WorldWideScience

Sample records for geophysical prospecting

  1. Airborne geophysical prospecting for ultramafite associated talc, Altermark, northern Norway

    Science.gov (United States)

    Karlsen, Tor Arne; Olesen, Odleiv

    1996-10-01

    Talc-rich rocks in Altermark occur as rims around magnetite bearing serpentinite lenses which are up to about 1 km wide. The content of magnetite in the serpentinite makes magnetic measurements possible as a method for talc-prospecting. In 1991 a helicopter-borne geophysical survey combined with geological and petrophysical mapping was carried out in the Altermark area. Several positive magnetic anomalies were detected. Positive magnetic anomalies with oval shapes, well defined boundaries and smooth anomaly curves were interpreted to be caused by serpentinite lenses. Laboratory measurements revealed susceptibilities for the serpentinites between 0.006-0.36 SI and a Q-value of approximately 0.3. Magnetic modelling of the Nakkan anomaly and subsequent drilling revealed that it was indeed a serpentinite body surrounded by talc rocks which was the cause of the anomaly. The shallowest part was located about 150 m below surface. The geophysical exploration led to the discovery of a talc-carbonate deposit with an anticipated in situ tonnage of more than 1 million tons. The present study consequently proved to be a classical case study where we were able to locate and establish the three-dimensional form of serpentinite bodies associated with talc deposits. We conclude that helicopter-borne geophysical surveying is an effective tool in the exploration of serpentinite cored talc bearing rocks in complex geological areas where exposures are poor or absent and accessibility difficult. The rough topography and dense vegetation in the Altermark area make this type of survey very cost effective.

  2. Development of methods of ore geophysics and a solution to the problems of geological prospecting

    Energy Technology Data Exchange (ETDEWEB)

    Badalian, S.V.; Gamoian, V.B.; Gazarian, G.O.; Gevorkian, M.G.; Gevorkian, V.M.; Kazarian, S.S.; Ovsepian, R.V.

    1981-01-01

    The development of scientific research in the field of ore geophysics along the stages conducted at the academy of Sciences of the Armenian SSR between 1961 and 1980 is given. A short description of separate scientific developments (theoretical methodological and equipment) and results from introducing geophysical methods into geological prospecting procedures in the Armenian SSR are given.

  3. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20152233 An Zhenchang(Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China);Peng Fenglin Inspection and Study on the Geomagnetic Survey,Charts and Models during 1683~1949in China(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,57(11),2014,p.3795-3803,60refs.)

  4. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20080091 Cheng Luying(Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuhan 430077,China);Xu Houze Rotation of the Gravity Potential on the Earth’s Gravity Field Recovery(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,49(1),2006,p.93-98,3 illus.,24 refs.,with English abstract)

  5. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111476 Chen Bin(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China);Gu Zuowen Study of Geomagnetic Secular Variation in China(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,53(9),2010,p.2144-2154,6 illus.,4 tables,38 refs.)Key words:secular variations of geomagnetic field,China

  6. Geophysics

    CERN Document Server

    Bolt, Bruce

    1973-01-01

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

  7. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150056 Gao Yanguang(School of Earth and Space Sciences,Peking University,Beijing 100087,China);Li Yonghua Crustal Thickness and Vp/Vsin the Northeast China-North China Region and Its Geological Implication(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,57(3),2014,p.847-857,7illus.,58 refs.,with English abstract)Key words:crust,Poisson’s ration,Northeast China,North China20150057 He Lijuan(State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sci-

  8. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>20122208 Chen Shi ( Institute of Geophysics,China Earthquake Administration,Beijing 100081,China );Wang Qianshen Thermal Isostasy of North China and Its Gravity Isostasy and Deep Structure ( Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074 / P,54 ( 11 ), 2011,p.2864-2875,8illus.,1 table,37refs. ) Key words:gravity field,Bouguer anomaly,isostasy theory,North China In this paper,based on the up to date global free-air gravity anomaly dataset ( TopexV18.1 ),

  9. Development of Geophysical Prospecting for Oil Onland in China

    Institute of Scientific and Technical Information of China (English)

    Lu Banggan

    1994-01-01

    @@ China is Developing Geopysical Market CNPC, as a state petroleum corporation onland oil industry,owns 260 seismic crews and 24non-seismic geophysical and geochemical crews. About one third of the seismic crews use 240 and more channel recorders,imported and home-made.

  10. Geophysics

    Science.gov (United States)

    Carr, M. H.; Cassen, P.

    1976-01-01

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

  11. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140634 Cao Lingmin(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China);Xu Yi Finite Difference Tomography of the Crustal Velocity Structure in Tengchong,Yunnan Province(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,56(4),2013,p.1159-1167,6illus.,35refs.,with English abstract)

  12. Mine hydrogeologic conditions prospected by comprehensive geophysical exploration

    Energy Technology Data Exchange (ETDEWEB)

    Xing, X.; Pu, C. [Feicheng Coal Mining Bureau (China)

    1997-12-01

    Mine water gushing is one of the difficult problems puzzling mine safety. The investigation of the hydrogeological condition of the working face is a prerequisite to control effectively the water hazard and guarantee safe mining. The production practice in Feicheng Mining Bureau proved that the comprehensive geophysical survey in which the DC electrical survey, Rayleigh wave method and transient electromagnetic method are the main means, is a simple, high-speed and effective tool to detect the geological structure, water abundance of aquifer and concealed water flowing structure at the working face and the front of driving end. 1 ref., 3 figs.

  13. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091452 Cai Xuelin(School of Earth Science,Chengdu University of Technology,Chengdu 610059,China);Cao Jiaming Lithospheric and Asthenospheric Structures of the Koktokay of Xinjiang to Jianyang of Sichuan Geoscience Transect(Geology in China,ISSN1000-3657,CN11-1167/P,35(3),2008,p.375-391,8 illus.,2 tables,64 refs.)Key words:lithosphere,asthenosphere,Xinjiang,SichuanBy using the theory and method of modern structural analysis,this paper analyzes the explosion seismic sounding profiling and natural seismic surface wave tomographic imaging in the Koktokay of Xinjiang to Jianyang of Sichuan geoscience transect and integrates the results of research on geology,geochemistry,structural petrology of deep-seated xenoliths and geophysical signs.The studies indicate that the geometric structure pattern of high-speed blocks or mantle block tectonics is one of the basic conditions for controlling the lithospheric tectonic pattern and tectonic deformation of the lithospheric surface.

  14. Application of the Earth's Natural Electromagnetic Noise to Geophysical Prospecting and Seraching for Oil

    CERN Document Server

    Malyshkov, Sergey Yu; Gordeev, Vasily F; Shtalin, Sergey G; Polivach, Vitaly I; Bazhanov, Yury Yu; Hauan, Terje

    2011-01-01

    When applying the Earth's natural pulse electromagnetic fields to geophysical prospecting one should take into account characteristics of their spatial and temporal variations. ENPEMF is known to include both pulses attributed to atmospheric thunderstorms and pulses generated in the lithosphere by mechanic-to-electric energy conversion in rocks. It is evident that the most valuable information on the geophysical structure of a certain area is obviously contained in pulses originated from this area. This article covers a method of recording spatial variations of the Earth's natural pulse electromagnetic fields which is able to take due account of spatial and temporal variations of EM fields and suits to reveal crustal structural and lithologic heterogeneities including hydrocarbon pools. We use a system of several stations recording the ENPEMF concurrently to erase the temporal variations from ENPEMF records and to sort out the pulses of local and remote origin. Some stations are fixed (reference) and record o...

  15. Geotechnology for groundwater and salinisation soil using geophysical prospecting; Butsuri tansa wo mochiita chikasui enrui dojo no tansa gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, A. [Sumitomo Metal Industries, Ltd., Osaka (Japan); Imaizumi, M.; Takeuchi, M. [National Research Institute of Agricultural Engineering, Tsukuba (Japan)

    1997-12-01

    This paper takes a general view of geophysical prospecting on groundwater and salinisation soil. It also explains the following examples of prospecting: an example of pursuing movement of saline water lump charged with a tracer by using a specific resistance monitor, as a monitoring survey being a representative example of `visualization of movement` expected as a direction to which physical prospecting should proceed in the future, an example of elucidating distribution of soil salts vertically and two-dimensionally by using the electromagnetic exploration method, and an example of surveying distribution of three-dimensional water permeation coefficients by utilizing geophysical prospecting systems, as an example of estimating property values from geophysical prospecting. Electrical prospecting has been used as an exploration method related to groundwater, whereas its method has been increasing the diversity, such as from vertical exploration to high-density horizontal exploration and tomography. Noticeable progress can also be seen in electromagnetic exploration and logging techniques. In addition, what is demanded in application of physical prospecting to groundwater field may include visualization of ground water flow, more precise estimation of hydraulic constants, and complement of their distribution. 22 refs., 21 figs., 3 tabs.

  16. Prospecting for natural attenuation: Coupled geophysical-biogeochemical studies at DOE's Rifle IFRC site

    Science.gov (United States)

    Williams, K. H.; Kukkadapu, R. K.; Long, P. E.; Flores Orozco, A.; Kemna, A.

    2011-12-01

    compounds and molecular hydrogen, the oxidation of which may be coupled to the reductive immobilization of aqueous uranium by a variety of indigenous microorganism (e.g. Geobacter sp.). The ability to utilize geophysical techniques to assess a site's prospects for natural attenuation thus constitutes an exciting new development in the emerging field of biogeophysics.

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

    Science.gov (United States)

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

    2015-06-01

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

  18. Geology, alteration, mineralization, petrogenesis, geochronology, geochemistry and airborne geophysics of Kuh Shah prospecting area, SW Birjand

    Directory of Open Access Journals (Sweden)

    Maryam Abdi

    2012-04-01

    Full Text Available The Kuh Shah prospecting area is located in Tertiary volcano-plutonic belt of the Lut Block. More than seventeen subvolcanic intermediate to acidic intrusive rocks, diorite to syenite in composition, were identified in the study area. The intrusions are related to hydrothermal alteration zones and contain argillic, propylitic, advanced argillic, silicified, quartz-sericite-pyrite, gossan and hydrothermal breccia which overprinted to each other and are accompanied by weathering which made it complicated to distinguish zoning. Mineralization is observed as sulfide (pyrite and rare chalcopyrite, disseminated Fe-oxides and quartz-Fe-oxide stockwork veinlets. Intrusive rocks are metaluminous, calc-alkaline with shoshonitic affinity with high values of magnetic susceptibility. The Kuh Shah intrusive rocks are classified as magnetite-series of oxidant I-type granitoids. Based on zircon U–Pb age dating, the age of these granitoid rocks is 39.7± 0.7 Ma (Middle Eocene. The radioisotope data (initial 87Sr/86Sr and 143Nd/144Nd ratios as well as εNd and geochemical data suggest that the Kuh Shah granitoid rocks formed from depleted mantle in a subduction-related magmatic arc setting. Geochemical anomalies of elements such as Cu, Au, Fe, Pb, Zn, As, Sb, Mo, Bi, Hg and also Mn, Ba, Te and Se, correlated with quartz-sericite-pyrite, gossan-stockwork-hydrothermal breccias, irregular silicified bodies and advanced argillic hydrothermal alteration zones. Geophysical anomalies correlated with hydrothermal alteration and mineralization zones. The interpretation of the results represents complex patterns of sub-circular to ellipsoid shape with north-east to south-west direction. These evidences are similar to the other for known Cu-Au porphyry and Au-epithermal systems in Iran and worldwide.

  19. Geophysical Prospection of Archaeological Structures in a Noisy Area in Shayzar, Syria

    Science.gov (United States)

    Seren, S.; Hinterleitner, A.; Löcker, K.; Bayirli, E.

    2009-04-01

    Site The roman town "Caesarea", which was named "Sezer" and used as a citadel in middle ages, is located within the modern town "Shayzar" in the north-west of Syria. The modern buildings, power lines and the streets with a lot of cars cause a very noisy environment for geophysical prospection. A football ground of about 50x90 m was chosen for testing both methods, magnetic and ground penetrating radar (GPR), to detect archaeological structures. Instruments and survey area The magnetic survey was carried out using a fluxgate magnetic acquisition system with 4 sensors in gradient array from the manufacturer FÖRSTER® mounted on a one wheel cart. The cart was developed in our institute and allows to record high quality data in areas with difficult field conditions. An optical distance measurement system on the wheel ensures an exact positioning of the magnetic data. The measurement grid was 50x10 cm. GPR survey was carried out using a NOGGIN system with 250 MHz antenna from the manufacturer Sensors & Software. A new base plate was mounted on the antenna for the easy moving at rough surface conditions. The measurement grid was 50x5 cm. Data processing The magnetic data are processed using the self developed software ApMag. The main steps of the processing are filtering, removing of the line pattern, interpolation to a grid of 10x10 cm, geo-referencing and producing of a grey scale magnetogramm for visualizing in a geographical information system (GIS). The GPR data are automatically processed using the self developed software package ApRadar. Several pre-processing steps were carried out including removing of constant shifts, automatic detection of the starting point (time zero), frequency dependent high-pass filtering and a background removal filter to get the best results for each measurement. There is no gain control algorithm applied to the traces of a section but a statistical correction of each depth-slice for each section. This is equal to an automatic gain

  20. Historical overview of geophysical exploration for hydrocarbon prospecting in Japan; Nippon no sekiyu kogyo ni okeru butsuri tanko gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Y. [Japan Petroleum Exploration Corp., Tokyo (Japan)

    1998-08-01

    This paper describes a historical overview of geophysical exploration for hydrocarbon prospecting in Japan. In general, history is divided into eras by the qualitative change. In the case of geophysical exploration, the history is desired to be divided by considering the both of qualitative change in the technology and that in the practical application. In the early time of geophysical prospecting, gravitational exploration, magnetic exploration, seismic refraction method and seismic reflection method were elementarily and successfully tried. In the era of classical geophysical exploration, seismic reflection method and gravitational/magnetic methods were basically completed, and accumulation structures of potential petroleum were discovered around existing oil fields. In the era of systematic geophysical exploration, techniques of underground geological reflection profiles were completed with digitalization, and systematic petroleum exploration was conducted. In the era of modern geophysical exploration, 3D seismic was put into practice, and the inversion accuracy was improved, in which the geophysical exploration could be contributed jointly with the geological techniques. New development era of geophysics is expected. 31 refs., 10 figs., 5 tabs.

  1. A multidisciplinary geophysical investigation of a prospective post-glacial fault in central Sweden

    Science.gov (United States)

    Malehmir, Alireza; Andersson, Magnus; Maries, Georgiana; Mehta, Suman; Munier, Raymond; Place, Joachim; Brodic, Bojan; Smith, Colby; Mikko, Henrik

    2015-04-01

    Glacially induced, intraplate faults are conspicuous in northern Fennoscandia where they reach trace lengths of up to 150 km with estimated magnitudes of 8 and above (e.g. Lagerbäck and Sundh 2008). Based on a nationwide LiDAR survey (Petersen and Rost 2011), recent studies suggest that glacially induced faults are not, as previously understood, confined to the northernmost parts of Sweden and can also be found in the central parts (Smith et al., 2014). Some of these faults are associated with scarps (and possibly landslides) that strike for more than 5 km giving a recognizable expression on LiDAR data. While LiDAR data provide valuable information, it is important that the presence of the fault is ground truthed, its extent and geometry at depth are unraveled and if possible an estimate on its displacement is given. These together with the surface expression represented by the scarp can then provide some information about their displacement mechanism(s) and earthquake magnitude. In this study, we focused on a recently inferred (Smith et al., 2014), through LiDAR data, post/end-glacial fault near the city of Bollnäs about 250 km north of Stockholm. The prospective fault has about 6 km long scarp expression that is ca. 5 m higher in the western side of the scarp. A multidisciplinary geophysical investigation was conducted during October 2014 to provide information about the fault geometry with respect to the scarp, and displacement in the bedrock. This included high-resolution three-component refraction and reflection seismics, gravity and magnetic measurements, ground penetrating radar, radio-magnetotellurics and direct current geoelectrics. Preliminary results suggest a zone of low-velocity and conductivity that is associated with a magnetic lineament that is horizontally about 50 m offset from the scarp. Depth to bedrock surface is about 10 m (consistent in all the measurements) in the eastern side of the scarp while it is about 20 m in the western side. This

  2. Large-scale high-resolution non-invasive geophysical archaeological prospection for the investigation of entire archaeological landscapes

    Science.gov (United States)

    Trinks, Immo; Neubauer, Wolfgang; Hinterleitner, Alois; Kucera, Matthias; Löcker, Klaus; Nau, Erich; Wallner, Mario; Gabler, Manuel; Zitz, Thomas

    2014-05-01

    Over the past three years the 2010 in Vienna founded Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology (http://archpro.lbg.ac.at), in collaboration with its ten European partner organizations, has made considerable progress in the development and application of near-surface geophysical survey technology and methodology mapping square kilometres rather than hectares in unprecedented spatial resolution. The use of multiple novel motorized multichannel GPR and magnetometer systems (both Förster/Fluxgate and Cesium type) in combination with advanced and centimetre precise positioning systems (robotic totalstations and Realtime Kinematic GPS) permitting efficient navigation in open fields have resulted in comprehensive blanket coverage archaeological prospection surveys of important cultural heritage sites, such as the landscape surrounding Stonehenge in the framework of the Stonehenge Hidden Landscape Project, the mapping of the World Cultural Heritage site Birka-Hovgården in Sweden, or the detailed investigation of the Roman urban landscape of Carnuntum near Vienna. Efficient state-of-the-art archaeological prospection survey solutions require adequate fieldwork methodologies and appropriate data processing tools for timely quality control of the data in the field and large-scale data visualisations after arrival back in the office. The processed and optimized visualisations of the geophysical measurement data provide the basis for subsequent archaeological interpretation. Integration of the high-resolution geophysical prospection data with remote sensing data acquired through aerial photography, airborne laser- and hyperspectral-scanning, terrestrial laser-scanning or detailed digital terrain models derived through photogrammetric methods permits improved understanding and spatial analysis as well as the preparation of comprehensible presentations for the stakeholders (scientific community, cultural heritage managers, public). Of

  3. Geophysical prospection of the Roman city of Pollentia, Alcúdia (Mallorca, Balearic Islands, Spain)

    Science.gov (United States)

    Ranieri, G.; Godio, A.; Loddo, F.; Stocco, S.; Casas, A.; Capizzi, P.; Messina, P.; Orfila, M.; Cau, M. A.; Chávez, Mª. E.

    2016-11-01

    We present the results of the geophysical investigation carried out in the Roman city of Pollentia, in the island of Mallorca. The ancient city was identified in the 19th century. Old and new archaeological excavations have helped to uncover a residential area, a theatre, the forum, several necropolises and other remains of the city, but a large unexplored area has still to be investigated. For instance, the limits of the ancient town and the presence of harbour structures are still unknown. The geophysical survey has covered an area of more than 20.000 m2 by integrating magnetic, electromagnetic, electrical and ground penetrating radar (GPR) methods. Many unseen archaeological features were clearly revealed by the interpretation of the resistivity maps and GPR time slices. A new method for the visualisation of the geophysical evidence based on VRML (Virtual Reality Markup Language) 3D data representation provides promising results to drive future excavations. The VRML shows a great potentiality for the digital visualization of the site aimed at its exploitation and usability even without the archaeological excavation.

  4. Application of high resolution geophysical prospecting to assess the risk related to subsurface deformation in Mexico City

    Science.gov (United States)

    Centeno-Salas, F. A.; Carreón-Freyre, D.; Flores-García, W. A.; Gutiérrez-Calderón, R. I.

    2015-11-01

    In the eastern sector of Mexico City the sub soil consists of high contrasting sequences (lacustrine and volcanic inter bedded deposits) that favor the development of erratic fracturing in the surface causing damage to the urban infrastructure. The high-resolution geophysical prospecting are useful tools for the assessment of ground deformation and fracturing associated with land subsidence phenomena. The GPR method allowed to evaluate the fracture propagation and deformation of vulcano-sedimentary sequences at different depths, the main electrical parameters are directly related with the gravimetric and volumetric water content and therefore with the plasticity of the near surface prospected sequences. The active seismology prospection consisted in a combination of Seismic Refraction (SR) and Multichannel Analysis of Surface Waves (MASW) for the estimation of the velocity of the mechanical compressive (P) and the shear (S) waves. The integration of both methods allowed to estimate the geomechanical parameters characterizing the studied sequence, the Poisson Ratio and the volumetric compressibility. The obtained mechanical parameters were correlated with laboratory measured parameters such as plasticity index, density, shear strength and compressibility and, GPR and seismic profiles were correlated with the mapped fracture systems in the study area. Once calibrated, the profiles allowed to identify the lithological contact between lacustrine and volcanic sequences, their variations of thicknesses in depth and to assess the deformation area in the surface. An accurate determination of the geometry of fracturing was of the most importance for the assessment of the geological risk in the study area.

  5. Multi-objective evolutionary optimization for constructing neural networks for virtual reality visual data mining: application to geophysical prospecting.

    Science.gov (United States)

    Valdés, Julio J; Barton, Alan J

    2007-05-01

    A method for the construction of virtual reality spaces for visual data mining using multi-objective optimization with genetic algorithms on nonlinear discriminant (NDA) neural networks is presented. Two neural network layers (the output and the last hidden) are used for the construction of simultaneous solutions for: (i) a supervised classification of data patterns and (ii) an unsupervised similarity structure preservation between the original data matrix and its image in the new space. A set of spaces are constructed from selected solutions along the Pareto front. This strategy represents a conceptual improvement over spaces computed by single-objective optimization. In addition, genetic programming (in particular gene expression programming) is used for finding analytic representations of the complex mappings generating the spaces (a composition of NDA and orthogonal principal components). The presented approach is domain independent and is illustrated via application to the geophysical prospecting of caves.

  6. 探析城市水文地质调查中物探的应用%Application of Geophysical Prospecting in Urban Hydrogeology Investigation

    Institute of Scientific and Technical Information of China (English)

    李雄; 徐世光; 黄建国

    2014-01-01

    Engineering geophysical prospecting techniques show a strong superiority in effectively detecting the geological disasters and accurately determining the hydrogeological parameters, but the ever-changing geological conditions raise new challenges for geophysical prospecting. Various geophysical prospecting methods have strong advantage, but still have some inevitable limitations. The author will briefly describe the application of geophysical prospecting in geological disasters and groundwater exploration.%在有效对地质灾害情况加以检测以及对水文地质参数加以精准的测定方面,工程物探技术显示出强大的优越性,但是地质条件的千变万化对于物探也提出了新的挑战,各种物探方法虽然有着强大的优越性,但是仍不可避免的带有某些局限性。以下,笔者简要就物探在地质灾害以及地下水的勘探等方面的应用加以简要介绍。

  7. Geophysical prospecting for the deep geothermal structure of the Zhangzhou basin, Southeast China

    Science.gov (United States)

    Wu, Chaofeng; Liu, Shuang; Hu, Xiangyun; Wang, Guiling; Lin, Wenjing

    2017-04-01

    Zhangzhou basin located at the Southeast margins of Asian plate is one of the largest geothermal fields in Fujian province, Southeast China. High-temperature natural springs and granite rocks are widely distributed in this region and the causes of geothermal are speculated to be involved the large number of magmatic activities from Jurassic to Cretaceous periods. To investigate the deep structure of Zhangzhou basin, magnetotelluric and gravity measurements were carried out and the joint inversion of magnetotelluric and gravity data delineated the faults and the granites distributions. The inversion results also indicated the backgrounds of heat reservoirs, heat fluid paths and whole geothermal system of the Zhangzhou basin. Combining with the surface geological investigation, the geophysical inversion results revealed that the faults activities and magma intrusions are the main reasons for the formation of geothermal resources of the Zhangzhou basin. Upwelling mantle provides enormous heats to the lower crust leading to metamorphic rocks to be partially melt generating voluminous magmas. Then the magmas migration and thermal convection along the faults warm up the upper crust. So finally, the cap rocks, basements and major faults are the three favorable conditions for the formation of geothermal fields of the Zhangzhou basin.

  8. Integrated Geophysical Study of Lake Bogoria Basin, Kenya: Implications for Geothermal Energy Prospecting

    OpenAIRE

    Mulwa, J.; Barongo, J.; Fairhead, D; Mariita, N.; Patel, J.

    2010-01-01

    The Lake Bogoria basin, here in referred to as the study area, is located in the greater Baringo-Bogoria basin (BBB), about 100 km to the north of Menengai geothermal prospect on the floor of Kenya Rift Valley (KRV). It is bound by latitudes 0~;00’ and 0~'30’N and longitudes 35~'45’E and 36~'15’E within the rift graben. The study area is characterized by geothermal surface manifestations which include hot springs, spouting geysers, fumaroles/steam jets and mud pools. The area is overlain by M...

  9. Mapping of groundwater prospective zones integrating remote sensing, geographic information systems and geophysical techniques in El-Qaà Plain area, Egypt

    Science.gov (United States)

    Abuzied, Sara M.; Alrefaee, Hamed A.

    2017-05-01

    The geospatial mapping of groundwater prospective zones is essential to support the needs of local inhabitants and agricultural activities in arid regions such as El-Qaà area, Sinai Peninsula, Egypt. The study aims to locate new wells that can serve to cope with water scarcity. The integration of remote sensing, geographic information systems (GIS) and geophysical techniques is a breakthrough for groundwater prospecting. Based on these techniques, several factors contributing to groundwater potential in El-Qaà Plain were determined. Geophysical data were supported by information derived from a digital elevation model, and from geologic, geomorphologic and hydrologic data, to reveal the promising sites. All the spatial data that represent the contributing factors were integrated and analyzed in a GIS framework to develop a groundwater prospective model. An appropriate weightage was specified to each factor based on its relative contribution towards groundwater potential, and the resulting map delineates the study area into five classes, from very poor to very good potential. The very good potential zones are located in the Quaternary deposits, with flat to gentle topography, dense lineaments and structurally controlled drainage channels. The groundwater potential map was tested against the distribution of groundwater wells and cultivated land. The integrated methodology provides a powerful tool to design a suitable groundwater management plan in arid regions.

  10. Investigating the Surface and Subsurface in Karstic Regions – Terrestrial Laser Scanning versus Low-Altitude Airborne Imaging and the Combination with Geophysical Prospecting

    Directory of Open Access Journals (Sweden)

    Nora Tilly

    2017-08-01

    Full Text Available Combining measurements of the surface and subsurface is a promising approach to understand the origin and current changes of karstic forms since subterraneous processes are often the initial driving force. A karst depression in south-west Germany was investigated in a comprehensive campaign with remote sensing and geophysical prospecting. This contribution has two objectives: firstly, comparing terrestrial laser scanning (TLS and low-altitude airborne imaging from an unmanned aerial vehicle (UAV regarding their performance in capturing the surface. Secondly, establishing a suitable way of combining this 3D surface data with data from the subsurface, derived by geophysical prospecting. Both remote sensing approaches performed satisfying and the established digital elevation models (DEMs differ only slightly. These minor discrepancies result essentially from the different viewing geometries and post-processing concepts, for example whether the vegetation was removed or not. Validation analyses against high-accurate DGPS-derived point data sets revealed slightly better results for the DEMTLS with a mean absolute difference of 0.03 m to 0.05 m and a standard deviation of 0.03 m to 0.07 m (DEMUAV: mean absolute difference: 0.11 m to 0.13 m; standard deviation: 0.09 m to 0.11 m. The 3D surface data and 2D image of the vertical cross section through the subsurface along a geophysical profile were combined in block diagrams. The data sets fit very well and give a first impression of the connection between surface and subsurface structures. Since capturing the subsurface with this method is limited to 2D and the data acquisition is quite time consuming, further investigations are necessary for reliable statements about subterraneous structures, how these may induce surface changes, and the origin of this karst depression. Moreover, geophysical prospecting can only produce a suspected image of the subsurface since the apparent resistivity is measured

  11. Application of Geophysical and Geochemical Prospecting in Hayden Gold Mine%物化探工作在海登金矿勘探中的应用

    Institute of Scientific and Technical Information of China (English)

    杨恺; 李华

    2014-01-01

    海登金矿位于澳大利亚西澳大利亚州佛雷斯特尼亚绿岩带,属于澳洲三级金成矿远景区。综合矿区地质特征、地球物理特征、地球化学特征,圈出异常靶区。通过槽探验证,确定了化探靶区具有直接找矿意义,为本地区寻找石英脉型金矿提供了依据。%The Hayden gold mine is located in the Forrestania greenstone belt in Western Australia State, Australia belongs to third class gold metallogenic prospects. Through mine area geological, geophysical and geochemical characteristics integration has delineat⁃ed anomalous target areas. Through trenching verification has determined that the geochemical anomalous target areas have direct pros⁃pecting significance, thus provided basis for quartz vein typed gold ore deposit prospecting.

  12. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131193 Bing Pingping (Key Lab.of Geophysical Exploration of CNPC , China University of Petroleum , Beijing 102249 , China); Cao Siyuan Non-Linear AVO Inversion Based on Support Vector Machine (Chinese Journal of Geophysics , ISSN0001-5733 , CN11-2074/P , 55 (3), 2012 , p.1025-1032 , 4illus. , 26 tables , 2refs.)

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

    The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significant hydrocarbon discoveries, particularly for Mesozoic sequences, have not been established through conventional exploration due to the thick basalt cover over Mesozoic sedimentary rocks. In this study, near-surface geochemical data are used to understand the petroleum system and also investigate type of source for hydrocarbons generation of the study area. Soil samples were collected from favorable areas identified by integrated geophysical studies. The compositional and isotopic signatures of adsorbed gaseous hydrocarbons (methane through butane) were used as surface indicators of pe-troleum micro-seepages. An analysis of 75 near-surface soil-gas samples was carried out for light hydrocarbons (C1-C4) and their carbon isotopes from the western part of Tapti graben, Deccan Syneclise, India. The geochemical results reveal sites or clusters of sites containing anomalously high concentrations of light hydrocarbon gases. High concentrations of adsorbed thermogenic methane (C1 =518 ppb) and ethane plus higher hydrocarbons (∑C2+=977 ppb) were observed. Statistical analysis shows that samples from 13% of the samples contain anomalously high concentrations of light hydrocarbons in the soil-gas constituents. This seepage suggests largest magnitude of soil gas anomalies might be generated/source from Mesozoic sedimentary rocks, beneath Deccan Traps. The carbon isotopic composition of methane, ethane and propane ranges are from -22.5‰ to -30.2‰PDB, -18.0‰ to 27.1‰ PDB and 16.9‰e-32.1‰ PDB respectively, which are in thermogenic source. Surface soil sample represents the intersection of a migration conduit from the deep subsurface to the surface connected to sub-trappean Mesozoic sedimentary rocks. Prominent hydrocarbon concentra-tions were associated with dykes, lineaments and presented on thinner basaltic cover in the study area, which probably acts as channel for the

  14. Inside the polygonal walls of Amelia (Central Italy): A multidisciplinary data integration, encompassing geodetic monitoring and geophysical prospections

    Science.gov (United States)

    Ercoli, M.; Brigante, R.; Radicioni, F.; Pauselli, C.; Mazzocca, M.; Centi, G.; Stoppini, A.

    2016-04-01

    We investigate a portion of the ancient (VI and IV centuries BC) polygonal walls of Amelia, in Central Italy. After the collapse of a portion of the walls which occurred in January 2006, a wide project started in order to monitor their external facade and inspect the characteristics of the internal structure, currently not clearly known. In this specific case, the preservation of such an important cultural heritage was mandatory, therefore invasive methods like drilling or archaeological essays cannot be used. For this purpose, a multidisciplinary approach represents an innovative way to shed light on their inner structure. We combine several non-invasive techniques such as Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT), specifically adapted for this study, Laser Scanning and Digital Terrestrial Photogrammetry, integrated with other geomatic measures provided by a Total Station and Global Navigation Satellite Systems (GNSS). After collecting some historical information, we gather the whole datasets exploring for their integration an interpretation approach borrowed from the reflection seismic (attribute analysis and three dimensional visualization). The results give rise for the first time to the internal imaging of this ancient walls, highlighting features associable to different building styles related to different historical periods. Among the result, we define a max wall thickness of about 3.5 m for the cyclopic sector, we show details of the internal block organization and we detect low resistivity values interpretable with high water content behind the basal part of the walls. Then, quantitative analyses to assess their reliable geotechnical stability are done, integrating new geometrical constrains provided by the geophysics and geo-technical ground parameters available in literature. From this analysis, we highlight how the Amelia walls are interested, in the investigated sector, by a critical pseudo-static equilibrium.

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

    Directory of Open Access Journals (Sweden)

    T. Satish Kumar

    2014-05-01

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

  16. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    20160511An Yulin(School of Geophysics and Information Technology,China University of Geosciences,Beijing100083,China);Guo Lianghui High Precision Computation and Numerical Value Characteristics of Gravity Emendation Values Arising from Mass of the Earth

  17. Exploration Geophysics

    Science.gov (United States)

    Savit, Carl H.

    1978-01-01

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

  18. Agricultural Geophysics

    Science.gov (United States)

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

  19. EXPLORATION GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20072109 An Yong(Key Lab of Geophysics Exploration under CNPC,China University of Petroleum,Beijing 102249,China);Wei Lichun Most Homogeneous Dip-Scanning Method Using Edge Preserving Smoothing for Seismic Noise Attenuation(Applied Geophysics,ISSN1672-7975,CN11-5212/O,3(4),2006,p.210-217,17 illus.,3 refs.)Key words:seismic exploration,denoising

  20. 综合物探在柳林铀矿勘查中的应用效果%The Application Effect of Geophysical Prospecting Method to the Evaluation of Liulin Uranium

    Institute of Scientific and Technical Information of China (English)

    史剑锋; 施俊生

    2012-01-01

    For further research geological structure and the position development situation of LiuLin uranium area, geophysical methods include radioactive geophysical prospecting and electrical prospecting were used successively. To interpret the data and proof results, analyses the relationship geophysical anomalies and the space distribution of uranium, has achieved the anticipated target. The results show that: high radiation, high polarization and have a certain rule of uranium and thorium, potassium radionuclide secondary halos abnormalities is uranium prospecting marks.%为进一步认识柳林铀矿区地质构造、地下矿体赋存位置及发育情况,对该矿区先后进行了以放射性勘探为主,辅以常规电法勘探等综合物探工作,对测得数据解释推理和成果验证,重点分析了物探异常和铀矿体空间分布的关系,取得了良好效果。结果表明高辐射、高极化和有一定规律的铀、钍、钾放射性核素次生晕异常是本区铀矿的主要找矿标志。

  1. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    20161263Ao Ruide(State Key Laboratory of Marine Geology,Tongji University,Shanghai200092,China);Dong Liangguo Source-Independent Envelope-Based FWI to Build an Initial Model(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,58(6),2015,p.1998-2010,15illus.,18refs.,

  2. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20151907 Bai Yang(Key Laboratory of Petroleum Resources Research,Institute of Geology a nd Geophysics,Chinese Academy of Sci-ences,Beijing100029,China);Song Haibin Structural Characteristics and Genesis of Pockmarks in the Northwest of the South China Sea Derived from Reflective Seismic and Multibeam

  3. From Geophysical Data to Geophysical Informatics

    Directory of Open Access Journals (Sweden)

    Fenglin Peng

    2015-05-01

    Full Text Available Geophysics is based on massive data work including data observation, data gathering/collecting, data management, and data analysis. Over the years, in China and other countries, geophysicists and geophysical institutions have accumulated a huge amount of geophysical data, built up many geophysical data banks and data centers, constructed/established many monitoring and transferring systems and infrastructures of geophysical data, and developed many advanced data analysis methods about data on land, ocean, and space. Based on this work, a new discipline of geophysics, geophysical informatics, has been gradually developing over the past 20 years. The recent advances of geophysical informatics in China are introduced and reviewed in this paper.

  4. 西南岩溶地区不同含水介质地球物理勘查技术%The geophysical prospecting technique in different aquifer media in karst area, Southwest China

    Institute of Scientific and Technical Information of China (English)

    武毅; 孙银行; 李凤哲

    2011-01-01

    针对西南岩溶地区表层带岩溶水、管道型岩溶水(溶洞、暗河、管道等)、构造裂隙岩溶水等不同类型地下水赋存介质特点,通过适宜的地球物理方法使用条件以及找水特点的分析,提出不同含水介质中寻找地下水地球物理勘查要解决的地质问题、拟采用的综合物探方法,分别总结出了它们的电性参数(或曲线)的响应特征,形成了不同含水介质的地球物理勘查技术组合方案.最后通过实例验证其实用性,并对在西南岩溶地区地下水地球物理勘查工作中积累的技术经验进行了总结.%In this paper, based on the characteristics of groundwater occurrence in different media such as epikarst water, pipeline karst water (caves, underground rives, pipelines, etc. ) and structural fissure karst water in Southwest China karst area, the applicability of geophysical methods and the characteristics of water detection are analyzed. And the geological problems in detecting water in different media with geophysical methods and integrated geophysical methods are put forward, and the response characteristic of electrical pa-rameters(or curve) of those methods is summarized. Then the combination program of geophysical methods in different aquifer media is established. Finally, the usefulness of the program is verified and the technique experiences of geophysical prospecting for groundwater in Southwest China karst area are acquired.

  5. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20132654Bi Xiaojia(Chengdu University of Technology,Chengdu 610059,China);Miao Fang Lithology Identification and Mapping by Hyperion Hyperspectral Remote Sensing(Computing Techniques for Geophysical and Geochemical Exploration,ISSN1001-1749,CN51-1242/P,34(5),2012,p.599-603,2illus.,14refs.)Key words:geologic mapping,hyperspectral remote sensing,Qinghai Province

  6. EXPLORATION GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20072798 Chen Fengyun(China University of Mining and Technology,Xuzhou 221008,China);Hang Yuan Algorithm and Application of the Coherency/Variance Cube Technique(Geophysical and Geochemical Exploration,ISSN1000-8918,CN11-1906/P,30(3),2006,p.250-253,257,7 illus.,7 refs.)Key words:seismic exploration The coherency/variance cube technique has been developed in recent years as a new technique of seismic data interpretation.

  7. From Geophysical Data to Geophysical Informatics

    OpenAIRE

    Peng, Fenglin; Peng, Le; Zhang, Jian; Xue, Guoqiang; Ma, Maining; Zhang, Yunfei

    2015-01-01

    Geophysics is based on massive data work including data observation, data gathering/collecting, data management, and data analysis. Over the years, in China and other countries, geophysicists and geophysical institutions have accumulated a huge amount of geophysical data, built up many geophysical data banks and data centers, constructed/established many monitoring and transferring systems and infrastructures of geophysical data, and developed many advanced data analysis methods about data on...

  8. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110471 Cai Shaokun(Mechatronics and Automation College,National University of Defense Technology,Changsha 410073,China);Wu Meiping A Comparison of Digital Lowpass FIR-Filters in Airborne Gravimetry(Geophysical and Geochemical Exploration,ISSN1000-8918,CN11-1906/P,34(1),2010,p.74-78,8 illus.,3 tables,14 refs.)Key words:aerogravity surveys,filtersThere is a lot of noise in the data observed by airborne gravimeter.Digital lowpass FIR-filter i

  9. Application Effect of Geophysical Method in Urban Geological Hazard Prospecting%城市地质灾害勘察中地球物理方法的应用效果

    Institute of Scientific and Technical Information of China (English)

    毕明丽

    2014-01-01

    The urban geological hazard is mostly caused by human, and the common hazards are earthquakes, ground deformation, debris flow, water and soil erosion, deterioration of groundwater resources, seawater intrusion, and so on, which has certain potentiality, suddenness, concealment and harmfulness. Geophysical techniques have a positive effect on geological hazard monitoring, forecasting and prevention. This paper analyses the application effect of geophysical method in urban geological hazard prospecting, thus promoting the orderly running of geological hazards prospecting.%城市地质灾害大多数都是由于人为引起的,常见的有地震、地面变形、泥石流、水土流失、地下水资源恶化、海水入侵等,具有一定的潜在性、突发性、隐蔽性以及危害性。地球物理技术对地质灾害的监测、预报以及防治具有积极的作用。本文就城市地质灾害勘察中地球物理方法的应用效果进行了研究分析,从而促进地质灾害勘察工作有序进行。

  10. Petroleum geophysics

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    The book is compiled from a series of e-learning modules. GeoCLASS is an e-learning system with contents from petroleum geophysics. It is the result of collaboration between professors at the University of Bergen and the University of Oslo, and its material has been used as curriculum in master program courses at these universities for several years. Using a unique feature to GeoCLASS, these advanced scientific topics are presented on multiple levels. The introductions open the door to this vast pool of knowledge, accessible even for high school students. Enter the door, and you enter the modules. Various levels of content are presented, and the more advanced levels can be shielded from the regular user, and only accessed by those with particular interest. The chapters in the book are: Elastic waves; Survey planning; Seismic acquisition; Basic seismic signal theory and processing; Seismic imaging; Seismic attributes; Rock physics; Reservoir monitoring. (AG)

  11. Application of geophysical prospecting in Nam Co western ophiolite belt for nickel ore%物探在纳木错西部蛇绿岩片带中找镍铁矿的应用

    Institute of Scientific and Technical Information of China (English)

    陈跃龙; 贺淑兰

    2014-01-01

    Because this area is located in the Qinghai Tibet Plateau, the ecological environment is extremely fragile. The grass covered vast majority of ground, from protect environment point of view, is not suitable the surface engineering exposure. According to the lithology and mineral features, physical property of Jade Gula ophiolite belt and wall rock, apply scientific geophysical prospecting method to delineate geophysical anomaly, directly using drilling method to disclosed, which in this district has achieved obvious prospecting effect, also provide the precious experience for the delineation of new exploration target region of Nam Co western ophiolite belt, and get out of a new prospecting model of mineral resources exploitation and environmental protection in Qinghai Tibet Plateau.%由于本区地处青藏高原,生态环境极为脆弱,地表绝大部分为草坪覆盖,从保护环境的角度出发不易动用地表工程揭露。根据玉古拉蛇绿岩片带、围岩岩性及矿产特点、物性特征等,确定在本区找矿运用科学的物探方法圈定物探异常后,直接运用钻探揭露的方法,既在本区取得了明显的找矿效果,也为纳木错西部蛇绿岩片带圈定新的勘探靶区提供了宝贵的经验,又在青藏高原走出了一条矿产开发与环境保护的新型找矿模式。

  12. Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J.D. [Sandia National Labs., Albuquerque, NM (United States); Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A. [Geomatrix Consultants, Inc., San Francisco, CA (United States)

    1992-01-01

    Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques.

  13. Application of geophysical methods to gold prospecting in Minas de Corrales, Uruguay; Aplicacao de metodos geofisicos a prospeccao de ouro. Teste nas minas de Corrales, Uruguai

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Antonio Flavio U. [Companhia de Pesquisas de Recursos Minerais (CPRM), Rio de Janeiro, RJ (Brazil); Dias, Rogerio Aguirre; Barcelos, Andre B.B. de [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil)

    1993-07-01

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

  14. 浅析综合物探技术在地下管线探测中的应用%Superficial Analysis of the Application of Integrated Geophysical Prospecting Technology in Underground Pipeline Detection

    Institute of Scientific and Technical Information of China (English)

    李双超; 吴露

    2015-01-01

    迅速了解地下管线的布置情况,是今后城市建设中的必然要求.在地下管线的探测中,综合物探技术的运用起到了非常重要的作用.因此,分析了地下管线的分类、探测特征及其常用探测方法,并对提高探测质量的方法进行了阐述.%Rapid understanding of the layout of the underground pipeline is the inevitable requirement of the construction of the city in the future. In the exploration of underground pipelines, the application of integrated geophysical prospecting technology plays a very important role. Therefore, this paper analyzes the classification of underground pipelines, detection characteristics and common detection methods, and to improve the quality of detection methods are described.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-27

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

  16. Handbook of Agricultural Geophysics

    Science.gov (United States)

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

  17. 综合物探技术在山西某整合矿井的应用%Application of Integrated Geophysical Prospecting Technology in a Reintegrated Coalmine in Shanxi

    Institute of Scientific and Technical Information of China (English)

    石君华

    2012-01-01

    山西某整合矿井地表条件复杂,目的层埋深变化大,部分区段煤层埋藏较浅,且有采空区存在,为解决该矿地质构造、采空区范围及其富水性以及影响煤层开采的其它水文地质问题,采用三维地震勘探与瞬变电磁法、直流电测深法相结合的综合物探技术.利用三维地震勘探解决目的层赋存形态及其地质构造问题;再利用瞬变电磁法进行平面控制,以使平面及深度解释误差达到勘探要求;应用直流电测深法及瞬变电磁进行勘探,在正反演解释的基础上对其资料综合分析、对比,并结合三维地震资料,确定地质构造的富水及导水性,取得了较好勘探效果.%A reintegrated coalmine in Shanxi has complicated surface condition, varied target buried depth, coal seam buried depth is rather shallow in part of the coalmine, and the existing of gob areas. To figure out geological structure, gob area extent and its water yield property, as well as other hydrogeologica] issues impacting coal mining, the integrated geophysical prospecting technology including 3D seismic prospecting and transient electromagnetic method, galvanic electric sounding has been used. Using 3D seismic prospecting figured out target hosting configuration and geological structure; then using transient electromagnetic method carried out planar control, making the planar and depth interpretation errors meet the prospecting requirement; using galvanic electric sounding and transient electromagnetic methods carried out data comprehensive analysis, contrast on,the forward and inversion interpreted basis, combined with 3D seismic data, defined geological structures' water yield property and conductivity and obtained preferable prospecting effect.

  18. BGP Better Positioned to Compete with Geophysical Giants Worldwide

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Bureau of Geophysical Prospecting (GGP), a subsidiary under CNPC, has seen satisfactory results in development of international exploration market in the first three quarters of this year with the success rate of international bidding reaching 61 percent.

  19. An application of neural network in geophysical prospecting. Electrical resistivity at Las Virgenes geothermal field, Baja California Sur, Mexico; Una aplicacion de las redes neuronales a la prospeccion geofisica. Resistividad electrica en las Tres Virgenes, Baja California Sur, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Palma Guzman, Sergio Hugo [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    2000-12-01

    The technology of the neural network is presented with geophysical focus in the Las Virgenes geothermal field, Baja California Sur, Mexico. The results obtained when extrapolating the associative data of the prospecting magnetoteluria and Vertical Electric Sounding, on the area of the geothermal wells to the rest of the area, allows to classify zones of interest for the geothermal exploitation. Also, the use of these associative parameters with the information of the stabilized temperature of the wells, they allow to predict temperatures for the rest of the area. [Spanish] Se presenta una aplicacion de la tecnologia de las redes neuronales con enfoque geofisico en el campo geotermico de Las Virgenes, Baja California Sur, Mexico. Los resultados obtenidos al extrapolar los datos asociativos de las prospecciones geoelectricas de magnetoteluria y sondeos electricos verticales, en la zona de los pozos geotermicos al resto del area, permiten clasificar zonas de interes para la explotacion geotermica. Tambien, la utilizacion de estos parametros asociativos con la informacion de la temperatura estabilizada de los pozos, permiten predecir temperaturas para la misma area.

  20. Advances in geophysics

    CERN Document Server

    Sato, Haruo

    2013-01-01

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

  1. Fiber optic geophysical sensors

    Science.gov (United States)

    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.

  2. Advances in geophysics

    CERN Document Server

    Sato, Haruo

    2012-01-01

    The critically acclaimed serialized review journal for over 50 years, Advances in Geophysics is a highly respected publication in the field of geophysics. Since 1952, each volume has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now in its 52nd volume, it contains much material still relevant today--truly an essential publication for researchers in all fields of geophysics.Key features: * Contributions from leading authorities * Informs and updates on all the latest developments in the field

  3. Waterberg coalfield airborne geophysics

    CSIR Research Space (South Africa)

    Fourie, S

    2009-07-01

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

  4. Geophysical Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Geophysical Research Facility (GRF) is a 60 ft long qaodmasdkwaspemas5ajkqlsmdqpakldnzsdfls 22 ft wide qaodmasdkwaspemas4ajkqlsmdqpakldnzsdfls 7 ft deep concrete...

  5. Geophysics in INSPIRE

    Science.gov (United States)

    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

  6. Geophysical Research Facility

    Data.gov (United States)

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

  7. Sensitivity analysis and application in exploration geophysics

    Science.gov (United States)

    Tang, R.

    2013-12-01

    local anomalies of various physical property of a geological formation. Through a large number of modeling on the varied parameter choosing in each geophysical method, a common survey layout of different methods in a specified area is then optimized. As can be seen from the sensitivity analysis of assorted models of each method, we also found that different geophysical methods are sensitive to different underground structure, which suggests each method may provide complementary information on the same geological structure. In conclusion, we have shown that sensitivity analysis can be used in the assessment of inverse solution and design strategies of joint geophysical prospecting.

  8. Applied Research Projects Geology Hydrogeology Geophysical Prospecting Techniques%滑坡工程地质水文地质勘察中物探技术的应用研究

    Institute of Scientific and Technical Information of China (English)

    周中成

    2015-01-01

    The application of geophysical techniques in landslide hydrogeologic survey conducted in-depth Research, and groundwater monitoring changes in the role of geophysical technology has a simple, with an aim to further promote the development of geophysical technology in hydrogeological survey.%对物探技术在滑坡地质水文地质勘察中的应用进行了深入研究,并对物探技术具有的地下水变化监测作用进行了简单探讨,旨在进一步推动物探技术在水文地质勘察中的应用发展。

  9. Integrated Approaches On Archaeo-Geophysical Data

    Science.gov (United States)

    Kucukdemirci, M.; Piro, S.; Zamuner, D.; Ozer, E.

    2015-12-01

    Key words: Ground Penetrating Radar (GPR), Magnetometry, Geophysical Data Integration, Principal Component Analyse (PCA), Aizanoi Archaeological Site An application of geophysical integration methods which often appealed are divided into two classes as qualitative and quantitative approaches. This work focused on the application of quantitative integration approaches, which involve the mathematical and statistical integration techniques, on the archaeo-geophysical data obtained in Aizanoi Archaeological Site,Turkey. Two geophysical methods were applied as Ground Penetrating Radar (GPR) and Magnetometry for archaeological prospection on the selected archaeological site. After basic data processing of each geophysical method, the mathematical approaches of Sums and Products and the statistical approach of Principal Component Analysis (PCA) have been applied for the integration. These integration approches were first tested on synthetic digital images before application to field data. Then the same approaches were applied to 2D magnetic maps and 2D GPR time slices which were obtained on the same unit grids in the archaeological site. Initially, the geophysical data were examined individually by referencing with archeological maps and informations obtained from archaeologists and some important structures as possible walls, roads and relics were determined. The results of all integration approaches provided very important and different details about the anomalies related to archaeological features. By using all those applications, integrated images can provide complementary informations as well about the archaeological relics under the ground. Acknowledgements The authors would like to thanks to Scientific and Technological Research Council of Turkey (TUBITAK), Fellowship for Visiting Scientists Programme for their support, Istanbul University Scientific Research Project Fund, (Project.No:12302) and archaeologist team of Aizanoi Archaeological site for their support

  10. Geophysical Methods: an Overview

    Science.gov (United States)

    Becker, A.; Goldstein, N. E.; Lee, K. H.; Majer, E. L.; Morrison, H. F.; Myer, L.

    1992-01-01

    Geophysics is expected to have a major role in lunar resource assessment when manned systems return to the Moon. Geophysical measurements made from a lunar rover will contribute to a number of key studies: estimating regolith thickness, detection of possible large-diameter lava tubes within maria basalts, detection of possible subsurface ice in polar regions, detection of conductive minerals that formed directly from a melt (orthomagmatic sulfides of Cu, Ni, Co), and mapping lunar geology beneath the regolith. The techniques that can be used are dictated both by objectives and by our abilities to adapt current technology to lunar conditions. Instrument size, weight, power requirements, and freedom from orientation errors are factors we have considered. Among the geophysical methods we believe to be appropriate for a lunar resource assessment are magnetics, including gradiometry, time-domain magnetic induction, ground-penetrating radar, seismic reflection, and gravimetry.

  11. Asteroid Surface Geophysics

    CERN Document Server

    Murdoch, Naomi; Schwartz, Stephen R; Miyamoto, Hideaki

    2015-01-01

    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 micro-gravity environment that these bodies posses, 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 hypothesised 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 towards 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...

  12. SICHUAN GEOPHYSICAL COMPANY

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Sichuan Geophysical Company (abbreviated as SCGC below), originally named Sichuan Geophysical Company of CNPC Sichuan Petroleum, was founded in 1956 and is a subsidiary of CNPC Chuanqing Drilling Engineering Company Limited. With more than 50 years' development, SCGC now owns almost 3800 employees and has become a big oil & gas seismic exploration engineering service enterprise with the characteristic mountain seismic exploration techniques, and its annual business turnover reaches nearly 2 billion RMB. It can provide the integrated seismic exploration engineering service including seismic data acquisition, processing, interpretation, and geological comprehensive evaluation in various complex regions for clients at home and abroad.

  13. Accurate Detection of the Goaf of Gongchangling Open-pit Based on the Comprehensive Geophysical Prospecting Method%利用综合物探法精准探测弓长岭露天矿采空区

    Institute of Scientific and Technical Information of China (English)

    张德辉; 朱帝杰

    2015-01-01

    In order to detect the goaf of Gongchangling open-pit accurately,the comprehensive geophysical prospecting method based on high density resistivity method and transient electromagnetic method is proposed. Firstly,according to the high density resistivity method,the low resistance model and high resistance model of single goaf and double goaf under all kinds of geological conditions based on the detection data obtained by the devices of wenner,dipole array and unilateral tertiary,the goaf of Gongchangling open-pit distributed densely in horizontal and vertical direction is detected by conducting contrast analysis of the resistivity difference;secondly,based on transient electromagnetic method,the geological and geophysical recognition model of the same geological body are established by utilizing the devices of coincident loop,central loop,separate loop and ground loop,and the location and scale of the goaf of Guangchangling open-pit are detected accurately by observing the variation infor-mation of the transient magnetic field structure and frequency along with time and space;finally,in order to detect the informa-tion of location,scale and roof thickness with high precision,the comprehensive detection data of high density resistivity method and transient electromagnetic method are processed and interpreted comprehensively combing with the field actual geological conditions. The cross-section diagram and floor plan of the goaf of Gongchangling open-pit are obtained. The detection results show that 3 shallow goafs and 2 deep goafs are detected in Gongchangling open-pit,so it can be further indicated that the inte-gration of comprehensive and advantages of detecting technologies is realized by the organic combination of high density method and transient electromagnetic method. It is good to conduct the detection of goaf with high precision.%为了对弓长岭露天矿采空区进行精准探测,首先根据高密度电阻率法,利用温纳、偶极、单边三极

  14. Arizona Geophysical Data Base

    OpenAIRE

    McLeod, Ronald G.

    1981-01-01

    A series of digital data sets were compiled for input into a geophysical data base for a one degree quadrangle in Arizona. Using a Landsat digital mosaic as a base, information on topography, geology, gravity as well as Seasat radar imagery were registered. Example overlays and tabulations are performed.

  15. Reconciling Impact Evidence and Meteorite Strewnfield in Agoudal (Morocco): Field, Geomorphology and Geophysical Evidences

    Science.gov (United States)

    Rochette, P.; Chennaoui Aoudjehane, H.; El Kerni, H.; Quesnel, Y.; Uehara, M.; Aboulharis, M.; Hutzler, A.; Bourles, D.

    2014-09-01

    We present a synthesis of the field observations, magnetic and electromagnetic geophysical prospection, and ongoing measurements to discuss the likelyhood that the Agoudal impact and meteorite strewnfield are the same event, dated within Pleistocene.

  16. Rapid geophysical surveyor

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-01-01

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

  17. Rapid geophysical surveyor

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-07-01

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

  18. Geophysical wave tomography

    Science.gov (United States)

    Zhou, Chaoguang

    2000-11-01

    This study is concerned with geophysical wave tomography techniques that include advanced diffraction tomography, traveltime calculation techniques and simultaneous attenuation and velocity tomography approaches. We propose the source independent approximation, the Modified Quasi-Linear approximation and develop a fast and accurate diffraction tomography algorithm that uses this approximation. Since the Modified Quasi-Linear approximation accounts for the scattering fields within scatterers, this tomography algorithm produces better image quality than conventional Born approximation tomography algorithm does with or without the presence of multiple scatterers and can be used to reconstruct images of high contrast objects. Since iteration is not required, this algorithm is efficient. We improve the finite difference traveltime calculation algorithm proposed by Vidale (1990). The bucket theory is utilized in order to enhance the sorting efficiency, which accounts for about ten percent computing time improvement for large velocity models. Snell's law is employed to solve the causality problem analytically, which enables the modified algorithm to compute traveltimes accurately and rapidly for high velocity contrast media. We also develop two simultaneous attenuation and velocity tomography approaches, which use traveltimes and amplitude spectra of the observed data, and discuss some of their applications. One approach is processing geophysical data that come from one single survey and the other deals with the repeated survey cases. These approaches are nonlinear and therefore more accurate than linear tomography. A linear system for wave propagation and constant-Q media are assumed in order to develop the tomography algorithms. These approaches not only produce attenuation and velocity images at the same time but also can be used to infer the physical rock properties, such as the dielectric permittivity, the electric conductivity, and the porosity. A crosshole radar

  19. Geophysics publications honored

    Science.gov (United States)

    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.

  20. International Symposium on Airborne Geophysics

    Science.gov (United States)

    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.

  1. 煤巷空间地质异常体超前综合物探研究与应用%The applied research of fore detecting geologic abnormal body with comprehensive geophysical prospecting method in coal roadway space

    Institute of Scientific and Technical Information of China (English)

    张孝广

    2016-01-01

    在煤矿开采过程中,80%以上事故发生在煤巷掘进中,主要原因是对井下地质条件不清,盲目掘进。为解决重点区域掘进过程中透水突泥,煤岩突出,冲击地压等地质异常灾害,很有必要开展煤巷综合物探研究。本文主要介绍地震反射波、瞬变电磁、直流电法在成庄矿5312巷综合超前探测中具体研究应用与揭露验证,保障了井巷安全快速高效掘进。%In the process of coal mining, more than 80% of the accident in drivage roadway, mainly for the unclear underground geological conditions, blind tunneling. To solve the problem in the process of excavating permeable clay, coal and rock, geological disasters, such as impact ground pressure, it is necessary to carry out the integrated geophysical research. This paper mainly introduces the seismic reflection wave, transient electromagnetic,direct current method in Chengzhuang coal mine of lane 5312 comprehensive geophysical fore detecting of specific application and veriifcation,to ensure the safety of mine tunneling and efifciently.

  2. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1979-01-01

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

  3. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1982-01-01

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

  4. Sampling functions for geophysics

    Science.gov (United States)

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

    1972-01-01

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

  5. Geophysics of Mars

    Science.gov (United States)

    Wells, R. A.

    1979-01-01

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

  6. Serious games for Geophysics

    Science.gov (United States)

    Lombardo, Valerio; Rubbia, Giuliana

    2015-04-01

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

  7. Sustainable Geophysical Observatory Networks

    Science.gov (United States)

    Willemann, R. J.; Lerner-Lam, A.; Aster, R.; Beck, S.; Ekstrom, G.; Nyblade, A.; Sandvol, E.

    2007-05-01

    Geophysical networks are defined not only by their technical specifications, but also by the characteristics and needs of the communities that use them. Growing populations supported by more elaborate urban infrastructure with its fine-grained socio-economic interdependencies and relying on global and regional connections for sustainability make new demands for natural hazard risk management. Taking advantage of advances in the underlying science to provide society with accurate risk assessments often requires higher fidelity measurements, entirely new types of observations, and an evolutionary sense of data products and information management. Engineering a high-tech system to address stakeholder needs is difficult, and designing for unpredictable developments requires an emphasis on adaptation. Thus, it is essential to promote formation of organizations or communities that can support evolution of a technological system, imagine new uses, and develop the societal relationships that sustain operations and provide capital for improvement. The owners must have a deep understanding of why the system works in particular ways and how to manage data products for the benefits of stakeholders. To be effective, community promotion must be sustained over a longer period of time than required to build a network and should be aimed at integrating the community into worldwide partnerships. Practices that can promote community formation if they are sustained include repeated training and scientific exchange workshops, extended visits by experts and staff at all levels to and from countries where networks are installed, mechanisms that make timely upgrades realistically possible, and routine exchange and wide dissemination of data in all directions. The combination of international research and educational collaborations, supported by open data exchange, with regionalized and specific assessments of local stakeholder needs and concerns, provides a sustainable model for

  8. Developments in geophysical exploration methods

    CERN Document Server

    1982-01-01

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

  9. ANNALS OF GEOPHYSICS: AD MAJORA

    Directory of Open Access Journals (Sweden)

    Fabio Florindo

    2014-03-01

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

  10. Jesuit Geophysical Observatories

    Science.gov (United States)

    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.

  11. Geophysical lineaments of Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Lepley, L.K.

    1979-08-01

    Photolineaments seen on satellite images are usually expressions of deep crustal ruptures. However, photolineaments are omnipresent and an independent expression of regional discontinuities is needed to help rank the photolineaments. Published gravity and magnetic contour maps of Arizona were analyzed to produce a single geophysical lineament map to indicate trends of regional basement structures. This map shows that the southwestern quarter of Arizona is dominated by a NNW-ENE orthogonal system whereas the remainder of the state is gridded by a NW-NE system. North-south systems are present throughout the state, as are EW lineaments. Arizona is transected by the WNW Texas Strand, but other shorter systems trending in the Texas direction are found throughout the state south of the Strand. The major lineament systems as seen on Landsat, gravity, and magnetic maps correlate reasonably well with known geothermal manifestations. Many other systems are Precambrian, Paleozoic, and/or Mesozoic in age but appear to control the location of Quaternary volcanic systems.

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

    Science.gov (United States)

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

    2007-05-01

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

  13. GEOTECHNICAL EXAMINATION OF THE GEOPHYSICAL ...

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... olokoro lateritic soil, particle size distribution, compaction test, geophysical properties, california bearing ratio. 1. ... e.g. alluvial soil, aeolin soil, glacial soil etc. [2]. .... Garg, S.K. Soil Mechanics and Foundation Engineer- ing.

  14. Investigation on a Novel Capacitive Electrode for Geophysical Surveys

    Directory of Open Access Journals (Sweden)

    Zhiyu Wang

    2016-01-01

    Full Text Available Nonpolarizable electrodes are applied widely in the electric field measurement for geophysical surveys. However, there are two major problems: (1 systematic errors caused by poor electrical contact in the high resistive terrains and (2 environmental damage associated with using nonpolarizable electrodes. A new alternative structure of capacitive electrode, which is capable of sensing surface potential through weak capacitive coupling, is presented to solve the above problems. A technique is introduced to neutralize distributed capacitance and input capacitance of the detection circuit. With the capacitance neutralization technique, the transmission coefficient of capacitive electrode remains stable when environmental conditions change. The simulation and field test results indicate that the new capacitive electrode has an operating bandwidth range from 0.1 Hz to 1 kHz. The capacitive electrodes have a good prospect of the applications in geophysical prospecting, especially in resistive terrains.

  15. Geophysical prospecting method in intrusive rocks area fight a drought to find water wells set%物探方法在侵入岩地区抗旱找水定井中的应用

    Institute of Scientific and Technical Information of China (English)

    宋希利; 宋鹏; 田明阳; 彭玉明

    2012-01-01

    Intrusive rocks in the area of groundwater is difficult to find, but more abundant in the dry season the groundwater more difficult to find, to quickly resolve severe drought disaster in Shandong Yimcngshan people much-needed human and livestock water consumption through advanced and effective geophysical methods and reasonable working arrangement greatly increased drought in the intrusive rocks in the area to find water wells set the speed and rate guarantees as well, by the construction of drilling results verify the geophysical inference realistic, given the success rate of 96% well, single-well water yield are far beyond the estimated amount of water, to find a more extensive local groundwater resources, water resources needed to solve the problem of the masses, the people and the old liberated areas have been highly appreciated by the local government. Proved Yimengshan intrusive rocks in the area of geophysical methods based on different characteristics and be well area is difficult, easy, and CSAMT method were selected degree of resistivity sounding method to find underground water source not only improves the speed and success rate of well set, but also made good hydrogeological effects, it is in similar application areas. Practical work in the specific practice, one can not determine the geological survey of the ground target range and set well drilling difficult areas, the use of controlled source audio magnetotelluric: method is fast and efficient features, to sweep the work surface, suggesting that rock construction of fracture zone, delineated area that is rock crushing low resistance, water lots, and to determine the depth of drilling wells; the second is on the ground within the geological survey to determine, using the resistivity sounding method, the use of a single curve reflects the broken rocks, water section to determine the visual characteristics of the aquifer and depth.%侵入岩地区寻找地下水难度大,而在干旱季节找出较为

  16. Planetary Geophysics and Tectonics

    Science.gov (United States)

    Zuber, Maria

    2005-01-01

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

  17. Sustainable urban development and geophysics

    Science.gov (United States)

    Liu, Lanbo; Chan, L. S.

    2007-09-01

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

  18. Minimax approach to inverse problems of geophysics

    Science.gov (United States)

    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.

  19. Optimization and geophysical inverse problems

    Energy Technology Data Exchange (ETDEWEB)

    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

  20. Borehole geophysics for delineating the geological structure in the Sakonishi prospect, the Hida area, Japan; Hida chiiki Sako nishi chiku ni okeru boring ko riyo butsuri tansa ni yoru chishitsu kozo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, H.; Hishida, H.; Yoshioka, K. [Metal Mining Agency of Japan, Tokyo (Japan)

    1997-05-27

    In order to discuss effectiveness of physical exploration in the Sakonishi prospect in the Hida area, physical exploration was carried out by utilizing bored wells. This area contains the Kamioka mine, one of the major base metal mines in Japan, where electrical exploration has been attempted several times in the past. No effective results have been obtained, however, because specific resistance contrast between mine beds and base rocks is too small, and the topography is too steep making site workability inferior. As part of the investigations on geological structures over wide areas, electrical logging (specific resistance and natural potential) was performed in fiscal 1995 and 1996 by utilizing the boreholes. Induced polarization logging was also conducted on the same boreholes. A traverse line on the ground with a length of 600 m and boreholes were used to execute specific resistance tomography. Clear extraction was possible on a fault structure which is thought related with limestone distribution and mine bed creation. However, it was not possible to identify upward continuity of zinc ores expected in the exploration. Because of not large a specific resistance contrast between zinc ores and base rocks, it is difficult to find mine bed locations only from the information on the specific resistance. 5 refs., 5 figs., 1 tab.

  1. Fiber Optic Geophysics Sensor Array

    Science.gov (United States)

    Grochowski, Lucjan

    1989-01-01

    The distributed optical sensor arrays are analysed in view of specific needs of 3-D seismic explorations methods. There are compared advantages and disadventages of arrays supported by the sensors which are modulated in intensity and phase. In these systems all-fiber optic structures and their compabilities with digital geophysic formats are discussed. It was shown that the arrays based on TDM systems with the intensity modulated sensors are economically and technically the best matched for geophysic systems supported by a large number of the sensors.

  2. A GEOPHYSICAL COMPANY FOR TODAY AND TOMORROW

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ BGP is one of the world leading onshore geophysical service contractors with a registered capital of 5,100 million Yuan. In 2002, BGP became a liability-limited company after merging other six Chinese geophysical companies.

  3. A New Social Contract for Geophysics

    Science.gov (United States)

    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.

  4. Geophysical Institute. Biennial report, 1993-1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

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

  5. Prospección geológica y geofísica de sulfuros en el área de Virorco-La Bolsa, provincia de San Luis Geological and geophysical sulfide prospection in the Virorco-La Bolsa area, San Luis province

    Directory of Open Access Journals (Sweden)

    J. Kostadinoff

    2005-09-01

    Full Text Available En los cuerpos máficos-ultramáficos del área de Virorco y La Bolsa, bloque central de la sierra de San Luis, se han detectado sulfuros polimetálicos en venillas y diseminados. Como herramienta de prospección geofísica se utilizó el método de autopotencial en combinación con estudios geomagnéticos. Los lentes máfico-ultramáficos están enmarcados por una caja gnéisicamigmatítica de alto grado. Una foliación milonítica de rumbo NNE y buzamiento de alto ángulo al ESE, afecta al basamento y también a los bordes de los cuerpos máfico-ultramáficos. Hacia el interior de estos últimos, alternan sectores que preservan las texturas granulares ígneas y una foliación buzante al oeste, con fajas de cizalla con foliación milonítica buzante al ESE. El estudio geofísico en Virorco indica una correspondencia entre los valores de autopotencial negativos (-150 mV y los máximos de magnetismo terrestre (+350 nT. En la zona de La Bolsa se realizaron dos perfiles de autopotencial, los cuales muestran un núcleo de autopotencial negativo de entre -40 y -55 mV, ligeramente alargado y buzante al ESE. Sobre el margen oriental, un valor de -90 mV constituye el núcleo de una anomalía alargada y también buzante al ESE. La disposición espacial de estas anomalías es coincidente con la orientación de la foliación milonítica. La correspondencia establecida con esta nueva herramienta de prospección, sustenta la removilización y concentración de los sulfuros primarios diseminados durante el evento de milonitización, ya planteada previamente en base a otras técnicas de estudio.In the Virorco and La Bolsa mafic-ultramafic bodies, central block of the Sierra de San Luis, polymetallic sulfides occur in veinlets and disseminated. The autopotential method in combination with geomagnetic studies, were utilized as geophysical prospection tools. The maficultramafic lenses are surrounded by high-grade gneissic-migmatitic country-rocks. A penetrative

  6. 综合物探法在平朔东露天矿铁路专用线煤窑采空区探测的应用%Comprehensive geophysical prospecting method in special railway line of coalpit goaf detection application of pingshuo eastern open-pit coal mine

    Institute of Scientific and Technical Information of China (English)

    刘波; 高永涛; 金爱兵; 白哲; 邓富根

    2012-01-01

    小煤窑的无序无证开采,形成的采空区等地质异常体常成为公路、铁路等工程安全施工和长久运营的安全隐患.为解决上述问题,本文通过对测区浅部采空区采用探地雷达和AGI高密度电法、测区深部采空区采用EH4电磁成像系统的综合物探方法,得到了采空区分布的剖面图,划分了重点异常区,取得了令人满意的探测结果,为后期有针对性、有目的性地对采空区进行治理提供了保障.%Disordered mining of small coalpits without a license formed geological anomalous bodies such as the goaf which often brings hidden danger to highway, railway and other engineering construction and long operation. In order to solve the problem above, this article applies the comprehensive geophysical prospecting method that it measures the shallow goaf of sensing area by using the ground penetrating radar and AGI high density resistivity method and measures deep goaf by using EH4 Electromagnetic image system. As a result, it obtained distribution profiles of the goaf, divided key areas of abnormality and achieved satisfactory detection. At last it provides safety and security purposefully for the management of gob area.

  7. Geophysical images of basement rocks. Geophysical images in the Guianese basement. Airborne geophysical campaign in French Guiana - 1996; Images geophysiques de socles. Images geophysiques dans le socle guyanais. Campagne de geophysique aeroportee en Guyane francaise - 1996

    Energy Technology Data Exchange (ETDEWEB)

    Delor, C.; Perrin, J.; Truffert, C.; Asfirane, F.; Rossi, Ph.; Bonjoly, D.; Dubreuihl, J. [Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France); Chardon, D

    1998-08-01

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

  8. 综合物探方法在云南江城隐伏铅锌矿勘查中的应用%The effects of applying integrated geophysical method to the prospecting for the Jiangcheng concealed lead and zinc deposit in Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    李星; 王峰; 罗大锋; 解康; 牛杰; 高明山; 杨锁

    2015-01-01

    In order to accelerate the prospecting work for the Yanjiao mining area in Jiangcheng City, the authors made full use of the integrated geophysical method. First, the authors delineated three exploration target areas by using high power TD IP method. Then the authors studied the ore-controlling structure in the target and its extension through AMT to find favorable metallogenic area. Drilling ver-ification led to the discovery of three concealed Pb-Zn orebodies. 5.766 million tons of the 122 b+333 class industrial sulfur lead-zinc resources are added to the reserves of the ore deposit. The results obtained by the authors show that we can quickly identify lead-zinc a-nomaly body, which provides the basis for further prospecting engineering through IP method and AMT method. This is one of the effec-tive methods to find the same type of ore deposits.%为加快江城岩脚矿区探矿工作步伐,取得找矿突破,采用综合物探方法进行勘查. 首先,通过大功率激电中梯扫面,初步圈定了3个目标靶区;然后,采用音频大地电磁测深法研究靶区的控矿构造及其在深部的延伸情况,从而寻找成矿有利部位;在推测的成矿有利部位进行钻孔验证,共发现隐伏铅锌矿体3个,矿区较原来新增122b+333类工业硫化铅锌矿矿石量576.60万t. 该矿区勘查结果表明,激电法与音频大地电磁测深法的联合应用,可以快速圈定深部铅锌多金属矿化异常体,并为后期探矿工程部署提供依据,是寻找同类型矿床的有效方法之一.

  9. Near-surface applied geophysics

    CERN Document Server

    Everett, Mark E.

    2013-01-01

    Just a few meters below the Earth's surface lie features of great importance, from geological faults which can produce devastating earthquakes, to lost archaeological treasures! This refreshing, up-to-date book explores the foundations of interpretation theory and the latest developments in near-surface techniques, used to complement traditional geophysical methods for deep-exploration targets. Clear but rigorous, the book explains theory and practice in simple physical terms, supported by intermediate-level mathematics. Techniques covered include magnetics, resistivity, seismic reflection and refraction, surface waves, induced polarization, self-potential, electromagnetic induction, ground-penetrating radar, magnetic resonance, interferometry, seismoelectric and more. Sections on data analysis and inverse theory are provided and chapters are illustrated by case studies, giving students and professionals the tools to plan, conduct and analyze a near-surface geophysical survey. This is an important textbook fo...

  10. New Geophysical Observatory in Uruguay

    Science.gov (United States)

    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. Geophysical fields of a megalopolis

    Science.gov (United States)

    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.

  12. Geophysical interpretation using integral equations

    CERN Document Server

    Eskola, L

    1992-01-01

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

  13. Geophysical monitoring technology for CO2 sequestration

    Science.gov (United States)

    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.

  14. Geophysical examination of coal deposits

    Science.gov (United States)

    Jackson, L. J.

    1981-04-01

    Geophysical techniques for the solution of mining problems and as an aid to mine planning are reviewed. Techniques of geophysical borehole logging are discussed. The responses of the coal seams to logging tools are easily recognized on the logging records. Cores for laboratory analysis are cut from selected sections of the borehole. In addition, information about the density and chemical composition of the coal may be obtained. Surface seismic reflection surveys using two dimensional arrays of seismic sources and detectors detect faults with throws as small as 3 m depths of 800 m. In geologically disturbed areas, good results have been obtained from three dimensional surveys. Smaller faults as far as 500 m in advance of the working face may be detected using in seam seismic surveying conducted from a roadway or working face. Small disturbances are detected by pulse radar and continuous wave electromagnetic methods either from within boreholes or from underground. Other geophysical techniques which explicit the electrical, magnetic, gravitational, and geothermal properties of rocks are described.

  15. Rapid Geophysical Surveyor. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-01-01

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

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

    Science.gov (United States)

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

    2005-12-01

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

  17. Magnetotellurics as a multiscale geophysical exploration method

    Science.gov (United States)

    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).

  18. Neutrino geophysics with KamLAND and future prospects

    CERN Document Server

    Enomoto, S; Inoue, K; Suzuki, A

    2005-01-01

    The Kamioka liquid scintillator anti-neutrino detector (KamLAND) is a low-energy and low-background neutrino detector which could be a useful probe for determining the U and Th abundances of the Earth. We constructed a model of the Earth in order to evaluate the rate of geologically produced anti-neutrinos (geo-neutrinos) detectable by KamLAND. We found that KamLAND can be used to determine the absolute abundances of U and Th in the Earth with an accuracy sufficient for placing important constraints on Earth's accretional process and succeeding thermal history. The present observation of geo-neutrinos with KamLAND is consistent with our model prediction based on the bulk silicate Earth (BSE) composition within the uncertainty of the measurement. If a neutrino detector were to be built in Hawaii, where effects of the continental crust would be negligible, it could be used to estimate the U and Th content in the lower mantle and the core. Our calculation of the geo-neutrino event rate on the Earth's surface ind...

  19. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20132231 Chen Li(State Key Laboratory of Marine Geology,Tongji University,Shanghai200092,China);Xue Mei Group Velocity Tomography of Rayleigh Waves in South China Sea and Its Geodynamic Implications(Acta Seismologica Sinica,ISSN0253-3782,CN11-2021/P,34(6),2012,p.754-772,9illus.,46refs.,with English abstract)Key words:Rayleigh waves,velocity structure,South China Sea

  20. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102191 Du Letian(Beijing Uranium Geology Research Institute,Beijing 100029,China)Mantle Ichor(HACONS Fluids):The Interior Crucial Factor of Geodynamics(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,30(6),2009,p.739-748,7 illus.,2 tables,36 refs.)Key words:mantle convection,ore-forming fluidsThis paper attempts to summarize the achievements in geodynamic studies as a whole.Five dynamic principles of the Earth are put forward in this paper:1)the introduction of Na and K to any kind of rocks is the key to magma genesis;2)Na-and K-metasomatism is the most fundamental mechanism in whole hydrothermalism;3)geotectonic movement results from mantle-crust asthenospherization,which is stimulated by Na-and K-metasomatism;4)the evolution of the Earth is represented;and 5)Na-and K-fluids(namely,mantle ichors-HACONS)are derived from deep hydrogen(H+,H,H2)flow extraction from the mantle.20102192 Gao Rui(Lithosphere Research Center,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)

  1. Studies in geophysics: Active tectonics

    Science.gov (United States)

    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.

  2. MANIFESTATION OF FAULT ZONES IN GEOPHYSICAL FIELDS

    Directory of Open Access Journals (Sweden)

    A. A. Spivak

    2015-09-01

    Full Text Available Geophysical fields influenced by tectonics faults were observed, and instrumental observation results are analysed in the article. It is shown that fault zones are characterized by geophysical fields that are more variable than those in midmost segments of crustal blocks, more intense responses to weak external impacts such as lunar and solar tides and atmospheric pressure variations, and intensive relaxation. Transformation of energy between geophysical fields varying in origin takes place mainly in the fault zones.

  3. Institute of Geophysics, Planetary Physics, and Signatures

    Data.gov (United States)

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

  4. Lectures on Geophysical Fluid Dynamics

    Science.gov (United States)

    Samelson, Roger M.

    The fluid kaleidoscope of the Earth's ocean and atmosphere churns and sparkles with jets, gyres, eddies, waves, streams, and cyclones. These vast circulations, essential elements of the physical environment that support human life, are given a special character by the Earth's rotation and by their confinement to a shallow surficial layer, thin relative to the solid Earth in roughly the same proportion as an apple skin is to an apple. Geophysical fluid dynamics exploits this special character to develop a unified theoretical approach to the physics of the ocean and atmosphere.With Lectures on Geophysical Fluid Dynamics, Rick Salmon has added an insightful and provocative volume to the handful of authoritative texts currently available on the subject. The book is intended for first-year graduate students, but advanced students and researchers also will find it useful. It is divided into seven chapters, the first four of these adapted from course lectures. The book is well written and presents a fresh and stimulating perspective that complements existing texts. It would serve equally well either as the main text for a core graduate curriculum or as a supplementary resource for students and teachers seeking new approaches to both classical and contemporary problems. A lively set of footnotes contains many references to very recent work. The printing is attractive, the binding is of high quality, and typographical errors are few.

  5. SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    RUCKER DF; MYERS DA

    2011-10-04

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

  6. Open Access to Geophysical Data

    Science.gov (United States)

    Sergeyeva, Nataliya A.; Zabarinskaya, Ludmila P.

    2017-04-01

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

  7. Geophysical characterization of subsurface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Borns, D.J.

    1995-08-01

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

  8. GIPP: Geophysical Instrument Pool Potsdam

    Directory of Open Access Journals (Sweden)

    Christian Haberland

    2016-04-01

    Full Text Available The Geophysical Instrument Pool Potsdam (GIPP consists of field instruments, sensors and equipment for temporary seismological studies (both controlled source and earthquake seismology as well as for magnetotelluric (electromagnetic experiments. These instruments are mainly mobile digital recorders, broadband seis­mometers and short period sensors, and they are used to reveal the subsurface structure and to investigate earth­quakes. Sensors for magnetotellurics include induction coil and fluxgate magnetometers and non-polarizing silver / silver-chloride electrodes. It is operated by the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences. The instru­ment facility is open to all academic applicants, both national and international. Instrument applications are evalu­ated and ranked by an external steering board. Currently, for seismological applications >850 geophysical recorders, >170 broadband seis­mo­meters and >1300 short period geophones are available (among others. Available for magnetotelluric experiments are > 50 real-time data-loggers, >150 induction coils, and >500 electrodes. User guidelines and data policy are in force and data archives are provided (standard exchange formats.

  9. Agricultural Geophysics: Past, present, and future

    Science.gov (United States)

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

  10. Numerical simulation in applied geophysics

    CERN Document Server

    Santos, Juan Enrique

    2016-01-01

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

  11. Fractals in geology and geophysics

    Science.gov (United States)

    Turcotte, Donald L.

    1989-01-01

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

  12. Strainmeters and tiltmeters in geophysics

    Science.gov (United States)

    Goulty, N. R.

    1976-01-01

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

  13. Goddard Geophysical and Astronomical Observatory

    Science.gov (United States)

    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.

  14. Online Polar Oceans Geophysical Databases

    Science.gov (United States)

    Goodwillie, A. M.; O'Hara, S.; Arko, R. A.; Carbotte, S. M.

    2006-12-01

    With funding from the Office of Polar Programs of the U.S. National Science Foundation, the Antarctic Multibeam Bathymetry Synthesis (AMBS, http://www.marine-geo.org/antarctic/) is an integrated web-accessible bathymetry and geophysical database for the Southern Ocean and Antarctica, serving data from the US research vessels Nathaniel B. Palmer and Laurence M. Gould, amongst others. Interdisciplinary polar data can be downloaded for free through Data Link (http://www.marine-geo.org/link/index.php) which enables keyword searches by data and instrument type, geographical bounds, scientist, expedition name and dates. The data visualisation tool GeoMapApp (http://www.marine-geo.org/geomapapp/) supports dynamic exploration of a multi-resolutional digital elevation model (DEM) of the global oceans, including the polar regions, allowing users to generate custom grids and maps and import their own data sets and grids. A specialised polar stereographic map projection incorporating multibeam swath bathymetry and the BEDMAP under-ice seaflooor topography is available for the Southern Ocean. To promote inter-operability, we are working with research partners including the Marine Metadata Interoperability (MMI) project and the National Geophysical Data Center to develop standardised metadata and best practices that comply with existing FGDC and ISO standards. For example, the global DEM is served freely as an OGC-compliant Web Map Service map layer and is available for viewing with Google Earth. We are working towards full indexing of the AMBS database holdings at the Antarctic Master Directory. geo.org/antarctic/

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

    Science.gov (United States)

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

  16. EDITORIAL: The interface between geophysics and engineering

    Science.gov (United States)

    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

  17. Geotechnical applications of geophysics in coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Hatherly, P. [CMTE/CSIRO Exploration and Mining, North Ryde, NSW (Australia)

    2002-07-01

    In coal mining, geophysical techniques have an established application in determining the location of seam boundaries ahead of the face so that underground mines can be planned to avoid any geological structures that might disrupt production. Geophysics can also be used in geotechnical studies to determine the in situ properties of the rock mass and the response of the rock mass to the mining. The use of geophysical logs and microseismic monitoring in these geotechnical applications are discussed in this paper. 16 refs., 4 figs.

  18. Nonlinear regularization with applications in geophysics

    DEFF Research Database (Denmark)

    Berglund, Eva Ann-Charlotte

    2002-01-01

    integral equation, as well as for solving the two geophysical inverse problems considered in this thesis. We compare the IRGN method, the Levenberg-Marquardt method, the trust-region method and the inexact Gauss-Newton method for solving the nonlinear Hammerstein integral equation, and for solving two...... geophysical inverse problems: a seismic tomography problem, and a geoelectrical sounding problem. We found that all four methods gave reasonable solutions for the two geophysical problem. However, the inexact Gauss-Newton method converged faster than the others for the seismic tomography problem...

  19. Nonlinear regularization with applications in geophysics

    DEFF Research Database (Denmark)

    Berglund, Eva Ann-Charlotte

    2002-01-01

    integral equation, as well as for solving the two geophysical inverse problems considered in this thesis. We compare the IRGN method, the Levenberg-Marquardt method, the trust-region method and the inexact Gauss-Newton method for solving the nonlinear Hammerstein integral equation, and for solving two...... geophysical inverse problems: a seismic tomography problem, and a geoelectrical sounding problem. We found that all four methods gave reasonable solutions for the two geophysical problem. However, the inexact Gauss-Newton method converged faster than the others for the seismic tomography problem...

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

    Science.gov (United States)

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

    2005-05-01

    A unique characteristic of archaeological geophysics is to present the researchers in applied geophysics with the opportunity to verify their interpretation of geophysical data through the direct observation of often extremely detailed excavations. This is usually known as archaeological feedback. Archaeological materials have been slowly buried over periods ranging from several hundreds to several thousands of years, undergoing natural sedimentary and soil-forming processes. Once excavated, archaeological features therefore constitute more realistic test subjects than the targets artifically buried in common geophysical test sites. We are presenting the outcome of several such verification tests aimed at clarifying issues in geometry and spatial resolution of ground penetrating radar (GPR) images. On the site of a Roman villa in SE Portugal 500 Mhz GPR images are shown to depict very accurately the position and geometry of partially excavated remains. In the Maya city of Palenque, Mexico, 900 Mhz data allows the depth of tombs and natural cavities to be determined with cm accuracy. The predicted lateral extent of the cavities is more difficult to match with the reality due to the cluttering caused by high frequency. In the rainforest of Western Africa, 500 MHz GPR was used to prospect for stone tool sites. When very careful positioning and high density data sampling is achieved, stones can be accurately located and retrieved at depths exceeding 1 m with maximum positioning errors of 12cm horizontally and 2 cm vertically. In more difficult data collection conditions however, errors in positioning are shown to actually largely exceed the predictions based on quantitative theoretical resolution considerations. Geophysics has long been recognized as a powerful tool for prospecting and characterizing archaeological sites. Reciprocally, these results show that archaeology is an unparalleled test environment for the assesment and development of high resolution

  1. Fundamentals of Geophysical Fluid Dynamics

    Science.gov (United States)

    McWilliams, James C.

    2006-07-01

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

  2. Geophysical exploration in environmental engineering; Kankyo engineering ni okeru butsuri tansa

    Energy Technology Data Exchange (ETDEWEB)

    Shima, H. [OYO Corp., Tokyo (Japan)

    1997-12-01

    This paper describes underground environmental issues to which geophysical exploration can be applied. Especially, ground pollution, waste treatment and unexploded ordnance (mine) detection are discussed by considering worldwide technology trends through examples in Japan and the USA. Since environmental surveys are generally conducted for regional and rather shallow ground, rapidity, economy and high resolution are required for geophysical exploration. In response to these demands, a mapping system using capacitor electrodes and a complex resistivity method for detecting organic compounds are promising for the electrical prospecting. A shallow electromagnetic method is being standardized for the electromagnetic prospecting. A cesium magnetic gradient meter is also being standardized for the magnetic prospecting. An underground radar, seismic prospecting, and gravitational prospecting are also applied to some grounds. Prospecting of pollution sources, high- and low-concentration ground pollution, monitoring of pollutant removal, soundness survey of water barrier in management-type waste treatment place, and detection of unexploded ordnance are illustrated for the examples. 15 refs., 10 figs., 4 tabs.

  3. COLLADA Computing for Geophysical Applications Project

    Data.gov (United States)

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

  4. A geological and geophysical data collection system

    Digital Repository Service at National Institute of Oceanography (India)

    Sudhakar, T.; Afzulpurkar, S.

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

  5. Exploring the oceans- The geophysical way

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.

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

  6. The Geophysical Database Management System in Taiwan

    Directory of Open Access Journals (Sweden)

    Tzay-Chyn Shin

    2013-01-01

    Full Text Available The Geophysical Database Management System (GDMS is an integrated and web-based open data service which has been developed by the Central Weather Bureau (CWB, Taiwan, ROC since 2005. This service went online on August 1, 2008. The GDMS provides six types of geophysical data acquired from the Short-period Seismographic System, Broadband Seismographic System, Free-field Strong-motion Station, Strong-motion Building Array, Global Positioning System, and Groundwater Observation System. When utilizing the GDMS website, users can download seismic event data and continuous geophysical data. At present, many researchers have accessed this public platform to obtain geophysical data. Clearly, the establishment of GDMS is a significant improvement in data sorting for interested researchers.

  7. Physicist + Geologist points to Geophysics Course

    Science.gov (United States)

    Julian, Glenn M.; Stueber, Alan M.

    1974-01-01

    A two-quarter introductory course in geophysics at the advanced undergraduate/beginning graduate level is described. An outline of course content is provided, and mechanics of instruction are discussed. (DT)

  8. Air Force Geophysics Laboratory Magnetometer Network

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This file is comprised of the variation one minute values of the geomagnetic components X, Y and Z. These data were calculated by the Air Force Geophysics Laboratory...

  9. A field guide to geophysics in archaeology

    CERN Document Server

    Oswin, John

    2009-01-01

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

  10. Tabletop Models for Electrical and Electromagnetic Geophysics.

    Science.gov (United States)

    Young, Charles T.

    2002-01-01

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

  11. Marine geophysical data management and presentation system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.

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

  12. The remote sensing needs of Arctic geophysics

    Science.gov (United States)

    Campbell, W. J.

    1970-01-01

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

  13. Multiscale geophysical imaging of the critical zone

    Science.gov (United States)

    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.

  14. Brief Introduction of Sichuan Geophysical Company

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Founded in 1956,Sichuan Geophysicai Company (SCGC) is the largest engineering technological service enterprise for petroleum and natural gas seismic exploration in the westem part of China,which is integrated in acquisition,processing and interpretation of seismic data as well as technological deyelopment. Iris also a member of International Asociation of Geophysical Contractors, a member of Association of CNPC Geophysical Contractors and a survey unit with qualification of A level authenticated by China National Survey & Mapping Bureau.

  15. Dictionary of geophysics, astrophysics, and astronomy

    CERN Document Server

    Matzner, Richard A

    2001-01-01

    The Dictionary of Geophysics, Astrophysics, and Astronomy provides a lexicon of terminology covering fields such as astronomy, astrophysics, cosmology, relativity, geophysics, meteorology, Newtonian physics, and oceanography. Authors and editors often assume - incorrectly - that readers are familiar with all the terms in professional literature. With over 4,000 definitions and 50 contributing authors, this unique comprehensive dictionary helps scientists to use terminology correctly and to understand papers, articles, and books in which physics-related terms appear.

  16. Non-Seismic Geophysical Approaches to Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hoversten, G.M.; Gasperikova, Erika

    2004-09-01

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

  17. Geophysical applications for levee assessment

    Science.gov (United States)

    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

  18. Geophysical observations at cavity collapse

    Science.gov (United States)

    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.

  19. Geophysics of Small Planetary Bodies

    Science.gov (United States)

    Asphaug, Erik I.

    1998-01-01

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

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

    Science.gov (United States)

    Eppelbaum, L. V.

    2009-04-01

    . Application of multifocusing seismic processing to the GPR data analysis. Proceed. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems, Hyatt Regency Crystal City, Arlington, USA, 597-606. Borradaile, G. J., 2003. Viscous magnetization, archaeology and Bayesian statistics of small samples from Israel and England. Geophysical Research Letters, 30 (10), 1528, doi:10.1029/2003GL016977. Boyce, J.I., Reinhardt, E.G., Raban, A., and Pozza, M.R., 2004. The utility of marine magnetic surveying for mapping buried hydraulic concrete harbour structures: Marine Magnetic Survey of a Submerged Roman Harbour, Caesarea Maritima, Israel. The International Journal of Nautical Archaeology, 33, 1, 122-136. Bruins, H.J., van der Plicht, J., and Mazar, A., 2003. 14C dates from Tel-Rehov: Iron-age chronology, Pharaohs and Hebrew kings. Science, 300, 315-318. Daniels, J., Blumberg, D.J., Vulfson, L.D., Kotlyar, A.L., Freiliker, V., Ronen, G., and Ben-Asher, J., 2003. Microwave remote sensing of physically buried objects in the Negev Desert: implications for environmental research. Remote Sensing of Environment, 86, 243-256, 2003. Dolphin, L.T., 1981. Geophysical methods for archaeological surveys in Israel. Stanford Research International, Menlo Park, Calif., USA, 7 pp. Ellenblum, R., Marco, M., Agnon, A., Rockwell, T., and Boas, A., 1998. Crusader castle torn apart by earthquake at dawn, 20 May 1202. Geology, 26, No. 4, 303-306. 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., 2000a. Detailed geophysical investigations at archaeological sites. In: (Ed. A. Nissenbaum), Relation between archaeology and other scientific disciplines, Collection of Papers, Weitzman Inst., Rehovot, Israel, No.8, 39-54 (in Hebrew). Eppelbaum, L.V., 2000b. Applicability of geophysical methods for

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    Eppelbaum, Lev

    2017-04-01

    , apatite-nepheline, essentially sphalerite, and ore-quartz deposits of gold, tin, tungsten, molybdenum, zinc, crystal, and other raw materials. This method also enables differentiation of rocks such as bauxites, kimberlites, etc., from the host rocks, by their electrokinetic properties. Classification of some rocks, ores, and minerals by their piezoactivity is given in Table 1. These objects (targets) transform wave elastic oscillations into electromagnetic ones. It should be taken into account that anomalous bodies may be detected not only by positive, but also by negative anomalies, if low-piezoactive body occurs in the higher piezoactive medium. The piezoelectric method is an example of successful application of piezoelectric and seismo-electrokinetic phenomena in exploration and environmental geophysics and designed for delineation of targets differing from the host media by piezoelectric properties (Neishtadt et al., 2006, Neishtadt and Eppelbaum, 2012). This method is employed in surface, downhole, and underground modes. Recent testing of piezeoelectric effects of archaeological samples composed from fired clay have shown values of 2.0 - 3.0 ṡ 10-14 C/N. However, absence of reliable procedures for solving the direct and inverse problems of piezoelectric anomalies (PEA), drastically hampers further progression of the method. Therefore, it was suggested to adapt the tomography procedure, widely used in the seismic prospecting, to the PEA modeling. Diffraction of seismic waves has been computed for models of circular cylinder, thin inclined bed and thick bed (Alperovich et al., 1997). As a result, spatial-time distribution of the electromagnetic field caused by the seismic wave has been found. The computations have shown that effectiveness and reliability of PEA analysis may be critically enhanced by considering total electro- and magnetograms as differentiated from the conventional approaches. Distribution of the electromagnetic field obtained by solving the direct

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

    Science.gov (United States)

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

    2017-04-01

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

  4. Geophysics: creativity and the archaeological imagination

    Directory of Open Access Journals (Sweden)

    Rose Ferraby

    2017-06-01

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

  5. Introduction to Rheology and Application to Geophysics

    Science.gov (United States)

    Ancey, C.

    This chapter gives an overview of the major current issues in rheology through a series of different problems of particular relevance to geophysics. For each topic considered here, we will outline the key elements and point the reader to ward the most helpful references and authoritative works. The reader is also referred to available books introducing rheology [1, 2] for a more complete presentation and to the tutorial written by Middleton and Wilcock on mechanical and rheological app lications in geophysics [3]. This chapter will focus on materials encountered by geophysicists (mud, snow, magma, etc.), although in most cases we will consider only suspensions of particles within an interstitial fluid without loss of generality. Other complex fluids such as polymeric liquids are rarely encountered in geophysics.

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

    CERN Document Server

    Smerd, S F

    1969-01-01

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

  7. Digital geologic and geophysical data of Bangladesh

    Science.gov (United States)

    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.

  8. Geophysical tomography in engineering geology: an overview

    CERN Document Server

    Patella, D

    2005-01-01

    An overview of the tomographic interpretation method in engineering geophysics is presented, considering the two approaches of the deterministic tomography inversion, developed for rock elasticity analysis, and the probability tomography imaging developed in the domain of potential fields methods. The theoretical basis of both approaches is shortly outlined before showing a laboratory and a field application.

  9. Geophysical data fusion for subsurface imaging

    Science.gov (United States)

    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.

  10. Geophysical subsurface imaging for ecological applications.

    Science.gov (United States)

    Jayawickreme, Dushmantha H; Jobbágy, Esteban G; Jackson, Robert B

    2014-03-01

    Ecologists, ecohydrologists, and biogeochemists need detailed insights into belowground properties and processes, including changes in water, salts, and other elements that can influence ecosystem productivity and functioning. Relying on traditional sampling and observation techniques for such insights can be costly, time consuming, and infeasible, especially if the spatial scales involved are large. Geophysical imaging provides an alternative or complement to traditional methods to gather subsurface variables across time and space. In this paper, we review aspects of geophysical imaging, particularly electrical and electromagnetic imaging, that may benefit ecologists seeking clearer understanding of the shallow subsurface. Using electrical resistivity imaging, for example, we have been able to successfully show the effect of land-use conversions to agriculture on salt mobilization and leaching across kilometer-long transects and to depths of tens of meters. Recent advances in ground-penetrating radar and other geophysical imaging methods currently provide opportunities for subsurface imaging with sufficient detail to locate small (≥5 cm diameter) animal burrows and plant roots, observe soil-water and vegetation spatial correlations in small watersheds, estuaries, and marshes, and quantify changes in groundwater storage at local to regional scales using geophysical data from ground- and space-based platforms. Ecologists should benefit from adopting these minimally invasive, scalable imaging technologies to explore the subsurface and advance our collective research.

  11. Predictability of extreme values in geophysical models

    NARCIS (Netherlands)

    Sterk, A.E.; Holland, M.P.; Rabassa, P.; Broer, H.W.; Vitolo, R.

    2012-01-01

    Extreme value theory in deterministic systems is concerned with unlikely large (or small) values of an observable evaluated along evolutions of the system. In this paper we study the finite-time predictability of extreme values, such as convection, energy, and wind speeds, in three geophysical model

  12. Geophysical investigations in the territory of Bolgar state historical and architectural museum-reserve in 2014

    Directory of Open Access Journals (Sweden)

    Brednikov Konstantin I.

    2015-09-01

    Full Text Available The results of geophysical investigations which was carried out in 2014 in the territory of Bolgar State Historical and Architectural Museum-Reserve are reviewed in the article. Territory of Bolgar State Historical and Architectural Museum-Reserve is part of the UNESCO protected sites. The set of works included wide range of geophysical investigations: magnetometry, gravimetry, electrical prospecting and georadar. The main goal of investigations was detecting and localization of archaeological objects remnant (houses, mausoleums, kilns, etc.. Magnetometry was the basic method during carrying out the works. Magnetic measurements are used in the practice of archaeological investigations very widely due to the high informativeness and productiveness of this method. The major search objects are the brick bases and building walls, accumulation of fired ceramic, the remnants of furnace construction for various purposes. Georadar survey, gravity and electrical prospecting were used for localization of nonmagnetic objects. It is identified a line of objects differing in its properties and purpose as a result of research. There are furnaces, mausoleum bases, remains of domestic buildings. Methodology for conducting of field experiments has been refined and optimized in the process of carrying out of geophysical investigations.

  13. New airborne geophysical data from the Waterberg Coalfield

    CSIR Research Space (South Africa)

    Fourie, CJS

    2009-07-01

    Full Text Available in 1920, but little exploration has been done since. Coaltech Research Association commissioned an Airborne Geophysical Survey of the area to enhance the structural understanding of the basin. The airborne geophysical survey was a major contribution...

  14. Geophysics applications in critical zone science: emerging topics

    Science.gov (United States)

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

  15. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    Science.gov (United States)

    Abbas, M.; Jardani, A.

    2015-12-01

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

  16. Geophysical monitoring in a hydrocarbon reservoir

    Science.gov (United States)

    Caffagni, Enrico; Bokelmann, Goetz

    2016-04-01

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

  17. Informing groundwater models with near-surface geophysical data

    DEFF Research Database (Denmark)

    Herckenrath, Daan

    of the geophysical data. The CHI-S yielded a geophysical model that could never be obtained with a separate geophysical inversion. Furthermore, we applied a CHI-S to evaluate the potential for time-lapse relative gravimetry (TL-RG) and magnetic resonance sounding (TL-MRS) to improve the estimation of aquifer...

  18. Ninety Years of International Cooperation in Geophysics

    Science.gov (United States)

    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

  19. COMPARISON OF FOURIER AND WAVELET TRANSFORMS IN GEOPHYSICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Hakan ALP

    2008-01-01

    Full Text Available In this study, it was compared Fourier Transformation using widely in analysing of geophysics data and image processing and Wavelet Transformation using in image processing, boundary analysis and recently years in use geophysical data analysis. It was applicated and compared two transformations in the both geophysical data and fundamental functions. Then the results obtained were evaluated. In this study it was compared two transformation using earthquake records and Bouger gravity anomalies map of Hatay region geophysical data. At the end of the our study it was clearly seen that wavelet transform can be used by geophysical data analysing.

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

    Energy Technology Data Exchange (ETDEWEB)

    GV Last; DG Horton

    2000-03-23

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

  1. The geophysical impact of the Aristoteles mission

    Science.gov (United States)

    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.

  2. Geophysical and atmospheric evolution of habitable planets.

    Science.gov (United States)

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

    2010-01-01

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

  3. The INCA International Course on ArchaeoGeophysics - an EU intensive program of teaching interdisciplinarity in science

    Science.gov (United States)

    Rabbel, Wolfgang; Baris, Serif; Pasteka, Roman

    2010-05-01

    As part of the European Union ERASMUS program the Universities of Kiel, Kocaeli and Bratislava have set up an international summer school on archaeological prospecting with geophysical methods. The general aims of the course are to improve interdisciplinary understanding between natural and philosophical sciences, represented by geophysics and archaeology, to teach state-of-the-art science and to apply this knowledge in real-world situations at the same time, to practice driving and presenting scientific results, and -last but not least - to improve the understanding between different cultures. The first field courses were held near the cities of Iznik, Turkey, and Nitra, Slovakia. Iznik isr the ancient city of Nicea located close to the Marmara Sea and the North Anatolian Fault Zone. Nitra is situated in western Slovakia close to the "Slovakian Gate", a major geographical pathway to mining districts of bronze age in the Carpathian Mountains. The course schedule comprises an introduction to the regional and local situation from archaeological and geologic-tectonic points of view situation, methodical lectures and practical field work with state-of-the art geophysical instruments (geomagnetics, geoelectrics, ground penetrating radar, micro-gravimetry). In-door course work comprises digital data processing and interpretationswell as presenting results to students, local authorities and the public. Course participants are ca. 35 students of Archaeology and Geophysics. In cooperation with the local authorities sites were selected in order to demonstrate the different potential and requirements of geophysical prospection in archaeology. The sites comprised urban areas as wells as sites on the countryside, such as the prospecting of future construction ground, ancient and recent water supply systems, pre-historic settlement hills, and geological features. The field examples demonstrated the advantages, and often the need, to apply different exploration methods in order

  4. Development of geophysical data management system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tai-Sup; Lee, Sang-Kyu; Gu, Sung-Bon [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

    1999-12-01

    (1) Development of a complete geophysical database system under C/S environment for data management. (2) Development of database system for the general user, who has not special knowledge of database, under the Internet environment. (3) Operation of the Web service for the general user. (4) Development of the stand-alone database system for a small-scale research group such as college and engineering consultant firms. (author). 15 refs.

  5. FY97 Geophysics Technology Area Plan.

    Science.gov (United States)

    1997-03-01

    Under the High-frequency Active Auroral Research drag and to provide accurate winds and composition Program ( HAARP ), research was initiated to assess...Satellite Communications FY Fiscal Year GP Geophysics GPS Global Positioning System HAARP High Frequency Active Auroral Research Program BF High...and Combat Operations 3,14 Global Positioning System (GPS) ii,5,6,8,9,12,17 High Frequency Active Auroral Research Program ( HAARP ) 8,11 Industrial

  6. Geophysical, geological, environmental and technical program guidelines

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    The Canada-Newfoundland Offshore Petroleum Board has created a set of guidelines which describe the information needed by the Board for authorizations relating to geophysical, geological, environmental or geotechnical programs. The guidelines also describe the review process that will be followed in considering a proponent`s application. Since these guidelines are subordinate to the Canada-Newfoundland Atlantic Accord Implementation Act and the Canada-Newfoundland Atlantic Accord Implementation (Newfoundland) Act, proponents must refer to both in preparing their development applications.

  7. Application of geophysical methods for fracture characterization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.H.; Majer, E.L. [Lawrence Berkeley Lab., CA (USA); McEvilly, T.V. [Lawrence Berkeley Lab., CA (USA)]|[California Univ., Berkeley, CA (USA). Dept. of Geology and Geophysics; Morrison, H.F. [Lawrence Berkeley Lab., CA (USA)]|[California Univ., Berkeley, CA (USA). Dept. of Materials Science and Mineral Engineering

    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.

  8. Time-lapse geophysical technology-based study on overburden strata changes induced by modern coal mining

    Institute of Scientific and Technical Information of China (English)

    Wenfeng Du; Suping Peng; Guowei Zhu; Feng Yang

    2014-01-01

    To study the impact of modern coal mining on overlying strata and its water bearing conditions, integrated time-lapse geophysical prospecting integrating 3D seismic, electrical and ground penetrating radar method were used. Through observing and analyzing the geophysical data variations of all stages of pre-mining, mining and post-mining as well as post-mining deposition stable period, impacts of coal mining on stratigraphic structure and its water bearing were studied and modern coal mining induced stratigraphic change pattern was summarized. The research result shows that the stratigraphic structure and the water bearing of surface layer during modern coal mining have self-healing pattern with mining time;the self-healing capability of near-surface strata is relatively strong while the roof weak;water bearing self-healing of near-surface strata is relatively high while the roof strata adjacent to mined coal beds low. Due to integrated time-lapse geophysical prospecting technology has extra time dimension which makes up the deficiency of static analysis of conventional geophysical methods, it can better highlight the dynamic changes of modern coal mining induced over-burden strata and its water bearing conditions.

  9. Mass Transport in Global Geophysical Fluids

    Science.gov (United States)

    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.

  10. Mathematical Methods for Geophysics and Space Physics

    Science.gov (United States)

    Newman, William I.

    2016-05-01

    Graduate students in the natural sciences - including not only geophysics and space physics but also atmospheric and planetary physics, ocean sciences, and astronomy - need a broad-based mathematical toolbox to facilitate their research. In addition, they need to survey a wider array of mathematical methods that, while outside their particular areas of expertise, are important in related ones. While it is unrealistic to expect them to develop an encyclopedic knowledge of all the methods that are out there, they need to know how and where to obtain reliable and effective insights into these broader areas. Here at last is a graduate textbook that provides these students with the mathematical skills they need to succeed in today's highly interdisciplinary research environment. This authoritative and accessible book covers everything from the elements of vector and tensor analysis to ordinary differential equations, special functions, and chaos and fractals. Other topics include integral transforms, complex analysis, and inverse theory; partial differential equations of mathematical geophysics; probability, statistics, and computational methods; and much more. Proven in the classroom, Mathematical Methods for Geophysics and Space Physics features numerous exercises throughout as well as suggestions for further reading. * Provides an authoritative and accessible introduction to the subject * Covers vector and tensor analysis, ordinary differential equations, integrals and approximations, Fourier transforms, diffusion and dispersion, sound waves and perturbation theory, randomness in data, and a host of other topics * Features numerous exercises throughout * Ideal for students and researchers alike * An online illustration package is available to professors

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

    Science.gov (United States)

    Vallis, Geoffrey K.

    2016-08-01

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

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

    Science.gov (United States)

    Eppelbaum, Lev

    2010-05-01

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

  13. Geophysical Hunt for Chromite in Ophiolite

    Directory of Open Access Journals (Sweden)

    Mubarik Ali

    2013-12-01

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

  14. Applications of geophysical methods to volcano monitoring

    Science.gov (United States)

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

    2006-01-01

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

  15. A fractured rock geophysical toolbox method selection tool

    Science.gov (United States)

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

    2016-01-01

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

  16. The Expanding Marketplace for Applied Geophysics

    Science.gov (United States)

    Carlson, N.; Sirles, P.

    2012-12-01

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

  17. Effect of regularization parameters on geophysical reconstruction

    Institute of Scientific and Technical Information of China (English)

    Zhou Hui; Wang Zhaolei; Qiu Dongling; Li Guofa; Shen Jinsong

    2009-01-01

    In this paper we discuss the edge-preserving regularization method in the reconstruction of physical parameters from geophysical data such as seismic and ground-penetrating radar data.In the regularization method a potential function of model parameters and its corresponding functions are introduced.This method is stable and able to preserve boundaries, and protect resolution.The effect of regularization depends to a great extent on the suitable choice of regularization parameters.The influence of the edge-preserving parameters on the reconstruction results is investigated and the relationship between the regularization parameters and the error of data is described.

  18. Predictability of extreme values in geophysical models

    Directory of Open Access Journals (Sweden)

    A. E. Sterk

    2012-09-01

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

  19. Large natural geophysical events: planetary planning

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-09-01

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

  20. Artificial intelligence and dynamic systems for geophysical applications

    CERN Document Server

    Gvishiani, Alexei

    2002-01-01

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

  1. PROSPECTING EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20082879 Chen Yaoyu(No.3 Geology and Mineral Exploration Team,Gansu Provincial Bureau of Geology and Mineral Exploration and Development,Lanzhou 730050,China); Gong Quansheng Discussion on the Division of Deposit Scale and the Index of Ore Prospecting(Gansu Geology,ISSN 1004—4116,CN62—1191/P,16(3),2007,p.6—11,4 tables,6 refs.) Key words:prospecting and exploration of mineral

  2. Geophysical Characterization of Range-Front Faults, Snake Valley, Nevada

    Science.gov (United States)

    Asch, Theodore H.; Sweetkind, Donald S.

    2010-01-01

    In September 2009, the U.S. Geological Survey, in cooperation with the National Park Service, collected audiomagnetotelluric (AMT) data along two profiles on the eastern flank of the Snake Range near Great Basin National Park to refine understanding of the subsurface geology. Line 1 was collected along Baker Creek, was approximately 6.7-km long, and recorded subsurface geologic conditions to approximately 800-m deep. Line 2, collected farther to the southeast in the vicinity of Kious Spring, was 2.8-km long, and imaged to depths of approximately 600 m. The two AMT lines are similar in their electrical response and are interpreted to show generally similar subsurface geologic conditions. The geophysical response seen on both lines may be described by three general domains of electrical response: (1) a shallow (mostly less than 100-200-m deep) domain of highly variable resistivity, (2) a deep domain characterized by generally high resistivity that gradually declines eastward to lower resistivity with a steeply dipping grain or fabric, and (3) an eastern domain in which the resistivity character changes abruptly at all depths from that in the western domain. The shallow, highly variable domain is interpreted to be the result of a heterogeneous assemblage of Miocene conglomerate and incorporated megabreccia blocks overlying a shallowly eastward-dipping southern Snake Range detachment fault. The deep domain of generally higher resistivity is interpreted as Paleozoic sedimentary rocks (Pole Canyon limestone and Prospect Mountain Quartzite) and Mesozoic and Cenozoic plutonic rocks occurring beneath the detachment surface. The range of resistivity values within this deep domain may result from fracturing adjacent to the detachment, the presence of Paleozoic rock units of variable resistivities that do not crop out in the vicinity of the lines, or both. The eastern geophysical domain is interpreted to be a section of Miocene strata at depth, overlain by Quaternary alluvial

  3. Geophysical Analysis of BP`s Luva Discovery: 6707/10-1

    Energy Technology Data Exchange (ETDEWEB)

    Marten, Robert F.

    1998-12-31

    The Nyk High area of the Norwegian Sea is seen as a significant hydrocarbon opportunity. The area is situated in the Voering Basin I area, and lies in a water depth of 1200-1500 m. A 900 km{sup 2} 3-D seismic survey was acquired in 1996 and made the basis for the subsequent license and prospect evaluation.The 3-D confirmed the presence of a pronounced flat-spot in the main prospect which was named Luva. This presentation relates to the work which will present a comprehensive examination of both pre and post-drill geophysical analysis, with particular attention given to fluid phase prediction and the forward program. 6 figs.

  4. The Continental Crust: A Geophysical Approach

    Science.gov (United States)

    Christensen, Nikolas I.

    Nearly 80 years ago, Yugoslavian seismologist Andrija Mohorovicic recognized, while studying a Balkan earthquake, that velocities of seismic waves increase abruptly at a few tens of kilometers depth , giving rise to the seismological definition of the crust. Since that discovery, many studies concerned with the nature of both the continental and oceanic crusts have appeared in the geophysical literature.Recently, interest in the continental crust has cascaded. This is largely because of an infusion of new data obtained from major reflection programs such as the Consortium for Continental Reflection Profiling (COCORP) and British Institutions Reflection Profiling Syndicate (BIRPS) and increased resolution of refraction studies. In addition, deep continental drilling programs are n ow in fashion. The Continental Crust: A Geophysical Approach is a summary of present knowledge of the continental crust. Meissner has succeeded in writing a book suited to many different readers, from the interested undergraduate to the professional. The book is well documented , with pertinent figures and a complete and up-to-date reference list.

  5. Satellites provide new insights into polar geophysics

    Science.gov (United States)

    Laxon, Seymour; McAdoo, David

    A revolution in polar geophysics is under way thanks to altimeter data, which the ERS satellites have been collecting since 1991. Geophysical surveys in the polar regions have long been hampered by inaccessibility, particularly in areas that are covered yearround by sea ice or land ice. As a result the major remaining uncertainties in global tectonic models of the Mesozoic and Cenozoic tend to lie in the Arctic and Antarctic regions. In fact, major tectonic plate boundaries have been hypothesized, but not confirmed, for both regions. In the Arctic, a divergent plate boundary associated with the Mesozoic opening of the Canada Basin has been proposed [e.g., Lawver et al., 1990] while in the Antarctic a divergent boundary, active during the late Cretaceous in the Amundsen Sea, has been hypothesized [Cande et al., 1995; Stock and Molnar, 1987]. Due to the acute sparseness of seafloor surveys in these areas, however, no one has been able to prove that these plate boundaries actually existed, nor has anyone been able to locate extinct remnants of the boundaries. High-resolution marine gravity fields (Figures 1 and 2) derived from satellite altimeter data are now redressing this problem of sparse surveys.

  6. New perspectives on superparameterization for geophysical turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Majda, Andrew J. [Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States); Center for Prototype Climate Modelling, NYU Abu Dhabi, Abu Dhabi (United Arab Emirates); Grooms, Ian, E-mail: grooms@cims.nyu.edu [Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States)

    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.

  7. Geophysical limits to global wind power

    Science.gov (United States)

    Marvel, Kate; Kravitz, Ben; Caldeira, Ken

    2013-02-01

    There is enough power in Earth's winds to be a primary source of near-zero-emission electric power as the global economy continues to grow through the twenty-first century. Historically, wind turbines are placed on Earth's surface, but high-altitude winds are usually steadier and faster than near-surface winds, resulting in higher average power densities. Here, we use a climate model to estimate the amount of power that can be extracted from both surface and high-altitude winds, considering only geophysical limits. We find wind turbines placed on Earth's surface could extract kinetic energy at a rate of at least 400TW, whereas high-altitude wind power could extract more than 1,800TW. At these high rates of extraction, there are pronounced climatic consequences. However, we find that at the level of present global primary power demand (~ 18TW ref. ), uniformly distributed wind turbines are unlikely to substantially affect the Earth's climate. It is likely that wind power growth will be limited by economic or environmental factors, not global geophysical limits.

  8. Direct Statistical Simulation of Geophysical Flows

    Science.gov (United States)

    Marston, Brad; Chini, Greg; Tobias, Steve

    2015-11-01

    Statistics of models of geophysical and astrophysical fluids may be directly accessed by solving the equations of motion for the statistics themselves as proposed by Lorenz nearly 50 years ago. Motivated by the desire to capture seamlessly multiscale physics we introduce a new approach to such Direct Statistical Simulation (DSS) based upon separating eddies by length scale. Discarding triads that involve only small-scale waves, the equations of motion generalize the quasi-linear approximation (GQL) and are able to accurately reproduce the low-order statistics of a stochastically-driven barotropic jet. Furthermore the two-point statistics of high wavenumber modes close and thus generalize second-order cumulant expansions (CE2) that employ zonal averaging. This GCE2 approach is tested on two-layer primitive equations. Comparison to statistics accumulated from numerical simulation finds GCE2 to be quantitatively accurate. DSS thus leads to new insight into important processes in geophysical and astrophysical flows. Supported in part by NSF DMR-1306806 and NSF CCF-1048701.

  9. Spatial and temporal distribution of geophysical disasters

    Directory of Open Access Journals (Sweden)

    Cvetković Vladimir

    2013-01-01

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

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

    Science.gov (United States)

    McAdoo, B. G.

    2003-12-01

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

  11. Geophysical subsurface imaging and interface identification.

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-01

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

  12. Interactive Geophysical Mapping on the Web

    Science.gov (United States)

    Meertens, C.; Hamburger, M.; Estey, L.; Weingroff, M.; Deardorff, R.; Holt, W.

    2002-12-01

    We have developed a set of interactive, web-based map utilities that make geophysical results accessible to a large number and variety of users. These tools provide access to pre-determined map regions via a simple Html/JavaScript interface or to user-selectable areas using a Java interface to a Generic Mapping Tools (GMT) engine. Users can access a variety of maps, satellite images, and geophysical data at a range of spatial scales for the earth and other planets of the solar system. Developed initially by UNAVCO for study of global-scale geodynamic processes, users can choose from a variety of base maps (satellite mosaics, global topography, geoid, sea-floor age, strain rate and seismic hazard maps, and others) and can then add a number of geographic and geophysical overlays for example coastlines, political boundaries, rivers and lakes, NEIC earthquake and volcano locations, stress axes, and observed and model plate motion and deformation velocity vectors representing a compilation of 2933 geodetic measurements from around the world. The software design is flexible allowing for construction of special editions for different target audiences. Custom maps been implemented for UNAVCO as the "Jules Verne Voyager" and "Voyager Junior", for the International Lithosphere Project's "Global Strain Rate Map", and for EarthScope Education and Outreach as "EarthScope Voyager Jr.". For the later, a number of EarthScope-specific features have been added, including locations of proposed USArray (seismic), Plate Boundary Observatory (geodetic), and San Andreas Fault Observatory at Depth sites plus detailed maps and geographically referenced examples of EarthScope-related scientific investigations. In addition, we are developing a website that incorporates background materials and curricular activities that encourage users to explore Earth processes. A cluster of map processing computers and nearly a terabyte of disk storage has been assembled to power the generation of

  13. Educational Geophysics at INGV, Rome (Italy)

    Science.gov (United States)

    Dida Working Group Ingv,.

    2002-12-01

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

  14. 3D geophysical inversion for contact surfaces

    Science.gov (United States)

    Lelièvre, Peter; Farquharson, Colin

    2014-05-01

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

  15. PROSPECTING EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20092072 Guo Kuicheng(Heilongjiang Institute of Geological Survey,Qiqihar 161005,China);Ma Jianshui Multi-Source Data Integration Technique in Shallow Cover Areas(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,27(7),2008,p.1097-1102,3 illus.,2 tables,10 refs.)Key words:geologic mapping,digital cartographyThe multi-source data integration technique is a new technique developed on the basis of digital mapping.The work method is to process and integrate multi-source data,e.g.geological and mineral resource,geophysical and geochemical and remote sensing data,on computer and extract relevant geological information and integrate multi-source data with geological data to establish

  16. Geophysical modelling of 3D electromagnetic diffusion with multigrid

    NARCIS (Netherlands)

    Mulder, W.A.

    2008-01-01

    The performance of a multigrid solver for time-harmonic electromagnetic problems in geophysical settings was investigated. With the low frequencies used in geophysical surveys for deeper targets, the light-speed waves in the earth can be neglected. Diffusion of induced currents is the dominant physi

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  18. Application of geophysical methods to agriculture: An overview

    Science.gov (United States)

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

  19. Comparison study of selected geophysical and geotechnical parameters

    DEFF Research Database (Denmark)

    Nissen, Randi Warncke; Poulsen, Søren Erbs

    2015-01-01

    Successful foundation of constructions relies on accurate characterization of the geotechnical properties of the subsurface. By implementing data from geophysical surveys, the placement of geotechnical drillings can be significantly improved, potentially reducing the number of required drillings....... This case study is mainly to compare geophysical investigations (MEP/IP) with existing PACES data and information from geotechnical drillings....

  20. Introduction to the JEEG Agricultural Geophysics special issue

    Science.gov (United States)

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

  1. Numerical Inversion of Integral Equations for Medical Imaging and Geophysics

    Science.gov (United States)

    1988-12-13

    Equations for Medical Imaging and Geophysics (Unclassified) 12 PERSONAL AUTHOR(S) Frank Stenger 13a. TYPE OF REPORT 13b TIME COVERED 14. DATE OF REPORT...9r~S NUMERICAL INVERSION OF INTEGRAL EQUATIONS FOR MEDICAL IMAGING AND GEOPHYSICS FINAL REPORT AUTHOR OF REPORT: Frank Stenger December 13, 1988

  2. Geophysical couples” Discuss jobs, marriage

    Science.gov (United States)

    Some 90 participants attended an open forum, “Dual Career Couples: Challenges and Opportunities,” on December 9 at the AGU Fall 1991 Meeting in San Francisco. Several couples summarized their experiences in “geophysical marriages” while the audience contributed questions and comments.Being forced to live apart was a common complaint among the married panelists. One couple on the panel—Karen Prestegaard of the University of Maryland and Jim Luhr of the Smithsonian Institution's Department of Mineral Physics—have been able to live together only 2 years out of the last 10. Although employer guidelines do not officially prohibit hiring couples, Prestegaard and Luhr expressed frustration that many institutions not only will not do so, but also will not help the second partner find a job nearby.

  3. Avalanches in functional materials and geophysics

    CERN Document Server

    Saxena, Avadh; Planes, Antoni

    2017-01-01

    This book provides the state-of-the art of the present understanding of avalanche phenomena in both functional materials and geophysics. The main emphasis of the book is analyzing these apparently different problems within the common perspective of out-of-equilibrium phenomena displaying spatial and temporal complexity that occur in a broad range of scales. Many systems, when subjected to an external force, respond intermittently in the form of avalanches that often span over a wide range of sizes, energies and durations. This is often related to a class of critical behavior characterized by the absence of characteristic scales. Typical examples are magnetization processes, plastic deformation and failure occuring in functional materials. These phenomena share many similarities with seismicity arising from the earth crust failure due to stresses that originate from plate tectonics.

  4. A mixture theory for geophysical fluids

    Directory of Open Access Journals (Sweden)

    A. C. Eringen

    2004-01-01

    Full Text Available A continuum theory is developed for a geophysical fluid consisting of two species. Balance laws are given for the individual components of the mixture, modeled as micropolar viscous fluids. The continua allow independent rotational degrees of freedom, so that the fluids can exhibit couple stresses and a non-symmetric stress tensor. The second law of thermodynamics is used to develop constitutive equations. Linear constitutive equations are constituted for a heat conducting mixture, each species possessing separate viscosities. Field equations are obtained and boundary and initial conditions are stated. This theory is relevant to an atmospheric mixture consisting of any two species from rain, snow and/or sand. Also, this is a continuum theory for oceanic mixtures, such as water and silt, or water and oil spills, etc.

  5. Cosmic Muon Detection for Geophysical Applications

    Directory of Open Access Journals (Sweden)

    László Oláh

    2013-01-01

    Full Text Available A portable cosmic muon detector has been developed for environmental, geophysical, or industrial applications. The device is a tracking detector based on the Close Cathode Chamber, an MWPC-like technology, allowing operation in natural underground caves or artificial tunnels, far from laboratory conditions. The compact, low power consumption system with sensitive surface of 0.1 m2 measures the angular distribution of cosmic muons with a resolution of 10 mrad, allowing for a detailed mapping of the rock thickness above the muon detector. Demonstration of applicability of the muon telescope (REGARD Muontomograph for civil engineering and measurements in artificial underground tunnels or caverns are presented.

  6. The geology and geophysics of Mars

    Science.gov (United States)

    Saunders, R. S.

    1976-01-01

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

  7. Georadar - high resolution geophysical electromagnetic device

    Directory of Open Access Journals (Sweden)

    Janez Stern

    1995-12-01

    Full Text Available Georadar is a high resolution geophysical electromagnetic device that was developed in the first part of the 1980's. In Slovenia it was first tested in 1991 on several objects of economicgeological, geotechnical and hydrogeologic nature.Here its usefulness in karst studied is presented. The first part of the paper deals with description of measurement procedure and methodological bases, and the second part with experience and results of case histories. Shown are radargrams from ornamental stone quarry Hotavlje, calcite mine Stahovica, Golobja jama karstcave near Divača and from highway construction site Razdrto-Čebulovica. All measurements were performed with the georadar instrument Pulse EKKO IV with a lOOMHz antenna according to the method of reflection profiling.

  8. Problems of data bases in geophysics

    Science.gov (United States)

    Hartmann, G. K.

    Ten problems areas in the design and implementation of geophysical data bases are listed and briefly characterized. The emphasis is on software aspects, which are seen as critical given the current state of hardware technology. Topics examined include data sources and users; the difference between information-ordering schemes for the humanities and for the natural sciences; economic limitations on acquisition, evaluation, and storage of data; private versus public data; centralized, decentralized, and distributed computer systems; and the need for structured, transportable, and adequately documented software. A glossary of data terminology, extensive tables and block diagrams listing types of data and applications and illustrating ordering schemes, estimates of the data-processing and storage requirements of typical missions, and a summary of the CODMAC 1982 recommendations are provided.

  9. Software complex for geophysical data visualization

    Science.gov (United States)

    Kryukov, Ilya A.; Tyugin, Dmitry Y.; Kurkin, Andrey A.; Kurkina, Oxana E.

    2013-04-01

    The effectiveness of current research in geophysics is largely determined by the degree of implementation of the procedure of data processing and visualization with the use of modern information technology. Realistic and informative visualization of the results of three-dimensional modeling of geophysical processes contributes significantly into the naturalness of physical modeling and detailed view of the phenomena. The main difficulty in this case is to interpret the results of the calculations: it is necessary to be able to observe the various parameters of the three-dimensional models, build sections on different planes to evaluate certain characteristics and make a rapid assessment. Programs for interpretation and visualization of simulations are spread all over the world, for example, software systems such as ParaView, Golden Software Surfer, Voxler, Flow Vision and others. However, it is not always possible to solve the problem of visualization with the help of a single software package. Preprocessing, data transfer between the packages and setting up a uniform visualization style can turn into a long and routine work. In addition to this, sometimes special display modes for specific data are required and existing products tend to have more common features and are not always fully applicable to certain special cases. Rendering of dynamic data may require scripting languages that does not relieve the user from writing code. Therefore, the task was to develop a new and original software complex for the visualization of simulation results. Let us briefly list of the primary features that are developed. Software complex is a graphical application with a convenient and simple user interface that displays the results of the simulation. Complex is also able to interactively manage the image, resize the image without loss of quality, apply a two-dimensional and three-dimensional regular grid, set the coordinate axes with data labels and perform slice of data. The

  10. Applied Geophysics Opportunities in the Petroleum Industry

    Science.gov (United States)

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

    2012-12-01

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

  11. Online Geophysical Databases for the Southern Ocean

    Science.gov (United States)

    Goodwillie, A.; O'Hara, S.; Arko, R.; Carbotte, S.; Ryan, W.; Melkonian, A.; Ferrini, V.; Weissel, R.; Bonczkowski, J.

    2007-12-01

    With funding from the U.S. National Science Foundation Office of Polar Programs, the Antarctic Multibeam Bathymetry Synthesis (AMBS, http://www.marine-geo.org/antarctic/) is an integrated web-accessible bathymetry and geophysical database for the Southern Ocean and Antarctica, serving data from the US research vessels Nathaniel B. Palmer and Laurence M. Gould, amongst others. Interdisciplinary polar data can be downloaded for free through the Data Link web browser interface (http://www.marine-geo.org/link/) which enables keyword searches by data and instrument type, geographical bounds, scientist, expedition name and dates. The free, platform-independent data visualization tool GeoMapApp (http://www.geomapapp.org/) supports dynamic exploration of a wide range of data sets on a Global Multi-Resolution Topography (GMRT) synthesis, including the polar regions, allowing users to generate custom grids and maps and import their own data sets and grids. A specialised polar stereographic map projection incorporating multibeam swath bathymetry and the BEDMAP under-ice seafloor topography is available for the Southern Ocean. The GMRT global digital elevation model is served freely as a Web Map Service layer and is available for viewing with OGC-compliant clients including Google Earth (http://www.marine-geo.org/Data4GoogleEarth.html). To promote interoperability and data sharing, we are working with research partners including the Marine Metadata Interoperability (MMI) project and the National Geophysical Data Center to develop standardised metadata and best practices that comply with existing FGDC and ISO standards. We are also taking on the US Antarctic Data Coordination Center function, assisting NSF-funded investigators in documenting and archiving their data in accordance with the IPY Data Policy.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    Yalo Nicaise

    2012-01-01

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

  14. Biodiversity Prospecting.

    Science.gov (United States)

    Sittenfeld, Ana; Lovejoy, Annie

    1994-01-01

    Examines the use of biodiversity prospecting as a method for tropical countries to value biodiversity and contribute to conservation upkeep costs. Discusses the first agreement between a public interest organization and pharmaceutical company for the extraction of plant and animal materials in Costa Rica. (LZ)

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

    Science.gov (United States)

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

    2012-12-01

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

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

    Science.gov (United States)

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

    1994-04-01

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

  17. Prospecting for marine gas hydrate resources

    Science.gov (United States)

    Boswell, Ray; Shipp, Craig; Reichel, Thomas; Shelander, Dianna; Saeki, Tetsuo; Frye, Matthew; Shedd, William; Collett, Timothy S.; McConnell, Daniel R.

    2016-01-01

    As gas hydrate energy assessment matures worldwide, emphasis has evolved away from confirmation of the mere presence of gas hydrate to the more complex issue of prospecting for those specific accumulations that are viable resource targets. Gas hydrate exploration now integrates the unique pressure and temperature preconditions for gas hydrate occurrence with those concepts and practices that are the basis for conventional oil and gas exploration. We have aimed to assimilate the lessons learned to date in global gas hydrate exploration to outline a generalized prospecting approach as follows: (1) use existing well and geophysical data to delineate the gas hydrate stability zone (GHSZ), (2) identify and evaluate potential direct indications of hydrate occurrence through evaluation of interval of elevated acoustic velocity and/or seismic events of prospective amplitude and polarity, (3) mitigate geologic risk via regional seismic and stratigraphic facies analysis as well as seismic mapping of amplitude distribution along prospective horizons, and (4) mitigate further prospect risk through assessment of the evidence of gas presence and migration into the GHSZ. Although a wide range of occurrence types might ultimately become viable energy supply options, this approach, which has been tested in only a small number of locations worldwide, has directed prospect evaluation toward those sand-hosted, high-saturation occurrences that were presently considered to have the greatest future commercial potential.

  18. Geophysical survey at Tell Barri (Syria)

    Science.gov (United States)

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

    2010-05-01

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

  19. Redesigning Curricula in Geology and Geophysics

    Science.gov (United States)

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

    2015-12-01

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

  20. TEMPORAL VARIATIONS IN GEOPHYSICAL FIELDS AND EARTHQUAKE FORECASTING ISSUES

    Directory of Open Access Journals (Sweden)

    V. A. Parovyshny

    2015-09-01

    Full Text Available Results of the experimental long-term monitoring programme are presented. It is aimed at studying natural geophysical fields located above the gas deposit in the zone impacted by the active regional fault, and its objectives are to reveal how such fields are changing with time and to establish a relationship between the temporal changes and seismicity. According to the database it determines several typical indicators of variations in the geophysical fields, which take place only above the gas deposit. It is concluded that periods, when natural geophysical fields located above the gas deposit are unstable, are preceding the final phase of preparation of seismic events.

  1. PROSPECTING EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102820 Chen Zhongyun(CNOOC Ltd.Shanghai,Shanghai 200030,China);Chen Hua Using Surfer Automation to Plot Contour Maps(Computing Techniques for Geophysical and Geochemical Exploration,ISSN1001-1749,CN51-1242/P,31(4),2009,p.409-412,2 illus.,10 refs.,with English abstract)Key words:digital cartography,isopleth maps20102821 Hu Daogong(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China);Patrick J.Barosh Inspirations from the Sino-U.S.Cooperative Geological Mapping in the East Kunlun Orogenic Belt:Ideas and Methods(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,28(10),2009,p.1411-1418,5 illus.,14 refs.)Key words:geologic mapping,China,United StatesOn the basis of the practice of the Sino-U.S.cooperative geological mapping in the East Kunlun Orogenic Belt and through the comparative analysis of several geological mapping examples completed recently by USGS,the authors have a further knowledge of the method and idea of America geological mapping.The concept of "mapping all lithological unites" hasn’t changed within a difficult course of 130 years along with USGS’s evolution.The mapping method of "geological features guid

  2. Geophysical phenomena classification by artificial neural networks

    Science.gov (United States)

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

    1995-01-01

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

  3. GEOPHYSICAL TECHNIQUES IN DETECTION TO RIVER EMBANKMENTS

    Institute of Scientific and Technical Information of China (English)

    CHEN Chao; LIU Jian-ping; XU Shun-fang; XIA Jiang-hai

    2004-01-01

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

  4. Understanding biogeobatteries: Where geophysics meets microbiology

    Science.gov (United States)

    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.

  5. Advanced geophysical underground coal gasification monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, Robert; Yang, X.; White, J. A.; Ramirez, A.; Wagoner, J.; Camp, D. W.

    2014-07-01

    Underground Coal Gasification (UCG) produces less surface impact, atmospheric pollutants and greenhouse gas than traditional surface mining and combustion. Therefore, it may be useful in mitigating global change caused by anthropogenic activities. Careful monitoring of the UCG process is essential in minimizing environmental impact. Here we first summarize monitoring methods that have been used in previous UCG field trials. We then discuss in more detail a number of promising advanced geophysical techniques. These methods – seismic, electromagnetic, and remote sensing techniques – may provide improved and cost-effective ways to image both the subsurface cavity growth and surface subsidence effects. Active and passive seismic data have the promise to monitor the burn front, cavity growth, and observe cavity collapse events. Electrical resistance tomography (ERT) produces near real time tomographic images autonomously, monitors the burn front and images the cavity using low-cost sensors, typically running within boreholes. Interferometric synthetic aperture radar (InSAR) is a remote sensing technique that has the capability to monitor surface subsidence over the wide area of a commercial-scale UCG operation at a low cost. It may be possible to infer cavity geometry from InSAR (or other surface topography) data using geomechanical modeling. The expected signals from these monitoring methods are described along with interpretive modeling for typical UCG cavities. They are illustrated using field results from UCG trials and other relevant subsurface operations.

  6. Understanding biogeobatteries: Where geophysics meets microbiology

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

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

  7. Satellite gravity gradient grids for geophysics.

    Science.gov (United States)

    Bouman, Johannes; Ebbing, Jörg; Fuchs, Martin; Sebera, Josef; Lieb, Verena; Szwillus, Wolfgang; Haagmans, Roger; Novak, Pavel

    2016-02-11

    The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite aimed at determining the Earth's mean gravity field. GOCE delivered gravity gradients containing directional information, which are complicated to use because of their error characteristics and because they are given in a rotating instrument frame indirectly related to the Earth. We compute gravity gradients in grids at 225 km and 255 km altitude above the reference ellipsoid corresponding to the GOCE nominal and lower orbit phases respectively, and find that the grids may contain additional high-frequency content compared with GOCE-based global models. We discuss the gradient sensitivity for crustal depth slices using a 3D lithospheric model of the North-East Atlantic region, which shows that the depth sensitivity differs from gradient to gradient. In addition, the relative signal power for the individual gradient component changes comparing the 225 km and 255 km grids, implying that using all components at different heights reduces parameter uncertainties in geophysical modelling. Furthermore, since gravity gradients contain complementary information to gravity, we foresee the use of the grids in a wide range of applications from lithospheric modelling to studies on dynamic topography, and glacial isostatic adjustment, to bedrock geometry determination under ice sheets.

  8. Geophysical Surveys Over a Terminal Moraine

    Science.gov (United States)

    Bentley, L. R.; Langston, G.; Hayashi, M.

    2007-12-01

    Alpine watersheds represent the headwaters of many major rivers in western Canada. Consequently, understanding the hydrological cycle within these watersheds is critical for modeling the effects of climate change on water resources in western Canada and for developing informed water management strategies. Terminal moraines represent a significant hydrological response unit within many alpine watersheds in western Canada. Recent studies suggest that these features may provide sites for water storage. The preliminary results of a geophysical survey of a terminal moraine exhibiting geomorphological characteristics suggesting an ice-core will be presented. It is hypothesized that bedrock topography and the presence of ice creates barriers and channels groudwater flow. The focus of the survey was to delineate the hydrologically significant features within the moraine using electrical resistivity imaging (ERI), seismic refraction, and ground penetrating radar (GPR). Buried ice was easily detected using ERI due to high resistivity of over 1 MOhm-m. However, it was not as extensive as expected. Seismic refraction proved to be most useful in detecting the underlying bedrock. GPR images showed many reflection fragments but were noisy and difficult to interpret. Regions of relatively high electrical conductivity suggest some degree of channelization of groundwater in the vicinity of a tarn.

  9. Unified Geophysical Cloud Platform (UGCP) for Seismic Monitoring and other Geophysical Applications.

    Science.gov (United States)

    Synytsky, R.; Starovoit, Y. O.; Henadiy, S.; Lobzakov, V.; Kolesnikov, L.

    2016-12-01

    We present Unified Geophysical Cloud Platform (UGCP) or UniGeoCloud as an innovative approach for geophysical data processing in the Cloud environment with the ability to run any type of data processing software in isolated environment within the single Cloud platform. We've developed a simple and quick method of several open-source widely known software seismic packages (SeisComp3, Earthworm, Geotool, MSNoise) installation which does not require knowledge of system administration, configuration, OS compatibility issues etc. and other often annoying details preventing time wasting for system configuration work. Installation process is simplified as "mouse click" on selected software package from the Cloud market place. The main objective of the developed capability was the software tools conception with which users are able to design and install quickly their own highly reliable and highly available virtual IT-infrastructure for the organization of seismic (and in future other geophysical) data processing for either research or monitoring purposes. These tools provide access to any seismic station data available in open IP configuration from the different networks affiliated with different Institutions and Organizations. It allows also setting up your own network as you desire by selecting either regionally deployed stations or the worldwide global network based on stations selection form the global map. The processing software and products and research results could be easily monitored from everywhere using variety of user's devices form desk top computers to IT gadgets. Currents efforts of the development team are directed to achieve Scalability, Reliability and Sustainability (SRS) of proposed solutions allowing any user to run their applications with the confidence of no data loss and no failure of the monitoring or research software components. The system is suitable for quick rollout of NDC-in-Box software package developed for State Signatories and aimed for

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

    Science.gov (United States)

    Eppelbaum, Lev

    2015-04-01

    observe that as a result of the above operations we embedded the original data into 3-dimensional space where data related to the AT subsurface are well separated from the N data. This 3D set of the data representatives can be used as a reference set for the classification of newly arriving data. Geophysically it means a reliable division of the studied areas for the AT-containing and not containing (N) these objects. Testing this methodology for delineation of archaeological cavities by magnetic and gravity data analysis displayed an effectiveness of this approach. References Alperovich, L., Eppelbaum, L., Zheludev, V., Dumoulin, J., Soldovieri, F., Proto, M., Bavusi, M. and Loperte, A., 2013. A new combined wavelet methodology applied to GPR and ERT data in the Montagnole experiment (French Alps). Journal of Geophysics and Engineering, 10, No. 2, 025017, 1-17. Averbuch, A., Hochman, K., Rabin, N., Schclar, A. and Zheludev, V., 2010. A diffusion frame-work for detection of moving vehicles. Digital Signal Processing, 20, No.1, 111-122. Averbuch A.Z., Neittaanmäki, P., and Zheludev, V.A., 2014. Spline and Spline Wavelet Methods with Applications to Signal and Image Processing. Volume I: Periodic Splines. Springer. Coifman, R.R. and Lafon, S., 2006. Diffusion maps, Applied and Computational Harmonic Analysis. Special issue on Diffusion Maps and Wavelets, 21, No. 7, 5-30. Eppelbaum, L.V., 2011. Study of magnetic anomalies over archaeological targets in urban conditions. Physics and Chemistry of the Earth, 36, No. 16, 1318-1330. Eppelbaum, L.V., 2014a. Geophysical observations at archaeological sites: Estimating informational content. Archaeological Prospection, 21, No. 2, 25-38. Eppelbaum, L.V. 2014b. Four Color Theorem and Applied Geophysics. Applied Mathematics, 5, 358-366. Eppelbaum, L.V., Alperovich, L., Zheludev, V. and Pechersky, A., 2011. Application of informational and wavelet approaches for integrated processing of geophysical data in complex environments. Proceed

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

    Science.gov (United States)

    Duncan, D.; Davis, M. B.; Goff, J. A.; Gulick, S. P. S.; McIntosh, K. D.; Saustrup, S., Sr.

    2014-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers a three-week marine geology and geophysics field course during the spring-summer intersession. The course provides hands-on instruction and training for graduate and upper-level undergraduate students in high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples. Students participate in an initial three days of classroom instruction designed to communicate geological context of the field area along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. Our field sites at Port Aransas, and Galveston, TX, and Grand Isle, LA, provide ideal locations for students to investigate coastal processes of the Gulf Coast and continental shelf through application of geophysical techniques in an exploratory mode. At sea, students assist with survey design and instrumentation set up while learning about acquisition parameters, data quality control, trouble-shooting, and safe instrument deployment and retrieval. In teams of four, students work in onshore field labs preparing sediment samples for particle size analysis and data processing. During the course's final week, teams return to the classroom where they integrate, interpret, and visualize data in a final project using industry-standard software such as Echos, Landmark, Caris, and Fledermaus. The course concludes with a series of final presentations and discussions in which students examine geologic history and/or sedimentary processes represented by the Gulf Coast continental shelf with academic and industry supporters. Students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and low instructor to student ratio (sixteen

  12. A portable marine geophysical data access and management system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Narvekar, P.

    data and includes different marine geophysical parameters like bathymetry (corrected depths), magnetic (total magnetic field and magnetic anomaly) and gravity (observed gravity, Eotvos correction, free-air, Bouger anomalies, etc.). For the purpose...

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

    Science.gov (United States)

    McEntee, Christine

    2012-02-01

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

  14. Solar Geophysical Data (SGD) Reports (1955-2009)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Solar-Geophysical Data (SGD) reports were a comprehensive compilation of many different kinds of observational data of the sun's activity and its effects on the...

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

    Science.gov (United States)

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

    2012-12-01

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

  16. Development of Geophysical Ideas and Institutions in Ottoman Empire

    Science.gov (United States)

    Ozcep, Ferhat; Ozcep, Tazegul

    2015-04-01

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

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

    Science.gov (United States)

    Ozcep, F.; Ozcep, T.

    2014-09-01

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

  18. Quantitative geophysical log interpretation for rock mass characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Peter Hatherly; Renate Sliwa; Roland Turner; Terry Medhurst

    2004-04-01

    Geophysical borehole logging is routinely employed as part of exploration drilling in open pit and underground mining operations. Analysis of results is often empirical or based on theoretical considerations that need not relate to the actual properties of the rocks under consideration. The objectives of this project are to develop techniques for quantitative geophysical log interpretation techniques to enable: better estimation of coal and rock properties such as strength and permeability; better lithological interpretation and strata correlation between boreholes; a rock mass rating scheme for mine design purposes which is based on geophysical logging. This study has placed the techniques for quantitative geophysical log assessment on a firm footing. The authors have demonstrated an approach for log assessment that can be routinely applied. Many of the mineralogical and physical rock properties that impact on the assessments have been investigated and discussed. They have also demonstrated the benefits of quantitative geophysical log assessment. The major recommendation made is that geologists and engineers in the coal mining industry take the time to study this report and begin to put the approach described into practice. The collective understanding that this experience will provide can only help fuel the drive to take the benefits of geophysical logging to greater levels.

  19. HydroImage: A New Software for HydroGeophysical and BioGeophysical Data Integration

    Science.gov (United States)

    Suribhatla, R. M.; Mok, C. M.; Kaback, D.; Chen, J.; Hubbard, S. S.

    2011-12-01

    Hydrogeophysical and biogeophysical data integration have recently emerged as cost-effective and rapid techniques for improving subsurface characterization and monitoring. In a Bayesian framework for integration, borehole based data provide prior distribution and geophysical information serve as data to update the prior through likelihood functions obtained from petrophysical models between borehole and cross-well data. We present the application of a Windows-based software called HydroImage that uses this Bayesian framework for data integration and visualization. HydroImage can be used for geostatistical estimation, geophysical tomographic inversion, petrophysical model development, and Bayesian integration. We demonstrate HydroImage using three different field datasets to estimate different subsurface states or parameters. The first example combines wellbore flowmeter test data and crosshole seismic and ground penetrating radar (GPR) data to estimate hydraulic conductivity at the DOE Bacterial Transport Site in Oyster, Virginia. The second example focuses on using time-lapse radar data to estimate moisture content dynamics associated with a desiccation test performed to remediate the deep vadose zone in Hanford, Washington. The third example demonstrates the use of spectral induced polarization data to estimate the spatial and temporal distribution of geochemical parameters that are indicative of the redox state of a contaminated aquifer.

  20. Quality control for quantitative geophysical logging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Kyu; Hwang, Se Ho; Hwang, Hak Soo; Park, In Hwa [Korea Institute of Geology Mining and Materials, Taejon (Korea)

    1998-12-01

    Despite the great availability of geophysical data obtained from boreholes, the interpretation is subject to significant uncertainties. More accurate data with less statistical uncertainties should require an employment of more quantitative techniques in log acquisition and interpretation technique. The long-term objective of this project is the development of techniques in both quality control of log measurement and the quantitative interpretation. In the first year, the goals of the project will include establishing the procedure of log acquisition using various tests, analysing the effect of logging velocity change on the logging data, examining the repeatability and reproducibility, analyzing of filtering effect on the log measurements, and finally the zonation and the correlation of single-and inter-well log data. For the establishment of logging procedure, we have tested the multiple factors affecting the accuracy in depth. The factors are divided into two parts: human and mechanical. These factors include the zero setting of depth, the calculation of offset for the sonde, the stretching effect of cable, and measuring wheel accuracy. We conclude that the error in depth setting results primarily from human factor, and also in part from the stretching of cable. The statistical fluctuation of log measurements increases according to increasing the logging speed for the zone of lower natural gamma. Thus, the problem related with logging speed is a trifling matter in case of the application of resources exploration, the logging speed should run more slowly to reduce the statistical fluctuation of natural gamma with lithologic correlation in mind. The repeatability and reproducibility of logging measurements are tested. The results of repeatability test for the natural gamma sonde are qualitatively acceptable in the reproducibility test, the errors occurs in logging data between two operators and successive trials. We conclude that the errors result from the

  1. Unleashing Geophysics Data with Modern Formats and Services

    Science.gov (United States)

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

    2016-04-01

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

  2. Geoelectrical prospecting of glauberite deposits in the Ebro basin (Spain)

    OpenAIRE

    Guinea, Ander; Playà, Elisabet; Rivero, Lluís; Salvany Duran, Josep Maria

    2014-01-01

    Glauberite (Na2Ca[SO4]2) is an evaporitic mineral which is used in the industries of detergents, paper, glass, pharmacy, etc. Glauberite rocks are seldom found cropping out because they are very sensitive to weathering processes; for this reason their prospection is conducted by means of boreholes. Nowadays, geophysical techniques are not used to support the characterization of glauberite deposits due to the lack of knowledge of their physical properties. In this study geoelectrical method...

  3. Geophysical Contribution in the Characterization of Deep Water Tables Geometry (Sidi Bouzid, Central Tunisia

    Directory of Open Access Journals (Sweden)

    D. Khazri

    2015-01-01

    Full Text Available Geophysical data combined with geological and hydrogeological data were analyzed to characterize the geometry of Oued El Hajel and Ouled Asker deep water tables (Sidi Bouzid. The obtained results allowed refining the geostructural schema by highlighting the individualization of the NE-SW underground convexity of Ouled Asker and the anticline of axis Es Souda-Hmaeima and Ezaouia on either sides of two hydrogeological thresholds. The geometrical analysis determined the spatial extension of Ouled Asker and Oued El Hajel subbasins. The seismic cartography of semideep and deep reservoirs (Oligo-Miocene; Eocene and upper Cretaceous associated with the main subbasins contributed to proposing hydrogeological prospect zones for a rationalized groundwater exploitation.

  4. Geophysical Investigation for Groundwater Development at Oyo State Housing Estate Ogbomosho, Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Olagoke Peter Oladejo

    Full Text Available Water is life because it is one of the inevitable ingredients for life survival. The urge for ground water development is very high in Oyo state Housing Estate, Ogbomosho, Southwestern Nigeria. Because the site is experiencing structural developments and there is no other source of water nearby. Surface water is becoming inadequate, thus this study aimed at investigating the hydro geological prospects of the area with a view to delineating for groundwater and its development. Geophysical investigation was carried out in the study area using Very Low Frequency (VLF method. VLF profiling of 20 m inter stations and 50 m of inter profiling distances were established. This study revealed a number of conductive zones for ground water development for both domestic and commercial purposes.

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

    Science.gov (United States)

    Auken, E.

    2012-12-01

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

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

    Science.gov (United States)

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

    2011-12-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Erosion of a model geophysical fluid

    Science.gov (United States)

    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

  9. The Unconventional Revolution in Exploration Geophysics

    Science.gov (United States)

    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

    Science.gov (United States)

    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. Ceres' Geophysical Evolution Inferred from Dawn Data

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2009-04-01

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

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

    Science.gov (United States)

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

    2016-11-01

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

  14. Geophysical Exploration of Tyuonyi Ruins in Bandelier National Monument, New Mexico, USA

    Science.gov (United States)

    Wilson, A. L.; Taylor-Offord, S.; Rosado, A.; Ly, P.; Gonzales, J.; Civitello, J. A.; Johnston, G.; Ferguson, J. F.; McPhee, D.; Pellerin, L.

    2016-12-01

    Students and faculty from the Summer of Applied Geophysical Experience (SAGE) used several near-surface, non-invasive geophysical techniques to survey a site on the Tyuonyi Pueblo in northern New Mexico. The methods applied include ground penetrating radar (GPR), magnetics, electromagnetic induction, and seismic refraction. These efforts represent the first ever geophysical investigation of the Tyuonyi Pueblo, which lies in Frijoles Canyon, within the Bandelier National Monument. Tyuonyi was first excavated from 1908-1912 by archeologist Edgar L. Hewett, exposing 250 ground floor room blocks. A small northwest segment of the pueblo was left unexcavated, leaving a dirt mound above which the modern trail crosses. Much of the displaced sediments from Hewett's excavation were piled a few meters north of the room blocks. Both areas are of interest due to plans by Bandelier National Monument to redirect the trail to a new position north of the room blocks on top of the spoil pile. The primary goal of the geophysical survey was to investigate the subsurface in and around the spoil pile, particularly in the vicinity of the proposed new path location in order to identify the locations of any potentially archeologically important artifacts which could interfere with construction of the new path. A secondary objective of the survey was to investigate the dirt mound to attempt to determine if the room blocks extend underneath the mound and possibly connect in the subsurface. The seismic refraction survey reveals a kiva-like feature inside the plaza close to the NW room blocks; wall room features are also observed under the mound. The GPR grid survey, which covered the unexcavated portion of the pueblo, reveals several point reflections that produce an arc formation that lines up with the existing room blocks southwest of the survey grid. Magnetics data show a number of shallow and moderate-depth anomalies. Broad scale trends indicate reworking of near-surface soil and rock

  15. Uranium ore prospecting and exploration with a special view to sedimentary deposits, illustrated by the example of the Muellenbach deposit. [Federal Republic of Germany

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H.

    1981-08-01

    The Muellenbach deposit near Baden-Baden (northern Black Forest) is used as an example to illustrate the prospecting and exploration methods of Messrs. Saarberg-Interplan which includes: airborne measurements, carborne measurements, Ru measurements near the ground, drills to detect ground anomalies, borehole logging, photosurveys, geochemistry, geophysical surface prospecting, mining exploration, radiation protection.

  16. Baksan Neutrino Observatory of the INR RAS: current state and prospects

    Science.gov (United States)

    Kuzminov, V. V.

    2016-06-01

    An overall view of the Baksan Neutrino Observatory of the INR RAS infrastructure is presented. Ground-based and underground facilities used to study cosmic rays, rare nuclear reactions and decays, to register solar neutrino, to observe various geophysical phenomena are described. Some main results obtained with these facilities and prospects are given.

  17. Field Geophysics at SAGE: Strategies for Effective Education

    Science.gov (United States)

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

    2011-12-01

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

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

    Science.gov (United States)

    Valencio, Daniel A.; Schneider, Otto

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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/.

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

    Energy Technology Data Exchange (ETDEWEB)

    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/.

  1. Time-lapse Joint Inversion of Geophysical Data and its Applications to Geothermal Prospecting - GEODE

    Energy Technology Data Exchange (ETDEWEB)

    Revil, Andre [Univ. of Savoy, Chambery (France)

    2015-12-31

    The objectives of this project were to develop new algorithms to decrease the cost of drilling for geothermal targets during the exploration phase of a hydrothermal field and to improve the monitoring of a geothermal field to better understand its plumbing system and keep the resource renewable. We developed both new software and algorithms for geothermal explorations (that can also be used in other areas of interest to the DOE) and we applied the methods to a geothermal field of interest to ORMAT in Nevada.

  2. Geophysical prospecting for iron ore deposit around Tajimi village, Lokoja, North-Central Nigeria

    Science.gov (United States)

    Bayowa, Oyelowo; Ogungbesan, Gbenga; Majolagbe, Razak; Oyeleke, Simeon

    2016-09-01

    Ground magnetic and electrical resistivity survey were undertaken to investigate the occurrence and geometry of iron ore deposit around Tajimi village, Lokoja, North-Central Nigeria. The generated residual map of the ground-magnetic data acquired at 250 stations along 15 traverses revealed numerous prominent anomalies, mostly trending in the N-S direction. The radial power spectrum revealed the depth to magnetic sources between 6 m to 20 m. The interpreted VES data characterized the area into three subsurface layers: top soil, presumably iron ore layer and weathered/fresh basement. The result of vertical electrical sounding curves showed a sudden drop in resistivity (42-241 Ωm) over high magnetic response. The geo-electric section revealed that the study area is generally characterized with thin overburden (0.5-1.7 m) and the thickness of the second layer (presumed to be the iron ore layer) ranged between 6.2-25.1 m. The study concluded that areas of high magnetic intensity showed a sudden drop in resistivity value for the VES points, which give an indication of the presence of an electrically conductive structure presumed to be iron ore deposits.

  3. Geophysical methods for locating abandoned wells

    Science.gov (United States)

    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

  4. Geophysical Constraints on Sediment Dispersal Systems

    Science.gov (United States)

    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

  5. Towards an Operational Use of Geophysics for Archaeology in Henan (China: Methodological Approach and Results in Kaifeng

    Directory of Open Access Journals (Sweden)

    Nicola Masini

    2017-08-01

    Full Text Available One of the major issues in buried archeological sites especially if characterized by intense human activity, complex structures, and several constructive phases, is: to what depth conduct the excavation? The answer depends on a number of factors, among these one of the most important is the a priori and reliable knowledge of what the subsoil can preserve. To this end, geophysics (if used in strong synergy with archaeological research can help in the planning of time, depth, and modes of excavation also when the physical characteristics of the remains and their matrix are not ideal for archaeo-geophysical applications. This is the case of a great part of the archaeological sites in Henan, the cradle of the most important cultures in China and the seat of several capitals for more than two millennia. There, the high depth of buried remains covered by alluvial deposits and the building materials, mainly made by rammed earth, did not favor the use of geophysics. In this paper, we present and discuss the GPR and ERT prospection we conducted in Kaifeng (Henan, China, nearby a gate of the city walls dated to the Northern Song Dynasty. The integration of GPR and ERT provided useful information for the identification and characterization of archaeological remains buried at different depths. Actually, each geophysical technique, GPR frequency (used for the data acquisition as well as each way to analyze and visualize the results (from radargrams to time slice only provided partial information of little use if alone. The integration of the diverse techniques, data processing and visualization enabled us to optimize the penetration capability, the resolution for the detection of archaeological features and their interpretation. Finally, the results obtained from the GPR and ERT surveys were correlated with archaeological stratigraphy, available nearby the investigated area. This enabled us to further improve the interpretation of results from GPR and ERT

  6. Geophysical logging for groundwater investigations in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Phongpiyah Klinmanee

    2012-09-01

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

  7. Joint geophysical data analysis for geothermal energy exploration

    Science.gov (United States)

    Wamalwa, Antony Munika

    Geophysical data modelling often yields non-unique results and hence the interpretation of the resulting models in terms of underlying geological units and structures is not a straightforward problem. However, if multiple datasets are available for a region of study, an integrated interpretation of models for each of the geophysical data may results to a more realistic geological description. This study not only demonstrates the strength of resistivity analysis for geothermal fields but also the gains from interpreting resistivity data together with other geophysical data such as gravity and seismic data. Various geothermal fields have been examined in this study which includes Silali and Menengai geothermal fields in Kenya and Coso geothermal field in California, USA.

  8. Spatial analysis of oil reservoirs using DFA of geophysical data

    Directory of Open Access Journals (Sweden)

    R. A. Ribeiro

    2014-04-01

    Full Text Available We employ Detrended Fluctuation Analysis (DFA technique to investigate spatial properties of an oil reservoir. This reservoir is situated at Bacia de Namorados, RJ, Brazil. The data corresponds to well logs of the following geophysical quantities: sonic, gamma ray, density, porosity and electrical resistivity, measured in 56 wells. We tested the hypothesis of constructing spatial models using data from fluctuation analysis over well logs. To verify this hypothesis we compare the matrix of distances among well logs with the differences among DFA-exponents of geophysical quantities using spatial correlation function and Mantel test. Our data analysis suggests that sonic profile is a good candidate to represent spatial structures. Then, we apply the clustering analysis technique to the sonic profile to identify these spatial patterns. In addition we use the Mantel test to search for correlation among DFA-exponents of geophysical quantities.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    Three cross-borehole geophysical methods are used to image water migration in the unsaturated zone after a point injection of water. Mass balance calculations and moment analysis highlight the differences in resolution between the methods. The choice of moisture content threshold value significan......Three cross-borehole geophysical methods are used to image water migration in the unsaturated zone after a point injection of water. Mass balance calculations and moment analysis highlight the differences in resolution between the methods. The choice of moisture content threshold value...... significantly influences results of the moment analysis. We compare results of three cross-borehole geophysical approaches for imaging tracer migration arising from a point injection of water in the unsaturated zone: three-dimensional electrical resistivity tomography (ERT), two-dimensional ground...

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

    Science.gov (United States)

    Currenti, Gilda M.; Napoli, Rosalba

    2017-05-01

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

  11. Teaching Computational Geophysics Classes using Active Learning Techniques

    Science.gov (United States)

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

    2016-12-01

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

  12. Compatible finite element spaces for geophysical fluid dynamics

    CERN Document Server

    Natale, Andrea

    2016-01-01

    Compatible finite elements provide a framework for preserving important structures in equations of geophysical fluid dynamics, and are becoming important in their use for building atmosphere and ocean models. We survey the application of compatible finite element spaces to geophysical fluid dynamics, including the application to the nonlinear rotating shallow water equations, and the three-dimensional compressible Euler equations. We summarise analytic results about dispersion relations and conservation properties, and present new results on approximation properties in three dimensions on the sphere, and on hydrostatic balance properties.

  13. Annals of the international geophysical year ionospheric drift observations

    CERN Document Server

    Rawer, K; Beloussov, V V; Beynon, W J G

    2013-01-01

    Annals of the International Geophysical Year, Volume 33: Results of Ionospheric Drift Observations describes the systematic changes in individual ionospheric observations during the International Geophysical Year (IGY). This book is composed of four chapters, and begins with a presentation of the general data on stations and the lists of publications concerning drift work during IGY/IGC. The next chapter contains the results obtained mainly by intercomparison of the time shift between fadings observed on three antenna separated by a distance of roughly a wavelength. These data are followed by

  14. 3D stochastic geophysical inversion for contact surface geometry

    Science.gov (United States)

    Lelièvre, Peter; Farquharson, Colin; Bijani, Rodrigo

    2015-04-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. As such, 3D geological Earth models typically comprise wireframe contact surfaces of tessellated triangles or other polygonal planar facets. In contrast, standard minimum-structure geophysical inversions are performed on meshes of space-filling cells (typically prisms or tetrahedra) and recover smoothly varying physical property distributions that are inconsistent with typical geological interpretations. There are several approaches through which mesh-based geophysical inversion can help recover models with some of the desired characteristics. However, a more effective strategy is to consider a fundamentally different type of inversion that works directly with models that comprise surfaces representing contacts between rock units. We are researching such an approach, our goal being to perform geophysical forward and inverse modelling directly with 3D geological models of any complexity. Geological and geophysical models should be specified using the same parameterization such that they are, in essence, the same Earth model. We parameterize the wireframe contact surfaces in a 3D model as the coordinates of the nodes (facet vertices). The physical properties of each rock unit in a model remain fixed while the geophysical inversion controls the position of the contact surfaces via the control nodes, perturbing the surfaces as required to fit the geophysical data responses. This is essentially a "geometry inversion", which can be used to recover the unknown geometry of a target body or to investigate the viability of a proposed Earth model. We apply global optimization strategies to solve the inverse problem, including stochastic sampling to obtain statistical information regarding the likelihood of particular features in the model, helping to assess the viability of a proposed model. Jointly inverting multiple types of geophysical data is simple

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

    DEFF Research Database (Denmark)

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

    both ground-based and airborne geophysical methods as well as extensive water quality sampling. The occurrence of saline groundwater follows a clear spatial pattern and appears to be related to the palaeo Lake Makgadikgadi, whose northernmost extension reached into the Machile area. Because the lake...... precipitation has formed limited freshwater reservoirs in a generally saline area, which need to be sustainably managed. We will present initial results from the geophysical and geochemical surveys conducted over the past few years. We will interpret these findings in terms of the geologic history of Southern...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, Yoram

    2001-01-01

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

  19. Geophysical investigations with TOPEX/Poseidon altimetry data

    Science.gov (United States)

    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.

  20. Imaging of Ground Ice with Surface-Based Geophysics

    Science.gov (United States)

    2015-10-01

    transects; therefore, lengths were not the same for all transects. We flagged each transect every 10 m for fiducial markings to be used by the geophysics...July, Zurich, Switzerland , ed. M. Phillips, S. M. Springman, and L. U. Arenson, 2:1289–1294. Rotterdam, Netherlands: A.A. Balkema Publishers

  1. Geophysical Evaluation for Wadi Rayan Field, Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    Adel Othman

    2016-03-01

    There are two intervals of producing sandstone which not only vary from one well to another but also not deposited in some wells. For these reasons, it is important to integrate all available geological and geophysical data to come up with a model for ARG reservoir.

  2. Synchronization of Stochastic Two-Layer Geophysical Flows

    Institute of Scientific and Technical Information of China (English)

    HAN Yongqian

    2011-01-01

    In this paper, the two-layer quasigeostrophic flow model under stochastic wind forcing is considered. It is shown that when the layer depth or density difference across the layers tends to zero, the dynamics on both layers synchronizes to an averaged geophysical flow model.

  3. Addressing the difficulty of changing fields in geophysics

    Science.gov (United States)

    Civilini, F.; Savage, M. K.

    2014-12-01

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

  4. The Role of Geophysics in the New Global Tectonics

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  7. Geophysical Monitoring of Two types of Subsurface Injection

    Science.gov (United States)

    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...

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

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    -small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  9. Geophysics of an Oceanic Ice Shell on Snowball Earth

    Science.gov (United States)

    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.

  10. Helheim 2006: Integrated Geophysical Observations of Glacier Flow

    DEFF Research Database (Denmark)

    Nettles, M.; Ahlstrøm, A.; Elosegui, P.

    During the summer field season, 2006, we undertook a pilot geophysical experiment at Helheim Glacier, East Greenland, in which we deployed a network of GPS instruments on and around the glacier to measure the ice deformation field as a function of time. The experiment was motivated by the discovery...

  11. A physicist in the world of geophysics and space

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.A. [Univ. of Chicago, IL (United States)

    1994-10-01

    The author discusses his early work after WW II in the study of cosmic rays, and geophysical issues and space physics. His early work was on the proton primary cosmic ray spectrum, looking at neutron spectra. These studies were incorporated into the IGY work, and hence expanded. Experimental investigation of the Forbush effect is discussed.

  12. Geophysical data fusion for subsurface imaging. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Geophysical monitoring at the Cerro Prieto geothermal field

    Science.gov (United States)

    Wilt, M.; Zelwer, R.; Majer, E. L.

    1982-09-01

    A program of reservoir monitoring at the Cerro Prieto geothermal field using surface geophysical methods with the objective of observing changes resulting from production is described. The three methods used, dipole-dipole resistivity, precision gravity, and passive seismic monitoring, are discussed.

  14. The impact of approximations and arbitrary choices on geophysical images

    NARCIS (Netherlands)

    Valentine, A.P.; Trampert, J.A.

    2016-01-01

    Whenever a geophysical image is to be constructed, a variety of choices must be made. Some, such as those governing data selection and processing, or model parametrization, are somewhat arbitrary: there may be little reason to prefer one choice over another. Others, such as defining the theoretical

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

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    -small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  16. About well-posed definition of geophysical fields'

    Science.gov (United States)

    Ermokhine, Konstantin; Zhdanova, Ludmila; Litvinova, Tamara

    2013-04-01

    We introduce a new approach to the downward continuation of geophysical fields based on approximation of observed data by continued fractions. Key Words: downward continuation, continued fraction, Viskovatov's algorithm. Many papers in geophysics are devoted to the downward continuation of geophysical fields from the earth surface to the lower halfspace. Known obstacle for the method practical use is a field's breaking-down phenomenon near the pole closest to the earth surface. It is explained by the discrepancy of the studied fields' mathematical description: linear presentation of the field in the polynomial form, Taylor or Fourier series, leads to essential and unremovable instability of the inverse problem since the field with specific features in the form of poles in the lower halfspace principally can't be adequately described by the linear construction. Field description by the rational fractions is closer to reality. In this case the presence of function's poles in the lower halfspace corresponds adequately to the denominator zeros. Method proposed below is based on the continued fractions. Let's consider the function measured along the profile and represented it in the form of the Tchebishev series (preliminary reducing the argument to the interval [-1, 1]): There are many variants of power series' presentation by continued fractions. The areas of series and corresponding continued fraction's convergence may differ essentially. As investigations have shown, the most suitable mathematical construction for geophysical fields' continuation is so called general C-fraction: where ( , z designates the depth) For construction of C-fraction corresponding to power series exists a rather effective and stable Viskovatov's algorithm (Viskovatov B. "De la methode generale pour reduire toutes sortes des quantitees en fraction continues". Memoires de l' Academie Imperiale des Sciences de St. Petersburg, 1, 1805). A fundamentally new algorithm for Downward Continuation

  17. COTHERM: Geophysical Modeling of High Enthalpy Geothermal Systems

    Science.gov (United States)

    Grab, Melchior; Maurer, Hansruedi; Greenhalgh, Stewart

    2014-05-01

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

  18. Geophysical Methods for Investigating Ground-Water Recharge

    Science.gov (United States)

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

    2007-01-01

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

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

    OpenAIRE

    Peng, Fenglin; Ma, Maining; Peng, Le; Zhang, Jian; Chen, Gengxiong; Li, Yufang; Sun, Bo; Zhang, Yunfei

    2013-01-01

    In this report we introduce the development of the WDC for Geophysics, Beijing included our activities in the electronic Geophysical Year (eGY) and in the transition period from WDC to WDS. We also present our future plans. We have engaged in the development of geophysical informatics and related data science. We began the data visualization of geomagnetic fields in the GIS system. Our database has been expanded from geomagnetic data to the data of solid geophysics, including geothermal data,...

  20. Integrating geophysics and hydrology for reducing the uncertainty of groundwater model predictions and improved prediction performance

    DEFF Research Database (Denmark)

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

    constructed from geological and hydrological data. However, geophysical data are increasingly used to inform hydrogeologic models because they are collected at lower cost and much higher density than geological and hydrological data. Despite increased use of geophysics, it is still unclear whether......, ‘true’, hydrogeological and geophysical systems. The two types of ‘true’ systems can be used together with corresponding forward codes to generate hydrological and geophysical datasets, respectively. These synthetic datasets can be interpreted using any hydrogeophysical inversion scheme...

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

    Science.gov (United States)

    Piro, Salvatore; Papale, Enrico; Zamuner, Daniela

    2016-04-01

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

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

    Science.gov (United States)

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

    Science.gov (United States)

    2014-09-01

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

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

    Science.gov (United States)

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

    2016-12-01

    The University of Texas Institute for Geophysics, Jackson School of Geosciences, offers a 3-week marine geology and geophysics field course. The course provides hands-on instruction and training for graduate and upper-level undergraduate students in high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, and sediment sampling and analysis. Students first participate in 3 days of classroom instruction designed to communicate geological context of the field area along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work at locations that provide an opportunity to investigate coastal and continental shelf processes. Teams of students rotate between UTIG's 26' R/V Scott Petty and NOAA's 82' R/V Manta. They assist with survey design, instrumentation set up, and learn about acquisition, quality control, and safe instrument deployment. Teams also process data and analyze samples in onshore field labs. During the final week teams integrate, interpret, and visualize data in a final project using industry-standard software. The course concludes with team presentations on their interpretations with academic and industry supporters. Students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and high instructor/student ratio (sixteen students, three faculty, and three teaching assistants). Post-class, students may incorporate course data in senior honors or graduate thesis and are encouraged to publish and present results at national meetings. This course (to our knowledge) remains the only one of its kind, satisfies field experience requirements for some degree programs, and provides an alternative to land-based field courses. Alumni note the course's applicability to energy, environmental, and geotechnical industries as well as coastal restoration/management fields.

  5. Geoarchaeological prospection of a Medieval manor in the Dutch polders using an electromagnetic induction sensor in combination with soil augerings

    NARCIS (Netherlands)

    Simpson, D.; Lehouck, A.; Meirvenne, M.; Bourgeois, J.; Thoen, E.; Vervloet, J.

    2008-01-01

    In archaeological prospection, geophysical sensors are increasingly being used to locate buried remains within their natural context. To cover a large area in sufficient detail, an electromagnetic induction sensor can be very useful, measuring simultaneously the electrical conductivity and the magne

  6. Geophysical data fusion for subsurface imaging. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

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

  7. NATO Advanced Study Institute on Buoyant Convection in Geophysical Flows

    CERN Document Server

    Fedorovich, E; Viegas, D; Wyngaard, J

    1998-01-01

    Studies of convection in geophysical flows constitute an advanced and rapidly developing area of research that is relevant to problems of the natural environment. During the last decade, significant progress has been achieved in the field as a result of both experimental studies and numerical modelling. This led to the principal revision of the widely held view on buoyancy-driven turbulent flows comprising an organised mean component with superimposed chaotic turbulence. An intermediate type of motion, represented by coherent structures, has been found to play a key role in geophysical boundary layers and in larger scale atmospheric and hydrospheric circulations driven by buoyant forcing. New aspects of the interaction between convective motions and rotation have recently been discovered and investigated. Extensive experimental data have also been collected on the role of convection in cloud dynamics and microphysics. New theoretical concepts and approaches have been outlined regarding scaling and parameteriz...

  8. Relationship of Worldwide Rocket Launch Crashes with Geophysical Parameters

    Directory of Open Access Journals (Sweden)

    N. Romanova

    2013-01-01

    Full Text Available A statistical comparison of launch crashes at different worldwide space ports with geophysical factors has been performed. A comprehensive database has been compiled, which includes 50 years of information from the beginning of the space age in 1957 about launch crashes occurring world-wide. Special attention has been paid to statistics concerning launches at the largest space ports: Plesetsk, Baikonur, Cape Canaveral, and Vandenberg. In search of a possible influence of geophysical factors on launch failures, such parameters as the vehicle type, local time, season, sunspot number, high-energy electron fluxes, and solar proton events have been examined. Also, we have analyzed correlations with the geomagnetic indices as indirect indicators of the space weather condition. Regularities found in this study suggest that further detailed studies of space weather effects on launcher systems, especially in the high-latitude regions, should be performed.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

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

  10. Integrated software framework for processing of geophysical data

    Science.gov (United States)

    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.

  11. Simulated geophysical monitoring of radioactive waste repository barriers

    Science.gov (United States)

    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.

  12. Relations of PC indices to further geophysical activity parameters.

    Science.gov (United States)

    Stauning, P.

    2012-04-01

    The Polar Cap (PC) indices, PCN for the index values derived from Thule magnetic data and PCS derived from Vostok data, relate to the polar cap ionospheric plasma convection driven mainly by the interaction of the solar wind with the magnetosphere. Thus, the PC indices serve to monitor the input power from the solar wind which drives a range of geophysical disturbances such as magnetic storms and substorms, energization of the plasma trapped in the Earth's near space, auroral activity, and heating of the upper atmosphere. The presentation will demonstrate the relations between the PC indices and further parameters and indices used to describe geophysical activity such as polar cap potentials, auroral electrojet activity, Joule and particle heating of the upper atmosphere, mid-latitude magnetic variations, and ring current indices Dst, SYM-H and ASY-H.

  13. A spectral-geophysical approach for detecting pipeline leakage

    Science.gov (United States)

    van der Meijde, M.; van der Werff, H. M. A.; Jansma, P. F.; van der Meer, F. D.; Groothuis, G. J.

    2009-02-01

    Leakage of hydrocarbon has a large economic and environmental impact. Traditional methods for investigating leakage and resulting pollution, such as drilling, are destructive, time consuming and expensive. Remote sensing is an alternative that is non-destructive and has been been tested extensively for exploration of onshore hydrocarbon reservoirs and detection of hydrocarbons at the Earth's surface. In this research, a leaking pipeline is investigated through field reflectance spectrometry and the findings are validated with traditional drilling and geophysical measurements. The measurements show a significant increase of vegetation anomalies on the pipeline with respect to areas further away. The observed anomalies are positively related to hydrocarbon pollution through chemical analysis of drillings. Subsurface geophysical measurements show a large correlation with observed surface vegetation stress, enhancing the identification of hydrocarbon-related vegetation stress through spectroscopy.

  14. Dunlop receives European Geophysical Society's Néel Medal

    Science.gov (United States)

    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.”

  15. Geology and Geophysics of new boreholes at the FEBEX site

    Energy Technology Data Exchange (ETDEWEB)

    Carbonell, R.; Perez-Estaun, A. [Inst. Jaume Almera, CSIC (Spain); Missana, T.; Buil, B.; Garralon, A.; Gomez, J. [CIEMAT (Spain); Suso, J.; Carretero, G.; Bueno, J.; Martinez, L. [AITEMIN (Spain); Hernan, P. [ENRESA (Spain)

    2007-06-15

    Geophysical data has been acquired to characterized the fracture network of the surrounding volume within the FEBEX gallery. The geophysic data include new borehole logging such as Natural Gamma and Borehole Ground Penetrating radar and cross hole ultrasonic tomography. The preliminary processing and integration of these different data sets indicates that the GPR record can provide images of the fractures, specially if they are fluid filled. The GPR is specially sensitive to the water content as it directly affects the electrical conductivity and the dielectric permittivity Therefore it is adequate for mapping water conductive fractures of the crystalline rock. The correlation of the anomalies measured by the natural gamma can be correlated with the 'diffractions' in the GPR and the fractures imaged by the borehole televiewer. The cross hole ultrasonic tomography data is under processing and no interpretations have been attempted yet.

  16. Geophysical study in waste landfill localized above fractured rocks

    Directory of Open Access Journals (Sweden)

    Ariveltom Cosme da Silva

    2011-08-01

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

  17. Structure-coupled multiphysics imaging in geophysical sciences

    Science.gov (United States)

    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.

  18. Swarm intelligence optimization and its application in geophysical data inversion

    Institute of Scientific and Technical Information of China (English)

    Yuan Sanyi; Wang Shangxu; Tian Nan

    2009-01-01

    The inversions of complex geophysical data always solve multi-parameter, nonlinear, and multimodal optimization problems. Searching for the optimal inversion solutions is similar to the social behavior observed in swarms such as birds and ants when searching for food. In this article, first the particle swarm optimization algorithm was described in detail, and ant colony algorithm improved. Then the methods were applied to three different kinds of geophysical inversion problems: (1) a linear problem which is sensitive to noise, (2) a synchronous inversion of linear and nonlinear problems, and (3) a nonlinear problem. The results validate their feasibility and efficiency. Compared with the conventional genetic algorithm and simulated annealing, they have the advantages of higher convergence speed and accuracy. Compared with the quasi-Newton method and Levenberg-Marquardt method, they work better with the ability to overcome the locally optimal solutions.

  19. Mobile NMR for geophysical analysis and materials testing

    Institute of Scientific and Technical Information of China (English)

    BLUMICH Bernhard; MAULER Jǒrg; HABER Agnes; PERLO Juan; DANIELI Ernesto; CASANOVA Federico

    2009-01-01

    Initiated by well logging NMR, portable NMR instruments are being developed for a variety of novel applications in materials testing, process analysis and control, which provides new opportunities for geophysical investigations. Small-diameter cylindrical sensors can probe short distances into the walls of slim-line logging holes, and single-sided sensors enable non-destructive testing of large objects. Both sensors are characterized by small sensitive volumes. Barrel-shaped magnets that accommodate the sample in their center have higher sensitivity due to a larger sensitive volume but can accommodate only samples like drill cores, which fit in size to the diameter of the magnet bore. Both types of magnets can be scaled down to the size of a coffee mug to arrive at sub-compact NMR equipment. Portable NMR magnets are reviewed in the context of applications related to geophysics.

  20. MPDATA: A positive definite solver for geophysical flows

    Energy Technology Data Exchange (ETDEWEB)

    Smolarkiewicz, P.K.; Margolin, L.G. [Los Alamos National Lab., NM (United States)

    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.

  1. Spectral analysis and filter theory in applied geophysics

    CERN Document Server

    Buttkus, Burkhard

    2000-01-01

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

  2. Gas dynamics an introduction with examples from astrophysics and geophysics

    CERN Document Server

    Achterberg, Abraham

    2016-01-01

    This book lays the foundations of gas- and fluid dynamics. The basic equations are developed from first principles, building on the (assumed) knowledge of Classical Mechanics. This leads to the discussion of the mathematical properties of flows, conservation laws, perturbation analysis, waves and shocks. Most of the discussion centers on ideal (frictionless) fluids and gases. Viscous flows are discussed when considering flows around obstacles and shocks. Many of the examples used to illustrate various processes come from astrophysics and geophysical phenomena.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-03-01

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

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

    Science.gov (United States)

    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

  5. Application of Huang-Hilbert Transforms to Geophysical Datasets

    Science.gov (United States)

    Duffy, Dean G.

    2003-01-01

    The Huang-Hilbert transform is a promising new method for analyzing nonstationary and nonlinear datasets. In this talk I will apply this technique to several important geophysical datasets. To understand the strengths and weaknesses of this method, multi- year, hourly datasets of the sea level heights and solar radiation will be analyzed. Then we will apply this transform to the analysis of gravity waves observed in a mesoscale observational net.

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

    Science.gov (United States)

    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.

  7. Space Geodesy Monitoring Mass Transport in Global Geophysical Fluids

    Science.gov (United States)

    Chao, Benjamin F.

    2004-01-01

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

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

    Science.gov (United States)

    Saribudak, By Mustafa; Hauwert, Nico M.

    2017-03-01

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

  9. ROMY: A 4-component large ring laser for geophysics

    Science.gov (United States)

    Igel, H.; Schreiber, K. U.; Gebauer, A.; Wassermann, J. M.; Lin, C. J.; Bernauer, F.; Simonelli, A.; Wells, J. P. R.

    2016-12-01

    Observatory-based ring lasers are currently the most sensitive technology for measurements of rotational ground motions (seismology) and variations of Earth's rotation rate. Ring laser have so far been limited to single components only (e.g., the horizontal G-ring in Wettzell, Germany, measuring the rotation around a vertical axis). Within the ROMY project (www.romy-erc.eu) funded by the European Research Council we designed and constructed the first multi-component ring laser system for geophysics. The 4-component, tetrahedral-shaped, top-down ring laser sits on a connected concrete structure embedded underground 2m below the surface at the Geophysical Observatory Fürstenfeldbruck, Germany. The 4 independent equilateral triangular-shaped He-Ne ring lasers with 12 m side length are expected to resolve rotational motions below 12 prad/s/sqrt(Hz). We will report on the design and construction process of this first-of-its-kind ring laser system, with completion expected in August 2016 by which time the optical systems are beginning to be assembled. The four rotational components are combined to the complete 3-component vector of Earth's rotation, perturbed by other geophysical signals such as earthquake induced ground motions, ocean-generated noise, Earth's free oscillations, interactions between atmosphere and solid Earth and other signals. First applications are expected in the field of seismology. We report on future plans to stabilize the ring geometry providing long-term stability for geodetic applications.

  10. Sensitivity of airborne geophysical data to sublacustrine permafrost thaw

    Directory of Open Access Journals (Sweden)

    B. J. Minsley

    2014-12-01

    Full Text Available A coupled hydrogeophysical forward and inverse modeling approach is developed to illustrate the ability of frequency-domain airborne electromagnetic (AEM data to characterize subsurface physical properties associated with sublacustrine permafrost thaw during lake talik formation. Several scenarios are evaluated that consider the response to variable hydrologic forcing from different lake depths and hydrologic gradients. The model includes a physical property relationship that connects the dynamic distribution of subsurface electrical resistivity based on lithology as well as ice-saturation and temperature outputs from the SUTRA groundwater simulator with freeze/thaw physics. Electrical resistivity models are used to simulate AEM data in order to explore the sensitivity of geophysical observations to permafrost thaw. Simulations of sublacustrine talik formation over a 1000 year period modeled after conditions found in the Yukon Flats, Alaska, are evaluated. Synthetic geophysical data are analyzed with a Bayesian Markov chain Monte Carlo algorithm that provides a probabilistic assessment of geophysical model uncertainty and resolution. Major lithological and permafrost features are well resolved in the examples considered. The subtle geometry of partial ice-saturation beneath lakes during talik formation cannot be resolved using AEM data, but the gross characteristics of sub-lake resistivity models reflect bulk changes in ice content and can be used to determine the presence of a talik. A final example compares AEM and ground-based electromagnetic responses for their ability to resolve shallow permafrost and thaw features in the upper 1–2 m below ground.

  11. Geological and geophysical methods for monitoring of heritage structures

    Science.gov (United States)

    Kulynych, Anna

    2017-04-01

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

  12. Bringing 3D Printing to Geophysical Science Education

    Science.gov (United States)

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

    2014-12-01

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

  13. Evaluation of a Geothermal Prospect Using a Stochastic Joint Inversion Algorithm

    Science.gov (United States)

    Tompson, A. F.; Mellors, R. J.; Ramirez, A.; Dyer, K.; Yang, X.; Trainor-Guitton, W.; Wagoner, J. L.

    2013-12-01

    A stochastic joint inverse algorithm to analyze diverse geophysical and hydrologic data for a geothermal prospect is developed. The purpose is to improve prospect evaluation by finding an ensemble of hydrothermal flow models that are most consistent with multiple types of data sets. The staged approach combines Bayesian inference within a Markov Chain Monte Carlo (MCMC) global search algorithm. The method is highly flexible and capable of accommodating multiple and diverse datasets as a means to maximize the utility of all available data to understand system behavior. An initial application is made at a geothermal prospect located near Superstition Mountain in the western Salton Trough in California. Readily available data include three thermal gradient exploration boreholes, borehole resistivity logs, magnetotelluric and gravity geophysical surveys, surface heat flux measurements, and other nearby hydrologic and geologic information. Initial estimates of uncertainty in structural or parametric characteristics of the prospect are used to drive large numbers of simulations of hydrothermal fluid flow and related geophysical processes using random realizations of the conceptual geothermal system. Uncertainty in the results is represented within a ranked subset of model realizations that best match all available data within a specified norm or tolerance. Statistical (posterior) characteristics of these solutions reflect reductions in the perceived (prior) uncertainties. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-641792.

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

    Science.gov (United States)

    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

  15. Geophysical techniques in the study of Hydrocarbon contamination: lab experiments

    Science.gov (United States)

    Giampaolo, Valeria; Rizzo, Enzo; Straface, Salvatore; Votta, Mario; Lapenna, Vincenzo

    2010-05-01

    Remediation of sites contaminated by hydrocarbon, due to blow out, leakage from tank or pipe and oil spill, is an environmental problem because infiltrated oil can persist in the ground for a long time and the actual method are invasive and expansive . In the last years there was a growing interest in the use of geophysical methods for environmental monitoring (Greenhouse et al., 1993; Daily and Ramirez, 1995; Lendvay et al., 1998; Atekwana et al., 2000; Chambers et al., 2004; Song et al., 2005; French et al., 2009), and there have been several recent study that relate self-potential measurements to subsurface contaminants (Perry et al., 1996; Naudet et al., 2003; Naudet et al., 2004). Infact, this method is a valid tool for site characterization and monitoring because it is sensitive to contaminant chemistry and redox processes generated by bacteria during the biodegradation phase (Atekwana et al., 2004; Naudet and Revil, 2005). Therefore the goal of this investigation is to characterize underground contaminant distributions using minimally invasive geophysical methods (electrical resistivity tomography and self-potential), in combination with hydrochemical measurements, and to develop fundamental constitutive relations between soil physical and degradation activity parameters and geophysically measurable parameters, in order to improve site remediation efficiency. These tests have been realized at a PVC pool situated in the Hydrogeosite Laboratory of CNR-IMAA. The pool is completely filled with ~ 0.80 m3 of an homogeneous medium (quartz-rich sand with a medium-high hydraulic conductivity in the order of 10-5 m/s), to simulate the space and time dynamics of an artificial aquifer; besides it has been endowed of a sensors network at surface and in borehole, to measure self-potential and electrical resistivity. The experiments consist in geophysical measurements to monitor a simulated oil spill into sand-box following by water rain. The experiment was able to obtain

  16. Critical zone architecture and processes: a geophysical perspective

    Science.gov (United States)

    Holbrook, W. S.

    2016-12-01

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

  17. Prospecting for coal in China with remote sensing

    Institute of Scientific and Technical Information of China (English)

    TAN Ke-long; WAN Yu-qing; SUN Sun-xin; BAO Gui-bao; KUANG Jing-shui

    2008-01-01

    With the rapid development of China's economy, coal resources are increasingly in great demand. As a result, the remaining coal reserves diminish gradually with large-scale exploitation of coal resources. Easily-found mines which used to be identiffed from outcrops or were buried under shallow overburden are decreasing, especially in the prosperous eastern regions of China,which experience coal shortages. Currently the main targets of coal prospecting are concealed and unidentified underground coal bodies, making it more and more difficult for coal prospecting. It is therefore important to explore coal prospecting by taking advantage of modern remote sensing and geographic information system technologies. Given a theoretical basis for coal prospecting by remote sensing, we demonstrate the methodologies and existing problems systematically by summarizing past practices of coal prospecting with remote sensing. We propose a new theory of coal prospecting with remote sensing. In uncovered areas, coal resources can be prospected for by direct interpretation. In coal beating strata of developed areas covered by thin Quaternary strata or vegetation, prospecting for coal can be carried out by indirect interpretation of geomorphology and vegetation. For deeply buried underground deposits, coal prospecting can rely on tectonic structures, interpretation and analysis of new tectonic clues and regularity of coal formation and preservation controlled by tectonic structures. By applying newly hyper-spectral, multi-polarization, multi-angle, multi-temporal and multi-resolution remote sensing data and carrying out integrated analysis of geographic attributes,ground attributes, geophysical exploration results, geochemical exploration results, geological drilling results and remote sensing data by GIS tools, coal geology resources and mineralogical regularities can be explored and coal resource information can be acquired with some confidence.

  18. First Paleomagnetic Map of the Easternmost Mediterranean Derived from Combined Geophysical-Geological Analysis

    Science.gov (United States)

    Eppelbaum, Lev; Katz, Youri

    2014-05-01

    he easternmost Mediterranean is a tectonically complex region evolving in the long term and located in the midst of the progressive Afro-Eurasian collision (e.g., Ben-Avraham, 1978; Khain, 1984). Both rift-oceanic systems and terrane belts are known to have been formed in this collision zone (Stampfli et al., 2013). Despite years of investigation, the geological-geophysical structure of the easternmost Mediterranean is not completely known. The formation of its modern complex structure is associated with the evolution of the Neotethys Ocean and its margins (e.g., Ben-Avraham and Ginzburg, 1990; Robertson et al., 1991; Ben-Avraham et al., 2002). The easternmost Mediterranean was formed during the initial phase of the Neotethys in the Early and Late Permian (Golonka and Ford, 2000; Stampfli et al., 2013). At present this block of the ocean crust situated in the northern part of the Sinai plate (Ben-Avraham, 1978; Eppelbaum et al., 2012, 2014) is object of our investigation. The easternmost Mediterranean region has attracted increasing attention in connection with the recent discoveries of significant hydrocarbon deposits in this region (e.g., Montadert et al., 2010; Schenk et al., 2010; Eppelbaum et al., 2012). For example, Schenk et al. (2010) consider that more than 4 trillion m3 of recoverable gas is available in the Levant Basin (which located in the central part of the easternmost Mediterranean). Currently seismic prospecting is the main tool used in hydrocarbon deposit discovery. However, even sophisticated seismic data analysis (e.g., Hall et al., 2005; Roberts and Peace, 2007; Gardosh et al., 2010; Marlow et al., 2011; Lazar et al., 2012), fails to identify the full complex structural-tectonic mosaic of this region, and more importantly, is unable to clarify its baffling complex tectonic evolution. This highlights the need for combined analysis of geophysical data associated with the paleomagnetic and paleobiogeographic conditions that can yield deep

  19. An application of geophysical techniques to the study of man-made cavities of historical importance

    Science.gov (United States)

    Pepe, Pietro; Martimucci, Vincenzo; Parise, Mario; Sammarco, Mariangela

    2010-05-01

    Geophysical techniques, based on different methodologies (Ground Penetrating Radar, electric tomography), are very useful to integrate the classical archaeological investigations, and may provide important results to be combined with other surveys. In this study, the geophysical prospections are applied aimed at gaining a better knowledge of a cultural heritage site in the inner part of Apulia region, in southern Italy. The study area is located near Altamura, in a rural area of the Murge plateau, and specifically in the immediate surroundings of Masseria Jesce (masseria is the typical countryside mansion in the region), which first settlement dates back to the end of 1500. There, five man-made cavities are present, two being located in front of the main facade of the mansion, whilst the remaining three are at its back. They are related to different activities carried out in the centuries at the site: from shelters for animals, to sites of production of milk and cheese, works for water collection and distribution, etc. All the man-made cavities are of high historical value but the most important is probably an hypogean crypt, site of christian worship, which walls are decorated with several frescoes dating back to the 14th century. Within the framework of a project dedicated to reach a better knowledge of the area, and to partial restoration of the site as well, geophysical techniques have been used in combination with direct speleological surveys to detect the known artificial caves, and to help in the identification of the probable, further ones. Main goal of the survey was in fact to obtain detailed information on the development and features of the underground cavities, and to verify their likely continuation. At Masseria Jesce the Ground Penetrating Radar (GPR) prospecting was carried out by means of a SIR20 GSSI system with GSSI 270 Mhz antenna, that provides a good compromise between resolution and depth of investigation. The data were subsequently processed

  20. Prospection in the area of Ajka-II colliery

    Energy Technology Data Exchange (ETDEWEB)

    Pera, F.; Toth, P.; Makrai, L.; Szentai, G.

    1987-01-01

    The recently operating coal mines of Ajka tend to be depleted and this fact demanded the prospection of another region. The exploration methods, aims are described. The complex exploration involved the drilling of 83 boreholes, the preparation of a gravity base map, the construction of seismic reflection and multi-frequency electromagnetic profiles, the well-hydraulic analyses, the quantitative gas analyses as well as some preliminary data on the rare element distribution in the coal seams. Based on the geological-geophysical result the region seems to have possibilities for about 50 years in the future.

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

    Science.gov (United States)

    Laplaige, Clement; Bossuet, Gilles; Thivet, Matthieu

    2010-05-01

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

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

    Science.gov (United States)

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

    2012-12-01

    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

  3. Confirming Ground Geophysical Survey for Mineralization in Al Bayda Area, Yemen

    Institute of Scientific and Technical Information of China (English)

    Faisal S. Al-Huzaim

    2003-01-01

    The Jabal Mabal-prospect of Al Bayda area is covered by meta-volcano sedimentary rocks. The importance of the study area comes from previous studies, which proved that the area has mineralization zones at the periphery of Jabal Al-Mabal. These mineralized zones lie along northwest-southeast shear zones, which occur inside the meta-volcanic rocks. The previous studies concluded that the mineralization was mostly associated with sulphides, especially at the reduction zones. These sulphides give a good response to electrical or electromagnetic techniques. The present study uses electrically induced polarization and Genie electromagnetic surveys to explore the extension of the mineralization zones at the subsurface. The self-potential (SP) technique shows numerous of mineralized zones. Most of these zones are distributed in the southern area along the contact between the quartz and gabbro. The induced polarization (IP) method has been applied on the selected profiles to delineate the subsurface contact between calcite, gabbro and quartz in Al-Jarra Valley and to calculate the shape and depth of the mineralization zones in the subsurface along these profiles. The Genie electromagnetic survey, which has been applied on selected profiles, delineated some weak mineralization occurrences corresponding to the shear zones. The integration of the results obtained using these three techniques, in addition to the different ground geophysical methods previously used, makes it possible to determine the most appropriate zones for development of exploration at the area of investigation.

  4. Non-invasive geophysical investigation and thermodynamic analysis of a palsa in Lapland, northwest Finland

    CERN Document Server

    Kohout, Tomáš; Rasmus, Kai; Leppäranta, Matti; Matero, Ilkka

    2014-01-01

    Non-invasive geophysical prospecting and a thermodynamic model were used to examine the structure, depth and lateral extent of the frozen core of a palsa near Lake Peeraj\\"arvi, in northwest Finland. A simple thermodynamic model verified that the current climatic conditions in the study area allow sustainable palsa development. A ground penetrating radar (GPR) survey of the palsa under both winter and summer conditions revealed its internal structure and the size of its frozen core. GPR imaging in summer detected the upper peat/core boundary, and imaging in winter detected a deep reflector that probably represents the lower core boundary. This indicates that only a combined summer and winter GPR survey completely reveals the lateral and vertical extent of the frozen core of the palsa. The core underlies the active layer at a depth of ~0.6 m and extends to about 4 m depth. Its lateral extent is ~15 m x ~30 m. The presence of the frozen core could also be traced as minima in surface temperature and ground condu...

  5. The Hydro Geophysical Investigation of Oyo State Industrial Estate Ogbomosho, Southwestern Nigeria Using Vertical Electrical Soundings

    Directory of Open Access Journals (Sweden)

    T.A. Adagunodo

    2013-02-01

    Full Text Available The aim of this research is to carry out hydro geophysical study of Oyo State industrial estate Ogbomosho with a view to determining the areas that are good for groundwater prospects and the areas that are not suitable for groundwater exploration. Vertical Electrical Sounding (VES method was used to map Oyo State industrial estate Ogbomosho which lies within latitude 08°06' 07.4" and 08°06' 25.4" North and longitude 004° 15' 03.3" and 004°15' 49.0" East of Southwestern Nigeria. Ten Vertical Electrical Soundings (VES were carried out across the area using the schlumberger electrode array configuration with current electrode separation (AB varying from 130 to 200 m. Nine out of the ten modeled curves were H-type where the remaining one was KH-type. The geoelectric sections obtained from the sounding curves revealed 3-layer and 4-layer earth models respectively. The models showed the subsurface layers categorized into the topsoil, weathered/clay, fractured layers and the fresh bedrock. The weathered basement and fractured basement are the aquifer types delineated for the area. Flow net and bedrock relief map showed that the Southern, Northeastern and towards the base of Northwestern direction of the study area are good for borehole development.

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

    Science.gov (United States)

    Xia, J.; Miller, R.D.

    2007-01-01

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

  7. Psychophysiology of prospective memory.

    Science.gov (United States)

    Rothen, Nicolas; Meier, Beat

    2014-01-01

    Prospective memory involves the self-initiated retrieval of an intention upon an appropriate retrieval cue. Cue identification can be considered as an orienting reaction and may thus trigger a psychophysiological response. Here we present two experiments in which skin conductance responses (SCRs) elicited by prospective memory cues were compared to SCRs elicited by aversive stimuli to test whether a single prospective memory cue triggers a similar SCR as an aversive stimulus. In Experiment 2 we also assessed whether cue specificity had a differential influence on prospective memory performance and on SCRs. We found that detecting a single prospective memory cue is as likely to elicit a SCR as an aversive stimulus. Missed prospective memory cues also elicited SCRs. On a behavioural level, specific intentions led to better prospective memory performance. However, on a psychophysiological level specificity had no influence. More generally, the results indicate reliable SCRs for prospective memory cues and point to psychophysiological measures as valuable approach, which offers a new way to study one-off prospective memory tasks. Moreover, the findings are consistent with a theory that posits multiple prospective memory retrieval stages.

  8. HVDC Ground Electrodes - a Source of Geophysical Data

    Science.gov (United States)

    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.

  9. Site Characterization of Deep Bedrock with Integrated Geophysical Survey

    Science.gov (United States)

    Son, J.; Kim, C.; Eun, S. B.

    2015-12-01

    In order to utilize the deep underground storage facility stable for a long time, precise site characterization is required before its construction. Various kinds of geophysical survey as well as drilling and geological survey should be used to know the status of deep bedrock. A research had been conducted to make the site characterization of deep bedrock for several years, and to achieve its purpose, integrated geophysical survey were applied to the test area which had gneiss bedrock. DC resistivity survey for six surficial profiles was conducted to find the appropriate location of drilling survey. Cross-hole/surface-to-hole resistivity tomography survey and borehole reflection radar survey were applied to the drill holes after its installation completed. Three bore holes of which length was 500 meter were drilled to investigate the status of deep bedrock, and cross-hole tomography survey was applied between two boreholes among these. Also borehole reflection radar survey was conducted to another two boreholes. Deep seated fracture zones which were not identified with the surficial geological and resistivity survey were found through the analysis of tomography section. Fracture zones were consisted of steep slope fault and these were also identified with the result of borehole radar section. After the basic survey was completed, one of three holes was extended to the depth of 1 km. Radar reflection survey which was only available to the deep drill-hole was applied. Because steel casing was installed to the depth of 750 m to stabilize the extended drill-hole, resistivity method was not available and borehole radar reflection method was only available among the geophysical method used in this research. Through results of radar reflection survey, several fracture zones were identified for the newly extended section of drill hole and some of those facture has relatively large size and passed through the bore hole.

  10. Improving Discoverability of Geophysical Data using Location Based Services

    Science.gov (United States)

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

    2014-12-01

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

  11. Estimating climate resilience for conservation across geophysical settings.

    Science.gov (United States)

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

    2014-08-01

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

  12. Geophysical characterization of Hydrogeological processes at the catchment scale

    Science.gov (United States)

    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).

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    Niederleithinger, E.

    2013-12-01

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

  15. Geophysical and geological investigations of the Boda area

    Energy Technology Data Exchange (ETDEWEB)

    Waenstedt, S. [Geosigma AB, Uppsala (Sweden)

    2000-04-15

    The studies conducted in the Boda area exhibit the presence of a severely fractured rock mass with occasional caves. The Boda area appears to be intersected by a few significant zones, obvious from a study of the topography but do appear in some of the geophysical investigations as well. The structures in the area have quite efficiently isolated the rock plint where the caves are located. It is not possible from these investigations, however, to draw far-reaching conclusions about the age and genesis of the zones or about their continuation towards depth. The geological investigation shows, apart from the caves, no unusual features. The rock types in the investigated area correspond with rock types found elsewhere in the region. The area is highly unsuitable for geophysical surface investigations. Part of the area consists of scattered and quite large blocks that constitute obstacles when making measurements in the area. Since there is little or no soil between the blocks some measurements (e.g. resistivity) are not possible to carry out. Furthermore, the scattered blocks cause unwanted reflections and other difficulties that deteriorate the quality of the geophysical data. The radar measurements with two different frequencies show an interesting result of importance not only to this investigation. The lower frequency appears to penetrate through the rocky overburden and is able to detect the soil-rock interface. The higher frequency is severely disturbed by the overburden but caves show much more clearly in this data. The fractured rock around Boda appears to be a shallow feature, since the radar measurements show a quite significant feature throughout most of the profiles, which appears to be the upper boundary of the bedrock. There are, however, some occasional strong reflectors below the interface between fractured and competent rock.

  16. Assessment of highway condition using combined geophysical surveys

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Fenglin Peng

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-01

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

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

    Science.gov (United States)

    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

  20. Lattice-Boltzmann Method for Geophysical Plastic Flows

    CERN Document Server

    Leonardi, Alessandro; Mendoza, Miller; Herrmann, Hans J

    2015-01-01

    We explore possible applications of the Lattice-Boltzmann Method for the simulation of geophysical flows. This fluid solver, while successful in other fields, is still rarely used for geotechnical applications. We show how the standard method can be modified to represent free-surface realization of mudflows, debris flows, and in general any plastic flow, through the implementation of a Bingham constitutive model. The chapter is completed by an example of a full-scale simulation of a plastic fluid flowing down an inclined channel and depositing on a flat surface. An application is given, where the fluid interacts with a vertical obstacle in the channel.

  1. Combination of Geophysical Methods to Support Urban Geological Mapping

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  4. The magnetic universe geophysical and astrophysical dynamo theory

    CERN Document Server

    Rüdiger, Günther

    2004-01-01

    Magnetism is one of the most pervasive features of the Universe, with planets, stars and entire galaxies all having associated magnetic fields. All of these fields are generated by the motion of electrically conducting fluids, the so-called dynamo effect. The precise details of what drives the motion, and indeed what the fluid consists of, differ widely though. In this work the authors draw upon their expertise in geophysical and astrophysical MHD to explore some of these phenomena, and describe the similarities and differences between different magnetized objects. They also explain why magn

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

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

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

    Science.gov (United States)

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

    2001-12-01

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

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

    Science.gov (United States)

    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.

  9. Genetic algorithms and smoothing filters in solving the geophysical inversion problem

    Directory of Open Access Journals (Sweden)

    Šešum Vesna

    2002-01-01

    Full Text Available The combination of genetic algorithms, smoothing filters and geophysical tomography is used in solving the geophysical inversion problem. This hybrid technique is developed to improve the results obtained by using genetic algorithm sonly. The application of smoothing filters can improve the performance of GA implementation for solving the geophysical inversion problem. Some test-examples and the obtained comparative results are presented.

  10. Simultaneous Estimation of Geophysical Parameters with Microwave Radiometer Data based on Accelerated Simulated Annealing: SA

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2012-07-01

    Full Text Available Method for geophysical parameter estimations with microwave radiometer data based on Simulated Annealing: SA is proposed. Geophysical parameters which are estimated with microwave radiometer data are closely related each other. Therefore simultaneous estimation makes constraints in accordance with the relations. On the other hand, SA requires huge computer resources for convergence. In order to accelerate convergence process, oscillated decreasing function is proposed for cool down function. Experimental results show that remarkable improvements are observed for geophysical parameter estimations.

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

    Science.gov (United States)

    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

  12. Integration of Field Geophysics and Geology in an International Setting: Multidisciplinary Geoscience Field Experience at the University of Western Ontario

    Science.gov (United States)

    Brenders, A. J.; Banerjee, N.; Pratt, R. G.

    2010-12-01

    The pedagogical value of the field experience is unequaled: students, teaching assistants, and professors alike return with a renewed sense of purpose, community, and the context in which to place classroom education. It is widely regarded as valuable to personal development, and is required by the Canadian Council of Professional Geoscientists for professional registration. As part of our ongoing International Geoscience Field Experience Initiative, Earth Sciences students at the University of Western Ontario have the opportunity to enhance their education through a study abroad program. The focus is on a residential field experience to world-class localities, offered with the collaboration of internationally recognized academic researchers, government survey personnel, and industry leaders. Recent trips have included the Sn-W mineralization in the Cornwall district of the U.K., the Iberian Pyrite Belt (IPB) in Portugal and Spain, and the metallogenic belts of Western Turkey. The integration of geological knowledge with geophysical data was one of the key organizing principles of our recent field trips to the IPB and Western Turkey. This integration is a foundation of modern Earth Sciences, and common practice in industry, it is relatively rare in classroom settings. Lectures before departure and evening exercises during the field trip supplemented the core undergraduate curriculum in geophysics, reviewing gravity, DC resistivity, induced polarization (IP), and magnetotelluric methods, focusing on application to mineral exploration. During our trip to the IPB, partnership with industry allowed students the opportunity to work with state of the art geophysical data, acquired on an exploration prospect visited during the field trip. Multi-parameter geophysical inversions of the IP and MT data produced cross-sections in depth - results interpretable by the students in the complex geological environment of the Iberian Pyrite Belt. Although the students gained valuable

  13. Comprehensive geophysics and lithosphenc structure in the western Xizang (Tibet) Plateau

    Institute of Scientific and Technical Information of China (English)

    孔祥儒; 王谦身; 熊绍柏

    1996-01-01

    Comprehensive investigations along the Gyirong-Lugu-Sangehu geophysical profile in the western Xizang Plateau are presented. Analysis and interpretation of the lithospheric structure resulted in setting up of the geophysical methods and marks for the division of tectonic units in the lithospheric structure. Comprehensive geophysical survey in the remote west of Xizang is reported and some reliable geophysical evidence for deep structure division in the study region is provided. These lay a solid basis for probing into the mechanism of the Xizang Plateau uplift and geodynamics.

  14. iSOIL: Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping

    Science.gov (United States)

    Dietrich, Peter; Werban, Ulrike; Sauer, Uta

    2010-05-01

    High-resolution soil property maps are one major prerequisite for the specific protection of soil functions and restoration of degraded soils as well as sustainable land use, water and environmental management. To generate such maps the combination of digital soil mapping approaches and remote as well as proximal soil sensing techniques is most promising. However, a feasible and reliable combination of these technologies for the investigation of large areas (e.g. catchments and landscapes) and the assessment of soil degradation threats is missing. Furthermore, there is insufficient dissemination of knowledge on digital soil mapping and proximal soil sensing in the scientific community, to relevant authorities as well as prospective users. As one consequence there is inadequate standardization of techniques. At the poster we present the EU collaborative project iSOIL within the 7th framework program of the European Commission. iSOIL focuses on improving fast and reliable mapping methods of soil properties, soil functions and soil degradation risks. This requires the improvement and integration of advanced soil sampling approaches, geophysical and spectroscopic measuring techniques, as well as pedometric and pedophysical approaches. The focus of the iSOIL project is to develop new and to improve existing strategies and innovative methods for generating accurate, high resolution soil property maps. At the same time the developments will reduce costs compared to traditional soil mapping. ISOIL tackles the challenges by the integration of three major components: (i)high resolution, non-destructive geophysical (e.g. Electromagnetic Induction EMI; Ground Penetrating Radar, GPR; magnetics, seismics) and spectroscopic (e.g., Near Surface Infrared, NIR) methods, (ii)Concepts of Digital Soil Mapping (DSM) and pedometrics as well as (iii)optimized soil sampling with respect to profound soil scientific and (geo)statistical strategies. A special focus of iSOIL lies on the

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

    Science.gov (United States)

    Nesterenko, A.

    2013-05-01

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

  16. Safety in GPR prospecting: a rarely-considered issue

    Science.gov (United States)

    Persico, Raffaele; Pajewski, Lara; Trela, Christiane; Carrick Utsi, Erica

    2016-04-01

    Safety issues (of people first of all, but also of the equipment and environment) are rarely considered in Ground-Penetrating Radar (GPR) prospecting and, more in general, in near-surface geophysical prospecting. As is right and fully understandable, the scientific community devotes greatest attention first of all to the theoretical and practical aspects of GPR technique, affecting the quality of attainable results, secondly to the efforts and costs needed to achieve them [1-2]. However, the (luckily) growing GPR market and range of applications make it worth giving serious consideration to safety issues, too. The existing manuals dealing with safety in geophysics are mainly concerned with applications requiring "deep" geophysical prospecting, for example the search for oilfields and other hydrocarbon resources [3]. Near-surface geophysics involves less dangers than deep geophysics, of course. Nevertheless, several accidents have already happened during GPR experimental campaigns. We have personally had critical experiences and collected reliable testimonies concerning occurred problems as mountain sicks, fractures of legs, stomach problems, allergic reactions, encounters with potentially-dangerous animals, and more. We have also noticed that much more attention is usually paid to safety issues during indoor experimental activities (in laboratory), rather than during outdoor fieldworks. For example, the Italian National research Council is conventioned with safety experts who hold periodical seminaries about safety aspects. Having taken part to some of them, to our experience we have never heard a "lecture" devoted to outdoor prospecting. Nowadays, any aspects associated to the use of the technologies should be considered. The increasing sensibility and sense of responsibility towards environmental matters impose GPR end-users to be careful not to damage the environment and also the cultural heritage. Near-surface prospecting should not compromise the flora and

  17. Coal quality estimation using geophysical logging without radioactive sources

    Energy Technology Data Exchange (ETDEWEB)

    Beretta, F.; De Souza, V.C.G.; Salvadoretti, P.; Costa, J.F.C.L.; Koppe, J.C. [Univ. Federal do Rio Grando do Sul, Rio Grando do Sul (Brazil). Dept. of Mining Engineering; Bastiani, G.A.; Carvalho, J.A.Jr. [Copelmi Mineracao, Rio Grando do Sul (Brazil)

    2009-07-01

    Drill hole logging is widely used in mining and mineral exploration to determine the physical and chemical properties of ore. Geophysical probes are used to delineate coal seams and measure coal seam density. Gamma-gamma logging of the seams is used to determine correlations in ash content and coal density. This study evaluated the accuracy of geophysical logging techniques in predicting coal quality. Seventeen holes in the study were drilled in an irregular grid with spaces ranging from 200 to 600 m. The average recorded values of natural gamma and the resistivity from the logs were obtained. Differences between the coal seams in the deposit were analyzed statistically. The study showed a strong correlation between natural gamma and ash content in the deposit. Relative errors were approximately 10 per cent for a confidence interval of 99.99 per cent. It was concluded that natural gamma logging can be used to accurately measure the ash content in coal seams. 19 refs., 2 tabs., 3 figs.

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

    CERN Document Server

    Tarling, D H

    1983-01-01

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

  19. From Geophysics to Microgeophysics for Engineering and Cultural Heritage

    Directory of Open Access Journals (Sweden)

    P. L. Cosentino

    2011-01-01

    Full Text Available The methodologies of microgeophysics have been derived from the geophysical ones, for the sake of solving specific diagnostic and/or monitoring problems regarding civil engineering and cultural heritage studies. Generally, the investigations are carried out using different 2D and 3D tomographic approaches as well as different energy sources: sonic and ultrasonic waves, electromagnetic (inductive and impulsive sources, electric potential fields, and infrared emission. Many efforts have been made to modify instruments and procedures in order to improve the resolution of the surveys as well as to significantly reduce the time of the measurements without any loss of information. This last point has been achieved by using multichannel systems. Finally, some applications are presented, and the results seem to be very promising and promote this new branch of geophysics. Therefore, these methodologies can be used even more to diagnose, monitor, and safeguard not only engineering buildings and/or large structures, but also ancient monuments and cultural artifacts, such as pottery, statues, and so forth.

  20. Integrated geophysical surveys on railroads in permafrost areas

    Institute of Scientific and Technical Information of China (English)

    A Ivanov; S Klepikova; M Shirobokov; A Urusova; A Savin

    2013-01-01

    The zones of thawed ground in the permafrost area are most dangerous from engineer-geologist effect point of view. Detection of such zones, as making forecast of their movement is the main task of engineer-geologist survey been held in railway industry. This paper presents general issues concerning railway construction and operation in permafrost areas. Comprehensive geophysical methods to monitor the development of thawed soils are considered in detail. The main physical parameters which help define permafrost and thawed soil patches are described. Author of current paper pointed out main factors, allowing predicting potential areas of development of thawed grounds. They offered set non-destructive methods:GPR investigations, seismic survey and elec-tric exploration. Whole sets of geophysical data:electric resistivity, velocity of S-wave and P-wave (and their correlation), allow us with high confidence specify characteristics and state of soil either under the line of road, or near it. At the same time the meth-od allows to predict direction of further development of thawed ground area.

  1. Using airborne geophysical surveys to improve groundwater resource management models

    Science.gov (United States)

    Abraham, Jared D.; Cannia, James C.; Peterson, Steven M.; Smith, Bruce D.; Minsley, Burke J.; Bedrosian, Paul A.

    2010-01-01

    Increasingly, groundwater management requires more accurate hydrogeologic frameworks for groundwater models. These complex issues have created the demand for innovative approaches to data collection. In complicated terrains, groundwater modelers benefit from continuous high‐resolution geologic maps and their related hydrogeologic‐parameter estimates. The USGS and its partners have collaborated to use airborne geophysical surveys for near‐continuous coverage of areas of the North Platte River valley in western Nebraska. The survey objectives were to map the aquifers and bedrock topography of the area to help improve the understanding of groundwater‐surface‐water relationships, leading to improved water management decisions. Frequency‐domain heliborne electromagnetic surveys were completed, using a unique survey design to collect resistivity data that can be related to lithologic information to refine groundwater model inputs. To render the geophysical data useful to multidimensional groundwater models, numerical inversion is necessary to convert the measured data into a depth‐dependent subsurface resistivity model. This inverted model, in conjunction with sensitivity analysis, geological ground truth (boreholes and surface geology maps), and geological interpretation, is used to characterize hydrogeologic features. Interpreted two‐ and three‐dimensional data coverage provides the groundwater modeler with a high‐resolution hydrogeologic framework and a quantitative estimate of framework uncertainty. This method of creating hydrogeologic frameworks improved the understanding of flow path orientation by redefining the location of the paleochannels and associated bedrock highs. The improved models reflect actual hydrogeology at a level of accuracy not achievable using previous data sets.

  2. Geophysical Techniques for Monitoring CO2 Movement During Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Chronology of petroleum geophysics; Sekiyu butsuri tansa nenpyo

    Energy Technology Data Exchange (ETDEWEB)

    Kametani, T.

    1996-10-01

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

  4. Geophysical investigation of a mineral groundwater resource in Turkey

    Science.gov (United States)

    Boiero, Daniele; Godio, Alberto; Naldi, Mario; Yigit, Ercan

    2010-08-01

    The hydrogeological conditions in Uludag (Nilufer River catchment, Bursa, Turkey) were assessed, using time-domain electromagnetic soundings, electrical resistivity and induced polarisation tomography, to detect the most promising zones for new water-well siting, in order to increase the quantity of water for bottling. The hydrogeological model is quite complex: deep mineral and thermal water rises from a main vertical fault which separates two lithological complexes. The highly mineralised (deep) water is naturally mixed with low mineralised water at a shallow depth, 30-40 m; the mixed mineral water is found in some surface springs and shallow wells, while the highly mineralised water is found at depth in some unused deep wells located close to the main fault. All the water points (springs and wells) are located inside a “mineral water belt” on the north side of the Nilufer River. The geophysical survey confirmed the hydrogeological model and highlighted four promising zones for well siting (zones with very low electrical resistivity and high induced polarisation anomalies, corresponding to the main water-bearing faults). One of the geophysical anomalies, the furthest from the exploited sources, was verified by means of a test well; the drilling results have confirmed the water mixing model.

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

    Science.gov (United States)

    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.

  6. Shallow geophysical investigations at the Akhmim archaeological site, Suhag, Egypt

    Science.gov (United States)

    Hafez, Mahfooz A.; Atya, Magdy A.; Hassan, Azza M.; Sato, Motoyuki; Wonik, Thomas; El-Kenawy, Abeer A.

    2008-06-01

    Ground penetrating radar, electromagnetic terrain conductivity, and electric tomography have proven to be effective tools if they are combined together to investigate archeological sites. We have conducted a geophysical survey at the Akhmim archaeological site, the main objective of our survey is to locate additional buried structures for further excavation. Geophysical data were acquired in the area using the GEM-300 multi-frequency terrain conductivity profiler, the SIR 2000 ground penetrating radar, and the Syscal R2 resistivity meter systems. The results of the integrated interpretation show a number of buried features and a strong linear zone about 1 m wide that coincides with the suspected trend of a buried wall. There appears to be two parallel ridges of strong reflections on either side, indicating two parallel walls extended East-West and a room is identified at the bottom left corner of the site. Moreover, the interpretation results of some selected GPR and dipoledipole resistivity profiles adjacent to the open-air museum suggest the existence of a second statue of Ramses II to the right of the previously discovered statue which could still be buried in the sand.

  7. Geophysics and the search of freshwater bodies: a review.

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  9. High-resolution Geophysical Mapping of Submarine Glacial Landforms

    Science.gov (United States)

    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.

  10. Beyond multifractional Brownian motion: new stochastic models for geophysical modelling

    Directory of Open Access Journals (Sweden)

    J. Lévy Véhel

    2013-09-01

    Full Text Available Multifractional Brownian motion (mBm has proved to be a useful tool in various areas of geophysical modelling. Although a versatile model, mBm is of course not always an adequate one. We present in this work several other stochastic processes which could potentially be useful in geophysics. The first alternative type is that of self-regulating processes: these are models where the local regularity is a function of the amplitude, in contrast to mBm where it is tuned exogenously. We demonstrate the relevance of such models for digital elevation maps and for temperature records. We also briefly describe two other types of alternative processes, which are the counterparts of mBm and of self-regulating processes when the intensity of local jumps is considered in lieu of local regularity: multistable processes allow one to prescribe the local intensity of jumps in space/time, while this intensity is governed by the amplitude for self-stabilizing processes.

  11. Utilization of remote sensing methods in prospecting of alkaline rocks in Finland and neighbouring areas

    Directory of Open Access Journals (Sweden)

    Paarma, H.

    1996-06-01

    Full Text Available The availability of various kind of satellite imageries and geological, geochemical and geophysical data in useful form has given possibility to confirm the earlier tectonic interpretations of deep fracture zones and to find new interesting zones for the exploring of alkaline rocks in Finland. The interpretations and suggestions given here are tentative prognoses for prospecting certain areas. The selecting of real target areas need more work. Some methods for this kind of classifying research for planning prospecting projects have been recommended. So far the Finnish Lapland is regarded as a region where the methods suggested here would give useful results.

  12. Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect

    Energy Technology Data Exchange (ETDEWEB)

    Frary, R.; Louie, J. [UNR; Pullammanappallil, S. [Optim; Eisses, A.

    2016-08-01

    Roxanna Frary, John N. Louie, Sathish Pullammanappallil, Amy Eisses, 2011, Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract T13G-07.

  13. Geophysical characterisation of a rockslide in an alpine region

    Science.gov (United States)

    Godio, A.; de Bacco, G.; Strobbia, C.

    2003-04-01

    The rock slope stability analysis requires the geomechanical characterisation of the different geological units that may be affected by the instability, and hence the required investigation depth depends on the mechanism of the movement and on its scale. A joint application of laboratory test and in situ extensive geophysical investigation has been used for the geological and geotechnical characterisation of a site with heavy slope and interested by recent events of landslide in the overburden and rockslide. An existing road is going to be substituted by a tunnel, and so both the shallow detritical overburden and the rock mass has to be investigated. The geophysical survey has been planned taking into account the difficult logistical condition of the area; the accessibility also conditioned the positioning of the boreholes. Two horizontal boreholes, each 50 m long, were drilled along the designed tunnel line, and two vertical boreholes, 30m of depth, were realised in order to take samples to test for the estimate of the mechanical properties of the rock mass. They also provided direct punctual information on the thickness of the overburden and allowed to calibrate the geophysical results. The horizontal ones have been used for borehole seismic and for ultrasonic logging; in the vertical ones inclinometers have been installed to monitor the movements. The stratigraphic evidence showed the presence of shallow layer of low-consolidated materials and a hard gneissic bedrock around 20 m deep. Laboratory measurements on samples allowed the determination of the high-strain mechanical behaviour and the dynamic low-strain elastic moduli (P and S wave ultrasonic pulse test). These data are compared with the results of the in situ characterisation: the geophysical investigation had to answer a series of questions about the geometry and the properties of the detritical overburden, the inhomogeneities and the fracture distribution of the rock mass, the eventual presence of

  14. Estimating the Prospectivity of Geothermal Resources Using the Concept of Hydrogeologic Windows

    Science.gov (United States)

    Bielicki, Jeffrey; Blackwell, David; Harp, Dylan; Karra, Satish; Kelley, Richard; Kelley, Shari; Middleton, Richard; Person, Mark; Sutula, Glenn; Witcher, James

    2016-04-01

    In this Geothermal Play Fairways Analysis project we sought to develop new ways to analyze geologic, geochemical, and geophysical data to reduce the risk and increase the prospects of successful geothermal exploration and development. We collected, organized, and analyzed data from southwest New Mexico in the context of an integrated framework that combines the data for various signatures of a geothermal resource into a cohesive analysis of the presence of heat, fluid, and permeability. We incorporated data on structural characteristics (earthquakes, geophysical logs, fault location and age, basement depth), topographic and water table elevations, conservative ion concentrations, and thermal information (heat flow, bottom hole temperature, discharge temperature, and basement heat generation). These data were combined to create maps that indicate structural analysis, slope, geothermometry, and heat. We also mapped discharge areas (to constrain elevations where groundwater may be discharged through modern thermal springs or paleo-thermal springs) and subcrops: possible erosionally- or structurally-controlled breaches in regional-scale aquitards that form the basis of our hydrogeologic windows concept. These two maps were particularly useful in identifying known geothermal systems and narrowing the search for unknown geothermal prospects. We further refined the "prospectivity" of the areas within the subcrops and discharge areas by developing and applying a new method for spatial association analysis to data on known and inferred faults, earthquakes, geochemical thermometers, and heat flow. This new methodology determines the relationships of the location and magnitudes of observations of these data with known geothermal sites. The results of each of the six spatial association analyses were weighted between 0 and 1 and summed to produce a prospectivity score between 0 and 6, with 6 indicating highest geothermal potential. The mean value of prospectivity for all

  15. Joint Inversion Modelling of Geophysical Data From Lough Neagh Basin

    Science.gov (United States)

    Vozar, J.; Moorkamp, M.; Jones, A. G.; Rath, V.; Muller, M. R.

    2015-12-01

    Multi-dimensional modelling of geophysical data collected in the Lough Neagh Basin is presented in the frame of the IRETHERM project. The Permo-Triassic Lough Neagh Basin, situated in the southeastern part of Northern Ireland, exhibits elevated geothermal gradient (~30 °C/km) in the exploratory drilled boreholes. This is taken to indicate good geothermal exploitation potential in the Sherwood Sandstone aquifer for heating, and possibly even electricity production, purposes. We have used a 3-D joint inversion framework for modelling the magnetotelluric (MT) and gravity data collected to the north of the Lough Neagh to derive robust subsurface geological models. Comprehensive supporting geophysical and geological data (e.g. borehole logs and reflection seismic images) have been used in order to analyze and model the MT and gravity data. The geophysical data sets were provided by the Geological Survey of Northern Ireland (GSNI). Considering correct objective function weighting in favor of noise-free MT response functions is particularly important in joint inversion. There is no simple way how to correct distortion effects the 3-D responses as can be done in 1-D or 2-D case. We have used the Tellus Project airborne EM data to constrain magnetotelluric data and correct them for near surface effects. The shallow models from airborne data are used to constrain the uppermost part of 3-D inversion model. Preliminary 3-D joint inversion modeling reveals that the Sherwood Sandstone Group and the Permian Sandstone Formation are imaged as a conductive zone at the depth range of 500 m to 2000 m with laterally varying thickness, depth, and conductance. The conductive target sediments become shallower and thinner to the north and they are laterally continuous. To obtain better characterization of thermal transport properties of investigated area we used porosity and resistivity data from the Annaghmore and Ballymacilroy boreholes to estimate the relations between porosity

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

    Science.gov (United States)

    Abedi, Maysam; Norouzi, Gholam-Hossain

    2016-04-01

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

  17. Magnetometry and archaeological prospection in Mexico

    Science.gov (United States)

    Barba Pingarron, L.; Laboratorio de Prospeccion Arqueologica

    2013-05-01

    Luis Barba Laboratorio de Prospección Arqueológica Instituto de Investigaciones Antropológicas Universidad Nacional Autonoma de México The first magnetic survey in archaeological prospection was published in 1958 in the first number of Archaeometry, in Oxford. That article marked the beginning of this applications to archaeology. After that, magnetic field measurements have become one of the most important and popular prospection tools. Its most outstanding characteristic is the speed of survey that allows to cover large areas in short time. As a consequence, it is usually the first approach to study a buried archaeological site. The first attempts in Mexico were carried out in 196. Castillo and Urrutia, among other geophysical techniques, used a magnetometer to study the northern part of the main plaza, zocalo, in Mexico City to locate some stone Aztec sculptures. About the same time Morrison et al. in La Venta pyramid used a magnetometer to measure total magnetic field trying to find a substructure. Some years later Brainer and Coe made a magnetic survey to locate large stone Olmec heads in San Lorenzo Tenochtitlan, Veracruz. Technology development has provided everyday more portable and accurate instruments to measure the magnetic field. The first total magnetic field proton magnetometers were followed by differential magnetometers and more recently gradiometers. Presently, multiple sensor magnetometers are widely used in European archaeology. The trend has been to remove the environmental and modern interference and to make more sensitive the instruments to the superficial anomalies related to most of the archaeological sites. There is a close relationship between the geology of the region and the way magnetometry works in archaeological sites. Archaeological prospection in Europe usually needs very sensitive instruments to detect slight magnetic contrast of ditches in old sediments. In contrast, volcanic conditions in Mexico produce large magnetic contrast

  18. The application of geophysics in South African coal mining and exploration

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2014-10-01

    Full Text Available in-house geophysicists. Consequently, the Coaltech Research Organisation’s Geology and Geophysics working group forum compiled a textbook aimed at addressing this need: to produce a guide for applying geophysics to coal mining problems in South Africa...

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

    Science.gov (United States)

    Sharman, George F.; Metzger, Dan

    1992-01-01

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

  20. High resolution land surface geophysical parameters estimation from ALOS PALSAR data

    Science.gov (United States)

    High resolution land surface geophysical products, such as soil moisture, surface roughness and vegetation water content, are essential for a variety of applications ranging from water management to regional climate predictions. In India high resolution geophysical products, in particular soil moist...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bergstrom, K.A.

    1993-10-01

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

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

    Science.gov (United States)

    American Geophysical Union, Washington, DC.

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

  3. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Science.gov (United States)

    2010-01-01

    ... COMMERCE GENERAL REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE ENVIRONMENTAL DATA AND INFORMATION § 950.5...-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 physics...

  4. Protoplanetary Earth Formation: Further Evidence and Geophysical Implications

    CERN Document Server

    Herndon, J M

    2004-01-01

    Recently, I showed that the "standard model" of solar system formation is wrong,yielding the contradiction of terrestrial planets having insufficiently massive cores, and showed instead the consistency of Eucken's 1944 concept of planets raining out in the central regions of hot, gaseous protoplanets. Planets generally consist of concentric shells of matter, but there has been no adequate geophysical explanation to account for the Earth's non-contiguous crustal continental rock layer, except by assuming that the Earth in the distant past was smaller and subsequently expanded. Here, I show that formation of Earth, from within a Jupiter-like protoplanet, will account for the compression of the rocky Earth to about 64 percent of its current radius, yielding a closed, contiguous continental shell with concomitant Earth expansion commencing upon the subsequent removal of its protoplanetary gaseous shell. I now propose that Earth expansion progresses, not from spreading at mid-oceanic ridges as usually assumed, but...

  5. The Dynamics of Flat Surface Internal Geophysical Waves with Currents

    Science.gov (United States)

    Compelli, Alan; Ivanov, Rossen I.

    2016-08-01

    A two-dimensional water wave system is examined consisting of two discrete incompressible fluid domains separated by a free common interface. In a geophysical context this is a model of an internal wave, formed at a pycnocline or thermocline in the ocean. The system is considered as being bounded at the bottom and top by a flatbed and wave-free surface respectively. A current profile with depth-dependent currents in each domain is considered. The Hamiltonian of the system is determined and expressed in terms of canonical wave-related variables. Limiting behaviour is examined and compared to that of other known models. The linearised equations as well as long-wave approximations are presented.

  6. Geophysical Investigations for Groundwater in Outita, Morroco, using ERT Method

    Directory of Open Access Journals (Sweden)

    Latifa Ouadif

    2014-01-01

    Full Text Available Morocco is a country in semi-arid to arid climate. Rainfall is irregular in time and space. Surface water undergoes very large fluctuations due to the hydraulicity of the year. Hence, the use of groundwater resources that play a very important role in supplying water to rural populations and irrigation. In this context a geophysical survey was carried out in Outita. The interpretation of ERT profiles oriented West-East showed a horst and graben structure and revealed the existence of water-bearing formations at depths of around 300m. To determine the lateral extent of these formations, two ERT profiles oriented in the North-South direction were carried out.

  7. Mathematical model of MMR inversion for geophysical data

    Directory of Open Access Journals (Sweden)

    Suabsagun Yooyuanyong

    2007-09-01

    Full Text Available In this paper, we present an analysis of the solution to a number of geophysical inverse problems which are generally non-unique. The mathematical inverse problem that arises is commonly ill-posed in the sense that small changes in the data lead to large changes in the solution. We conduct the inversion algorithm to explore the conductivity for the ground structure. The algorithm uses the data in the form of magnetic field measurements for magnetometric resistivity (MMR. The inversion example is performed to investigate the conductivity ground profile that best fits the observed data. The result is compared with the true model and discussed to show the efficiency of the method. The model for the inversion example with the apparent conductivity and the true conductivity are plotted to show the convergence of the algorithm.

  8. Experimental analysis of the levees safety based on geophysical monitoring

    Science.gov (United States)

    Rizzo, Enzo; Valeria, Giampaolo; Mario, Votta; Lapenna, Vincenzo; Moramarco, Tommaso; Aricò, Costanza; Camici, S.; Morbidelli, Renato; Sinagra, M.; Tucciarelli, T.

    2010-05-01

    Several flood events brought river levees into the focus of attention for some disasters due to their collapse. This phenomena is quite complex to investigate, because of different factors that can affect the stability of levees, among them the non uniformity of material properties, which influencing the permeability of the embankment, might induce high percolation velocity of flux thus triggering the unstability. Thus, to apply a fast and integrate investigation methods with a non-destructive characteristics should have a large interest, if they are able to furnish ready and usable information necessary to hydrogeological models. In order to achieve this goal, the University of Perugia (Department of Civil and Environmental Engineering) and the National Research Council (IRPI and IMAA research institutes) developed a collaborating project on the study of the internal structure of the river embankment by carrying out experiments in laboratory. The purpose of this study is to show the preliminary results of the experimental investigation. The laboratory embankment was built using material coming from a real levee and gathered inside a 1.5m x 1.2m plexiglas box. The box has two compartments: a water reservoir at one hand where a constant water head was reached after some time and a soil simulating the presence of levee. We perform a geoelectrical multichannel acquisition system with three parallel profiles characterized by 16 mini-electrodes connected to georesistivimeter Syscal Pro. An automatic acquisition protocol has been performed to obtain time slice electrical tomographies during the experiments. The geophysical results show the effect of the water table inside the embankment during the wetting and emptying. In order to assess the capability of the geophysical monitoring for addressing the soil parameters estimate, the resistivity results are investigated by using two analytical and one hydraulic numerical models. The analytical models represent a linear

  9. Proposed geologic model based on geophysical well logs

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-01-01

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

  10. Wavelet correlations to reveal multiscale coupling in geophysical systems

    CERN Document Server

    Casagrande, Erik; Miralles, Diego; Entekhabi, Dara; Molini, Annalisa

    2015-01-01

    The interactions between climate and the environment are highly complex. Due to this complexity, process-based models are often preferred to estimate the net magnitude and directionality of interactions in the Earth System. However, these models are based on simplifications of our understanding of nature, thus are unavoidably imperfect. Conversely, observation-based data of climatic and environmental variables are becoming increasingly accessible over large scales due to the progress of space-borne sensing technologies and data-assimilation techniques. Albeit uncertain, these data enable the possibility to start unraveling complex multivariable, multiscale relationships if the appropriate statistical methods are applied. Here, we investigate the potential of the wavelet cross-correlation method as a tool for identifying multiscale interactions, feedback and regime shifts in geophysical systems. The ability of wavelet cross-correlation to resolve the fast and slow components of coupled systems is tested on syn...

  11. Geophysical constraints on geodynamical processes at convergent margins

    DEFF Research Database (Denmark)

    Artemieva, Irina; Thybo, Hans; Shulgin, Alexey

    2016-01-01

    Convergent margins, being the boundaries between colliding lithospheric plates, form the most disastrous areas in the world due to intensive, strong seismicity and volcanism. We review global geophysical data in order to illustrate the effects of the plate tectonic processes at convergent margins...... on the crustal and upper mantle structure, seismicity, and geometry of subducting slab. We present global maps of free-air and Bouguer gravity anomalies, heat flow, seismicity, seismic Vs anomalies in the upper mantle, and plate convergence rate, as well as 20 profiles across different convergent margins....... A global analysis of these data for three types of convergent margins, formed by ocean-ocean, ocean-continent, and continent-continent collisions, allows us to recognize the following patterns. (1) Plate convergence rate depends on the type of convergent margins and it is significantly larger when...

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

    Energy Technology Data Exchange (ETDEWEB)

    1988-05-01

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

  13. Statistical mechanics of two-dimensional and geophysical flows

    CERN Document Server

    Bouchet, Freddy

    2011-01-01

    The theoretical study of the self-organization of two-dimensional and geophysical turbulent flows is addressed based on statistical mechanics methods. This review is a self-contained presentation of classical and recent works on this subject; from the statistical mechanics basis of the theory up to applications to Jupiter's troposphere and ocean vortices and jets. Emphasize has been placed on examples with available analytical treatment in order to favor better understanding of the physics and dynamics. The equilibrium microcanonical measure is built from the Liouville theorem. On this theoretical basis, we predict the output of the long time evolution of complex turbulent flows as statistical equilibria. This is applied to make quantitative models of two-dimensional turbulence, the Great Red Spot and other Jovian vortices, ocean jets like the Gulf-Stream, and ocean vortices. We also present recent results for non-equilibrium situations, for the studies of either the relaxation towards equilibrium or non-equi...

  14. High-resolution geophysical characterization of shallow-water wetlands

    DEFF Research Database (Denmark)

    Mansoor, N; Slater, L; Artigas, F

    2006-01-01

    We describe a procedure for rapid characterization ofshallow-water, contaminated wetlands. Terrain-conductivityTC, vertical-magnetic-gradiometry, and surface-waterchemistrydata were obtained from a shallow-draft paddleboatoperable in as little as 0.3 m of water. Measurementswere taken every 2 s......, with data-acquisition rates exceeding10 km of line 12 000 data points per 8-hr field day.We applied this procedure to an urban wetland that is affectedby point and nonpoint sources of pollution.We used aone-dimensional, laterally constrained inversion algorithmto invert the apparent-conductivity data set...... as lithologiclogs from across the wetland, to constrain interpretation ofthe geophysical data. The inverted sediment conductivity describesa pattern of contamination probably attributable toleachates from adjacent landfills and/or to saltwater ingressfrom a partial tidal connection that is not obvious...

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

    CERN Document Server

    Khan, Amir

    2015-01-01

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

  16. Coastal geophysical data collected in 2016 nearshore Cape Canaveral, Florida

    Science.gov (United States)

    Buster, Noreen A.; Miselis, Jennifer L.; Okano, Shinobu; Gayes, Paul T.; Hill, Jenna C.

    2017-01-01

    Geophysical data including multibeam bathymetry and backscatter, side scan sonar, and chirp subbottom were collected by Coastal Carolina University (CCU) Center for Marine and Wetland Studies (CMWS), Conway, South Carolina, in June 2016 in collaboration with the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) in the nearshore environment of Cape Canaveral, Florida. The goal of the effort was to broadly characterize the geology of the shelf to identify spatial linkages with previously measured coastal change and bathymetric variability (https://pubs.er.usgs.gov/publication/ofr20151180). This USGS Data Release includes the: 1) processed elevation point data (xyz) and digital elevation model (DEM), 2) processed images of backscatter and side scan sonar (SSS), and 3) chirp subbottom profile data (segy and jpg). For further information regarding data collection and/or processing please see the metadata associated with this data release.

  17. The Dynamics of Flat Surface Internal Geophysical Waves with Currents

    CERN Document Server

    Compelli, Alan

    2016-01-01

    A two-dimensional water wave system is examined consisting of two discrete incompressible fluid domains separated by a free common interface. In a geophysical context this is a model of an internal wave, formed at a pycnocline or thermocline in the ocean. The system is considered as being bounded at the bottom and top by a flatbed and wave-free surface respectively. A current profile with depth-dependent currents in each domain is considered. The Hamiltonian of the system is determined and expressed in terms of canonical wave-related variables. Limiting behaviour is examined and compared to that of other known models. The linearised equations as well as long-wave approximations are presented.

  18. Geophysical Aspects of Non-Newtonian Fluid Mechanics

    Science.gov (United States)

    Balmforth, N. J.; Craster, R. V.

    Non-Newtonian fluid mechanics is a vast subject that has several journals partly, or primarily, dedicated to its investigation (Journal of Non-Newtonian Fluid Mechanics, Rheologica Acta, Journal of Fluid Mechanics, Journal of Rheology, amongst others). It is an area of active research, both for industrial fluid problems and for applications elsewhere, notably geophysically motivated issues such as the flow of lava and ice, mud slides, snow avalanches and debris flows. The main motivati on for this research activity is that, apart from some annoyingly common fluids such as air and water, virtually no fluid is actually Newtonian (that is, having a simple linear relation between stress and strain-rate characterized by a constant viscosity). Several textbooks are useful sources of information; for example, [1-3] are standard texts giving mathematical and engineering perspectives upon the subject. In these lecture notes, Ancey's chapter on rheology (Chap. 3) gives further introduction.

  19. Deterministic treatment of model error in geophysical data assimilation

    CERN Document Server

    Carrassi, Alberto

    2015-01-01

    This chapter describes a novel approach for the treatment of model error in geophysical data assimilation. In this method, model error is treated as a deterministic process fully correlated in time. This allows for the derivation of the evolution equations for the relevant moments of the model error statistics required in data assimilation procedures, along with an approximation suitable for application to large numerical models typical of environmental science. In this contribution we first derive the equations for the model error dynamics in the general case, and then for the particular situation of parametric error. We show how this deterministic description of the model error can be incorporated in sequential and variational data assimilation procedures. A numerical comparison with standard methods is given using low-order dynamical systems, prototypes of atmospheric circulation, and a realistic soil model. The deterministic approach proves to be very competitive with only minor additional computational c...

  20. Recent Advances Concerning Certain Class of Geophysical Flows

    CERN Document Server

    Li, Jinkai

    2016-01-01

    This paper is devoted to reviewing several recent developments concerning certain class of geophysical models, including the primitive equations (PEs) of atmospheric and oceanic dynamics and a tropical atmosphere model. The PEs for large-scale oceanic and atmospheric dynamics are derived from the Navier-Stokes equations coupled to the heat convection by adopting the Boussinesq and hydrostatic approximations, while the tropical atmosphere model considered here is a nonlinear interaction system between the barotropic mode and the first baroclinic mode of the tropical atmosphere with moisture. We are mainly concerned with the global well-posedness of strong solutions to these systems, with full or partial viscosity, as well as certain singular perturbation small parameter limits related to these systems, including the small aspect ratio limit from the Navier-Stokes equations to the PEs, and a small relaxation-parameter in the tropical atmosphere model. These limits provide a rigorous justification to the hydrost...

  1. Press conference bring excitement of geophysical research to the public

    Science.gov (United States)

    Leifert, Harvey

    “A Flare to Remember.” “Starbucks for Starfish.” “Earth's Rotation Slows for El Niño.” What do these catchy headlines have in common? They all resulted from presentations at AGU's Spring Meeting in Boston, Mass. Yes, geophysical science can be big news when presented in a way that is interesting to general audiences.Proof? Well, the “Flare to Remember” headline (in the Dallas Morning News) reported the discovery, via the SOHO spacecraft, that a solar flare had produced, deep inside the Sun, seismic disturbances of a magnitude never experienced on Earth. Researchers Valentina Zharkova of Glasgow University and Alexander Kosovichev of Stanford gave media representatives a preview of their session, supported by visual aids, in the AGU press briefing room.

  2. Flow networks: A characterization of geophysical fluid transport

    CERN Document Server

    Ser-Giacomi, Enrico; Lopez, Cristobal; Hernandez-Garcia, Emilio

    2014-01-01

    We represent transport between different regions of a fluid domain by flow networks, constructed from the discrete representation of the Perron-Frobenius or transfer operator associated to the fluid advection dynamics. The procedure is useful to analyze fluid dynamics in geophysical contexts, as illustrated by the construction of a flow network associated to the surface circulation in the Mediterranean sea. We use network-theory tools to analyze the flow network and gain insights into transport processes. In particular we quantitatively relate dispersion and mixing characteristics, classically quantified by Lyapunov exponents, to the degree of the network nodes. A family of network entropies is defined from the network adjacency matrix, and related to the statistics of stretching in the fluid, in particular to the Lyapunov exponent field. Finally we use a network community detection algorithm, Infomap, to partition the Mediterranean network into coherent regions, i.e. areas internally well mixed, but with lit...

  3. Modulational Instability in Basic Plasma and Geophysical Models

    CERN Document Server

    Quinn, Brenda; Connaughton, Colm; Gallagher, Steven; Hnat, Bogdan

    2013-01-01

    This is a review of the theory of the modulational instability in idealised fluid models of strongly magnetised plasmas and reduced models of geophysical fluid dynamics, particularly the role it plays in the formation of zonal flows. The discussion focusses on the Charney-Hasegawa-Mima and Hasegawa-Wakatani models. Particular attention is paid to the wave turbulence - zonal flow feedback loop whereby large scale zonal flows which are initially generated by modulational instability of small-scale drift/Rossby waves tend to subsequently suppress these small scale waves by their shearing action. This negative feedback can result in a dynamic equilibrium in which large scale zonal flows grow by drawing energy from small scale turbulence but suppress the small scale turbulence in the process until a balance is reached. In this regime, the level of small scale turbulence is greatly reduced compared to the level one would observe in the absence of the zonal flows.

  4. Inverse problems basics, theory and applications in geophysics

    CERN Document Server

    Richter, Mathias

    2016-01-01

    The overall goal of the book is to provide access to the regularized solution of inverse problems relevant in geophysics without requiring more mathematical knowledge than is taught in undergraduate math courses for scientists and engineers. From abstract analysis only the concept of functions as vectors is needed. Function spaces are introduced informally in the course of the text, when needed. Additionally, a more detailed, but still condensed introduction is given in Appendix B. A second goal is to elaborate the single steps to be taken when solving an inverse problem: discretization, regularization and practical solution of the regularized optimization problem. These steps are shown in detail for model problems from the fields of inverse gravimetry and seismic tomography. The intended audience is mathematicians, physicists and engineers having a good working knowledge of linear algebra and analysis at the upper undergraduate level.

  5. Geophysical imaging of shallow degassing in a Yellowstone hydrothermal system

    Science.gov (United States)

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

    2016-12-01

    The Yellowstone Plateau Volcanic Field, which hosts over 10,000 thermal features, is the world's largest active continental hydrothermal system, yet very little is known about the shallow "plumbing" system connecting hydrothermal reservoirs to surface features. Here we present the results of geophysical investigations of shallow hydrothermal degassing in Yellowstone. We measured electrical resistivity, compressional-wave velocity from refraction data, and shear wave velocity from surface-wave analysis to image shallow hydrothermal degassing to depths of 15-30 m. We find that resistivity helps identify fluid pathways and that Poisson's ratio shows good sensitivity to saturation variations, highlighting gas-saturated areas and the local water table. Porosity and saturation predicted from rock physics modeling provide critical insight to estimate the fluid phase separation depth and understand the structure of hydrothermal systems. Finally, our results show that Poisson's ratio can effectively discriminate gas- from water-saturated zones in hydrothermal systems.

  6. Efficient Multigrid Preconditioners for Anisotropic Problems in Geophysical Modelling

    CERN Document Server

    Dedner, Andreas; Scheichl, Robert

    2014-01-01

    Many problems in geophysical modelling require the efficient solution of highly anisotropic elliptic partial differential equations (PDEs) in "flat" domains. For example, in numerical weather- and climate-prediction an elliptic PDE for the pressure correction has to be solved at every time step in a thin spherical shell representing the global atmosphere. This elliptic solve can be one of the computationally most demanding components in semi-implicit semi-Lagrangian time stepping methods which are very popular as they allow for larger model time steps and better overall performance. With increasing model resolution, algorithmically efficient and scalable algorithms are essential to run the code under tight operational time constraints. We discuss the theory and practical application of bespoke geometric multigrid preconditioners for equations of this type. The algorithms deal with the strong anisotropy in the vertical direction by using the tensor-product approach originally analysed by B\\"{o}rm and Hiptmair ...

  7. Geology, geophysics and engineering: a case for synergism

    Energy Technology Data Exchange (ETDEWEB)

    Gretener, P.E.

    1984-06-01

    This article uses the example of artificial well fracturing to show how geologists, geophysicists and engineers can benefit from establishing an interdisciplinary dialogue. The term ''Ultimate Recovery'' is shown to be equally applicable to oil production and hard rock mining. While geology and geophysics schools gear their curricula toward the exploration for natural resources, engineers consider exploitation as their exclusive domain. It is proposed that geologists and geophysicists close ranks with the engineers and abolish the current state of separation which is being perpetuated by both sides. It is shown how geological considerations have helped to unravel the process of artificial well stimulation, while well stimulation in turn has provided valuable insights into the present stress conditions in various geological provinces.

  8. Parameterization of geophysical inversion model using particle clustering

    CERN Document Server

    Yang, Dikun

    2015-01-01

    This paper presents a new method of constructing physical models in a geophysical inverse problem, when there are only a few possible physical property values in the model and they are reasonably known but the geometry of the target is sought. The model consists of a fixed background and many small "particles" as building blocks that float around in the background to resemble the target by clustering. This approach contrasts the conventional geometric inversions requiring the target to be regularly shaped bodies, since here the geometry of the target can be arbitrary and does not need to be known beforehand. Because of the lack of resolution in the data, the particles may not necessarily cluster when recovering compact targets. A model norm, called distribution norm, is introduced to quantify the spread of particles and incorporated into the objective function to encourage further clustering of the particles. As proof of concept, 1D magnetotelluric inversion is used as example. My experiments reveal that the ...

  9. Surface Geophysical Measurements for Locating and Mapping Ice-Wedges

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Larsen, S.H.

    2012-01-01

    With the presently observed trend of permafrost warming and degradation, the development and availability of effective tools to locate and map ice-rich soils and massive ground ice is of increasing importance. This paper presents a geophysical study of an area with polygonal landforms in order...... to test the applicability of DC electrical resistivity tomography (ERT) and Ground Penetrating Radar (GPR) to identifying and mapping ice-wedge occurrences. The site is located in Central West Greenland, and the ice-wedges are found in a permafrozen peat soil with an active layer of about 30 cm. ERT...... and GPR measurements give a coherent interpretation of possible ice-wedge locations, and active layer probing show a tendency for larger thaw depth in the major trench systems consistent with a significant temperature (at 10 cm depth) increase in these trenches identified by thermal profiling. Three...

  10. Circular structures of Bajada del Diablo (Argentina): geophysical signatures

    Science.gov (United States)

    Prezzi, C. B.; Orgeira, M. J.; Martinez, O.; Acevedo, R. D.; Ponce, F.; Goldmann, G.; Magneres, I.; Rabassa, J.

    2016-05-01

    Bajada del Diablo is located in the Northern Patagonian Massif, Chubut, Argentina. The study area includes several circular structures found in Miocene olivine basalts of the Quiñelaf Eruptive Complex and in the Late Pliocene/Early Pleistocene Pampa Sastre conglomerates. An impact origin has been proposed for these circular structures. With the aim of further investigate the proposed impact origin, topographic, gravimetric, magnetic, resistivity, palaeomagnetic and electromagnetic surveys in two circular structures (`8' and `G') located in Pampa Sastre conglomerates and in basalts of the Quiñelaf Eruptive Complex were carried out. The new geophysical results support the hypothesis of an impact origin. However, the confirmation of such an origin through the findings of shock metamorphism evidences and/or the recovery of meteorites remains elusive.

  11. Particle-laden flow from geophysical to Kolmogorov scales

    CERN Document Server

    Clercx, Herman; Uijttewaal, Wim

    2007-01-01

    The dispersion of particles in a flow is of central importance in various geophysical and environmental problems. The spreading of aerosols and soot in the air, the growth and dispersion of plankton blooms in seas and oceans, or the transport of sediment in rivers, estuaries and coastal regions are striking examples. These problems are characterized by strong nonlinear coupling between several dynamical mechanisms. As a result, processes on widely different length and time scales are simultaneously of importance. The multiscale nature of this challenging field motivated the EUROMECH colloquium on particle-laden flow that was held at the University of Twente in 2006. This book contains a selection of the papers that were presented.

  12. New tool developed for visualizing and manipulating geophysical data

    Science.gov (United States)

    Zhou, Shaohua

    Free new software for geophysical data handling and visualization has been released. The software, called the extended Visu, is a public domain program for UNIX machines. It is designed for the visualization and interactive manipulation of two-dimensional gridded scientific data. This software was developed on top of the previously released free software, Visu-2.0, by Pierre-Louis Bossart of the Lawrence Livermore National Laboratory, who wrote the original program that performs all the data formatting, color allocation, and display work. The current version of the extended Visu is a Tk extension of the scripting language Tcl/Tk, one of the most powerful software developing languages for writing graphical user interface (GUI) programs.

  13. Human responses to the geophysical daily, annual and lunar cycles.

    Science.gov (United States)

    Foster, Russell G; Roenneberg, Till

    2008-09-09

    Collectively the daily, seasonal, lunar and tidal geophysical cycles regulate much of the temporal biology of life on Earth. The increasing isolation of human societies from these geophysical cycles, as a result of improved living conditions, high-quality nutrition and 24/7 working practices, have led many to believe that human biology functions independently of them. Yet recent studies have highlighted the dominant role that our circadian clock plays in the organisation of 24 hour patterns of behaviour and physiology. Preferred wake and sleep times are to a large extent driven by an endogenous temporal program that uses sunlight as an entraining cue. The alarm clock can drive human activity rhythms but has little direct effect on our endogenous 24 hour physiology. In many situations, our biology and our society appear to be in serious opposition, and the damaging consequences to our health under these circumstances are increasingly recognised. The seasons dominate the lives of non-equatorial species, and until recently, they also had a marked influence on much of human biology. Despite human isolation from seasonal changes in temperature, food and photoperiod in the industrialised nations, the seasons still appear to have a small, but significant, impact upon when individuals are born and many aspects of health. The seasonal changes that modulate our biology, and how these factors might interact with the social and metabolic status of the individual to drive seasonal effects, are still poorly understood. Lunar cycles had, and continue to have, an influence upon human culture, though despite a persistent belief that our mental health and other behaviours are modulated by the phase of the moon, there is no solid evidence that human biology is in any way regulated by the lunar cycle.

  14. Estimating Climate Resilience for Conservation across Geophysical Settings

    Science.gov (United States)

    ANDERSON, MARK G; CLARK, MELISSA; SHELDON, ARLENE OLIVERO

    2014-01-01

    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 SD 0.5 por encima del puntaje combinado promedio para cada escenario. Nuestra hipótesis fue que estos sitios con altas puntuaciones tuvieron la mayor capacidad de recuperación. Los comparamos con los sitios seleccionados por The Nature Conservancy por sus poblaciones de alta calidad de especies raras y sus ocurrencias de comunidades naturales. Los sitios con altos puntajes capturaron significativamente más de los sitios de biodiversidad de lo que se esperaba por casualidad (p funciones más tiempo bajo un clima cambiante, revela baluartes naturales para la conservación futura que también capturaría biodiversidad existente sustancial y corregiría el sesgo en tierras que actualmente están aseguradas. PMID:24673543

  15. Geophysical study of the Monroe-Red Hill geothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Mase, C.W.; Chapman, D.S.; Ward, S.H.

    1978-10-01

    A detailed geophysical study consisting of heat flow, dipole-dipole resistivity, ground magnetics and gravity was conducted in the vicinity of Monroe, Utah to assess the resource potential of an identified hydrothermal system. The detailed study covered a 40 km/sup 2/ area along the Sevier fault near the Monroe-Red Hill hot springs. Fourteen 100m dipole-dipole resistivity profiles across the system were used to construct a first separation apparent resistivity contour map. The map effectively outlines the trace of the Sevier fault and reveals an elongate zone of low resistivity (< 10 ..cap omega..-m) associated with the hydrothermal system. Similar features are evident on the total magnetic intensity anomaly map. Gravity modeling across the system indicates that the Sevier fault is comprised of three or more nearly vertical en echelon faults. On the basis of geological mapping and surface geophysical surveys a series of eleven shallow boreholes (40 to 90m was drilled on two profiles across the system. Surface geothermal gradients vary from 240/sup 0/C km/sup -1/ to over 1000/sup 0/C km/sup -1/ along the profiles. Heat flow values vary smoothly from 550 mW m/sup -2/ to over 3000 mW m/sup -2/, a significant enhancement over background Basin and Range heat flow of 80 mW m/sup -2/. Heat budget calculations based on conductive heat loss and enthalpy of the discharge waters indicae a net power loss of 7.8 MW.

  16. Integrated Geophysical Analysis at a Legacy Test Site

    Science.gov (United States)

    Yang, X.; Mellors, R. J.; Sweeney, J. J.; Sussman, A. J.

    2015-12-01

    We integrate magnetic, electromagnetic (EM), gravity, and seismic data to develop a unified and consistent model of the subsurface at the U20ak site on Pahute Mesa at the Nevada National Nuclear Security Site (NNSS). The 1985 test, conducted in tuff at a depth of approximately 600 m did not collapse to the surface or produce a crater. The purpose of the geophysical measurements is to characterize the subsurface above and around the presumed explosion cavity. The magnetic data are used to locate steel borehole casings and pipes and are correlated with surface observations. The EM data show variation in lithology at depth and clear signatures from borehole casings and surface cables. The gravity survey detects a clear gravity low in the area of the explosion. The seismic data indicates shallow low velocity zone and indications of a deeper low velocity zones. In this study, we conduct 2D inversion of EM data for better characterization of site geology and use a common 3D density model to jointly interpret both the seismic and gravity data along with constraints on lithology boundaries from the EM. The integration of disparate geophysical datasets allows improved understanding of the non-prompt physical signatures of an underground nuclear explosion (UNE). LLNL Release Number: LLNL-ABS-675677. The authors express their gratitude to the National Nuclear Security Administration, Defense Nuclear Nonproliferation Research and Development, and the Comprehensive Inspection Technologies and UNESE working group, a multi-institutional and interdisciplinary group of scientists and engineers. This work was performed by Lawrence Livermore National Laboratory and Los Alamos National Laboratory under award number DE-AC52-06NA25946.

  17. Temporal associations of life with solar and geophysical activity

    Directory of Open Access Journals (Sweden)

    T. K. Breus

    Full Text Available In biology, circadian rhythms with a period of one cycle in 20–28 h are known to be ubiquitous and partly endogenous. Rhythms with a frequency lower than one cycle per day are called 'infradian rhythms'. Among them are components with one cycle in about 3.5, 7, 14 and 28 days, the multiseptans, which, like the circadians, must be regarded as a general characteristic of life: they characterize unicells as well as much more differentiated organisms. We hypothesize that heliogeophysical factors other than the solar visible light, held responsible for the evolution of circadian periodicity, underlie the infradian rhythms of biosystems. The periodicities in the solar wind and variations in the interplanetary magnetic field (IMF which are associated with the solar rotation are very similar in length to the biological periodicities. We investigate the temporal relations of variations in solar activity and in biological systems to test associations between events in the IMF, in geomagnetic disturbance, in myocardial infarction and in physiology. By cross-spectral analysis, we also find relations at certain frequencies between changes in human physiology on the one hand, and (1 the vertical component of the induction vector of the IMF, Bz, and (2 a global index of geomagnetic disturbance, Kp, on the other hand. We wish to stimulate interest in these periodicities of both biological systems and geophysical endpoints among physicists and biologists alike, so that problems relevant to clinicians and other biologists, including evolutionists, are eventually solved by their cooperation with the geophysical community.

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

    Directory of Open Access Journals (Sweden)

    S. B. Joye

    2005-05-01

    Full Text Available Geophysical, temperature, and discrete depth-stratified geochemical data illustrate differences between an actively venting mud volcano and a relatively quiescent brine pool in the Gulf of Mexico along the continental slope. Geophysical data, including laser-line scan mosaics and sub-bottom profiles, document the dynamic nature of both environments. Temperature profiles, obtained by lowering a CTD into the brine fluid, show that the venting brine was at least 10°C warmer than the bottom water. At the brine pool, two thermoclines were observed, one directly below the brine-seawater interface and a second about one meter below the first. At the mud volcano, substantial temperature variability was observed, with the core brine temperature being either slightly (~2°C in 1997 or substantially (19°C in 1998 elevated above bottom water temperature. Geochemical samples were obtained using a device called the "brine trapper" and concentrations of dissolved gases, major ions and nutrients were determined using standard techniques. Both brines contained about four times as much salt as seawater and steep concentration gradients of dissolved ions and nutrients versus brine depth were apparent. Differences in the concentrations of calcium, magnesium and potassium between the two brine fluids suggests that the fluids are derived from different sources or that brine-sediment reactions are more important at the mud volcano than the brine pool. Substantial concentrations of methane and ammonium were observed in both brines, suggesting that fluids expelled from deep ocean brines are important sources of methane and dissolved inorganic nitrogen to the surrounding environment.

  19. High Resolution Geophysical Characterization of Fractures within a Granitic Pluton

    Science.gov (United States)

    Pérez-Estaún, A.; Carbonell, R.

    2007-12-01

    The FEBEX underground gallery was excavated in the Aar Granite (Switzerland), a heterogeneous granite containing from very leucocratic facies to granodiorites. The geology of the gallery shows the existence of various sets of fractures with different attributes: geometry, kinematics, fracture infilling, etc. The study of the structural data, new observations on the FEBEX gallery itself and borehole televiewer data acquired in the newly drilled boreholes, have allowed to identify four sets of fractures. The first group of fractures has a typical distribution and characteristics of en echelon tension fractures and were formed in late magmatic stages, according with the paragenesis of the minerals that filled the craks. The main strike is around 300 (280-300). These fractures are deformed and displaced by the other group of faults. The second group corresponds to the lamprophyre dikes, of mantelic origin, with an orientation oblique to the tunnel, and slightly oblique to the first group of fractures (strike, 310-330). They were formed during an extension event well evidenced by their irregular margins and flame structures into the granite. The margins of these dikes show several reactivations as strike slip faults. Geophysical data has been acquired to characterized the fracture network of the surrounding volume within the FEBEX gallery. The geophysic data include new borehole logging such as Natural Gamma and Borehole Ground Penetrating radar. The processing and integration of these different data sets indicates that the GPR record can provide images of a third set of fractures, which are probably fluid filled. This set of fractures a subparallel to the tunnel axis and appear to intersect older boreholes which are nearly perpendicular to the axis of the FEBEX gallery.

  20. Geophysical Investigations at Hidden Dam, Raymond, California Flow Simulations

    Science.gov (United States)

    Minsley, Burke J.; Ikard, Scott

    2010-01-01

    Numerical flow modeling and analysis of observation-well data at Hidden Dam are carried out to supplement recent geophysical field investigations at the site (Minsley and others, 2010). This work also is complementary to earlier seepage-related studies at Hidden Dam documented by Cedergren (1980a, b). Known seepage areas on the northwest right abutment area of the downstream side of the dam was documented by Cedergren (1980a, b). Subsequent to the 1980 seepage study, a drainage blanket with a sub-drain system was installed to mitigate downstream seepage. Flow net analysis provided by Cedergren (1980a, b) suggests that the primary seepage mechanism involves flow through the dam foundation due to normal reservoir pool elevations, which results in upflow that intersects the ground surface in several areas on the downstream side of the dam. In addition to the reservoir pool elevations and downstream surface topography, flow is also controlled by the existing foundation geology as well as the presence or absence of a horizontal drain in the downstream portion of the dam. The current modeling study is aimed at quantifying how variability in dam and foundation hydrologic properties influences seepage as a function of reservoir stage. Flow modeling is implemented using the COMSOL Multiphysics software package, which solves the partially saturated flow equations in a two-dimensional (2D) cross-section of Hidden Dam that also incorporates true downstream topography. Use of the COMSOL software package provides a more quantitative approach than the flow net analysis by Cedergren (1980a, b), and allows for rapid evaluation of the influence of various parameters such as reservoir level, dam structure and geometry, and hydrogeologic properties of the dam and foundation materials. Historical observation-well data are used to help validate the flow simulations by comparing observed and predicted water levels for a range of reservoir elevations. The flow models are guided by, and

  1. Field Geophysics Class at Volcán Tungurahua, Ecuador

    Science.gov (United States)

    Johnson, Jeffrey; Ruiz, Mario

    2009-11-01

    Ecuador's erupting Volcán Tungurahua was the recent site of a 3-week graduate-level geophysical course on volcanoes, hosted by Ecuador's Instituto Geofisico of the Escuela Politecnica Nacional (IG-EPN) and the Department of Earth Science at the New Mexico Institute of Mining and Technology (NMT). Sixteen students from 12 universities and four countries participated in the intensive course, which entailed broadband seismometer and infrasound sensor deployment followed by subsequent data processing, analysis, interpretation, and result synthesis. Hardware for the course was provided by the Incorporated Research Institutes for Seismology (IRIS) through the Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL) as well as the IG-EPN and NMT geophysics programs. Since the start of its most recent eruptive period (in 1999), Tungurahua has proved itself a reliable source of both seismicity and infrasound radiating from its typically open vent. As such, Tungurahua provides the ultimate outdoor teaching laboratory where students can deploy instruments for just a few days and then collect earthquake and explosion data. Tungurahua's activity in June 2009 did not disappoint class participants: Frequent earthquakes included long-period and volcano tectonic events, various types of tremor events, and explosion earthquakes manifested by booming “cannon-shot” blasts. Some of the explosion shock waves were recorded 10 kilometers from the vent with excess pressure amplitudes greater than 50 pascals in the infrasonic band. Had these intense sounds been audible, their sound pressure levels at 10 kilometers would have been in excess of about 130 decibels!

  2. Water-Energy-Food Nexus: Compelling Issues for Geophysical Research

    Science.gov (United States)

    Akhbari, M.; Grigg, N. S.; Waskom, R.

    2014-12-01

    The joint security of water, food, and energy systems is an urgent issue everywhere, and strong drivers of development and land use change, exacerbated by climate change, require new knowledge to achieve integrated solution using a nexus-based approach to assess inter-dependencies. Effective research-based decision support tools are essential to identify the major issues and interconnections to help in implementation of the nexus approach. The major needs are models and data to clearly and unambiguously present decision scenarios to local cooperative groups of farmers, electric energy generators and water officials for joint decisions. These can be developed by integrated models to link hydrology, land use, energy use, cropping simulation, and optimization with economic objectives and socio-physical constraints. The first step in modeling is to have a good conceptual model and then to get data. As the linking of models increases uncertainties, each one should be supplied with adequate data at suitable spatial and temporal resolutions. Most models are supplied with data by geophysical scientists, such as hydrologists, geologists, atmospheric scientists, soil scientists, and climatologists, among others. Outcomes of a recently-completed project to study the water-energy-food nexus will be explained to illuminate the model and data needs to inform future management actions across the nexus. The project included a workshop of experts from government, business, academia, and the non-profit sector who met to define and explain nexus interactions and needs. An example of the findings is that data inconsistencies among sectors create barriers to integrated planning. A nexus-based systems model is needed to outline sectoral inter-dependencies and identify data demands and gaps. Geophysical scientists can help to create this model and take leadership on designing data systems to facilitate sharing and enable integrated management.

  3. Inverse spatial principal component analysis for geophysical survey data interpolation

    Science.gov (United States)

    Li, Qingmou; Dehler, Sonya A.

    2015-04-01

    The starting point for data processing, visualization, and overlay with other data sources in geological applications often involves building a regular grid by interpolation of geophysical measurements. Typically, the sampling interval along survey lines is much higher than the spacing between survey lines because the geophysical recording system is able to operate with a high sampling rate, while the costs and slower speeds associated with operational platforms limit line spacing. However, currently available interpolating methods often smooth data observed with higher sampling rate along a survey line to accommodate the lower spacing across lines, and much of the higher resolution information is not captured in the interpolation process. In this approach, a method termed as the inverse spatial principal component analysis (isPCA) is developed to address this problem. In the isPCA method, a whole profile observation as well as its line position is handled as an entity and a survey collection of line entities is analyzed for interpolation. To test its performance, the developed isPCA method is used to process a simulated airborne magnetic survey from an existing magnetic grid offshore the Atlantic coast of Canada. The interpolation results using the isPCA method and other methods are compared with the original survey grid. It is demonstrated that the isPCA method outperforms the Inverse Distance Weighting (IDW), Kriging (Geostatistical), and MINimum Curvature (MINC) interpolation methods in retaining detailed anomaly structures and restoring original values. In a second test, a high resolution magnetic survey offshore Cape Breton, Nova Scotia, Canada, was processed and the results are compared with other geological information. This example demonstrates the effective performance of the isPCA method in basin structure identification.

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

    Directory of Open Access Journals (Sweden)

    S. B. Joye

    2005-01-01

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

  5. Investigation of a playa lake bed using geophysical electrical methods

    Science.gov (United States)

    Herrmenn, M.; Gurrola, H.; William, R.; Montalvo, R.; Horton, S.; Homberg, J.; Allen, T.; Bribiesca, E.; Lindsey, C.; Anderson, H.; Seshadri, S.; Manns, S.; Hassan, A.; Loren, C.

    2005-12-01

    The 2005 undergraduate applied geophysical class of Texas Tech University conducted a geophysical survey of a playa lake approximately 10 miles northwest of Lubbock Texas. The playa lake is primarily used as grazing land for two llamas and a hand full of sheep, and has been recently used as a dump for broken down sheds and barrels. Our goal was to model the subsurface of the transition from the playa to plains geology and investigate the possible contamination, of the soil and the data, by the metal dumped at the surface. We conducted our survey with and EM31 and homemade D.C. resistivity and SP equipment that allowed students to grasp the theories more clearly. SP readings were collected using clay pots constructed from terracotta pots and copper tubing purchased at the local hardware store and voltage measurements collected with handle held multi-meters. D.C. resistivity data were collected in a dipole-dipole array using 20 nine volt batteries connected in series with a large enough variable resistor and amp meter to regulate steady current flow. A multi meter was used to collect voltage readings. Wenner array data were collected using a home-made multi-filament cable connected switch box to allow a central user to regulate current and take voltage reading. A map of conductivity produced from a 10 m of EM31 reading show that conductivity anomalies mirror topography. The SP profiles show high values in the playa lake that drop off as we move from the clay rich lake bed to normal grassland. Analysis of both the Dipole-Dipole and Wenner array data support a model with 3 flat layers increasing in resistivity with depth. It appears that these remain flat passing beneath the playa and the playa is eroded into these layers.

  6. GEOFIM: A WebGIS application for integrated geophysical modeling in active volcanic regions

    Science.gov (United States)

    Currenti, Gilda; Napoli, Rosalba; Sicali, Antonino; Greco, Filippo; Negro, Ciro Del

    2014-09-01

    We present GEOFIM (GEOphysical Forward/Inverse Modeling), a WebGIS application for integrated interpretation of multiparametric geophysical observations. It has been developed to jointly interpret scalar and vector magnetic data, gravity data, as well as geodetic data, from GPS, tiltmeter, strainmeter and InSAR observations, recorded in active volcanic areas. GEOFIM gathers a library of analytical solutions, which provides an estimate of the geophysical signals due to perturbations in the thermal and stress state of the volcano. The integrated geophysical modeling can be performed by a simple trial and errors forward modeling or by an inversion procedure based on NSGA-II algorithm. The software capability was tested on the multiparametric data set recorded during the 2008-2009 Etna flank eruption onset. The results encourage to exploit this approach to develop a near-real-time warning system for a quantitative model-based assessment of geophysical observations in areas where different parameters are routinely monitored.

  7. The PROSPECT Physics Program

    CERN Document Server

    Ashenfelter, J; Band, H R; Barclay, G; Bass, C D; Berish, D; Bowden, N S; Bowes, A; Bryan, C D; Brodsky, J P; Cherwinka, J J; Chu, R; Classen, T; Commeford, K; Davee, D; Dean, D; Deichert, G; Diwan, M V; Dolinski, M J; Dolph, J; Gaison, J K; Galindo-Uribarri, A; Gilje, K; Glenn, A; Goddard, B W; Green, M; Han, K; Hans, S; Heeger, K M; Heffron, B; Jaffe, D E; Jones, D; Langford, T J; Littlejohn, B R; Caicedo, D A Martinez; McKeown, R D; Mendenhall, M P; Mueller, P; Mumm, H P; Napolitano, J; Neilson, R; Norcini, D; Pushin, D; Qian, X; Romero, E; Rosero, R; Seilhan, B S; Sharma, R; Sheets, S; Surukuchi, P T; Varner, R L; Viren, B; Wang, W; White, B; White, C; Wilhelmi, J; Williams, C; Wise, T; Yao, H; Yeh, M; Yen, Y -R; Zangakis, G; Zhang, C; Zhang, X

    2015-01-01

    The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and probe eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long distances. PROSPECT is conceived as a 2-phase experiment utilizing segmented $^6$Li-doped liquid scintillator detectors for both efficient detection of reactor antineutrinos through the inverse beta decay reaction and excellent background discrimination. PROSPECT Phase I consists of a movable 3-ton antineutrino detector at distances of 7 - 12 m from the reactor core. It will probe the best-fit point of the $\

  8. Prospective ergonomics: origin, goal, and prospects.

    Science.gov (United States)

    Robert, Jean-Marc; Brangier, Eric

    2012-01-01

    So far ergonomics has been concerned with two categories of activities: correction and design. We propose to add a third category: prospection, and by so doing, we introduce a new series of activities that opens up the future of ergonomics. Corrective ergonomics relates to the past and comes with a demand and a client. It is turned towards the correction of existing situations and aims to reduce or eliminate problems. Here, after delimiting and defining the problem, the challenge is to find the best solution. Ergonomics for design relates to the present and also comes with a demand and a client. It is turned towards the design of new artefacts that have already been identified by a client, and that will allow users to do some activity and attain their goals. Here, after defining the scope of the project and the functional requirements, the challenge is to do the best design. Finally, prospective ergonomics relates to the future and does not come with a demand and a client. It is turned towards the creation of future things that have not been identified yet. Here the challenge is to detect existing user needs or anticipate future ones, and imagine solutions. These three categories of activities overlap and are not exclusive of each other. In this paper we define prospective ergonomics and compare it with corrective ergonomics and ergonomics for design. We describe its origin, goal, and prospects, we analyze its impacts on education and practice, and we emphasize the need of new collaboration between ergonomics and other disciplines.

  9. Immersive, hands-on, team-based geophysical education at the University of Texas Marine Geology and Geophysics Field Course

    Science.gov (United States)

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

    2013-12-01

    The University of Texas Institute for Geophysics (UTIG), part of the Jackson School of Geosciences, annually offers a unique and intensive three-week marine geology and geophysics field course during the spring/summer semester intersession. Now entering its seventh year, the course transitions students from a classroom environment through real-world, hands-on field acquisition, on to team-oriented data interpretation, culminating in a professional presentation before academic and industry employer representatives. The course is available to graduate students and select upper-division undergraduates, preparing them for direct entry into the geoscience workforce or for further academic study. Geophysical techniques used include high-resolution multichannel seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, sediment coring, grab sampling, data processing, and laboratory analysis of sediments. Industry-standard equipment, methods, software packages, and visualization techniques are used throughout the course, putting students ahead of many of their peers in this respect. The course begins with a 3-day classroom introduction to the field area geology, geophysical methods, and computing resources used. The class then travels to the Gulf Coast for a week of hands-on field and lab work aboard two research vessels: UTIG's 22-foot, aluminum hulled Lake Itasca; and NOAA's 82-foot high-speed catamaran R/V Manta. The smaller vessel handles primarily shallow, inshore targets using multibeam bathymetry, sidescan sonar, and grab sampling. The larger vessel is used both inshore and offshore for multichannel seismic, CHIRP profiling, multibeam bathymetry, gravity coring, and vibracoring. Field areas to date have included Galveston and Port Aransas, Texas, and Grand Isle, Louisiana, with further work in Grand Isle scheduled for 2014. In the field, students work in teams of three, participating in survey design, instrument set-up, field deployment

  10. Numerical modeling of geophysical granular flows: 1. A comprehensive approach to granular rheologies and geophysical multiphase flows

    Science.gov (United States)

    Dartevelle, SéBastien

    2004-08-01

    Geophysical granular materials display a wide variety of behaviors and features. Typically, granular flows (1) are multiphase flows, (2) are very dissipative over many different scales, (3) display a wide range of grain concentrations, and (4), as a final result of these previous features, display complex nonlinear, nonuniform, and unsteady rheologies. Therefore the objectives of this manuscript are twofold: (1) setting up a hydrodynamic model which acknowledges the multiphase nature of granular flows and (2) defining a comprehensive rheological model which accounts for all the different forms of viscous dissipations within granular flows at any concentration. Hence three important regimes within granular flows must be acknowledged: kinetic (pure free flights of grain), kinetic-collisional, and frictional. The momentum and energy transfer will be different according to the granular regimes, i.e., strain rate dependent in the kinetic and kinetic-collisional cases and strain rate independent in the frictional case. A "universal" granular rheological model requires a comprehensive unified stress tensor able to adequately describe viscous stress within the flow for any of these regimes, and without imposing a priori what regime will dominate over the others. The kinetic-collisional viscous regime is defined from a modified Boltzmann's kinetic theory of dense gas. The frictional viscous regime is defined from the plastic potential and the critical state theories which account for compressibility of granular matter (e.g., dilatancy, consolidation, and critical state). In the companion paper [, 2004] we will introduce a multiphase computer code, (G)MFIX, which accounts for all the granular regimes and rheology and present typical simulations of diluted (e.g., plinian clouds) and concentrated geophysical granular flows (i.e., pyroclastic flows and surges).

  11. Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites: Closed Castner Range Fort Bliss, TX

    Science.gov (United States)

    2016-04-01

    classification . The project purpose is to locate and interrogate anomalies with the Time-domain Electromagnetic Multi-sensor Towed Array Detection System ...contained in Geophysical System Verification (GSV): A Physics -Based Alternative to Geophysical Prove Outs for Munitions Response (ESTCP 2009). The IVS...January 2007 (April 2007 revised). ESTCP. 2009. “Geophysical System Verification (GSV): A Physics -Based Alternative to Geophysical Prove-Outs for

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

    Science.gov (United States)

    2016-04-01

    ESTCP to test the effectiveness of advanced geophysical sensors and physics -based data analysis tools for anomaly classification . The project purpose is...the project data. 50 10.0 REFERENCES ESTCP. 2009. “Geophysical System Verification (GSV): A Physics -Based Alternative to Geophysical Prove-Outs for...Technical Report Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites - East Fork Valley

  13. Problems, Prospects And Challenges.

    African Journals Online (AJOL)

    Urban Road Transportation in Nigeria From 1960 To 2006: Problems, Prospects And Challenges. ... Ethiopian Journal of Environmental Studies and Management ... The paper suggested the construction of more motor-able roads within cities ...

  14. 30 CFR 251.12 - Submission, inspection, and selection of geophysical data and information collected under a...

    Science.gov (United States)

    2010-07-01

    ... geophysical data and information collected under a permit and processed by permittees or third parties. 251.12..., and selection of geophysical data and information collected under a permit and processed by permittees or third parties. (a) Availability of geophysical data and information collected under a permit....

  15. 30 CFR 280.51 - What types of geophysical data and information must I submit to MMS?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What types of geophysical data and information... CONTINENTAL SHELF Data Requirements Geophysical Data and Information § 280.51 What types of geophysical data... navigational data and final location maps; (b) All seismic data collected under a permit presented in a...

  16. Applied Geophysics in the world of tomorrow - Microfabrication arrives

    Science.gov (United States)

    Johnson, R. M.

    2012-12-01

    Instrument manufacturers have a unique perspective on the design and use of geophysical equipment. The field instrument must provide reliable and repeatable performance in every climate condition and environmental extreme. The gear must be easy to use and more importantly easy to understand for non-native English speakers. I have traveled the world installing, repairing, commissioning and demonstrating geophysical survey systems. Everywhere I have traveled there is one unassailable fact - our geophysicist compatriots in developed and developing countries are hungry for information and hungry for technology. They want more and better systems to help improve their understanding of the subsurface. And they want to serve their countries by helping to exploit natural resources. I hold up for your review the first highly successful portable magnetometer, the G-856. Designed in 1981 with over 5000 sold, it is still produced in record numbers today for use all over the world. How could it be that a rather simple device could be so long lived, and make such an impact in exploration programs for 32 years? The answer is in producing reliable and easy to use equipment that is affordable. One might compare it to the iPad or Android device of today. The innovative and no-frills interface has attracted users from all markets including mining, oil/gas, archaeology, environmental, UXO/military and forensics. Powerful ancillary software to process the data has always been included at no charge, offering geoscientists a solution rather than a black box. Many of our technologies are poised for dramatic breakthroughs in miniaturization and interconnectivity. I point specifically to the micro-fabrication of the cesium vapor magnetometer. Initiated 5 years ago in conjunction with NIST, Geometrics has embarked on a high stakes game of minimizing size, weight, power consumption and price while eliminating dead zones and maintaining or increasing sensitivity and sample speed. These new

  17. Lithosphere types in North China: Evidence from geology and geophysics

    Institute of Scientific and Technical Information of China (English)

    QIU; Ruizhao; DENG; Jinfu; ZHOU; Su; LI; Jinfa; XIAO; Qingh

    2005-01-01

    On the basis of the characteristics of geology and geophysics in North China, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method (based on the information from Precambrian rock assemblages, igneous activities, deep-seated enclaves, etc.) and the relationship between seismic velocity and rock compositions, the crust-mantle petrological and chemical structure models can be set up. Researching results indicate that the geology and geophysics of North China platform bears the similar characteristics in comparison with those of the global typical cratons. The Eerduosi(Ordos) block located in the west of the North China Platform is a remnant of cratonic lithosphere after the North China platform had undergone "activation" in Mesozoic and "reconstruction" in Cenozoic times. The continental crust consists mainly of TTG rock assemblage while the subcontinental lithosphere mantle mainly consists of strongly depleted harzburgite. The craton was finally formed in late Archaean and early Proterozoic, and has been kept in stability up to present; its crustal-mantle petrological structures of lithosphere can be set up as a reference for the study of North China craton and even Sino-Korean craton. In the Mesozoic period, the middle and east areas of North China platform were activated in the Yanshanian orogenic process, the continental crust was reformed by material and heat-transfer of convective mantle and the original crustal TTG component was reconstructed to be granitic crust, and the subcontinental lithosphere mantle was replaced by the Yanshanian harzburgite-lherzolite. The Yanshan-Taihang Mountains were the remnants of orogenic lithosphere after the rifting in eastern North China in Cenozoic. The present thickness of continental crust and lithosphere in the Yanshan-Taihang Mountains is not equal to their thickness during the Yanshanian orogenic movement because they had undergone the

  18. Investigation of subrosion processes using an integrated geophysical approach

    Science.gov (United States)

    Miensopust, Marion; Hupfer, Sarah; Kobe, Martin; Schneider-Löbens, Christiane; Wadas, Sonja

    2017-04-01

    Subrosion, i.e., leaching of readily soluble rocks, is usually of natural origin but can be enhanced by anthropogenic interferences. In recent years, public awareness of subrosion processes in terms of the in parts catastrophic implications and incidences increased. Especially the sinkholes in Schmalkalden, Tiefenort and Nordhausen (Germany) are three dramatic examples. They show that the knowledge of those processes and therefore, the predictability of such events is insufficient. The complexity of subrosion processes requires an integrated geophysical approach, which investigates the interlinking of structure, hydraulics, leaching, and mechanics. This contributes to a better understanding of the processes by reliable imaging and characterisation of subrosion structures. At LIAG an inter-sectional group is engaged in geophysical investigation of subrosion processes. The focus is application, enhancement and combination of various geophysical methods both at surface and in boreholes. This includes the monitoring of surface deformation and the application of time-lapse gravity as well as seismic, geoelectric and electromagnetic methods. Petrophysical investigations (with focus on Spectral Induced Polarisation - SIP) are conducted to characterise the processes on pore scale. Numerical studies are applied to advance the understanding of void forming processes and the mechanical consequences in the dynamic interaction. Since March 2014, quarterly campaigns are conducted to monitor changes in gravity acceleration at 15 stations in the urban area of Bad Frankenhausen. The standard deviations of the adjusted gravity differences are in the single-digit µGal range. The gravity acceleration changes in the range of 0 to 15 µGal over a timespan of three years and the accompanying levelling locally shows continuous subsidence in the mm/year-range. Sixteen SH-wave and four P-wave reflection seismic profiles together with three VSṔs were surveyed in the city of Bad

  19. An Integrated Geophysical Strategy to "Follow the Water" on Mars.

    Science.gov (United States)

    Clifford, S. M.; George, J. A.; Stoker, C. R.

    2001-12-01

    The abundance and distribution of subsurface water on Mars has important implications for understanding the geologic, hydrologic, and climatic evolution of the planet; the potential origin and continued survival of life; and the accessibility of a critical in situ resource for sustaining future human explorers. For this reason, a principal goal of the international Mars exploration program is to determine the 3-D distribution and state of subsurface H2O, at a resolution sufficient to permit reaching any desired volatile target by drilling. The highest priority targets include: groundwater (both shallow and deep), massive deposits of segregated ground ice (associated with the frozen discharge of the outlfow channels or the relic of a former ocean), and the polar layered deposits. Unfortunately, our ignorance about the heterogeneous nature and thermal evolution of the Martian crust effectively precludes geomorphic or theoretical attempts to quantitatively assess the current geographic and subsurface vertical distribution of ground ice and groundwater. As a result, any exploration activity (such as drilling) whose success is contingent on the presence of subsurface water, must be preceded by a comprehensive high-resolution geophysical survey capable of assessing whether local reservoirs of water and ice actually exist. Terrestrial experience has demonstrated that the accurate identification of such targets is likely to require the application of multiple geophysical techniques. Here we propose a two-phase approach to "following the water" on Mars - the first phase consisting of global reconnaissance missions dedicated to identifying and prioritizing potential volatile targets, followed by a second phase of high-resolution investigations of the most promising sites. Currently, the two missions that appear best suited for conducting a global survey are: (i). a 2nd-Generation Orbital Radar Sounder (optimized to sound both the shallow- and deep-subsurface). The potential

  20. Geophysical investigation of subrosion processes - an integrated approach

    Science.gov (United States)

    Miensopust, Marion; Hupfer, Sarah; Kobe, Martin; Schneider-Löbens, Christiane; Wadas, Sonja; Krawczyk, Charlotte

    2016-04-01

    Subrosion, i.e., leaching of readily soluble rocks mostly due to groundwater, is usually of natural origin but can be enhanced by anthropogenic interferences. In recent years, public awareness of subrosion processes in terms of the in parts catastrophic implications and incidences increased. Especially the sinkholes in Schmalkalden and Tiefenort (Germany) are - based on unforeseen collapse events and associated damage in 2010 - two dramatic examples. They illustrate that to date the knowledge of those processes and therefore the predictability of such events is insufficient. The complexity of the processes requires an integrated geophysical approach which investigates the interlinking of structure, hydraulics, solution processes, and mechanics. This finally contributes to a better understanding of the processes by reliable imaging and characterisation of subrosion structures. At LIAG an inter-sectional group is engaged in geophysical investigation of subrosion processes. The focus is application, enhancement and combination of various geophysical methods both at surface and in boreholes. This includes monitoring of (surface) deformation and variation of gravity as well as seismic, geoelectric and electromagnetic methods. Petrophysical investigations (with focus on spectral induced polarisation - SIP) are conducted to characterise the processes on pore scale. Numerical studies are applied to advance the understanding of void forming processes and the mechanical consequences in the dynamic interaction. Since March 2014, quarterly campaigns are conducted to monitor time-lapse gravity changes at 12 stations in the urban area of Bad Frankenhausen. The standard deviations of the gravity differences between the survey points are low and the accompanying levelling locally shows continuous subsidence in the mm/year-range. Eight shear-wave reflection seismic profiles were surveyed in Bad Frankenhausen using a landstreamer and an electro-dynamic vibrator. This method is

  1. Near surface geophysical techniques on subsoil contamination: laboratory experiments

    Science.gov (United States)

    Capozzoli, Luigi; Giampaolo, Valeria; Rizzo, Enzo

    2016-04-01

    Hydrocarbons contamination of soil and groundwater has become a serious environmental problem, because of the increasing number of accidental spills caused by human activities. The starting point of any studies is the reconstruction of the conceptual site model. To make valid predictions about the flow pathways following by hydrocarbons compound is necessary to make a correct reconstruction of their characteristics and the environment in which they move. Near-surface geophysical methods, based on the study of electrical and electromagnetic properties, are proved to be very useful in mapping spatial distribution of the organic contaminants in the subsurface. It is well known, in fact, that electrical properties of the porous media are significantly influenced by hydrocarbons because, when contaminants enter the rock matrix, surface reaction occur between the contaminant and the soil grain surface. The main aim of this work is to investigate the capability of near-surface geophysical methods in mapping and monitoring spatial distribution of contaminants in a controlled setting. A laboratory experiment has been performed at the Hydrogeosite Laboratory of CNR-IMAA (Marsico Nuovo, PZ) where a box-sand has been contaminated by diesel. The used contaminant is a LNAPL, added to the sand through a drilled pipe. Contaminant behaviour and its migration paths have been monitored for one year by Electrical Resistivity measurements. In details, a Cross Borehole Electrical Resistivity Tomography techniques were used to characterize the contamination dynamics after a controlled hydrocarbon spillage occurring in the vadose zone. The approach with cross-borehole resistivity imaging provide a great advantage compared to more conventional surface electrical resistivity tomography, due to the high resolution at high depth (obviously depending on the depth of the well instrumented for the acquisition). This method has been shown to provide good information on the distribution of

  2. Genetic algorithms and their use in Geophysical Problems

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-04-01

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

  3. Distinct Element modeling of geophysical signatures during sinkhole collapse

    Science.gov (United States)

    Al-Halbouni, Djamil; Holohan, Eoghan P.; Taheri, Abbas; Dahm, Torsten

    2017-04-01

    A sinkhole forms due to the collapse of rocks or soil near the Earth's surface into an underground cavity. Such cavities represent large secondary pore spaces derived by dissolution and subrosion in the underground. By changing the stress field in the surrounding material, the growth of cavities can lead to a positive feedback, in which expansion and mechanical instability in the surrounding material increases or generates new secondary pore space (e.g. by fracturing), which in turn increases the cavity size, etc. A sinkhole forms due to the eventual subsidence or collapse of the overburden that becomes destabilized and fails all the way to the Earth's surface. Both natural processes like (sub)surface water movement and earthquakes, and human activities, such as mining, construction and groundwater extraction, intensify such feedbacks. The development of models for the mechanical interaction of a growing cavity and fracturing of its surrounding material, thus capturing related precursory geophysical signatures, has been limited, however. Here we report on the advances of a general, simplified approach to simulating cavity growth and sinkhole formation by using 2D Distinct Element Modeling (DEM) PFC5.0 software and thereby constraining pre-, syn- and post-collapse geophysical and geodetic signatures. This physically realistic approach allows for spontaneous cavity development and dislocation of rock mass to be simulated by bonded particle formulation of DEM. First, we present calibration and validation of our model. Surface subsidence above an instantaneously excavated circular cavity is tracked and compared with an incrementally increasing dissolution zone both for purely elastic and non-elastic material.This validation is important for the optimal choice of model dimensions and particles size with respect to simulation time. Second, a cavity growth approach is presented and compared to a well-documented case study, the deliberately intensified sinkhole collapse at

  4. Geophysical evaluation of the Success Dam foundation, Porterville, California

    Science.gov (United States)

    Hunter, L.E.; Powers, M.H.; Haines, S.; Asch, T.; Burton, B.L.; Serafini, D.C.

    2006-01-01

    Success Dam is a zonedearth fill embankment located near Porterville, CA. Studies of Success Dam by the recent Dam Safety Assurance Program (DSAP) have demonstrated the potential for seismic instability and large deformation of the dam due to relatively low levels of earthquake shaking. The U.S. Army Corps of Engineers conducted several phases of investigations to determine the properties of the dam and its underlying foundation. Detailed engineering studies have been applied using a large number of analytical techniques to estimate the response of the dam and foundation system when subjected to earthquake loading. Although a large amount of data have been acquired, most are 'point' data from borings and results have to be extrapolated between the borings. Geophysical techniques were applied to image the subsurface to provide a better understanding of the spatial distribution of key units that potentially impact the stability. Geophysical investigations employing seismic refraction tomography, direct current (DC) resistivity, audio magnetotellurics (AMT) and self-potential (SP) were conducted across the location of the foundation of a new dam proposed to replace the existing one. Depth to bedrock and the occurrence of beds potentially susceptible to liquefaction were the focus of the investigations. Seismic refraction tomography offers a deep investigation of the foundation region and looks at compressional and shear properties of the material. Whereas resistivity surveys determines conductivity relationships in the shallow subsurface and can produce a relatively high-resolution image of geological units with different electrical properties. AMT was applied because it has the potential to look considerably deeper than the other methods, is useful for confirming depth to bedrock, and can be useful in identifying deep seated faults. SP is a passive electrical method that measures the electrical streaming potential in the subsurface that responds to the movement of

  5. Geophysical Characterization of the Salna Sinking Zone, Garhwal Himalaya, India

    Science.gov (United States)

    Sastry, Rambhatla G.; Mondal, Suman K.

    2013-01-01

    Infrastructure and communication facilities are repeatedly affected by ground deformation in Gharwal Himalaya, India; for effective remediation measures, a thorough understanding of the real reasons for these movements is needed. In this regard, we undertook an integrated geophysical and geotechnical study of the Salna sinking zone close to the Main Central Thrust in Garhwal Himalaya. Our geophysical data include eight combined electrical resistivity tomography (ERT) and induced polarization imaging (IPI) profiles spanning 144-600 m, with 3-10 m electrode separation in the Wenner-Schlumberger configuration, and five micro-gravity profiles with 10-30 m station spacing covering the study region. The ERT sections clearly outline the heterogeneity in the subsurface lithology. Further, the ERT, IPI, and shaliness (shaleyness) sections infer the absence of clayey horizons and slip surfaces at depth. However, the Bouguer gravity analysis has revealed the existence of several faults in the subsurface, much beyond the reach of the majority of ERT sections. These inferred vertical to subvertical faults run parallel to the existing major lineaments and tectonic elements of the study region. The crisscross network of inferred faults has divided the entire study region into several blocks in the subsurface. Our studies stress that the sinking of the Salna village area is presently taking place along these inferred vertical to subvertical faults. The Chamoli earthquake in March 1999 probably triggered seismically induced ground movements in this region. The absence of few gravity-inferred faults in shallow ERT sections may hint at blind faults, which could serve as future source(s) for geohazards in the study region. Soil samples at two sites of study region were studied in a geotechnical laboratory. These, along with stability studies along four slope sections, have indicated the critical state of the study region. Thus, our integrated studies emphasize the crucial role of

  6. Integrated Geophysycal Prospecting in Late Antiquity and Early Medieval Sites in Italy

    Science.gov (United States)

    Giannotta, Maria Teresa; Leucci, Giovanni; De Giorgi, Lara; Matera, Loredana; Persico, Raffaele; Muci, Giuseppe

    2016-04-01

    In this contribution, the results of some integrated geophysical prospecting (magnetometric and GPR) are exposed. This work has been performed in collaboration between archaeologists and geophysicists within the research project "History and Global Archaeology of the Rural Landascapes in Italy, between Late Antiquity and Medieval period. Integrated systems of sources, methodologies, and technologies for a sustainable development", financed by the Italian Ministry for Instruction, University and Research MIUR. In particular, the archaeological sites of Badia and San Giovanni in Malcantone, both in the Apulia Region (eastern-southern Italy) have been prospect. The sites have been identified on the basis of available documents, archaeological surveys and testimonies. In particular, we know that in Badia [1] it was probable the presence of an ancient roman villa of the late ancient period (strongly damaged by the subsequent ploughing activities). Whereas in San Giovanni there is still, today, a small chapel (deconsecrated) that was likely to be part of a previous larger church (probably a basilica of the early Christian period) restricted in the subsequent centuries (probably in more phases). The Saracen raids of the XVI centuries made the site ruined and abandoned. In both sites integrated prospecting have been performed [2-6] with a the integration of archaeological, magnetometer and a GPR data have provided some interesting results, allowing to overcome the difficulties relative to an extensive GPR prospecting, that could not be performed because of the intrinsic superficial roughness and/or the intensive ploughing activities. The prospecting activities, in particular, have added elements that seem to confirm the main archaeological hypothesis that motivate their performing, as it will be show at the conference. References [1] M. T, Giannotta, G. Leucci, R. Persico, M. Leo Imperiale, The archaeological site of Badia in terra d'Otranto: contribution of the

  7. On structure-based priors in Bayesian geophysical inversion

    Science.gov (United States)

    de Pasquale, G.; Linde, N.

    2017-03-01

    Bayesian methods are extensively used to analyse geophysical data sets. A critical and somewhat overlooked component of high-dimensional Bayesian inversion is the definition of the prior probability density function that describes the joint probability of model parameters before considering available data sets. If insufficient prior information is available about model parameter correlations, then it is tempting to assume that model parameters are uncorrelated. When working with a spatially gridded model representation, this overparametrization leads to posterior realizations with far too much variability to be deemed realistic from a geological perspective. In this study, we introduce a new approach for structure-based prior sampling with Markov chain Monte Carlo that is suitable when only limited prior information is available. We evaluate our method using model structure measures related to standard roughness and damping metrics for l1- and l2-norms. We show that our structure-based prior approach is able to adequately sample the chosen prior distribution of model structure. The usefulness and applicability of the methodology is demonstrated on synthetic and field-based crosshole ground penetrating radar data. We find that our method provides posterior model realizations and statistics that are significantly more satisfactory than those based on underlying assumptions of uncorrelated model parameters or on explicit penalties on model structure within an empirical Bayes framework.

  8. Integrated Geophysical Techniques for Exploring Deep Volcanic Rock Reservoir

    Institute of Scientific and Technical Information of China (English)

    LiuXuejun; UDechun; ZhangChangjiang; RanXuefeng

    2003-01-01

    The Carboniferous and Pre-Carboniferous formations in Ludong, Zhungar basin, contain favorable oil/gas reservoirs. The Carboniferous formations, however, are complex in structure and exhibit lateral variations in lithology. Seismic reflections from Pre-Triassic formations are poor and the volcanic reservoirs are very difficult to identify. The analysis of physical properties concluded that the major targets in this region, i.e., the top of the Jurassic and Carboniferous formations, provide distinct density interfaces. The basic, intermediate and acid volcanic rocks were also different in density,resulting in distinguishable gravity anomalies. The differences in magnetism in this region existed not only between the volcanic rocks and clastic sedimentary rocks but also among volcanic rocks with different compositions. All formations and volcanic rocks of different lithologies presented high and low resistance interbeds, which are characterized by regional trends.The modeling study demonstrated that non-seismic integrated geophysical techniques should be feasible in this region, especiaUy the high-precision gravity/magnetic methods combined with long offset transient electromagnetic sounding.

  9. Modern Radar Techniques for Geophysical Applications: Two Examples

    Science.gov (United States)

    Arokiasamy, B. J.; Bianchi, C.; Sciacca, U.; Tutone, G.; Zirizzotti, A.; Zuccheretti, E.

    2005-01-01

    The last decade of the evolution of radar was heavily influenced by the rapid increase in the information processing capabilities. Advances in solid state radio HF devices, digital technology, computing architectures and software offered the designers to develop very efficient radars. In designing modern radars the emphasis goes towards the simplification of the system hardware, reduction of overall power, which is compensated by coding and real time signal processing techniques. Radars are commonly employed in geophysical radio soundings like probing the ionosphere; stratosphere-mesosphere measurement, weather forecast, GPR and radio-glaciology etc. In the laboratorio di Geofisica Ambientale of the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy, we developed two pulse compression radars. The first is a HF radar called AIS-INGV; Advanced Ionospheric Sounder designed both for the purpose of research and for routine service of the HF radio wave propagation forecast. The second is a VHF radar called GLACIORADAR, which will be substituting the high power envelope radar used by the Italian Glaciological group. This will be employed in studying the sub glacial structures of Antarctica, giving information about layering, the bed rock and sub glacial lakes if present. These are low power radars, which heavily rely on advanced hardware and powerful real time signal processing. Additional information is included in the original extended abstract.

  10. Evaluating petrophysical relationships in fractured rock using geophysical measurements

    Science.gov (United States)

    Robinson, J.; Slater, L. D.; Keating, K.; Parker, B. L.; Rose, C.; Meyer, J. R.; Johnson, C. D.; Robinson, T.; Pehme, P.; Chapman, S.; Day-Lewis, F. D.

    2015-12-01

    Quantification of the pore geometric properties controlling mass transfer rates in fractured rock aquifers is a challenging characterization problem, especially given the scales of heterogeneity. The efficiency of in-situ remediation efforts that target hydraulically connected and dead-end fracture zones is limited, in part, due to the diffusion of aqueous phase contaminants into and out of the less-mobile pore spaces in the matrix surrounding fractures. Two geophysical technologies, complex resistivity (CR) and nuclear magnetic resonance (NMR) are sensitive to pore geometry and may provide key information on transport parameters where diffusion can be a limiting factor in and around boreholes. We present laboratory CR and NMR data from cores collected from field sites with variable lithologies and examine the sensitivity of these measurements to less-mobile versus mobile porosity. Supporting data include surface area measurements using the Brunauer-Emmett-Teller (BET) method, pore size distributions from mercury porosimetry, gravimetric measurements of matrix total porosity and gas permeability. We examine the predictive capability of CR and NMR to determine these pore scale properties as a function of geological setting. The petrophysical relationships illustrate the potential for use of new borehole logging tools to determine the spatial variability of physical properties controlling mass transfer close to fractures. The correlations of measurements to rock-type specific relations indicate that minimal core measurements might be needed to calibrate the results to a specific site.

  11. Performance analysis of wireless sensor networks in geophysical sensing applications

    Science.gov (United States)

    Uligere Narasimhamurthy, Adithya

    Performance is an important criteria to consider before switching from a wired network to a wireless sensing network. Performance is especially important in geophysical sensing where the quality of the sensing system is measured by the precision of the acquired signal. Can a wireless sensing network maintain the same reliability and quality metrics that a wired system provides? Our work focuses on evaluating the wireless GeoMote sensor motes that were developed by previous computer science graduate students at Mines. Specifically, we conducted a set of experiments, namely WalkAway and Linear Array experiments, to characterize the performance of the wireless motes. The motes were also equipped with the Sticking Heartbeat Aperture Resynchronization Protocol (SHARP), a time synchronization protocol developed by a previous computer science graduate student at Mines. This protocol should automatically synchronize the mote's internal clocks and reduce time synchronization errors. We also collected passive data to evaluate the response of GeoMotes to various frequency components associated with the seismic waves. With the data collected from these experiments, we evaluated the performance of the SHARP protocol and compared the performance of our GeoMote wireless system against the industry standard wired seismograph system (Geometric-Geode). Using arrival time analysis and seismic velocity calculations, we set out to answer the following question. Can our wireless sensing system (GeoMotes) perform similarly to a traditional wired system in a realistic scenario?

  12. Preliminary Definition of Geophysical Regions in Western Eurasia

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, J.; Walter, W.R.; Flanagan, M.P,; O' Boyle, J.; Pasyanos, M.E.

    2000-04-03

    The authors present a regionalized crustal model of Western Eurasia, WEA. The model is constructed using results from published studies and maps of geological and geophysical parameters in this region, and was developed in conjunction with the updated regionalization of Middle East and North Africa by Walter et al.[2000]. As this is the first realization of the Eurasian modeling effort, they have limited themselves to only twelve broad regions. Particular attention has been given to identifying the boundaries for each region. The main use of this model will be to assist in monitoring the Comprehensive Nuclear Test Ban Treaty (CTBT). Specifically, this model will help them to calibrate and predict the travel time and amplitudes of various regional seismic phases and to locate events accurately. The model based approach allows them to readily calibrate both the seismic and the aseismic parts of western Eurasia. Each region is specified by an one-dimensional model of compressional and shear velocities, densities and layer thicknesses. Further improvements to this model will involve, but not be limited to, increasing the spatial coverage toward the east and west of Eurasia, identify sub-regions based on their distinct physical properties and the use of new and improved body wave and surface wave datasets. In the future, they expect to use this model and its successors to be the baseline model for calibration techniques, e.g., kriging, to improve their capability to detect, locate and discriminate different seismic events in Eurasia.

  13. Using geophysical techniques to control in situ thermal remediation

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, S.; Daily, W.; Ramirez, A.; Wilt, M. [Lawrence Livermore National Lab., CA (United States); Goldman, R.; Kayes, D.; Kenneally, K.; Udell, K. [California Univ., Berkeley, CA (United States); Hunter, R. [Infraseismic, Inc., Bakersfield, CA (United States)

    1994-01-22

    Monitoring the thermal and hydrologic processes that occur during thermal environmental remediation programs in near real-time provides essential information for controlling the process. Geophysical techniques played a crucial role in process control as well as for characterization during the recent Dynamic Underground Stripping Project demonstration in which several thousand gallons of gasoline were removed from heterogeneous soils both above and below the water table. Dynamic Underground Stripping combines steam injection and electrical heating for thermal enhancement with ground water pumping and vacuum extraction for contaminant removal. These processes produce rapid changes in the subsurface properties including changes in temperature fluid saturation, pressure and chemistry. Subsurface imaging methods are used to map the heated zones and control the thermal process. Temperature measurements made in wells throughout the field reveal details of the complex heating phenomena. Electrical resistance tomography (ERT) provides near real-time detailed images of the heated zones between boreholes both during electrical heating and steam injection. Borehole induction logs show close correlation with lithostratigraphy and, by identifying the more permeable gravel zones, can be used to predict steam movement. They are also useful in understanding the physical changes in the field and in interpreting the ERT images. Tiltmeters provide additional information regarding the shape of the steamed zones in plan view. They were used to track the growth of the steam front from individual injectors.

  14. Geophysical investigation of seepage beneath an earthen dam.

    Science.gov (United States)

    Ikard, S J; Rittgers, J; Revil, A; Mooney, M A

    2015-01-01

    A hydrogeophysical survey is performed at small earthen dam that overlies a confined aquifer. The structure of the dam has not shown evidence of anomalous seepage internally or through the foundation prior to the survey. However, the surface topography is mounded in a localized zone 150 m downstream, and groundwater discharges from this zone periodically when the reservoir storage is maximum. We use self-potential and electrical resistivity tomography surveys with seismic refraction tomography to (1) determine what underlying hydrogeologic factors, if any, have contributed to the successful long-term operation of the dam without apparent indicators of anomalous seepage through its core and foundation; and (2) investigate the hydraulic connection between the reservoir and the seepage zone to determine whether there exists a potential for this success to be undermined. Geophysical data are informed by hydraulic and geotechnical borehole data. Seismic refraction tomography is performed to determine the geometry of the phreatic surface. The hydro-stratigraphy is mapped with the resistivity data and groundwater flow patterns are determined with self-potential data. A self-potential model is constructed to represent a perpendicular profile extending out from the maximum cross-section of the dam, and self-potential data are inverted to recover the groundwater velocity field. The groundwater flow pattern through the aquifer is controlled by the bedrock topography and a preferential flow pathway exists beneath the dam. It corresponds to a sandy-gravel layer connecting the reservoir to the downstream seepage zone.

  15. Jose de Acosta (1539”1600): A pioneer of geophysics

    Science.gov (United States)

    Udías, Agustín

    One of the first books written about the American continent was by Father José de Acosta. Entitled Historia Natural y Moral de las Indias (i.e., Natural and Moral History of the Indias), it was published in Seville, Spain, in 1590 (Figure 1). The rapid printing of four editions in Spain in less than 20 yr and the translation of the book into French, Italian, German, Dutch, and Latin less than 15 yr after the first Spanish edition are signs of the rapid popularity that was achieved by this book in Europe.José de Acosta was born in 1539 in Medina del Campo, Spain. He joined the Jesuit Order in 1553 and travelled to America in 1572. He remained there for 15 yr, travelling frequently and visiting the territories that today belong to Peru, Bolivia, Chile, and Mexico. During his journeys, he took note of his observations of natural phenomena, many of them related to the geophysical sciences, such as the aspect of the skies, distribution of temperature, rain, and winds, volcanic activity, earthquakes, and a variety of new minerals, plants, and animals, as well as on the social behavior of the inhabitants of those lands.

  16. Delimitation of the Paranapanema Proterozoic block: A geophysical contribution

    Institute of Scientific and Technical Information of China (English)

    Mantovani,M.S.M; Quintas,M.C.L.; Shukowsky,W; BritoNeves,B.B.

    2005-01-01

    This study focuses on the basement structure of the Paraná Basin in South America, based on geological and geophysical data. It is a large intracratonic basin formed from the Late Ordovician until the Cretaceous,when a sequence of continentalflood basalts eruptions covered the entire basin, preceding the break-up of Western Gondwana. Isostatic modeling was applied to large gravity surveys comprising more than 12,000 gravity stations. The residual Bouguer anomaly pattern,representing the crustal contribution of the crystalline basement, as well as the sedimentary and volcanic layers of the basin, reveals similarities between the basement gravity signature and the exposed rock. The stress patterns of the Late Ordovician and Cretaceous tectonic events present a geographically coincident maximum,and the correlation between gravity highs and the main attenuation (beta factor) suggests the presence of some preexistent suture zones. The resultant mosaic of gravity blocks and the location of major faults give support to the presence of an important Proterozoic cratonic feature, here referred to as Paranapanema block.

  17. A micromachined angular-acceleration sensor for geophysical applications

    Science.gov (United States)

    Liu, Huafeng; Pike, W. T.

    2016-10-01

    This paper presents an angular-acceleration sensor that works as either an angular accelerometer or a gravity gradiometer and is based on the micro electromechanical system (MEMS) technology. The changes in the angle of the sensor mass are sensed by a rotational capacitive array transducer that is formed by electrodes on both the stator and rotor dies of the flip-chip-bonded MEMS chip (21 mm × 12.5 mm × 1 mm). The prototype was characterized, demonstrating a fundamental frequency of 27 Hz, a quality factor of 230 in air, and a sensitivity of 6 mV/(rad/s2). The demonstrated noise floor was less than 0.003 rad/s2/ √{ Hz } within a bandwidth of 0.1 Hz to 10 Hz, which is comparable with the conventional angular accelerometer and is better than the other reported MEMS sensors in low-frequency ranges. The features of small size and low cost suggest that this MEMS angular-acceleration sensor could be mounted on a drone, a satellite or even a Mars rover, and it is promising to be used for monitoring angular accelerations, aiding seismic recording, mapping gravity anomalies, and other geophysical applications for large-scale terrestrial and space deployments.

  18. Geophysical constraints on mirror matter within the Earth

    CERN Document Server

    Ignatiev, A Yu

    2000-01-01

    We have performed a detailed investigation of geophysical constraints on the possible admixture of mirror matter inside the Earth. On the basis of the Preliminary Reference Earth Model (PREM) -- the `Standard Model' of the Earth's interior -- we have developed a method which allows one to compute changes in various quantities characterising the Earth (mass, moment of inertia, normal mode frequencies etc.)due to the presence of mirror matter. As a result we have been able to obtain for the first time the direct upper bounds on the possible concentration of the mirror matter in the Earth. In terms of the ratio of the mirror mass to the Earth mass a conservative upper bound is $3.8\\times 10^{-3}$. We then analysed possible mechanisms (such as lunar and solar tidal forces, meteorite impacts and earthquakes) of exciting mirror matter oscillations around the Earth centre. Such oscillations could manifest themselves through global variations of the gravitational acceleration at the Earth's surface. We conclude that ...

  19. Does Geophysics Need "A new kind of Science"?

    Science.gov (United States)

    Turcotte, D. L.; Rundle, J. B.

    2002-12-01

    Stephen Wolfram's book "A New Kind of Science" has received a great deal of attention in the last six months, both positive and negative. The theme of the book is that "cellular automata", which arise from spatial and temporal coarse-graining of equations of motion, provide the foundations for a new nonlinear science of "complexity". The old science is the science of partial differential equations. Some of the major contributions of this old science have been in geophysics, i.e. gravity, magnetics, seismic waves, heat flow. The basis of the new science is the use of massive computing and numerical simulations. The new science is motivated by the observations that many physical systems display a vast multiplicity of space and time scales, and have hidden dynamics that in many cases are impossible to directly observe. An example would be molecular dynamics. Statistical physics derives continuum equations from the discrete interactions between atoms and molecules, in the modern world the continuum equations are then discretized using finite differences, finite elements, etc. in order to obtain numerical solutions. Examples of widely used cellular automata models include diffusion limited aggregation and site percolation. Also the class of models that are said to exhibit self-organized criticality, the sand-pile model, the slider-block model, the forest-fire model. Applications of these models include drainage networks, seismicity, distributions of minerals,and the evolution of landforms and coastlines. Simple cellular automata models generate deterministic chaos, i.e. the logistic map.

  20. Geophysical Hazards and Preventive Disaster Management of Extreme Natural Events

    Science.gov (United States)

    Ismail-Zadeh, A.; Takeuchi, K.

    2007-12-01

    Geophysical hazard is potentially damaging natural event and/or phenomenon, which may cause the loss of life or injury, property damage, social and economic disruption, or environmental degradation. Extreme natural hazards are a key manifestation of the complex hierarchical nonlinear Earth system. An understanding, accurate modeling and forecasting of the extreme hazards are most important scientific challenges. Several recent extreme natural events (e.g., 2004 Great Indian Ocean Earthquake and Tsunami and the 2005 violent Katrina hurricane) demonstrated strong coupling between solid Earth and ocean, and ocean and atmosphere. These events resulted in great humanitarian tragedies because of a weak preventive disaster management. The less often natural events occur (and the extreme events are rare by definition), the more often the disaster managers postpone the preparedness to the events. The tendency to reduce the funding for preventive disaster management of natural catastrophes is seldom follows the rules of responsible stewardship for future generations neither in developing countries nor in highly developed economies where it must be considered next to malfeasance. Protecting human life and property against earthquake disasters requires an uninterrupted chain of tasks: from (i) understanding of physics of the events, analysis and monitoring, through (ii) interpretation, modeling, hazard assessment, and prediction, to (iii) public awareness, preparedness, and preventive disaster management.