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Sample records for geophysics building e5190

  1. 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.

  2. Geophysics: Building E5190 decommissioning, Aberdeen Proving Ground. Interim progress report

    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.

  3. Initial building investigations at Aberdeen Proving Ground, Maryland: Building E5190

    SciTech Connect

    Brubaker, K.L.; Dougherty, J.M.; Tome, C.

    1993-10-01

    As part of a building decommissioning and demolition program at Aberdeen Proving Ground, a detailed inspection of each target building is conducted in order to characterize and describe the state of the building as it currently exists and to identify areas potentially contaminated with toxic or other hazardous substances. Room surfaces, drains and sumps, remaining equipment, and such associated exterior aboveground and underground appurtenances as tanks and pipelines are among the features, generically termed compartments, that may be potentially contaminated. Detailed drawings are prepared to illustrate the existing structure of each building. This report presents the results of the inspection of building E5190 in the Edgewood/Canal Creek area of Aberdeen Proving Ground. This building houses a 10,000-gal tank formerly used to store xylene. Eleven potentially contaminated compartments were identified in this building and its vicinity.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Geophysics: Building E5440 decommissioning, Aberdeen Proving Ground. Interim progress report

    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.

  14. Geophysics: Building E5476 decommissiong, Aberdeen Proving Ground. Interim progress report

    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.

  15. Geophysics: Building E5375 decommissioning, Aberdeen Proving Ground. Interim progress report

    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.

  16. Geophysics: Building E5282 decommissioning, Aberdeen Proving Ground. Interim progress report

    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.

  17. New Geophysical Data On The Remains of Ancient Buildings In The Vicinity of Kazan Kremlin (russia)

    NASA Astrophysics Data System (ADS)

    Slepak, Z.

    Beside the Kremlin of Kazan, a monument of culture and architecture of the 16th-18th centuries, there were many other buildings near the historical territory of the Kremlin which are now partly or wholly destroyed, such as the Bogoroditsky nunnery. New geophysical and archaeological studies have been conducted here in 2000-01 to locate the position of the buildings more precisely. The main geophysical method employed was electromagnetic sounding by the stabilisation of EM-field using the device SIm- & cedil;pulseAuto M-1/0-20T for studying the upper geological layers including the daylight surface. EM-sounding with sampling intervals of 0.5-2.0 m resulted in vertical sec- tions of total electrical conductivity S(H). At some points, high-precision gravimeter survey was also conducted. Subsequent archaeological excavations completely con- firmed the acquired geophysical information and its interpretation. Among the studied objects within the KremlinSs boundary were the bell tower of the Blagoveschensky Cathedral, fortress wall of the 12th century and remains of the KhanSs Palace. The re- mains of the destroyed Our Lady Summer Cathedral, tower and the nunnerySs fence were found in the Bogoroditsky nunnery.

  18. Geophysics: Building E5481 decommissioning, Aberdeen Proving Ground. Interim progress report

    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.

  19. Interim progress report -- geophysics: Decommissioning of Buildings E5974 and E5978, Aberdeen Proving Ground

    SciTech Connect

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

    1992-11-01

    Buildings E5974 and E5978, located near the mouth of Canal Creek, were among 10 potentially contaminated sites in the Westwood and Canal Creek 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 the complementary technologies of magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeters of the buildings to guide a sampling program prior to decommissioning and dismantling. The magnetic anomalies and the electrically conductive areas around these buildings have a spatial relationship similar to that observed in low-lying sites in the Canal Creek area; they are probably associated with construction fill. Electrically conductive terrain is dominant on the eastern side of the site, and resistive terrain predominates on the west. The smaller magnetic anomalies are not imaged with ground radar or by electrical profiling. The high resistivities in the northwest quadrant are believed to be caused by a natural sand lens. The causes of three magnetic anomalies in the high-resistivity area are unidentified, but they are probably anthropogenic.

  20. Environmental geophysics: Building E3640 Decommissioning, Aberdeen Proving Ground, Maryland. Interim progress report

    SciTech Connect

    McGinnis, L.D.; Miller, S.F.; Borden, H.M.; Benson, M.A.; Thompson, M.D.; Padar, C.A.; Daudt, C.R.

    1995-01-01

    Building E3640 is a potentially contaminated site in the Edgewood area of Aberdeen Proving Ground. Noninvasive geophysical survey techniques, including magnetics, EM-31, EM-61, and ground-penetrating radar, were used as part of a sampling and monitoring program prior to decommissioning and dismantling of the building. Complex and large-amplitude anomalies caused by aboveground metal in this area obscure many smaller features produced by subsurface sources. No underground storage tanks were found in the areas surveyed. Major anomalies produced by subsurface sources include the following: EM-61 and EM-31 lineaments caused by a water line extending north from the south fence; a broad positive magnetic anomaly caused by magnetic fill north of the material and drum storage area and northeast of E3640; a 30-ft-wide band of EM-31 anomalies extending from the front gate to the southeast comer of E3640 and a coincident EM-61 anomaly produced by buried utilities; ground-penetrating radar images along three lines extending from a sump at the northeast comer of E3640 to the eastern fence; and EM-61, EM-31, and magnetic anomalies caused by overhead and underground pipes extending south from the north fence. Smaller, unidentified, localized anomalies observed throughout the survey area are also described in this report.

  1. Structural geology and geophysics as a support to build a hydrogeologic model of granite rock

    NASA Astrophysics Data System (ADS)

    Martinez-Landa, Lurdes; Carrera, Jesús; Pérez-Estaún, Andrés; Gómez, Paloma; Bajos, Carmen

    2016-06-01

    A method developed for low-permeability fractured media was applied to understand the hydrogeology of a mine excavated in a granitic pluton. This method includes (1) identifying the main groundwater-conducting features of the medium, such as the mine, dykes, and large fractures, (2) implementing this factors as discrete elements into a three-dimensional numerical model, and (3) calibrating these factors against hydraulic data . A key question is how to identify preferential flow paths in the first step. Here, we propose a combination of several techniques. Structural geology, together with borehole sampling, geophysics, hydrogeochemistry, and local hydraulic tests aided in locating all structures. Integration of these data yielded a conceptual model of the site. A preliminary calibration of the model was performed against short-term (< 1 day) pumping tests, which facilitated the characterization of some of the fractures. The hydraulic properties were then used for other fractures that, according to geophysics and structural geology, belonged to the same families. Model validity was tested by blind prediction of a long-term (4 months) large-scale (1 km) pumping test from the mine, which yielded excellent agreement with the observations. Model results confirmed the sparsely fractured nature of the pluton, which has not been subjected to glacial loading-unloading cycles and whose waters are of Na-HCO3 type.

  2. Robust Library Building for Autonomous Classification of Downhole Geophysical Logs Using Gaussian Processes

    NASA Astrophysics Data System (ADS)

    Silversides, Katherine L.; Melkumyan, Arman

    2016-12-01

    Machine learning techniques such as Gaussian Processes can be used to identify stratigraphically important features in geophysical logs. The marker shales in the banded iron formation hosted iron ore deposits of the Hamersley Ranges, Western Australia, form distinctive signatures in the natural gamma logs. The identification of these marker shales is important for stratigraphic identification of unit boundaries for the geological modelling of the deposit. Machine learning techniques each have different unique properties that will impact the results. For Gaussian Processes (GPs), the output values are inclined towards the mean value, particularly when there is not sufficient information in the library. The impact that these inclinations have on the classification can vary depending on the parameter values selected by the user. Therefore, when applying machine learning techniques, care must be taken to fit the technique to the problem correctly. This study focuses on optimising the settings and choices for training a GPs system to identify a specific marker shale. We show that the final results converge even when different, but equally valid starting libraries are used for the training. To analyse the impact on feature identification, GP models were trained so that the output was inclined towards a positive, neutral or negative output. For this type of classification, the best results were when the pull was towards a negative output. We also show that the GP output can be adjusted by using a standard deviation coefficient that changes the balance between certainty and accuracy in the results.

  3. Robust Library Building for Autonomous Classification of Downhole Geophysical Logs Using Gaussian Processes

    NASA Astrophysics Data System (ADS)

    Silversides, Katherine L.; Melkumyan, Arman

    2017-03-01

    Machine learning techniques such as Gaussian Processes can be used to identify stratigraphically important features in geophysical logs. The marker shales in the banded iron formation hosted iron ore deposits of the Hamersley Ranges, Western Australia, form distinctive signatures in the natural gamma logs. The identification of these marker shales is important for stratigraphic identification of unit boundaries for the geological modelling of the deposit. Machine learning techniques each have different unique properties that will impact the results. For Gaussian Processes (GPs), the output values are inclined towards the mean value, particularly when there is not sufficient information in the library. The impact that these inclinations have on the classification can vary depending on the parameter values selected by the user. Therefore, when applying machine learning techniques, care must be taken to fit the technique to the problem correctly. This study focuses on optimising the settings and choices for training a GPs system to identify a specific marker shale. We show that the final results converge even when different, but equally valid starting libraries are used for the training. To analyse the impact on feature identification, GP models were trained so that the output was inclined towards a positive, neutral or negative output. For this type of classification, the best results were when the pull was towards a negative output. We also show that the GP output can be adjusted by using a standard deviation coefficient that changes the balance between certainty and accuracy in the results.

  4. 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.

  5. 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...

  6. 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)

  7. 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)

  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. 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

  10. Sustainable urban development and geophysics

    NASA Astrophysics Data System (ADS)

    Liu, Lanbo; Chan, L. S.

    2007-09-01

    development and geophysics' in Journal of Geophysics and Engineering is a response to the call for the development of novel geophysical techniques especially applicable to city settings. It consists of 11 papers which are selected and expanded from a collection of papers presented to the special sessions on 'Sustainable Urban Development and Geophysics' (U14A, U15A, and U41B) in the Union section of the Western Pacific Geophysics Meeting held in Beijing, China, on 22-27 July 2006 [3]. This indicates that new and innovative geophysical applications in urban settings have emerged, and these innovations may be potentially useful for the planning, implementation, and maintenance of urban infrastructure systems. These 11 research papers can be divided into three groups: (1) geophysics and urban infrastructure; (2) geophysics and urban environment; and (3) geophysical investigations associated with geological hazards. The first group of papers focuses on urban infrastructure. Fred Stumm et al reported a geohydrologic assessment of fractured crystalline bedrock with borehole radar in Manhattan, New York in preparation for the construction of a new water tunnel. Using GPR, Xie et al conducted a quality control study of the walls of the river-crossing highway tunnel in Shanghai. For the same purpose, S Liu et al investigated the effect of concrete cracks on GPR signatures using a numerical simulation technique. Sun et al, using seismic surface waves, investigated road beds and the degree of weathering of the marble fence in the Forbidden City, Beijing. In the second group of papers, using a numerical simulation technique, L Liu et al studied the effect of a building coordinate error on sound wave propagation with the aim of locating sound sources in urban settings. Chan et al studied the abundance of radio elements in weathered igneous bedrock in Hong Kong for the purpose of the promotion of public health in the urban environment. The third group includes five papers on geo

  11. 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...

  12. 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.

  13. Investigation of a large collapse sinkhole affecting a multi-storey building by means of geophysics and the trenching technique (Zaragoza city, NE Spain)

    NASA Astrophysics Data System (ADS)

    Gutiérrez, F.; Galve, J. P.; Lucha, P.; Bonachea, J.; Jordá, L.; Jordá, R.

    2009-09-01

    An active sinkhole around 100 m long has been investigated in the city of Zaragoza (NE Spain). Subsidence activity on this depression, including the sudden occurrence of a collapse sinkhole 5 m across, led to the abandonment of a factory in the 1990s. At the present time, a building with 100 flats and shallow pad foundations partially built on the sinkhole, is affected by rapid differential settlement. The development of the sinkhole results from the karstification of the halite- and glauberite- bearing bedrock and the sagging and collapse of the overlying bedrock and alluvium, more than 30 m thick. GPR and electrical resistivity profiles have provided information on the distribution and geometry of the subsidence structure. The application of the trenching technique and geochronological methods (AMS and OSL dating) has allowed us to infer objective and practical data on the sinkhole including (1) Limits of the subsidence structure, (2) subsidence mechanisms, (3) cumulative subsidence (>408 cm), (4) subsidence rates on specific failure planes (>1.8 cm/year), (5) episodic displacement regime of some fault planes. The available information indicates that the progressive deformation recorded in the building will continue and might be punctuated by events of more rapid displacement. This work illustrates the practicality of the trenching technique for the study of sinkholes in mantled karst areas.

  14. 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.

  15. 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.

  16. 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

  17. An optimized workflow for building 3D models from balanced sections and potential field geophysics: a study case in NE Spain.

    NASA Astrophysics Data System (ADS)

    Ayala, Conxi; Izquierdo-Llavall, Esther; Pueyo, Emilio Luis; Rubio, Félix; Rodríguez-Pintó, Adriana; María Casas, Antonio; Oliva-Urcía, Belén; Rey-Moral, Carmen

    2015-04-01

    Obtaining an accurate 3D image of the geometry and physical properties of geological structures in depth is a challenge regardless the scale and the aim of the investigation. In this framework, assessing the origin of the uncertainties and reducing them is a key issue when building a 3D reconstruction of a target area. Usually, this process involves an interdisciplinary approach and also the use of different software whose inputs and outputs have to be interoperable. We have designed a new workflow for 2.5D and 3D geological and potential field modelling, especially useful in areas where no seismic data is available. The final aim is to obtain a 3D geological model, at a regional or local scale, with the smaller uncertainty as possible. Once the study area and the working scale are is decided, the first obvious step is to compile all preexisting data and to determine its uncertainties. If necessary, a survey will be carried out to acquire additional data (e.g., gravity, magnetic or petrophysical data) to have an appropriated coverage of information and rock samples. A thorough study of the petrophysical properties is made to determine the density, magnetic susceptibility and remanence that will be assigned to each lithology, together with its corresponding uncertainty. Finally, the modelling process is started, and it includes a feedback between geology and potential fields in order to progressively refine the model until it fits all the existing data. The procedure starts with the construction of balanced geological cross sections from field work, available geological maps as well as data from stratigraphic columns, boreholes, etc. These geological cross sections are exported and imported in GMSYS software to carry out the 2.5D potential field modelling. The model improves and its uncertainty is reduced through the feedback between the geologists and the geophysicists. Once the potential field anomalies are well adjusted, the cross sections are exported into 3

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. Integrated Software Framework for Geophysical Data Processing

    NASA Astrophysics Data System (ADS)

    Chubak, G. D.; Morozov, I. B.

    2005-12-01

    An integrated software framework for geophysical data processing was designed by extending a seismic processing system developed previously. Unlike other systems, the new processing monitor is essentially content-agnostic, supports structured multicomponent seismic data streams, multidimensional data objects, and employs a unique backpropagation execution logic. This results in an unusual flexibility of processing, allowing the system to handle nearly any geophysical data. The core package includes nearly 190 tools for seismic, travel-time, and potential-field processing, interfaces to popular graphics and other packages (such as Seismic Unix and GMT). The system also offers an extensive processing environment, including: 1) a modern and feature-rich Graphical User Interface allowing submission of processing jobs and interaction with them during run time, 2) parallel processing capabilities, including load distribution on Beowulf clusters or local area networks; 3) web service operation allowing submission of complex processing jobs to shared remote servers; 4) automated software update service for code distribution to multiple systems, 5) automated online documentation, and 6) software development utilities. The core package was used in several areas of seismology (shallow, reflection, crustal wide-angle, and teleseismic) and in 3D potential-field processing. As a first example of its application, the new web service component (http://seisweb.usask.ca/SIA/ws.php).was used to build a library of processing examples, ranging from simple (UTM coordinate transformations or calculation of great-arc distances) to more complex (such as synthetic seismic modeling).

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Correcting Geophysical Fallacies

    NASA Astrophysics Data System (ADS)

    Barbat, W. N.

    2013-12-01

    The escape velocity from a Big Bang explosion would greatly exceed the speed of light, which is impossible; William Tifft's (1976-77) observations of a common stepwise decline in photon size of 72.5 km/sec replaces a universal Doppler Red Shift, so the universe is not expanding; and the idea that all the mass and energy of the universe were instantly created is unscientific. Joseph Larmor's 1897 equation relates the radiation of photons from a moving electric charge to the square of a change of the acceleration of the charge. Hence the continual centripetal acceleration of orbiting electrons continually radiates low grade photon heat (Zero Point Energy). Shpenkov and Kreidik (2008) found that the heat source which sustains the Cosmic Background Energy at the measured peak blackbody temperature of 2.725+/-0.002K must be due to radiation from the orbital electron motion of hydrogen at its fundamental period, which they calculated to be 2.7289K. Cosmic Background Energy is not left over from a Big Bang 13 billion years ago. Of course, if nature can create energy, then it is reasonable to expect that man can create energy too. Importantly, the creation of photons by orbiting electrons and spinning protons also creates mass. Isaac Newton showed in Book 3 of Opticks that light rays bend as they pass closely over a sharp knife edge, and that the closer the ray is to the knife edge, the more the light path bends. Newton thus showed that corpuscles of light (photons) obey the law of gravitation, so photons possess mass. Photon creation inside stars builds up intense heat and pressure, splitting photons into electrons and positrons. A large positron and photon can apparently combine into a three lump particle with a charge of plus one, making a new proton. Hollow electrons can apparently surround a proton, making a neutron for fission. A small spun-off star advances up the main sequence until a buildup of iron cools and shrinks the core from its hydrogen envelope, leaving a

  7. 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.

  8. A New Social Contract for Geophysics

    NASA Astrophysics Data System (ADS)

    Malone, T. F.

    2002-12-01

    The Golden Age for geophysical research that followed the IGY set the stage for a new era of interaction among science, technology, and society. World population and the average economic productivity of individuals have both continued to grow exponentially during the past 50 years with the result that by the 1980s the demands of the human economy on the finite renewable resources of planet Earth were approximately equal to the natural regenerative capacities of planetary ecosystems. These demands are now "overshooting" those regenerative powers by about 20 per cent (1). The result could be a collapse in the life-supporting capacity of global ecosystems during coming decades, with tragic implications for civilized society. Novel modes of collaboration among all disciplines and all sectors of society are urgently needed to transform a potential catastrophe into the attractive vision that is now within reach as a result of rapidly expanding human knowledge, emerging technologies for sharing that knowledge (2), and the set of ethical principles for sustainable development contained in the Earth Charter (3). This prospect challenges geophysicists and scholars in all disciplines to forge a new and broadly based contract with society (4). 1. Wackernagel M. et al. 2002. "Tracking the ecological overshoot of the human economy." Proc. Natl. Acad. Sci. USA, Vol. 99, Issue 14, 9266-9271, July 9. 2. Malone T. and Yohe G. 2002. "Knowledge partnerships for a sustainable, equitable, and stable society." J. of Knowledge Management, Vol. 6, No. 4, October (in press). 3. www.earthcharter.org 4. Malone T. 1997. "Building on the legacies of the Intenational Geophysical Year." Transactions, AGU, Vol.78, No. 15, pp. 185-191.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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

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

    NASA Astrophysics Data System (ADS)

    Komatina, Snezana; Timotijevic, Zoran

    1999-03-01

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

  2. A Research of the Application Geophysical Methods to the Polluted Site and the river bottom mud in Geophysical Methods

    NASA Astrophysics Data System (ADS)

    Cheng, S.; Liu, H. C.

    2013-12-01

    Many site investigations have found that DNAPL is able to penetrate the low permeable layer such as clay or silt-caly layer in subsurface environment. The cumulated DNAPL within the low permeable Layer will gradually diffuse to the high permeable layer to affect he accuracy of investigation and remedial design. As to the deeper zone affected by the penetration of DNAPL, the conventional sampling design investigating only the first unconfined aquifer is no longer suitable for DNAPL investigation. Precisely define the boundary and the distribution of high and low permeable layer is the key to conduct a successful DNAPL investigation. Point information derived from the conventional bore-hole sampling is difficult to be used for locating the DNAPL pollution due to the uncertainty of DNAPL migration and the soluble-phase distribution of the DNAPL partitioned into ground water between the low and high permeable layer. Recently, non-invaded technologies such as geophysical technology have been introduced to provide the plane and space information of pollution in subsurface by integrating few bore-hole dates. The most common used geophysical technologies are ground-penetrating radar method (GPR) and electrical resistivity tomography (ERT). Both methods have their limitations on the pollution investigation when there are interferences exist such as building structure or heavy pavement. A new geophysical technology, geophysical well logging has been developed to overcome above limitations. The information of multi-wells logging could be used to interpret the permeability of subsurface, the dominate flow path and the hot-spot for evaluating the distribution of pollution and the efficiency of remediation in different time sequences. This study would first discuss how DNAPL and its soluble-phase components invade into the low permeable layer based on the field observation. Then, the importance of geophysical technology is introduced with comparing to the limitations of bore

  3. 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

  4. 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.

  5. 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.

  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. 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

  8. Streamlined Archaeo-Geophysical Data Processing and Integration for Department of Defense Field Use

    DTIC Science & Technology

    2014-09-30

    cultural resource management (CRM) support to Department of Defense (DoD) installations. This project has (1) created ArchaeoFusion, a new user-friendly...DoD geophysical users, representatives of federal, state, and tribal Historic Preservation offices, federal and state resource managers , and other...65 Figure 20. Geomatics II classroom in the J.B. Hunt Center for Academic Excellence Building

  9. 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

  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. 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.

  17. 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.

  18. 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...

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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)

  5. 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)

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

    Izmir is the 3rd largest city of Turkey following Istanbul and Ankara in terms of population, industrial density and contribution to the national economy. Izmir city is located very close to the active faults, has very high seismic risk and develops rapidly on thick and Quaternary-Neogene aged young sediments. Three different tectonic belts take place in Izmir precincts. One of these belts which shapes the Menderes massif at east consists of very thick mica schist unit at basement and a marble stack which formed by the metamorphism of the platform type carbonates. Another tectonic belt named "Izmir-Ankara zone" take place at western part of massif and around Izmir city there is another tectonic belt which is generally flysch characterized. "Karaburun Belt" is at west of "Izmir-Ankara zone" comprised by a thick Mesozoic carbonate stack which precipitated at platform conditions. Izmir and its surroundings, has been the scene of intense earthquake activity since the historical period. The most of earthquake epicenters are at Aegean Sea and take place between Karaburun-Chios Island, Izmir Bay-Lesbos Island and Doğanbey Cape-Samos Island. A number of earthquakes occurs on the remaining land mass between the Aegean Sea and the western part of the Gediz graben. Izmir city to be the center of the 50-60 km radius, there are active faults that may pose a risk by generating potential earthquakes for Izmir metropolitan area and its surroundings. Propagation of earthquake waves towards to surface can be affected considerably by unconsolidated soil structures of Izmir. While occurrence of shallow and large scaled earthquakes, mechanism of soil amplification, liquefaction in sandy soils and losses of bearing capacity in clayey soil can be expected that they are particularly effective on earthquake performance of both buildings and industrial areas. Also some conditions such as; physical parameters of alluvial soil, high groundwater level and basin geometry, which cause soil

  16. 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

  17. 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.

  18. A Geophysical Flow Experiment in a Compressible Critical Fluid

    NASA Technical Reports Server (NTRS)

    Hegseth, John; Garcia, Laudelino

    1996-01-01

    The first objective of this experiment is to build an experimental system in which, in analogy to a geophysical system, a compressible fluid in a spherical annulus becomes radially stratified in density through an A.C. electric field. When this density gradient is demonstrated, the system will be augmented so that the fluid can be driven by heating and rotation and tested in preparation for a microgravity experiment. This apparatus consists of a spherical capacitor filled with critical fluid in a temperature controlled environment. To make the fluid critical, the apparatus will be operated near the critical pressure, critical density, and critical temperature of the fluid. This will result in a highly compressible fluid because of the properties of the fluid near its critical point. A high voltage A.C. source applied across the capacitor will create a spherically symmetric central force because of the dielectric properties of the fluid in an electric field gradient. This central force will induce a spherically symmetric density gradient that is analogous to a geophysical fluid system. To generate such a density gradient the system must be small (approx. 1 inch diameter). This small cell will also be capable of driving the critical fluid by heating and rotation. Since a spherically symmetric density gradient can only be made in microgravity, another small cell, of the same geometry, will be built that uses incompressible fluid. The driving of the fluid by rotation and heating in these small cells will be developed. The resulting instabilities from the driving in these two systems will then be studied. The second objective is to study the pattern forming instabilities (bifurcations) resulting from the well controlled experimental conditions in the critical fluid cell. This experiment will come close to producing conditions that are geophysically similar and will be studied as the driving parameters are changed.

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

    NASA Astrophysics Data System (ADS)

    Eppelbaum, L. V.

    2012-04-01

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

  20. 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

  1. 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...

  2. Geophysical prospecting in archaeology: investigations in Santa Venera, south suburb of Poseidonia-Paestum, Campania, southern Italy

    NASA Astrophysics Data System (ADS)

    Loperte, A.; Satriani, A.; Bavusi, M.; Lapenna, V.; Del Lungo, S.; Sabelli, R.; Gizzi, F. T.

    2011-09-01

    This paper is the result of a joint work between geophysicists and archaeologists in which the authors have used geophysical techniques to investigate the Greek and Roman settlement of Paestum, southern Italy for preventive archaeological research (commonly termed 'rescue archaeology') on an area of the ancient settlement affected by new building work and infrastructure. Starting from a background analysis of the archaeological and geological features of the site, an integrated geophysical approach based on magnetic, GPR and geoelectrical surveys was carried out on the Santa Venera area, a site selected to build a car parking. High-density and high-resolution cross-correlated geophysical surveys were carried out in different parts of the area to better resolve the structures. Systematic excavations confirmed the clues suggested by geophysical prospecting about the presence of archaeological remains such as walls, canals and tombs. By the use of non-destructive geophysical techniques a two-fold aim was reached: to properly plan the building of the infrastructure and preserve the ancient artefacts according to the advanced European guidelines on the protection of archaeological heritage.

  3. Application of Laser Imaging for Bio/geophysical Studies

    NASA Technical Reports Server (NTRS)

    Hummel, J. R.; Goltz, S. M.; Depiero, N. L.; Degloria, D. P.; Pagliughi, F. M.

    1992-01-01

    SPARTA, Inc. has developed a low-cost, portable laser imager that, among other applications, can be used in bio/geophysical applications. In the application to be discussed here, the system was utilized as an imaging system for background features in a forested locale. The SPARTA mini-ladar system was used at the International Paper Northern Experimental Forest near Howland, Maine to assist in a project designed to study the thermal and radiometric phenomenology at forest edges. The imager was used to obtain data from three complex sites, a 'seed' orchard, a forest edge, and a building. The goal of the study was to demonstrate the usefulness of the laser imager as a tool to obtain geometric and internal structure data about complex 3-D objects in a natural background. The data from these images have been analyzed to obtain information about the distributions of the objects in a scene. A range detection algorithm has been used to identify individual objects in a laser image and an edge detection algorithm then applied to highlight the outlines of discrete objects. An example of an image processed in such a manner is shown. Described here are the results from the study. In addition, results are presented outlining how the laser imaging system could be used to obtain other important information about bio/geophysical systems, such as the distribution of woody material in forests.

  4. AAGRUUK: the Arctic Archive for Geophysical Research

    NASA Astrophysics Data System (ADS)

    Johnson, P. D.; Edwards, M. H.; Wright, D.; Dailey, M.

    2005-12-01

    The key to developing and maintaining a unified community database lies in building and supporting a general organizational structure linking distributed databases through the worldwide web via a portal that contains key information, links, and search engines, is maintained and updated by people familiar with the data sets, and contains sufficient information to be useful across many disciplines encompassed by research scientists. There must also be enough flexibility in the approach to support two disparate types of principal investigators who wish to contribute data: those who desire or require relinquishing their data to a repository managed by others and those who wish to maintain control of their data and online archives. To provide this flexibility and accommodate the diversity, volume, and complexity of multidisciplinary geological and geophysical data for the Arctic Ocean we are developing AAGRUUK, an online data repository combined with a web-based archive-linking infrastructure to produce a distributed Data Management System. The overarching goal of AAGRUUK is to promote collaborative research and multidisciplinary studies and foster new scientific insights for the Arctic Basin. To date the archive includes bathymetry, sidescan and subbottom data collected by the nuclear-powered submarines during the Science Ice Exercises (SCICEX), multibeam bathymetry collected by the USCGC HEALY and the Nathaniel B. Palmer, plus near-shore data around Barrow, Alaska as well as ice camp T3 and nuclear submarine soundings. Integration of the various bathymetric datasets has illustrated a number of problems, some of which aren't readily apparent until multiple overlapping datasets have been combined. Foremost among these are sounding errors caused by mapping while breaking ice and navigational misalignments in the SCICEX data. The former error is apparent in swath data that follow an irregular navigational track, indicating that a ship was unable to proceed directly from

  5. 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

  6. 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.

  7. 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.

  8. Geophysical approaches applied in the ancient theatre of Demetriada, Volos

    NASA Astrophysics Data System (ADS)

    Sarris, Apostolos; Papadopoulos, Nikos; Déderix, Sylviane; Salvi, Maria-Christina

    2013-08-01

    The city of Demetriada was constructed around 294-292 BC and became a stronghold of the Macedonian navy fleet, whereas in the Roman period it experienced significant growth and blossoming. The ancient theatre of the town was constructed at the same time with the foundation of the city, without being used for 2 centuries (1st ce. BC - 1st ce. A.D.) and being completely abandoned after the 4th ce. A.D., to be used only as a quarry for extraction of building material for Christian basilicas in the area. The theatre was found in 1809 and excavations took place in various years since 1907. Geophysical approaches were exploited recently in an effort to map the subsurface of the surrounding area of the theatre and help the reconstruction works of it. Magnetic gradiometry, Ground Penetrating Radar (GPR) and Electrical Resistivity Tomogrpahy (ERT) techniques were employed for mapping the area of the orchestra and the scene of the theatre, together with the area extending to the south of the theatre. A number of features were recognized by the magnetic techniques including older excavation trenches and the pilar of the stoa of the proscenium. The different occupation phases of the area have been manifested through the employment of tomographic and stratigraphic geophysical techniques like three-dimensional ERT and GPR. Architectural orthogonal structures aligned in a S-N direction have been correlated to the already excavated buildings of the ceramic workshop. The workshop seems to expand in a large section of the area which was probably constructed after the final abandonment of the theatre.

  9. 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.

  10. 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

  11. 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.

  12. Using seismology for regional confidence building

    SciTech Connect

    Nakanishi, K.K.

    1997-03-01

    Confidence building between regional parties can be facilitated through cooperative seismological research activities. Shared data, facilities, technology, and research results can (1) assure participants that nuclear testing is not taking place, (2) provide information that can be used to characterize the geophysical parameters of a region for earthquake hazard mitigation, and (3) support basic seismic research.

  13. 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.

  14. 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.

  15. Geophysics applications in critical zone science: emerging topics

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. 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.

  17. Geophysical monitoring in a hydrocarbon reservoir

    NASA Astrophysics Data System (ADS)

    Caffagni, Enrico; Bokelmann, Goetz

    2016-04-01

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

  18. 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

  19. 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

  20. 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

  1. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical... CORPORATION FREEDOM OF INFORMATION ACT Exemptions From Public Access to Corporation Records § 902.59 Geological and geophysical information. Any geological or geophysical information and data (including...

  2. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Geological and geophysical... CORPORATION FREEDOM OF INFORMATION ACT Exemptions From Public Access to Corporation Records § 902.59 Geological and geophysical information. Any geological or geophysical information and data (including...

  3. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Geological and geophysical... CORPORATION FREEDOM OF INFORMATION ACT Exemptions From Public Access to Corporation Records § 902.59 Geological and geophysical information. Any geological or geophysical information and data (including...

  4. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Geological and geophysical... CORPORATION FREEDOM OF INFORMATION ACT Exemptions From Public Access to Corporation Records § 902.59 Geological and geophysical information. Any geological or geophysical information and data (including...

  5. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Geological and geophysical... CORPORATION FREEDOM OF INFORMATION ACT Exemptions From Public Access to Corporation Records § 902.59 Geological and geophysical information. Any geological or geophysical information and data (including...

  6. Ninety Years of International Cooperation in Geophysics

    NASA Astrophysics Data System (ADS)

    Ismail-Zadeh, A.; Beer, T.

    2009-05-01

    Because applicable physical, chemical, and mathematical studies of the Earth system must be both interdisciplinary and international, the International Union of Geodesy and Geophysics (IUGG) was formed in 1919 as an non-governmental, non-profit organization dedicated to advancing, promoting, and communicating knowledge of the Earth system, its space environment, and the dynamical processes causing change. The Union brings together eight International Associations that address different disciplines of Earth sciences. Through these Associations, IUGG promotes and enables studies in the geosciences by providing a framework for collaborative research and information exchange, by organizing international scientific assemblies worldwide, and via research publications. Resolutions passed by assemblies of IUGG and its International Associations set geophysical standards and promote issues of science policy on which national members agree. IUGG has initiated and/or vigorously supported collaborative international efforts that have led to highly productive worldwide interdisciplinary research programs, such as the International Geophysical Year and subsequent International Years (IPY, IYPE, eGY, and IHY), International Lithosphere Programme, World Climate Research Programme, Geosphere-Biosphere Programme, and Integrated Research on Risk Disaster. IUGG is inherently involved in the projects and programs related to climate change, global warming, and related environmental impacts. One major contribution has been the creation, through the International Council for Science (ICSU), of the World Data Centers and the Federation of Astronomical and Geophysical Data Analysis Services. These are being transformed to the ICSU World Data System, from which the data gathered during the major programs and data products will be available to researchers everywhere. IUGG cooperates with UNESCO, WMO, and some other U.N. and non-governmental organizations in the study of natural catastrophes

  7. Geophysical techniques applied to urban planning in complex near surface environments. Examples of Zaragoza, NE Spain

    NASA Astrophysics Data System (ADS)

    Pueyo-Anchuela, Ó.; Casas-Sainz, A. M.; Soriano, M. A.; Pocoví-Juan, A.

    Complex geological shallow subsurface environments represent an important handicap in urban and building projects. The geological features of the Central Ebro Basin, with sharp lateral changes in Quaternary deposits, alluvial karst phenomena and anthropic activity can preclude the characterization of future urban areas only from isolated geomechanical tests or from non-correctly dimensioned geophysical techniques. This complexity is here analyzed in two different test fields, (i) one of them linked to flat-bottomed valleys with irregular distribution of Quaternary deposits related to sharp lateral facies changes and irregular preconsolidated substratum position and (ii) a second one with similar complexities in the alluvial deposits and karst activity linked to solution of the underlying evaporite substratum. The results show that different geophysical techniques allow for similar geological models to be obtained in the first case (flat-bottomed valleys), whereas only the application of several geophysical techniques can permit to correctly evaluate the geological model complexities in the second case (alluvial karst). In this second case, the geological and superficial information permit to refine the sensitivity of the applied geophysical techniques to different indicators of karst activity. In both cases 3D models are needed to correctly distinguish alluvial lateral sedimentary changes from superimposed karstic activity.

  8. Experiments to Detect Clandestine Graves from Interpreted High Resolution Geophysical Anomalies

    NASA Astrophysics Data System (ADS)

    Molina, C. M.; Hernandez, O.; Pringle, J.

    2013-05-01

    This project refers to the search for clandestine sites where possibly missing people have been buried based on interpreted near surface high resolution geophysical anomalies. Nowadays, there are thousands of missing people around the world that could have been tortured and killed and buried in clandestine graves. This is a huge problem for their families and governments that are responsible to warranty the human rights for everybody. These people need to be found and the related crime cases need to be resolved. This work proposes to construct a series of graves where all the conditions of the grave, human remains and related objects are known. It is expected to detect contrasting physical properties of soil to identify the known human remains and objects. The proposed geophysical methods will include electrical tomography, magnetic and ground penetrating radar, among others. Two geographical sites will be selected to located and build standard graves with contrasting weather, soil, vegetation, geographic and geologic conditions. Forward and inverse modeling will be applied to locate and enhance the geophysical response of the known graves and to validate the methodology. As a result, an integrated geophysical program will be provided to support the search for clandestine graves helping to find missing people that have been illegally buried. Optionally, the methodology will be tested to search for real clandestine graves.

  9. The World Data Fabric: A New Concept for Geophysical Data Collection and Dissemination

    NASA Astrophysics Data System (ADS)

    Papitashvili, V.; Papitashvili, N.

    2005-12-01

    copiers; and (c) the WDF datasets must be protected from deliberate corruption or hacking. As the WDF (for all or specific geophysical disciplines) is established and actively maintained by a series of policies and regulations (i.e., specific for a particular discipline) through the WDC activities, then one can write a specific middleware to retrieve required data from the ``data fabric'', building then either the specific Virtual Observatory or Distributed Data System. The presentation will address these challenges suggesting some immediate and intervening solutions.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Geophysical data are increasingly used to construct groundwater models. Such data are collected at lower cost and much higher density than the traditionally used geological, hydraulic, and hydrological data. The geophysical data are often inverted independently and used together with geological data to build the conceptual model and define the parameterization of the groundwater model. The groundwater model is then calibrated against hydrological measurements only. This sequential inversion approach process is relatively straightforward; however it fails to extract all of the relevant information contained in the data. Previous researchers have shown examples for which joint or coupled hydrogeophysical inversion leads to improved use of geophysical and hydrological data. However, to date there are no clear guidelines for when sequential, joint, or coupled inversion should be used. We present a modeling platform that can be used to examine the conditions that support the use of each inversion approach for efficient and effective use of all data to constrain hydrologic models. We have developed a synthetic "test-bench environment" to test the advantages and limitations of alternative hydrogeophysical inversion approaches. The environment consists of multiple high resolution realizations of synthetic hydrogeological and geophysical systems (called true systems). The two types of true systems can be used together with corresponding forward codes to generate hydrological and geophysical data sets, respectively. There is also complete flexibility in the choice of relationships between hydraulic and geophysical properties. Noise can be added to the synthetic hydrologic and geophysical data sets and these exhaustive data sets can be down sampled to represent realistic data sets of varying measurement density and coverage. Finally, these synthetic data sets can be interpreted using any hydrogeophysical inversion scheme and the resulting predictions can be compared with

  11. Building Awareness.

    ERIC Educational Resources Information Center

    Meilach, Dona Z.

    2001-01-01

    Discusses the importance of developing students' building awareness by exploring logos, or buildings that symbolize a country, to learn about architecture and the cultures in different countries. Explores categories of buildings. Includes examples of logos from around the world. (CMK)

  12. Geophysical methods for road construction and maintenance

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    SciTech Connect

    GV Last; DG Horton

    2000-03-23

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

  14. Sessions on history of space and geophysics spark interest

    NASA Astrophysics Data System (ADS)

    Schröder, Wilfried

    Three sessions at international conferences were held in 1997 to discuss the history of space and geophysics and its different disciplines. The first session was held during the Assembly of the German Geophysical Society in March in Potsdam, Germany. Topics included the theory of relativity and gravitation in geophysics; work by Albert Abraham Michelson, Leon Foucault, and Ernst Mach; work by Hermann von Helmholtz; and the physical application and geophysical evidence of Werner Heisenberg's research. Also included were discussions relevant to the history of geophysics, aeronomy, meteor astronomy, and geodetical research, including developments in instrumentation during the last few decades.

  15. The Geophysical Fluid Flow Cell Experiment

    NASA Technical Reports Server (NTRS)

    Hart, J. E.; Ohlsen, D.; Kittleman, S.; Borhani, N.; Leslie, F.; Miller, T.

    1999-01-01

    The Geophysical Fluid Flow Cell (GFFC) experiment performed visualizations of thermal convection in a rotating differentially heated spherical shell of fluid. In these experiments dielectric polarization forces are used to generate a radially directed buoyancy force. This enables the laboratory simulation of a number of geophysically and astrophysically important situations in which sphericity and rotation both impose strong constraints on global scale fluid motions. During USML-2 a large set of experiments with spherically symmetric heating were carried out. These enabled the determination of critical points for the transition to various forms of nonaxisymmetric convection and, for highly turbulent flows, the transition latitudes separating the different modes of motion. This paper presents a first analysis of these experiments as well as data on the general performance of the instrument during the USML-2 flight.

  16. Earth Rotational Variations Excited by Geophysical Fluids

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

    Modern space geodetic measurement of Earth rotation variations, particularly by means of the VLBI technique, has over the years allowed studies of Earth rotation dynamics to advance in ever-increasing precision, accuracy, and temporal resolution. A review will be presented on our understanding of the geophysical and climatic causes, or "excitations". for length-of-day change, polar motion, and nutations. These excitations sources come from mass transports that constantly take place in the Earth system comprised of the atmosphere, hydrosphere, cryosphere, lithosphere, mantle, and the cores. In this sense, together with other space geodetic measurements of time-variable gravity and geocenter motion, Earth rotation variations become a remote-sensing tool for the integral of all mass transports, providing valuable information about the latter on a wide range of spatial and temporal scales. Future prospects with respect to geophysical studies with even higher accuracy and resolution will be discussed.

  17. Geophysical and atmospheric evolution of habitable planets.

    PubMed

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

    2010-01-01

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

  18. The geophysical impact of the Aristoteles mission

    NASA Astrophysics Data System (ADS)

    Anderson, Allen Joel; Klingele, E.; Sabadini, R.; Tinti, S.; Zerbini, Suzanna

    1991-12-01

    The importance of a precise, high resolution gradiometric and magnetometric mission in some topics of geophysical interest is stressed. Ways in which the planned Aristoteles mission can allow the geophysical community to improve the knowledge and the physical understanding of several important geodynamical processes involving the coupled system consisting of the lithosphere, asthenosphere and upper mantle are discussed. Particular attention is devoted to the inversion of anomalous density structures in collision and subduction zones by means of the joint use of gradiometric and seismic tomographic data. Some modeling efforts accomplished to study the capability of the mission to invert the rheological parameters of the lithosphere and upper mantle through the gravimetric signals of internal and surface density anomalies are described.

  19. Geophysical methods for monitoring infiltration in soil

    NASA Astrophysics Data System (ADS)

    Coquet, Yves; Pessel, Marc; Saintenoy, Albane

    2015-04-01

    Geophysics provides useful tools for monitoring water infiltration in soil essentially because they are non-invasive and have a good time-resolution. We present some results obtained on different soils using two geophysical techniques: electrical resistivity tomography (ERT) and ground-penetrating radar (GPR). Infiltration in a loamy soil was monitored using a 2D Wenner array set up under a tension disc infiltrometer. A good imaging of the infiltration bulb below the infiltrometer could be achieved provided a sufficient resistivity contrast between the wet and the dry soil zones. ERT data could be used to invert soil hydraulic properties. However, we found that the information provided by the ERT could be of limited importance in regard to the information provided by the infiltration rate dynamics if the ERT spatial resolution is not small enough to capture the details of the infiltration front at the limit between the wet and dry soil zones. GPR was found to be a good tool to monitor the progression of the infiltration front in a sandy soil. By combining a water transport simulation model (HYDRUS-1D), a method for transforming water content into dielectric permittivity values (CRIM), and an electromagnetic wave propagation model (GprMax), the Mualem-van Genuchten hydraulic parameters could be retrieved from radargrams obtained under constant or falling head infiltration experiments. Both ERT and GPR methods have pros and cons. Time and spatial resolutions are of prime importance to achieve a sufficient sensitivity to all soil hydraulic parameters. Two exploration fields are suggested: the combination of different geophysical methods to explore infiltration in heterogeneous soils, and the development of integrated infiltrometers that allow geophysical measurements while monitoring water infiltration rate in soil.

  20. FY97 Geophysics Technology Area Plan.

    DTIC Science & Technology

    1997-03-01

    example, Seeker and Missile Simulations technology will be developed to make theater (DISAMS). This plan has been reviewed by all Air Force laboratory ...INDUSTRIAL RESEARCH AND Geophysics is a pervasive technology that directly DEVELOPMENT (IRAD): A comparison of the interacts with all of the other Air Force ...radiation belt models roadmaps that contain research programs underway has been halted. and planned by the Air Force and National Aeronau- 0 The design of

  1. Monitoring Global Geophysical Fluids by Space Geodesy

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  2. Application of geophysical methods for fracture characterization

    SciTech Connect

    Lee, K.H.; Majer, E.L.; McEvilly, T.V. |; Morrison, H.F. |

    1990-01-01

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

  3. Identification and Description of Geophysical Techniques.

    DTIC Science & Technology

    1980-11-01

    for reaction with groundwater and pollutants. Shales and clays, for example, have the po- tential for concentrating certain ions by the processes of...8217tured shale unit. Geophysical expression of lithology can include acoustic velocity, electrical resistivity, spontaneous potential, density, gamma...the travel time required for acoustic compressional waves, generated in the earth by a near-surface explosion, mechanical impact, or vibration , to

  4. Some geologic observations concerning lunar geophysical models

    NASA Technical Reports Server (NTRS)

    Head, J. W.

    1977-01-01

    The distribution of lunar geologic units in space and time and their mode of origin were considered since they provided significant data which bear on a number of current problems in lunar geophysics. Observations and problems were discussed which deal with the characterization of the upper 25 km of the lunar crust, the tectonic style of the crust, the formation of mascons within major basins, analysis of lunar magnetic anomalies, and the history of the lunar crust.

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

    PubMed Central

    2016-01-01

    This article discusses the role of geophysical fluid dynamics (GFD) in understanding the natural environment, and in particular the dynamics of atmospheres and oceans on Earth and elsewhere. GFD, as usually understood, is a branch of the geosciences that deals with fluid dynamics and that, by tradition, seeks to extract the bare essence of a phenomenon, omitting detail where possible. The geosciences in general deal with complex interacting systems and in some ways resemble condensed matter physics or aspects of biology, where we seek explanations of phenomena at a higher level than simply directly calculating the interactions of all the constituent parts. That is, we try to develop theories or make simple models of the behaviour of the system as a whole. However, these days in many geophysical systems of interest, we can also obtain information for how the system behaves by almost direct numerical simulation from the governing equations. The numerical model itself then explicitly predicts the emergent phenomena—the Gulf Stream, for example—something that is still usually impossible in biology or condensed matter physics. Such simulations, as manifested, for example, in complicated general circulation models, have in some ways been extremely successful and one may reasonably now ask whether understanding a complex geophysical system is necessary for predicting it. In what follows we discuss such issues and the roles that GFD has played in the past and will play in the future. PMID:27616918

  6. Using geophysics to characterize levee stability

    NASA Astrophysics Data System (ADS)

    Dalton, Laura M.

    Shallow slough slides have occurred along the river side slope of Mississippi River Levees for over sixty years. Shallow slough slides also occur along smaller levees that protect tributaries of the Mississippi River. This investigation takes place along a section of the Coldwater River Levee, a tributary levee of the Mississippi River. Field observation, soil samples, and geophysical data were collected at two field sites located on the border of Tate and Tunica County, MS. The first site consists of a developed shallow slough slide that had occurred that has not yet been repaired and the second site is a potential slide area. Electromagnetic induction and electrical resistivity tomography were the geophysical methods used to define subsurface conditions that make a levee vulnerable to failure. These electrical methods are sensitive to the electrical conductivity of the soil and therefore depend upon: soil moisture, clay content, pore size distribution as well as larger scale structures at depth such as cracks and fissures. These same physical properties of the soil are also important to assessing the vulnerability of a levee to slough slides. Soil tests and field observations were also implemented in this investigation to describe and classify the soil composition of the levee material. The problem of slough slide occurrence can potentially be reduced if vulnerabilities are located with the help of geophysical techniques.

  7. Mass Transport in Global Geophysical Fluids

    NASA Technical Reports Server (NTRS)

    Chao, B. F.

    1999-01-01

    Mass transports occurring in the atmosphere-hydrosphere-solid Earth-core system (the "global geophysical fluids") are important geophysical phenomena. They occur on all temporal and spatial scales. Examples include air mass and ocean circulations, tides, hydrological water redistribution, mantle processes such as post-glacial rebound, earthquakes and tectonic motions, and core geodynamo activities. With only a few exceptions on the Earth surface, the temporal history and spatial pattern of such mass transport are often not amenable to direct observations. Space geodesy techniques, however, have the capability of monitoring certain direct consequences of the mass transport, including Earth's rotation variations, gravitational field variations, and the geocenter motion. These techniques include the very-long-baseline interferometry, satellite laser ranging and Doppler tracking, and the Global Positioning System, all entail global observational networks. While considerable advances have been made in observing and understanding of the dynamics of Earth's rotation, only the lowest-degree gravitational variations have been observed and limited knowledge of geocenter motion obtained. New space missions, projects and initiatives promise to further improve the measurements and hence our knowledge about the global mass transports. The latter contributes to our understanding and modeling capability of the geophysical processes that produce and regulate the mass transports, as well as the solid Earth's response to such changes in constraining the modeling of Earth's mechanical properties.

  8. Polarimetric remote sensing of geophysical medium structures

    NASA Astrophysics Data System (ADS)

    Nghiem, S. V.; Yueh, S. H.; Kwok, R.; Nguyen, D. T.

    1993-11-01

    Polarimetric remote sensing of structures in geophysical media is studied in this paper based on their symmetry properties. Orientations of spheroidal scatterers described by spherical, uniform, planophile, plagiothile, erectophile, and extremophile distributions are considered to derive their polarimetric backscattering characteristics. These distributions can be identified from the observed scattering coefficients by comparison with theoretical symmetry calculations. A new parameter is defined to study scattering structures in geophysical media. Experimental observations from polarimetric data acquired by the Jet Propulsion Laboratory airborne synthetic aperture radar over forests, sea ice, and sea surface are presented to illustrate the use of symmetry properties. For forests, the coniferous forest in Mount Shasta area and mixed forests near Presque Isle show evidence of the centrical symmetry at C band. In sea ice from the Beaufort Sea, multiyear sea ice has a cross-polarized ratio e close to e0, calculated from symmetry, due to the randomness in the scattering structure. For first-year sea ice, e is much smaller than e0 as a result of preferential alignment of the columnar structure of the ice. From polarimetric data of a sea surface in the Bering sea, it is observed that e and e0 are increasing with incident angle and e is greater than e0 at L band because of the directional feature of sea surface waves. Use of symmetry properties of geophysical media for polarimetric radar calibration is also suggested.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

    Vallis, Geoffrey K.

    2016-08-01

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

  11. Cluster analysis applied to multiparameter geophysical dataset

    NASA Astrophysics Data System (ADS)

    Di Giuseppe, M. G.; Troiano, A.; Troise, C.; De Natale, G.

    2012-04-01

    Multi-parameter acquisition is a common geophysical field practice nowadays. Regularly seismic velocity and attenuation, gravity and electromagnetic dataset are acquired in a certain area, to obtain a complete characterization of the some investigate feature of the subsoil. Such a richness of information is often underestimated, although an integration of the analysis could provide a notable improving in the imaging of the investigated structures, mostly because the handling of distinct parameters and their joint inversion still presents several and severe problems. Post-inversion statistical techniques represent a promising approach to these questions, providing a quick, simple and elegant way to obtain this advantageous but complex integration. We present an approach based on the partition of the analyzed multi parameter dataset in a number of different classes, identified as localized regions of high correlation. These classes, or 'Cluster', are structured in such a way that the observations pertaining to a certain group are more similar to each other than the observations belonging to a different one, according to an optimal logical criterion. Regions of the subsoil sharing the same physical characteristic are so identified, without a-priori or empirical relationship linking the distinct measured parameters. The retrieved imaging results highly affordable in a statistical sense, specifically due to this lack of external hypothesis that are, instead, indispensable in a full joint inversion, were works, as matter of fact, just a real constrain for the inversion process, not seldom of relative consistence. We apply our procedure to a certain number of experimental dataset, related to several structures at very different scales presents in the Campanian district (southern Italy). These structures goes from the shallows evidence of the active fault zone originating the M 7.9 Irpinia earthquake to the main feature characterizing the Campi Flegrei Caldera and the Mt

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  13. The Virtual Exploratorium: Connecting Student-constructed Visualization to Fundamental Geophysical Principles

    NASA Astrophysics Data System (ADS)

    Pandya, R.; Bramer, D.; Elliott, D.; Hay, K.; Marlino, M.; Middleton, D.; Ramamurthy, M.; Scheiltin, T.; Wilhelmson, R.

    2001-05-01

    The Virtual Exploratorium (VE) is a web-based inquiry environment in which learners use authentic data sets and scientific tools to build their own visualizations of geophysical phenomena. Learner-constructed visualizations not only give the learner a more robust conception than passive visualization; they can also guide inquiry toward fundamental physical principles. In the VE, learners will explore these fundamental physical principles using concept models. Concept models are Java-based applications for discovering fundamental principles in simplified and idealized settings. Learners will use probes to connect the principles they discover to the complex geophysical phenomenon they visualized. Probes are similar to the concept models, except that they respond to the environment of the student-constructed visualization rather than simplified idealized environments. The probes help learners contextualize the fundamental principles and bridge the gap between complex realistic visualization with multiple processes and the handful of underlying physical principles common across the geosciences.

  14. Evolution of neural networks for the prediction of hydraulic conductivity as a function of borehole geophysical logs: Shobasama site, Japan.

    SciTech Connect

    Reeves, Paul C.; McKenna, Sean Andrew

    2004-06-01

    This report describes the methodology and results of a project to develop a neural network for the prediction of the measured hydraulic conductivity or transmissivity in a series of boreholes at the Tono, Japan study site. Geophysical measurements were used as the input to EL feed-forward neural network. A simple genetic algorithm was used to evolve the architecture and parameters of the neural network in conjunction with an optimal subset of geophysical measurements for the prediction of hydraulic conductivity. The first attempt was focused on the estimation of the class of the hydraulic conductivity, high, medium or low, from the geophysical logs. This estimation was done while using the genetic algorithm to simultaneously determine which geophysical logs were the most important and optimizing the architecture of the neural network. Initial results showed that certain geophysical logs provided more information than others- most notably the 'short-normal', micro-resistivity, porosity and sonic logs provided the most information on hydraulic conductivity. The neural network produced excellent training results with accuracy of 90 percent or greater, but was unable to produce accurate predictions of the hydraulic conductivity class. The second attempt at prediction was done using a new methodology and a modified data set. The new methodology builds on the results of the first attempts at prediction by limiting the choices of geophysical logs to only those that provide significant information. Additionally, this second attempt uses a modified data set and predicts transmissivity instead of hydraulic conductivity. Results of these simulations indicate that the most informative geophysical measurements for the prediction of transmissivity are depth and sonic log. The long normal resistivity and self potential borehole logs are moderately informative. In addition, it was found that porosity and crack counts (clear, open, or hairline) do not inform predictions of

  15. Linking Geophysical Networks to International Economic Development Through Integration of Global and National Monitoring

    NASA Astrophysics Data System (ADS)

    Lerner-Lam, A.

    2007-05-01

    Outside of the research community and mission agencies, global geophysical monitoring rarely receives sustained attention except in the aftermath of a humanitarian disaster. The recovery and rebuilding period focuses attention and resources for a short time on regional needs for geophysical observation, often at the national or sub-national level. This can result in the rapid deployment of national monitoring networks, but may overlook the longer-term benefits of integration with global networks. Even in the case of multinational disasters, such as the Indian Ocean tsunami, it has proved difficult to promote the integration of national solutions with global monitoring, research and operations infrastructure. More importantly, continuing operations at the national or sub-national scale are difficult to sustain once the resources associated with recovery and rebuilding are depleted. Except for some notable examples, the vast infrastructure associated with global geophysical monitoring is not utilized constructively to promote the integration of national networks with international efforts. This represents a missed opportunity not only for monitoring, but for developing the international research and educational collaborations necessary for technological transfer and capacity building. The recent confluence of highly visible disasters, global multi-hazard risk assessments, evaluations of the relationships between natural disasters and socio-economic development, and shifts in development agency policies, provides an opportunity to link global geophysical monitoring initiatives to central issues in international development. Natural hazard risk reduction has not been the first priority of international development agendas for understandable, mainly humanitarian reasons. However, it is now recognized that the so-called risk premium associated with making development projects more risk conscious or risk resilient is relatively small relative to potential losses. Thus

  16. Global Geophysical Fluids Center of IERS

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    The Global Geophysical Fluids Center (GGFC) and its seven Special Bureaus (SB, for Atmosphere, Oceans, Tides, Hydrology, Mantle, Core and Gravity/Geocenter) were establishes by the International Earth Rotation Service in 1998, to support global geodynamic research. Mass transports in the geophysical fluids of the Earth system will cause observable geodynamic effects on a broad time scale.These include (1) variations in the solid Earth's rotation (in length-of-day and polar motion/nutation) via the conservation of angular momentum and effected by torques at the fluid-solid Earth interface; (2) changes in the global gravitational field according to Newton's gravitational law; and (3) motion in the center of mass of the solid Earth relative to that of the whole Earth ("geocenter") via the conservation of linear momentum. These minute signals have become observable by space geodetic techniques, primarily VLBI, SLR, GPS, and DORIS, and new exciting data will be available by space gravity, altimetry, SAR, and magnetic missions. In this sense the precise space geodetic techniques have become effective means of remote sensing of global mass transports. The GGFC and its SBs have the responsibility of supporting, facilitating, and providing services to the worldwide research community in the related research areas. We compute, analyze, compare, archive, and disseminate the time series of the angular momenta and the related torques, gravitational coefficients, and geocenter shift for all geophysical fluids, based on global observational data, and/or products from state-of-the-art models some of which assimilate such data. The computed quantities, algorithm and data formats are standardized. This paper reviews our activities, reports the status, and looks forward into the future.

  17. 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

  18. Field studies in geophysical diffraction tomography

    SciTech Connect

    Witten, A.J.; Stevens, S.S. ); King, W.C. . Dept. of Geography and Environmental Engineering); Ursic, J.R. . Region V)

    1992-01-01

    Geophysical diffraction tomography (GDT) is a quantitative, high- resolution technique for subsurface imaging. This method has been used in a number of shallow applications to image buried waste, trenches, soil strata, tunnels, synthetic magma chambers, and the buried skeletal remains of seismosaurus, the longest dinosaur ever discovered. The theory associated with the GDT inversion and implementing software have been developed for acoustic and scalar electromagnetic waves for bistatic and monostatic measurements in cross-borehole, offset vertical seismic profiling and reflection geometries. This paper presents an overview of some signal processing algorithms, a description of the instrumentation used in field studies, and selected imaging results.

  19. Field studies in geophysical diffraction tomography

    SciTech Connect

    Witten, A.J.; Stevens, S.S.; King, W.C.; Ursic, J.R.

    1992-07-01

    Geophysical diffraction tomography (GDT) is a quantitative, high- resolution technique for subsurface imaging. This method has been used in a number of shallow applications to image buried waste, trenches, soil strata, tunnels, synthetic magma chambers, and the buried skeletal remains of seismosaurus, the longest dinosaur ever discovered. The theory associated with the GDT inversion and implementing software have been developed for acoustic and scalar electromagnetic waves for bistatic and monostatic measurements in cross-borehole, offset vertical seismic profiling and reflection geometries. This paper presents an overview of some signal processing algorithms, a description of the instrumentation used in field studies, and selected imaging results.

  20. 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

  1. Time-reversal methods in geophysics

    SciTech Connect

    Larmat, Carene S.; Guyer, Robert A.; Johnson, Paul A.

    2010-08-15

    Before the 20th century there were few seismometers. So Earth's dynamic geophysical processes were poorly understood. Today the potential for understanding those processes is enormous: The number of seismic instruments is continually increasing, their data are easily stored and shared, and computing power grows exponentially. As a result, seismologists are rapidly discovering new kinds of seismic signals in the frequency range 0.001-100 Hz, as well as relatively large nonseismic displacements, monitored by the global positioning system, occurring over days or weeks.

  2. Large natural geophysical events: planetary planning

    SciTech Connect

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

    1984-09-01

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

  3. 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.

  4. Surface exploration geophysics applied to the moon

    SciTech Connect

    Ander, M.E.

    1984-01-01

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

  5. 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.

  6. A fractured rock geophysical toolbox method selection tool

    USGS Publications Warehouse

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

    2016-01-01

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

  7. Building America

    SciTech Connect

    Brad Oberg

    2010-12-31

    IBACOS researched the constructability and viability issues of using high performance windows as one component of a larger approach to building houses that achieve the Building America 70% energy savings target.

  8. Inverse Problem;Litho_Inversion; Geology and Geophysics

    NASA Astrophysics Data System (ADS)

    Antonio, Guillen; Gabriel, Courrioux; Bernard, Bourgine

    2015-04-01

    Subsurface modeling is a key tool to describe, understand and quantify geological processes. As the subsurface is inaccessible and its observation is limited by acquisition methods, 3D models of the subsurface are usually built from the interpretation of sparse data with limited resolution. Therefore, uncertainties occur during the model building process, due to possible cognitive human biais, natural variability of geological objects and intrinsic uncertainties of data. In such context, the predictibility of models is limited by uncertainties, which must be assessed in order to reduce economical and human risks linked to the use of models. This work focuses more specifically on uncertainties about geological structures. In this context, a stochastic method is developed for generating structural models with various fault and horizon geometries as well as fault connections. Realistic geological objects are obtained using implicit modeling that represents a surface by an equipotential of a volumetric scalar field. Faults have also been described by a reduced set of uncertain parameters, which opens the way to the inversion of structural objects using geophysical data by baysian methods.

  9. 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

  10. Healthy Buildings?

    ERIC Educational Resources Information Center

    Grubb, Deborah

    Health problems related to school buildings can be categorized in five major areas: sick-building syndrome; health-threatening building materials; environmental hazards such as radon gas and asbestos; lead poisoning; and poor indoor air quality due to smoke, chemicals, and other pollutants. This paper provides an overview of these areas,…

  11. 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.

  12. New perspectives on superparameterization for geophysical turbulence

    NASA Astrophysics Data System (ADS)

    Majda, Andrew J.; Grooms, Ian

    2014-08-01

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

  13. Geophysical mapping of palsa peatland permafrost

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  14. Geophysical mapping of palsa peatland permafrost

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  15. Geophysics and cosmogony of solar system

    NASA Astrophysics Data System (ADS)

    Kuzjmenko, G. I.; Smirnov, V. A.

    2003-04-01

    The attention to primary importance of geophysics in formation of modern representations about planets of Solar system is inverted. [ Kuzjmenko G.I. Deep Processes in the Earth's Interior. Geophys. J. 2001. Vol. 20, pp 813 -831; Kuzjmenko G.I., Smirnov V.A. Minor Bodys and Cosmogony of a Solar System. CAMMAC 2002. Intern. Conf. September 23 - 29, Vinnitsia, 2002, pp 35 -36]. The analysis rocket given about electromagnetic properties of Solar system has helped utilization Generalized Statistical-Wavemechanical Equations (GSWE), which special case is the quantum equation of Schrödinger. From GSWE the decision not only old problems of Solar system, but also prediction of presence of a belt of small bodies of Kuiper's and features of absent-minded substance in Solar system follows. The modern geophysical data on properties of the Earth with use GSWE result not only in the description of the electromagnetic characteristics of planets, but open existence dark mattery, which properties now are actively studied [Kuzjmenko G.I., Zelinsky I.P. Generalized Statistical-Wavemechanical Equations (GSWE) and its Applications. Proc. of 16-th IMACS World Congress 2000. Lausanne, Switzerland, August 21-25, 2000. CD File 416 -1].

  16. Diversity of threshold phenomena in geophysical media

    NASA Astrophysics Data System (ADS)

    Guglielmi, A. V.

    2017-01-01

    The sample analysis of threshold phenomena in the lithosphere, atmosphere, and magnetosphere is conducted. The phenomena due to the flow of electric current and pore fluid in the rocks are considered, the scenario of wind-driven generation of atmospheric electricity is suggested, and the model of the geomagnetic storm time Dst variation is analyzed. An important general conclusion consists in the fact that in the geophysical media there is a wide class of threshold phenomena that are affine with phase transitions of the second kind. These phenomena are also related to the critical transitions in self-oscillatory systems with soft self-excitation. The integral representation of bifurcation diagrams for threshold phenomena is suggested. This provides a simple way to take into account the influence of the fluctuations on the transition of a system through the threshold. Fluctuations remove singularity at the threshold point and, generally, lead to a certain shifting of the threshold. The question concerning the hard transition through the threshold and several aspects of modeling the blow-up instability which is presumed to occasionally develop in the geophysical media are discussed.

  17. New perspectives on superparameterization for geophysical turbulence

    SciTech Connect

    Majda, Andrew J.; Grooms, Ian

    2014-08-15

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

  18. Geophysical Limitations on the Habitable Zone

    NASA Astrophysics Data System (ADS)

    Noack, L.; Van Hoolst, T.

    2015-10-01

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

  19. Field implementation of geophysical diffraction tomography

    SciTech Connect

    Witten, A.J.; Stevens, S.S.

    1984-01-01

    Geophysical diffraction tomography is a new technique that shows promise as a tool for quantitative subsurface (below-ground) imaging. The approach being used is based upon the filtered backpropagation algorithm, which is a mathematical extension of the reconstruction software used in conventional X-ray CAT scanners. The difference between this method and existing methods is that the new algorithm rigorously accounts for diffraction effects through an exact inversion of the wave equation. This refinement is necessary in that it admits the use of acoustic and long-wavelength electromagnetic waves, allowing tomography to be taken from the laboratory to the field. ORNL's effort in geophysical diffraction tomography involves reducing the filtered backpropagation algorithm to practice. This requires the design and construction of field instrumentation as well as the development of an improved algorithm. The original algorithm requires the imaged region to be illuminated by plane waves. This requirement simplifies the algorithm but complicates its field implementation in that plane waves are difficult to generate. Consequently, ORNL has been working to generalize the filtered backpropagation algorithm to allow a broader range of incoming wave fields which can more easily be realized in the field. The instrumentation aspects involve the selection of appropriate sonic sources and receivers along with the development of a state-of-art, portable, computer-controlled, multichannel data acquisition system. 5 references, 6 figures.

  20. Minimax approach to inverse problems of geophysics

    NASA Astrophysics Data System (ADS)

    Balk, P. I.; Dolgal, A. S.; Balk, T. V.; Khristenko, L. A.

    2016-03-01

    A new approach is suggested for solving the inverse problems that arise in the different fields of applied geophysics (gravity, magnetic, and electrical prospecting, geothermy) and require assessing the spatial region occupied by the anomaly-generating masses in the presence of different types of a priori information. The interpretation which provides the maximum guaranteed proximity of the model field sources to the real perturbing object is treated as the best interpretation. In some fields of science (game theory, economics, operations research), the decision-making principle that lies in minimizing the probable losses which cannot be prevented if the situation develops by the worst-case scenario is referred to as minimax. The minimax criterion of choice is interesting as, instead of being confined to the indirect (and sometimes doubtful) signs of the "optimal" solution, it relies on the actual properties of the information in the results of a particular interpretation. In the hierarchy of the approaches to the solution of the inverse problems of geophysics ordered by the volume and quality of the retrieved information about the sources of the field, the minimax approach should take special place.

  1. 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

  2. Using Grand Challenges For Innovative Teaching in Structural Geology, Geophysics, and Tectonics

    NASA Astrophysics Data System (ADS)

    McDaris, J. R.; Tewksbury, B. J.; Wysession, M. E.

    2012-12-01

    An innovative approach to teaching involves using the "Big Ideas" or "Grand Challenges" of a field, as determined by the research community in that area, as the basis for classroom activities. There have been several recent efforts in the areas of structural geology, tectonics, and geophysics to determine these Grand Challenges, including the areas of seismology ("Seismological Grand Challenges in Understanding Earth's Dynamic Systems"), mineral physics ("Unlocking the Building Blocks of the Planet"), EarthScope-related science ("Unlocking the Secrets of the North American Continent: An EarthScope Science Plan for 2010-2020"), and structural geology and tectonics (at the Structural Geology and Tectonics Forum held at Williams College in June, 2012). These research community efforts produced frameworks of the essential information for their fields with the aim of guiding future research. An integral part of this, however, is training the next generation of scientists, and using these Big Ideas as the basis for course structures and activities is a powerful way to make this happen. When activities, labs, and homeworks are drawn from relevant and cutting-edge research topics, students can find the material more fascinating and engaging, and can develop a better sense of the dynamic process of scientific discovery. Many creative ideas for incorporating the Grand Challenges of structural geology, tectonics, and geophysics in the classroom were developed at a Cutting Edge workshop on "Teaching Structural Geology, Geophysics, and Tectonics in the 21st Century" held at the University of Tennessee in July, 2012.

  3. THE GERMAN NORTH SEA COAST IN FOCUS OF AIRBORNE GEOPHYSICAL INVESTIGATIONS

    NASA Astrophysics Data System (ADS)

    Steuer, A.; Siemon, B.; Schaumann, G.; Wiederhold, H.; Meyer, U.; Binot, F.; Kühne, K.

    2009-12-01

    In recent years airborne geophysical methods have turned out to have great potential in delineating subsurface information down to some hundred meters depth. This information is essential for planning purposes for manifold geoscientific, economic or environmental questions, like, e.g., utilization and protection of freshwater resources, land utilization or industrial planning. These data integrated into a three-dimensional geographical information system provide a perfect tool for spatial planning. Beside the geologic or geophysical basic information also changes of surface and subsurface data in time and space may be documented by repeated surveys. Especially electromagnetic induction is the most versatile of the airborne geophysical methods and widely applied in hydrogeological investigations because the measurements respond to both lithologic and water-chemistry variations. The applications include geologic mapping and aquifer structure, delineation of soil and groundwater salinization, salt-water intrusion into coastal aquifers etc. Building on previous results and knowledge a general airborne survey of the German North Sea coastal area started in 2008. Emphasis is placed on the mapping of fresh-/saltwater interfaces (e.g., North Sea island Borkum), saltwater intrusions and the evaluation of the coastal aquifers (e.g., Elbe estuary) as well as on the mapping of submarine freshwater occurrence (e.g., Langeoog, Wadden Sea). With the mapping a basis for monitoring should be set up.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Geophysical subsurface imaging and interface identification.

    SciTech Connect

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

    2005-09-01

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

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

    SciTech Connect

    Daniels, Jeff

    2012-11-30

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

  10. Natural hazards activities of the National Geophysical Data Center

    USGS Publications Warehouse

    Lockridge, P.A.

    1985-01-01

    The National Geophysical Data Center (NGDC), a part of the National Oceanic and Atmospheric Administration, has been given the task of collecting, managing, and disseminating the great mass of inofmation produced by scientific observations of the geophysical environment. This article describes NGDC data bases that speifically relate to natural hazards. 

  11. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2-1 Geophysical exploration. Geophysical exploration in Special Tar Sand Areas shall be governed by part 3150 of this title. Information obtained under a permit shall...

  12. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2-1 Geophysical exploration. Geophysical exploration in Special Tar Sand Areas shall be governed by part 3150 of this title. Information obtained under a permit shall...

  13. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2-1 Geophysical exploration. Geophysical exploration in Special Tar Sand Areas shall be governed by part 3150 of this title. Information obtained under a permit shall...

  14. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LEASING IN SPECIAL TAR SAND AREAS Leasing in Special Tar Sand Areas § 3141.2-1 Geophysical exploration. Geophysical exploration in Special Tar Sand Areas shall be governed by part 3150 of this title. Information obtained under a permit shall...

  15. Introduction to the JEEG Agricultural Geophysics special issue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent advancements such as the availability of personal computers, technologies to store/process large amounts of data, the GPS, and GIS have now made geophysical methods practical for agricultural use. Consequently, there has been a rapid expansion of agricultural geophysics research just over the...

  16. Application of geophysical methods to agriculture: An overview

    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...

  17. GENERAL CONSIDERATIONS FOR GEOPHYSICAL METHODS APPLIED TO AGRICULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Geophysics is the application of physical quantity measurement techniques to provide information on conditions or features beneath the earth’s surface. With the exception of borehole geophysical methods and soil probes like a cone penetrometer, these techniques are generally noninvasive with physica...

  18. Monitoring Vadose Zone Desiccation with Geophysical Methods

    SciTech Connect

    Truex, Michael J.; Johnson, Timothy C.; Strickland, Christopher E.; Peterson, John E.; Hubbard, Susan S.

    2013-05-01

    Soil desiccation was recently field tested as a potential vadose zone remediation technology. Desiccation removes water from the vadose zone and significantly decreases the aqueous-phase permeability of the desiccated zone, thereby decreasing movement of moisture and contaminants. The 2-D and 3-D distribution of moisture content reduction over time provides valuable information for desiccation operations and for determining when treatment goals have been reached. This type of information can be obtained through use of geophysical methods. Neutron moisture logging, cross-hole electrical resistivity tomography, and cross-hole ground penetrating radar approaches were evaluated with respect to their ability to provide effective spatial and temporal monitoring of desiccation during a treatability study conducted in the vadose zone of the DOE Hanford Site in WA.

  19. Volumetric Geophysical Retrievals in Precipitating Cloud Systems

    NASA Astrophysics Data System (ADS)

    Collis, S. M.; North, K. W.; Jensen, M. P.; Kollias, P.; Williams, C. R.; Bharadwaj, N.; Fridlind, A. M.; Widener, K.; Giangrande, S.

    2011-12-01

    Cloud and climate modeling efforts focused around the Mid-Latitude Continental Convective Clouds Experiment (MC3E) require the retrieval of high quality geophysical parameters pertinent to storm microphysical and dynamical properties. The installation of high resolution polarimetric X- and C-Band scanning radars have greatly enhanced measurements at the Atmospheric Radiation Measurement Southern Great Plain site, however, the volumetric data collected by these sensors is only indirectly related to storm properties. This presentation will outline efforts towards creating a suite of model-like Value Added Products (VAPs) for MC3E derived using existing and new retrieval techniques. Particular focus will be on retrieval of storm dynamics, precipitation microphysics and rainfall accumulations from the scanning radar measurements. Algorithm details and verification efforts will be showcased as well as a timetable for data availability.

  20. The geology and geophysics of Mars

    NASA Technical Reports Server (NTRS)

    Saunders, R. S.

    1976-01-01

    The current state of knowledge concerning the regional geology and geophysics of Mars is summarized. Telescopic observations of the planet are reviewed, pre-Mariner models of its interior are discussed, and progress achieved with the Mariner flybys, especially that of Mariner 9, is noted. A map of the Martian geological provinces is presented to provide a summary of the surface geology and morphology. The contrast between the northern and southern hemispheres is pointed out, and the characteristic features of the surface are described in detail. The global topography of the planet is examined along with its gravitational field, gravity anomalies, and moment of inertia. The general sequence of events in Martian geological history is briefly outlined.

  1. 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.

  2. 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.

  3. Geophysical Effects of the Earth's Monthly Motion

    NASA Astrophysics Data System (ADS)

    Sidorenkov, N. S.; Zhigailo, T. S.

    The generation of a lunar tidal force is a major geophysical effect of the Earth's monthly motion.It is shown that synoptic processes vary simultaneously with tidal oscillations of the Earth's rotation rate and weather exhibits changes near their extremes, i.e., when the Earth is in certain positions on its monthly orbit.It is found that the quasi-biennial oscillation of the wind direction in the equatorial stratosphere is a combined oscillation caused by three periodic processes experienced by the atmosphere: (a) lunisolar tides, (b) the precession of the orbit of the Earth's monthly rotation around the barycenter of the Earth-Moon system, and (c) the motion of the perigee of this orbit.Interference of the 1.20-year Chandler wobble with sidereal, anomalistic, and synodic lunar oscillations gives rise to beats, i.e., to slow periodic variations in the wobble amplitude with periods of 32 to 51 years.

  4. Geophysics could explain Ancient Maya Myth

    NASA Astrophysics Data System (ADS)

    Bruchez, Margaret Sabom

    According to Maya mythology, the splendor of the principal entity, the Feathered Serpent, is exalted at Lake Atitlán in southwestern Guatemala. A chance look at a phenomenon in the natural environment reveals the possible geophysical basis of this myth.More than poetic fancy, the flight of the Feathered Serpent could refer to the dissipation of a soliton wave formed in the 130-km2 caldera lake. In the myth, recounted in the sixteenth century document los anales de los caqchiqueles, the newly acceded leader of the Kaqchikel-speaking Maya tribe rises from the lake transformed as the Feathered Serpent [Recinos and Goetz, 1953, p. 76]. Residents claim a gigantic serpent, Xocomil, still lives in the waters.

  5. Geophysics Could Explain Ancient Maya Myth

    NASA Astrophysics Data System (ADS)

    Sabom Bruchez, Margaret

    2005-03-01

    According to Maya mythology, the splendor of the principal entity, the Feathered Serpent, is exalted at Lake Atitlán in southwestern Guatemala. A chance look at a phenomenon in the natural environment reveals the possible geophysical basis of this myth. More than poetic fancy, the flight of the Feathered Serpent could refer to the dissipation of a soliton wave formed in the 130-km2 caldera lake. In the myth, recounted in the sixteenth century document los anales de los caqchiqueles, the newly acceded leader of the Kaqchikel-speaking Maya tribe rises from the lake transformed as the Feathered Serpent [Recinos and Goetz, 1953, p. 76]. Residents claim a gigantic serpent, Xocomil, still lives in the waters.

  6. Symmetries in geology and geophysics

    PubMed Central

    Turcotte, Donald L.; Newman, William I.

    1996-01-01

    Symmetries have played an important role in a variety of problems in geology and geophysics. A large fraction of studies in mineralogy are devoted to the symmetry properties of crystals. In this paper, however, the emphasis will be on scale-invariant (fractal) symmetries. The earth’s topography is an example of both statistically self-similar and self-affine fractals. Landforms are also associated with drainage networks, which are statistical fractal trees. A universal feature of drainage networks and other growth networks is side branching. Deterministic space-filling networks with side-branching symmetries are illustrated. It is shown that naturally occurring drainage networks have symmetries similar to diffusion-limited aggregation clusters. PMID:11607719

  7. Resources for History of Geophysics at AIP

    NASA Astrophysics Data System (ADS)

    Good, G. A.

    2012-12-01

    The history programs of the American Institute of Physics -- the Center for History of Physics and the Niels Bohr Library & Archives -- maintain a wide variety of research resources for the history of physics generally, and for the history of geophysics in particular. AIP has over 20,000 photographs online, nearly 1000 oral history interview transcripts, and much more. The International Catalog of Sources provides an online union catalog of manuscript collections held worldwide. An important collection of IUGG records is available onsite, as also is the recently accessioned collection of AGU papers. As the 2019 centenary of AGU approaches, these resources will be of interest to both AGU members and historians of science.;

  8. Opening doors for geophysics in soil sciences

    NASA Astrophysics Data System (ADS)

    Müller, Martin

    Urban soils are subject to strong variations in environmental conditions such as water flow, solute transport, and heat budget. For soil scientists, the effects of the temporal and spatial dynamics of soil moisture distribution on the sorption and release of contaminants is crucial for understanding soil processes.The INTERURBAN research project was formed in 2001 in Berlin, Germany, to study the dynamics of water and materials at urban locations while giving special consideration to spatial heterogeneity organic soil substance, and soil-biological transformation processes. The project is the cooperative effort of six departments of the Technical University of Berlin and the Free University of Berlin; namely, the departments of soil sciences, water quality control, environmental chemistry microbiology soil zoology, and applied geophysics.

  9. 1994 Geophysical images contest entries sought

    NASA Astrophysics Data System (ADS)

    As part of AGU's 75th Anniversary year, entries are sought for the 1994 Geophysical Images Contest. Over ninety photographs, computer graphics, posters, maps, slides, and videos were submitted in 1993. The winning images were displayed at the AGU Spring Meeting in Baltimore, and again at the Fall Meeting in San Francisco, along with the other images submitted.First place winner in the computer graphics section was “Western Mediterranean Sea Salinity Field,” submitted by Jacques Haus. Honorable Mentions went to Wei-jia Su for “A View of Whole Mantle Heterogeneity” and Toshiro Tanimoto, Paul Morin, David Yuen, and Yu-Shen Zhang for “Visualization of the Earth's Upper Mantle.”

  10. A Network of Geophysical Observatories for Mars

    NASA Technical Reports Server (NTRS)

    Banerdt, W. Bruce; Christensen, Ulrich; Crisp, David; Dehant, Veronique; Delory, Greg; Lognonne, Philippe; Sotin, Christophe; Spohn, Tilman

    2005-01-01

    For the past 30 years there has been a strong consensus within the international scientific community in favor of sending a network of geophysical landers to Mars to characterize the near-surface weather and climate, determine the large-scale atmospheric dynamics and explore the interior structure and composition. Despite this scientific support, there has been an unbroken string of proposed missions over the past fifteen years which have failed for programmatic reasons to progress beyond the design stage (Mars Network Mission, MESUR, Marsnet, InterMarsnet, NetLander). In this presentation, we review the scientific rationale and technical requirements for such a mission, and discuss current activities aimed toward its implementation.

  11. Analysis of geophysical measurements and spacecraft interactions

    NASA Astrophysics Data System (ADS)

    Bass, J. N.; Bhavnani, K. H.; Bonito, N. A.; Bounar, K. H.; Grady, P. L.

    1993-01-01

    Investigations were supported to analyze geophysical measurements with integrated applications of ephemerides physics and mathematics of the ionosphere and near space. The projects undertaken included analytical and computational simulation of the interactive spacecraft processes associated with the following: charging, contamination, liquid venting, and critical ionization velocity; data based and analytical investigations of trapped particles, dosage, magnetic fields, and instrumentation for the CRRES experiment; and data based studies of auroral electron and ion precipitation including neural network techniques, ionospheric scintillation and OTH backscatter, and atmospheric density and orbital decay. Systems were developed and applied for calibration and processing of the CRRES and APEX magnetometers, and for generation of satellite attitude and ephemeris. Techniques employed for applying coordinate systems, depicting vehicle and astronomical circumstances, and interactively presenting data in conventional and color formats are also described.

  12. 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.

  13. Terrestrial hydrological Research and Geophysics: Quo Vadis?

    NASA Astrophysics Data System (ADS)

    Vereecken, H.; Huisman, J. A.; van der Kruk, J.; Bogena, H.; Pohlmeier, A.; Koestel, J.; Lambot, S.; Vanderborght, J.

    2009-04-01

    Geophysical methods may play an important role in managing our terrestrial environment and in maintaining ecosystem functioning and services. Especially, the application and further development of hydrogeophysical methods seem very promising to maintain and protect soil and groundwater quality. Hydrogeophysical methods may help to improve our control on storage, filter and buffer functions of soils and groundwater systems. Moreover, methods are needed that will help us to bridge the gap between the scale of measurements and observations and the scale at which management of terrestrial systems takes place. In this presentation several examples will be presented showing how hydrogeophysical research can contribute in meeting these challenges. Recent progress in the field of magnetic resonance imaging, electrical resistivity tomography and spectral induced polarisation to investigate flow and transport processes in soils will be presented. In the field of high frequency hydrogeophysics, advanced full-waveform forward and inverse modelling procedures have been developed for ground penetrating radar technology, which are now routinely used for high-resolution, real-time mapping of surface soil moisture at the field scale. Integrated inversion and data fusion strategies, where both geophysical and hydrological models are coupled, further extend information retrieval capabilities also in real-time, and permits advanced interpretation of time-lapse data for hydrological process identification, water dynamics monitoring and soil hydraulic properties determination. Advances in wireless and sensor technologies are increasing the feasibility of using distributed sensor networks for observing soil water and hydrological processes at the intermediate scale, bridging the gap between ground-based sensors and remote sensing platforms.

  14. Solid-Earth Geophysics in Latinamerica

    NASA Astrophysics Data System (ADS)

    Urrutia-F, J.

    2003-12-01

    Geophysical research increasingly requires of multidisciplinary global approaches. This is particularly the case on Earth system science, where studies of our planet attempt to integrate phenomena from the inner core to surface, hydrosphere, atmosphere, and beyond the magnetosphere into our solar system. To accomplish this, studies span wide ranges of spatial and temporal scales. Increasing understanding of how deeply interrelated are the Earth components and processes, the potential global impact of human activities, and view of our planet as a spaceship journeying in the solar system and galaxy emphasize the need of international cooperation. New tools are being developed to investigate the planet at different scales, with high spatial-temporal resolution, and we say - Earth scientists (particularly from highly-developed countries) do conduct global research. In this context, what is the situation in developing countries? Do all studies in foreign countries classify as international research? - Foreign countries to some of us are the home and study areas for other researchers. What are the conditions, facilities, projects and views of those other researchers? We attempt to examine some of these questions from an inside analysis and some examples in solid Earth geophysics from a Latinamerican country. How is the situation, size of research community, education and training, facilities, economic support, major problems, participation in international programs, and bilateral and multinational collaboration? What are the perspectives for future development within the region and in an international context? International research collaboration has an immense potential and is clearly needed for study of our planet. Understanding it in terms of unselfish cooperation in equal terms with fellow researchers is yet a major challenge to make the most of that potential.

  15. Research e-infrastructure for "Geophysics" mission.

    NASA Astrophysics Data System (ADS)

    Nazarov, V.; Mogilevsky, M.; Nazirov, R.; Eismont, N.; Melnik, A.

    2009-04-01

    Space mission "Geophysics" intended for monitoring of ionospheric plasma parameters, electromagnetic emission and solar activity. In the frame of the project will be launched five small satellites on solar-synchronous orbits: two satellites on circular orbit, altitude ~700 km, orbit plane - morning-evening, another two satellites at the same altitude but orbit plane - day-night and the last satellite - on elliptic orbit with ~1200 km apogee and ~400 km perigee. Such choice of spacecraft constellation configuration is so some extent similar to the configuration usually used for the Earth remote sensing tasks. It gives advantages for the project because it allows to apply technologies of remote sensing satellites practically off shelved. From the other side it gives new possibilities for geophysics experiments followed from the fact that the measurements may be considered as the ones done by the instruments having the size of the Earth scale. However it brings more strict requirements for information support of the mission in general and for ground segment particularly. In needs not only on-line processing but on-line interpretation too, operative feedback link between interpretation and operation subsystems etc. Satisfaction of such strict requirements from one side and necessity for using of existing ground resources (taking in account budget limitations) implied creating of unified ground information infrastructure for target payload of the mission. This e-infrastructure will cover traditional ground systems which are treated as systems based on Resource-Oriented Architecture (ROA) and will produce unified integration platform based on Service-Oriented Architecture (SOA) which will collects all needed services and provides access to them in frame of unified cyber-infrastructure. The article describes technology and methodology aspects of design of this system.

  16. When tsunamology and geophysics clash, throw geophysics in the trash (Sergey Soloviev Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Synolakis, Costas

    2014-05-01

    Tsunami science has evolved differently from research on other extreme natural hazards, primarily because of the unavailability, until recently, of instrumental recordings of tsunamis in the open ocean. Recordings and observations have catapulted tsunamology into a rapidly evolving high-interdisciplinary field spanning geology, geophysics, oceanography, coastal engineering, hydrodynamics and social science. I will discuss progress in tsunami geology and geophysics in the past thirty years, and describe the evolution of numerical codes and analytical results. I will describe field observations which, while counter-intuitive at first, they later helped explain complex dynamics and assisted us in improving tsunami hazard mitigation. While the grand science synthesis remains elusive, we are converging to where we can reduce tsunami-related fatalities and injuries by about one half in the next few years.

  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. Laboratory Building

    SciTech Connect

    Herrera, Joshua M.

    2015-03-01

    This report is an analysis of the means of egress and life safety requirements for the laboratory building. The building is located at Sandia National Laboratories (SNL) in Albuquerque, NM. The report includes a prescriptive-based analysis as well as a performance-based analysis. Following the analysis are appendices which contain maps of the laboratory building used throughout the analysis. The top of all the maps is assumed to be north.

  19. Near-surface geophysical investigations inside the cloister of an historical palace in Lecce, Italy

    NASA Astrophysics Data System (ADS)

    Nuzzo, L.; Quarta, T.

    2009-04-01

    Near-surface geophysics can play a major role in the framework of the Cultural Heritages diagnostics as the recourse to non-invasive geophysical methods is usually the only way to gain information on subsurface properties that can affect the stability of historical structures and accelerate degradation processes. In most cases the deterioration of ancient buildings is due to various causes: external, such as pollution, biological degradation and adverse climatic or microclimatic conditions; internal, such as a particular geological or hydro-geological setting or a combination of both. Therefore, being able to discriminate between the different sources and to identify the main process of decay becomes essential for the development of effective remediation actions. The present case study shows the main results of an integrated geophysical campaign performed inside the cloister of an important palace in Lecce, Southern Italy, in order to investigate the possible subsurface causes of deterioration affecting its pillars and walls and, more importantly, some altars of the annexed church. The historical building, named Palazzo dei Celestini, was formerly a monastery directly connected to the Basilica of Santa Croce and nowadays is the head office of the Province of Lecce Administration and the Prefecture. With its rich baroque façade, Palazzo dei Celestini and Santa Croce is the most famous architectural complex of the historical centre of Lecce. Its foundations generally rest on a very shallow and sometimes outcropping wet calcarenitic basement, evidenced by previous geophysical surveys performed in the nearby. The high capillarity of the local fine-grained calcarenitic stone used as building and ornamental material for the historical complex was thought to be responsible for the deterioration problems evidenced at some altars of the church and in the lower portion of the walls and pillars of the palace, although a previous microclimatic study inside the Basilica had

  20. 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

  1. The QuakeSim Project: Web Services for Managing Geophysical Data and Applications

    NASA Astrophysics Data System (ADS)

    Pierce, Marlon E.; Fox, Geoffrey C.; Aktas, Mehmet S.; Aydin, Galip; Gadgil, Harshawardhan; Qi, Zhigang; Sayar, Ahmet

    2008-04-01

    We describe our distributed systems research efforts to build the “cyberinfrastructure” components that constitute a geophysical Grid, or more accurately, a Grid of Grids. Service-oriented computing principles are used to build a distributed infrastructure of Web accessible components for accessing data and scientific applications. Our data services fall into two major categories: Archival, database-backed services based around Geographical Information System (GIS) standards from the Open Geospatial Consortium, and streaming services that can be used to filter and route real-time data sources such as Global Positioning System data streams. Execution support services include application execution management services and services for transferring remote files. These data and execution service families are bound together through metadata information and workflow services for service orchestration. Users may access the system through the QuakeSim scientific Web portal, which is built using a portlet component approach.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  3. 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

  4. Application of Geophysical Techniques in Glaciology

    NASA Astrophysics Data System (ADS)

    Murray, T.

    2006-05-01

    Glaciologists are faced with the problem that most processes that control ice motion or the transport of water and sediment occur either deep within the glacier ice or at the interface between it and the underlying substrate. However, glaciers are an ideal environment for the application of many geophysical techniques and they have led to significant advances in our understanding of glaciers and ice sheets. Surface and airborne radar has a long pedigree in glaciology and has been used extensively to map beds of the major ice sheets and isochrones within the ice. Cold ice, such as that in Antarctica is easy for radar energy to penetrate, but the water in warm ice scatters radar energy. For this reason it has proved more difficult to image the beds of outlet glaciers in Greenland. Recent advances, particularly in ground-penetrating radar, have meant that it has been possible to image sediment structures within the ice and to use the reflectivity at the bed capture some aspects of the basal water system. Radar energy does not normally penetrate into the beds of ice masses - which are often wet sediments. However, reflection seismics allows us to image further into the basal environment. Using the impedance contrast across the basal interface it is possible to determine whether basal sediments are frozen or unfrozen, and whether they are actively deforming or the ice is sliding over the bed. These questions are key in understanding the dynamics of an ice mass. As a glacier moves overs its bed, seismic energy can be released that provides information on the nature of the basal environment. These events record different source types and relative friction between regions of the bed (so-called "sticky" and "slippery" spots). Considerable work is required to fully exploit the potential of this technique which requires integration with GPS measurements, locating events, and modeling of source types. Geophysical techniques are an ideal tool for exploring the inaccessible

  5. 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

  6. Environmental geophysics at J-Field, Aberdeen Proving Ground, Maryland

    SciTech Connect

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

    1994-11-01

    Geophysical data collected at J-Field, Aberdeen Proving Ground, Maryland, were used in the characterization of the natural hydrogeologic framework of the J-Field area and in the identification of buried disturbances (trenches and other evidences of contamination). Seismic refraction and reflection data and electrical resistivity data have aided in the characterization of the leaky confining unit at the base of the surficial aquifer (designated Unit B of the Tertiary Talbot Formation). Excellent reflectors have been observed for both upper and lower surfaces of Unit B that correspond to stratigraphic units observed in boreholes and on gamma logs. Elevation maps of both surfaces and an isopach map of Unit B, created from reflection data at the toxic burning pits site, show a thickening of Unit B to the east. Abnormally low seismic compressional-wave velocities suggest that Unit B consists of gassy sediments whose gases are not being flushed by upward or downward moving groundwater. The presence of gases suggests that Unit B serves as an efficient aquitard that should not be penetrated by drilling or other activities. Electromagnetic, total-intensity magnetic, and ground-penetrating radar surveys have aided in delineating the limits of two buried trenches, the VX burning pit and the liquid smoke disposal pit, both located at the toxic burning pits site. The techniques have also aided in determining the extent of several other disturbed areas where soils and materials were pushed out of disposal pits during trenching activities. Surveys conducted from the Prototype Building west to the Gunpowder River did not reveal any buried trenches.

  7. A Geophysical Study of Fissures in Pahrump, Nevada

    NASA Astrophysics Data System (ADS)

    Hirsch, A. C.; McEwan, M. J.; Howley, R. A.; Mehling, J. B.; Snelson, C. M.; Drohan, P.

    2004-12-01

    Earth fissures are surface expressions of deep fracturing subsidence systems caused by groundwater withdrawl greater than aquifer recharge. This type of subsidence is most common in arid environments of the south western U.S. such as, Las Vegas, NV, Phoenix, AZ, and areas in New Mexico. In addition, fissures have recently been identified in the Pahrump Valley in southwestern Nevada just west of Las Vegas. The city of Pahrump has experienced an increase in population and economic growth. This growth has lead to a higher demand in the use of the areas natural resources. One major concern is groundwater pumping and over-watering of the land surface. Pahrump has experienced significant differential subsidence within the valley causing significant structural damage to infrastructure. This differential subsidence is most readily identified by its surface expression as fissures. Earth fissures are not only shallow surface features but can be 10's of meters deep and 100's of meters long. These ground failures can be exacerbated by faults at depth, shallow bedrock, and/or differential compaction. However, the most significant cause is from groundwater withdrawl. Several geophysical methods were performed on the fissures to better understand their subsurface expression, trend, and ultimately their affect on the city of Pahrump. Seismic refraction, reflection, ground penetrating radar (GPR), and gravity measurements were performed on the fissures and surrounding area including local faults. Our initial studies show the fissures propagating for long distances, in a variety of shapes, and trending in a north-south direction. Initial GPR studies show high fissure reflections at approximately 1 and 1.5 meters along with general slumping features below these reflections. Fissures are an unmitigatable problem. Our results will help identify fissures in the area that do not have a surface expression as well as mapping the current fissures and their extent. These results can be used

  8. Building Skills to Build Communities

    ERIC Educational Resources Information Center

    Russell, Geoff

    2011-01-01

    Communities are at the heart of the government's vision for the Big Society. And it's the author's strongly held view that skills should be at the heart of each and every one of those communities. If one grows the skills of an individual then the community will flourish. There is a job to be done in building skills to build communities--skilled…

  9. 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.

  10. Contemporary geophysics from Babylonian clay tablets

    NASA Astrophysics Data System (ADS)

    Morrison, L. V.; Stephenson, F. R.

    1997-01-01

    History and astronomy can be brought to bear on problems in contemporary geophysics. From seemingly crude ancient and medieval observations of eclipses, we show that variations in the length of the day can be traced back over the past 2500 years. The tidal torque exerted by the Moon (and, to a lesser extent, by the Sun) is the dominant mechanism in reducing the Earth's spin. It is known that by this mechanism, the length of the day is increasing by .- 1 + 2 3ms per century (mscy ). By analysing observations of eclipses, we find the actual measured change in the length of the day to be + 1.7mscy , from which we conclude that besides the tidal contribution, there is another long-term component acting to reduce - 1 the length of the day by- 0.6mscy . This component, which is thought to result from the decrease in the Earth's oblateness following the last Ice Age, is consistent with recent measurements made by artificial satellites. - 1

  11. Magnetotellurics as a multiscale geophysical exploration method

    NASA Astrophysics Data System (ADS)

    Carbonari, Rolando; D'Auria, Luca; Di Maio, Rosa; Petrillo, Zaccaria

    2016-04-01

    Magnetotellurics (MT) is a geophysical method based on the use of natural electromagnetic signals to define subsurface electrical resistivity structure through electromagnetic induction. MT waves are generated in the Earth's atmosphere and magnetosphere by a range of physical processes, such as magnetic storms, micropulsations, lightning activity. Since the underground MT wave propagation is of diffusive type, the longer is the wavelength (i.e. the lower the wave frequency) the deeper will be the propagation depth. Considering the frequency band commonly used in MT prospecting (10-4 Hz to 104 Hz), the investigation depth ranges from few hundred meters to hundreds of kilometers. This means that magnetotellurics is inherently a multiscale method and, thus, appropriate for applications at different scale ranging from aquifer system characterization to petroleum and geothermal research. In this perspective, the application of the Wavelet transform to the MT data analysis could represent an excellent tool to emphasize characteristics of the MT signal at different scales. In this note, the potentiality of such an approach is studied. In particular, we show that the use of a Discrete Wavelet (DW) decomposition of measured MT time-series data allows to retrieve robust information about the subsoil resistivity over a wide range of spatial (depth) scales, spanning up to 5 orders of magnitude. Furthermore, the application of DWs to MT data analysis has proven to be a flexible tool for advanced data processing (e.g. non-linear filtering, denoising and clustering).

  12. Geophysical phenomena classification by artificial neural networks

    NASA Technical Reports Server (NTRS)

    Gough, M. P.; Bruckner, J. R.

    1995-01-01

    Space science information systems involve accessing vast data bases. There is a need for an automatic process by which properties of the whole data set can be assimilated and presented to the user. Where data are in the form of spectrograms, phenomena can be detected by pattern recognition techniques. Presented are the first results obtained by applying unsupervised Artificial Neural Networks (ANN's) to the classification of magnetospheric wave spectra. The networks used here were a simple unsupervised Hamming network run on a PC and a more sophisticated CALM network run on a Sparc workstation. The ANN's were compared in their geophysical data recognition performance. CALM networks offer such qualities as fast learning, superiority in generalizing, the ability to continuously adapt to changes in the pattern set, and the possibility to modularize the network to allow the inter-relation between phenomena and data sets. This work is the first step toward an information system interface being developed at Sussex, the Whole Information System Expert (WISE). Phenomena in the data are automatically identified and provided to the user in the form of a data occurrence morphology, the Whole Information System Data Occurrence Morphology (WISDOM), along with relationships to other parameters and phenomena.

  13. Understanding biogeobatteries: Where geophysics meets microbiology

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

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

  14. 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

  15. Geophysical constraints on Washington convergent margin structure

    USGS Publications Warehouse

    Finn, C.

    1990-01-01

    Gravity and magnetic maps of western Washington reveal the lateral structure and fabric of the Washington Coast Range, Puget Basin, and southern Washington Cascade Range. Two-dimensional gravity and magnetic modeling constrained with geological and other geophysical data indicate that the Coast Range Province rocks are about 1 km thick at the coast, thickening to as much as 30 km near their postulated eastern edge. A composition largely of basalt and gabbro with little interbedded sediments is suggested. Under these rocks may be mantle or a subduction complex composed of dense mafic, ultramafic, and sedimentary rocks like that proposed to underlie Vancouver Island. The Washington model requires that the proposed subduction complex be more dense than the trench sediments and, therefore, that material denser than sediments be incorporated within it. The absence of continental mantle and the modeled wedge shape of the Coast Range Province upper crust suggest that erosion of the bottom of the overriding plate by subduction processes may have occurred. -from Author

  16. Understanding biogeobatteries: Where geophysics meets microbiology

    SciTech Connect

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

    2009-08-15

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

  17. 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.

  18. 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

  19. 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

  20. Near-surface geophysical investigations inside the cloister of the historical palace 'Palazzo dei Celestini' in Lecce, Italy

    NASA Astrophysics Data System (ADS)

    Nuzzo, Luigia; Quarta, Tatiana

    2010-06-01

    Non-invasive geophysical investigations are usually the only way to gain information on subsurface properties that can affect the stability of historical structures and accelerate degradation processes. A combined multi-frequency ground-penetrating radar (GPR) geoelectrical and induced polarization (IP) survey was performed in the cloister of 'Palazzo dei Celestini', Lecce, southern Italy, in order to investigate possible subsurface causes of deterioration. The historical palace was originally a convent connected to the Basilica of 'Santa Croce' and is now the head office of the Province of Lecce Administration and the Prefecture. Built in Pietra Leccese, a fine-grained calcarenite, Santa Croce and Palazzo dei Celestini is the most famous baroque architectural complex of the historical centre of Lecce. The high capillarity of the building material causes deterioration problems especially at some altars of the church and in the lower portion of the walls and pillars of the monumental building. The integrated geophysical survey yielded a detailed description of the shallow stratigraphical and hydro-geological setting of the area and an accurate location of ancient and modern drainage systems. The geophysical information was essential for identifying natural or anthropogenic causes of the local increase in subsoil moisture that could accelerate the degradation process and for developing effective remediation activities.

  1. Building Languages

    MedlinePlus

    ... Communication programs use some form of Simultaneous Communication (speaking and signing at the same time). This program includes building blocks such as Conceptually Accurate Signed English (CASE), Finger Spelling, Listening, Manually Coded English (MCE), ...

  2. 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.

  3. Astronaut-Deployable Geophysical and Environmental Monitoring Stations

    NASA Astrophysics Data System (ADS)

    Guzewich, S. D.; Bleacher, J. E.; Smith, M. D.; Khayat, A.; Conrad, P.

    2017-02-01

    Geophysical and environmental monitoring stations could be deployed by astronauts exploring Mars, the Moon, or asteroids, and create a broad network that would collect high-value scientific information while also enhancing astronaut safety.

  4. Enabling Technologies for a Future Lunar and Planetary Geophysical Network

    NASA Astrophysics Data System (ADS)

    Neal, C. R.; Currie, D.; Grimm, R.; Kedar, S.; Nagihara, S.; Siegler, M.; Weber, R.; Zacny, K.

    2017-02-01

    A long-lived, multi-station, global lunar geophysical network will yield information about primary terrestrial differentiation, as well as potential hazards to long term human surface exploration. The technology can be applied to other planets.

  5. The clouded crystal ball: Comments on geophysical prediction

    NASA Technical Reports Server (NTRS)

    Silverman, S. M.

    1979-01-01

    The concepts of prediction in the geophysical domain are considered with emphasis on the areas of difficulties and the nature of these difficulties. Differences in defining and determining the validity and significance of hypotheses and observational correlations are covered.

  6. Reports of Planetary Geology and Geophysics Program, 1990

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Abstracts of reports from NASA's Planetary Geology and Geophysics Program are presented. Research is documented in summary form of the work conducted. Each report reflects significant accomplishments within the area of the author's funded grant or contract.

  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. Geophysical Mapping and Monitoring of Active Planets (GMAP)

    NASA Astrophysics Data System (ADS)

    McGovern, P. J.; Goossens, S. J.; Lemoine, F. G.

    2017-02-01

    Recent findings require a strongly upward revision of volcano-tectonic activity rate estimates for Venus and Mars. We propose a program of Geophysical Mapping and Monitoring of Active Planets (GMAP) including seismology, gravimetry, InSAR, and GPS.

  9. Innovations In Site Characterization: Geophysical Investigation at Hazardous Waste Sites

    EPA Pesticide Factsheets

    This compendium describes a number of geophysical technologies and methods that were used at 11 sites with significantly different geological settings and types of subsurface contamination, ranging from relatively homogeneous stratigraphy to the highly ...

  10. Reports of planetary geology and geophysics program, 1989

    NASA Technical Reports Server (NTRS)

    Holt, Henry (Editor)

    1990-01-01

    Abstracts of reports from Principal Investigators of NASA's Planetary Geology and Geophysics Program are compiled. The research conducted under this program during 1989 is summarized. Each report includes significant accomplishments in the area of the author's funded grant or contract.

  11. The geology and geophysics of the Oslo rift

    NASA Technical Reports Server (NTRS)

    Ruder, M. E.

    1981-01-01

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

  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. Influence of geophysical factors on oblique-sounder ionospheric characteristics

    SciTech Connect

    Baranets, A.N.; Blagoveshchenskaya, N.F.; Borisova, T.D.; Bubnov, V.A.

    1988-10-01

    The purpose of this paper is to study the influence of geophysical factors, including magnetoionospheric disturbances, on decameter wave propagation over extended paths using oblique sounding (OS) data, and also to compare experimental and calculated OS ionograms for various conditions of radio waver propagation (season, time of day). Variations of oblique-sounder ionospheric characteristics along a 9000 km long subauroral path for various geophysical conditions are considered. A comparison is made of experimental and calculated ionograms of oblique sounding.

  14. 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.

  15. Geophysical constraints on Washington convergent margin structure

    SciTech Connect

    Finn, C. )

    1990-11-10

    Gravity and magnetic maps of western Washington reveal the lateral structure and fabric of the Washington Coast Range, Puget Basin, and southern Washington Cascade Range. The magnetic and gravity maps show large amplitude positive anomalies associated with the shallow but largely buried section of Washington Coast Range mafic rocks which are separated by negative anomalies over deep sedimentary basins. The positive anomalies indicate that the Coast Range mafic basement extends farther east than previously thought, at least as far east as the longitude of Seattle. Linear and steep gravity and magnetic gradients indicate many unmapped, often buried faults in the Washington Coast Range Province. Magnetic highs are also associated with mapped batholiths in the Cascade arc. Two-dimensional gravity and magnetic modeling constrained with geological and other geophysical data indicate that the Coast Range Province rocks are about 1 km thick at the coast, thickening to as much as 30 km near their postulated eastern edge. A maximum boundary on the average density of the upper 15-20 km of the rocks that compose the Coast Range Province of 2,920 kg/m{sup 3} was established by the modeling, suggesting a composition largely of basalt and gabbro with little interbedded sediments. The author's Washington model requires that the proposed subduction complex be more dense than the trench sediments and, therefore, that material denser than sediments be incorporated within it. The absence of continental mantle and the modeled wedge shape of the Coast Range Province upper crust suggest that erosion of the bottom of the overriding plate by subduction processes may have occurred.

  16. Advances in borehole geophysics for hydrology

    SciTech Connect

    Nelson, P.H.

    1982-01-01

    Borehole geophysical methods provide vital subsurface information on rock properties, fluid movement, and the condition of engineered borehole structures. Within the first category, salient advances include the continuing improvement of the borehole televiewer, refinement of the electrical conductivity dipmeter for fracture characterization, and the development of a gigahertz-frequency electromagnetic propagation tool for water saturation measurements. The exploration of the rock mass between boreholes remains a challenging problem with high potential; promising methods are now incorporating high-density spatial sampling and sophisticated data processing. Flow-rate measurement methods appear adequate for all but low-flow situations. At low rates the tagging method seems the most attractive. The current exploitation of neutron-activation techniques for tagging means that the wellbore fluid itself is tagged, thereby eliminating the mixing of an alien fluid into the wellbore. Another method uses the acoustic noise generated by flow through constrictions and in and behind casing to detect and locate flaws in the production system. With the advent of field-recorded digital data, the interpretation of logs from sedimentary sequences is now reaching a sophisticated level with the aid of computer processing and the application of statistical methods. Lagging behind are interpretive schemes for the low-porosity, fracture-controlled igneous and metamorphic rocks encountered in the geothermal reservoirs and in potential waste-storage sites. Progress is being made on the general problem of fracture detection by use of electrical and acoustical techniques, but the reliable definition of permeability continues to be an elusive goal.

  17. Our Buildings, Ourselves.

    ERIC Educational Resources Information Center

    Roodman, David Malin; Lenssen, Nicholas

    1994-01-01

    Reviews in detail environmental impacts associated with buildings. Discusses building construction, internal environments, building life spans, building materials, protection from climate, and amenities. (LZ)

  18. The Use of Near-Surface Geophysics in the Design of a Subsurface Water Management System

    NASA Astrophysics Data System (ADS)

    Fogwell, T. W.; Rymer, M.

    2008-12-01

    The buildings on a college campus have frequently been flooded at various times of the year. The existence of several springs on the campus, including at least one immediately adjacent to one of the buildings, suggested that a high water table was the cause of some of the problems. The groundwater enters the campus from the direction of the hills east of the campus. We carried out investigations of the hydrology of the campus in order to an engineer a solution to the water intrusion problem. In the process of evaluating the hydrology, we instigated a monitoring plan, installed the necessary wells for this plan, and carried out monitoring over both wet and dry seasons. The information from this monitoring has been combined with geophysical information derived from seismic surveys, core samples, and bore hole logging in order to achieve a complete picture of the hydrology of the campus. Geophysical logs have been produced for the same wells from which we took the core samples. This information has then been combined with seismic p-wave and s-wave velocity data derived from a total of four intersecting lines on the campus in order to produce a comprehensive understanding of both the hydrology and the governing geological features. The exact location of a fault running through the campus was determined, as well as any effect that it might have on the hydrology. In the effort to save the campus buildings from flooding, a method of diverting the groundwater has been proposed. Since the campus has expressed interest in keeping the project relatively eco-friendly, the design option presented has resulted in minimum energy costs and maximum resource conservation. The overall system design consists of interception and infiltration.

  19. 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

  20. To build capacity, build confidence

    NASA Astrophysics Data System (ADS)

    Hewitson, Bruce

    2015-07-01

    The history of attempts to spread scientific know-how beyond western centres of excellence is littered with failures. Capacity building needs long-term commitment, a critical mass of trainees, and a supportive home environment.

  1. 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

  2. Use of geophysical methods to map subsurface features at levee seepage locations

    NASA Astrophysics Data System (ADS)

    Brackett, Thomas C.

    The Great Flood of 2011 caused moderate to severe seepage and piping along the Mississippi River levees in Northwest Mississippi. The aim of this thesis was to implement geophysical techniques at two seepage locations in order to give a better understanding of the causes of underseepage and information on how to mitigate the problem. Sites near Rena Lara in Coahoma County and near Francis in Bolivar County were chosen to conduct this survey. Electrical Resistivity Tomography (ERT) and Electromagnetic Induction (EM) surveys were conducted on and adjacent to levees to identify seepage pathways and any dominant geological features at the sites. Results from geophysical surveys revealed that Francis and Rena Laura each had a prominent geomorphologic feature that was attributing to underseepage. Seepage at Francis was the result of a sand filled channel capped by a clay overburden. Permeable materials at the base of the channel served as a conduit for transporting river water beneath the levee. The seepage surfaced as sand boils where the overlying clay overburden was thin or non-existent. Investigations at the Rena Lara site revealed a large, clay-filled swale extending beneath the levee. The clay within the swale has relatively low horizontal permeability, and concentrated the seepage flow towards more permeable zones on the flanks of the swale. This resulted in the formation of sand boils at the base of the levee. Both geomorphic features at Francis and Rena Lara were identified as surface drainages using remote sensing data. With the assistance of borehole and elevation data, geophysics was successfully used to characterize the features at each site. Properties such as permeability and clay content were derived from responses in electrical conductivity and used to build seepage models at each site. These models will hopefully be considered when determining seepage conditions and mitigation techniques at other sites along the levee.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  4. 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

  5. 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

  6. The evolution of Reviews of Geophysics

    NASA Astrophysics Data System (ADS)

    Heirtzler, J. R.

    1988-11-01

    The Gulf Coast province provides an array of scientific dilemmas ranging from the origin of the gulf itself to the causes and effects of long-lasting circulation of hot, deep waters throughout the thick sedimentary section. The nature of the underlying crust and superjacent sediments and their contained waters; the precise timing of rifting; depositional history and diagenesis of the sedimentary sequence; fluid dynamics; geochemistry; hydrocarbon generation and migration; thermal history, including unusually high thermal gradient; and the fluid pressure regime in the deep sedimentary section are too poorly understood to permit quantitative analysis of processes that are of enormous scientific and practical importance. The area centered on DeWitt and Victoria counties, Texas, on the southeastern extension of the San Marcos arch, is probably the best location for a deep borehole to investigate these important phenomena and problems. The arch extends southeastward from exposed Grenville-age basement rocks of the Llano uplift and separates the deep South Texas and Houston embayment salt basins. Seaward of the Llano uplift, highly deformed and slightly metamorphosed rocks of the Ouachita-Marathon orogen have been intersected beneath Cretaceous sediments. The inferred edge of continental crust underlies an extensive Lower Cretaceous reef trend southeast of known Ouachita orogen rocks. Rapid thickening of Tertiary and possibly of Cretaceous sediments southeast of the shelf edge, together with geophysical indications of a relatively shallow Moho, suggests that "transitional continental crust" underlies sediments basinward of the inferred edge of continental crust. This transitional crust, the ultimate objective for a proposed deep well, could be rifted Grenville basement, buried rocks of the Ouachita trend, an island arc related to the Ouachita trend, or exotic continental basement related to a proto-South American continent. To achieve optimum results to guarantee

  7. Ceres' Geophysical Evolution Inferred from Dawn Data

    NASA Astrophysics Data System (ADS)

    Castillo-Rogez, Julie; Bowling, Timothy; Ermakov, Anton I.; Fu, Roger; Park, Ryan; Raymond, Carol; De Sanctis, Maria Cristina; Ammannito, Eleonora; Ruesch, Ottaviano; Prettyman, Thomas H.; Y McSween, Harry; Toplis, Michael J.; Russell, Christopher T.; Dawn Team

    2016-10-01

    If Ceres formed as an ice-rich body, as suggested by its low density and the detection of ammoniated phyllosilicates [1], then it should have differentiated an ice-dominated shell, analogous to large icy satellites [2]. Instead, Dawn observations revealed an enrichment of Ceres' shell in strong materials, either a rocky component and/or salts and gas hydrates [3, 4, 5, 6]. We have explored several scenarios for the emplacement of Ceres' surface. Endogenic processes cannot account for its overall homogeneity. Instead we suggest that Ceres differentiated an icy shell upon freezing of its early ocean that was removed as a consequence of frequent exposure by impacting after the dwarf planet migrated from a cold accretional environment to the warmer outer main belt (or when the solar nebula dissipated, if Ceres formed in situ). This scenario implies that Ceres' current surface represents the interface between the original ice shell and the top of the frozen ocean, a region that is extremely rich chemistry-wise, as illustrated by the mineralogical observations returned by Dawn [7]. Thermal modeling shows that the shell could remain warm over the long term and offer a setting for the generation of brines that may be responsible for the emplacement of Ahuna Mons [8] and Occator's bright spots [7] on an otherwise homogeneous surface [9]. An important implication is that Ceres' surface offers an analog for better understanding the deep interior and chemical evolution of large ice-rich bodies.References: [1] De Sanctis et al., Nature, 2015; [2] McCord and Sotin, Journal of Geophysical Research, 2005; [3] Park et al., Nature, 2016 (in press); [4] Hiesinger et al., Science (submitted); [5] Bland et al., Nature Geoscience, 2016 (in press); [6] Fu et al., AGU Fall Meeting, 2015 [7] De Sanctis et al., Nature, 2016 (in press); [8] Ruesch et al., Science, in revision; [9] Ammannito et al., Science, 2016 (accepted).Acknowledgements: Part of this work is being carried out at the Jet

  8. 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

  9. The Unconventional Revolution in Exploration Geophysics

    NASA Astrophysics Data System (ADS)

    House, N. J.

    2014-12-01

    how to develop them. MicroSeismic mapping has made completion more efficient and safe. While the geophysics involved in unconventional resource development may not be the first thought in the board room, thier data has become an accepted early development tool of successful oil and gas companies.

  10. Experiment Prevails Over Observation in Geophysical Science

    NASA Astrophysics Data System (ADS)

    Galvin, C.

    2006-05-01

    , but during that career, Popper painted himself into a philosophical corner by disallowing observation as contaminated with psychological problems and by advocating an aggressive deductive application of crucial experiments. As a result, in a 1974 review of what he really meant, Popper at least twice remembered ""Eddington's famous eclipse experiments of 1919."" The Web in 2006 lists NASA and NOAA acronyms for recent and ongoing research programs with geophysical content. A significant subset of these acronyms end in E or in EX, meaning experiment, but the scientific work done in the associated programs is actually observation. Experiment stands for actual Observation. This reversal in meaning recognizes the higher status of Experiment compared to Observation in the competition for government grants.

  11. Erosion of a model geophysical fluid

    NASA Astrophysics Data System (ADS)

    Luu, Li-Hua; Philippe, Pierre; Chambon, Guillaume

    2014-05-01

    A specificity of natural flows such as debris flows, landslides or snow avalanches is that, mostly, the material forming the static bed has mechanical properties similar to those of the flowing material (mud/mud, snow/snow). To explore the bed erosion phenomenon induced by such geophysical flows, we consider the geomaterial as a continuum by performing experiments in laboratory on a model fluid that can behaves as a solid or as a liquid, depending on the conditions. Indeed, we propose an experimental study where a yield-stress fluid is implemented to model both the eroding flow and the eroded bed. Our approach is to capture the process of erosion in terms of solid-liquid transition. The studied hydrodynamics consists of a pipe-flow disturbed by the presence of an obstacle. We use a polymer micro-gel Carbopol that exhibits a Hershel-Bulkley (HB) rheology. By taking advantage of the fluid transparency, the flow is monitoring by Particle Image Velocimetry (PIV) internal visualization technique. Upstream of the obstacle, a solid-liquid-like interface between a flow zone and a dead zone appears in the fluid. In this study, we aim to investigate the dominant physical mechanism underlying the formation of the static domain, by combining the rheological characterization of the yield-stress fluid (using a rheometer), with the observation of the morphological evolution of the system substratum / flow and the local measurement of related hydrodynamic parameters. Our first result shows that the flow above the dead zone behaves as a classical plug flow, whose velocity profile can successfully be described by a Hagen-Poiseuille equation including a HB rheology, but except in a thin zone (compared to the whole flow zone) at the close vicinity of the solid-liquid interface. Thanks to a high PIV measurement resolution, we then properly examine the typical feature lying at the tail of the velocity profile. The numerical derivation of the profile shows that the shear rate in this

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

  13. 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.

  14. 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.

  15. Geophysical investigations near the ancient Agora at the city of Argos, Greece

    NASA Astrophysics Data System (ADS)

    Zananiri, Irene; Hademenos, Vassilios; Piteros, Christos

    2010-06-01

    It is possible to reduce risk in archaeological excavations by identifying areas of high potential at an early stage and locating trenches accordingly. Towards this goal, a non-invasive geophysical survey was carried out at the city of Argos, which from the beginning of Archaic Times and through to Classical Times was one of the most prominent city-states. Based on historical and archaeological evidence, two sites were chosen near the ancient Agora of Argos. Total field and gradient magnetic measurements were collected over several grids, with 1 m spacing between measurement points. Representative samples were taken for laboratory measurements of the low-field magnetic susceptibility. Mapping, filtering and inversion procedures of the magnetic data have been used in tandem. The data management and cartographic representation was performed using Geographic Information Systems, where a geographic database was created, including all available information for the broader Argos area. The results of the geophysical survey were able to highlight the presence of linear and square structures possibly representing inhabitance ruins, namely small building remnants and road foundations according to observations from neighbouring excavations. Thus, the authors were able to suggest to the archaeologists excavation tests on the basis of the residual magnetic map.

  16. Building Trades.

    ERIC Educational Resources Information Center

    Gudzak, Raymond

    This curriculum guide provides materials for a competency-based course in building trades at the secondary level. The curriculum design uses the curriculum infused model for the teaching of basic skills as part of vocational education and demonstrates the relationship of vocationally related skills to communication, mathematics, and science…

  17. Team building

    SciTech Connect

    Kane, C.

    1993-04-01

    Power plants are particularly complicated projects with abundant opportunities for disputes. Efforts are beginning in the power industry to change the way the industry does business. Key elements of a comprehensive team-building approach include partnering, constructability, use of incentives, and the disputes review board.

  18. Building Sinusoids

    ERIC Educational Resources Information Center

    Landers, Mara G.

    2013-01-01

    In this article, the author describes the development and implementation of a measurement-based group activity designed to support students in understanding the connection between angle magnitude and the shape of the sine function. She explains that the benefit of this activity is that it allows students to build their trigonometric knowledge…

  19. 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

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

    NASA Astrophysics Data System (ADS)

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

    2007-05-01

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

  1. Geophysical Characterization and Monitoring for Anomalous Transport (Invited)

    NASA Astrophysics Data System (ADS)

    Day-Lewis, F. D.; Singha, K.

    2013-12-01

    For several decades, geophysical methods (e.g., electrical, electromagnetic, and radar) have been used to monitor transport of ionic tracers and contaminants, thus providing information about the spatial and temporal morphology and evolution of tracer or contaminant plumes. In the last five years, time-lapse geophysical methods have been applied to understand non-equilibrium between mobile and immobile (or less mobile) domains in porous media (e.g., fractures and matrix) and surface water (i.e., transient storage). Electrical methods have been used in combination with conventional sampling to investigate the exchange of solute between domains and thereby infer exchange rates and relative volumes of mobile and immobile domains. Other methods, including nuclear magnetic resonance and complex resistivity, have been used to study the distribution of pore sizes present, which in turn control anomalous transport. Here, we (1) review the underlying petrophysical/hydrologic link between anomalous transport and geophysical monitoring; (2) review the emerging body of work using geophysical methods to understand anomalous transport and summarize case studies involving field experiments at an aquifer-storage recovery site in Charleston, SC, and two Department of Energy sites in Hanford, WA and Naturita, CO; and (3) discuss potential future directions for geophysical research to further elucidate anomalous transport behavior.

  2. Exploring the geophysical signatures of microbial processes in the earth

    SciTech Connect

    Slater, L.; Atekwana, E.; Brantley, S.; Gorby, Y.; Hubbard, S. S.; Knight, R.; Morgan, D.; Revil, A.; Rossbach, S.; Yee, N.

    2009-05-15

    AGU Chapman Conference on Biogeophysics; Portland, Maine, 13-16 October 2008; Geophysical methods have the potential to detect and characterize microbial growth and activity in subsurface environments over different spatial and temporal scales. Recognition of this potential has resulted in the development of a new subdiscipline in geophysics called 'biogeophysics,' a rapidly evolving Earth science discipline that integrates environmental microbiology, geomicrobiology, biogeochemistry, and geophysics to investigate interactions that occur between the biosphere (microorganisms and their products) and the geosphere. Biogeophysics research performed over the past decade has confirmed the potential for geophysical techniques to detect microbes, microbial growth/biofilm formation, and microbe-mineral interactions. The unique characteristics of geophysical data sets (e.g., noninvasive data acquisition, spatially continuous properties retrieved) present opportunities to explore geomicrobial processes outside of the laboratory, at unique spatial scales unachievable with microbiological techniques, and possibly in remote environments such as the deep ocean. In response to this opportunity, AGU hosted a Chapman Conference with a mission to bring together geophysicists, biophysicists, geochemists, geomicrobiologists, and environmental microbiologists conducting multidisciplinary research with potential impact on biogeophysics in order to define the current state of the science, identify the critical questions facing the community, and generate a road map for establishing biogeophysics as a critical subdiscipline of Earth science research. For more information on the conference, see http://www.agu.org/meetings/chapman/2008/fcall/.

  3. Building No. 5, Main Building; Building NO. 9, Guard House ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Building No. 5, Main Building; Building NO. 9, Guard House (left). Viewed from across corner Lakeside Avenue and Main Street - Thomas A. Edison Laboratories, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  4. 2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. PRINTING AND ADVERTISING BUILDING, ADMINISTRATION BUILDING, MERCHANDISE BUILDING, AND GARDEN, VIEW TO SOUTHWEST - Sears Roebuck & Company Mail Order Plant, Bounded by Lexington & Grenshaw Streets, Kedzie Avenue & Independence Boulevard, Chicago, Cook County, IL

  5. Geophysical Constraints on Sediment Dispersal Systems

    NASA Astrophysics Data System (ADS)

    Johnstone, Elizabeth Anne Carruthers

    Geophysical and geological approaches were employed to understand sediment dispersal systems and their response to various forcing functions (i.e., sea level fluctuations, tectonic deformation, sediment supply, and climate change). Two end member marine environments were studied; one with high precipitation and sediment discharge (Gulf of Papua, Papua New Guinea) and the other with low precipitation and sediment discharge (Oceanside Littoral Cell). The high-sedimentation rate in the Gulf of Papua (GoP) yields high-fidelity records of Earth history. As part of the NSF Margins Source-to-Sink (S2S) program, we acquired CHIRP and core data across the GoP continental shelf that complemented onshore and offshore research in the region. CHIRP seismic data imaged three Holocene sedimentary lobes. The older Central lobe is downlapped by two younger lobes to the north and south. Sediment analysis showed that the older Central lobe has an elemental signature similar to the younger Northern lobe with both sourced from the Purari River watershed and lobe migration appears to be climatically controlled. The Southern lobe has elemental signatures more consistent with the Fly River watershed. Our results suggest the northern rivers began depositing sediments on the shelf during the Holocene sea level rise in the central region of the GoP and migrated abruptly north at ~2 kybp. Conversely, during the early Holocene transgression, sediments in the Fly drainage system were sequestered onshore infilling accommodation created in the large low-relief coastal plain during the sea level rise. Upon infilling the onshore accommodation, the Fly River delivered sediment to the ocean and formed the Southern lobe. Such differences in onshore storage capacity may introduce a lag between low-gradient rivers (Type I) with a large coastal plain versus high-gradient river systems (Type II) with small coastal plains. The second study site is in the sediment-starved Oceanside Littoral Cell (OCL) of

  6. Geophysics Fatally Flawed by False Fundamental Philosophy

    NASA Astrophysics Data System (ADS)

    Myers, L. S.

    2004-05-01

    volcanoes, that enable planetary expansion the same way cranial sutures permit human skulls to grow to maturity. Expansion is shown by the Asian and Australian trenches, from Kamchatka to the Marianas, and from Samoa to the tip of Macquarie Ridge south of New Zealand, that are mirror images of the western coasts of North and South America. This is clear evidence neither the Atlantic nor the Pacific Ocean existed 250 Ma when Earth was much smaller. In just 250 Ma external accretion and internal core expansion increased Earth's diameter from 7640 km to 12,735 km and increased total surface area to 361,060,000 sq. km, the area occupied by today's oceans-oceans that did not exist 250 Ma when Earth was slightly larger than Mars is today \\(6787 km\\). The fallacy of the nebular hypothesis did not become apparent until after Oliver and Isacks introduced the concept of subduction in 1967. Subduction was based on the false assumption that Earth's diameter is constant and unchanging, and spawned the theory of Plate Tectonics that "revolutionized" geophysics in a short period of time-a "revolution" destined for failure. Evidence is presented showing all solar bodies originate as comets \\(fragments of supernovae explosions\\) captured by the Sun that become meteoroids or asteroids by external accretion of meteorites and dust from over 370 known meteor streams.\\(Terentjeva, 1964\\) Accreation replaces the nebular hypothesis and rejuvenates Carey's Earth Expansion theory that, unfortunately, was pushed aside by plate tectonics because it lacked a plausible mechanism. However, expansion carries an ultimate threat to Mankind's tenure on Earth and exploration of Mars as the future home of Mankind takes on added significance.

  7. 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

  8. GEOPHYSICS. Layered deformation in the Taiwan orogen.

    PubMed

    Huang, T-Y; Gung, Y; Kuo, B-Y; Chiao, L-Y; Chen, Y-N

    2015-08-14

    The underthrusting of continental crust during mountain building is an issue of debate for orogens at convergent continental margins. We report three-dimensional seismic anisotropic tomography of Taiwan that shows a nearly 90° rotation of anisotropic fabrics across a 10- to 20-kilometer depth, consistent with the presence of two layers of deformation. The upper crust is dominated by collision-related compressional deformation, whereas the lower crust of Taiwan, mostly the crust of the subducted Eurasian plate, is dominated by convergence-parallel shear deformation. We interpret this lower crustal shearing as driven by the continuous sinking of the Eurasian mantle lithosphere when the surface of the subducted plate is coupled with the orogen. The two-layer deformation clearly defines the role of subduction in the formation of the Taiwan mountain belt.

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

    USGS Publications Warehouse

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

    2002-01-01

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

  10. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  12. Lagrangian Flow networks: a new way to characterize transport and connectivity in geophysical flows

    NASA Astrophysics Data System (ADS)

    Ser-Giacomi, Enrico; Hernandez-Garcia, Emilio; Lopez, Cristobal; Rossi, Vincent; Vasile, Ruggero

    2015-04-01

    Water and air transport are among the basic processes shaping the climate of our planet. Heat and salinity fluxes change sea water density, and thus drive the global thermohaline circulation. Atmospheric winds force the ocean motion, and also transport moisture, heat or chemicals, impacting the regional climate. We describe transport among different regions of the ocean or the atmosphere by flow networks, giving a discrete and robust representation of the fluid advection dynamics. We use network-theory tools to gain insights into transport problem. Local and global features of the networks are extracted from many numerical experiments to give a time averaged description of the system. Classical concepts like dispersion, mixing and connectivity are finally related to a set of network-like objects contributing to build a "dictionary" between network measures and physical quantities in geophysical flows.

  13. 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.

  14. Well casing-based geophysical sensor apparatus, system and method

    DOEpatents

    Daily, William D.

    2010-03-09

    A geophysical sensor apparatus, system, and method for use in, for example, oil well operations, and in particular using a network of sensors emplaced along and outside oil well casings to monitor critical parameters in an oil reservoir and provide geophysical data remote from the wells. Centralizers are affixed to the well casings and the sensors are located in the protective spheres afforded by the centralizers to keep from being damaged during casing emplacement. In this manner, geophysical data may be detected of a sub-surface volume, e.g. an oil reservoir, and transmitted for analysis. Preferably, data from multiple sensor types, such as ERT and seismic data are combined to provide real time knowledge of the reservoir and processes such as primary and secondary oil recovery.

  15. Geophysical Investigations of Archaeological Resources in Southern Idaho

    SciTech Connect

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

    2005-10-01

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

  16. 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.

  17. ``Recycling'' Geophysics: Monitoring and Isotopic Analysis of Engineered Biological Systems

    NASA Astrophysics Data System (ADS)

    Doherty, R.; Singh, K. P.; Ogle, N.; Ntarlagiannis, D.

    2010-12-01

    The emerging sub discipline of biogeophysics has provoked debate on the mechanisms of microbial processes that may contribute to geophysical signatures. At field scales geophysical signatures are often non unique due to the many parameters (physical, chemical, and biological) that are involved. It may be easier to apply geophysical techniques such as electrodic potential (EP), self potential (SP) and induced polarization (IP) to engineered biological systems where there is a degree of control over the design of the physical and chemical domain. Here we present results of a column experiment that was designed to anaerobically biodegrade dissolved organic matter in landfill leachate. The column utilises a recycled porous media (concrete) to help sequester organic carbon. Electrodic potential, self potential and induced polarisation are used in conjunction with chemical and isotopic techniques to monitor the effectiveness of this approach. Preliminary carbon and oxygen isotopic analysis on concrete from the column in contact with leachate show isotopic enrichment suggesting abiotic precipitation of carbonates.

  18. Building Buildings with Triangular Numbers

    ERIC Educational Resources Information Center

    Pagni, David L.

    2006-01-01

    Triangular numbers are used to unravel a new sequence of natural numbers here-to-fore not appearing on the Encyclopedia of Integer Sequences website. Insight is provided on the construction of the sequence using "buildings" as a viewable model of the sequence entries. A step-by-step analysis of the sequence pattern reveals a method for generating…

  19. Building Minds by Block Building.

    ERIC Educational Resources Information Center

    Montopoli, Linda

    Noting that the process of playing with blocks supports the groundwork for learning in every area of a child's growth, this paper discusses specific uses of building blocks in the early childhood curriculum to develop a child's physical, social, emotional, artistic, language, scientific and mathematics growth. The paper outlines the contributions…

  20. 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.

  1. Confidence building

    NASA Astrophysics Data System (ADS)

    Roederer, Juan G.

    Many conferences are being held on confidence building in many countries. Usually they are organized and attended by political scientists and science policy specialists. A remarkable exception, in which the main brainstorming was done by “grass roots” geophysicists, nuclear physicists, engineers and ecologists, was a meeting in July at St. John's College in Santa Fe, N. Mex.The aim of the conference Technology-Based Confidence Building: Energy and Environment was to survey programs of international cooperation in pertinent areas of mutual concern to all nations and to identify new initiatives that could contribute to enhanced international stability, with emphasis on cooperation between the U.S. and U.S.S.R.

  2. 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.

  3. Temperature Dependence of Thermal Expansion for Geophysical Minerals

    NASA Astrophysics Data System (ADS)

    Fang, Zheng-Hua

    2015-07-01

    A simple and straightforward method for evaluating and predicting the volume and volumetric thermal expansivity for geophysical minerals at high temperatures is developed in this paper based on the approximations that the product of the thermal expansion coefficient and the isothermal bulk modulus as well as the isothermal bulk modulus are both linearly dependent with temperature. The tests on four geophysical minerals (MgO, CaO, , and lend strong support to the validity of this method. The analyses and comparisons presented here demonstrate that this method is far better than similar models given by earlier workers.

  4. Unmanned Aircraft Systems for Rapid Near Surface Geophysical Measurements

    NASA Astrophysics Data System (ADS)

    Stoll, J. B.

    2013-08-01

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

  5. Intelligent buildings.

    PubMed

    Williams, W E

    1987-01-01

    The maturing of technologies in computer capabilities, particularly direct digital signals, has provided an exciting variety of new communication and facility control opportunities. These include telecommunications, energy management systems, security systems, office automation systems, local area networks, and video conferencing. New applications are developing continuously. The so-called "intelligent" or "smart" building concept evolves from the development of this advanced technology in building environments. Automation has had a dramatic effect on facility planning. For decades, communications were limited to the telephone, the typewritten message, and copy machines. The office itself and its functions had been essentially unchanged for decades. Office automation systems began to surface during the energy crisis and, although their newer technology was timely, they were, for the most part, designed separately from other new building systems. For example, most mainframe computer systems were originally stand-alone, as were word processing installations. In the last five years, the advances in distributive systems, networking, and personal computer capabilities have provided opportunities to make such dramatic improvements in productivity that the Selectric typewriter has gone from being the most advanced piece of office equipment to nearly total obsolescence.

  6. Contamination source review for Building E1489, Edgewood Area, Aberdeen Proving Ground, Maryland

    SciTech Connect

    Billmark, K.A.; Hayes, D.C.; Draugelis, A.K.

    1995-09-01

    This report was prepared by Argonne National Laboratory (ANL) to document the results of a contamination source review of Building E1489 at the Aberdeen Proving Ground (APG) in Maryland. This report may be used to assist the U.S. Army-in planning for the future use or disposition of this building. The review included a historical records search, physical inspection, photographic documentation, and geophysical investigation. The field investigations were performed in 1994-1995. Building E1489 located in J-Field on the Gunpowder Peninsula in APG`s Edgewood Area housed a power generator that supplied electricity to a nearby observation tower. Building E1489 and the generator were abandoned in 1974, demolished by APG personnel and removed from real estate records. A physical inspection and photographic documentation of Building E1489 were completed by ANL staff during November 1994. In 1994, ANL staff conducted geophysical surveys in the immediate vicinity of Building E1489 by using several nonintrusive methods. Survey results suggest the presence of some underground objects near Building E1489, but they do not provide conclusive evidence of the source of geophysical anomalies observed during the survey. No air monitoring was conducted at the site, and no information on underground storage tanks associated with Building E1489 was available.

  7. 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

  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.

    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

  9. Lewis Fry Richardson Medal Lecture: Motionless travel across scales: Gulliver's scale free geophysics and the Pandora's multifractal box.

    NASA Astrophysics Data System (ADS)

    Schertzer, Daniel

    2015-04-01

    notion of scale had to supersede the Euclidean metrics, which had surprisingly remained a building block of the 'Fractal Geometry of Nature'. Geophysics also required vector or manifold valued cascades, which can be obtained by exploring the Lie algebra of their symmetry generators. Sounds cumbersome? This task turns out to be both stimulating and visually appealing! This approach can be illustrated with the help of the mysterious wobble of Hyperion and gyroscopes, which in a given way puts a damper on the long lasting Lilliputian disagreement between the Big Enders and the Little Enders on determinism and stochastics. These generalizations open ways to understand and simulate (not without aesthetic pleasure!) geophysical turbulence, precipitation, clouds, climate, hazards, resilience and other Wonderland phenomena.

  10. 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

  11. Geodesy on GEMS (GEophysical Monitoring Station)

    NASA Astrophysics Data System (ADS)

    Dehant, V.; Folkner, W.; Le Maistre, S.; Rosenblatt, P.; Yseboodt, M.; Asmar, S.; Marty, J. C.; Banerdt, B.

    2011-10-01

    We propose to use the X-band radio link of the GEMS lander on the surface of Mars with the objective to better determine the rotation and interior structure of Mars. This X-band radio link consists in two-way Doppler measurements from a direct radiolink between the Martian Lander and deep space tracking stations on the Earth. On the basis of these measurements, it will be possible to monitor the lander position relative to the Earth and in turn to improve the determination of the Mars' orientation and rotation parameters (MOP), i.e. the rotation rate variations (or Length of Days LOD), the precession rate and the nutations of the rotation axis, and the orientation of Mars around its rotation axis (polar motion). In this study we perform analytical and numerical simulations of these Doppler measurements in order to quantify the precision that can be obtained on the MOP. These simulations permit to build a strategy to be applied to future data processing in order to improve the precision on the MOP determination. As these parameters are related to the interior of the planet as well as to its seasonal angular momentum changes induced by the CO2 sublimation/condensation process, we further discuss the expected improvement in our knowledge of Mars' interior, i.e. state, size, and composition of the Martian core, and of the CO2 mass budget in the Martian atmosphere and ice caps.

  12. Imaging 3D geological structure of the Mygdonian basin (Northern Greece) with geological numerical modeling and geophysical methods.

    NASA Astrophysics Data System (ADS)

    Cédric, Guyonnet-Benaize; Fabrice, Hollender; Maria, Manakou; Alexandros, Savvaidis; Elena, Zargli; Cécile, Cornou; Nikolaos, Veranis; Dimitrios, Raptakis; Artemios, Atzemoglou; Pierre-Yves, Bard; Nikolaos, Theodulidis; Kyriazis, Pitilakis; Emmanuelle, Chaljub

    2013-04-01

    The Mygdonian basin, located 30 km E-NE close to Thessaloniki, is a typical active tectonic basin, trending E-NW, filled by sediments 200 to 400 m thick. This basin has been chosen as a European experimental site since 1993 (European Commission research projects - EUROSEISTEST). It has been investigated for experimental and theoretical studies on site effects. The Mygdonian basin is currently covered by a permanent seismological network and has been mainly characterized in 2D and 3D with geophysical and geotechnical studies (Bastani et al, 2011; Cadet and Savvaidis, 2011; Gurk et al, 2007; Manakou et al, 2007; Manakou et al, 2010; Pitilakis et al, 1999; Raptakis et al, 2000; Raptakis et al, 2005). All these studies allowed understanding the influence of geological structures and local site conditions on seismic site response. For these reasons, this site has been chosen for a verification exercise for numerical simulations in the framework of an ongoing international collaborative research project (Euroseistest Verification and Validation Project - E2VP). The verification phase has been made using a first 3D geophysical and geotechnical model (Manakou, 2007) about 5 km wide and 15 km long, centered on the Euroseistest site. After this verification phase, it has been decided to update, optimize and extend this model in order to obtain a more detailed model of the 3D geometry of the entire basin, especially the bedrock 3D geometry which can affect drastically the results of numerical simulations for site effect studies. In our study, we build a 3D geological model of the present-day structure of the entire Mygdonian basin. This "precise" model is 12 km wide, 65 km long and is 400 m deep in average. It has been built using geophysical, geotechnical and geological data. The database is heterogeneous and composed of hydrogeological boreholes, seismic refraction surveys, array microtremor measurements, electrical and geotechnical surveys. We propose an integrated

  13. Geophysical fingerprints of shallow cultural structures from microgravity and GPR measurements in the Church of St. George, Svätý Jur, Slovakia

    NASA Astrophysics Data System (ADS)

    Panisova, Jaroslava; Murín, Igor; Pašteka, Roman; Haličková, Jana; Brunčák, Peter; Pohánka, Vladimír; Papčo, Juraj; Milo, Peter

    2016-04-01

    Recording of the historic edifice using the state-of-the-art geodetic and geophysical techniques brings easier visualisation in form of a three-dimensional (3D) model, thus allowing better understanding of its historical construction by the public and non-experts. We have applied this approach at the Church of St. George, one of the most significant religious buildings in south-western Slovakia, which dominates a silhouette of the town Svätý Jur. The geodetic survey allowed to record the actual state of the church. The church exterior was surveyed using a total station. Due to the intricate shape of the interior components of the church, it was decided to use a terrestrial laser scanner to generate the point cloud data, which were processed into floor plan, elevations, sectional 2D drawings and 3D model. The geophysical survey was carried out in the interior of the church in order to identify potential subsurface anthropogenic structures. Microgravity and ground penetrating radar (GPR) methods were selected as the most effective geophysical tools for such task. In microgravity data processing we focused on the calculation and removal of the gravitational effects of the building masses. The main negative gravity anomalies of interest in the nave, which also have been confirmed by GPR measurements, are interpreted as medieval crypts. Another very important outcome of the geophysical survey is the discovery of the west wall foundations of the oldest Romanesque construction. From each geophysical data acquired we derived 3D polygonal models, which are compared to achieve more realistic picture of the subsurface structures. Verification of these structures by means of archaeological excavation has not been carried out yet.

  14. High resolution geophysical prospecting for the delineation of subsurface archaeological objects

    NASA Astrophysics Data System (ADS)

    Niesner, E.; Leonhardt, R.; Scholger, R.

    2009-04-01

    Objects of archaeological interest like foundations of ancient buildings are commonly covered by layers of sediments. Although these layers are often not very thick, these objects are hidden to the eye. Different geophysical methods are available to get more insight into the subsurface, but to get results which are sufficient to the archaeologist; very high resolution has to be achieved. Therefore, and this is common in geophysics, the measurement method and the field parameters had to be optimised for the specific search object. In the forefront of such an investigation prior numerical modelling, collecting of available petrophysical parameters of the typical materials and geologic surroundings and some test profiles are necessary to optimize the field parameters to depth range and resolution. In the specific task presented, foundations of ancient buildings and graves had to be outlined. The results of different methods and the procedures to find the optimum methods and field parameters are presented. The methods from which results are presented are visual and infrared aerial photography, geoelectric mapping and multielectrode geoelectric tomography, magnetic, electromagnetic, SP and susceptibility measurements. A comparison of the results will be shown and the differences will be discussed. In the specific case a special geoelectrical mapping procedure gave the best results. Also infrared airborne photography showed good resolution. Unfortunately the exact location and the dimensions of the objects could not be deduced from the available aerial pictures. Combining these infrared aerial pictures with the results of the ground based geoelectric mapping gives in the specific case the best results. The aerial pictures show indications of the interesting objects and with the geoelectric method the exact location of these foundations could be found and outlined with lot of details. The prospecting method had been applied to some of the remaining foundations of the

  15. Directory of research projects: Planetary geology and geophysics program

    NASA Technical Reports Server (NTRS)

    Holt, Henry (Editor)

    1992-01-01

    Information about currently funded scientific research within the Planetary Geology and Geophysics Program is provided. The directory consists of the proposal summary sheet from each proposal funded under the program during Fiscal Year 1992. The sheets provide information about the research project, including title, principal investigator, institution, summary of research objectives, past accomplishments, and proposed new investigations.

  16. Directory of research projects, 1991. Planetary geology and geophysics program

    NASA Technical Reports Server (NTRS)

    Maxwell, Ted A. (Editor)

    1991-01-01

    Information is provided about currently funded scientific research within the Planetary Geology and Geophysics Program. The directory consists of the proposal summary sheet from each proposal funded by the program during fiscal year 1991. Information is provided on the research topic, principal investigator, institution, summary of research objectives, past accomplishments, and proposed investigators.

  17. COUPLED GEOPHYSICAL-HYDROLOGICAL MODELING OF A CONTROLLED NAPL SPILL

    EPA Science Inventory

    Past studies have shown reasonable sensitivity of geophysical data for detecting or monitoring the movement of non-aqueous phase liquids (NAPLs) in the subsurface. However, heterogeneity in subsurface properties and in NAPL distribution commonly results in non-unique data

    ...

  18. Reports of planetary geology and geophysics program, 1988

    NASA Technical Reports Server (NTRS)

    Holt, Henry E. (Editor)

    1989-01-01

    This is a compilation of abstracts of reports from Principal Investigators of NASA's Planetary Geology and Geophysics Program, Office of Space Science and Applications. The purpose is to document in summary form research work conducted in this program during 1988. Each report reflects significant accomplishments within the area of the author's funded grant or contract.

  19. Reports of Planetary Geology and Geophysics Program, 1986

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Abstracts compiled from reports from Principal Investigators of the NASA Planetary Geology and Geophysics Program, Office of Space Science and Applications are presented. The purpose is to document in summary form work conducted in this program during 1986. Each report reflects significant accomplishments within the area of the author's funded grant or contract.

  20. Hydro-biogeochemical Controls on Geophysical Signatures (Invited)

    NASA Astrophysics Data System (ADS)

    Atekwana, E. A.

    2013-12-01

    Geophysical techniques such as seismic, magnetic and electrical techniques have historically played a major role in oil exploration. Their main use has been for delineation basin geometry, structures and hydrocarbon traps and for understanding the subsurface stratigraphy. Their use for investigating microbial processes has only recently been recognized over the last decade resulting in the development of biogeophysics as a frontier research area which bridges the fields of environmental microbiology, biogeochemistry, geomicrobiology. Recent biogeophysical studies have demonstrated the potential of geophysical technologies to (1) probe the presence of microbial cells and biofilms in subsurface geologic media, (2) investigate the interactions between microorganisms and subsurface geologic media, (3) assess biogeochemical transformations, biomineralization, and biogeochemical reaction rates, and (4) investigate the alteration of physical properties of subsurface geologic media induced by microorganisms. The unique properties of geophysical datasets (e.g. non-invasive data acquisition, spatially continuous properties retrieved) make them attractive for probing microbial processes affecting fate and transport of contaminants. This presentation will provide an updated understanding of major controls on geophysical signatures by highlighting some of the important advancements in biogeophysical studies at hydrocarbon contaminated environments. Important challenges that provide an opportunity for further research in this new field will also be examined.

  1. Geophysical investigations with TOPEX/Poseidon altimetry data

    NASA Technical Reports Server (NTRS)

    Cazenave, Anny; Balmino, G.; Dominh, K.; Lago, B.; Rabinowicz, M.; Biancale, R.; Houry, S.; Okal, E. B.; Diament, M.; Parsons, B.

    1991-01-01

    In the proposed research, TOPEX/POSEIDON altimeter data will be used with Geosat and European Remote Sensing satellite (ERS-1) data to compute global, region, and local oceanic geoid surfaces. These observations will then be analyzed to conduct geophysical studies relative to the structure of the oceanic lithosphere and mantle.

  2. A Geophysical Atlas for Interpretation of Satellite-derived Data

    NASA Technical Reports Server (NTRS)

    Lowman, P. D., Jr. (Editor); Frey, H. V. (Editor); Davis, W. M.; Greenberg, A. P.; Hutchinson, M. K.; Langel, R. A.; Lowrey, B. E.; Marsh, J. G.; Mead, G. D.; Okeefe, J. A.

    1979-01-01

    A compilation of maps of global geophysical and geological data plotted on a common scale and projection is presented. The maps include satellite gravity, magnetic, seismic, volcanic, tectonic activity, and mantle velocity anomaly data. The Bibliographic references for all maps are included.

  3. Addressing the difficulty of changing fields in geophysics

    NASA Astrophysics Data System (ADS)

    Civilini, F.; Savage, M. K.

    2014-12-01

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

  4. Geophysics of an Oceanic Ice Shell on Snowball Earth

    NASA Technical Reports Server (NTRS)

    Gaidos, E. J.

    2000-01-01

    Kirschvink proposed Precambrian low-latitude glaciation could result in an albedo-driven catastrophic runaway to a "Snowball Earth" state in which pack ice up to 1 km thick covered the world ocean. The geophysical state of an ice crust on a Snowball Earth is examined.

  5. Analysis of Publications and Citations from a Geophysics Research Institute.

    ERIC Educational Resources Information Center

    Frohlich, Cliff; Resler, Lynn

    2001-01-01

    Performs an analysis of all 1128 publications produced by scientists during their employment at the University of Texas Institute for Geophysics, thus assessing research performance using as bibliometric indicators such statistics as publications per year, citations per paper, and cited half-lives. Evaluates five different methods for determining…

  6. The International Geophysical Year in Antarctica: Uncommon Collaborations, Unprecedented Results

    ERIC Educational Resources Information Center

    Belanger, Dian Olson

    2004-01-01

    When 1 July 1957 ''dawned'' in the dark of the south polar night, Americans at seven scientific stations scattered across Antarctica officially began systematic, synoptic observations of the air above and ice below. Joining scientists from 11 other countries on the polar continent, they were part of the International Geophysical Year, an 18-month…

  7. 25 CFR 212.56 - Geological and geophysical permits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Geological and geophysical permits. 212.56 Section 212.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS..., authorize the production of, or removal of oil and gas, or geothermal resources, or other minerals...

  8. 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.

  9. Geophysical flows as dynamical systems: the influence of Hide's experiments

    NASA Astrophysics Data System (ADS)

    Ghil, Michael; Read, Peter; Smith, Leonard

    2010-08-01

    Michael Ghil, Peter L Read and Leonard A Smith recount the many and various ways that Raymond Hide has influenced their life and work in geophysical fluid dynamics, meteorology, climatology and planetary sciences, as well as in developing the study of dynamical systems in general.

  10. Geophysical Monitoring of Two types of Subsurface Injection

    EPA Science Inventory

    Nano-scale particles of zero-valent iron (ZVI) were injected into the subsurface at the 100-D area of the DOE Hanford facility. The intent of this iron injection was to repair a gap in the existing in-situ redox manipulation barrier located at the site. A number of geophysical me...

  11. 25 CFR 212.56 - Geological and geophysical permits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 212.56 Section 212.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS..., authorize the production of, or removal of oil and gas, or geothermal resources, or other minerals...

  12. 25 CFR 211.56 - Geological and geophysical permits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Geological and geophysical permits. 211.56 Section 211.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS... contract, or authorize the production of, or removal of oil and gas, geothermal resources, or...

  13. 25 CFR 211.56 - Geological and geophysical permits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Geological and geophysical permits. 211.56 Section 211.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS... contract, or authorize the production of, or removal of oil and gas, geothermal resources, or...

  14. 25 CFR 211.56 - Geological and geophysical permits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Geological and geophysical permits. 211.56 Section 211.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS... contract, or authorize the production of, or removal of oil and gas, geothermal resources, or...

  15. 25 CFR 211.56 - Geological and geophysical permits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 211.56 Section 211.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS... contract, or authorize the production of, or removal of oil and gas, geothermal resources, or...

  16. 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...

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

    SciTech Connect

    Rubin, Yoram

    2001-01-01

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

  18. Geophysical characteristics and crustal structure of greenstone terranes: Canadian Shield

    NASA Technical Reports Server (NTRS)

    Thomas, M. D.; Losier, L.; Thurston, P. C.; Gupta, V. K.; Gibb, R. A.; Grieve, R. A. F.

    1986-01-01

    Geophysical studies in the Canadian Shield have provided some insights into the tectonic setting of greenstone belts. Greenstone belts are not rooted in deep crustal structures. Geophysical techniques consistently indicate that greenstones are restricted to the uppermost 10 km or so of crust and are underlain by geophysically normal crust. Gravity models suggest that granitic elements are similarly restricted, although magnetic modelling suggests possible downward extension to the intermediate discontinuity around approx. 18 km. Seismic evidence demonstrates that steeply-dipping structure, which can be associated with the belts in the upper crust, is not present in the lower crust. Horizontal intermediate discontinuities mapped under adjacent greenstone and granitic components are not noticeably disrupted in the boundary zone. Geophysical evidence points to the presence of discontinuities between greenhouse-granite and adjacent metasedimentary erranes. Measured stratigraphic thicknesses of greenstone belts are often twice or more the vertical thicknesses determined from gravity modelling. Explantations advanced for the discrepancy include stratigraphy repeated by thrust faulting and/or listric normal faulting, mechanisms which are consistent with certain aspects of conceptual models of greenstone development. Where repetition is not a factor the gravity evidence points to removal of the root zones of greenstone belts. For one region, this has been attributed to magmatic stopping during resurgent caldera activity.

  19. Reports of planetary geology and geophysics program, 1987

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This is a compilation of abstracts of reports from Principal Investigators of NASA's PLanetary Geology and Geophysics program, Office of Space Science and Applications. The purpose is to document in summary form research work conducted in this program during 1987. Each report reflects significant accomplishments in the area of the author's funded grant or contract.

  20. 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.

  1. Directory of research projects: Planetary geology and geophysics program

    NASA Technical Reports Server (NTRS)

    Holt, Henry (Editor)

    1990-01-01

    Information about currently funded scientific research within the Planetary Geology and Geophysics Program is provided, including the proposal summary sheet from each proposal funded under the program during fiscal year 1990. Information about the research project, including title, principal investigator, institution, summary of research objectives, past accomplishments, and proposed new investigations is also provided.

  2. The Role of Geophysics in the New Global Tectonics

    ERIC Educational Resources Information Center

    Rudman, Albert J.

    1969-01-01

    Summarizes the developments in geophysics that have led to the concept of the new global tectonics, which attempts to explain such worldwide features as oceanic ridges and trenches, island arcs and young mountain chains, while it develops processes that cause earthquakes, volcanoes and major faulting. Evidence for the hypotheses of continental…

  3. Geophysical Detection of Biomineralization Within Selenium Contaminated Lake Sediment

    NASA Astrophysics Data System (ADS)

    O'Brien, M.; Ntarlagiannis, D.; Slater, L.; Yee, N.

    2006-05-01

    Geophysical measurements during active selenite reduction were made on lake sediment from Belews Lake in North Carolina that was verified to contain indigenous cultures known to precipitate the metalloid selenium. The sediment was wet-packed into columns with a mixture of Ottawa sand (80% sand, 20% sediment) to facilitate flow through the sediment. Electrical geophysical measurements were continually monitored as a selenite medium flowed through the column. Electrical conductivity of the influent and outflow solutions was also monitored and outflow samples, taken twice a day, were used to determine the selenite concentrations reduced within the column. Within a few days of beginning the experiment, the sediment/sand mixture within the column exhibited widespread red discoloration, confirming the microbial reduction of selenite to elemental selenium within the column. The electrical formation factor exhibited a smooth increase in time that we attribute to the continual precipitation of selenium biominerals. The geophysical dataset provides a novel means to ascertain rates of biomineralization within the column; information that is difficult to extract from aqueous or solid phase chemistry. The geophysical data indicate that most of the microbial activity occurred within the first 5 days of the experiment.

  4. Geophysical data fusion for subsurface imaging. Phase 1

    SciTech Connect

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

    1993-08-01

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

  5. Reports of planetary geology and geophysics program, 1986

    SciTech Connect

    Not Available

    1987-05-01

    Abstracts compiled from reports from Principal Investigators of the NASA Planetary Geology and Geophysics Program, Office of Space Science and Applications are presented. The purpose is to document in summary form work conducted in this program during 1986. Each report reflects significant accomplishments within the area of the author's funded grant or contract.

  6. 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

  7. Linking geophysics and soil function modelling - two examples

    NASA Astrophysics Data System (ADS)

    Krüger, J.; Franko, U.; Werban, U.; Dietrich, P.; Behrens, T.; Schmidt, K.; Fank, J.; Kroulik, M.

    2011-12-01

    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. The iSOIL project aims at reliable mapping of soil properties and soil functions with various methods including geophysical, spectroscopic and monitoring techniques. The general procedure contains three steps (i) geophysical monitoring, (ii) generation of soil property maps and (iii) process modelling. The objective of this work is to demonstrate the methodological procedure on two different examples. Example A focuses on the turnover conditions for soil organic matter (SOM) since many soil functions in a direct or indirect way depend on SOM and SOM depletion is amongst the worst soil threats. Example B deals with the dynamics of soil water and the direct influence on crop biomass production. The applied CANDY model (Franko et al. 1995) was developed to describe dynamics of soil organic matter and mineral nitrogen as well as soil water and temperature. The new module PLUS extends CANDY to simulate crop biomass production based on environmental influences (Krüger et al. 2011). The methodological procedure of example A illustrates a model application for a field site in the Czech Republic using generated soil maps from combined geophysical data. Modelling requires a complete set of soil parameters. Combining measured soil properties and data of geophysical measurements (electrical conductivity and gamma spectrometry) is the basis for digital soil mapping which provided data about clay, silt and sand as well as SOC content. With these data pedotransfer functions produce detailed soil input data (e.g. bulk and particle density, field capacity, wilting point, saturated conductivity) for the rooted soil profile. CANDY calculated different indicators for SOM and gave hints about

  8. Geophysical Methods for Investigating Ground-Water Recharge

    USGS Publications Warehouse

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

    2007-01-01

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

  9. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  10. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  11. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  12. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  13. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-A (Solid-Earth Geophysics, Solar Terrestrial Physics, and Glaciology). (a) Geophysical and solar... geological data, including data on heat flow, cores, samples, and sediments. (2) Solar-Terrestrial...

  14. 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

  15. Geophysical monitoring of a field-scale biostimulation pilot project

    USGS Publications Warehouse

    Lane, J.W.; Day-Lewis, F. D.; Casey, C.C.

    2006-01-01

    The USGS conducted a geophysical investigation in support of a U.S. Naval Facilities Engineering Command, Southern Division field-scale biostimulation pilot project at Anoka County Riverfront Park (ACP), downgradient of the Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota. The goal of the pilot project is to evaluate subsurface injection of vegetable oil emulsion (VOE) to stimulate microbial degradation of chlorinated hydrocarbons. To monitor the emplacement and movement of the VOE and changes in water chemistry resulting from VOE dissolution and/or enhanced biological activity, the USGS acquired cross-hole radar zero-offset profiles, traveltime tomograms, and borehole geophysical logs during five site visits over 1.5 years. Analysis of pre- and postinjection data sets using petrophysical models developed to estimate VOE saturation and changes in total dissolved solids provides insights into the spatial and temporal distribution of VOE and ground water with altered chemistry. Radar slowness-difference tomograms and zero-offset slowness profiles indicate that the VOE remained close to the injection wells, whereas radar attenuation profiles and electromagnetic induction logs indicate that bulk electrical conductivity increased downgradient of the injection zone, diagnostic of changing water chemistry. Geophysical logs indicate that some screened intervals were located above or below zones of elevated dissolved solids; hence, the geophysical data provide a broader context for interpretation of water samples and evaluation of the biostimulation effort. Our results include (1) demonstration of field and data analysis methods for geophysical monitoring of VOE biostimulation and (2) site-specific insights into the spatial and temporal distributions of VOE at the ACP. ?? 2006 National Ground Water Association.

  16. 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.

  17. 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

  18. Information-Theoretic Perspectives on Geophysical Models

    NASA Astrophysics Data System (ADS)

    Nearing, Grey

    2016-04-01

    To test any hypothesis about any dynamic system, it is necessary to build a model that places that hypothesis into the context of everything else that we know about the system: initial and boundary conditions and interactions between various governing processes (Hempel and Oppenheim, 1948, Cartwright, 1983). No hypothesis can be tested in isolation, and no hypothesis can be tested without a model (for a geoscience-related discussion see Clark et al., 2011). Science is (currently) fundamentally reductionist in the sense that we seek some small set of governing principles that can explain all phenomena in the universe, and such laws are ontological in the sense that they describe the object under investigation (Davies, 1990 gives several competing perspectives on this claim). However, since we cannot build perfect models of complex systems, any model that does not also contain an epistemological component (i.e., a statement, like a probability distribution, that refers directly to the quality of of the information from the model) is falsified immediately (in the sense of Popper, 2002) given only a small number of observations. Models necessarily contain both ontological and epistemological components, and what this means is that the purpose of any robust scientific method is to measure the amount and quality of information provided by models. I believe that any viable philosophy of science must be reducible to this statement. The first step toward a unified theory of scientific models (and therefore a complete philosophy of science) is a quantitative language that applies to both ontological and epistemological questions. Information theory is one such language: Cox' (1946) theorem (see Van Horn, 2003) tells us that probability theory is the (only) calculus that is consistent with Classical Logic (Jaynes, 2003; chapter 1), and information theory is simply the integration of convex transforms of probability ratios (integration reduces density functions to scalar

  19. Hydro/Engineering Geophysical Parameters and Design Response Spectrum for Sustainable Development in Ras Muhammed National Park, Sinai

    NASA Astrophysics Data System (ADS)

    Khalil, Mohamed H.; Gamal, Mohamed A.

    2016-06-01

    The Egyptian government is preparing a sustainable development master plan for the Ras Muhammed National Park (RMNP), south Sinai. Noteworthy, the scarcity of the freshwater resources and close proximity to the active seismic zones of the Gulf of Aqaba implicate geophysical investigations for the fresh groundwater aquifers and construct a design response spectrum, respectively. Accordingly, 14 VESs, hydro/engineering geophysical analysis, pumping tests, downhole seismic test, a design response spectrum for buildings, and borehole data were carried out in the study area. The unconfined freshwater aquifer was effectively depicted with true resistivities, thickness, and EC ranged from 56 to 135 Ω m, 11 to 112 m, and 1.4 to 7.1 mS/m, respectively. The Northeastern part was characterized by higher aquifer potentiality, where coarser grains size, highest thickness (112 m), high true resistivity (135 Ω m), groundwater flow (0.074 m3/day), tortuosity (1.293-1.312), formation resistivity factor (4.1-4.6), and storativity (0.281-0.276). An increase in pumping rate was accompanied by an increase in well loss, increase in aquifer losses, decrease in well specific capacity, and decrease in well efficiency. Design response spectrum prognosticated the short buildings (<7 floors) in RMNP to be suffering from a high peak horizontal acceleration and shear forces for acceleration between 0.25 and 0.35 g. Therefore, appropriate detailing of shear reinforcement is indispensable to reduce the risk of structural damages at RMNP.

  20. A thermodynamic database for geophysical applications

    NASA Astrophysics Data System (ADS)

    Saxena, S. K.

    2013-12-01

    Several thermodynamic databases are available for calculation of equilibrium reference state of the model earth. Prominent among these are the data bases of (a) SLB (1), (b) HP (2) and (c) FSPW (3). The two major problems, as discussed in a meeting of the database scientists (4), lie in the formulation of solid solutions and equations of state. The models adopted in databases (1) and (2) do not account for multi-components in natural solids and the sub-lattice or compound-energy models used in (3) require lot of fictive compound and mixing energy data for which there is no present ongoing attempt. The EOS formulation in (1) is based on Mie-Gruneisen equation of state and in (2) on modification of Tait EOS with limited parameters. The database (3) adopted the Birch-Murnaghan EOS and used it for high temperature by making compressibility a function of temperature. The (2) and (3) models lead to physically unacceptable values of entropy and heat capacity at extreme conditions. The problem is as much associated with the EOS formulation as with the adoption of a heat capacity change with temperature at 1 bar as discussed by Brosh (5). None of the databases (1), (2) or (3) include the database on multicomponent fluid at extreme conditions. These problems have been addressed in the new database modified after (3). It retains the solution models for solids as in (3) and adds the Brosh Model (5) for solid solutions and the Belonoshko et al (6) model for 13-component C-H-O-S fluid. The Superfluid model builds on the combination of experimental data on pure and mixed fluids at temperatures lower than 1000 K over several kilobars and molecular dynamics generated data at extreme conditions and has been found to be consistent with all the recent experimental data. New high pressure experiments on dissociation of volatile containing solids using laser- and externally-heated DAC are being conducted to obtain new pressure-volume-temperature data on fluids to extend the current kb

  1. Commercial Buildings Energy Consumption Survey - Office Buildings

    EIA Publications

    2010-01-01

    Provides an in-depth look at this building type as reported in the 2003 Commercial Buildings Energy Consumption Survey. Office buildings are the most common type of commercial building and they consumed more than 17% of all energy in the commercial buildings sector in 2003. This special report provides characteristics and energy consumption data by type of office building (e.g. administrative office, government office, medical office) and information on some of the types of equipment found in office buildings: heating and cooling equipment, computers, servers, printers, and photocopiers.

  2. Coupled thermal and geophysical modelling for monitoring of permafrost

    NASA Astrophysics Data System (ADS)

    Rings, Jörg; Scherler, Martin; Hauck, Christian

    2010-05-01

    Geophysical methods, and especially the Electrical Resistivity Tomography (ERT) method, are being recognised as standard tools for the detection and monitoring of permafrost. Recent advances in automated data acquisition and processing have made their application worthwhile for continuous monitoring systems even in harsh and heterogeneous terrain. ERT yields 2- and 3-dimensional data of the subsurface and is sensitive to the unfrozen water and ice content, which is complementary to the 1-dimensional temperature measurements conducted in boreholes. For future autonomous and widespread monitoring systems for permafrost, a purely geophysical approach is envisaged, because the low costs and minimal disturbance of the system to be monitored is one of the major advantages of geophysics as opposed to boreholes. However, the link between the indirectly measured geophysical property (e.g. electrical resistivity in case of ERT) of the subsurface and temperature is often non-trivial and cannot be determined without ground truth data from boreholes or extensive laboratory calibration. In this contribution, we introduce a Bayesian filtering approach of coupled geophysical and thermal modelling to predict subsurface temperatures based on ERT monitoring data without the need for borehole or laboratory data. We use sequential Bayesian filtering or particle filtering, which has the advantage of continuously providing probability distributions of state (temperature) and parameters (e.g. the link between resistivity and temperature) whenever measurements become available. A particle filter approximates these distributions by a set of discrete, weighted particles. For each particle, initial state and parameter are drawn from prior distributions and thermal conduction is modelled independently. The modelled change in temperature is transferred to change in resistivity by a linear relation, and an ERT forward model is used to simulate the system response. Then, the particles are

  3. 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

  4. CzechGeo/EPOS - Distributed System of Permanent Observatory Measurements and Temporary Monitoring of Geophysical Fields

    NASA Astrophysics Data System (ADS)

    Hejda, Pavel; Čápová, Dana; Fischer, Tomáš; Kaláb, Zdeněk; Kostelecký, Jakub; Plicka, Vladimír; Stemberk, Josef; Špaček, Petr

    2016-04-01

    CzechGeo/EPOS is a distributed network of geoscience observations operated by the Czech research institutions and universities. The system consists of permanent observatories usually incorporated in global data networks, local stations or networks in areas significant in the long-term for basic research or applications and mobile stations which serve for repeated observations at selected points, or for field measurements, usually within the scope of large international projects. CzechGeo/EPOS is closely connected with the large European research infrastructure EPOS (European Plate Observing System) and its service covers continuous monitoring of geophysical fields on Czech territory and in selected areas abroad via long uninterrupted series of measurements on fixed sites, which are vital for understanding of Earth interior processes. The infrastructure is organized in 5 sections: Seismology, GNSS and Gravimetry, Geodynamics, Geomagnetism, Geological and Geophysical Databases. CzechGeo/EPOS provides user-friendly data access to global or regional data bases/repositories, including real-time data access whenever possible, transmits access to high-level products (e.g. waveform data, seismological bulletins and regional catalogues, geomagnetic indices) and integrates data in the frame of the Implementation Phase of the EPOS Project. CzechGeo/EPOS involves nearly all observational activities related to the solid Earth carried out by the Czech geoscience institutions and thus is indispensable for any geoscience research on our territory. Through participation in more than twenty global or regional networks CzechGeo/EPOS builds up close cooperation with European partners and contributes substantially to better understanding of the processes in the Earth's interior.

  5. Integrated Geophysical and Archaeological investigations to study the site of Aquinum (Frosinone, Italy)

    NASA Astrophysics Data System (ADS)

    Piro, Salvatore; Ceraudo, Giuseppe; Zamuner, Daniela

    2010-05-01

    To enhance the knowledge finalised to the location and conservation of the unknown buried structures below the actual studied levels, in the territory of the Ancient Aquinum (Frosinone, Italy) a scientific collaboration, inside the "Ager Aquinas Project" between the University of Salento (Department of Cultural Heritage - Laboratory of Ancient Topography and Photogrammetry) and the Institute of Technologies Applied to Cultural Heritage (ITABC-C.N.R.) has been developed, during 2008-2009 and it is still in progress. The site which is the subject of this paper had been identified in the past through air photo interpretation of vertical historical coverage and field - walking surveys. Ancient Aquinum is characterised by two main aspects: the first depends by the presence of a very big defence-system with mighty walls and large ditch; the second characteristic is the presence or regular but not orthogonal road - system of the town, bordered by an unusual parallelogram shape of the blocks. With the results obtained after the elaborations of the first aerial data sets and field surveys, has been possible to map the main town - planning, drawing the main road system inside and outside the town. Although the analysis of the air photo evidence allowed the global interpretation of the site, it was not possible to reconstruct the archaeological evidences in the central portion of the town. Therefore the Project, during 2008, started with new acquisition and elaboration of aerial photos, field-walking surveys and GPR surveys with the aim to better define the urban plan of the central portion of the ancient town. The location, depth, and size of the buried buildings were effectively estimated from non-destructive remote sensing with a gradiometric and ground-penetrating radar systems. Recent archaeological excavations made (by Prof. Giuseppe Ceraudo - University of Salento, Lecce) during the summer 2009, have confirmed the structures individuated with the geophysical methods

  6. Mapping Mortality and Geophysical Features During a Heat Wave in Los Angeles County, California

    NASA Astrophysics Data System (ADS)

    Joe, L.

    2011-12-01

    With climate change, heat waves are predicted to increase in intensity and duration, particularly in areas where they have occurred previously. Human mortality increases during heat waves, and that increase may vary by community due to a variety of factors including differing geophysical and built environment features. In July 2006, California experienced a statewide heat wave that was unprecedented in duration, lasting 10 days in much of the state, and longer in some areas. To explore heat wave health impacts by community, we focused on Los Angeles County, selected for its urban density and diverse social and geographic landscapes. We calculated the ratio of deaths during the heat wave period (July 15 - Aug 1) to deaths in reference days from the non-heat wave period in the same summer. The raw and empirical Bayes smoothed rate ratios were mapped by census tract (average population size approximately 5000). We then used spatial scanning procedures to identify census tract clusters of high and low mortality. Onto the heat mortality maps, we overlaid such geographic and built environment characteristics as elevation, recordings from temperature monitors, building climate zone boundaries, and air conditioning use. In this presentation, we will discuss the potential relationship between mortality and geophysical and built environment features. In the future, we will expand this analysis statewide and share our findings with local stakeholders to explore factors which may make their communities more resilient (low health impact) or vulnerable (high health impact). Ultimately, knowledge of vulnerability and resiliency factors may inform future applied research and climate change mitigation and adaptation strategies. Authors: Lauren Joe, Daniel Smith, Svetlana Smorodinksy, Sumi Hoshiko, Martha Harnly Environmental Health Investigations Branch, California Department of Public Health

  7. Peat Depth Assessment Using Airborne Geophysical Data for Carbon Stock Modelling

    NASA Astrophysics Data System (ADS)

    Keaney, Antoinette; McKinley, Jennifer; Ruffell, Alastair; Robinson, Martin; Graham, Conor; Hodgson, Jim; Desissa, Mohammednur

    2013-04-01

    The Kyoto Agreement demands that all signatory countries have an inventory of their carbon stock, plus possible future changes to this store. This is particularly important for Ireland, where some 16% of the surface is covered by peat bog. Estimates of soil carbon stores are a key component of the required annual returns made by the Irish and UK governments to the Intergovernmental Panel on Climate Change. Saturated peat attenuates gamma-radiation from underlying rocks. This effect can be used to estimate the thickness of peat, within certain limits. This project examines this relationship between peat depth and gamma-radiation using airborne geophysical data generated by the Tellus Survey and newly acquired data collected as part of the EU-funded Tellus Border project, together encompassing Northern Ireland and the border area of the Republic of Ireland. Selected peat bog sites are used to ground truth and evaluate the use of airborne geophysical (radiometric and electromagnetic) data and validate modelled estimates of soil carbon, peat volume and depth to bedrock. Data from two test line sites are presented: one in Bundoran, County Donegal and a second line in Sliabh Beagh, County Monaghan. The plane flew over these areas at different times of the year and at a series of different elevations allowing the data to be assessed temporally with different soil/peat saturation levels. On the ground these flight test lines cover varying surface land use zones allowing future extrapolation of data from the sites. This research applies spatial statistical techniques, including uncertainty estimation in geostatistical prediction and simulation, to investigate and model the use of airborne geophysical data to examine the relationship between reduced radioactivity and peat depth. Ground truthing at test line locations and selected peat bog sites involves use of ground penetrating radar, terrestrial LiDAR, peat depth probing, magnetometry, resistivity, handheld gamma

  8. Building energy analysis tool

    DOEpatents

    Brackney, Larry; Parker, Andrew; Long, Nicholas; Metzger, Ian; Dean, Jesse; Lisell, Lars

    2016-04-12

    A building energy analysis system includes a building component library configured to store a plurality of building components, a modeling tool configured to access the building component library and create a building model of a building under analysis using building spatial data and using selected building components of the plurality of building components stored in the building component library, a building analysis engine configured to operate the building model and generate a baseline energy model of the building under analysis and further configured to apply one or more energy conservation measures to the baseline energy model in order to generate one or more corresponding optimized energy models, and a recommendation tool configured to assess the one or more optimized energy models against the baseline energy model and generate recommendations for substitute building components or modifications.

  9. Alternative experiments using the geophysical fluid flow cell

    NASA Technical Reports Server (NTRS)

    Hart, J. E.

    1984-01-01

    This study addresses the possibility of doing large scale dynamics experiments using the Geophysical Fluid Flow Cell. In particular, cases where the forcing generates a statically stable stratification almost everywhere in the spherical shell are evaluated. This situation is typical of the Earth's atmosphere and oceans. By calculating the strongest meridional circulation expected in the spacelab experiments, and testing its stability using quasi-geostrophic stability theory, it is shown that strongly nonlinear baroclinic waves on a zonally symmetric modified thermal wind will not occur. The Geophysical Fluid Flow Cell does not have a deep enough fluid layer to permit useful studies of large scale planetary wave processes arising from instability. It is argued, however, that by introducing suitable meridional barriers, a significant contribution to the understanding of the oceanic thermocline problem could be made.

  10. Geophysical data fusion for subsurface imaging. Final report

    SciTech Connect

    1995-10-01

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

  11. Dunlop receives European Geophysical Society's Néel Medal

    NASA Astrophysics Data System (ADS)

    Tauxe, Lisa

    David J. Dunlop of the Physics Department and Erindale College at the University of Toronto has been awarded the 1999 Louis Néel Medal of the European Geophysical Society (EGS) for “authoritative contributions to rock magnetism, setting the standards for future decades.” The medal will be presented to Dunlop in April in a special ceremony at the Nederlands Congresbebouw in The Hague, The Netherlands, during the 24th General Assembly of the EGS.The Néel Medal is awarded by the Solid Earth Geophysics section of EGS in recognition of the scientific achievements of Louis Néel, who shared the 1970 Nobel Prize in Physics for his fundamental discoveries in magnetism.The medal is awarded “for outstanding achievements in the fertilization of the Earth Sciences by the transfer and application of fundamental theory and/or experimental techniques of solid state physics, defined in its broadest sense.”

  12. Structure-coupled multiphysics imaging in geophysical sciences

    NASA Astrophysics Data System (ADS)

    Gallardo, Luis A.; Meju, Max A.

    2011-03-01

    Multiphysics imaging or data inversion is of growing importance in many branches of science and engineering. In geophysical sciences, there is a need for combining information from multiple images acquired using different imaging devices and/or modalities because of the potential for accurate predictions. The major challenges are how to combine disparate data from unrelated physical phenomena, taking into account the different spatial scales of the measurement devices, model complexities, and how to quantify the associated uncertainties. This review paper summarizes the role played by the structural gradients-based approach for coupling fundamentally different physical fields in (mainly) geophysical inversion, develops further understanding of this approach to guide newcomers to the field, and defines the main challenges and directions for future research that may be useful in other fields of science and engineering.

  13. 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.

  14. Comparison of different models of geophysical excitation in nutation

    NASA Astrophysics Data System (ADS)

    Ron, Cyril; Vondrák, Jan

    2015-04-01

    Celestial pole offsets caused by the excitations of geophysical fluids (atmosphere, ocean) and geomagnetic fields (geomagnetic jerks) are computed for a non-rigid Earth model to account for the realistic Earth's response by using the integration of the broad-band Liouville equations. The results are compared with the celestial pole offsets observed by Very Long-Baseline Interferometry. In our previous study we demonstrated that the application of a synthetic excitation in the epoch of the geomagnetic jerks improves significantly the agreement between the integrated and observed celestial pole offsets. In the presented study we focus on the analysis of differencies between the integrated series excited by different models of geophysical fluids, the U.S. model NCEP/NCAR and the European models ERA supplemented with the ocean model OMCT provided by GFZ Potsdam.

  15. Simulated geophysical monitoring of radioactive waste repository barriers

    NASA Astrophysics Data System (ADS)

    Biryukov, Anton

    Estimation of attenuation of the elastic waves in clays and high clay-content rocks is important for the quality of geophysical methods relying on processing the recorded waveforms. Time-lapse imaging is planned to be employed for monitoring of the condition of high-radioactive waste repositories. Engineers can analyze and optimize configuration of the monitoring system using numerical modelling tools. The reliability of modeling requires proper calibration. The purpose of this thesis is threefold: (i) propose a calibration methodology for the wave propagation tools based on the experimental data, (ii) estimate the attenuation in bentonite as a function of temperature and water content, and (iii) investigate the feasibility of active sonic monitoring of the engineered barriers. The results suggest that pronounced inelastic behavior of bentonite has to be taken into account in geophysical modeling and analysis. The repository--scale models confirm that active sonic monitoring is capable of depicting physical changes in the bentonite barrier.

  16. The solid earth: An introduction to global geophysics

    SciTech Connect

    Fowler, C.M.R.

    1990-01-01

    This book addresses major topics to be presented in a modern overview course. These topics include terrestrial seismology, gravity, earth's magnetic field and paleomagnetism, radiometric age dating, and heat flow. All are related throughout to the structure and dynamics of the interior of the earth, plate tectonics (including the geometry of tectonics on a sphere), and the nature of the continental and into such aspects as reflection coefficients and Zoeppritz equations, velocity analysis, migration, and Fresnel zone limitation on resolution. Appendices treat the elastic wave equations, inversion of earthquake time-distance curves, and a glossary of geological and geophysical terms. After noting that the book is intended for both geologists and physicists, as well as those marrying the disciplines into geophysics, the author adds that most geophysicists look for oil.

  17. MPDATA: A positive definite solver for geophysical flows

    SciTech Connect

    Smolarkiewicz, P.K.; Margolin, L.G.

    1997-03-01

    This article is a review of MPDATA, a class of methods for the numerical simulation of advection based on the sign-preserving properties of upstream differencing. MPDATA was designed originally as an inexpensive alternative to flux-limited schemes for evaluating the transport of nonnegative thermodynamic variables (such as liquid water or water vapour) in atmospheric models. During the last decade, MPDATA has evolved from a simple advection scheme to a general approach for integrating the conservation laws of geophysical fluids on micro-to-planetary scales. The purpose of this paper is to summarize the basic concepts leading to a family of MPDATA schemes, review the existing MPDATA options, as well as to demonstrate the efficacy of the approach using diverse examples of complex geophysical flows.

  18. MPDATA: A positive definite solver for geophysical flows

    SciTech Connect

    Smolarkiewicz, P.K.; Margolin, L.G.

    1997-12-31

    This paper is a review of MPDATA, a class of methods for the numerical simulation of advection based on the sign-preserving properties of upstream differencing. MPDATA was designed originally as an inexpensive alternative to flux-limited schemes for evaluating the transport of nonnegative thermodynamic variables (such as liquid water or water vapor) in atmospheric models. During the last decade, MPDATA has evolved from a simple advection scheme to a general approach for integrating the conservation laws of geophysical fluids on micro-to-planetary scales. The purpose of this paper is to summarize the basic concepts leading to a family of MPDATA schemes, review the existing MPDATA options, as well as to demonstrate the efficacy of the approach using diverse examples of complex geophysical flows.

  19. A Geophysical Fluid Dynamics Lab Founded by Undergraduate Students

    NASA Astrophysics Data System (ADS)

    Sun, Shiwei; Fu, Hao; Pu, Yunjiao; Liu, Mingrui; Feng, Zhiming; Han, Yilun; Zhou, Ang; Zhuo, Jingyi; Hu, Yue; Wang, Ruoyu; Wu, Nana; Xiang, Zixuan; Xi, Jing; Jappar, Saltanat; Yin, Jingnan; Li, Congyuan; Song, Jinjie; Zhou, Bowen; Wang, Yuan

    2016-11-01

    An atmospheric and oceanic fluid dynamics lab has been established by a group of undergraduate students in the School of Atmospheric Sciences at Nanjing University. A series of classical experiments have been conducted including Taylor column, topographic Rossby waves, and propagating density currents. With very limited funding, all instruments were designed and assembled by students. Their hands-on experimental abilities and understanding of the fundamental theories of geophysical fluid dynamics are greatly enhanced. The students work in groups on a dedicated experiment. A student project on rotating convection was even presented in APS DFD fall meeting last year. This year, we present some new laboratory demonstrative experiments of geophysical flow and introduce how they are incorporated in the undergraduate courseswork. Funding: "National Science Talent Training Project (J1103410)" and "LMSWE Lab Funding No. 14380001".

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

    SciTech Connect

    1995-12-31

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

  1. Integrated software framework for processing of geophysical data

    NASA Astrophysics Data System (ADS)

    Chubak, Glenn; Morozov, Igor

    2006-07-01

    We present an integrated software framework for geophysical data processing, based on an updated seismic data processing program package originally developed at the Program for Crustal Studies at the University of Wyoming. Unlike other systems, this processing monitor supports structured multi-component seismic data streams, multi-dimensional data traces, and employs a unique backpropagation execution logic. This results in an unusual flexibility of processing, allowing the system to handle nearly any geophysical data. A modern and feature-rich graphical user interface (GUI) was developed for the system, allowing editing and submission of processing flows and interaction with running jobs. Multiple jobs can be executed in a distributed multi-processor networks and controlled from the same GUI. Jobs, in their turn, can also be parallelized to take advantage of parallel processing environments, such as local area networks and Beowulf clusters.

  2. Building America

    SciTech Connect

    Brad Oberg

    2010-12-31

    Builders generally use a 'spec and purchase' business management system (BMS) when implementing energy efficiency. A BMS is the overall operational and organizational systems and strategies that a builder uses to set up and run its company. This type of BMS treats building performance as a simple technology swap (e.g. a tank water heater to a tankless water heater) and typically compartmentalizes energy efficiency within one or two groups in the organization (e.g. purchasing and construction). While certain tools, such as details, checklists, and scopes of work, can assist builders in managing the quality of the construction of higher performance homes, they do nothing to address the underlying operational strategies and issues related to change management that builders face when they make high performance homes a core part of their mission. To achieve the systems integration necessary for attaining 40% + levels of energy efficiency, while capturing the cost tradeoffs, builders must use a 'systems approach' BMS, rather than a 'spec and purchase' BMS. The following attributes are inherent in a systems approach BMS; they are also generally seen in quality management systems (QMS), such as the National Housing Quality Certification program: Cultural and corporate alignment, Clear intent for quality and performance, Increased collaboration across internal and external teams, Better communication practices and systems, Disciplined approach to quality control, Measurement and verification of performance, Continuous feedback and improvement, and Whole house integrated design and specification.

  3. Geophysical Monitoring for Climatic Change number 9. Summary report 1980

    SciTech Connect

    DeLuisi, J.J.

    1981-12-01

    This document presents a summary of the research operations and accomplishments by the Geophysical Monitoring for Climatic Change (GMCC) program and by outside investigators working cooperatively with GMCC in 1980. It includes descriptions of management and operations at GMCC's four baseline sites, scientific data from the measurement projects, conclusions from analyses of data and recent basic research achievements. The four observatories are located in Barrow, Alaska; Mauna Loa, Hawaii; American Samoa; and South Pole.

  4. Geophysical Characterization and Monitoring for the Frio Pilot Test

    NASA Astrophysics Data System (ADS)

    Myer, L. R.; Hovorka, S.; Hoversten, G.; Fouad, K.; Holtz, M.

    2003-12-01

    The Frio Pilot test involves injection of approximately 3000 tons of CO2 into the brine-saturated Frio formation at a depth of approximately 1500 m at a test site located northeast of Houston. The CO2 is injected from a new well drilled for the test while an existing well provides subsurface access for monitoring. Geophysical data for characterization included 3-D surface seismic and well logs, which were available because of the extensive oil and gas exploration and production in the area. Seismic interpretation coupled with petrophysical analyses and other geologic data showed that the test site is located in a small fault block off the flank of a salt dome. The injection interval consists of alternating layers of sand and shale, with sand layer thickness on the order of 10 m, overlain by the 75 m thick Anahuac shale. Well logs in the new well provide data to confirm test site stratigraphy as well as data needed for interpretation of geophysical monitoring measurements. Geophysical monitoring involves time-lapse measurements, incorporating both surface and borehole techniques. Selection of techniques was aided by modeling in which reservoir simulation predicted fluid distributions, which were then input to geophysical models to predict performance of candidate techniques. Interpretation of crosswell seismic with appropriate rock physics models can potentially provide quantitative information on CO2 saturation between boreholes. Vertical seismic profiling will be used to map the areal distribution of the plume. Low resolution but inexpensive streaming potential measurements will also be carried out to sense the advancing CO2 front.

  5. Progress in geophysical aspects of the rotation of the earth

    NASA Technical Reports Server (NTRS)

    Lambeck, K.

    1978-01-01

    The geophysical causes and consequences of the Earth's rotation are reviewed. Specific topics covered include: (1) the motion of the rotation axis in space, precession and nutation; (2) the motion of the rotation axis relative to the Earth, polar motion; and (3) the rate of rotation about this axis, or changes in the length of day. Secular decrease in obliquity and evolution of the Earth-Moon system are also discussed.

  6. 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

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

    DOEpatents

    Daily, Michael R.; Rohde, Steven B.; Novak, James L.

    2008-05-20

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

  8. 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.

  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. 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.

  11. Catastrophes of Every Ilk at The Geophysics Fest

    NASA Astrophysics Data System (ADS)

    Kerr, Richard A.

    1993-01-01

    At the annual meeting of the American Geophysics Union (AGU) in San Francisco on 7-11 December, catastrophes came in all sizes. On the molecular level, atmospheric chemists had news about the manmade compounds destroying the ozone shield-and for once the news was good. More earthshaking were signs of long-distance connections among earthquakes. And from farther afield came reports of odd-shaped debris from mini-planet collisions.

  12. United States Air Force Geophysics Scholar Program, 1982-1983.

    DTIC Science & Technology

    1984-03-01

    gold surface with < 0.1 eV of kinectic energy . The beam direction will be maintained at low energies by using a set of Helmholtz coils surrounding the...NATIONAL BUREAU Of STANDARDS 1963 A t II 1982-1983 LSAF/SCEEE AIR FORCE GEOPHYSICS SCHOLAR PROGRAM conducted by Southeastern Center for Electrical ...Bolling Air Force Base Washington D.C. by Southeastern Center for Electrical Engineering Education March 1984 IL ’a’ [ .1 Ai UNCLASSIFIED SECURITY

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  14. Space Geodesy Monitoring Mass Transport in Global Geophysical Fluids

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

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

  15. 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.

  16. Bringing 3D Printing to Geophysical Science Education

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  17. 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.

  18. Determining Aquifer Storage Properties Using Borehole Geophysical Data

    NASA Astrophysics Data System (ADS)

    Wempe, W.; Clayton, N.; Coulibaly, K.

    2006-12-01

    Specific yield and specific storage are essential parameters for groundwater management planning. These storage properties can be determined using a number of methods, however they are typically interpreted from multi-well aquifer pump tests. The interpretation of storage properties using pump tests can be strongly influenced and biased by small-scale hydrostratigraphic heterogeneities and boundary effects. We investigate using high resolution geophysical data collected in boreholes to provide depth-continuous logs of storage properties within heterogeneous aquifers. The advantage of using borehole geophysical data to interpret storage properties is that the estimates are unaffected by boundary conditions and that small-scale heterogeneities around the borehole can be resolved and then incorporated in more advanced interpretations of pump tests, which sample away from the borehole wall. This improved interpretation of storage properties ultimately leads to improved groundwater management planning and optimal well design, thus reducing economic risks associated with high cost production or aquifer storage and recovery wells. Our interpretations of specific yield are based on measurements of effective porosity that are made using borehole nuclear magnetic resonance tools and our interpretations of specific storage are based on measurements of aquifer compressibility that are made using borehole dipole shear sonic tools. With several case studies, we demonstrate how to interpret storage properties from these types of borehole geophysical data and show the benefits of incorporating the heterogeneity of storage properties in groundwater management planning.

  19. 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.

  20. 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.

  1. Geological realism in hydrogeological and geophysical inverse modeling: A review

    NASA Astrophysics Data System (ADS)

    Linde, Niklas; Renard, Philippe; Mukerji, Tapan; Caers, Jef

    2015-12-01

    Scientific curiosity, exploration of georesources and environmental concerns are pushing the geoscientific research community toward subsurface investigations of ever-increasing complexity. This review explores various approaches to formulate and solve inverse problems in ways that effectively integrate geological concepts with geophysical and hydrogeological data. Modern geostatistical simulation algorithms can produce multiple subsurface realizations that are in agreement with conceptual geological models and statistical rock physics can be used to map these realizations into physical properties that are sensed by the geophysical or hydrogeological data. The inverse problem consists of finding one or an ensemble of such subsurface realizations that are in agreement with the data. The most general inversion frameworks are presently often computationally intractable when applied to large-scale problems and it is necessary to better understand the implications of simplifying (1) the conceptual geological model (e.g., using model compression); (2) the physical forward problem (e.g., using proxy models); and (3) the algorithm used to solve the inverse problem (e.g., Markov chain Monte Carlo or local optimization methods) to reach practical and robust solutions given today's computer resources and knowledge. We also highlight the need to not only use geophysical and hydrogeological data for parameter estimation purposes, but also to use them to falsify or corroborate alternative geological scenarios.

  2. 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.

  3. Geological-geophysical techniques applied to urban planning in karst hazardous areas. Case study of Zaragoza, NE Spain

    NASA Astrophysics Data System (ADS)

    Pueyo Anchuela, O.; Soriano, A.; Casas Sainz, A.; Pocoví Juan, A.

    2009-12-01

    Industrial and urban growth must deal in some settings with geological hazards. In the last 50 years, the city of Zaragoza (NE Spain) has developed an increase of its urbanized area in a progression several orders higher than expected from its population increase. This fast growth has affected several areas around the city that were not usually used for construction. Maps of the Zaragoza city area at the end of the XIXth century and beginning of the XXth reveal the presence of karst hazards in several zones that can be observed in more modern data, as aerial photographs taken during a period ranging from 1927 to present. The urban and industrial development has covered many of these hazardous zones, even though potential risks were known. The origins of the karst problems are related to the solution of evaporites (mainly gypsum, glauberite and halite) that represent the Miocene substratum of the Zaragoza area underlying the Quaternary terraces and pediments related to the Ebro River and its tributaries. Historical data show the persistence of subsidence foci during long periods of time while in recent urbanized areas this stability is not shared, observing the increase of activity and/or radius affection in short periods of time after building over. These problems can be related to two factors: i) urban development over hazardous areas can increase the karst activity and ii) the affection radius is not properly established with the commonly applied methods. One way to develop these detailed maps can be related to the geophysical approach. The applied geophysical routine, dependent on the characteristics of the surveyed area, is based on potential geophysical techniques (magnetometry and gravimetry) and others related to the application of induced fields (EM and GPR). The obtained results can be related to more straightforward criteria as the detection of cavities in the subsoil and indirect indicators related to the long-term activity of the subsidence areas

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    Over the last five decades geoscientists from Australian state and federal agencies have collected and assembled around 3 Petabytes of geoscience data sets under public funding. As a consequence of technological progress, data is now being acquired at exponential rates and in higher resolution than ever before. Effective use of these big data sets challenges the storage and computational infrastructure of most organizations. The Virtual Geophysics Laboratory (VGL) is a scientific workflow portal addresses some of the resulting issues by providing Australian geophysicists with access to a Web 2.0 or Rich Internet Application (RIA) based integrated environment that exploits eResearch tools and Cloud computing technology, and promotes collaboration between the user community. VGL simplifies and automates large portions of what were previously manually intensive scientific workflow processes, allowing scientists to focus on the natural science problems, rather than computer science and IT. A number of geophysical processing codes are incorporated to support multiple workflows. For example a gravity inversion can be performed by combining the Escript/Finley codes (from the University of Queensland) with the gravity data registered in VGL. Likewise, tectonic processes can also be modeled by combining the Underworld code (from Monash University) with one of the various 3D models available to VGL. Cloud services provide scalable and cost effective compute resources. VGL is built on top of mature standards-compliant information services, many deployed using the Spatial Information Services Stack (SISS), which provides direct access to geophysical data. A large number of data sets from Geoscience Australia assist users in data discovery. GeoNetwork provides a metadata catalog to store workflow results for future use, discovery and provenance tracking. VGL has been developed in collaboration with the research community using incremental software development practices and open

  5. 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

    Small-scale variations of soil parameters such as water and clay content are of interest in agriculture and soil science. With geophysical methods it is possible to map variations of this scale easily and fast, but the measured geophysical parameters have to be converted into the soil parameters of interest, using geophysical pedotransfer functions (GPTFs). To test the suitability of different GPTFs linking electrical conductivity and permittivity to water content laboratory measurements under controlled conditions have been conducted. 23 large soil samples of different soil types have been taken in the field and dried at room temperature to achieve the lowest possible water content. Each sample was then filled into a plastic cylinder of 75 cm height and 23 cm diameter. This cylinder is equipped with two plate electrodes at bottom and top, respectively, for current injection and two ring electrodes in the middle to measure the potential difference. This array measures the electrical conductivity of the soil sample. To measure the permittivity, a 1.6 GHz GPR antenna was placed on top of the sample and the reflections originating from the bottom plate were recorded. Using the measured traveltime and the known travelpath the velocity and thus the permittivity of the soil could be determined. In successive steps, each sample was progressively saturated with a constant amount of rainwater (2-3 vol%) until full saturation, then measurements of electrical conductivity and permittivity were repeated. The water content was controlled by weighting of added water and the whole sample and small subsamples were taken and dried in the oven to yield the exact water content. Applications of different empirical and constitutive models show that the relatively simple empirical and volumetric mixing models give accurate results in the prediction of the water content from these geophysical parameters. The more complicated effective medium models had only slightly better RMS errors. We

  6. Constrained optimization schemes for geophysical inversion of seismic data

    NASA Astrophysics Data System (ADS)

    Sosa Aguirre, Uram Anibal

    Many experimental techniques in geophysics advance the understanding of Earth processes by estimating and interpreting Earth structure (e.g., velocity and/or density structure). These techniques use different types of geophysical data which can be collected and analyzed separately, sometimes resulting in inconsistent models of the Earth depending on data quality, methods and assumptions made. This dissertation presents two approaches for geophysical inversion of seismic data based on constrained optimization. In one approach we expand a one dimensional (1-D) joint inversion least-squares (LSQ) algorithm by introducing a constrained optimization methodology. Then we use the 1-D inversion results to produce 3-D Earth velocity structure models. In the second approach, we provide a unified constrained optimization framework for solving a 1-D inverse wave propagation problem. In Chapter 2 we present a constrained optimization framework for joint inversion. This framework characterizes 1-D Earth's structure by using seismic shear wave velocities as a model parameter. We create two geophysical synthetic data sets sensitive to shear velocities, namely receiver function and surface wave dispersion. We validate our approach by comparing our numerical results with a traditional unconstrained method, and also we test our approach robustness in the presence of noise. Chapter 3 extends this framework to include an interpolation technique for creating 3-D Earth velocity structure models of the Rio Grande Rift region. Chapter 5 introduces the joint inversion of multiple data sets by adding delay travel times information in a synthetic setup, and leave the posibility to include more data sets. Finally, in Chapter 4 we pose a 1-D inverse full-waveform propagation problem as a PDE-constrained optimization program, where we invert for the material properties in terms of shear wave velocities throughout the physical domain. We facilitate the implementation and comparison of different

  7. Archaeological Geophysics at the San Marcos Pueblo, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Grimes, K.; Joiner, C. J.; Musa, D.; Allred, I.; Delhaye, R. P.; Zorin, N.; Feucht, D. W.; Johnston, G.; Pellerin, L.; McPhee, D.; Ferguson, J. F.

    2013-12-01

    The students and faculty of the Summer of Applied Geophysical Experience (SAGE) geophysical field course have studied the San Marcos Pueblo (LA 98) since 2004. This activity has provided instruction in near-surface geophysics and research into the application of geophysical techniques to southwestern archaeological problems. Our study site, the San Marcos Pueblo, is a classical and colonial period (1200-1680) pueblo that was once one of the largest communities in the southwest. Previous SAGE publications have discussed the discovery of archaeological features, the underlying geology and hydrological conditions. This study focuses on the interpretation of 'El Mapo Grande', 150 m X 150 m, high-resolution (0.5 m) maps of magnetic and electrical properties and 12 seismic refraction lines. The map covers room block, plaza and midden areas as well as areas where colonial period metallurgical activities were known to have occurred. We acquired magnetic, electromagnetic (EM), and ground-penetrating radar (GPR) data in 30 m X 30 m quads producing geophysical maps of each quad (2 or 3 produced each year). Total magnetic field measurements were made with a Geometrics cesium vapor magnetometer, GPR data collected using a Sensors and Software 250 MHz radar were on 0.5 m spaced lines, and EM data were acquired with a Geonics EM-31 on 1 m spaced lines. Seismic data were collected on interconnected lines with 0.5 m receiver and 3 m source interval. El Mapo Grande shows anomalies correlated among the diverse physical properties that were mapped. The edges of strong magnetic anomalies correlate with areas of high GPR scattering possibly associated with rocky floors under room blocks. Areas of high magnetic response are associated with hill-slope erosion channels and plumes of debris in the plaza to the south that are apparently washing down from the metallurgical sites near room blocks. EM data display a good correlation with the magnetic map. Debris channels and plumes are more

  8. Evidence for a critical Earth: the New Geophysics

    NASA Astrophysics Data System (ADS)

    Crampin, Stuart; Gao, Yuan

    2015-04-01

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

  9. Geophysical Characterization and Reactive Transport Modeling to Quantify Plume Behavior

    NASA Astrophysics Data System (ADS)

    Hubbard, S. S.; Wainwright, H.; Bea, S. A.; Spycher, N.; Li, L.; Sassen, D.; Chen, J.

    2012-12-01

    Predictions of subsurface contaminant plume mobility and remediation often fail due to the inability to tractably characterize heterogeneous flow-and-transport properties and monitor critical geochemical transitions over plume-relevant scales. This study presents two recently developed strategies to quantify and predict states and processes across scales that govern plume behavior. Development of both strategies takes advantage of multi-scale and disparate datasets and has involved the use of reactive transport models, geophysical methods, and stochastic integration approaches. The first approach, called reactive facies, exploits coupled physiochemical heterogeneity to characterize subsurface flow and transport properties that impact plume sorption and thus mobility. We develop and test the reactive facies concept within uranium contaminated Atlantic Coastal Plain sediments that underlie the U.S. Department of Energy Savannah River Site, F-Area, South Carolina. Through analysis of field data (core samples, geophysical well logs, and cross-hole ground penetrating radar and seismic datasets) coupled with laboratory sorption studies, we have identified two reactive facies that have unique distributions of mineralogy, texture, porosity, hydraulic conductivity and geophysical attributes. We develop and use facies-based relationships with geophysical data in a Bayesian framework to spatially distribute reactive facies and their associated transport properties and uncertainties along local and plume-scale geophysical transects. To illustrate the value of reactive facies, we used the geophysically-obtained reactive facies properties to parameterize reactive transport models and simulate the migration of an acidic-U(VI) plume through the 2D domains. Modeling results suggest that each identified reactive facies exerts control on plume evolution, highlighting the usefulness of the reactive facies concept and approach for spatially distributing properties that control flow and

  10. 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.

  11. Building 1100--NASA

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Building 1100 is the NASA administrative building. Services located in this building include two banks, a post office, barber shop, cafeteria, snack bar, travel agency, dry cleaners, the NASA Exchange retail store and medical facilities for employees.

  12. BUILDING 341 Seismic Evaluation

    SciTech Connect

    Halle, J.

    2015-06-15

    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3.

  13. Tribal Green Building Toolkit

    EPA Pesticide Factsheets

    This Tribal Green Building Toolkit (Toolkit) is designed to help tribal officials, community members, planners, developers, and architects develop and adopt building codes to support green building practices. Anyone can use this toolkit!

  14. 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

    Hard rock exploration and mining presents many opportunities for the effective use of near surface geophysics. For over 10 years the AfricaArray international geophysics field school has been hosted at a variety of mines in South Africa. While the main objective of the field school is practical training for the next generation of geophysicists, being hosted at a mine has allowed us to investigate applications of near surface geophysics in the early stages of mine planning and development as geophysics is often cheaper and faster than drilling. Several applications include: detailed delineation of dykes and stringer dykes, physical property measurements on drill core for modeling and marker horizons, determination of overburden thickness, locations of water and faults. Dolerite dykes are usually magnetic and are associated with loss of ground (i.e. where the dyke replaces the ore and thus reduces the amount of ore available) and safety/stability concerns. Thus the accurate mapping of dykes and narrow stringers that are associated with them are crucial to the safe planning of a mine. We have acquired several case studies where ground magnetic surveys have greatly improved on the resolution and detail of airborne magnetic surveys in regions of complicated dyke swarms. In many cases, thin stringer dykes of less than 5 cm have been detected. Physical property measurements of these dykes can be used to distinguish between different ages of dykes. It is important to accurately determine overburden thickness when planning an open pit mine as this directly affects the cost of development. Depending on the nature of the overburden, both refraction seismic and or DC resistivity can provide continuous profiling in the area of interest that fills in gaps between boreholes. DC resistivity is also effective for determining water associated with dykes and structures that may affect mine planning. The field school mainly addresses the training of a variety of students. The core

  15. 9. Building 105, Facilities Engineering Building, 1830, interior, Tin Metal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Building 105, Facilities Engineering Building, 1830, interior, Tin Metal area of building, looking S. - Watervliet Arsenal, Building 105, South Broadway, on Hudson River, Watervliet, Albany County, NY

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

    NASA Astrophysics Data System (ADS)

    Eppelbaum, L. V.

    2009-04-01

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

  17. Architecture and evolution of La Réunion inferred from geophysical data

    NASA Astrophysics Data System (ADS)

    Gailler, Lydie; Lénat, Jean-Francois

    2010-05-01

    Architecture and evolution of La Réunion inferred from geophysical data Lydie Gailler and Jean-François Lénat Laboratoire Magmas et Volcans, Université Blaise Pascal, CNRS, Clermont-Ferrand, France The Island of La Réunion, the Indian Ocean, is a large, mostly immerged, oceanic volcanic system. We present a study of its internal structure using geophysical methods. Subaerial and marine gravity and magnetic measurements has been compiled along with terrestrial-based electromagnetic surveys. The ensemble of data has been used to construct gravity, magnetic, and electromagnetic models, which are based on geological constraints and previous geophysical interpretations. We are able to differentiate structures from before and after the Brunhes-Matuyama magnetic inversion using the magnetic measurements according to the polarity of the anomalies. The gravity measurements allow us to detect and characterize the dense intrusive complexes and to complement the magnetic measurements in regard of the nature of the coastal formations and submarine flanks. The electromagnetic surveys allow us to determine the distribution of electrical resistivities which we interpret in terms of saturation of rocks with water, hydrothermal alteration and the presence of mineral hydrates, or complexes of phaneritic or microphaneritics rocks. The integration of the geophysical results allows us to build up a large scale model of the volcanic system. At the scale of the Piton de La Fournaise we distinguish both shallow and deep sources. The shallow ones correspond to the filling of ancient depressions by dense lavas flows, to the Central Cone which is largely constituted of scoria, or to the level of breccias at the base of the large valleys to the south. The deep structures are associated with the intrusive complexes from the Alizés volcano and from the Ancient Shield of the Piton de la Fournaise. The analysis of magnetic anomalies demonstrates a very shallow layer of products from Piton de

  18. Vibration Sources For Geophysical Monitoring of A Medium and Solving of Engineering-geophysical Problems

    NASA Astrophysics Data System (ADS)

    Seleznev, V. S.; Emanov, A. F.; Soloviev, V. M.; Kashun, V. N.; Salnikov, A. S.

    Various vibration sources (powerful stationary, movable and portable) have been de- veloped and are recently used in the Siberian Branch of the Russian Academy of Sciences. These vibrators provide the seismic wave excitation with high stability of radiation. The module design of vibrosources includes the following main elements: the power chamber with a set of centrifugal debalances, the radiating platform and the load, and permits easy to move vibrosources at any necessary distances. The fre- quency of sounding signals varies from a few to 100 Hz. The radiation force changes from 50 kg to 100 tons. The both parameters depend on design of vibrosources. As a result of experimental and methodical studies, carried out in different regions of the Siberia, the monochromatic signals from powerful vibrosources have been recorded in distances to 1500 km, and the high-quality vibroseismic records have been obtained at distances to 350 km. The conducted experimental researches with vibrosources of various design operating in different modes of radiation (sweep and monochromatic signal) at different frequency ranges evidently show an efficiency of application of the powerful stationary, movable and portable vibrosources to vibroseismic studying of earthquake focal zones in seismically active regions, studying the variations of stress- strain condition of a medium, studying of a deep structure as well as at solution of a number of engineering and applied problems, such as: increase of oilfield recovery, detail seismic zoning of territory, investigation of earthquake resistance of buildings and structures.

  19. Tectonic investigation of Central Anatolia, Turkey, using geophysical data

    NASA Astrophysics Data System (ADS)

    Aydemir, Attila

    2009-07-01

    Central Anatolia in Turkey includes a number of internal basins and quite complex geology, but only three major faults can be observed on the surface. There are limited amount of investigations on the tectonic development, structure and history of this area. In this study, tectonic model of the Central Anatolia was investigated using geophysical data and it was compared with recently suggested tectonic models. Existence of two strike-slip faults that have orientations similar to the North Anatolian and East Anatolian Faults in the triple-junction area around the Bingol-Karliova region (eastern Turkey), led some geoscientists to consider the probability of another tectonic escape model in Central Anatolia. Strike-slip characteristics and slip directions of the Sereflikochisar-Aksaray and Ecemis Faults, and the geographical proximity of them are main reasons to consider this model. In this study, the tectonic escape model was investigated and criticized in detail using regional aeromagnetic, gravity, seismic and seismological data. Tectonic developments, faults and their relevance in tectonic setting of the Tuzgolu Basin, together with the comparison of the tectonic escape, and most recent wrench tectonic issues are comprehensively discussed. According to results of this study, existence of tectonic escape between the Sereflikochisar-Aksaray and Ecemis Faults, and geological reasons behind the model are found contradictory requiring geological and geophysical proofs. Moreover, strike direction of the Sereflikochisar-Aksaray Fault is also controversial. Instead of this, a recent model, the regional wrench tectonics appears more reasonable for Central Anatolia that was also supported by the GPS measurements, previous paleomagnetic studies and some recent papers. Geophysical investigation results pointed out that the counter-clockwise rotational movement of the Kirsehir Block to the east of Tuzgolu Basin has been driven by the Kirikkale-Erbaa and Sereflikochisar

  20. Geophysical methods application in groundwater natural protection against pollution

    NASA Astrophysics Data System (ADS)

    Komatina, S. M.

    1994-02-01

    Natural protection against groundwater pollution mostly depends on water-bearing bed coverage with permeable rocks presenting a good or bad pollution intrusion barrier between the surface and subterranean water. Additional positive effects of polluted groundwater self-purification in these zones are visible. Natural protection from surface pollutants primarily depends on natural (geological) factors: (1) presence of poorly permeable rocks; (2) depth, lithology (grain-size distribution), and filtration features of rocks covering groundwater reservoirs; and (3) aquifer depth. In contrast to artesian aquifers, quantitative and qualitative evaluation for natural protection of intergranular aquifers with a free water surface is significantly complicated. In this case, the estimation is possible with the help of a specially developed statistical method, which requires the following elements referring to the zone of aeration: (1) poorly permeable strata depth; (2) filtration features; (3) groundwater level depth; and (4) lithology. For quantitative evaluation, it is necessary to know the time interval for pollution propagating from surface of the terrain to the free water surface. Describe access is particularly useful in the domain of zones of sanitary protection defined around the source of groundwater. This exploration method could be considerably rationalized by geophysical methods application. Various methods are useful, namely: electric mapping and sounding, self-potential method, seismic reflection and refraction methods, gravity and geomagnetic methods, the “turam” method, and different well-logging measurements (gamma ray, gammagamma, radioactivity log, and thermal log). In the paper, geophysical methods applictations in natural protection against groundwater pollution and appropriate critical analysis are presented. The results of this paper are based on the experience and application of geophysical methods to groundwater studies in Yugoslavia by the author.

  1. 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.

  2. Estimating climate resilience for conservation across geophysical settings.

    PubMed

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

    2014-08-01

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

  3. 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.

  4. Time-Lapse Geophysics for Aquifer Characterization and Remediation Monitoring

    NASA Astrophysics Data System (ADS)

    Lane, J. W.

    2003-12-01

    Time-lapse monitoring of subsurface processes is an emerging and promising area of hydrogeophysics. The use of non-invasive or minimally invasive geophysical methods to indirectly measure time-varying fluid saturation, solute concentration, and other hydraulic and geochemical conditions facilitates cost-effective aquifer characterization and remediation. The USGS Office of Ground Water, Branch of Geophysics, in cooperation with USEPA, DOD, and university researchers, has applied time-lapse geophysics for site characterization and remediation monitoring at a number of sites. This talk presents recent examples of applied research, including: (1) application of cross-borehole and surface-to-borehole radar methods to monitor vegetable-oil emulsion injections for biostimulation at a Navy site in Fridley, MN; (2) application of borehole and cross-borehole radar methods to monitor steam injections for remediation of VOCs at the former Loring Air Force Base, ME; (3) application of electrical resistivity tomography to monitor saline tracer tests at the Massachusetts Military Reservation, MA; (4) use of borehole and cross-borehole flowmeter and a discrete-zone packer system to characterize bedrock aquifer hydraulics and water quality at the University of Connecticut landfill, Storrs, CT; and (5) application of crosshole radar methods to monitor a saline tracer in fractured bedrock at the USGS Mirror Lake Site, NH. The goals of these studies are (1) to provide increasingly quantitative information about the subsurface, critical for developing models of aquifer structure, dynamics, and processes, and (2) identification of the spatial and temporal distributions of tracers, contamination, and fluids injected to enhance degradation of contaminants.

  5. Borehole geophysics applied to ground-water investigations

    USGS Publications Warehouse

    Keys, W.S.

    1990-01-01

    The purpose of this manual is to provide hydrologists, geologists, and others who have the necessary background in hydrogeology with the basic information needed to apply the most useful borehole-geophysical-logging techniques to the solution of problems in ground-water hydrology. Geophysical logs can provide information on the construction of wells and on the character of the rocks and fluids penetrated by those wells, as well as on changes in the character of these factors over time. The response of well logs is caused by petrophysical factors, by the quality, temperature, and pressure of interstitial fluids, and by ground-water flow. Qualitative and quantitative analysis of analog records and computer analysis of digitized logs are used to derive geohydrologic information. This information can then be extrapolated vertically within a well and laterally to other wells using logs. The physical principles by which the mechanical and electronic components of a logging system measure properties of rocks, fluids, and wells, as well as the principles of measurement, must be understood if geophysical logs are to be interpreted correctly. Plating a logging operation involves selecting the equipment and the logs most likely to provide the needed information. Information on well construction and geohydrology is needed to guide this selection. Quality control of logs is an important responsibility of both the equipment operator and the log analyst and requires both calibration and well-site standardization of equipment. Logging techniques that are widely used in ground-water hydrology or that have significant potential for application to this field include spontaneous potential, resistance, resistivity, gamma, gamma spectrometry, gamma-gamma, neutron, acoustic velocity, acoustic televiewer, caliper, and fluid temperature, conductivity, and flow. The following topics are discussed for each of these techniques: principles and instrumentation, calibration and standardization

  6. Geophysical constraints on partial melt in the upper mantle

    SciTech Connect

    Shankland, T.J.; O'Connell, R.J.; Waff, H.S.

    1981-08-01

    This paper adresses the conditions under which partial melt can exist in the mantle in order to be observed as a geophysical 'anomaly'. Typical observed anomalies are high electrical conductivity of the order of 0.1 S/m or greater, velocity decreases of 7--10%, seismic Q values less than 100, and a frequency band for seismic effects in the region mear 1 Hz. Existing theories of electrical conduction in partial melts and of frequency-dependent seismic properties together with recent measurements of melt electrical conductivity, viscosity, and partial melt texture can be used to establish requirements for melt to be observed by geophysical methods. From electrical anomalies, mainly sensitive to melt volume and its interconnection, one can require a minimum melt fraction of several percent at temperatures close to the solidus (1150/sup 0/--1300/sup 0/C). However, seismic models demand only a small volume in very flattened shapes (aspect ratio approx. =0.001, melt fraction approx.0.1%). Further, if melt configuration permits seismic dissipation in bulk, that is, there exist flattened voids intersecting more or less equant voids, then it is possible to infer melt fractions for elastic anomalies that are consistent with the several percent required for electrical anomalies. Observed equilibrium textures of partly melted peridotite together with inferred melt-solid surface energies suggest that melt on a grain size scale in a gravitational field segregates into a strongly anisotropic pattern. Thus if partial melt causes mantle geophysical anomalies, it should exist in a variety of void shapes and probably of sizes. While the association of electrical and elastic anomalies with indications of reduced density, volcanism, and high heat flow makes the hypothesis of partial melting an attractive explanation, the minimum physical requirement is for existence of relatively high temperature.

  7. Geophysical techniques for low enthalpy geothermal exploration in New Zealand

    NASA Astrophysics Data System (ADS)

    Soengkono, Supri; Bromley, Chris; Reeves, Robert; Bennie, Stewart; Graham, Duncan

    2013-05-01

    Shallow warm water resources associated with low enthalpy geothermal systems are often difficult to explore using geophysical techniques, mainly because the warm water creates an insufficient physical change from the host rocks to be easily detectable. In addition, often the system also has a limited or narrow size. However, appropriate use of geophysical techniques can still help the exploration and further investigation of low enthalpy geothermal resources. We present case studies on the use of geophysical techniques for shallow warm water explorations over a variety of settings in New Zealand (mostly in the North Island) with variable degrees of success. A simple and direct method for the exploration of warm water systems is shallow temperature measurements. In some New Zealand examples, measurements of near surface temperatures helped to trace the extent of deeper thermal water. The gravity method was utilised as a structural technique for the exploration of some warm water systems in New Zealand. Our case studies show the technique can be useful in identifying basement depths and tracing fault systems associated with the occurrence of hot springs. Direct current (DC) ground resistivity measurements using a variety of electrode arrays have been the most common method for the exploration of low enthalpy geothermal resources in New Zealand. The technique can be used to detect the extent of shallow warm waters that are more electrically conductive than the surrounding cold groundwater. Ground resistivity investigations using the electromagnetic (EM) techniques of audio magnetotellurics (AMT or shallow MT), controlled source audio magnetotellurics (CSAMT) and transient electromagnetic (TEM) methods have also been used. Highly conductive clays of thermal or sedimentary origin often limit the penetration depth of the resistivity techniques and can create some interpretation difficulties. Interpretation of resistivity anomalies needs to be treated in a site specific

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

    NASA Astrophysics Data System (ADS)

    Niederleithinger, E.

    2013-12-01

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

  9. 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).

  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. 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

  12. Analysis of Geophysical Data Bases and Models for Spacecraft Interactions.

    DTIC Science & Technology

    1986-10-31

    electrons, protons, ions (major species), and measured dose. - Evaluation of magnetic field models (Delta B Model). - Quasi- static Data Bases, Analysis ...AIB4 889 ANALYSIS OF GEOPHYSICRL DATA BASES AND MODELS FOR 1/3 SPACECRAFT INTERACTIONS(U) RADEX INC CARLISLE MA J N BAS ET AL 31 OCT 86 AFGL-TR-86...1114 11116 MICROCOPY RESOLUTION TEST CHART NATI()NAL BUREAU flE SIANDARD % 43 A oJ P=I -- % AFGL-TR-86-0221 0 00 ANALYSIS OF GEOPHYSICAL DATA BASES

  13. Combination of Geophysical Methods to Support Urban Geological Mapping

    NASA Astrophysics Data System (ADS)

    Gabàs, A.; Macau, A.; Benjumea, B.; Bellmunt, F.; Figueras, S.; Vilà, M.

    2014-07-01

    Urban geological mapping is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban geological hazards. Geophysics can have a pivotal role to yield subsurface information in urban areas provided that geophysical methods are capable of dealing with challenges related to these scenarios (e.g., low signal-to-noise ratio or special logistical arrangements). With this principal aim, a specific methodology is developed to characterize lithological changes, to image fault zones and to delineate basin geometry in the urban areas. The process uses the combination of passive and active techniques as complementary data: controlled source audio-magnetotelluric method (CSAMT), magnetotelluric method (MT), microtremor H/V analysis and ambient noise array measurements to overcome the limitations of traditional geophysical methodology. This study is focused in Girona and Salt surrounding areas (NE of Spain) where some uncertainties in subsurface knowledge (maps of bedrock depth and the isopach maps of thickness of quaternary sediments) need to be resolved to carry out the 1:5000 urban geological mapping. These parameters can be estimated using this proposed methodology. (1) Acoustic impedance contrast between Neogene sediments and Paleogene or Paleozoic bedrock is detected with microtremor H/V analysis that provides the soil resonance frequency. The minimum value obtained is 0.4 Hz in Salt city, and the maximum value is the 9.5 Hz in Girona city. The result of this first method is a fast scanner of the geometry of basement. (2) Ambient noise array constrains the bedrock depth using the measurements of shear-wave velocity of soft soil. (3) Finally, the electrical resistivity models contribute with a good description of lithological changes and fault imaging. The conductive materials (1-100 Ωm) are associated with Neogene Basin composed by unconsolidated detrital sediments; medium resistive materials (100-400 Ωm) correspond to

  14. Tracking Coherent Structures and Source Localization in Geophysical Flows

    NASA Astrophysics Data System (ADS)

    Forgoston, Eric; Hsieh, Ani; Schwartz, Ira; Yecko, Philip

    There has been a steady increase in the deployment of autonomous underwater and surface vehicles for applications such as ocean monitoring, tracking of marine processes, and forecasting contaminant transport. The underwater environment poses unique challenges since robots must operate in a communication and localization-limited environment where their dynamics are tightly coupled with the environmental dynamics. This work presents current efforts in understanding the impact of geophysical fluid dynamics on underwater vehicle control and autonomy. The focus of the talk is on the use of collaborative vehicles to track Lagrangian coherent structures and to localize contaminant spills. Research supported by the National Science Foundation and the Office of Naval Research.

  15. Lunar science. [geophysics, mineralogy and evolution of moon

    NASA Technical Reports Server (NTRS)

    Brett, R.

    1973-01-01

    A review of the recent developments in lunar science summarizing the most important lunar findings and the known restraints on the theories of lunar evolution is presented. Lunar geophysics is discussed in sections dealing with the figure of the moon, mascons, and the lunar thermal regime; recent seismic studies and magnetic results are reported. The chemical data on materials taken from lunar orbit are analyzed, and the lunar geology is discussed. Special attention is accorded the subject of minerology, reflecting the information obtained from lunar samples of both mare and nonmare origin. A tentative timetable of lunar events is proposed, and the problem of the moon's origin is briefly treated.

  16. Geophysics and nutritional science: toward a novel, unified paradigm.

    PubMed

    Eshel, Gidon; Martin, Pamela A

    2009-05-01

    This article discusses a few basic geophysical processes, which collectively indicate that several nutritionally adverse elements of current Western diets also yield environmentally harmful food consumption patterns. We address oceanic dead zones, which are at the confluence of oceanography, aquatic chemistry, and agronomy and which are a clear environmental problem, and agriculture's effects on the surface heat budget. These exemplify the unknown, complex, and sometimes unexpected large-scale environmental effects of agriculture. We delineate the significant alignment in purpose between nutritional and environmental sciences. We identify red meat, and to a lesser extent the broader animal-based portion of the diet, as having the greatest environmental effect, with clear nutritional parallels.

  17. Geophysical Imaging of Root Architecture and Root-soil Interaction

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Dafflon, B.; Hubbard, S. S.

    2015-12-01

    Roots play a critical role in controlling water and nutrient uptake, soil biogeochemical processes, as well as the physical anchorage for plants. While important processes, such as root hydraulic redistribution for optimal growth and survival have been recognized, representation of roots in climate models, e.g. its carbon storage, carbon resilience, root biomass, and role in regulating water and carbon fluxes across the rhizosphere and atmosphere interface is still challenging. Such a challenge is exacerbated because of the large variations of root architecture and function across species and locations due to both genetic and environmental controls and the lack of methods for quantifying root mass, distribution, dynamics and interaction with soils at field scales. The scale, complexity and the dynamic nature of plant roots call for minimally invasive methods capable of providing quantitative estimation of root architecture, dynamics over time and interactions with the soils. We present a study on root architecture and root-soil interactions using geophysical methods. Parameters and processes of interests include (1) moisture dynamics around root zone and its interaction with plant transpiration and environmental controls and (2) estimation of root structure and properties based on geophysical signals. Both pot and field scale studies were conducted. The pot scale experiments were conducted under controlled conditions and were monitored with cross-well electrical resistivity tomography (ERT), TDR moisture sensors and temperature probes. Pots with and without a tree were compared and the moisture conditions were controlled via a self regulated pumping system. Geophysical monitoring revealed interactions between roots and soils under dynamic soil moisture conditions and the role of roots in regulating the response of the soil system to changes of environmental conditions, e.g. drought and precipitation events. Field scale studies were conducted on natural trees using

  18. Russian Meteorological and Geophysical Rockets of New Generation

    NASA Astrophysics Data System (ADS)

    Yushkov, V.; Gvozdev, Yu.; Lykov, A.; Shershakov, V.; Ivanov, V.; Pozin, A.; Afanasenkov, A.; Savenkov, Yu.; Kuznetsov, V.

    2015-09-01

    To study the process in the middle and upper atmosphere, ionosphere and near-Earth space, as well as to monitor the geophysical environment in Russian Federal Service for Hydrology and Environmental Monitoring (ROSHYDROMET) the development of new generation of meteorological and geophysical rockets has been completed. The modern geophysical research rocket system MR-30 was created in Research and Production Association RPA "Typhoon". The basis of the complex MR-30 is a new geophysical sounding rocket MN-300 with solid propellant, Rocket launch takes place at an angle of 70º to 90º from the launcher, which is a farm with a guide rail type required for imparting initial rotation rocket. The Rocket is spin stabilized with a spin rate between 5 and 7 Hz. Launch weight is 1564 kg, and the mass of the payload of 50 to 150 kg. MR-300 is capable of lifting up to 300 km, while the area of dispersion points for booster falling is an ellipse with parameters 37x 60 km. The payload of the rocket MN-300 consists of two sections: a sealed, located below the instrument compartment, and not sealed, under the fairing. Block of scientific equipment is formed on the platform in a modular layout. This makes it possible to solve a wide range of tasks and conduct research and testing technologies using a unique environment of space, as well as to conduct technological experiments testing and research systems and spacecraft equipment. New Russian rocket system MERA (MEteorological Rocket for Atmospheric Research) belongs to so called "dart" technique that provide lifting of small scientific payload up to altitude 100 km and descending with parachute. It was developed at Central Aerological Observatory jointly with State Unitary Enterprise Instrument Design Bureau. The booster provides a very rapid acceleration to about Mach 5. After the burning phase of the buster the dart is separated and continues ballistic flight for about 2 minutes. The dart carries the instrument payload+ parachute

  19. Preliminary Efforts to Couple TETRAD with Geophysics Models

    SciTech Connect

    Shook, G.M.; Renner, J.L.

    2002-02-19

    The Geothermal Program at the Idaho National Engineering and Environmental Laboratory is enhancing our reservoir simulation capabilities by writing new subroutines with TETRAD that write necessary files for use with SAIC's geophysics models, including DC Resistivity, SP, and microgravity. This is part of long-term efforts to develop reservoir models that take advantage of various observations that are - or can be - made on both existing fields or during exploration efforts. These new routines will be made available to the TETRAD user community in 2002 through the next release of TETRAD 2002.

  20. Preliminary Efforts to Couple TETRAD with Geophysics Models

    SciTech Connect

    Shook, George Michael; Renner, Joel Lawrence; Bloomfield, Kevin Kit

    2002-01-01

    The Geothermal Program at the Idaho National Engineering and Environmental Laboratory is enhancing our reservoir simulation capabilities by writing new subroutines with TETRAD that write necessary files for use with SAIC's geophysics models, including DC Resistivity, SP, and microgravity. This is part of long-term efforts to develop reservoir models that take advantage of various observations that are - or can be - made on both existing fields or during exploration efforts. These new routines will be made available to the TETRAD user community in 2002 through the next release of TETRAD 2002.

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

    SciTech Connect

    Not Available

    1990-06-01

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

  2. Geothermal field's interaction with geophysical fields of another nature

    SciTech Connect

    Novik, Oleg B.; Mikhailovskaya, Irina B.; Repin, Dmitry G.; Yershov, Sergey V.

    1996-01-24

    The energy balance of active lithosphere zones is to a large extent determined by nonstationary interaction of mechanical (elastic and hydrodynamic), thermal, electromagnetic, and gravitational geophysical fields. Seismic disturbances of electromagnetic and temperature fields, repeatedly observed before earthquakes are a striking manifestation of this interaction (Sec. 1). Technological processes of exploitation of hydrothermal deposits are determined by the interaction of hydrodynamical and temperature field (Sec. 2). These “fast” interactions (with the characteristic time scale from seconds to years) take place against the background of “slow” thermomechanical interactions (time scale of Myears), the latter determining the formation of regional geothermal fields (Sec. 3).

  3. At quadrennial geophysics fest, earth scientists think globally

    SciTech Connect

    Kerr, R.A.

    1995-07-28

    This article focuses on two areas of current research interest from the International Union of Geodesy and Geophysics meeting in July 1995. The first is the possible long and unlikely seeming change of connections. Linked are the warm surface of the tropical Pacific Ocean, the atmosphere at the midlatitudes in the Southern Hemisphere and the icy stratosphere over Antarctica where the warming of the sea surface 15 years ago may have set the stage for the Antarctic ozone hole. The second major research research reviewed concerned increases in ultraviolet light. Surface radiation in the DNA-damaging region of the spectrum is increasing by as much as 12% per decade at high latitudes.

  4. 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.

  5. Effects of anthropogenic particles on the chemical and geophysical properties of urban soils, Detroit, Michigan

    NASA Astrophysics Data System (ADS)

    Orlicki, Katharine M.

    There is a great need in many cities for a better quality of urban soil maps. This is due to the increasing interest in repurposing vacant land for urban redevelopment, agriculture, and green infrastructure. Mapping vacant urban land in Detroit can be very difficult because anthropogenic soils were often highly variable and frequently contained demolition debris (such as brick), making it difficult to use a hand auger. This study was undertaken in Detroit, MI to create a more efficient way to map urban soils based on their geophysical and chemical properties. This will make the mapping process faster, less labor intensive, and therefore more cost effective. Optical and chemical criteria for the identification and classification of microartifacts (MAs) were made from a set of reference artifacts of a known origin. These MAs were then observed and tested in urban topsoil samples from sites in Detroit, Michigan that represent three different land use types (residential demolition, fly ash-impacted, and industrial). Optical analyses, SEM, EDAX, and XRD showed that reference MAs may be classified into five basic compositional types (carbonaceous, calcareous, siliceous, ferruginous and miscellaneous). Reference MAs were generally distinguishable using optical microscopy by color, luster, fracture and microtexture. MAs that were more difficult to classify were further differentiable when using SEM, EDAX, and XRD. MAs were found in all of the anthropogenic soils studied, but were highly variable. All three study sites had concentrations coal-related wastes were the most common types of MAs observed and often included coal, ash (microspheres, microagglomerate), cinders, and burnt shale. MAs derived from waste building materials such as brick, mortar, and glass, were typically found on residential demolition sites. Manufacturing waste MAs, which included iron-making slag and coked coal were commonly observed on industrial sites. Fly ash-impacted sites were composed of only

  6. 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

  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. 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.

  9. 78 FR 33859 - Outer Continental Shelf (OCS) Geological and Geophysical Exploration Activities in the Gulf of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... Continental Shelf (OCS) Geological and Geophysical Exploration Activities in the Gulf of Mexico; Correction... in the Federal Register (78 FR 27427) entitled ``Outer Continental Shelf Geological and...

  10. Modular Buildings Buying Guide.

    ERIC Educational Resources Information Center

    Morris, Susan

    1991-01-01

    Suggests that child care program directors who are expanding their programs or opening new child care centers investigate the possibility of renting, leasing, or purchasing a modular building. Discusses the advantages of modular buildings over conventional building construction or rented space in an occupied building. Provides information about…

  11. The Building Commissioning Handbook.

    ERIC Educational Resources Information Center

    Heinz, John A.; Casault, Rick

    This book discusses building commissioning, which is the process of certifying that a new facility meets the required specifications. As buildings have become more complex, the traditional methods for building start-up and final acceptance have been proven inadequate, and building commissioning has been developed, which often necessitates the use…

  12. Geophysical investigation to reveal the groundwater condition at new Borg El-Arab industrial city, Egypt

    NASA Astrophysics Data System (ADS)

    Basheer, Alhussein A.; Mansour, Khamis Q.; Abdalla, Mohammed A.

    2014-12-01

    New Borg El-Arab City, 60 km to the southwest of Alexandria City, is one of new industrial cities planned by the Egyptian Government through its program to transfer the population from the condensed Nile Delta to other places in Egypt. Because such a city includes airport, huge buildings, factories, and worker settlements, a careful geophysical study is planned to reveal the groundwater condition. This will help in defining the places of wells that are supposed to be drilled. Therefore more industrial and agricultural activities will be flourished. The present study embraces Vertical Electrical Soundings (VES'es) and Time Domain Electromagnetic sounding (TEM) to investigate the study area. The study aims to delineate the main subsurface conditions from the viewpoint of groundwater location, depth and water quality. Analysis and interpretation of the obtained results reveal that the subsurface consists of five geoelectrical layers with a gentle general slope toward the Mediterranean Sea. The third and the fourth layers in the succession are suggested to be the two water bearing formations of which the third layer is saturated with fresh water overlying saline water at the bottom of the fourth one. It is worth mentioning that the fresh water depth varies between 50 and 354 m under the ground surface. The thickness of the fresh water aquifer varies from 9.5 to 66 m; and the saline water depth varies between 116 and 384 m below the ground surface, the thickness of saline water aquifer differs from 34 to 90.5 m.

  13. The International Geophysical Month: Short periods of cooperative study can consolidate the gains of the International Geophysical Year.

    PubMed

    Helliwell, R A; Martin, L H

    1961-12-01

    For convenience, we summarize below some of the main advantages of the IGM concept. 1) Most organizations can mount and support intensive field operations for short periods. 2) High-quality data would be obtained, and the data could be processed more promptly than in long-term projects. 3) Laboratory equipment could in many instances be mnade available for field operations. 4) Top-caliber researchers would be available for field operations. 5) The participation of small research groups and of research workers from government and industry would be fostered. 6) Student participation would improve educational programs in, and attract needed talent to, the geophysical sciences. 7) Ship, satellite, and rocket observations could be scheduled for IGM's. 8) International scientific conferences scheduled to follow IGM's would attract working scientists. It is not suggested that these short-term exercises should replace the long synoptic programs characteristic of the IGY. Rather it is proposed that they supplement and guide any such future long-term program. If adopted, they would produce many data of value for the planning and timing of the International Year of the Quiet Sun. To bring emphasis on special observations during the IQSY, International Geophysical Months might well be scheduled to coincide with the June and December solstices, to be followed by an IGM at an equinoctial period. This would provide periods for concentrated sampling-periods in somewhat the same category as the Regular World Intervals adopted during the IGY. The more elaborate experiments could be confined to the International Geophysical Months, so that only those studies for which continuous observations are essential would be scheduled for the entire period. The duration of an International Geophysical Month would be sufficient for carrying out experiments requiring moving platforms such as ships, rockets, or satellites. It is recommended that every effort be made to schedule the first IGM

  14. Space, geophysical research related to Latin America - Part 2

    NASA Astrophysics Data System (ADS)

    Mendoza, Blanca; Shea, M. A.

    2016-11-01

    For the last 25 years, every two to three years the Conferencia Latinoamericana de Geofísica Espacial (COLAGE) is held in one of the Latin American countries for the purpose of promoting scientific exchange among scientists of the region and to encourage continued research that is unique to this area of the world. At the more recent conference, the community realized that many individuals both within and outside Latin America have contributed greatly to the understanding of the space sciences in this area of the world. It was therefore decided to assemble a Special Issue Space and Geophysical Physics related to Latin America, presenting recent results and where submissions would be accepted from the world wide community of scientists involved in research appropriate to Latin America. Because of the large number of submissions, these papers have been printed in two separate issues. The first issue was published in Advances in Space Research, Vol. 57, number 6 and contained 15 papers. This is the second issue and contains 25 additional papers. These papers show the wide variety of research, both theoretical and applied, that is currently being developed or related to space and geophysical sciences in the Sub-Continent.

  15. Premelting, Snowballs and Climate Change: the ice Physics in Geophysics

    NASA Astrophysics Data System (ADS)

    Wettlaufer, J. S.; Rempel, A. W.; Worster, M. G.

    2001-12-01

    A basic question in the theory of surface phase transitions is ``How does a crystalline solid melt?'' Although we can date the scientific study of phase transitions to at least calcolithic times, today we still rely almost exclusively on empirical descriptions of melting phenomena. For practical reasons much of what we know today has been driven by studying the properties of surfaces, but in the process much has been assumed about the behavior of bulk solids. When we pursue the answer to this fundamental question in the context of ice, we find that a microscopic understanding has a plethora of geophysical implications. Recent advances show that the microscopic interfacial structure of ice is central to pattern formation during ice crystal growth, the adhesion of ice, the evolution of the polycrystalline fabrics of the glaciers, and the underlying dynamics of frost heave. Current research focuses on, in part, consequences of microphysics in the scavenging of atmospheric pollutants by snow, the role of stratospheric ice in ozone destruction, the mechanism of charge transfer driving thunderstorm electrification, the effects of frost heave on engineered structures, and natural ice sheets. This talk describes our emerging understanding of the materials physics of ice, its implications for the basic principles of melting, and several of their geophysical consequences.

  16. 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.

  17. Geophysical Techniques for Monitoring CO2 Movement During Sequestration

    SciTech Connect

    Erika Gasperikova; G. Michael Hoversten

    2005-11-15

    The relative merits of the seismic, gravity, and electromagnetic (EM) geophysical techniques are examined as monitoring tools for geologic sequestration of carbon dioxide (CO{sub 2}). This work does not represent an exhaustive study, but rather demonstrates the capabilities of a number of geophysical techniques for two synthetic modeling scenarios. The first scenario represents combined CO{sub 2} enhanced oil recovery (EOR) and sequestration in a producing oil field, the Schrader Bluff field on the north slope of Alaska, USA. EOR/sequestration projects in general and Schrader Bluff in particular represent relatively thin injection intervals with multiple fluid components (oil, hydrocarbon gas, brine, and CO{sub 2}). This model represents the most difficult end member of a complex spectrum of possible sequestration scenarios. The time-lapse performance of seismic, gravity, and EM techniques are considered for the Schrader Bluff model. The second scenario is a gas field that in general resembles conditions of Rio Vista reservoir in the Sacramento Basin of California. Surface gravity, and seismic measurements are considered for this model.

  18. 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.

  19. Environmental geophysics, offshore Bush River Peninsula, Aberdeen Proving Ground, Maryland

    SciTech Connect

    Miller, S.F.; Kuecher, G.J.; Davies, B.E.

    1995-11-01

    Geophysical studies in shallow waters adjacent to the Bush River Peninsula, Edgewood Area of Aberdeen Proving Ground, Maryland, have delineated the extent of waste disposal sites and established a hydrogeologic framework, which may control contaminant transport offshore. These studies indicate that during the Pleistocene Epoch, alternating stands of high and low sea levels resulted in a complex pattern of shallow channel-fill deposits around the Bush River Peninsula. Ground-penetrating radar studies reveal paleochannels greater than 50 ft deep. Some of the paleochannels are also imaged with marine seismic reflection. Conductivity highs measured with the EM-31 are also indicative of paleochannels. This paleochannel depositional system is environmentally significant because it may control the shallow groundwater flow regime beneath the peninsula. Magnetic, conductivity, and side-scan sonar anomalies outline anthropogenic anomalies in the study area. On the basis of geophysical data, underwater anthropogenic materials do exist in some isolated areas, but large-scale offshore dumping has not occurred in the area studied.

  20. 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.

  1. Introductory Geophysics at Colorado College: A Research-Driven Course

    NASA Astrophysics Data System (ADS)

    Bank, C.

    2003-12-01

    Doing research during an undergraduate course provides stimulus for students and instructor. Students learn to appreciate the scientific method and get hands-on experience, while the instructor remains thrilled about teaching her/his discipline. The introductory geophysics course taught at Colorado College is made up of four units (gravity, seismic, resistivity, and magnetic) using available geophysical equipment. Within each unit students learn the physical background of the method, and then tackle a small research project selected by the instructor. Students pose a research question (or formulate a hypothesis), collect near-surface data in the field, process it using personal computers, and analyse it by creating computer models and running simple inversions. Computer work is done using the programming language Matlab, with several pre-coded scripts to make the programming experience more comfortable. Students then interpret the data and answer the question posed at the beginning. The unit ends with students writing a summary report, creating a poster, or presenting their findings orally. First evaluations of the course show that students appreciate the emphasis on field work and applications to real problems, as well as developing and testing their own hypotheses. The main challenge for the instructor is to find feasible projects, given the time constraints of a course and availability of field sites with new questions to answer. My presentation will feature a few projects done by students during the course and will discuss the experience students and I have had with this approach.

  2. 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

  3. Optimizing a direct string magnetic gradiometer for geophysical exploration.

    PubMed

    Sunderland, Andrew; Ju, Li; Blair, David G; McRae, Wayne; Veryaskin, Alexey V

    2009-10-01

    Magnetic gradiometers are tools for geophysical exploration. The magnetic gradient is normally calculated by subtracting the outputs of two total field magnetometers which are separated by a baseline. Here we present a unique device that directly measures magnetic gradients using only a single string as its sensing element. The main advantage of a direct string magnetic gradiometer is that only gradients can induce second harmonic string vibrations. A high common mode rejection ratio is thus naturally achieved without any balancing technique. Performance depends on the ability to dissipate heat while minimizing air damping. By combining high current, an elevated temperature and low pressure, we can easily achieve sensitivity of 0.18 nT/m/square root of Hz. Further increases in sensitivity can be attained by optimizing the sensing element. In this paper we present an in-depth study of the most critical parameters of the magnetic gradiometer. We describe the design for the next generation of sensor, which will reach the required sensitivity of 0.01 nT/m/square root of Hz using only 1 W of power. By combining a few single-axis magnetic gradiometer modules, it will be possible to deploy a full tensor magnetic gradiometer with more than sufficient sensitivity for airborne geophysical applications.

  4. 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.

  5. Preliminary report on geophysical data in Yavapai County, Arizona

    USGS Publications Warehouse

    Langenheim, V.E.; Hoffmann, J.P.; Blasch, K.W.; DeWitt, Ed; Wirt, Laurie

    2002-01-01

    Recently acquired geophysical data provide information on the geologic framework and its effect of groundwater flow and on stream/aquifer interaction in Yavapai County, Arizona. High-resolution aeromagnetic data reflect diverse rock types at and below the topographic surface and have permitted a preliminary interpretation of faults and underlying rock types (in particular, volcanic) that will provide new insights on the geologic framework, critical input to future hydrologic investigations. Aeromagnetic data map the western end of the Bear Wallow Canyon fault into the sedimentary fill of Verde Valley. Regional gravity data indicate potentially significant accumulations of low-density basin fill in Big Chino, Verde, and Williamson Valleys. Electrical and seismic data were also collected and help evaluate the approximate depth and extent of recent alluvium overlying Tertiary and Paleozoic sediments. These data will be used to ascertain the potential contribution of shallow ground-water subflow that cannot be measured by gages or flow meters and whether stream flow in losing reaches is moving as subflow or is being lost to the subsurface. The geophysical data will help produce a more robust groundwater flow model of the region.

  6. Uncertainties in radiometer intercalibration associated with variability in geophysical parameters

    NASA Astrophysics Data System (ADS)

    Yang, John Xun; McKague, Darren S.; Ruf, Christopher S.

    2016-10-01

    Spaceborne radiometry plays a major role in weather and climate science and applications. Intercalibrating different radiometers has become an indispensable task for diagnosing instrument performance and integrating constellation data to extend the observational record. Because intercalibration affects both base radiance data and downstream science products, it is critical to examine intercalibration performance. In this study, we use constellation radiometer data from the Global Precipitation Measurement mission to detect and characterize a pronounced variability in intercalibration stability with a 40 day periodicity. A regional dependence of the calibration is also found. The variability is related to geophysical parameters including water vapor, surface wind speed, and sea surface temperature. It is found that the variability is caused by periodic variations in the local times and locations of the overlap regions between spacecraft. An analytical orbit model is developed for calculating the period of oscillation and agrees well with observation. Calibration errors show nonlinear and nonmonotonic dependences on geophysical parameters and brightness temperature, which cannot be removed by simple linear regression. The variability affects both base radiance calibration accuracy and retrieved science data products.

  7. A pilot study of the dependence of radon concentration on the tectonic structures, using simple geophysical methods.

    PubMed

    Thinova, L; Fronka, A; Rovenska, K

    2011-05-01

    It is well known that there are great variations in radon concentrations in the soil gas on building sites. The concentration may sometimes vary by more than two orders of magnitude. The tectonic structure of the bedrock is one of the factors that influence the intensity of the radon outflow. The simple ARES geophysical method [automatic resistivity system--main unit with standard accessories, multi-electrode cable sections (MCS5)--eight electrodes per 5 m spacing] was used in various modes (Schlumberger, Dipole-Dipole and Pole-Dipole arrays) for in situ tectonic structure determination. The radon concentration in the soil gas was measured using the same network as for the resistivity measurements. The radon measurements were also followed up by in situ gamma spectrometry measurements. The behaviour of the radon concentration in the soil gas was correlated with the detected tectonic non-homogeneities. This pilot study opened up new questions for future analysis.

  8. On turbulent mixing in stably stratified geophysical flows

    NASA Astrophysics Data System (ADS)

    Venayagamoorthy, Karan

    2016-11-01

    The understanding and quantitative prediction of diapycnal (irreversible) mixing of density and momentum in geophysical flows remains an important ongoing challenge. This is not surprising given the complexity introduced into most geophysical flows by factors such as density stratification, complex topography and a host of physical phenomena associated with such flows. However, accurate prediction of the small-scale irreversible mixing induced by turbulent processes is critical for many applications such as the prediction of heat fluxes and global circulation in oceanic flows. From a practical standpoint, a major goal is the inference of turbulent heat and momentum fluxes using indirect measurements in field studies of geophysical flows. This usually involves the need to either measure directly or infer two key quantities namely: (1) the rate of dissipation of turbulent kinetic energy ɛ, and (2) the mixing efficiency Rf*, which is a measure of the amount of turbulent kinetic energy that is irreversibly converted into background potential energy, respectively. Indirect estimates of ɛ in oceanic flows has been traditionally achieved by assuming a linear relationship between the Thorpe (vertical overturn) length scale LT and the Ozmidov scale LO. This approach is particularly attractive since the vertical scales of overturns can be readily obtained using a sorting algorithm from inversions in standard density profiles obtained from Conductivity-Temperature-Depth (CTD) measurements in the ocean. Hence, LT is essentially a kinematic scale that provides a description of the turbulence at a given sampling location. On the other hand, LO is a representative dynamic length scale of the largest eddy that is unaffected by buoyancy. A review of a number of recent studies that were conducted in our research group will be presented in this talk to highlight the lack of a linear relationship between LT and LO. These studies indicate that inferred estimates of ɛ may be biased

  9. 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

  10. Facilitating Scientific Collaboration and Education with Easy Access Web Maps Using the AGAP Antarctic Geophysical Data

    NASA Astrophysics Data System (ADS)

    Abdi, A.

    2012-12-01

    Science and science education benefit from easy access to data yet often geophysical data sets are large, complex and difficult to share. The difficulty in sharing data and imagery easily inhibits both collaboration and the use of real data in educational applications. The dissemination of data products through web maps serves a very efficient and user-friendly method for students, the public and the science community to gain insights and understanding from data. Few research groups provide direct access to their data, let alone map-based visualizations. By building upon current GIS infrastructure with web mapping technologies, like ArcGIS Server, scientific groups, institutions and agencies can enhance the value of their GIS investments. The advantages of web maps to serve data products are many; existing web-mapping technology allows complex GIS analysis to be shared across the Internet, and can be easily scaled from a few users to millions. This poster highlights the features of an interactive web map developed at the Polar Geophysics Group at the Lamont-Doherty Earth Observatory of Columbia University that provides a visual representation of, and access to, data products that resulted from the group's recently concluded AGAP project (http://pgg.ldeo.columbia.edu). The AGAP project collected more than 120,000 line km of new aerogeophysical data using two Twin Otter aircrafts. Data included ice penetrating radar, magnetometer, gravimeter and laser altimeter measurements. The web map is based upon ArcGIS Viewer for Flex, which is a configurable client application built on the ArcGIS API for Flex that works seamlessly with ArcGIS Server 10. The application can serve a variety of raster and vector file formats through the Data Interoperability for Server, which eliminates data sharing barriers across numerous file formats. The ability of the application to serve large datasets is only hindered by the availability of appropriate hardware. ArcGIS is a proprietary

  11. Alaska shorefast ice: Interfacing geophysics with local sea ice knowledge and use

    NASA Astrophysics Data System (ADS)

    Druckenmiller, Matthew L.

    This thesis interfaces geophysical techniques with local and traditional knowledge (LTK) of indigenous ice experts to track and evaluate coastal sea ice conditions over annual and inter-annual timescales. A novel approach is presented for consulting LTK alongside a systematic study of where, when, and how the community of Barrow, Alaska uses the ice cover. The goal of this research is to improve our understanding of and abilities to monitor the processes that govern the state and dynamics of shorefast sea ice in the Chukchi Sea and use of ice by the community. Shorefast ice stability and community strategies for safe hunting provide a framework for data collection and knowledge sharing that reveals how nuanced observations by Inupiat ice experts relate to identifying hazards. In particular, shorefast ice break-out events represent a significant threat to the lives of hunters. Fault tree analysis (FTA) is used to combine local and time-specific observations of ice conditions by both geophysical instruments and local experts, and to evaluate how ice features, atmospheric and oceanic forces, and local to regional processes interact to cause break-out events. Each year, the Barrow community builds trails across shorefast ice for use during the spring whaling season. In collaboration with hunters, a systematic multi-year survey (2007--2011) was performed to map these trails and measure ice thickness along them. Relationships between ice conditions and hunter strategies that guide trail placement and risk assessment are explored. In addition, trail surveys provide a meaningful and consistent approach to monitoring the thickness distribution of shorefast ice, while establishing a baseline for assessing future environmental change and potential impacts to the community. Coastal communities in the region have proven highly adaptive in their ability to safely and successfully hunt from sea ice over the last 30 years as significant changes have been observed in the ice zone

  12. Using ground-based geophysics to rapidly and accurately map sub-surface acidity

    NASA Astrophysics Data System (ADS)

    Wong, Vanessa; Triantafilis, John; Johnston, Scott; Nhan, Terence; Page, Donald; Wege, Richard; Hirst, Phillip; Slavich, Peter

    2013-04-01

    sulfuric and sulfidic layers (oxidised and reduced ASS), acidic shallow groundwater, and features of the infilled palaeovalley (Triantafilis et al. 2012). Accurate soil maps with high spatial resolution are required to develop appropriate management strategies for ASS and other soil types associated with low-lying coastal floodplains. The classes identified in this study form sensible soil management zones across the study area related to defined geomorphic units. EM data can then be used to build below-ground 3D models to inform practical targeted management strategies on coastal floodplains to improve land and water quality outcomes. References Triantafilis J, Wong V, Santos FAM, Page D, Wege R (2012) Modeling the electrical conductivity of hydrogeological strata using joint-inversion of loop-loop electromagnetic data. Geophysics 77(4): WB99-WB107

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

    NASA Astrophysics Data System (ADS)

    De Giorgi, L.; Leucci, G.

    2014-07-01

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

  14. 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

  15. Synchronization in chaotic Hamiltonian systems and a geophysical application.

    PubMed

    Hannachi, A

    1999-07-01

    This paper addresses the question of the rate of synchronization of two identical systems as a function of the inserting time interval Delta t between inserted variables of the driving system in the role of the same variables of the driven system in a simplified Hamiltonian system and its application to a simplified geophysical model. We start by analyzing the synchronization in a simplified two-degree Hamiltonian system. The synchronization rate turns out to be a decreasing function of the inserting time interval Delta t up to a certain limit Delta t(o) where the process reverses and the synchronization rate becomes slower as the inserting frequency decreases. The key point of the analysis uses a second-order Taylor expansion of the system resolvent which indicates that synchronization rate is basically of order O(Delta t(2)) for small Delta t. The study is then extended to include a simplified geophysical system. A nonlinear one-dimensional shallow-water model on a periodic domain meant to represent a latitudinal circle around 45 degrees N is used. It is found that when the zonal wind is inserted, the maximum synchronization rate is obtained when the inserting time interval is approximately 4 h. When the meridional wind is inserted, it is obtained at slightly less than 4 h. It is shown, in particular, that the synchronization rate depends on the latitude (or the Coriolis parameter). A low-order simplified dynamical system derived from the one-dimensional shallow-water model is used to show that this optimum time interval Delta t(o) when the zonal wind and the geopotential, for example, are inserted varies approximately as square root of [2]/2 Omega sin phi to accuracy O(Delta t(3)). Analyses performed with a linear version of the shallow-water model reveal that this latter can be used to explain the observed convergence behavior in the nonlinear model. The only point is the choice of the stationary state for linearization purposes. It is then suggested that in

  16. Deep Interior: The first comprehensive geophysical investigation of an asteroid

    NASA Astrophysics Data System (ADS)

    Asphaug, E.; Belton, M.; Klaasen, K.; McFadden, L.; Ostro, S.; Safaeinili, A.; Scheeres, D.; Sunshine, J.; Yeomans, D.

    Near-Earth Objects (NEOs) come closer to Earth than any other celestial body, and their compositions are represented on Earth by thousands of well-studied meteorites. Yet we understand neither their origin, evolution, nor their geophysical behavior. These secrets are locked up in their unexplored interiors. Goal 1 of the NASA Strategic Plan emphasizes the requirement to catalogue and understand NEOs down to 1 km diameter. Goal 4 urges us to understand natural processes at work in the low gravity environment. Goal 5 expresses the need to explore the solar system and to learn how planets originated and evolved. In response to the NASA Strategic Plan we are proposing a NASA Discovery mission whose primary science objective is to greatly advance the realization of these Goals by conducting the first investigation of the global geophysics of an asteroid. Radio reflection data from 5 km orbit about a 1 km NEO will provide a tomographic 3D image of electromagnetic properties. Mechanical properties will be examined in the simplest possible way, using explosions to initiate seismic cratering events and to expose diverse interior units for spectroscopic analysis. Deep Interior is the lowest-risk, lowest cost path towards attaining the required characterization of NEOs. It breaks new ground for future missions to asteroids and comets and facilitates the design of reliable NEO technologies. Our science goals are as follows, and the techniques (radio science, imaging, IR spectroscopy, active surface science) will be described at this meeting: Asteroid Interiors. Radio, gravity, and seismology experiments give a complete first picture of an asteroid's deep interior, resolving inclusions, voids and unit boundaries at ˜ 30 m scales, and determining global and regional mechanical properties. Surface Geophysics. Blast experiments explore the structure and mechanics of the upper meters, demonstrate microgravity cratering, trigger natural geomorphic events, and expose subsurface

  17. The Emergence of Geophysics in Nineteenth Century Britain.

    NASA Astrophysics Data System (ADS)

    Kushner, David S.

    1990-01-01

    Three central interdisciplinary problems were crucial to the coalescence of a nascent community of scientists in Victorian Britain that was concerned specifically with questions about the nature and history of the earth as a physical body. These were (1) the structure of the earth and the thickness of its crust, (2) the age of the earth, and (3) the astronomical and physical causes of glacial epochs, or ice ages. This thesis concentrates on a particular interdisciplinary approach to these problems that explicitly sought to apply the techniques and methods of mathematical physics to the concerns of geology. The result was a new strand of applied mathematics and physics of the earth that was denominated 'physical geology' or 'terrestrial physics,' and eventually 'geophysics.' The thesis analyzes the mathematical foundations of this new strand and its evolving relationship with the parent disciplines, culminating in the transformation of the new field in the hands of Sir George Darwin, son of Charles, through his own brand of applied mathematics. The central historiographical aim is to analyze the dynamics of controversy and its role in the formation of the new discipline of geophysics. The origins of the field are traced to the researches of William Hopkins (c. 1840) on the phenomenon of precession to determine the thickness of the earth's crust. These are followed through to the 1860s research program of William Thomson (later Lord Kelvin) in terrestrial physics, wherein various concerns were tied together, notably the effective tidal rigidity of the earth and arguments to limit the earth's age, especially on the basis of tidal retardation. George Darwin's mathematical program, sparked by efforts to use polar wandering to explain glacial epochs, elaborated an entire theory of tidal evolution that explained the earth's physical history, including the obliquity of the ecliptic and the fissipartition of the moon. By the mid-1880s Darwin had bound together all three of

  18. REVIEW ARTICLE: Geophysical signatures of oceanic core complexes

    NASA Astrophysics Data System (ADS)

    Blackman, Donna K.; Canales, J. Pablo; Harding, Alistair

    2009-08-01

    Oceanic core complexes (OCCs) provide access to intrusive and ultramafic sections of young lithosphere and their structure and evolution contain clues about how the balance between magmatism and faulting controls the style of rifting that may dominate in a portion of a spreading centre for Myr timescales. Initial models of the development of OCCs depended strongly on insights available from continental core complexes and from seafloor mapping. While these frameworks have been useful in guiding a broader scope of studies and determining the extent of OCC formation along slow spreading ridges, as we summarize herein, results from the past decade highlight the need to reassess the hypothesis that reduced magma supply is a driver of long-lived detachment faulting. The aim of this paper is to review the available geophysical constraints on OCC structure and to look at what aspects of current models are constrained or required by the data. We consider sonar data (morphology and backscatter), gravity, magnetics, borehole geophysics and seismic reflection. Additional emphasis is placed on seismic velocity results (refraction) since this is where deviations from normal crustal accretion should be most readily quantified. However, as with gravity and magnetic studies at OCCs, ambiguities are inherent in seismic interpretation, including within some processing/analysis steps. We briefly discuss some of these issues for each data type. Progress in understanding the shallow structure of OCCs (within ~1 km of the seafloor) is considerable. Firm constraints on deeper structure, particularly characterization of the transition from dominantly mafic rock (and/or altered ultramafic rock) to dominantly fresh mantle peridotite, are not currently in hand. There is limited information on the structure and composition of the conjugate lithosphere accreted to the opposite plate while an OCC forms, commonly on the inside corner of a ridge-offset intersection. These gaps preclude full

  19. 3-D object-oriented image analysis of geophysical data

    NASA Astrophysics Data System (ADS)

    Fadel, I.; Kerle, N.; van der Meijde, M.

    2014-07-01

    Geophysical data are the main source of information about the subsurface. Geophysical techniques are, however, highly non-unique in determining specific physical parameters and boundaries of subsurface objects. To obtain actual physical information, an inversion process is often applied, in which measurements at or above the Earth surface are inverted into a 2- or 3-D subsurface spatial distribution of the physical property. Interpreting these models into structural objects, related to physical processes, requires a priori knowledge and expert analysis which is susceptible to subjective choices and is therefore often non-repeatable. In this research, we implemented a recently introduced object-based approach to interpret the 3-D inversion results of a single geophysical technique using the available a priori information and the physical and geometrical characteristics of the interpreted objects. The introduced methodology is semi-automatic and repeatable, and allows the extraction of subsurface structures using 3-D object-oriented image analysis (3-D OOA) in an objective knowledge-based classification scheme. The approach allows for a semi-objective setting of thresholds that can be tested and, if necessary, changed in a very fast and efficient way. These changes require only changing the thresholds used in a so-called ruleset, which is composed of algorithms that extract objects from a 3-D data cube. The approach is tested on a synthetic model, which is based on a priori knowledge on objects present in the study area (Tanzania). Object characteristics and thresholds were well defined in a 3-D histogram of velocity versus depth, and objects were fully retrieved. The real model results showed how 3-D OOA can deal with realistic 3-D subsurface conditions in which the boundaries become fuzzy, the object extensions become unclear and the model characteristics vary with depth due to the different physical conditions. As expected, the 3-D histogram of the real data was

  20. EVALUATION OF GEOPHYSICAL METHODS FOR THE DETECTION OF SUBSURFACE TETRACHLOROETHYLENE IN CONTROLLED SPILL EXPERIMENTS

    EPA Science Inventory

    The purpose of the work was to determine the capability of various geophysical methods to detect PCE in the subsurface. Measurements were made with ten different geophysical techniques before, during, and after the PCE injection. This approach provided a clear identification of a...