, S. M.; George, J. A.; Stoker, C. R.; Briggs, G.; Beaty, D. W.

    2001-01-01

    . For this reason, any exploration activity (such as drilling) whose success is contingent on the presence of subsurface water, must be preceded by a comprehensive high-resolution geophysical survey capable of assessing whether local reservoirs of water and ice actually exist. Terrestrial experience has demonstrated that the accurate identification of such targets is likely to require the application of multiple geophysical techniques. In this abstract we propose an integrated strategy for the geophysical exploration of Mars that we believe represents the fastest, most cost-effect, and technically capable approach to identifying the state and distribution of subsurface water. Additional information is contained in the original extended abstract.

  3. The role of biominerals in enhancing the geophysical response at hydrocarbon contaminated sites

    NASA Astrophysics Data System (ADS)

    Mewafy, Farag Mohamed

    There are several source mechanisms by which microbial activity in the subsurface can change geophysical signatures. To date the source mechanisms generating the geophysical signatures in microbially active environments remain poorly understood. In this study, we investigated the link between the biogeochemical processes resulting in biotransformation of metallic iron mineral phases and the associated biogeophysical signatures. Hydrocarbon contaminated environments provide excellent laboratories for investigating iron mineral biotransformation. In particular, we investigated the magnetic susceptibility (MS) and the complex conductivity (CC) signatures of a hydrocarbon contaminated site near Bemidji, Minnesota. For the MS study, we investigated the changes in the MS response for cores retrieved from the site as well as down boreholes. The contaminated location revealed two enriched MS zones. The first MS lies within the hydrocarbon smear zone, which is limited to the zone of water table fluctuation with high concentrations of dissolved Fe(II) and organic carbon content. Magnetite and siderite were the dominant minerals formed during this process. However, magnetite was responsible for the bulk of MS changes. The second zone of MS enhancement lies within the vadose zone which is characterized by methane depletion suggesting that aerobic or anaerobic oxidation of methane is coupled to iron-reduction resulting in magnetite precipitation. For the CC work, we conducted laboratory CC measurements along four cores in addition to field CC survey. We found that the real (sigma‧) and imaginary (sigma″) conductivity are higher for samples from within the oil plume especially within the smear zone compared to background uncontaminated samples. Using magnetite as an example of the biometallic minerals in the smear zone at the site, a clear increase in the sigma″ response with increasing magnetite content was observed suggesting that the presence of bio-metallic mineral

  4. GeoMapApp: A Cross-Platform app for Geophysical Data Exploration and Visualisation

    NASA Astrophysics Data System (ADS)

    Goodwillie, A. M.

    2015-12-01

    Apps that provide convenient, integrated access to a range of geophysical data have wide applicability in both research and teaching. GeoMapApp (http://www.geomapapp.org), a free, map-based data discovery and visualisation tool developed with NSF funding at Lamont-Doherty Earth Observatory provides casual and specialist users alike with intuitive access to hundreds of built-in geoscience data sets covering geophysics, geochemistry, geology, oceanography, and cryospherics. Users can also import their own data tables, spreadsheets, shapefiles, grids, and images. Simple manipulation and analysis tools combined with layering capabilities and engaging visualisations provide a powerful app with which to explore and interrogate geoscience data in its proper geospatial context thus helping users to more easily gain deeper insight and understanding from real-world data. The backbone of GeoMapApp is a regularly-updated multi-resolution elevation base map covering the oceans and continents and includes measurements ranging from Space Shuttle terrestrial data to ultra-high-resolution surveys of coral reefs and seafloor hydrothermal vent fields. Examples of built-in geophysical data sets include interactive earthquake locations and focal mechanism (CMT) solutions; underway cruise track profiles; plate tectonic velocities, seafloor crustal age and heat flow; multi-channel seismic reflection profiles; gravity, magnetic, and geoid anomalies; sidescan; subduction zone interface depths; and, EarthScope station locations. Dynamic links point to data sources and additional information. There are dedicated menus for GeoPRISMS, MARGINS, and Ridge2000 data sets. A versatile profiling tool provides instant access to data cross-sections, and contouring and 3-D views are also offered. Tabular data - both imported and built-in - can be displayed in a variety of ways and users can quickly select data points directly from the map. Layer opacity and on/off toggles allow easy data set

  5. Present Status of Geophysics Departments at Universities in Turkey from Perspectives of their Students

    NASA Astrophysics Data System (ADS)

    Karabulut, Savas; Baris Aygordu, Ozan; Benli, Aral

    2015-04-01

    This survey was conducted in order to make the students who are having geophysical engineering education in Turkey evaluate their departments from their own perspectives.By doing this we aimed to make a contribution to the geophysical engineering education and we tried to find out if there were any deficiencies in that matter and also the possible solutions.In this respect aproximately 500 undergraduates from 11 different state universities were asked 25 questions regarding both their socio-economic status and their ideas on their future professions.In the survey the students were asked to state their high-school graduation;whether it is an Anatolian High-school,Vocational high-school or college and if geophysical engineering education was their first choice at the university entrance exams.The students' foreign language status-if there were any- except their mother tongue were asked and also their opinions on geophysical education at their universities.Besides these the students were asked in which fields they study in their department; Seismology, Geophysics or Applied Geophysics and if they found the geophysical equipments adequate in their departments and also the programming languages-like data processing laboratories.In the survey we tried to find out if the students were encouraged to participate in the meetings and congresses in their field by their instructers and if they found the theoretical training adequate besides the practical one.Above all the students answered questions if they had any worries about future job opportunities ; what their goals were after they graduate and if they could easily get access to any kind of Turkish sources in their field and if they were reluctant to work at any jobs part-time or full-time during university.The results of the survey were presented to the Union of Turkish Engineers and Architects and also to the related heads of departments.The most striking parts of this survey were that the students were not edequate

  6. Geophysical measurements and monitoring on the Pechgraben Landslide in Upper Austria

    NASA Astrophysics Data System (ADS)

    Jochum, Birgit; Ottowitz, David; Pfeiler, Stefan; Gruber, Stefanie; Hoyer, Stefan; Supper, Robert; Schattauer, Ingrid

    2016-04-01

    In January 2013, after an intense rainfall of about 400 mm, the historic slope movement northwest of the village of Pechgraben (municipality Großraming, Upper Austria) started to move. Already in early March the landslide with an area of about 7 hectares came to a halt. After the long-lasting rainfall (200mm) from June 1st to 3rd 2013 the Pechgraben landslide was reactivated with an extent of about 80 ha on June 6th. This landslide is therefore the largest in Austria since the last 5 years. Several million cubic meters of loose material was moving towards the settlement area. Already one day later, on June 7th, 2013, emergency measures began immediately. The Geological Survey of Austria (GBA), the University of Natural Resources and Life Sciences, Institute of Mountain Risk Engineering (IAN), and the consultant engineering office Moser/Jaritz as well as the local fire brigade and the federal armed forces supported the Torrent and Avalanche Control with their remediation measures. In addition to the emergency measures, which consisted mainly of water diversion and material removal, a comprehensive monitoring system (GPS, inclinometer, geoelectric monitoring, airborne laserscan and aerial photogrammetry, etc.) has been created in order to document the development of the slope movement and to be able to take further measures if necessary. The geophysical part undertaken by the Geological Survey of Austria consisted of an airborne geophysical survey (EM, magnetics, gamma radiation) as well as several geoelectric profiles to understand the geology and mechanism of the landslide. To monitor the movement, we set up 5 different geoelectrical monitoring profiles, permanent inclinometers, photo monitoring, piezometers, as well as soil humidity and precipitation sensors. Hübl, J., Schraml, K., Lindner, G., Tartarotti, T., Gruber, H., Gasperl, W., Supper, R., Jochum, B., Ottowitz, D., Gruber, S., Marschallinger, R., Moser, G. (2015): Synthesebericht der H

  7. Geophysical Log Database for the Mississippi Embayment Regional Aquifer Study (MERAS)

    USGS Publications Warehouse

    Hart, Rheannon M.; Clark, Brian R.

    2008-01-01

    The Mississippi Embayment Regional Aquifer Study (MERAS) is an investigation of ground-water availability and sustainability within the Mississippi embayment as part of the U.S. Geological Survey Ground-Water Resources Program. The MERAS area consists of approximately 70,000 square miles and encompasses parts of eight states including Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee. More than 2,600 geophysical logs of test holes and wells within the MERAS area were compiled into a database and were used to develop a digital hydrogeologic framework from land surface to the top of the Midway Group of upper Paleocene age. The purpose of this report is to document, present, and summarize the geophysical log database, as well as to preserve the geophysical logs in a digital image format for online access.

  8. Use of noninvasive geophysical techniques for the In Situ Vitrification Program

    SciTech Connect

    Josten, N.E.; Marts, S.T.; Carpenter, G.S.

    1991-11-01

    In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focuses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results.

  9. High-resolution geophysical data from the sea floor surrounding the Western Elizabeth Islands, Massachusetts

    USGS Publications Warehouse

    Pendleton, Elizabeth A.; Twichell, David C.; Foster, David S.; Worley, Charles R.; Irwin, Barry J.; Danforth, William W.

    2011-01-01

    Geophysical and geospatial data were collected in the nearshore area surrounding the western Elizabeth Islands, Massachusetts on the U.S. Geological Survey research vessel Rafael during September 2010 in a collaborative effort between the U.S. Geological Survey and the Massachusetts, Office of Coastal Zone Management. This report describes the results of the short-term goals of this collaborative effort, which were to map the geology of the inner shelf zone of the western Elizabeth Islands and study the geologic processes that have contributed to its evolution. Data collected during the survey include: Bathymetric and sidescan-sonar data, chirp seismic-reflection data , sound velocity profiles, and navigation data. The long-term goals of this project are to provide high-resolution geophysical data that will support research on the influence of sea-level change and sediment supply on coastal evolution and inventory subtidal marine habitat type and distribution within the coastal zone of Massachusetts.

  10. Geophysical Investigations of the Mound City Borrow Pits, Ross County, Ohio

    NASA Astrophysics Data System (ADS)

    Benson, Blair Elizabeth

    Geophysical subsurface imaging is becoming a common practice in archaeology. Non-invasive geophysical methods provide efficient alternatives to costly and invasive excavations, allowing archaeologists to analyze sites before any excavation is done to identify areas of interest. For my thesis, I investigated two prehistoric borrow pits at the Mound City Group (200 BC - 200 AD) in the Hopewell Culture National Historical Park in south-central Ohio. The primary objective of this study was to determine the presence and spatial extent of a clay lining that was emplaced upon the borrow pits by the Hopewell people. Information gleaned from the geophysical investigation was used to assess the degree of site disturbance from agriculture, construction of Camp Sherman, and modern reconstruction of the earthworks. My analysis included a suite of overlapping geophysical surveys consisting of ground-penetrating radar, magnetometry, electromagnetic induction, and electrical resistivity. The geophysical data was ground-truthed with limited auguring and trenching. Analysis of the first borrow pit data showed strong evidence of historical disturbance within the pit from construction of Camp Sherman, including disturbed soil and a buried utility pipe, leaving little of the clay lining present except around the edges of the borrow pit. The geophysical data for the second borrow pit showed less historical damage that was primarily caused from the re-excavation of the pit during the reconstruction of the park. The second borrow pit still retains about half of the clay lining, a finding supported by the results of auguring and trenching. These results are evidence that the borrow pits at Mound City may have also served a purpose as cultural landscape features. The geophysical methods used in this study proved to be an invaluable source of information with minimal disturbance of the site.

  11. A review of integrated geophysical investigations from archaeological and cultural sites under encroaching urbanisation in İzmir, Turkey

    NASA Astrophysics Data System (ADS)

    Drahor, Mahmut Göktuğ

    In the new millennium, globalisation, and with it urbanisation, has been expanding as a consequence of economic development throughout the world. Urbanisation is a major social problem, not only for developing countries but also for developed countries. Urbanisation also has a major impact on archaeological sites and cultural heritages in urbanised zones. Non-destructive investigation techniques, such as geophysics, which uses remote sensing, and is non-invasive, are of great importance in urban areas. We are now capable of solving urbanisation-related problems, and these techniques reduce the cost of projects at urbanised sites. Geophysics has increased the possibilities of new applications in determining intensive urbanisation effects in earth science. Geophysics deals with numerous physical variations such as electricity, electromagnetism, magnetics, acoustics, gravity and radioactivity. There are numerous ways geophysics can be applied in archaeological and cultural heritage studies. In addition the hazard mitigation, infrastructure investigation, waste management, water supply, urban gateways and other factors are documented by geophysics. In recent years, archaeological sites under the encroachment of urbanisation have been investigated on numerous occasions using non-invasive geophysical techniques, allowing parameters such as the depth, dimension and extension of targets to be clearly determined. The term “urban geophysics” has recently been seen in various references related to geophysics and other earth science studies. This study reviews the results of geophysical investigations carried out at important archaeological sites under encroaching urbanisation in the city of İzmir, Turkey.

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    During the spring-summer intersession, we annually offer an intensive three-week field course designed to provide hands-on instruction and training for graduate and upper-level undergraduate students in the acquisition, processing, interpretation, and visualization of marine geological and geophysical data. Now in year four, the course covers high-resolution air gun and streamer 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 first participate in three days of classroom instruction designed to provide theoretical and technical background on each field method and impart geologic context of the study area. Students then travel to the Gulf Coast for a week of at-sea field work. In the field, students rotate between two small research vessels: one vessel, the 22’ aluminum-hulled R/V Lake Itasca, owned and operated by UTIG, is used for multibeam bathymetry, sidescan sonar, and sediment sampling; the other, NOAA’s R/V Manta or the R/V Acadiana, operated by the Louisiana Universities Marine Consortium, is used for high-resolution seismic reflection, CHIRP sub-bottom profiling, gravity coring, and vibracoring. Students assist with survey design, learn systems setup and acquisition parameters, and safe instrument deployment and retrieval techniques. Students also perform on-shore sedimentology lab work, data quality control, data processing and visualization using industry-standard software such as Focus, Landmark, Caris, and Fledermaus. During the course’s final week, students return to the classroom where, collaborating in teams of three, they integrate and interpret data in a final project which examines the geologic history and/or sedimentary processes as typified by the Gulf Coast continental shelf. The course culminates in a series of professional

  13. Use of noninvasive geophysical techniques for the in situ vitrification program

    SciTech Connect

    Josten, N.E.; Marts, S.T.; Carpenter, G.S.

    1991-11-01

    In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focusses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results. The literature review shows that all the ISV objectives are theoretically achievable because they involve physical properties (such as electrical conductivity, density, or magnetization) that can be sensed by geophysical instruments. However, most of the ISV objectives require substantially higher resolution than is achieved in typical waste site investigations, or than has been demonstrated by researches using state-of-the-art techniques. The survey at the INEL simulated waste pit yielded useful, qualitative information on subsurface materials and boundaries; but quantitative information, such as depth, size, or composition of buried materials, was subject to significant uncertainty. For ISV, the usefulness of geophysical characterization depends both on the capabilities of geophysical methods and on an assessment of the amount of uncertainty that is acceptable. Based on a preliminary assessment of these factors, the location of trench boundaries and detection of massive metallic objects are the important achievable objectives using current technology.

  14. Use of noninvasive geophysical techniques for the in situ vitrification program. Volume 3, Discussion and recommendations

    SciTech Connect

    Josten, N.E.; Marts, S.T.; Carpenter, G.S.

    1991-11-01

    In situ vitrification (ISV) is a waste pit remediation technology that can potentially eliminate the need for pit excavation. The ISV program at the Idaho National Engineering Laboratory (INEL) funded this study to evaluate geophysical techniques that might be useful for performing detailed screening of the materials, soil conditions, and local geology of waste pits targeted for remediation. The evaluation focusses on a specific set of characterization objectives developed by ISV engineers. The objectives are based on their assessment of safety, environmental, and cost efficiency issues associated with the ISV process. A literature review of geophysical case histories was conducted and a geophysical survey was performed at the INEL simulated waste pit so that the evaluation could be based on demonstrable results. The literature review shows that all the ISV objectives are theoretically achievable because they involve physical properties (such as electrical conductivity, density, or magnetization) that can be sensed by geophysical instruments. However, most of the ISV objectives require substantially higher resolution than is achieved in typical waste site investigations, or than has been demonstrated by researches using state-of-the-art techniques. The survey at the INEL simulated waste pit yielded useful, qualitative information on subsurface materials and boundaries; but quantitative information, such as depth, size, or composition of buried materials, was subject to significant uncertainty. For ISV, the usefulness of geophysical characterization depends both on the capabilities of geophysical methods and on an assessment of the amount of uncertainty that is acceptable. Based on a preliminary assessment of these factors, the location of trench boundaries and detection of massive metallic objects are the important achievable objectives using current technology.

  15. Geophysical methods for locating abandoned wells

    USGS Publications Warehouse

    Frischknecht, Frank C.; Muth, L.; Grette, R.; Buckley, T.; Kornegay, B.

    1983-01-01

    A preliminary study of the feasibility of using geophysical exploration methods to locate abandoned wells containing steel casing indicated that magnetic methods promise to be effective and that some electrical techniques might be useful as auxiliary methods. Ground magnetic measurements made in the vicinity of several known cased wells yielded total field anomalies with peak values ranging from about 1,500 to 6,000 gammas. The anomalies measured on the ground are very narrow and, considering noise due to other cultural and geologic sources, a line spacing on the order of 50 feet (15.2 m) would be necessary to locate all casings in the test area. The mathematical model used to represent a casing was a set of magnetic pole pairs. By use of a non-linear least squares curve fitting (inversion) program, model parameters which characterize each test casing were determined. The position and strength of the uppermost pole was usually well resolved. The parameters of lower poles were not as well resolved but it appears that the results are adequate for predicting the anomalies which would be observed at aircraft altitudes. Modeling based on the parameters determined from the ground data indicates that all of the test casings could be detected by airborne measurements made at heights of 150 to 200 feet (45.7-61.0 m) above the ground, provided lines spaced as closely as 330 feet (100 m) were used and provided noise due to other cultural and geologic sources is not very large. Given the noise levels of currently available equipment and assuming very low magnetic gradients due to geologic sources, the detection range for total field measurements is greater than that for measurements of the horizontal or vertical gradient of the total intensity. Electrical self-potential anomalies were found to be associated with most of the casings where measurements were made. However, the anomalies tend to be very narrow and, in several cases, they are comparable in magnitude to other small

  16. Geophysical Institute biennial report 1995--1996

    SciTech Connect

    1998-06-01

    The mission of the Geophysical Institute is to understand the basic physical processes governing Earth, especially as they occur in, or are relevant to the Arctic; to train graduate and undergraduate students to play leading roles in tomorrow`s society; to solve applied geophysical problems and develop resource-oriented technology of importance to the state and the nation; and to satisfy the intellectual and technological needs of fellow Alaskans through public service. The variety of subjects studied by the faculty, research staff members, and graduate students at the Geophysical Institute include auroral physics and chemistry, arctic haze, ice fog, atmospheric dynamics, ozone, Alaska weather patterns, regional meteorology and climatology, global climate change, cloud physics and radiation, permafrost, glaciers, sea ice, remote sensing, geothermal energy, tectonics, volcanoes and earthquakes. Summaries are presented of the projects undertaken by the Institute in these fields.

  17. Brief overview of geophysical probing technology

    SciTech Connect

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

    1982-02-01

    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.

  18. Geophysical and Hydrologic Studies of Lake Seepage Variability.

    PubMed

    Toran, Laura; Nyquist, Jonathan; Rosenberry, Donald; Gagliano, Michael; Mitchell, Natasha; Mikochik, James

    2015-01-01

    Variations in lake seepage were studied along a 130 m shoreline of Mirror Lake NH. Seepage was downward from the lake to groundwater; rates measured from 28 seepage meters varied from 0 to -282 cm/d. Causes of this variation were investigated using electrical resistivity surveys and lakebed sediment characterization. Two-dimensional (2D) resistivity surveys showed a transition in lakebed sediments from outwash to till that correlated with high- and low-seepage zones, respectively. However, the 2D survey was not able to predict smaller scale variations within these facies. In the outwash, fast seepage was associated with permeability variations in a thin (2 cm) layer of sediments at the top of the lakebed. In the till, where seepage was slower than that in the outwash, a three-dimensional resistivity survey mapped a point of high seepage associated with heterogeneity (lower resistivity and likely higher permeability). Points of focused flow across the sediment-water interface are difficult to detect and can transmit a large percentage of total exchange. Using a series of electrical resistivity geophysical methods in combination with hydrologic data to locate heterogeneities that affect seepage rates can help guide seepage meter placement. Improving our understanding of the causes and types of heterogeneity in lake seepage will provide better data for lake budgets and prediction of mass transfer of solutes or contaminants between lakes and groundwater.

  19. Comparison of geophysical pedotransfer functions using laboratory measurements

    NASA Astrophysics Data System (ADS)

    Wunderlich, T.; Petersen, H.; Hagrey, S. A. al; Rabbel, W.

    2012-04-01

    can observe a linear relationship between electrical conductivity and permittivity that can be used to determine the GPR velocity distribution from an inverted geoelectric profile in situ. These results are confimed by a comparison with additional field velocity measurements showing good agreement. Acknowledgments: iSOIL (Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping) is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment.

  20. The 1990 Western Pacific Geophysics meeting

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The 1990 Western Pacific Geophysics Meeting was held in Kanazawa, Japan from 15-21 Aug. 1990. This was the first meeting of a new series of meetings for the American Geophysical Union, and it proved to be very successful in terms of the scientific program and attendance, which included over 1,000 participants. The intent of this meeting was an effort on the part of the American Geophysical Union (AGU) and several Japanese geophysical societies to gather individual Earth and space scientists at a major scientific meeting to focus on geophysical problems being studied in the western Pacific rim. The meeting was organized along the lines of a typical AGU annual meeting with some invited talks, many contributed talks, poster sessions, and with emphasis on presentations and informal discussions. The program committee consisted of scientists from both the U.S. and Japan. This meeting provided ample opportunities for U.S. and Japanese scientists to get to know each other and their works on a one-to-one basis. It was also a valuable opportunity for students studying geophysics to get together and interact with each other and with scientists from both the U.S. and Japan. There were 939 abstracts submitted to the conference and a total of 102 sessions designed as a result of the abstracts received. The topics of interest are as follows: space geodetic and observatory measurements for earthquake and tectonic studies; gravity, sea level, and vertical motion; variations in earth rotation and earth dynamics; sedimentary magnetism; global processes and precipitation; subsurface contaminant transport; U.S. Western Pacific Rim initiatives in hydrology; shelf and coastal circulation; tectonics, magmatism, and hydrothermal processes; earthquake prediction and hazard assessment; seismic wave propagation in realistic media; and dynamics and structure of plate boundaries and of the Earth's deep interior.

  1. Geophysical Models for Nuclear Explosion Monitoring

    SciTech Connect

    Pasyanos, M E; Walter, W R; Flanagan, M

    2003-07-16

    Geophysical models are increasingly recognized as an important component of regional calibrations for seismic monitoring. The models can be used to predict geophysical measurements, such as body wave travel times, and can be derived from direct regional studies or even by geophysical analogy. While empirical measurements of these geophysical parameters might be preferred, in aseismic regions or regions without seismic stations, this data might not exist. In these cases, models represent a 'best guess' of the seismic properties in a region, which improves on global models such as the PREM (Preliminary Reference Earth Model) or the IASPEI (International Association of Seismology and Physics of the Earth's Interior) models. The model-based predictions can also serve as a useful background for the empirical measurements by removing trends in the data. To this end, Lawrence Livermore National Laboratory (LLNL) has developed the WENA model for Western Eurasia and North Africa. This model is constructed using a regionalization of several dozen lithospheric (crust and uppermost mantle) models, combined with the Laske sediment model and 3SMAC upper mantle. We have evaluated this model using a number of data sets, including travel times, surface waves, receiver functions, and waveform analysis. Similarly, Los Alamos National Laboratory (LANL) has developed a geophysical model for East Asia, allowing LLNL/LANL to construct a model for all of Eurasia and North Africa. These models continue to evolve as new and updated datasets are used to critically assess the predictive powers of the model. Research results from this meeting and other reports and papers can be used to update and refine the regional boundaries and regional models. A number of other groups involved in monitoring have also developed geophysical models. As these become available, we will be assessing the models and their constitutive components for their suitability for inclusion in the National Nuclear Security

  2. Geophysics: Building E5476 decommissiong, Aberdeen Proving Ground

    SciTech Connect

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

    1992-11-01

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

  3. Geophysics and the search of freshwater bodies: a review.

    PubMed

    Parker, Rachael; Ruffell, Alastair; Hughes, David; Pringle, Jamie

    2010-09-01

    Geophysics may assist scent dogs and divers in the search of water bodies for human and animal remains, contraband, weapons and explosives by surveying large areas rapidly and identifying targets or environmental hazards. The most commonly applied methods are described and evaluated for forensic searches. Seismic reflection or refraction and CHIRPS are useful for deep, open water bodies and identifying large targets, yet limited in streams and ponds. The use of ground penetrating radar (GPR) on water (WPR) is of limited use in deep waters (over 20 m) but is advantageous in the search for non-metallic targets in small ditches and ponds. Large metal or metal-bearing targets can be successfully imaged in deep waters by using towfish magnetometers: in shallow waters such a towfish cannot be used, so a non-metalliferous boat can carry a terrestrial magnetometer. Each device has its uses, depending on the target and location: unknown target make-up (e.g. a homicide victim with or without a metal object) may be best located using a range of methods (the multi-proxy approach), depending on water depth. Geophysics may not definitively find the target, but can provide areas for elimination and detailed search by dogs and divers, saving time and effort.

  4. High-resolution Geophysical Mapping of Submarine Glacial Landforms

    NASA Astrophysics Data System (ADS)

    Jakobsson, M.; Dowdeswell, J. A.; Canals, M.; Todd, B. J.; Dowdeswell, E. K.; Hogan, K. A.; Mayer, L. A.

    2014-12-01

    Glacial landforms are generated from the activity of glaciers and display spatial dimensions ranging from below one meter up to tens of kilometers. Glacial landforms are used as diagnostic features of past activity of ice sheets and glaciers; they are specifically important in the field of palaeoglaciology. Mapping of submarine glacial landforms is largely dependent on geophysical survey methods capable of imaging the seafloor and sub-bottom through the water column. Full "global" seafloor mapping coverage, equivalent to what exists for land elevation, is to-date only achieved by the powerful method of deriving bathymetry from altimeters on satellites like GEOSAT and ERS-1. The lateral resolution of satellite derived bathymetry is, however, limited by the footprint of the satellite and the need to average out local wave and wind effects resulting in values of around 15 km. Consequently, mapping submarine glacial landforms requires for the most part higher resolution than is achievable by satellite derived bathymetry. The most widely-used methods for mapping submarine glacial landforms are based on echo-sounding principles. This presentation shows how the evolution of marine geophysical mapping techniques, in particular the advent of side-scan and multibeam bathymetric sonars, has made it possible to study submarine glacial landforms in unprecedented detail. Examples are shown from the Atlas of Submarine Glacial Landforms: Modern, Quaternary and Ancient, which will be published in late 2015 in the Memoir Series of the Geological Society of London.

  5. Geophysics: Building E5481 decommissioning, Aberdeen Proving Ground

    SciTech Connect

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

    1992-11-01

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

  6. Geophysical Investigations of Structures within Southern Fish Lake Valley, California

    NASA Astrophysics Data System (ADS)

    McBride, K.; Ferguson, J. F.; Oldow, J. S.

    2015-12-01

    The 80km Fish Lake Valley Fault Zone makes up the northern portion of the Furnace Creek - Death Valley Fault Zone, a 250km right lateral oblique strike slip system that accounts for up to 25% of the relative motion between the Pacific and North American Plates. The Cucomongo Canyon Restraining bend lies to the south of Fish Lake Valley, and causes localized uplift. The developmental history of the Cucomongo Canyon restraining bend and the resultant uplift, deformation, and displacement is the focus of an integrated study by the Miles Geoscience Center at the University of Texas at Dallas. This specific part of the study focuses on the southernmost section of Fish Lake Valley, where Paleozoic sedimentary rocks are juxtaposed with Cenozoic sediments on multiple faulted boundaries. Structural constraints are not very well known as the faults are locally obscured by Quaternary alluvial deposits of various ages. Analysis of high resolution topography, produced from LiDAR scanning performed by the Miles team, and imagery shows subtle geomorphic expressions related to faulting. A near surface geophysical survey utilizing high resolution seismic refraction and microGal gravity measurements was done to explore the subsurface beneath the alluvium. Forward models were created to identify faults and ascertain vertical offsets and orientations. The geophysical models indicate a zone of extensional deformation north of the restraining bend

  7. Methods and spatial extent of geophysical Investigations, Mono Lake, California, 2009 to 2011

    USGS Publications Warehouse

    Jayko, A.S.; Hart, P.E.; Childs, J. R.; Cormier, M.-H.; Ponce, D.A.; Athens, N.D.; McClain, J.S.

    2013-01-01

    This report summarizes the methods and spatial extent of geophysical surveys conducted on Mono Lake and Paoha Island by U.S. Geological Survey during 2009 and 2011. The surveys include acquisition of new high resolution seismic reflection data, shipborne high resolution magnetic data, and ground magnetic and gravity data on Paoha Island. Several trials to acquire swath bathymetry and side scan sonar were conducted, but were largely unsuccessful likely due to physical properties of the water column and (or) physical properites of the highly organic bottom sediment.

  8. GETMAG - A New Geophysical Tool

    NASA Astrophysics Data System (ADS)

    Schmidt, P.; Clark, D.; Bick, M.; Binks, R.; Du, J.; Foley, C.; Gnanarajan, S.; Leslie, K.; Sullivan, P.; Thorn, B.; Tilbrook, D.

    2004-05-01

    CSIRO is developing a new instrument for mineral exploration. The instrument, GETMAG, measures the magnetic gradient tensor and the components of the magnetic field. The sensors are high temperature superconducting quantum interference devices (SQUIDs), or HTSs. The acronym is largely historical and stands for Glass Earth Tensor Magnetic Airborne Gradiometer. The GETMAG instument measures magnetic gradients via a novel application of high temperature superconducting tape flip-chipped onto a SQUID sensor. A gradiometer structure incorporating two opposing pick-up loops is patterned onto a tape. Due to the spatial separation of these loops, a magnetic gradient will produce a Meissner shielding current in the tape. The current is magnetically coupled to the SQUID sensor thus providing a direct measurement of the magnetic gradient. The tape is rotated to detect all gradients orthogonal to the axis of rotation. Three rotating tape systems are required to measure the full tensor. The gradients in combination with the TMI yield better resolution for magnetic surveys. Direction to individual sources and their magnetic moments (reduced according to distance) can be determined directly from the tensor. Results from test surveys, where the GETMAG system was rotated manually, show that the gradient can be measured to an accuracy of a few nT/m. It is estimated that improving the mechanical structure, spinning the system at about 600 rpm and using an improved data extraction algorithm can reduce this noise figure by two orders of magnitude. The vector components at this stage are very inaccurate since most of the development undertaken to date has been aimed at measuring the gradients. The systems operate better as gradiometers than as magnetometers and will not challenge total field instruments such as proton precession or alkali-vapour magnetometers as scalar instruments. The GETMAG concept has wide ranging applications in mineral exploration, environmental studies, ordnance

  9. A geophysical and hydrogeological study of aquifers contamination by a landfill

    NASA Astrophysics Data System (ADS)

    Senos Matias, M.; Marques da Silva, M.; Ferreira, P.; Ramalho, E.

    1994-08-01

    Landfills are the classical solution for waste disposal. During the last years there has been a growing concern about the effect of landfills in public health, because leaching water can contaminate nearby aquifers. Hydrogeological studies are very important to investigate and remedy these contamination problems but an integrated use of both geophysical and hydrological methods can be even more effective. In this paper, the groundwater contamination by a landfill, located on very porous and permeable formations, is assessed by both geophysical and hydrogeological techniques. Bearing in mind the geological and hydrogeological characteristics of the area, electrical methods were chosen to carry out the geophysical survey. At first, electromagnetic methods were used and a ground conductivity survey was carried out to determine the contamination plume. Then several resistivity soundings were proposed and two resistivity pseudo-sections obtained so that a more detailed study of the contamination was accomplished. From the geophysical data interpretation, strategically located boreholes were drilled, water samples obtained and chemical analysis carried out. Finally, the overall results are integrated and discussed as well as the merits and disadvantages of the techniques that have been employed.

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

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

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

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

    NASA Astrophysics Data System (ADS)

    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

  12. The use of airborne geophysics for levee classification and assessment

    NASA Astrophysics Data System (ADS)

    Dunbar, Joseph B.

    2011-12-01

    This research is the first known application into using airborne geophysical methods to evaluate and classify levees. This research is an important step toward developing new technologies and methods to rapidly screen and evaluate earthen flood control levees for safety against flooding. An investigation of airborne geophysical methods was conducted on levees in the lower Rio Grande Valley and involved electromagnetic induction, magnetometer, and LiDAR surveys of the levee system. Airborne EM signatures were analyzed by geologic mapping of floodplain depositional environments, examination of published soils data, and drilling of borings. A geographic information system was developed to manage the various data sets and evaluate historic land use changes and development of the flood control systems to better understand the signatures using airborne methods. This research presents information about the historic basis for evaluating and classifying levees, which is based primarily on the federal perspective and flood control experiences in the lower Mississippi River Valley, where national floodplain engineering methods and standards were developed. This research examines the evolution of today's flood control policy, and the development of engineering assessment procedures, and the application of geophysical methods to provide critical information about levee failure mechanisms and assessment of flood control systems. This research demonstrates that topographic base maps and Sengpiel sections showing the results of electrical conductivity or resistivity surveys at different frequencies along the levee corridor provide accurate and valuable information to determine the composition of floodplain soils and the foundation stratigraphy to assess modes of levee failure, to aid in the placement of borings to obtain material properties of the levee and foundation, and to determine the extent of levee reaches with similar properties for the engineering analysis. The main

  13. Circular structures of Bajada del Diablo (Argentina): geophysical signatures

    NASA Astrophysics Data System (ADS)

    Prezzi, C. B.; Orgeira, M. J.; Martinez, O.; Acevedo, R. D.; Ponce, F.; Goldmann, G.; Magneres, I.; Rabassa, J.

    2016-05-01

    Bajada del Diablo is located in the Northern Patagonian Massif, Chubut, Argentina. The study area includes several circular structures found in Miocene olivine basalts of the Quiñelaf Eruptive Complex and in the Late Pliocene/Early Pleistocene Pampa Sastre conglomerates. An impact origin has been proposed for these circular structures. With the aim of further investigate the proposed impact origin, topographic, gravimetric, magnetic, resistivity, palaeomagnetic and electromagnetic surveys in two circular structures (`8' and `G') located in Pampa Sastre conglomerates and in basalts of the Quiñelaf Eruptive Complex were carried out. The new geophysical results support the hypothesis of an impact origin. However, the confirmation of such an origin through the findings of shock metamorphism evidences and/or the recovery of meteorites remains elusive.

  14. GADB: A database facility for modelling naturally occurring geophysical fields

    NASA Technical Reports Server (NTRS)

    Dampney, C. N. G.

    1983-01-01

    In certain kinds of geophysical surveys, the fields are continua, but measured at discrete points referenced by their position or time of measurement. Systems of this kind are better modelled by databases built from basic data structures attuned to representing traverses across continua that are not of pre-defined fixed length. The general Array DataBase is built on arrays (ordered sequencies of data) with each array holding data elements of one type. The arrays each occupy their own physical data set, in turn inter-related by a hierarchy to other arrays over the same space/time reference points. The GADB illustrates the principle that a data facility should reflect the fundamental properties of its data, and support retrieval based on the application's view. The GADB is being tested by its use in NASA's project MAGSAT.

  15. Inequality constraint in least-square inversion of geophysical data

    SciTech Connect

    Kim, Hee Joon; Song, Yoonho; Lee, Ki Ha

    1998-06-01

    This paper presents a simple, generalized parameter constraint using a priori information to obtain a stable inverse of geophysical data. In the constraint the a priori information can be expressed by two limits: lower and upper bounds. This is a kind of inequality constraint, which is usually employed in linear programming. In this paper, we have derived this parameter constraint as a generalized version of positiveness constraint of parameter, which is routinely used in the inversion of electrical and EM data. However, the two bounds are not restricted to positive values. The width of two bounds reflects the reliability of ground information, which is obtained through well logging and surface geology survey. The effectiveness and convenience of this inequality constraint is demonstrated through the smoothness-constrained inversion of synthetic magnetotelluric data.

  16. Geophysical investigations of concealed faults near Yucca Mountain, Southwest Nevada

    USGS Publications Warehouse

    Ponce, D.A.

    1993-01-01

    Detailed gravity and ground magnetic data collected along surveyed traverses across Midway Valley, on the eastern flank of Yucca Mountain, Nevada reveal that these methods can be used to delineate concealed faults. These studies are part of an effort to evaluate faulting in the vicinity of the proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. The largest gravity and magnetic anomaly in the vicinity of Midway Valley is associated with the Paintbrush fault on the west flank of Alice Ridge. Geophysical data infer a vertical offset of about 200 m (650 ft). Another prominent gravity and magnetic anomaly is associated with the Bow Ridge fault in the western part of Midway Valley.

  17. Geophysical Investigations Over the Archaeological site of Rirha (Morocco)

    NASA Astrophysics Data System (ADS)

    Senechal, G.; Rousset, D.; Callegarin, L.; Kbiri Alaoui, M.

    2007-05-01

    The roman site of Rirha has been evidenced in the 1920's and loosely studied until nowadays. Archeaological evidences show a pre-roman to medieval occupation of the site. Excavations have revealed thermae and other buildings while their context, rural villa or urban domus was still unknown. A new survey began in 2004, focusing on the pre-roman occupation of the site, as well as the characterization of the roman occupation. The zone of interest, a hill in a river loop, is about 11hectares. A comprehensive geophysical survey was out of reach, so geophysical tests have been carried on with two goals. The first one was to identify the suitable methods adapted to this, the second one was to use these preliminary results to distinguish between rural or urban settings for the roman site. The first survey has been conducted in April 2005, using conductivitymeter (Geonics EM38) in order to get informations about the spatial organization of the site. The selected zone was located in an unsurveyed part of the site. Resistivity maps show orthogonal structures, far from the known roman remains. This result supports the hypothesis of the site being a roman town and not a large farm or a villa. The second survey has been carried on in February 2006 and involved GPR and DC tomography, in very wet conditions. DC survey aimed at constraining the geological context of the site and at finding the remains of a large wall described by early authors. GPR experiment was primarily a test of the tool there and has been conducted on the previously studied area to get some depth information. The geological context has been studied by carrying on a 2D vertical section, 330 m long and 25 meters deep. showing a substratum of river deposit (sand, gravel, pebbles with possible clay layers) located at 8 to 10 m deep. Above this formation, we observe a very conductive layer interpreted as a clay formation (3 to 6 m thick) and finally, just below the surface, a laterally heterogeneous formation with

  18. Global Change Geodesy: A Geophysical Perspective

    NASA Astrophysics Data System (ADS)

    Mitrovica, J. X.

    2014-12-01

    It is a truism that as the precision of geodetic measurement techniques improves, the accuracy of the geophysical modeling of processes that contribute to the observations must keep pace. Studies of the Earth's response to human-induced climate change provide many notable, and pressing, illustrations of this axiom. For example, estimates of recent ice volume changes, as inferred from satellite gravity measurements, tide gauge and satellite-altimetry records of sea level changes, or astronomical and space-geodetic constraints on Earth rotation, require improved theoretical and numerical treatments of ongoing glacial isostatic adjustment in response to the last ice age. However, the interplay between geodesy and geophysics is not a one-way street; geophysical modeling has emphasized, for example, that the geographic variability in sea level measurements - once considered a nuisance in efforts to infer long term trends - provides a powerful constraint on both the individual sources of meltwater and their sum. In this talk, I will discuss a series of case studies that demonstrate how interdisciplinary research at the interface between geodesy and geophysics has recently resolved several outstanding problems in global change research, including Walter Munk's enigma of global sea-level rise and the apparent failure to close the budget of twentieth century sea level. Moreover, in the same interdisciplinary context, I will highlight uncertainties that currently limit our understanding of polar ice sheet stability in a progressively warming world.

  19. Digital geologic and geophysical data of Bangladesh

    USGS Publications Warehouse

    Persits, Feliks M.; Wandrey, C.J.; Milici, R.C.; Manwar, Abdullah

    1997-01-01

    The data set for these maps includes arcs, polygons, and labels that outline and describe the general geologic age and geophysical fields of Bangladesh. Political boundaries are provided to show the general location of administrative regions and state boundaries. Major base topographic data like cities, rivers, etc. were derived from the same paper map source as the geology.

  20. Studies in geophysics groundwater contamination by Geophysics Study Committee

    SciTech Connect

    Not Available

    1984-01-01

    The book cites the massive application of chemicals to the land and the possibility of groundwater contamination and the extent of contamination on the natural scale. Movement by microscopic and macroscopic processes is discussed together with a description of chemical processes involved. This is followed by description of shallow land disposal of municipal waste and deep well injection. Several specific examples are then described and discussed. For example, the section on the Love Canal discusses a modeling system and recommendations for receiving the problem. Each section includes an abstract and a comprehensive set of references. It is well written, comprehensive and a valuable addition to the library of anyone working on the environmental problems of groundwater contamination.