Publications - GPR 2016-1 | Alaska Division of Geological & Geophysical
Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey electromagnetic and magnetic airborne geophysical survey data compilation Authors: Burns, L.E., Fugro Airborne geophysical survey data compilation: Alaska Division of Geological & Geophysical Surveys Geophysical
Publications - GPR 2015-4 | Alaska Division of Geological & Geophysical
Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey airborne geophysical survey data compilation Authors: Burns, L.E., Geoterrex-Dighem, Stevens Exploration airborne geophysical survey data compilation: Alaska Division of Geological & Geophysical Surveys
Publications - GPR 2015-3 | Alaska Division of Geological & Geophysical
Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey electromagnetic and magnetic airborne geophysical survey data compilation Authors: Burns, L.E., Fugro Airborne magnetic airborne geophysical survey data compilation: Alaska Division of Geological & Geophysical
The Environmental Geophysics website features geophysical methods, terms and references; forward and inverse geophysical models for download; and a decision support tool to guide geophysical method selection for a variety of environmental applications.
Introduction to the JEEG Agricultural Geophysics Special Issue
Allred, Barry J.; Smith, Bruce D.
2010-01-01
Near-surface geophysical methods have become increasingly important tools in applied agricultural practices and studies. The great advantage of geophysical methods is their potential rapidity, low cost, and spatial continuity when compared to more traditional methods of assessing agricultural land, such as sample collection and laboratory analysis. Agricultural geophysics investigations commonly focus on obtaining information within the soil profile, which generally does not extend much beyond 2 meters beneath the ground surface. Although the depth of interest oftentimes is rather shallow, the area covered by an agricultural geophysics survey can vary widely in scale, from experimental plots (10 s to 100 s of square meters), to farm fields (10 s to 100 s of hectares), up to the size of watersheds (10 s to 100 s of square kilometers). To date, three predominant methods—resistivity, electromagnetic induction (EMI), and ground-penetrating radar (GPR)—have been used to obtain surface-based geophysical measurements within agricultural settings. However, a recent conference on agricultural geophysics (Bouyoucos Conference on Agricultural Geophysics, September 8–10, 2009, Albuquerque, New Mexico; www.ag-geophysics.org) illustrated that other geophysical methods are being applied or developed. These include airborne electromagnetic induction, magnetometry, seismic, and self-potential methods. Agricultural geophysical studies are also being linked to ground water studies that utilize deeper penetrating geophysical methods than normally used.
Publications - GPR 2015-5 | Alaska Division of Geological & Geophysical
Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey electromagnetic and magnetic airborne geophysical survey data compilation Authors: Burns, L.E., Geoterrex-Dighem Graham, G.R.C., 2015, Livengood mining district electromagnetic and magnetic airborne geophysical survey
Publications - GPR 2015-6 | Alaska Division of Geological & Geophysical
Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey content DGGS GPR 2015-6 Click to enlarge Publication Details Title: Airborne magnetic geophysical survey ., Graham, Gina, and Goldak Airborne Surveys, 2015, Airborne magnetic geophysical survey of the Tanacross
Phillips Laboratory Geophysics Scholar Program
1993-09-30
research at Phillips Laboratory . Research sponsored by Air Force Geophysics Laboratory ...Geophysics Laboratory (now the Phillips Laboratory , Geophysics Directorate), United States Air Force for its sponsorship of this research through the Air ...September 1993 Approved for public release; distribution unlimited PHILLIPS LABORATORY Directorate of Geophysics AIR FORCE MATERIEL COMMAND
Geophysical methods in Geology. Second edition
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sharma, P.V.
This book presents an introduction to the methods of geophysics and their application to geological problems. The text emphasizes the broader aspects of geophysics, including the way in which geophysical methods help solve structural, correlational, and geochromological problems. Stress is laid on the principles and applications of methods rather than on instrumental techniques. This edition includes coverage of recent developments in geophysics and geology. New topics are introduced, including paleomagnetic methods, electromagnetic methods, microplate tectronics, and the use of multiple geophysical techniques.
Paillet, Frederick L.; Singhroy, V.H.; Hansen, D.T.; Pierce, R.R.; Johnson, A.I.
2002-01-01
Integration of geophysical data obtained at various scales can bridge the gap between localized data from boreholes and site-wide data from regional survey profiles. Specific approaches to such analysis include: 1) comparing geophysical measurements in boreholes with the same measurement made from the surface; 2) regressing geophysical data obtained in boreholes with water-sample data from screened intervals; 3) using multiple, physically independent measurements in boreholes to develop multivariate response models for surface geophysical surveys; 4) defining subsurface cell geometry for most effective survey inversion methods; and 5) making geophysical measurements in boreholes to serve as independent verification of geophysical interpretations. Integrated analysis of surface electromagnetic surveys and borehole geophysical logs at a study site in south Florida indicates that salinity of water in the surficial aquifers is controlled by a simple wedge of seawater intrusion along the coast and by a complex pattern of upward brine seepage from deeper aquifers throughout the study area. This interpretation was verified by drilling three additional test boreholes in carefully selected locations.
Geophysical monitoring technology for CO2 sequestration
NASA Astrophysics Data System (ADS)
Ma, Jin-Feng; Li, Lin; Wang, Hao-Fan; Tan, Ming-You; Cui, Shi-Ling; Zhang, Yun-Yin; Qu, Zhi-Peng; Jia, Ling-Yun; Zhang, Shu-Hai
2016-06-01
Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.
Solar-geophysical data number 499, March 1986, supplement
NASA Technical Reports Server (NTRS)
1986-01-01
This supplement contains the description and explanation of the data in the monthly publication Solar-Geophysical Data, compiled by the National Geophysical Data Center (NGDC) in Boulder, Colo., USA. Solar-Geophysical Data is intended to keep research workers informed on a timely schedule of the major events of solar activity and the associated interplanetary, ionospheric, radio propagation and other geophysical effects.
NASA Technical Reports Server (NTRS)
Glass, Charles E.; Boyd, Richard V.; Sternberg, Ben K.
1991-01-01
The overall aim is to provide base technology for an automated vision system for on-board interpretation of geophysical data. During the first year's work, it was demonstrated that geophysical data can be treated as patterns and interpreted using single neural networks. Current research is developing an integrated vision system comprising neural networks, algorithmic preprocessing, and expert knowledge. This system is to be tested incrementally using synthetic geophysical patterns, laboratory generated geophysical patterns, and field geophysical patterns.
Handbook of Agricultural Geophysics
USDA-ARS?s Scientific Manuscript database
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...
NASA Astrophysics Data System (ADS)
In recognition of the strong support and substantial contribution given by the American Geophysical Union to the American Geological Institute's Minority Participation Program, 16 of the 1982-83 scholarship recipients were designated ‘AGU Scholars.’ Because of a matching grant from the National Oceanographic and Atmospheric Administration to increase the number of minority students studying in fields related to the development of marine and coastal resources, five of this group were designated ‘AGU Sea Grant Scholars.’ The AGU Scholars, all of whom are following courses of study related to AGU's broad areas of interest, are Torin J. Edwards, a student of geophysics at the University of New Orleans; Gwendolyn Hofler, geophysics, Virginia State University; Jolecia Mitchell, environmental sciences, Howard University; Louis F. Montiel, geohydrology, Northern Arizona University; Alex M. Richards, geophysics, Northern Arizona University; Roxanne C. Rogers, geophysics, Colorado School of Mines; John F. Vargas, geophysics, University of Kansas; Toni M. VanDam, geophysics, University of Colorado; Edith G. Williams, geophysics, Stanford University; Saundra F. Willis, geosciences, California State University, Northridge; and Lacy B. Ward, geophysics, Virginia State University.
Publications - IC 52 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey ; Aerial Photography; Aeromagnetic; Aeromagnetic Data; Aeromagnetic Survey; Airborne Geophysical Survey Resistivity Data; Apparent Resistivity Map; Apparent Resistivity Survey; Arctic Deposit; Arsenic; Arsenopyrite
Publications - IC 51 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey Photography; Aeromagnetic; Aeromagnetic Data; Aeromagnetic Survey; Airborne Geophysical Survey; Alaska Data; Apparent Resistivity Map; Apparent Resistivity Survey; Arctic Deposit; Arsenic; Arsenopyrite
Publications - SR 61 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey K) Keywords Admiralty Island; Aeromagnetic Data; Aeromagnetic Survey; Airborne Geophysical Survey Dome; Conductivity Survey; Construction Materials; Copper; Core Drilling; Council; Crushed Gravel
Agricultural geophysics: Past/present accomplishments and future advancements
USDA-ARS?s Scientific Manuscript database
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...
The physics of the earth's core: An introduction
DOE Office of Scientific and Technical Information (OSTI.GOV)
Melchior, P.
1986-01-01
This book is a reference text providing information on physical topics of recent developments in internal geophysics. The text summarizes papers covering theoretical geophysics. Basic formulae, definitions and theorems are not explained in detail due to the limited space. The contents include applications to geodesy, geophysics, astronomy, astrophysics, geophysics and planetary physics. The formal contents include: The Earth's model; Thermodynamics; Hydrodynamics; Geomagnetism; Geophysical implications in the Earth's core.
Global status of and prospects for protection of terrestrial geophysical diversity.
Sanderson, Eric W; Segan, Daniel B; Watson, James E M
2015-06-01
Conservation of representative facets of geophysical diversity may help conserve biological diversity as the climate changes. We conducted a global classification of terrestrial geophysical diversity and analyzed how land protection varies across geophysical diversity types. Geophysical diversity was classified in terms of soil type, elevation, and biogeographic realm and then compared to the global distribution of protected areas in 2012. We found that 300 (45%) of 672 broad geophysical diversity types currently meet the Convention on Biological Diversity's Aichi Target 11 of 17% terrestrial areal protection, which suggested that efforts to implement geophysical diversity conservation have a substantive basis on which to build. However, current protected areas were heavily biased toward high elevation and low fertility soils. We assessed 3 scenarios of protected area expansion and found that protection focused on threatened species, if fully implemented, would also protect an additional 29% of geophysical diversity types, ecoregional-focused protection would protect an additional 24%, and a combined scenario would protect an additional 42%. Future efforts need to specifically target low-elevation sites with productive soils for protection and manage for connectivity among geophysical diversity types. These efforts may be hampered by the sheer number of geophysical diversity facets that the world contains, which makes clear target setting and prioritization an important next step. © 2015 Society for Conservation Biology.
Publications - SR 60 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey ; Aeromagnetic Survey; Airborne Geophysical Survey; Alaska Highway Corridor; Alaska Peninsula; Alaska, State of ; Bismuth; Chalcopyrite; Chandalar Mining District; Cleary Summit; Coal; Conductivity Survey; Construction
Publications - IC 46 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey ; Aeromagnetic; Aeromagnetic Survey; Airborne Geophysical Survey; Antimony; Arsenic; Arsenopyrite; Base Metals ; Electromagnetic Data; Electromagnetic Survey; Exploration; Fairbanks Mining District; Fort Knox Mine; Fortymile
A fractured rock geophysical toolbox method selection tool
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.
Publications - IC 60 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey (500.0 K) Keywords Admiralty Island; Aeromagnetic Data; Aeromagnetic Map; Aeromagnetic Survey; Airborne Geophysical Survey; Alaska Highway Corridor; Alaska Peninsula; Alaska, State of; Ambler; Ambler Mineral Belt
The Environmental Geophysics Web Site and Geophysical Decision Support System (GDSS)
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...
36 CFR 902.59 - Geological and geophysical information.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical information. 902.59 Section 902.59 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT... Geological and geophysical information. Any geological or geophysical information and data (including maps...
NASA Astrophysics Data System (ADS)
Webb, S. J.; Manzi, M.; Scheiber-Enslin, S. E.; Durrheim, R. J.; Jones, M. Q. W.; Nyblade, A.
2015-12-01
There are many challenges faced by geophysics students and academic staff in Africa that make it difficult to develop effective field and research programs. Challenges to conducting field work that have been identified, and that can be tackled are: lack of training on geophysical equipment and lack of exposure to field program design and implementation. To address these challenges, the AfricaArray/Wits Geophysics field school is designed to expose participants to a wide variety of geophysical instruments and the entire workflow of a geophysical project. The AA field school was initially developed for the geophysics students at the University of the Witwatersrand. However, by increasing the number of participants, we are able to make more effective use of a large pool of equipment, while addressing challenging geophysical problems at a remote field site. These additional participants are selected partially based on the likely hood of being able start a field school at their home institution. A good candidate would have access to geophysical equipment, but may not have knowledge of how to use it or how to effectively design surveys. These are frequently junior staff members or graduate students in leadership roles. The three week program introduces participants to the full geophysical field workflow. The first week is spent designing a geophysical survey, including determining the cost. The second week is spent collecting data to address a real geophysical challenge, such as determining overburden thickness, loss of ground features due to dykes in a mine, or finding water. The third week is spent interpreting and integrating the various data sets culminating in a final presentation. Participants are given all lecture material and much of the software is open access; this is done to encourage using the material at the home institution. One innovation has been to use graduate students as instructors, thus building a pool of talent that has developed the logistic and training skills necessary to implement field programs. Several geophysics field schools are being developed in Madagascar, Zimbabwe, Nigeria, Kenya, Uganda, Tanzania and Cameroon. We hope to enable some of our graduate students to help with these budding programs.
Publications - AR 2006 | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2006 main content DGGS AR 2006 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual
Publications - AR 2000 | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2000 main content DGGS AR 2000 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual
Publications - AR 2003 | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2003 main content DGGS AR 2003 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual
Publications - AR 2004 | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2004 main content DGGS AR 2004 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual
Publications - AR 2011-F | Alaska Division of Geological & Geophysical
project descriptions, in DGGS Staff, Alaska Division of Geological & Geophysical Surveys Annual Report Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2011-F main
Publications - AR 2010-E | Alaska Division of Geological & Geophysical
Communications FY11 project descriptions, in DGGS Staff, Alaska Division of Geological & Geophysical Surveys Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2010-E main
Publications - AR 2010-A | Alaska Division of Geological & Geophysical
FY11 project descriptions, in DGGS Staff, Alaska Division of Geological & Geophysical Surveys Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2010-A main
Publications - AR 2010-F | Alaska Division of Geological & Geophysical
project descriptions, in DGGS Staff, Alaska Division of Geological & Geophysical Surveys Annual Report Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2010-F main
NASA Astrophysics Data System (ADS)
Alperovich, Leonid; Averbuch, Amir; Eppelbaum, Lev; Zheludev, Valery
2013-04-01
Karst areas occupy about 14% of the world land. Karst terranes of different origin have caused difficult conditions for building, industrial activity and tourism, and are the source of heightened danger for environment. Mapping of karst (sinkhole) hazards, obviously, will be one of the most significant problems of engineering geophysics in the XXI century. Taking into account the complexity of geological media, some unfavourable environments and known ambiguity of geophysical data analysis, a single geophysical method examination might be insufficient. Wavelet methodology as whole has a significant impact on cardinal problems of geophysical signal processing such as: denoising of signals, enhancement of signals and distinguishing of signals with closely related characteristics and integrated analysis of different geophysical fields (satellite, airborne, earth surface or underground observed data). We developed a three-phase approach to the integrated geophysical localization of subsurface karsts (the same approach could be used for following monitoring of karst dynamics). The first phase consists of modeling devoted to compute various geophysical effects characterizing karst phenomena. The second phase determines development of the signal processing approaches to analyzing of profile or areal geophysical observations. Finally, at the third phase provides integration of these methods in order to create a new method of the combined interpretation of different geophysical data. In the base of our combine geophysical analysis we put modern developments in the wavelet technique of the signal and image processing. The development of the integrated methodology of geophysical field examination will enable to recognizing the karst terranes even by a small ratio of "useful signal - noise" in complex geological environments. For analyzing the geophysical data, we used a technique based on the algorithm to characterize a geophysical image by a limited number of parameters. This set of parameters serves as a signature of the image and is to be utilized for discrimination of images containing karst cavity (K) from the images non-containing karst (N). The constructed algorithm consists of the following main phases: (a) collection of the database, (b) characterization of geophysical images, (c) and dimensionality reduction. Then, each image is characterized by the histogram of the coherency directions. As a result of the previous steps we obtain two sets K and N of the signatures vectors for images from sections containing karst cavity and non-karst subsurface, respectively.
Geophysical Institute. Biennial report, 1993-1994
DOE Office of Scientific and Technical Information (OSTI.GOV)
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.
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
NASA Astrophysics Data System (ADS)
Lowrie, William
1997-10-01
This unique textbook presents a comprehensive overview of the fundamental principles of geophysics. Unlike most geophysics textbooks, it combines both the applied and theoretical aspects to the subject. The author explains complex geophysical concepts using abundant diagrams, a simplified mathematical treatment, and easy-to-follow equations. After placing the Earth in the context of the solar system, he describes each major branch of geophysics: gravitation, seismology, dating, thermal and electrical properties, geomagnetism, paleomagnetism and geodynamics. Each chapter begins with a summary of the basic physical principles, and a brief account of each topic's historical evolution. The book will satisfy the needs of intermediate-level earth science students from a variety of backgrounds, while at the same time preparing geophysics majors for continued study at a higher level.
NASA Astrophysics Data System (ADS)
Drahor, Mahmut G.; Berge, Meriç A.
2017-01-01
Integrated geophysical investigations consisting of joint application of various geophysical techniques have become a major tool of active tectonic investigations. The choice of integrated techniques depends on geological features, tectonic and fault characteristics of the study area, required resolution and penetration depth of used techniques and also financial supports. Therefore, fault geometry and offsets, sediment thickness and properties, features of folded strata and tectonic characteristics of near-surface sections of the subsurface could be thoroughly determined using integrated geophysical approaches. Although Ground Penetrating Radar (GPR), Electrical Resistivity Tomography (ERT) and Seismic Refraction Tomography (SRT) methods are commonly used in active tectonic investigations, other geophysical techniques will also contribute in obtaining of different properties in the complex geological environments of tectonically active sites. In this study, six different geophysical methods used to define faulting locations and characterizations around the study area. These are GPR, ERT, SRT, Very Low Frequency electromagnetic (VLF), magnetics and self-potential (SP). Overall integrated geophysical approaches used in this study gave us commonly important results about the near surface geological properties and faulting characteristics in the investigation area. After integrated interpretations of geophysical surveys, we determined an optimal trench location for paleoseismological studies. The main geological properties associated with faulting process obtained after trenching studies. In addition, geophysical results pointed out some indications concerning the active faulting mechanism in the area investigated. Consequently, the trenching studies indicate that the integrated approach of geophysical techniques applied on the fault problem reveals very useful and interpretative results in description of various properties of faulting zone in the investigation site.
Marine Magnetic Data Holdings of World Data Center-a for Marine Geology and Geophysics
NASA Technical Reports Server (NTRS)
Sharman, George F.; Metzger, Dan
1992-01-01
The World Data Center-A for Marine Geology and Geophysics is co-located with the Marine Geology & Geophysical Data Center, Boulder, CO. Fifteen million digital marine magnetic trackline measurements are managed within the GEOphysical DAta System (GEODAS). The bulk of these data were collected with proton precision magnetometers under Transit Satellite navigational control. Along-track sampling averages about 1 sample per kilometer, while spatial density, a function of ship's track and survey pattern, range from 4 to 0.02 data points/sq. km. In the near future, the entire geophysical data set will be available on CD-ROM. The Marine Geology and Geophysics Division (World Data Center-A for MGG), of the National Geophysical Data Center, handles a broad spectrum of marine geophysical data, including measurements of bathymetry, magnetics, gravity, seismic reflection subbottom profiles, and side-scan images acquired by ships throughout the world's oceans. Digital data encompass the first three, while the latter two are in analog form, recorded on 35mm microfilm. The marine geophysical digital trackline data are contained in the GEODAS data base which includes 11.6 million nautical miles of cruise trackline coverage contributed by more than 70 organizations worldwide. The inventory includes data from 3206 cruises with 33 million digital records and indexing to 5.3 million track miles of analog data on microfilm.
Research and career opportunities in the geophysical sciences for physics students
NASA Astrophysics Data System (ADS)
Nyblade, Andrew
2008-10-01
The field of geophysics involves using most branches of physics to investigate the physical structure and process that characterize the solid and fluid parts of our planet. Major advances in geophysics have come about from physicists crossing disciplinary boundaries and using their skills and knowledge to address first-order problems about the nature and structure of our planet and how the planet has changed over time. Indeed, some of the largest scientific breakthroughs in geophysics have come from physicists. As a way to introduce students to the field of geophysics and to provide them with information about research and career opportunities in geophysics, this talk will focus on one area of geophysics, seismology. This is an area of geophysics that has not only been instrumental in advancing our understanding of solid Earth structure and processes, but one that also has an applied side used for oil, gas and mineral exploration, as well as for environmental work. Examples of research projects involving seismic wave propagation and tomographic imaging will be presented, along the short descriptions of career opportunities in industry, government and academic institutions. In collaboration with Solomon Bililign, North Carolina A&T State University.
NASA Astrophysics Data System (ADS)
Mussett, Alan E.; Aftab Khan, M.; Button, Illustrated By Sue
2000-12-01
Looking Into the Earth comprehensively describes the principles and applications of both `global' and `exploration' geophysics on all scales. It forms an introduction to geophysics suitable for those who do not necessarily intend to become professional geophysicists, including geologists, civil engineers, environmental scientists, and field archaeologists. The book is organised into two parts: Part 1 describes the geophysical methods, while Part 2 illustrates their use in a number of extended case histories. Mathematical and physical principles are introduced at an elementary level, and then developed as necessary. Student questions and exercises are included at the end of each chapter. The book is aimed primarily at introductory and intermediate university students taking courses in geology, earth science, environmental science, and engineering. It will also form an excellent introductory textbook in geophysics departments, and will help practising geologists, archaeologists and engineers understand what geophysics can offer their work. Accessible to students with little background in maths and physics Covers both global and applied geophysics Well illustrated and contains many student exercises and case studies Written by experienced teachers of geophysics
NASA Astrophysics Data System (ADS)
Rakhmenkulova, I. F.
2016-12-01
How to nourish young brilliant geophysicists? Here are the tips: We teach them as physicists (at the Department of Physics, together with students majoring in physics). Students have special facilities in field work, using most modern geophysical equipment. They can participate in real projects on applied geophysics during their studies. They attend special seminars and conferences for both young professionals and full-fledged scientists. Their English Language Program is focused on geophysical terminology. There are four specialties at Geology and Geophysics Department of Novosibirsk State University: Geophysics, Geochemistry, Geology, and Geochemistry of Oil and Gas. However, the curriculum for geophysicists is absolutely different from other specialties. Mathematics, physics and laboratory work are given at the Department of Physics (together with students majoring in physics). All the necessary geological subjects are also studied (including field work). During all period of their study the students work part time at many geophysical institutions. The equipment is both traditional and most modern, created at the Institute of Oil and Gas Geophysics. The students present the result of their field work and laboratory experiments in many seminars and conferences. For example, there is a traditional annual conference in Shira, Khakassia, for young professionals. Every year the Seminar in Geodynamics, Geophysics and Geomechanics is held in the Altay Mountains (Denisova Cave Camp). This Seminar was organized by the late Sergey Goldin, the Director of the Institute of Geophysics, the Head of the Chair of Geophysics, a Member of the Russian Academy of Sciences. In July 2016 this Seminar was devoted to 80's birth anniversary of Sergey Goldin. Several students of geophysics presented the results of their work there. Next year the seminar is supposed to be international. A special attention is given to the English course lasting for 5 years. The students learn general English at first, but then their study is focused on English for geophysicists, including special terminology. This is done for successful integration of young geophysicists into international professional community. Many GGD students are members of international professional organizations, such as SEG, SPE, AGU and others.
Publications - SR 51 | Alaska Division of Geological & Geophysical Surveys
& Geophysical Surveys Comments: Your help is crucial in the compilation of future Alaska Minerals Resources; Fluorine; Geophysics; Germanium; Gold; Heap Leach; Iron; Jade; Lead; Lode; Mercury; Minerals
Publications - NL 2006-1 | Alaska Division of Geological & Geophysical
Liberty Bell, western Bonnifield mining district geophysical tract Authors: DGGS Staff, and Athey, J.E inventory Liberty Bell, western Bonnifield mining district geophysical tract: Alaska Division of Geological
NASA Astrophysics Data System (ADS)
Graedel, T. E.
The most visible activity of the American Geophysical Union is its publication of scientific journals. There are eight of these: Journal of Geophysical Research—Space Physics (JGR I), Journal of Geophysical Research—Solid Earth (JGR II), Journal of Geophysical Research—Oceans and Atmospheres (JGR III), Radio Science (RS), Water Resources Research (WRR), Geophysical Research Letters (GRL), Reviews of Geophysics and Space Physics (RGSP), and the newest, Tectonics.AGU's journals have established solid reputations for scientific excellence over the years. Reputation is not sufficient to sustain a high quality journal, however, since other factors enter into an author's decision on where to publish his or her work. In this article the characteristics of AGU's journals are compared with those of its competitors, with the aim of furnishing guidance to prospective authors and a better understanding of the value of the products to purchasers.
Multiscale geophysical imaging of the critical zone
Parsekian, Andy; Singha, Kamini; Minsley, Burke J.; Holbrook, W. Steven; Slater, Lee
2015-01-01
Details of Earth's shallow subsurface—a key component of the critical zone (CZ)—are largely obscured because making direct observations with sufficient density to capture natural characteristic spatial variability in physical properties is difficult. Yet this inaccessible region of the CZ is fundamental to processes that support ecosystems, society, and the environment. Geophysical methods provide a means for remotely examining CZ form and function over length scales that span centimeters to kilometers. Here we present a review highlighting the application of geophysical methods to CZ science research questions. In particular, we consider the application of geophysical methods to map the geometry of structural features such as regolith thickness, lithological boundaries, permafrost extent, snow thickness, or shallow root zones. Combined with knowledge of structure, we discuss how geophysical observations are used to understand CZ processes. Fluxes between snow, surface water, and groundwater affect weathering, groundwater resources, and chemical and nutrient exports to rivers. The exchange of gas between soil and the atmosphere have been studied using geophysical methods in wetland areas. Indirect geophysical methods are a natural and necessary complement to direct observations obtained by drilling or field mapping. Direct measurements should be used to calibrate geophysical estimates, which can then be used to extrapolate interpretations over larger areas or to monitor changing processes over time. Advances in geophysical instrumentation and computational approaches for integrating different types of data have great potential to fill gaps in our understanding of the shallow subsurface portion of the CZ and should be integrated where possible in future CZ research.
Covariant Structure of Models of Geophysical Fluid Motion
NASA Astrophysics Data System (ADS)
Dubos, Thomas
2018-01-01
Geophysical models approximate classical fluid motion in rotating frames. Even accurate approximations can have profound consequences, such as the loss of inertial frames. If geophysical fluid dynamics are not strictly equivalent to Newtonian hydrodynamics observed in a rotating frame, what kind of dynamics are they? We aim to clarify fundamental similarities and differences between relativistic, Newtonian, and geophysical hydrodynamics, using variational and covariant formulations as tools to shed the necessary light. A space-time variational principle for the motion of a perfect fluid is introduced. The geophysical action is interpreted as a synchronous limit of the relativistic action. The relativistic Levi-Civita connection also has a finite synchronous limit, which provides a connection with which to endow geophysical space-time, generalizing Cartan (1923). A covariant mass-momentum budget is obtained using covariance of the action and metric-preserving properties of the connection. Ultimately, geophysical models are found to differ from the standard compressible Euler model only by a specific choice of a metric-Coriolis-geopotential tensor akin to the relativistic space-time metric. Once this choice is made, the same covariant mass-momentum budget applies to Newtonian and all geophysical hydrodynamics, including those models lacking an inertial frame. Hence, it is argued that this mass-momentum budget provides an appropriate, common fundamental principle of dynamics. The postulate that Euclidean, inertial frames exist can then be regarded as part of the Newtonian theory of gravitation, which some models of geophysical hydrodynamics slightly violate.
Sustainable urban development and geophysics
NASA Astrophysics Data System (ADS)
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 investigated [2]. The first objective of urban geophysics is to study systematically the geophysical fields in cities, searching for principles and processes governing the intensity and patterns of variation of the geophysical properties, as well as the potential consequences on the biosphere. Secondly, geophysics has already been found to be a useful tool for subsurface detection and investigation, hazard mitigation, and assessment of environmental contamination. Geophysicists have documented numerous cases of successful applications of geophysical techniques to solve problems related to hazard mitigation, safeguarding of lifeline infrastructure and urban gateways (air- and sea-ports, railway and highway terminals), archaeological and heritage surveys, homeland security, urban noise control, water supplies, sanitation and solid waste management etc. In contrast to conventional geophysical exploration, the undertaking of geophysical surveys in an urban setting faces many new challenges and difficulties. First of all, the ambient cultural noise in cities caused by traffic, electromagnetic radiation and electrical currents often produce undesirably strong interference with geophysical measurements. Secondly, subsurface surveys in an urban area are often targeted at the uppermost several metres of the ground, which are the most heterogeneous layers with many man-made objects. Thirdly, unlike conventional geophysical exploration which requires resolution in the order of metres, many urban geophysical surveys demand a resolution and precision in the order of centimetres or even millimetres. Finally restricted site access and limited time for conducting geophysical surveys, regulatory constraints, requirements for traffic management and special logistical arrangements impose additional difficulties. All of these factors point to the need for developing innovative research methods and geophysical instruments suitable for use in urban settings. This special issue on 'Sustainable urban development and geophysics' in Journal of Geophysics and Engineering is a response to the call for the development of novel geophysical techniques especially applicable to city settings. It consists of 11 papers which are selected and expanded from a collection of papers presented to the special sessions on 'Sustainable Urban Development and Geophysics' (U14A, U15A, and U41B) in the Union section of the Western Pacific Geophysics Meeting held in Beijing, China, on 22-27 July 2006 [3]. This indicates that new and innovative geophysical applications in urban settings have emerged, and these innovations may be potentially useful for the planning, implementation, and maintenance of urban infrastructure systems. These 11 research papers can be divided into three groups: (1) geophysics and urban infrastructure; (2) geophysics and urban environment; and (3) geophysical investigations associated with geological hazards. The first group of papers focuses on urban infrastructure. Fred Stumm et al reported a geohydrologic assessment of fractured crystalline bedrock with borehole radar in Manhattan, New York in preparation for the construction of a new water tunnel. Using GPR, Xie et al conducted a quality control study of the walls of the river-crossing highway tunnel in Shanghai. For the same purpose, S Liu et al investigated the effect of concrete cracks on GPR signatures using a numerical simulation technique. Sun et al, using seismic surface waves, investigated road beds and the degree of weathering of the marble fence in the Forbidden City, Beijing. In the second group of papers, using a numerical simulation technique, L Liu et al studied the effect of a building coordinate error on sound wave propagation with the aim of locating sound sources in urban settings. Chan et al studied the abundance of radio elements in weathered igneous bedrock in Hong Kong for the purpose of the promotion of public health in the urban environment. The third group includes five papers on geo-hazards. The three papers by B Zhao et al and Z Zhao et al address the problem of earthquake strong ground motion in urban regions using case studies from Osaka, Japan and the city of Yinchuan, China. The other two papers study the geological hazard of surface subsidence using geophysical tools: G Leucci reported a comprehensive study in Nardo, Italy, while Kim et al reported a similar case study for a small city in South Korea. One striking feature of all the papers in this special issue is that multiple authors with at least 3 co-authors wrote the majority of the papers, which is an indication of strong team work and interdisciplinary collaboration. This is essential for the successful application of geophysical science and technology in tackling a variety of engineering and environmental problems for the urban setting. The only sole author, Dr Leucci, expressed deep gratitude in his acknowledgements to his team members who carried out substantial parts of the data acquisition. We are pleased to present this special issue to the engineering and environmental geophysics community and hope that it can serve as a snapshot of the current state-of-the-art studies in urban geophysics. References [1] United Nations 1990 World Demographic Estimates and Projections (1950-2025) (New York: Press of United Nations) [2] Chen Y, L-S Chan and S Yu 2003 J. Geodesy & Geodynamics 23 1-4 (in Chinese) [3] American Geophysics Union 2006 Eos Trans. AGU 87 (36)
Penaluna, Brooke E.; Railsback, Steve F.; Dunham, Jason B.; Johnson, S.; Bilby, Richard E.; Skaugset, Arne E.
2015-01-01
The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams.
Langenheim, V.E.; Hildenbrand, T.G.
1997-01-01
The Commerce geophysical lineament is a northeast-trending magnetic and gravity feature that extends from central Arkansas to southern Illinois over a distance of ???400 km. It is parallel to the trend of the Reelfoot graben, but offset ???40 km to the northwest of the western margin of the rift floor. Modeling indicates that the source of the aeromagnetic and gravity anomalies is probably a mafic dike swarm. The age of the source of the Commerce geophysical lineament is not known, but the linearity and trend of the anomalies suggest a relationship with the Reelfoot rift, which has undergone episodic igneous activity. The Commerce geophysical lineament coincides with several topographic lineaments, movement on associated faults at least as young as Quaternary, and intrusions of various ages. Several earthquakes (Mb > 3) coincide with the Commerce geophysical lineament, but the diversity of associated focal mechanisms and the variety of surface structural features along the length of the Commerce geophysical lineament obscure its relation to the release of present-day strain. With the available seismicity data, it is difficult to attribute individual earthquakes to a specific structural lineament such as the Commerce geophysical lineament. However, the close correspondence between Quaternary faulting and present-day seismicity along the Commerce geophysical lineament is intriguing and warrants further study.
NASA Astrophysics Data System (ADS)
Kozhushko, A. A.; Pahotin, A. N.; Mal'tsev, V. N.; Bojarnikova, L. V.; Stepanova, E. P.
2018-04-01
The technology of carrying out various geophysical studies of oil wells using a carrying well-logging cable for the delivery of geophysical instruments and equipment is considered in the article. The relevance of the topic results from the need to evaluate the effect of well-logging cable stretching in the well under the influence of its own mass and mass of geophysical instruments and equipment on the accuracy and adequacy geophysical studies. Calculation formulas for determining the well-logging cable stretching under the influence of the geophysical tools and equipment mass without taking into account and taking into account the influence of the carrying well-logging cable mass are also presented. For three types of carrying well-logging cables, calculations were made of their stretching in the oil well under the mass of geophysical instruments and equipment and its own mass, depending on the depth of the investigated well. The analysis of the obtained results made it possible to numerically evaluate the extension of the carrying well-logging cable depending on the depth of the investigated well and by correcting the obtained results it allows to provide the required depth accuracy and reliability of the interpreted results of the geophysical studies.
International Symposium on Airborne Geophysics
NASA Astrophysics Data System (ADS)
Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi
2006-05-01
Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.
Geophysical Investigations in the Caucasus (1925 - 2012): Initial, Basic and Modern Stages
NASA Astrophysics Data System (ADS)
Eppelbaum, L. V.
2012-04-01
The Caucasian Mountains occupy an area of about 440,000 km2. A number of important mineral resources are concentrated there. Geophysical data on the geological structure of Caucasus can shed light on the basic principles of evolution of the Earth, the distribution of minerals and seismic activity. However, geophysical surveys under complex conditions are generally riddled by poor accessibility to certain mountainous regions, the unevenness of observation surfaces, as well as by a great variety and frequent changes of tectonic structures and geological bodies with variable physical properties. These factors either restrict geophysical surveys in difficult environments or confine the scope of useful information drawn from the results obtained. This has led to the development of special techniques in geophysical surveys, data processing and interpretation that draws heavily on the experience accumulated in the specific conditions of these mountainous regions. First applied geophysical observations in the Caucasus region - thermal measurements in boreholes - were carried out by Bazevich (1881) in the Absheron Peninsula. At the same time, start of the initial stage is usually referred to as the mid 20-s of the XX century, when the rare, but systematic geophysical observations (mainly gravity and magnetic) were begun in some Caucasian areas. Somewhat later began to apply the resistivity method. Mid 30-s is characterized by the beginning of application of borehole geophysics and seismic prospecting. The marine seismics firstly in the former Soviet Union was tested in the Caspian Sea. In general, the initial stage is characterized by slow, but steady rise (except during World War II) lasted until 1960. A basic stage (1960-1991) is characterized by very intensive employment of geophysical methods (apparently, any possible geophysical methods were tested in this region). At this time the Caucasus region is considered in the former Soviet Union as a geophysical polygon for testing different geophysical methods and methodologies in complicated environments. Airborne magnetic and gravity surveys covered all the Caucasus, regional seismic and magnetotelluric studies were used as reference profiles for deep structure investigation. Numerous effective applications of geophysical methods for searching ore, oil&gas deposits, building raw, fresh water localization, solving engineering, etc. was demonstrated. Seismological investigations (including different methods) were widely applied throughout the entire Caucasian region. Satellite geophysical examinations were successfully combined with other methods. Finally, destruction of the former Soviet Union in 1991 (beginning of the modern stage) caused a sharp common decreasing of the geophysical activity in this region. Only foreign oil-&gas companies (mainly American and England) demonstrated some industrial geophysical activity basically in the Caspian Sea. In the last few years the situation began to straighten out, especially in the field of seismology. This presentation is based of the author's experience (e.g., Eppelbaum, 1989, 1991, 2009; Eppelbaum et al., 1987; Eppelbaum and Finkelstein, 1998; Eppelbaum and Khesin, 1988, 1992, 2002, 2004, 2011, 2012; Eppelbaum and Mishne, 2011; Eppelbaum et al., 2003, 2004; Khesin et al., 1988, 1993a, 1993b, 1996, 1997; Khesin and Eppelbaum, 1986, 1994, 1997, 2007; Pilchin and Eppelbaum, 1997, 2011) and corresponding publications and reviews of other authors.
IDIMS/GEOPAK: Users manual for a geophysical data display and analysis system
NASA Technical Reports Server (NTRS)
Libert, J. M.
1982-01-01
The application of an existing image analysis system to the display and analysis of geophysical data is described, the potential for expanding the capabilities of such a system toward more advanced computer analytic and modeling functions is investigated. The major features of the IDIMS (Interactive Display and Image Manipulation System) and its applicability for image type analysis of geophysical data are described. Development of a basic geophysical data processing system to permit the image representation, coloring, interdisplay and comparison of geophysical data sets using existing IDIMS functions and to provide for the production of hard copies of processed images was described. An instruction manual and documentation for the GEOPAK subsystem was produced. A training course for personnel in the use of the IDIMS/GEOPAK was conducted. The effectiveness of the current IDIMS/GEOPAK system for geophysical data analysis was evaluated.
NASA Astrophysics Data System (ADS)
Sőrés, László
2013-04-01
INSPIRE is a European directive to harmonize spatial data in Europe. Its' aim is to establish a transparent, multidisciplinary network of environmental information by using international standards and OGC web services. Spatial data themes defined in the annex of the directive cover 34 domains that are closely bundled to environment and spatial information. According to the INSPIRE roadmap all data providers must setup discovery, viewing and download services and restructure data stores to provide spatial data as defined by the underlying specifications by 2014 December 1. More than 3000 institutions are going to be involved in the progress. During the data specification process geophysics as an inevitable source of geo information was introduced to Annex II Geology. Within the Geology theme Geophysics is divided into core and extended model. The core model contains specifications for legally binding data provisioning and is going to be part of the Implementation Rules of the INSPIRE directives. To minimize the work load of obligatory data transformations the scope of the core model is very limited and simple. It covers the most essential geophysical feature types that are relevant in economic and environmental context. To fully support the use cases identified by the stake holders the extended model was developed. It contains a wide range of spatial object types for geophysical measurements, processed and interpreted results, and wrapper classes to help data providers in using the Observation and Measurements (O&M) standard for geophysical data exchange. Instead of introducing the traditional concept of "geophysical methods" at a high structural level the data model classifies measurements and geophysical models based on their spatial characteristics. Measurements are classified as geophysical station (point), geophysical profile (curve) and geophysical swath (surface). Generic classes for processing results and interpretation models are curve model (1D), surface model (2D), and solid model (3D). Both measurements and models are derived from O&M sampling features that may be linked to sampling procedures and observation results. Geophysical products are output of complex procedures and can precisely be described as chains of consecutive O&M observations. For describing geophysical processes and results the data model both supports the use of OGC standard XML encoding (SensorML, SWE, GML) and traditional industry standards (SPS, UKOOA, SEG formats). To control the scope of the model and to harmonize terminology an initial set of extendable code lists was developed. The attempt to create a hierarchical SKOS vocabulary of terms for geophysical methods, resource types, processes, properties and technical parameters was partly based on the work done in the eContentPlus GEOMIND project. The result is far from being complete, and the work must be continued in the future.
Foundations of geophysics. [College textbook
DOE Office of Scientific and Technical Information (OSTI.GOV)
Scheidegger, A.E.
1976-01-01
The following subjects are covered/: geography, geodesy, and geology; seismology, gravity, and the Earth's interior; magnetic and electrical properties of the earth; thermicity of the earth and related subjects; tectonophysics; geophysical exploration; geohydrology; physical oceanography; physical meteorology; and engineering geophysics. (MHR)
Geophysics applications in critical zone science: emerging topics
USDA-ARS?s Scientific Manuscript database
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...
Electromagnetic geophysical observation with controlled source
NASA Astrophysics Data System (ADS)
Hachay, Olga; Khachay, Oleg
2016-04-01
In the paper the new theoretical and methodical approaches are examined for detailed investigations of the structure and state of the geological medium, and its behavior as a dynamic system in reaction to external man-made influences. To solve this problem it is necessary to use geophysical methods that have sufficient resolution and that are built on more complicated models than layered or layered-block models. One of these methods is the electromagnetic induction frequency-geometrical method with controlled sources. Here we consider new approaches using this method for monitoring rock shock media by means of natural experiments and interpretation of the practical results. That method can be used by oil production in mines, where the same events of non stability can occur. The key ideas of twenty first century geophysics from the point of view of geologist academician A.N. Dmitrievskiy [Dmitrievskiy, 2009] are as follows. "The geophysics of the twenty first century is an understanding that the Earth is a self-developing, self-supporting geo-cybernetic system, in which the role of the driving mechanism is played by the field gradients; the evolution of geological processes is a continuous chain of transformations and the interaction of geophysical fields in the litho- hydro- and atmosphere. The use of geophysical principles of a hierarchical quantum of geophysical space, non-linear effects, and the effects of reradiating geophysical fields will allow the creation of a new geophysics. The research, in which earlier only pure geophysical processes and technologies were considered, nowadays tends to include into consideration geophysical-chemical processes and technologies. This transformation will allow us to solve the problems of forecasting geo-objects and geo-processes in previously unavailable geological-technological conditions." The results obtained allow us to make the following conclusions, according to the key ideas of academician A.N. Dmitrievskiy: the rock massif is a multi-ranked hierarchical structure. Research of the massif state dynamics, its structure and the effects of self-organization in it can be provided by geophysical methods, which are built upon the model of such medium. The use of the planshet multi-level induction electromagnetic method with a controlled source of excitation and a corresponding method of processing and interpretation has allowed us to reveal the disintegration zones which are indicators of massif stability and understand the causes of low productivity of oil recovery from boreholes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Robinson, E.S.
1988-01-01
An introduction to geophysical methods used to explore for natural resources and to survey earth's geology is presented in this volume. It is suitable for second-and third-year undergraduate students majoring in geology or engineering and for professional engineering and for professional engineers and earth scientists without formal instruction in geophysics. The author assumes the reader is familiar with geometry, algebra, and trigonometry. Geophysical exploration includes seismic refraction and reflection surveying, electrical resistivity and electromagnetic field surveying, and geophysical well logging. Surveying operations are described in step-by-step procedures and are illustrated by practical examples. Computer-based methods of processing and interpreting datamore » as well as geographical methods are introduced.« less
Fiber optic geophysical sensors
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.
Merging information in geophysics: the triumvirat of geology, geophysics, and petrophysics
NASA Astrophysics Data System (ADS)
Revil, A.
2016-12-01
We know that geophysical inversion is non-unique and that many classical regularization techniques are unphysical. Despite this, we like to use them because of their simplicity and because geophysicists are often afraid to bias the inverse problem by introducing too much prior information (in a broad sense). It is also clear that geophysics is done on geological objects that are not random structures. Spending some time with a geologist in the field, before organizing a field geophysical campaign, is always an instructive experience. Finally, the measured properties are connected to physicochemical and textural parameters of the porous media and the interfaces between the various phases of a porous body. .Some fundamental parameters may control the geophysical observtions or their time variations. If we want to improve our geophysical tomograms, we need to be risk-takers and acknowledge, or rather embrqce, the cross-fertilization arising by coupling geology, geophysics, and ptrophysics. In this presentation, I will discuss various techniques to do so. They will include non-stationary geostatistical descriptors, facies deformation, cross-coupled petrophysical properties using petrophysical clustering, and image-guided inversion. I will show various applications to a number of relevant cases in hydrogeophysics. From these applications, it may become clear that there are many ways to address inverse or time-lapse inverse problems and geophysicists have to be pragmatic regarding the methods used depending on the degree of available prior information.
NASA Astrophysics Data System (ADS)
Patton, Margaret Maurine
Fort Pierre Chouteau in present day South Dakota was the most important fur trading post of the American Fur Company in the 1830s, serving as a regional hub for the fur trade. The Fort was sold to the U.S. Military in 1855 for use as a base in the Sioux Wars but was abandoned in 1856. Geophysical surveys and previous excavations indicate evidence of both occupations. Geophysics is an important tool for determining the extent of archaeological sites, yet the relationships between geophysical anomalies and excavation features may not be readily evident. Initial geophysical surveys (Kvamme 2007) were completed to determine the extent of the fur trading Fort, and additional surveys in August 2012 used magnetometry and electrical resistance to determine if evidence of military structures exists outside of the Fort. This study examines connections between excavation features and geophysical anomalies in order to better interpret anomalies inside the Fort palisade. The palisade builder's trench, adobe pavement, post holes, and unknown structures are characterized through the analysis of the excavations and anomalies. The location of one of the military structures outside of the palisade is also identified. As many sites have histories of excavations prior to any geophysical surveys, combining the two sets of information is important in order to more fully understand site layout and the archaeological causes of geophysical anomalies.
Student Research Projects in Geophysics Through a Consortium of Undergraduate Geology Departments
NASA Astrophysics Data System (ADS)
Kroeger, G. C.
2003-12-01
Beginning in 1987, and continuing to the present, the Keck Geology Consortium, a group of 12 undergraduate institutions, has sponsored a series of summer research projects. These projects typically involve from 9 to 12 students and 3 to 4 faculty members and consist of a 4 to 5 week summer research program followed by continuation of the research at the students' home institutions, often as a senior thesis. Many of these projects have included extensive field and laboratory geophysical components. In order for students to carry out successful research projects in geophysics, several hurdles have to be cleared. Frequently these students have not had a formal course in geophysics, so although they may have strong geologic and quantitative skills, there is usually the need for a concentrated classroom immersion in the geophysical theory and methods related to the project. Field geophysics projects are labor intensive, so it is common for a group of three or more students to produce only one or two complete data sets in the course of the summer program. Generating individualized projects so that students feel ownership of their thesis research can be challenging. Most of the departments do not have a geophysicist on the faculty, so follow-up support for the student research involves continued long-distance collaboration between project directors, students and sponsoring faculty. The impact of the internet on this collaboration cannot be overstated. Finally, diverse computing environments at the participating institutions were a significant problem in the early years. Migration of geophysical software to Windows from Unix, and the widespread availability of Linux has mitigated these problems in recent years. The geophysical components of these projects have been largely successful. A series of vignettes is presented showing the range and nature of geophysical projects that have been carried out. In addition to anecdotal evidence of student satisfaction, there is quantitative evidence of success. A substantial number of students have gone on to graduate work in geophysics. Of those students who did not pursue geophysics, a substantial fraction has pursued graduate work or careers in other areas of quantitative geosciences.
Moving Beyond IGY: An Electronic Geophysical Year (eGY) Concept
NASA Astrophysics Data System (ADS)
Baker, D. N.; Barton, C. E.; Rodger, A. S.; Thompson, B. J.; Fraser, B.; Papitashvili, V.
2003-12-01
During the International Geophysical Year (1957-1958), member countries established many new geophysical observatories pursuing the major IGY objectives - to collect geophysical data as widely as possible and to provide free access to these data for all scientists around the globe. Today, geophysics has attained a rather good understanding within traditional regions, i.e., the atmosphere, ionosphere, magnetosphere, and other such geospheres. At the same time, it has become clear that much of the new and important science is coming from the studies of interfaces and coupling between geospheres. Thus, if geophysical data are made `'transparently'' available to a much wider range of scientists and students than to those who do the observations, then new and exciting discoveries can be expected. An International Association of Geomagnetic and Aeronomy (IAGA) task force, recognizing that a key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories, proposes that for the 50th anniversary of IGY, the worldwide scientific community should endorse and promote an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the IGY in 2007-2008 and provide a forward impetus to geophysics in 21st century, similar to that provided by the IGY fifty years ago. The IAGA task force strongly advocates: (1) Securing permission and release of existing data; (2) Creating access to information; and (3) Conversion of relevant analog data to digital form. The eGY concept embraces all available and upcoming geophysical data (e.g., atmospheric, ionospheric, geomagnetic, gravity, etc.) through the establishment of a series of virtual geophysical observatories now being `'deployed'' in cyberspace. The eGY concept is modern, global, and timely; it is attractive, pragmatic, and affordable. The eGY is based on the existing and continually developing computing/networking technologies (e.g., XML, Semantic Web, etc.) and international cyber infrastructure. Moreover, the International Union of Geodesy and Geophysics (IUGG) has supported the eGY concept, which can smoothly be incorporated into various existing `'International Year'' initiatives - such as the International Polar Year, International Heliophysical Year, or International Year of the Planet Earth.
Agricultural Geophysics: Past, present, and future
USDA-ARS?s Scientific Manuscript database
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...
Unleashing Geophysics Data with Modern Formats and Services
NASA Astrophysics Data System (ADS)
Ip, Alex; Brodie, Ross C.; Druken, Kelsey; Bastrakova, Irina; Evans, Ben; Kemp, Carina; Richardson, Murray; Trenham, Claire; Wang, Jingbo; Wyborn, Lesley
2016-04-01
Geoscience Australia (GA) is the national steward of large volumes of geophysical data extending over the entire Australasian region and spanning many decades. The volume and variety of data which must be managed, coupled with the increasing need to support machine-to-machine data access, mean that the old "click-and-ship" model delivering data as downloadable files for local analysis is rapidly becoming unviable - a "big data" problem not unique to geophysics. The Australian Government, through the Research Data Services (RDS) Project, recently funded the Australian National Computational Infrastructure (NCI) to organize a wide range of Earth Systems data from diverse collections including geoscience, geophysics, environment, climate, weather, and water resources onto a single High Performance Data (HPD) Node. This platform, which now contains over 10 petabytes of data, is called the National Environmental Research Data Interoperability Platform (NERDIP), and is designed to facilitate broad user access, maximise reuse, and enable integration. GA has contributed several hundred terabytes of geophysical data to the NERDIP. Historically, geophysical datasets have been stored in a range of formats, with metadata of varying quality and accessibility, and without standardised vocabularies. This has made it extremely difficult to aggregate original data from multiple surveys (particularly un-gridded geophysics point/line data) into standard formats suited to High Performance Computing (HPC) environments. To address this, it was decided to use the NERDIP-preferred Hierarchical Data Format (HDF) 5, which is a proven, standard, open, self-describing and high-performance format supported by extensive software tools, libraries and data services. The Network Common Data Form (NetCDF) 4 API facilitates the use of data in HDF5, whilst the NetCDF Climate & Forecasting conventions (NetCDF-CF) further constrain NetCDF4/HDF5 data so as to provide greater inherent interoperability. The first geophysical data collection selected for transformation by GA was Airborne ElectroMagnetics (AEM) data which was held in proprietary-format files, with associated ISO 19115 metadata held in a separate relational database. Existing NetCDF-CF metadata profiles were enhanced to cover AEM and other geophysical data types, and work is underway to formalise the new geophysics vocabulary as a proposed extension to the Climate & Forecasting conventions. The richness and flexibility of HDF5's internal indexing mechanisms has allowed lossless restructuring of the AEM data for efficient storage, subsetting and access via either the NetCDF4/HDF5 APIs or Open-source Project for a Network Data Access Protocol (OPeNDAP) data services. This approach not only supports large-scale HPC processing, but also interactive access to a wide range of geophysical data in user-friendly environments such as iPython notebooks and more sophisticated cloud-enabled portals such as the Virtual Geophysics Laboratory (VGL). As multidimensional AEM datasets are relatively complex compared to other geophysical data types, the general approach employed in this project for modernizing AEM data is likely to be applicable to other geophysics data types. When combined with the use of standards-based data services and APIs, a coordinated, systematic modernisation will result in vastly improved accessibility to, and usability of, geophysical data in a wide range of computational environments both within and beyond the geophysics community.
A German Geophysics School Project First steps to bring geophysical topics to schoolclasses
NASA Astrophysics Data System (ADS)
Schneider, S.
2002-12-01
In Germany Geophysics is a science with almost none or a bad reputation. People do not know to distinguish between Geophysics, Geography and Geology. In order to change the public view on Geosciences, a,School Project Geophysics' is going to be created at the Institute of Meteorology and Geophysics, Johann Wolfgang Goethe University, Frankfurt, which will offer geophysical ideas, methodes and scientific results to schoolclasses. After researches like PISA or TIMSS (third international Math and Nature-Science test) new concepts in education will be required. Interdisciplinary tasks are demanded by national and international commissions.\\The,School Project Geophysics' will be created to bring geophysical themes and results of scientific research into schools. One Day- or one Week-Workshops will help to publish geophysical contents in close cooperation with Physics - and Geography - teachers.\\Hands-on experiments (for advanced pupils) like refraction-Seismics or Magnetic measurements will lead students closer to scientific work and will help to establish personal interests in Earthsciences. Working with personally produced datasets will show the basics of inversion theory and point out the difficulties in creating models. Boundaries of data interpretation (the plurality of variables needed) will teach the school children to see scientific and statistic predictions and declarations more criticaly. Animations and Videos will present global examples (for example of volcanoes or Earthquakes) and lead over to regional sites. Excursions to these sites will help to show fieldwork methods and its problems and will convince to take a different look on topography and landscapes.\\All necessary utilities (Animations, Videos, Pictures and foils) will be offered to teachers in an online-data base which will be installed and managed by the project. Teachers and pupils might get easily into contact with Scientists to discuss geoscientific items. Further on extensions to geographic and geologic topics could be additional targets to this project. A poster will show the structure of one examplary workshop. This poster might stimulate to discuss experiences and further ideas.
Living microorganisms change the information (Shannon) content of a geophysical system.
Tang, Fiona H M; Maggi, Federico
2017-06-12
The detection of microbial colonization in geophysical systems is becoming of interest in various disciplines of Earth and planetary sciences, including microbial ecology, biogeochemistry, geomicrobiology, and astrobiology. Microorganisms are often observed to colonize mineral surfaces, modify the reactivity of minerals either through the attachment of their own biomass or the glueing of mineral particles with their mucilaginous metabolites, and alter both the physical and chemical components of a geophysical system. Here, we hypothesise that microorganisms engineer their habitat, causing a substantial change to the information content embedded in geophysical measures (e.g., particle size and space-filling capacity). After proving this hypothesis, we introduce and test a systematic method that exploits this change in information content to detect microbial colonization in geophysical systems. Effectiveness and robustness of this method are tested using a mineral sediment suspension as a model geophysical system; tests are carried out against 105 experiments conducted with different suspension types (i.e., pure mineral and microbially-colonized) subject to different abiotic conditions, including various nutrient and mineral concentrations, and different background entropy production rates. Results reveal that this method can systematically detect microbial colonization with less than 10% error in geophysical systems with low-entropy background production rate.
NASA Astrophysics Data System (ADS)
Day-Lewis, F. D.
2014-12-01
Geophysical imaging (e.g., electrical, radar, seismic) can provide valuable information for the characterization of hydrologic properties and monitoring of hydrologic processes, as evidenced in the rapid growth of literature on the subject. Geophysical imaging has been used for monitoring tracer migration and infiltration, mapping zones of focused groundwater/surface-water exchange, and verifying emplacement of amendments for bioremediation. Despite the enormous potential for extraction of hydrologic information from geophysical images, there also is potential for misinterpretation and over-interpretation. These concerns are particularly relevant when geophysical results are used within quantitative frameworks, e.g., conversion to hydrologic properties through petrophysical relations, geostatistical estimation and simulation conditioned to geophysical inversions, and joint inversion. We review pitfalls to interpretation associated with limited image resolution, spatially variable image resolution, incorrect data weighting, errors in the timing of measurements, temporal smearing resulting from changes during data acquisition, support-volume/scale effects, and incorrect assumptions or approximations involved in modeling geophysical or other jointly inverted data. A series of numerical and field-based examples illustrate these potential problems. Our goal in this talk is to raise awareness of common pitfalls and present strategies for recognizing and avoiding them.
Publications - IC 50 | Alaska Division of Geological & Geophysical Surveys
Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey ic050.pdf (999.0 K) Keywords Aeromagnetic; Aeromagnetic Map; Aeromagnetic Survey; Alaska Peninsula ; Coal; Conductivity Survey; Construction Materials; Copper; Cretaceous; Delta River; Diamonds; Drilling
Application of geophysical methods to agriculture: An overview
USDA-ARS?s Scientific Manuscript database
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...
USDA-ARS?s Scientific Manuscript database
Near-surface geophysical methods have become have become important tools for agriculture. Geophysics employed for agriculture tends to be heavily focused on a 2 m zone directly beneath the ground surface, which includes the crop root zone and all, or at least most, of the soil profile. Resistivity...
Evaluation of geophysical methods and geophysical contractors on four projects in Kentucky.
DOT National Transportation Integrated Search
2007-03-01
his report details four geophysical testing projects that were conducted in Kentucky for the Kentucky Transportation Cabinet. The four projects were as follows: KY 101, Edmonson and Warren Counties, US 31-W, Elizabethtown Bypass, Hardin County, KY 61...
Fiber optic geophysical sensors
Homuth, E.F.
1991-03-19
A fiber optic geophysical sensor is described in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects. 2 figures.
NASA Astrophysics Data System (ADS)
Gottschalk, Ian P.; Hermans, Thomas; Knight, Rosemary; Caers, Jef; Cameron, David A.; Regnery, Julia; McCray, John E.
2017-12-01
Geophysical data have proven to be very useful for lithological characterization. However, quantitatively integrating the information gained from acquiring geophysical data generally requires colocated lithological and geophysical data for constructing a rock-physics relationship. In this contribution, the issue of integrating noncolocated geophysical and lithological data is addressed, and the results are applied to simulate groundwater flow in a heterogeneous aquifer in the Prairie Waters Project North Campus aquifer recharge site, Colorado. Two methods of constructing a rock-physics transform between electrical resistivity tomography (ERT) data and lithology measurements are assessed. In the first approach, a maximum likelihood estimation (MLE) is used to fit a bimodal lognormal distribution to horizontal crosssections of the ERT resistivity histogram. In the second approach, a spatial bootstrap is applied to approximate the rock-physics relationship. The rock-physics transforms provide soft data for multiple point statistics (MPS) simulations. Subsurface models are used to run groundwater flow and tracer test simulations. Each model's uncalibrated, predicted breakthrough time is evaluated based on its agreement with measured subsurface travel time values from infiltration basins to selected groundwater recovery wells. We find that incorporating geophysical information into uncalibrated flow models reduces the difference with observed values, as compared to flow models without geophysical information incorporated. The integration of geophysical data also narrows the variance of predicted tracer breakthrough times substantially. Accuracy is highest and variance is lowest in breakthrough predictions generated by the MLE-based rock-physics transform. Calibrating the ensemble of geophysically constrained models would help produce a suite of realistic flow models for predictive purposes at the site. We find that the success of breakthrough predictions is highly sensitive to the definition of the rock-physics transform; it is therefore important to model this transfer function accurately.
Notes on the history of geophysics in the Ottoman Empire
NASA Astrophysics Data System (ADS)
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.
Development of Geophysical Ideas and Institutions in Ottoman Empire
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Mizukami, N.; Clark, M. P.; Newman, A. J.; Wood, A.; Gutmann, E. D.
2017-12-01
Estimating spatially distributed model parameters is a grand challenge for large domain hydrologic modeling, especially in the context of hydrologic model applications such as streamflow forecasting. Multi-scale Parameter Regionalization (MPR) is a promising technique that accounts for the effects of fine-scale geophysical attributes (e.g., soil texture, land cover, topography, climate) on model parameters and nonlinear scaling effects on model parameters. MPR computes model parameters with transfer functions (TFs) that relate geophysical attributes to model parameters at the native input data resolution and then scales them using scaling functions to the spatial resolution of the model implementation. One of the biggest challenges in the use of MPR is identification of TFs for each model parameter: both functional forms and geophysical predictors. TFs used to estimate the parameters of hydrologic models typically rely on previous studies or were derived in an ad-hoc, heuristic manner, potentially not utilizing maximum information content contained in the geophysical attributes for optimal parameter identification. Thus, it is necessary to first uncover relationships among geophysical attributes, model parameters, and hydrologic processes (i.e., hydrologic signatures) to obtain insight into which and to what extent geophysical attributes are related to model parameters. We perform multivariate statistical analysis on a large-sample catchment data set including various geophysical attributes as well as constrained VIC model parameters at 671 unimpaired basins over the CONUS. We first calibrate VIC model at each catchment to obtain constrained parameter sets. Additionally, parameter sets sampled during the calibration process are used for sensitivity analysis using various hydrologic signatures as objectives to understand the relationships among geophysical attributes, parameters, and hydrologic processes.
Some case studies of geophysical exploration of archaeological sites in Yugoslavia
NASA Astrophysics Data System (ADS)
Komatina, Snezana; Timotijevic, Zoran
1999-03-01
One of the youngest branches of environmental geophysics application is the preservation of national heritage. Numerous digital techniques developed for exploration directed to urban planning can also be applied to investigations of historic buildings. In identifying near-surface layers containing objects of previous civilizations, various sophisticated geophysical methods are used. In the paper, application of geophysics in quantification of possible problems necessary to be carried out in order to get an archaeological map of some locality is discussed [Komatina, S., 1996]. Sophisticated geophysical methods in the preservation of national heritage. Proc. of Int. Conf. Architecture and Urbanism at the turn of the Millenium, Beograd, pp. 39-44. Finally, several examples of archaeogeophysical exploration at Divostin, Bedem and Kalenic monastery localities (Serbia, Yugoslavia) are presented.
Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications
Grauch, V.J.; Sawyer, David A.; Fridrich, Chris J.; Hudson, Mark R.
1999-01-01
Gravity and magnetic data, when integrated with other geophysical, geological, and rock-property data, provide a regional framework to view the subsurface geology in the southwestern Nevada volcanic field. The region has been loosely divided into six domains based on structural style and overall geophysical character. For each domain, the subsurface tectonic and magmatic features that have been inferred or interpreted from previous geophysical work has been reviewed. Where possible, abrupt changes in geophysical fields as evidence for potential structural lithologic control on ground-water flow has been noted. Inferred lithology is used to suggest associated hydrogeologic units in the subsurface. The resulting framework provides a basis for investigators to develop hypotheses from regional ground-water pathways where no drill-hole information exists.
High resolution land surface geophysical parameters estimation from ALOS PALSAR data
USDA-ARS?s Scientific Manuscript database
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...
Solar flare emissions and geophysical disturbances
NASA Technical Reports Server (NTRS)
Sakurai, K.
1973-01-01
Various geophysical phenomena are produced by both wave and particle emissions from solar flares. Using the observed data for these emissions, a review is given on the nature of solar flares and their development. Geophysical phenomena are discussed by referring to the results for solar flare phenomena.
Publications - AR 2005 | Alaska Division of Geological & Geophysical
Publications Geologic Materials Center General Information Inventory Monthly Report Hours and Location Policy Report Authors: DGGS Staff Publication Date: Feb 2006 Publisher: Alaska Division of Geological & Geological & Geophysical Surveys Annual Report: Alaska Division of Geological & Geophysical Surveys
Publications - AR 2009 | Alaska Division of Geological & Geophysical
Publications Geologic Materials Center General Information Inventory Monthly Report Hours and Location Policy Report Authors: DGGS Staff Publication Date: Jan 2010 Publisher: Alaska Division of Geological & Geological & Geophysical Surveys Annual Report: Alaska Division of Geological & Geophysical Surveys
Introduction to the JEEG Agricultural Geophysics special issue
USDA-ARS?s Scientific Manuscript database
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...
An Introduction to Using Surface Geophysics to Characterize Sand and Gravel Deposits
Lucius, Jeffrey E.; Langer, William H.; Ellefsen, Karl J.
2006-01-01
This report is an introduction to surface geophysical techniques that aggregate producers can use to characterize known deposits of sand and gravel. Five well-established and well-tested geophysical methods are presented: seismic refraction and reflection, resistivity, ground penetrating radar, time-domain electromagnetism, and frequency-domain electromagnetism. Depending on site conditions and the selected method(s), geophysical surveys can provide information concerning aerial extent and thickness of the deposit, thickness of overburden, depth to the water table, critical geologic contacts, and location and correlation of geologic features. In addition, geophysical surveys can be conducted prior to intensive drilling to help locate auger or drill holes, reduce the number of drill holes required, calculate stripping ratios to help manage mining costs, and provide continuity between sampling sites to upgrade the confidence of reserve calculations from probable reserves to proved reserves. Perhaps the greatest value of geophysics to aggregate producers may be the speed of data acquisition, reduced overall costs, and improved subsurface characterization.
An Introduction to Using Surface Geophysics to Characterize Sand and Gravel Deposits
Lucius, Jeffrey E.; Langer, William H.; Ellefsen, Karl J.
2007-01-01
This report is an introduction to surface geophysical techniques that aggregate producers can use to characterize known deposits of sand and gravel. Five well-established and well-tested geophysical methods are presented: seismic refraction and reflection, resistivity, ground penetrating radar, time-domain electromagnetism, and frequency-domain electromagnetism. Depending on site conditions and the selected method(s), geophysical surveys can provide information concerning areal extent and thickness of the deposit, thickness of overburden, depth to the water table, critical geologic contacts, and location and correlation of geologic features. In addition, geophysical surveys can be conducted prior to intensive drilling to help locate auger or drill holes, reduce the number of drill holes required, calculate stripping ratios to help manage mining costs, and provide continuity between sampling sites to upgrade the confidence of reserve calculations from probable reserves to proved reserves. Perhaps the greatest value of geophysics to aggregate producers may be the speed of data acquisition, reduced overall costs, and improved subsurface characterization.
An Integral, Multidisciplinary and Global Geophysical Field Experience for Undergraduates
NASA Astrophysics Data System (ADS)
Vázquez, O.; Carrillo, D. J.; Pérez-Campos, X.
2007-05-01
The udergraduate program of Geophysical Engineering at the School of Engineering, of the Univesidad Nacional Autónoma de México (UNAM), went through an update process that concluded in 2006. As part of the program, the student takes three geophysical prospecting courses (gravity and magnetics, electric, electromagnetics, and seismic methods). The older program required a three-week field experience for each course in order to gradute. The new program considers only one extended field experience. This work stresses the importance of international academic exchange, where undergraduate students could participate, such as the Summer of Applied Geophysical Experience (SAGE), and interaction with research programs, such as the MesoAmerican Subduction Experiment (MASE). Also, we propose a scheeme for this activity based on those examples; both of them have in common real geophysical problems, from which students could benefit. Our proposal covers academic and logistic aspects to be taken into account, enhancing the relevance of interaction between other academic institutions, industry, and UNAM, in order to obtain a broader view of geophysics.
Publications - GPR 2011-4 | Alaska Division of Geological & Geophysical
Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey content DGGS GPR 2011-4 Publication Details Title: Iditarod survey area: Airborne magnetic and ., Fugro Airborne Surveys Corp., and Fugro GeoServices, Inc., 2015, Iditarod survey area: Airborne magnetic
About Us | Alaska Division of Geological & Geophysical Surveys
Division of Geological & Geophysical Surveys (DGGS) 3354 College Road, Fairbanks, AK 99709 Phone: (907 Division also administers the 11-member Alaska Seismic Hazards Safety Commission. Accomplishments The . Department of Natural Resources, Division of Geological & Geophysical Surveys (DGGS) 3354 College Road
Geophysics: The Earth in Space. A Guide for High School Students.
ERIC Educational Resources Information Center
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…
Publications - GMC 85 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ) well Authors: Unknown Publication Date: 1988 Publisher: Alaska Division of Geological & Geophysical (Orion) well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center Data
Publications - GMC 89 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ) well Authors: Unknown Publication Date: 1988 Publisher: Alaska Division of Geological & Geophysical (Mars) well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center Data
Staff - April M. Woolery | Alaska Division of Geological & Geophysical
SurveysA> Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey
Publications - AR 2010-D | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2010-D main content DGGS AR 2010-D Publication Details Title: Volcanology FY11 project descriptions Authors: Nye, C.J
Publications - AR 2011-E | Alaska Division of Geological & Geophysical
, Geologic Communications FY12 project descriptions, in DGGS Staff, Alaska Division of Geological & Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2011-E main
Publications - GMC 263 | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications GMC 263 main content DGGS GMC 263 Publication Details Title: Map location and geological logs of core for 1994 diamond drill
Publications - GMC 1 | Alaska Division of Geological & Geophysical Surveys
State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications GMC 1 main content Itkillik #1 well Authors: Amerada Hess Corporation, and Chemical and Geological Laboratories of Alaska
Publications - AR 2011-D | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2011-D main content DGGS AR 2011-D Publication Details Title: Volcanology FY12 project descriptions Authors: Nye, C.J
Publications - GPR 2014-4 | Alaska Division of Geological & Geophysical
Geologic Mapping Advisory Board STATEMAP Publications Geophysics Program Information Geophysical Survey content DGGS GPR 2014-4 Publication Details Title: Farewell and Middle Styx survey areas: Project report , Inc., 2015, Farewell and Middle Styx survey areas: Project report, interpretation maps, EM anomalies
Solar Wind Monitor--A School Geophysics Project
ERIC Educational Resources Information Center
Robinson, Ian
2018-01-01
Described is an established geophysics project to construct a solar wind monitor based on a nT resolution fluxgate magnetometer. Low-cost and appropriate from school to university level it incorporates elements of astrophysics, geophysics, electronics, programming, computer networking and signal processing. The system monitors the earth's field in…
Geophysical Surveys for Locating Buried Utilities, Lake Pontchartrain Levees, New Orleans
2014-06-01
4 Figure 3. GPR concepts...this study. Electromagnetic (EM) induction, magnetic, and ground penetrating radar ( GPR ) geophysical methods were evaluated to determine which...surveys GPR is a ground-based geophysical instrument that transmits high- frequency EM pulses into the subsurface. The GPR system consists of a
The purpose of the work was to determine the capability of various geophysical methods to detect PCE in the subsurface. Measurements were made with ten different geophysical techniques before, during, and after the PCE injection. This approach provided a clear identification of a...
Publications - PIR 2015-3 | Alaska Division of Geological & Geophysical
Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications PIR 2015-3 main content DGGS PIR 2015-3 Publication Details Title: Overview of 2014 energy-focused studies in Susitna of Geological & Geophysical Surveys Preliminary Interpretive Report 2015-3, 34 p. http://doi.org
30 CFR 280.51 - What types of geophysical data and information must I submit to MMS?
Code of Federal Regulations, 2010 CFR
2010-07-01
..., shallow and deep subbottom profiles, bathymetry, sidescan sonar, gravity and magnetic surveys, and special... and of a quality suitable for processing; (c) Processed geophysical information derived from seismic... interpretive evaluation, reflecting state-of-the-art processing techniques; and (d) Other geophysical data...
Remote sensing-a geophysical perspective.
Watson, K.
1985-01-01
In this review of developments in the field of remote sensing from a geophysical perspective, the subject is limited to the electromagnetic spectrum from 0.4 mu m to 25cm. Three broad energy categories are covered: solar reflected, thermal infrared, and microwave.-from Authorremote sensing electromagnetic spectrum solar reflected thermal infrared microwave geophysics
Mobile geophysics for searching and exploration of Domanic hydrocarbon deposits
NASA Astrophysics Data System (ADS)
Borovsky, M. Ya; Uspensky, B. V.; Valeeva, S. E.; Borisov, A. S.
2018-05-01
There are noted features of shale hydrocarbons occurrence. It is shown the role of geophysical prospecting in the geological prospecting process for non-traditional sources of hydrocarbon. There are considered the possibilities of non-seismic methods for forecasting, prospecting, exploration and preparation of Domanikovian hydrocarbons accumulations for exploration. It is emphasized the need for geophysical studies of tectonic disturbances. Modern aerogeophysical instrumentation and methodological support allows to combine high-precision magneto-prospecting with gravimetric and gamma spectrometry. This combination of geophysical methods contributes to the diagnosis of active and latent faults.
NASA Astrophysics Data System (ADS)
Gordeev, V. F.; Malyshkov, S. Yu.; Botygin, I. A.; Sherstnev, V. S.; Sherstneva, A. I.
2017-11-01
The general trend of modern ecological geophysics is changing priorities towards rapid assessment, management and prediction of ecological and engineering soil stability as well as developing brand new geophysical technologies. The article describes researches conducted by using multi-canal geophysical logger MGR-01 (developed by IMCES SB RAS), which allows to measure flux density of very low-frequency electromagnetic radiation. It is shown that natural pulsed electromagnetic fields of the earthen lithosphere can be a source of new information on Earth's crust and processes in it, including earthquakes. The device is intended for logging electromagnetic processes in Earth's crust, geophysical exploration, finding structural and lithological inhomogeneities, monitoring the geodynamic movement of Earth's crust, express assessment of seismic hazards. The data is gathered automatically from observation point network in Siberia
Application of surface geophysics to ground-water investigations
Zohdy, Adel A.R.; Eaton, Gordon P.; Mabey, Don R.
1974-01-01
This manual reviews the standard methods of surface geophysics applicable to ground-water investigations. It covers electrical methods, seismic and gravity methods, and magnetic methods. The general physical principles underlying each method and its capabilities and limitations are described. Possibilities for non-uniqueness of interpretation of geophysical results are noted. Examples of actual use of the methods are given to illustrate applications and interpretation in selected geohydrologic environments. The objective of the manual is to provide the hydrogeologist with a sufficient understanding of the capabilities, imitations, and relative cost of geophysical methods to make sound decisions as to when to use of these methods is desirable. The manual also provides enough information for the hydrogeologist to work with a geophysicist in designing geophysical surveys that differentiate significant hydrogeologic changes.
Results of airborne geophysical surveys in the Weser-Elbe area in Northern Germany
NASA Astrophysics Data System (ADS)
Meyer, U.; Siemon, B.; Steuer, A.; Ibs-von Seht, M.; Voss, W.; Miensopust, M. P.; Wiederhold, H.
2012-12-01
Airborne geophysical surveys were carried out by the German Federal Institute for Geosciences and Natural Resources (BGR) in Northern Germany close to the estuaries of the Weser and Elbe rivers from 2000 to 2010. Two of the six helicopter-borne surveys were conducted in cooperation with the Leibniz Institute for Applied Geophysics (LIAG). The common aim was the acquisition of a reference data set for monitoring climate or man-made induced changes of the saltwater/freshwater interface at the German North Sea coast and to build up a data base containing all airborne geophysical data sets. Airborne frequency-domain electromagnetic, magnetic, and radiometric data were collected simultaneously with the helicopter-borne geophysical system operated at BGR. The airborne geophysical results show both geological and hydrogeological structures down to about 100 m depth. The electromagnetic results reveal several hydrogeological important features such as the distribution of sandy or clayey sediments, the extension of saltwater intrusion, and buried valleys. These results are supported by magnetic and radiometric data indicating lateral changes of weakly magnetized sediments or mineral compositions of the top soil. The airborne geophysical data sets provide serve as base-line data for a variety of applications and particularly for groundwater modeling and monitoring.
Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range
NASA Astrophysics Data System (ADS)
Koppenjan, S.,; Martinez, M.
The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteria for the development of geophysical technologies and techniques. The US DOE's Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a 'chirped' FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site.
Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koppenjan, S,; Martinez, M.
1994-06-01
The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteriamore » for the development of geophysical technologies and techniques. The US DOE`s Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a ``chirped`` FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site.« less
NASA Astrophysics Data System (ADS)
Reeves, P.; McKenna, S. A.; Takeuchi, S.; Saegusa, H.
2003-12-01
In situ measurements of hydraulic conductivity in fractured rocks are expensive to acquire. Borehole geophysical measurements are relatively inexpensive to acquire but do not provide direct information on hydraulic conductivity. These geophysical measurements quantify properties of the rock that influence the hydraulic conductivity and it may be possible to employ a non-linear combination of these measurements to estimate hydraulic conductivity. Geophysical measurements collected in fractured granite at the Shobasama site in central Japan were used as the input to a feed-forward neural network. A simple genetic algorithm was used to simultaneously evolve the architecture and parameters of the neural network as well as determine an optimal subset of geophysical measurements for the prediction of hydraulic conductivity. The initial estimation procedure focused on predicting the class of the hydraulic conductivity, high, medium or low, from the geophysical measurements. This estimation was done while using the genetic algorithm to simultaneously determine the most important geophysical logs and optimize the architecture of the neural network. Results show that certain geophysical logs provide more information than others- most notably the short-normal resistivity, micro-resistivity, porosity and sonic logs provided the most information on hydraulic conductivity. The neural network produced excellent training results with accuracy of 90 percent or greater, but was unable to produce accurate predictions of the hydraulic conductivity class In the second phase of calculations, the selection of geophysical measurements is limited to only those that provide significant information. Additionally, this second phase predicts transmissivity instead of hydraulic conductivity in order to account for the differences in the length of the hydraulic test zones. Resulting predictions of transmissivity exhibit conditional bias with maximum prediction errors of three orders of magnitude occurring at the extreme measurement values. Results of these simulations indicate that the most informative geophysical measurements for the prediction of transmissivity are depth and sonic velocity. The long normal resistivity and self potential geophysical measurements are moderately informative. In addition, it was found that porosity and crack counts (clear, open, or hairline) do not inform predictions of transmissivity. This work was funded by the Japan Nuclear Cycle Development Institute. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94-AL-85000
Field Geophysics at SAGE: Strategies for Effective Education
NASA Astrophysics Data System (ADS)
Braile, L. W.; Baldridge, W. S.; Jiracek, G. R.; Biehler, S.; Ferguson, J. F.; Pellerin, L.; McPhee, D. K.; Bedrosian, P. A.; Snelson, C. M.; Hasterok, D. P.
2011-12-01
SAGE (Summer of Applied Geophysical Experience) is a unique program of education and research in geophysical field methods for undergraduate and graduate students from any university and for professionals. The core program is held for 4 weeks each summer in New Mexico and for an additional week in the following academic year in San Diego for U.S. undergraduates supported by the NSF Research Experience for Undergraduates (REU) program. Since SAGE was initiated in 1983, 730 students have participated in the program. NSF REU funding for SAGE began in 1990 and 319 REU students have completed SAGE through 2011. The primary objectives of SAGE are to teach the major geophysical exploration methods (seismic, gravity, magnetics, electromagnetics); apply these methods to the solution of specific problems (environmental, archaeological, hydrologic, geologic structure and stratigraphy); gain experience in processing, modeling and interpretation of geophysical data; and integrate the geophysical models and interpretations with geology. Additional objectives of SAGE include conducting research on the Rio Grande rift of northern New Mexico, and providing information on geophysics careers and professional development experiences to SAGE participants. Successful education, field and research strategies that we have implemented over the years include: 1. learn by doing; 2. mix lecture/discussion, field work, data processing and analysis, modeling and interpretation, and presentation of results; 3. a two-tier team approach - method/technique oriented teams and interpretation/integration teams (where each team includes persons representing different methods), provides focus, in-depth study, opportunity for innovation, and promotes teamwork and a multi-disciplinary approach; 4. emphasis on presentations/reports - each team (and all team members) make presentation, each student completes a written report; 5. experiment design discussion - students help design field program and consider issues - safety, constraints, data quality/quantity, research objective, educational experience, survey parameters, why multidisciplinary?, etc.; 6. knowledge of multiple geophysical field methods (each student works with all methods); 7. information on geophysics careers and networking provided by industry visitors; 8. measures of success of the program include high rate of continuation to graduate school and careers in geophysics, support and feedback from industry participants and visitors, student evaluations at end of program, presentations at professional meetings, publications, and faculty evaluation of student work.
Publications - AR 2010 | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical DGGS AR 2010 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual Report Authors: DGGS Staff Publication Date: Jan 2011 Publisher: Alaska Division of Geological &
Publications - RDF 2015-8 | Alaska Division of Geological & Geophysical
from the Tonsina area, Valdez Quadrangle, Alaska: Alaska Division of Geological & Geophysical Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical
Publications - GMC 55 | Alaska Division of Geological & Geophysical Surveys
Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications GMC 55 main content DGGS GMC 55 Publication Details Title: Geochemical report TOC/rock-eval pyrolysis results for Louisiana ; Geophysical Surveys Geologic Materials Center Data Report 55, 18 p. http://doi.org/10.14509/19198 Publication
36 CFR 1256.62 - Geological and geophysical information relating to wells.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical... MATERIALS General Restrictions § 1256.62 Geological and geophysical information relating to wells. (a) In accordance with 5 U.S.C. 552(b)(9), NARA may withhold information in records that relates to geological and...
Code of Federal Regulations, 2010 CFR
2010-07-01
... information, and interpreted geophysical information including, but not limited to, shallow and deep subbottom...) You must notify the Regional Director, in writing, when you complete the initial processing and interpretation of any geophysical data and information. Initial processing is the stage of processing where the...
Automated lithology prediction from PGNAA and other geophysical logs.
Borsaru, M; Zhou, B; Aizawa, T; Karashima, H; Hashimoto, T
2006-02-01
Different methods of lithology predictions from geophysical data have been developed in the last 15 years. The geophysical logs used for predicting lithology are the conventional logs: sonic, neutron-neutron, gamma (total natural-gamma) and density (backscattered gamma-gamma). The prompt gamma neutron activation analysis (PGNAA) is another established geophysical logging technique for in situ element analysis of rocks in boreholes. The work described in this paper was carried out to investigate the application of PGNAA to the lithology interpretation. The data interpretation was conducted using the automatic interpretation program LogTrans based on statistical analysis. Limited test suggests that PGNAA logging data can be used to predict the lithology. A success rate of 73% for lithology prediction was achieved from PGNAA logging data only. It can also be used in conjunction with the conventional geophysical logs to enhance the lithology prediction.
Notes on interpretation of geophysical data over areas of mineralization in Afghanistan
Drenth, Benjamin J.
2011-01-01
Afghanistan has the potential to contain substantial metallic mineral resources. Although valuable mineral deposits have been identified, much of the country's potential remains unknown. Geophysical surveys, particularly those conducted from airborne platforms, are a well-accepted and cost-effective method for obtaining information on the geological setting of a given area. This report summarizes interpretive findings from various geophysical surveys over selected mineral targets in Afghanistan, highlighting what existing data tell us. These interpretations are mainly qualitative in nature, because of the low resolution of available geophysical data. Geophysical data and simple interpretations are included for these six areas and deposit types: (1) Aynak: Sedimentary-hosted copper; (2) Zarkashan: Porphyry copper; (3) Kundalan: Porphyry copper; (4) Dusar Shaida: Volcanic-hosted massive sulphide; (5) Khanneshin: Carbonatite-hosted rare earth element; and (6) Chagai Hills: Porphyry copper.
A review of the regional geophysics of the Arizona Transition Zone
Hendricks, J.D.; Plescia, J.B.
1991-01-01
A review of existing geophysical information and new data presented in this special section indicate that major changes in crustal properties between the Basin and Range and Colorado Plateau occur in, or directly adjacent to, the region defined as the Arizona Transition Zone. Although this region was designated on a physiographic basis, studies indicate that it is also the geophysical transition between adjoining provinces. A relatively shallow asthenosphere beneath the Basin and Range and Transition Zone contrasted with a thick lithosphere beneath the Colorado Plateau would be one explanation that would satisfy these geophysical observations. -from Authors
Lane, John W.; Day-Lewis, Frederick D.; Johnson, Carole D.; Joesten, Peter K.; Kochiss, Christopher S.
2007-01-01
Based on the geophysical data, conceptual models of the distributions of emulsified vegetable oil and ground water with altered chemistry were developed. The field data indicate that, in several cases, the plume of ground water with altered chemistry would not be detected by direct chemical sampling given the construction of monitoring wells; hence the geophysical data provide valuable site-specific insights for the interpretation of water samples and monitoring of biostimulation projects. Application of geophysical methods to data from the ACP demonstrated the utility of radar for monitoring biostimulation injections.
Publications - NL 2002-1 | Alaska Division of Geological & Geophysical
Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical 2002 Publisher: Alaska Division of Geological & Geophysical Surveys Ordering Info: Download below Reference DGGS Staff, and Werdon, M.B., 2002, Alaska GeoSurvey News - Geologic Investigations in the Salcha
Report on Operations of the Air Force Geophysics Laboratory Infrared Array Spectrometer
1993-01-25
AIR FORCE GEOPHYSICS LABORATORY INFRARED ARRAY... LABORATORY Directorate of Geophysics AIR FORCE MATERIEL COMMAND HANSCOM AIR FORCE BASE, MA 01731-3010 93-27655IEEE|EIIE1ENI This technical report has...ACKNOWLEDGMENT We are grateful to the Air Force Office of Scientific Research , especially Henry Radowski. for their financial corn- mitment to this project.
Ezra Zemach
2010-01-01
Multiple data sets converge on a geologic structural model for Glass Buttes, Oregon geothermal prospect, Patrick Walsh, Brigette Martini, Chet Lide, Darrick Boschmann, John DIlles, Andrew Meigs, 2010 Ormat Nevada, Zonge Geophysical, Oregon State University American Geophysical Union, Poster Session
Code of Federal Regulations, 2010 CFR
2010-07-01
... Geophysical (G&G) prospecting or scientific research? 280.20 Section 280.20 Mineral Resources MINERALS... What must I not do in conducting Geological and Geophysical (G&G) prospecting or scientific research? While conducting G&G prospecting or scientific research activities under a permit or notice, you must...
30 CFR 550.244 - What geological and geophysical (G&G) information must accompany the DPP or DOCD?
Code of Federal Regulations, 2014 CFR
2014-07-01
... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What geological and geophysical (G&G... Operations Coordination Documents (docd) § 550.244 What geological and geophysical (G&G) information must accompany the DPP or DOCD? The following G&G information must accompany your DPP or DOCD: (a) Geological...
30 CFR 550.244 - What geological and geophysical (G&G) information must accompany the DPP or DOCD?
Code of Federal Regulations, 2013 CFR
2013-07-01
... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What geological and geophysical (G&G... Operations Coordination Documents (docd) § 550.244 What geological and geophysical (G&G) information must accompany the DPP or DOCD? The following G&G information must accompany your DPP or DOCD: (a) Geological...
30 CFR 550.244 - What geological and geophysical (G&G) information must accompany the DPP or DOCD?
Code of Federal Regulations, 2012 CFR
2012-07-01
... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What geological and geophysical (G&G... Operations Coordination Documents (docd) § 550.244 What geological and geophysical (G&G) information must accompany the DPP or DOCD? The following G&G information must accompany your DPP or DOCD: (a) Geological...
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When do I notify MMS that geophysical data and... MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE PROSPECTING FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR ON THE OUTER CONTINENTAL SHELF Data Requirements Geophysical Data and Information...
Reynolds, Richard J.; Anderson, J. Alton; Williams, John H.
2015-01-01
The geophysical logs and their analyses are available for display and download from the U.S. Geological Survey, New York Water Science Center, online geophysical log archive (http://ny.water.usgs.gov/maps/geologs/) in LAS (Log ASCII Standard), PDF, and WellCad formats.
Geophysics Education and Research in India and Role of International Collaboration
NASA Astrophysics Data System (ADS)
Rajaram, M.
2007-12-01
Some possible avenues for strengthening Geophysics education in India will be examined and possible ways of making the system more dynamic and responsive to the needs will be suggested. Out of the few hundred Universities in India under the University Grants Commission, only around a dozen offer post-graduate degree courses in Geophysics. Over the last decade the demand for Geophysicists has increased tremendously, with the country having opened its gates to foreign companies to invest in India; as a consequence, Geophysics is soon becoming the favored subject for the best students undertaking Post Graduate Courses in Science. Geophysics as a subject is independent of national and international borders and it would prove very useful for students to have international exposure. We have in India, the example of the internationally renowned, Indian Institute of Technology. These Institutes were started with foreign collaboration that included Professors from the collaborating countries taking up selected under-graduate courses. For Geophysics courses it would prove very helpful if students could spend several months at a participating foreign Institution and undertake a project there, as a part of the Geophysics curriculum. India provides the unique settings of having rock types from the Archean to the Present and should attract Geophysicists globally. On an exchange basis foreign students could visit India for their project work. National Science Departments / Universities / Scientific Societies could help provide financial assistance to facilitate this exchange; existing bilateral cooperation could also be used to finance geophysics education. Also oil companies could sponsor geophysics students. Further, due to the high costs of Geophysics Journal, very few Indian Universities are able to subscribe to them. On the Research Arena, there are several areas that by their very nature invoke global interest; for example Research on Antarctica. Currently several countries including India are undertaking Research in Antarctica. International Geophysical Year was a critical point in the development of Antarctic research and expeditions, and through participation by 80,000 international scientists, led to a major expansion in scientific activity focused on Antarctica. Antarctica plays a key role in the Gondwana break up and a Chapman Conference could bring together not only Scientists from the countries that were part of Gondwanaland but all countries that have a stake in Antarctica so as to exchange information using available data and compliment studies by collaborations. The paper will discuss possible avenues of International collaboration to increase productivity in Research and active involvement of students at the grass root levels.
Methodological Developments in Geophysical Assimilation Modeling
NASA Astrophysics Data System (ADS)
Christakos, George
2005-06-01
This work presents recent methodological developments in geophysical assimilation research. We revisit the meaning of the term "solution" of a mathematical model representing a geophysical system, and we examine its operational formulations. We argue that an assimilation solution based on epistemic cognition (which assumes that the model describes incomplete knowledge about nature and focuses on conceptual mechanisms of scientific thinking) could lead to more realistic representations of the geophysical situation than a conventional ontologic assimilation solution (which assumes that the model describes nature as is and focuses on form manipulations). Conceptually, the two approaches are fundamentally different. Unlike the reasoning structure of conventional assimilation modeling that is based mainly on ad hoc technical schemes, the epistemic cognition approach is based on teleologic criteria and stochastic adaptation principles. In this way some key ideas are introduced that could open new areas of geophysical assimilation to detailed understanding in an integrated manner. A knowledge synthesis framework can provide the rational means for assimilating a variety of knowledge bases (general and site specific) that are relevant to the geophysical system of interest. Epistemic cognition-based assimilation techniques can produce a realistic representation of the geophysical system, provide a rigorous assessment of the uncertainty sources, and generate informative predictions across space-time. The mathematics of epistemic assimilation involves a powerful and versatile spatiotemporal random field theory that imposes no restriction on the shape of the probability distributions or the form of the predictors (non-Gaussian distributions, multiple-point statistics, and nonlinear models are automatically incorporated) and accounts rigorously for the uncertainty features of the geophysical system. In the epistemic cognition context the assimilation concept may be used to investigate critical issues related to knowledge reliability, such as uncertainty due to model structure error (conceptual uncertainty).
PREFACE: Padjadjaran Earth Dialogues: International Symposium on Geophysical Issues, PEDISGI
NASA Astrophysics Data System (ADS)
Rosandi, Y.; Urbassek, H. M.; Yamanaka, H.
2016-01-01
This issue of IOP Conference Series: Earth and Environmental Science contains selected papers presented at the Padjadjaran Earth Dialogues: International Symposium on Geophysical Issues, PEDISGI. The meeting was held from June 8 to 10, 2015, at the Bale-Sawala of Universitas Padjadjaran in Jatinangor, Indonesia. The PEDISGI is a symposium to accommodate communication between researchers, in particular geophysicists and related scientists, and to enable sharing of knowledge and research findings concerning local and global geophysical issues. The symposium was attended by 126 participants and 64 contributors from Indonesian universities and the neighbouring countries in four categories, viz. Theoretical and Computational Geophysics, Environmental Geophysics, Geophysical Explorations, and Geophysical Instrumentations and Methods. The symposium was accompanied by a dialog, discussing a chosen topic regarding environmental and geological problems of relevance for the Indonesian archipelago and the surrounding regions. For this first event the topic was ''The formation of Bandung-Basin between myths and facts: Exemplary cultural, geological and geophysical study on the evolution of the earth surface'', presented by invited speakers and local experts. This activity was aimed at extending our knowledge on this particular subject, which may have global impact. This topic was augmented by theoretical background lectures on the earth's surface formation, presented by the invited speakers of the symposium. The meeting would not have been successful without the assistance of the local organizing committee. We want to specially thank Irwan A. Dharmawan for managing the programme, Anggie Susilawati and Mia U. Hasanah for the conference administration, and Dini Fitriani for financial management. We also thank the National Geographic Indonesia for its support via the Business to Business Collaboration Program. The conference photograph can be viewed in the PDF.
Geophysical Summer Field Camp: Answering questions about the subsurface for the local community
NASA Astrophysics Data System (ADS)
van Wijk, K.; Batzle, M.; Liberty, L.; Raynolds, R.
2008-12-01
Summer Geophysics Field Camp is part of the core requirement for undergraduate Geophysics majors at Boise State University (CSM), as well as at Colorado School of Mines (CSM). We have found it to be most effectively taught when the target of the camp involves answering questions, which impact society. For example, currently the CSM/BSU geophysics summer camp focuses on ground water resources and geothermal potential in the Upper Arkansas River Basin, a part of the Rio Grande Rift system in Chaffee County, Colorado. A prime goal is to train students how to combine diverse sources of information into a unified interpretation: Students examine lithologies and structures on the periphery of the basin. Cross sections are constructed to predict the geophysical signature. Geophysical tools then are used to ascertain the gross structure and examine subsurface conditions in greater detail. These tools include surveying, regional gravity, deep and shallow seismic surveys, magnetics, DC resistivity, Ground Penetrating Radar, electromagnetics, hydrochemistry, and karaoke. While BSU and CSM own a considerable amount of geophysical hardware, our field camps are only possible because of extensive support by corporations and governmental agencies. In addition, the Society of Exploration Geohysics (SEG) Foundation provides financial support, Chaffee County assists with housing costs, and local land owners provide open access. In turn, the field camp results aid the community of Chaffee County in assessing their water resources for long term growth planning, as well as understanding the geothermal potential for hydroelectric power generation. BSU is currently exploring with the SEG Foundation under the Geophysicists Without Borders program to apply this model of combined education and social outreach in the form a geophysics camp for Southeast Asia, where we propose to study geohazards,geoarcheology and groundwater issues.
The geology and geophysics of the Oslo rift
NASA Technical Reports Server (NTRS)
Ruder, M. E.
1981-01-01
The regional geology and geophysical characteristics of the Oslo graben are reviewed. The graben is part of a Permian age failed continental rift. Alkali olivine, tholefitic, and monzonitic intrusives as well as basaltic lavas outline the extent of the graben. Geophysical evidence indicates that rifting activity covered a much greater area in Skagerrak Sea as well as the Paleozoic time, possibly including the northern Skagerrak Sea as well as the Oslo graben itself. Much of the surficial geologic characteristics in the southern part of the rift have since been eroded or covered by sedimentation. Geophysical data reveal a gravity maximum along the strike of the Oslo graben, local emplacements of magnetic material throughout the Skagerrak and the graben, and a slight mantle upward beneath the rift zone. Petrologic and geophysical maps which depict regional structure are included in the text. An extensive bibliography of pertinent literature published in English between 1960 and 1980 is also provided.
NASA Astrophysics Data System (ADS)
Davis, Paul; Jackson, David; Gilbert, Freeman
2011-06-01
Leon Knopoff died at his home in Sherman Oaks, Calif., on 20 January 2011 at the age of 85. A man of wide-ranging talents, he had the rare distinction of being simultaneously a professor of physics, a professor of geophysics, and a research musicologist at the University of California, Los Angeles (UCLA). As an undergraduate he studied electrical engineering and obtained his Ph.D. in physics and mathematics at the California Institute of Technology (Caltech) in 1949. He was recruited to the Institute of Geophysics (now the Institute of Geophysics and Planetary Physics) at UCLA in 1950 by Louis Slichter, where he became a professor of geophysics in 1957 and of geophysics and physics in 1961. He became a research musicologist in the UCLA Institute of Ethnomusicology soon after it was formed in 1960. Other appointments included faculty positions at Miami University in Ohio (1948-1950) and Caltech (1962-1963) and visiting appointments at Cambridge, Karlsruhe, Harvard, Santiago, Trieste, and Venice.
Common interests bind AGU and geophysical groups around the globe
NASA Astrophysics Data System (ADS)
McEntee, Christine
2012-02-01
In continuation of our work to strengthen alliances with key organizations in the Earth and space science community, AGU president Michael McPhaden, president-elect Carol Finn, and I held a series of meetings with leaders from other science societies during the 2011 Fall Meeting. Over the course of 2 days we met with leaders from the Geophysical Society of America, European Geosciences Union, Japan Geosciences Union, Ethiopian Geophysical Union, Asia Oceania Geosciences Society, Chinese Geophysical Society, and Asociación Latinoamericana de Geofísica Espacial. This gave us a valued opportunity to discuss the common interests and challenges we all face and to learn from each other's experience. The meetings allowed AGU to strengthen existing cooperative agreements and reach new levels of understanding between us and other societies. Additionally, we met with representatives from the Korean Ocean Research and Development Institute to discuss their intention to establish a geophysical union modeled after AGU.
Geophysical investigations in the 100 Areas: Fiscal year 1991 through December 1993
NASA Astrophysics Data System (ADS)
Mitchell, T. H.
1994-09-01
The geophysical investigations identified in this document were conducted by the Westinghouse Hanford Company (WHC) Surface Geophysics Team, Geophysics Group, between October, 1991 and December, 1993. The investigations supported 100-Area activities for the Resource Conservation and Recovery Act of 1976 (RCRA) and the Comprehensive Environmental Response, Compensations and Liability Act of 1980 (CERCLA). The primary intent of this document is to provide a general map location and the associated document number for investigations that have been conducted as of December, 1993. The results of the individual investigations are not included here. The results of all of these investigations have been previously reported individually in WHC supporting documents. The investigations conducted during Fiscal Year (FY) 1992 are summarized in a single WHC document, WHC-SD-EN-TI-204, Rev. O. A brief summary of some of the successful applications of geophysics in the 100-Areas is included.
Anderson, J. Alton; Williams, John H.; Eckhardt, David A.V.; Miller, Todd S.
2003-01-01
Volatile-organic compounds have been detected in water sampled from more than 50 supply wells between the City of Auburn and Village of Union Springs in Cayuga County, New York, and the area was declared a Superfund site in 2002. In 2001-04, geophysical logs were collected from 37 test, monitor, and water-supply wells as a preliminary part of the investigation of volatile-organic compound contamination in the carbonate-bedrock aquifer system. The geophysical logs included gamma, induction, caliper, wellbore image, deviation, fluid resistivity and temperature, and flowmeter. The geophysical logs were analyzed along with core samples and outcrops of the bedrock to define the stratigraphic units and flow zones penetrated by the wells. This report describes the logging methods used in the study and presents the geophysical, stratigraphic, and flow-zone logs.
Brooke E. Penaluna; Steve F. Railsback; Jason B. Dunham; Sherri Johnson; Robert E. Bilby; Arne E. Skaugset; Michael Bradford
2015-01-01
The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus...
NASA Astrophysics Data System (ADS)
Opportunities to teach or perform postdoctoral research in the earth and atmospheric sciences under the Senior Scholar Fulbright awards program for 1984-1985 (Eos, March 1, 1983, p. 81) are available in 14 countries, according to the Council for International Exchange of Scholars.The countries and the specialization opportunities are Algeria, any specialization; Australia, mineral processing research; India, any specialization in geology or geophysics; Israel, environmental studies; Korea, any specialization; Lebanon, geophysics, geotectonics, and structural geology; Morocco, research methods in science education; Pakistan, geology, marine biology, and mineralogy; Poland, mining technology; Sudan, geology and remote sensing; Thailand, planning and environmental change; USSR, any specialization; Yugoslavia, any research specialization; and Zimbabwe, exploration geophysics and solid earth geophysics.
SAGE celebrates 25 years of learning geophysics by doing geophysics
Jiracek, G.R.; Baldridge, W.S.; Sussman, A.J.; Biehler, S.; Braile, L.W.; Ferguson, J.F.; Gilpin, B.E.; McPhee, D.K.; Pellerin, L.
2008-01-01
The increasing world demand and record-high costs for energy and mineral resources, along with the attendant environmental and climate concerns, have escalated the need for trained geophysicists to unprecedented levels. This is not only a national need; it's a critical global need. As Earth scientists and educators we must seriously ask if our geophysics pipeline can adequately address this crisis. One program that has helped to answer this question in the affirmative for 25 years is SAGE (Summer of Applied Geophysical Experience). SAGE continues to develop with new faculty, new collaborations, and additional ways to support student participation during and after SAGE. ?? 2008 Society of Exploration Geophysicists.
NASA Astrophysics Data System (ADS)
Schaa, R.; Gross, L.; du Plessis, J.
2016-04-01
We present a general finite-element solver, escript, tailored to solve geophysical forward and inverse modeling problems in terms of partial differential equations (PDEs) with suitable boundary conditions. Escript’s abstract interface allows geoscientists to focus on solving the actual problem without being experts in numerical modeling. General-purpose finite element solvers have found wide use especially in engineering fields and find increasing application in the geophysical disciplines as these offer a single interface to tackle different geophysical problems. These solvers are useful for data interpretation and for research, but can also be a useful tool in educational settings. This paper serves as an introduction into PDE-based modeling with escript where we demonstrate in detail how escript is used to solve two different forward modeling problems from applied geophysics (3D DC resistivity and 2D magnetotellurics). Based on these two different cases, other geophysical modeling work can easily be realized. The escript package is implemented as a Python library and allows the solution of coupled, linear or non-linear, time-dependent PDEs. Parallel execution for both shared and distributed memory architectures is supported and can be used without modifications to the scripts.
Quantum Bayesian perspective for intelligence reservoir characterization, monitoring and management
NASA Astrophysics Data System (ADS)
Lozada Aguilar, Miguel Ángel; Khrennikov, Andrei; Oleschko, Klaudia; de Jesús Correa, María
2017-10-01
The paper starts with a brief review of the literature about uncertainty in geological, geophysical and petrophysical data. In particular, we present the viewpoints of experts in geophysics on the application of Bayesian inference and subjective probability. Then we present arguments that the use of classical probability theory (CP) does not match completely the structure of geophysical data. We emphasize that such data are characterized by contextuality and non-Kolmogorovness (the impossibility to use the CP model), incompleteness as well as incompatibility of some geophysical measurements. These characteristics of geophysical data are similar to the characteristics of quantum physical data. Notwithstanding all this, contextuality can be seen as a major deviation of quantum theory from classical physics. In particular, the contextual probability viewpoint is the essence of the Växjö interpretation of quantum mechanics. We propose to use quantum probability (QP) for decision-making during the characterization, modelling, exploring and management of the intelligent hydrocarbon reservoir. Quantum Bayesianism (QBism), one of the recently developed information interpretations of quantum theory, can be used as the interpretational basis for such QP decision-making in geology, geophysics and petroleum projects design and management. This article is part of the themed issue `Second quantum revolution: foundational questions'.
Hydrologic Process-oriented Optimization of Electrical Resistivity Tomography
NASA Astrophysics Data System (ADS)
Hinnell, A.; Bechtold, M.; Ferre, T. A.; van der Kruk, J.
2010-12-01
Electrical resistivity tomography (ERT) is commonly used in hydrologic investigations. Advances in joint and coupled hydrogeophysical inversion have enhanced the quantitative use of ERT to construct and condition hydrologic models (i.e. identify hydrologic structure and estimate hydrologic parameters). However the selection of which electrical resistivity data to collect and use is often determined by a combination of data requirements for geophysical analysis, intuition on the part of the hydrogeophysicist and logistical constraints of the laboratory or field site. One of the advantages of coupled hydrogeophysical inversion is the direct link between the hydrologic model and the individual geophysical data used to condition the model. That is, there is no requirement to collect geophysical data suitable for independent geophysical inversion. The geophysical measurements collected can be optimized for estimation of hydrologic model parameters rather than to develop a geophysical model. Using a synthetic model of drip irrigation we evaluate the value of individual resistivity measurements to describe the soil hydraulic properties and then use this information to build a data set optimized for characterizing hydrologic processes. We then compare the information content in the optimized data set with the information content in a data set optimized using a Jacobian sensitivity analysis.
NASA Astrophysics Data System (ADS)
Rogelj, J.; McCollum, D. L.; Reisinger, A.; Knutti, R.; Riahi, K.; Meinshausen, M.
2013-12-01
The field of integrated assessment draws from a large body of knowledge across a range of disciplines to gain robust insights about possible interactions, trade-offs, and synergies. Integrated assessment of climate change, for example, uses knowledge from the fields of energy system science, economics, geophysics, demography, climate change impacts, and many others. Each of these fields comes with its associated caveats and uncertainties, which should be taken into account when assessing any results. The geophysical system and its associated uncertainties are often represented by models of reduced complexity in integrated assessment modelling frameworks. Such models include simple representations of the carbon-cycle and climate system, and are often based on the global energy balance equation. A prominent example of such model is the 'Model for the Assessment of Greenhouse Gas Induced Climate Change', MAGICC. Here we show how a model like MAGICC can be used for the representation of geophysical uncertainties. Its strengths, weaknesses, and limitations are discussed and illustrated by means of an analysis which attempts to integrate socio-economic and geophysical uncertainties. These uncertainties in the geophysical response of the Earth system to greenhouse gases remains key for estimating the cost of greenhouse gas emission mitigation scenarios. We look at uncertainties in four dimensions: geophysical, technological, social and political. Our results indicate that while geophysical uncertainties are an important factor influencing projections of mitigation costs, political choices that delay mitigation by one or two decades a much more pronounced effect.
The oceanic islands - Azores. [geological, geophysical and geochemical features
NASA Technical Reports Server (NTRS)
Ridley, W. I.; Watkins, N. D.; Macfarlane, D. J.
1974-01-01
A presentation is made of the known geological, geophysical, and geochemical data on the Azores. The regional setting of the islands is described; under the geological heading, surface geology and petrochemistry are discussed; and paleomagnetism, marine magnetic surveys, gravity, seismology, and heat flow are treated in the geophysics category. A model for the origin of the Azores is constructed on the basis of these observations.
Staff - Karri R. Sicard | Alaska Division of Geological & Geophysical
Raw Data File 2017-5, 26 p. http://doi.org/10.14509/29727 Todd, Erin, Kylander-Clark, Andrew, Wypych Geological & Geophysical Surveys Raw Data File 2017-2, 7 p. http://doi.org/10.14509/29717 Wypych, Alicja ; Geophysical Surveys Raw Data File 2016-9, 3 p. http://doi.org/10.14509/29685 Twelker, Evan, Freeman, L.K
SAGE (Summer of Applied Geophysical Experience): Learning Geophysics by Doing Geophysics
NASA Astrophysics Data System (ADS)
Jiracek, G. R.; Baldridge, W. S.; Biehler, S.; Braile, L. W.; Ferguson, J. F.; Gilpin, B. E.; Pellerin, L.
2005-12-01
SAGE, a field-based educational program in applied geophysical methods has been an REU site for 16 years and completed its 23rd year of operation in July 2005. SAGE teaches the major geophysical exploration methods (including seismics, gravity, magnetics, and electromagnetics) and applies them to the solution of specific local and regional geologic problems. These include delineating buried hazardous material; mapping archaeological sites; and studying the structure, tectonics, and water resources of the Rio Grande rift in New Mexico. Nearly 600 graduates, undergraduates, and professionals have attended SAGE since 1983. Since 1990 REU students have numbered 219 coming from dozens of different campuses. There have been 124 underrepresented REU students including 100 women, 14 Hispanics, 7 Native Americans, and 3 African Americans. Tracking of former REU students has revealed that 81% have gone on to graduate school. Keys to the success of SAGE are hands-on immersion in geophysics for one month and a partnership between academia, industry, and a federal laboratory. Successful approaches at SAGE include: 1) application of the latest equipment by all students; 2) continued updating of equipment, computers, and software by organizing universities and industry affiliates; 3) close ties with industry who provide supplemental instruction, furnish new equipment and software, and alert students to the current industry trends and job opportunities; 4) two-team, student data analysis structure that simultaneously addresses specific geophysical techniques and their integration; and 5) oral and written reports patterned after professional meetings and journals. An eight member, 'blue ribbon' advisory panel from academia, industry, and the federal government has been set up to maintain the vitality of SAGE by addressing such issues as funding, new faculty, organization, and vision. SAGE is open to students from any university (or organization) with backgrounds including geophysics, geology, engineering, physics, and mathematics. SAGE is sponsored by the Los Alamos National Laboratory Branch of the University of California's Institute of Geophysics and Planetary Physics. More information is available on the SAGE web site at http://www.sage.lanl.gov/.
NASA Astrophysics Data System (ADS)
Schrott, Lothar; Sass, Oliver
2008-01-01
During the last decade, the use of geophysical techniques has become popular in many geomorphological studies. However, the correct handling of geophysical instruments and the subsequent processing of the data they yield are difficult tasks. Furthermore, the description and interpretation of geomorphological settings to which they apply can significantly influence the data gathering and subsequent modelling procedure ( e.g. achieving a maximum depth of 30 m requires a certain profile length and geophone spacing or a particular frequency of antenna). For more than three decades geophysical techniques have been successfully applied, for example, in permafrost studies. However, in many cases complex or more heterogeneous subsurface structures could not be adequately interpreted due to limited computer facilities and time consuming calculations. As a result of recent technical improvements, geophysical techniques have been applied to a wider spectrum of geomorphological and geological settings. This paper aims to present some examples of geomorphological studies that demonstrate the powerful integration of geophysical techniques and highlight some of the limitations of these techniques. A focus has been given to the three most frequently used techniques in geomorphology to date, namely ground-penetrating radar, seismic refraction and DC resistivity. Promising applications are reported for a broad range of landforms and environments, such as talus slopes, block fields, landslides, complex valley fill deposits, karst and loess covered landforms. A qualitative assessment highlights suitable landforms and environments. The techniques can help to answer yet unsolved questions in geomorphological research regarding for example sediment thickness and internal structures. However, based on case studies it can be shown that the use of a single geophysical technique or a single interpretation tool is not recommended for many geomorphological surface and subsurface conditions as this may lead to significant errors in interpretation. Because of changing physical properties of the subsurface material ( e.g. sediment, water content) in many cases only a combination of two or sometimes even three geophysical methods gives sufficient insight to avoid serious misinterpretation. A "good practice guide" has been framed that provides recommendations to enable the successful application of three important geophysical methods in geomorphology and to help users avoid making serious mistakes.
NASA Astrophysics Data System (ADS)
Bernardes, Paulo; Pereira, Bruno; Alves, Mafalda; Fontes, Luís; Sousa, Andreia; Martins, Manuela; Magalhães, Fernanda; Pimenta, Mário
2017-04-01
Braga is one of the oldest cities of the Iberian NW and as of so, the research team's studying the city's historical core for the past 40 years is often confronted with the unpredictability factor laying beneath an urban site with such a long construction history. In fact, Braga keeps redesigning its urban structure over itself on for the past 2000 years, leaving us with a research object filled with an impressive set of construction footprints from the various planning decisions that were taken in the city along its historical path. Aiming for a predicting understanding of the subsoil, we have used near surface geophysics as an effort of minimizing the areas of intervention for traditional archaeological survey techniques. The Seminário de Santiago integrated geophysical survey is an example of the difficulties of interpreting geophysical models in very complex subsurface scenarios. This geophysical survey was planned in order to aid the requalification project being designed for this set of historical buildings, that are estimated to date back to the 16h century, and that were built over one of the main urban arteries of both roman and medieval layers of Braga. We have used both GPR as well as ERT methods for the geophysical survey, but for the purpose of this article, we will focus in the use of the ERT alone. For the interpretation of the geophysical models we've cross-referenced the dense knowledge existing over the building's construction phases with the complex geophysical data collected, using mathematical processing and volume-based visualization techniques, resorting to the use of Res2Inv©, Paraview© and Voxler® software's. At the same time we tried to pinpoint the noise caused by the past 30 year's infrastructural interventions regarding the replacement of the building's water and sanitation systems and for which we had no design plants, regardless of its recent occurring. The deep impact of this replacement actions revealed by the archaeological trenches, which location was selected from the results of the geophysical models interpretation, revealed to be our main unpredictability factor and, paradoxically, one of its principal results, as it will allow us to be more interpretation efficient in future geophysical surveys in the historical core. As for so, at the present we are designing an integrated geophysical research programme that will hold Braga's historical subsurface as it's open lab, aiming to develop a tool not only for archeologists and geophysicists, but also and foremost to help the city planners to design more informed, efficient and sustainable urban plans for Braga, as the city is very much alive and continually keeps on adding new layers to its urban structure.
Object-Oriented Programming When Developing Software in Geology and Geophysics
NASA Astrophysics Data System (ADS)
Ahmadulin, R. K.; Bakanovskaya, L. N.
2017-01-01
The paper reviews the role of object-oriented programming when developing software in geology and geophysics. Main stages have been identified at which it is worthwhile to apply principles of object-oriented programming when developing software in geology and geophysics. The research was based on a number of problems solved in Geology and Petroleum Production Institute. Distinctive features of these problems are given and areas of application of the object-oriented approach are identified. Developing applications in the sphere of geology and geophysics has shown that the process of creating such products is simplified due to the use of object-oriented programming, firstly when designing structures for data storage and graphical user interfaces.
Waldo E. Smith receives first award of his namesake medal
NASA Astrophysics Data System (ADS)
Smith, Waldo E.
This evening marks the first presentation of the American Geophysical Union's Waldo E. Smith Award. While all other AGU awards and honors are given for excellence in scientific research in one or another of the geophysical disciplines, this award is different. The Waldo E. Smith Award is given for dedicated and extraordinary service to geophysics and AGU. It is the principal purpose of this citation to show why it is particularly appropriate that an award for service to American geophysics should be called the Waldo E. Smith Award. A secondary objective, aimed at those present tonight, is to introduce the first recipient of this award, Waldo E. Smith, Executive Director Emeritus of AGU.
Geophysical characterisation of the groundwater-surface water interface
NASA Astrophysics Data System (ADS)
McLachlan, P. J.; Chambers, J. E.; Uhlemann, S. S.; Binley, A.
2017-11-01
Interactions between groundwater (GW) and surface water (SW) have important implications for water quantity, water quality, and ecological health. The subsurface region proximal to SW bodies, the GW-SW interface, is crucial as it actively regulates the transfer of nutrients, contaminants, and water between GW systems and SW environments. However, geological, hydrological, and biogeochemical heterogeneity in the GW-SW interface makes it difficult to characterise with direct observations. Over the past two decades geophysics has been increasingly used to characterise spatial and temporal variability throughout the GW-SW interface. Geophysics is a powerful tool in evaluating structural heterogeneity, revealing zones of GW discharge, and monitoring hydrological processes. Geophysics should be used alongside traditional hydrological and biogeochemical methods to provide additional information about the subsurface. Further integration of commonly used geophysical techniques, and adoption of emerging techniques, has the potential to improve understanding of the properties and processes of the GW-SW interface, and ultimately the implications for water quality and environmental health.
Neufeld Receives 2009 Donald L. Turcotte Award
NASA Astrophysics Data System (ADS)
2010-03-01
Jerome Neufeld has been awarded the Donald L. Turcotte Award, given annually to recent Ph.D. recipients for outstanding dissertation research that contributes directly to the field of nonlinear geophysics. Neufeld's thesis is entitled “Solidification in the fast lane: Flow-induced morphological instability in geological systems.” He was formally presented with the award at the Nonlinear Geophysics Focus Group reception during the 2009 AGU Fall Meeting, held 14-18 December in San Francisco, Calif. Jerome received his B.A.S. in engineering science from the University of Toronto in 2001, and a Ph.D. in geophysics from Yale University in 2008, under the supervision of J. S. Wettlaufer, on the impact of oceanic currents on the formation of sea ice. He is currently a fellow at the Institute of Theoretical Geophysics, University of Cambridge, working on the fluid dynamics of geophysical systems including carbon dioxide sequestration, the influence of flow on the crystal structure of mushy layers, and the evolution of icicles.
Detecting Underground Mine Voids Using Complex Geophysical Techniques
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kaminski, V. F.; Harbert, W. P.; Hammack, R. W.
2006-12-01
In July 2006, the National Energy Technology Laboratory in collaboration with Department of Geology and Planetary Science, University of Pittsburgh conducted complex ground geophysical surveys of an area known to be underlain by shallow coal mines. Geophysical methods including electromagnetic induction, DC resistivity and seismic reflection were conducted. The purpose of these surveys was to: 1) verify underground mine voids based on a century-old mine map that showed subsurface mine workings georeferenced to match with present location of geophysical test-site located on the territory of Bruceton research center in Pittsburgh, PA, 2) deliniate mine workings that may be potentially filledmore » with electrically conductive water filtrate emerging from adjacent groundwater collectors and 3) establish an equipment calibration site for geophysical instruments. Data from electromagnetic and resistivity surveys were further processed and inverted using EM1DFM, EMIGMA or Earthimager 2D capablilities in order to generate conductivity/depth images. Anomaly maps were generated, that revealed the locations of potential mine openings.« less
NASA Astrophysics Data System (ADS)
Olsen, Kenneth H.; Ansorge, Joerg
Stephan Mueller, professor emeritus at the Institute of Geophysics at the Swiss Federal Institute of Technology (ETH) in Zurich and highly respected leader of international geoscience, died February 17, 1997. His untimely death, due to pneumonia following intestinal surgery, came just 18 months after his retirement from the ETH Chair of Geophysics and Directorship of the Swiss Seismological Service. He is survived by his wife, Doris, two sons, and six grandchildren. Mueller received a diploma in physics at the University of Stuttgart in 1957 and an M.S. in electrical engineering from Columbia University in New York in 1959. As an undergraduate at Stuttgart, he was influenced by seismologist Wilhelm Hillerand geophysics quickly became his major academic and career objective. After receiving a 1954-1955 German Academic Interchange Scholarship at Columbia, Mueller sought out Maurice Ewing and his group at Lamont Geological Observatory, where Mueller's enthusiasm for geophysics was strongly encouraged. While at Lamont, he participated in the first U.S. deep-sea geophysical expedition in the Mediterranean Sea during the summer of 1956 aboard the RV Vema.
NASA Astrophysics Data System (ADS)
In recognition of the strong support of the Americn Geophysical Union and its substantial contribution to the American Geological Institute's (AGI) Minority Participation Program, 12 of the 1983-1984 AGI scholarship participants were designated “AGU Scholars.” Because part of this support comes from a matching grant from the National Oceanic and Atmospheric Administration to increase the number of minority students studying in fields related to the development of marine and coastal resources, five of these students were designated “AGU Sea Scholars.”The AGU Scholars, all of whom have elected courses of study related to the broad areas of interest of the Union, are Rufus Catchings, a geophysics graduate student at Stanford University; Charles R. Elerson, a graduate geophysics student at Louisiana Technical University; Ronald L. Keas and Orlanda M. Marques, undergraduate geophysics students at the Colorado School of Mines; Andrew Lewis Mickle, a hydrology graduate student at the University of Florida; Jaime Rangel, an undergraduate geophysics student at the University of Texas at Austin; and Ronald Wynn Sheets, a graduate geochemistry student at Ohio State University.
NASA Astrophysics Data System (ADS)
Morsy, Mona; Rashed, Mohamed
2013-01-01
Sharm El-Sheikh waters were suddenly hit by hydrocarbon spills which created a serious threat to the prosperous tourism industry in and around the city. Analysis of soil samples, water samples, and seabed samples collected in and around the contaminated bay area showed anomalous levels of hydrocarbons. An integrated geophysical investigation, using magnetic, gravity, and ground penetrating radar geophysical tools, was conducted in the headland overlooking the contaminated bay in order to delineate the possible subsurface source of contamination. The results of the geophysical investigations revealed three underground manmade reinforced concrete tanks and a complicated network of buried steel pipes in addition to other unidentified buried objects. The depths and dimensions of the discovered objects were determined. Geophysical investigations also revealed the presence of a north-south oblique slip fault running through the eastern part of the studied area. Excavations, conducted later on, confirmed the presence of one of the tanks delineated by the geophysical surveys.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1986-01-01
This study is part of a series of Studies in Geophysics that have been undertaken for the Geophysics Research Forum by the Geophysics Study Committee. One purpose of each study is to provide assessments from the scientific community to aid policymakers in decisions on societal problems that involve geophysics. An important part of such assessments is an evaluation of the adequacy of current geophysical knowledge and the appropriateness of current research programs as a source of information required for those decisions. The study addresses our current scientific understanding of active tectonics --- particularly the patterns and rates of ongoing tectonicmore » processes. Many of these processes cannot be described reasonably using the limited instrumental or historical records; however, most can be described adequately for practical purposes using the geologic record of the past 500,000 years. A program of fundamental research focusing especially on Quaternary tectonic geology and geomorphology, paleoseismology, neotectonics, and geodesy is recommended to better understand ongoing, active tectonic processes. This volume contains 16 papers. Individual papers are indexed separately on the Energy Database.« less
A method of hidden Markov model optimization for use with geophysical data sets
NASA Technical Reports Server (NTRS)
Granat, R. A.
2003-01-01
Geophysics research has been faced with a growing need for automated techniques with which to process large quantities of data. A successful tool must meet a number of requirements: it should be consistent, require minimal parameter tuning, and produce scientifically meaningful results in reasonable time. We introduce a hidden Markov model (HMM)-based method for analysis of geophysical data sets that attempts to address these issues.
Geophysical Measurements of Basalt Intraflow Structures.
1997-12-01
COVERED Final 4. TITLE AND SUBTITLE Geophysical Measurements of Basalt Intraflow Structures 6. AUTHOR(S) William K. Hudson 7. PERFORMING...horm 29B (Hi ^ 29 ev. 5-88) by ANISE Sad Z39-18 Prescribed 298-102 GEOPHYSICAL MEASUREMENTS OF BASALT INTRAFLOW STRUCTURES by William K. Hudson A...region. The physical properties of basalt can change dramatically within a single flow and may be associated with changes in intraflow structure. The
Looking Forward to the electronic Geophysical Year
NASA Astrophysics Data System (ADS)
Kamide, Y.; Baker, D. N.; Thompson, B.; Barton, C.; Kihn, E.
2004-12-01
During the International Geophysical Year (1957-1958), member countries established many new capabilities pursuing the major IGY objectives of collecting geophysical data as widely as possible and providing free access to these data for all scientists around the globe. A key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories. The worldwide scientific community has now endorsed and is promoting an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the 50th anniversary of the IGY in 2007-2008 and would provide a forward impetus to geophysics in the 21st century, similar to that provide by the IGY fifty years ago. The eGY concept advocates the establishment of a series of virtual geophysical observatories now being deployed in cyberspace. We discuss plans to aggregate measurements into a readily accessible database along with analysis, visualization, and display tools that will make information available and useful to the scientific community, to the user community, and to the general public. We are examining the possibilities for near-realtime acquisition of data and utilization of forecast tools in order to provide users with advanced space weather capabilities. This program will provide powerful tools for education and public outreach concerning the connected Sun-Earth System.
An electromagnetic geophysical survey of the freshwater lens of Isla de Mona, Puerto Rico
Richards, R.T.; Troester, J.W.; Martinez, M.I.
1998-01-01
An electromagnetic reconnaissance of the freshwater lens of Isla de Mona, Puerto Rico was conducted with both terrain conductivity (TC) and transient electromagnetic (TEM) surface geophysical techniques. These geophysical surveys were limited to the southern and western parts of the island because of problems with access and cultural metallic objects such as reinforced concrete roadways on the eastern part of the island. The geophysical data were supplemented with the location of a freshwater spring found by scuba divers at a depth of about 20 m below sea level along the northern coast of the island. The geophysical data suggest that the freshwater lens has a maximum thickness of 20 m in the southern half of the island. The freshwater lens is not thickest at the center of the island but nearer the southwestern edge in Quaternary deposits and the eastern edge of the island in the Tertiary carbonates. This finding indicates that the groundwater flow paths on Isla de Mona are not radially summetrical from the center of the island to the ocean. The asymmetry of the freshwater lens indicates that the differences in hydraulic conductivity are a major factor in determining the shape of the freshwater lens. The porosity of the aquifer, as determined by the geophysical data is about 33%.
Quantum Bayesian perspective for intelligence reservoir characterization, monitoring and management.
Lozada Aguilar, Miguel Ángel; Khrennikov, Andrei; Oleschko, Klaudia; de Jesús Correa, María
2017-11-13
The paper starts with a brief review of the literature about uncertainty in geological, geophysical and petrophysical data. In particular, we present the viewpoints of experts in geophysics on the application of Bayesian inference and subjective probability. Then we present arguments that the use of classical probability theory (CP) does not match completely the structure of geophysical data. We emphasize that such data are characterized by contextuality and non-Kolmogorovness (the impossibility to use the CP model), incompleteness as well as incompatibility of some geophysical measurements. These characteristics of geophysical data are similar to the characteristics of quantum physical data. Notwithstanding all this, contextuality can be seen as a major deviation of quantum theory from classical physics. In particular, the contextual probability viewpoint is the essence of the Växjö interpretation of quantum mechanics. We propose to use quantum probability (QP) for decision-making during the characterization, modelling, exploring and management of the intelligent hydrocarbon reservoir Quantum Bayesianism (QBism), one of the recently developed information interpretations of quantum theory, can be used as the interpretational basis for such QP decision-making in geology, geophysics and petroleum projects design and management.This article is part of the themed issue 'Second quantum revolution: foundational questions'. © 2017 The Author(s).
Geophysical background and as-built target characteristics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allen, J.W.
1994-09-01
The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) has provided a facility for DOE, other Government agencies, and the private sector to evaluate and document the utility of specific geophysical measurement techniques for detecting and defining cultural and environmental targets. This facility is the Rabbit Valley Geophysics Performance Evaluation Range (GPER). Geophysical surveys prior to the fiscal year (FY) 1994 construction of new test cells showed the primary test area to be relatively homogeneous and free from natural or man-made artifacts, which would generate spurious responses in performance evaluation data. Construction of nine new cell areas inmore » Rabbit Valley was completed in June 1994 and resulted in the emplacement of approximately 150 discrete targets selected for their physical and electrical properties. These targets and their geophysical environment provide a broad range of performance evaluation parameters from ``very easy to detect`` to ``challenging to the most advanced systems.`` Use of nonintrusive investigative techniques represents a significant improvement over intrusive characterization methods, such as drilling or excavation, because there is no danger of exposing personnel to possible hazardous materials and no risk of releasing or spreading contamination through the characterization activity. Nonintrusive geophysical techniques provide the ability to infer near-surface structure and waste characteristics from measurements of physical properties associated with those targets.« less
NASA Astrophysics Data System (ADS)
Ruggeri, Paolo; Irving, James; Gloaguen, Erwan; Holliger, Klaus
2013-04-01
Significant progress has been made with regard to the quantitative integration of geophysical and hydrological data at the local scale. However, extending corresponding approaches to the regional scale still represents a major challenge, yet is critically important for the development of groundwater flow and contaminant transport models. To address this issue, we have developed a regional-scale hydrogeophysical data integration technique based on a two-step Bayesian sequential simulation procedure. The objective is to simulate the regional-scale distribution of a hydraulic parameter based on spatially exhaustive, but poorly resolved, measurements of a pertinent geophysical parameter and locally highly resolved, but spatially sparse, measurements of the considered geophysical and hydraulic parameters. To this end, our approach first involves linking the low- and high-resolution geophysical data via a downscaling procedure before relating the downscaled regional-scale geophysical data to the high-resolution hydraulic parameter field. We present the application of this methodology to a pertinent field scenario, where we consider collocated high-resolution measurements of the electrical conductivity, measured using a cone penetrometer testing (CPT) system, and the hydraulic conductivity, estimated from EM flowmeter and slug test measurements, in combination with low-resolution exhaustive electrical conductivity estimates obtained from dipole-dipole ERT meausurements.
Cassiani, Giorgio; Binley, Andrew; Kemna, Andreas; Wehrer, Markus; Orozco, Adrian Flores; Deiana, Rita; Boaga, Jacopo; Rossi, Matteo; Dietrich, Peter; Werban, Ulrike; Zschornack, Ludwig; Godio, Alberto; JafarGandomi, Arash; Deidda, Gian Piero
2014-01-01
The characterization of contaminated sites can benefit from the supplementation of direct investigations with a set of less invasive and more extensive measurements. A combination of geophysical methods and direct push techniques for contaminated land characterization has been proposed within the EU FP7 project ModelPROBE and the affiliated project SoilCAM. In this paper, we present results of the investigations conducted at the Trecate field site (NW Italy), which was affected in 1994 by crude oil contamination. The less invasive investigations include ground-penetrating radar (GPR), electrical resistivity tomography (ERT), and electromagnetic induction (EMI) surveys, together with direct push sampling and soil electrical conductivity (EC) logs. Many of the geophysical measurements were conducted in time-lapse mode in order to separate static and dynamic signals, the latter being linked to strong seasonal changes in water table elevations. The main challenge was to extract significant geophysical signals linked to contamination from the mix of geological and hydrological signals present at the site. The most significant aspects of this characterization are: (a) the geometrical link between the distribution of contamination and the site's heterogeneity, with particular regard to the presence of less permeable layers, as evidenced by the extensive surface geophysical measurements; and (b) the link between contamination and specific geophysical signals, particularly evident from cross-hole measurements. The extensive work conducted at the Trecate site shows how a combination of direct (e.g., chemical) and indirect (e.g., geophysical) investigations can lead to a comprehensive and solid understanding of a contaminated site's mechanisms.
NASA Astrophysics Data System (ADS)
Che-Alota, V.; Atekwana, E. A.; Sauck, W. A.; Nolan, J. T.; Slater, L. D.
2007-12-01
Previous geophysical investigations (1996, 1997, 2003, and 2004) conducted at the decommissioned Wurtsmith Air Force Base former Fire Training Cell (FT-02) showed a clearly defined high conductivity anomaly associated with hydrocarbon contaminants in the vadose zone and ground water near the source area. The source of the geophysical anomalies was attributed to biogeochemical modifications of the contaminated zone resulting from intrinsic bioremediation. During these previous surveys, ground penetrating radar (GPR) data showed a zone of attenuated GPR reflections extending from the vadose zone to below the water table. Self potential data (SP) data defined a positive anomaly coincident with the hydrochemically defined plume, while electrical resistivity data showed anomalously high conductivity within the zone of impact. In 2007, another integrated geophysical study of the site was conducted. GPR, SP, electrical resistivity, and induced polarization surveys were conducted with expectations of achieving similar results as the past surveys. However, preliminary assessment of the data shows a marked decrease in electrical conductivity and SP response over the plume. GPR data still showed the attenuated signals, but the zone of attenuation was only observed below the water table. We attribute the attenuation of the observed geophysical anomalies to ongoing soil vapor extraction initiated in 2003. Significant removal of the contaminant mass by the vapor extraction system has altered the subsurface biogeochemical conditions and these changes were documented by the 2007 geophysical and geochemical data. The results of this study show that the attenuation of the contaminant plume is detectable with geophysical methods.
ERIC Educational Resources Information Center
Savit, Carl H.
1978-01-01
Expansion of activity and confirmation of new technological directions characterized several fields of exploration geophysics in 1977. Advances in seismic-reflection exploration have been especially important. (Author/MA)
Investigation of coastal areas in Northern Germany using airborne geophysical surveys
NASA Astrophysics Data System (ADS)
Miensopust, Marion; Siemon, Bernhard; Wiederhold, Helga; Steuer, Annika; Ibs-von Seht, Malte; Voß, Wolfgang; Meyer, Uwe
2014-05-01
Since 2000, the German Federal Institute for Geosciences and Natural Resources (BGR) carried out several airborne geophysical surveys in Northern Germany to investigate the coastal areas of the North Sea and some of the North and East Frisian Islands. Several of those surveys were conducted in cooperation with the Leibniz Institute for Applied Geophysics (LIAG). Two helicopter-borne geophysical systems were used, namely the BGR system, which collects simultaneously frequency-domain electromagnetic, magnetic and radiometric data, and the SkyTEM system, a time-domain electromagnetic system developed by the University of Aarhus. Airborne geophysical surveys enable to investigate huge areas almost completely with high lateral resolution in a relatively short time at economic cost. In general, the results can support geological and hydrogeological mapping. Of particular importance are the airborne electromagnetic results, as the surveyed parameter - the electrical conductivity - depends on both lithology and groundwater status. Therefore, they can reveal buried valleys and the distribution of sandy and clayey sediments as well as salinization zones and fresh-water occurrences. The often simultaneously recorded magnetic and radiometric data support the electromagnetic results. Lateral changes of Quaternary and Tertiary sediments (shallow source - several tens of metres) as well as evidences of the North German Basin (deep source - several kilometres) are revealed by the magnetic results. The radiometric data indicate the various mineral compositions of the soil sediments. This BGR/LIAG project aims to build up a geophysics data base (http://geophysics-database.de/) which contains all airborne geophysical data sets. However, the more significant effort is to create a reference data set as basis for monitoring climate or man-made induced changes of the salt-water/fresh-water interface at the German North Sea coast. The significance of problems for groundwater extraction and treatment caused by groundwater salinization is more and more increasing and particularly coastal areas are affected by a latent risk for the sustainable usage of aquifers.
A Bayesian trans-dimensional approach for the fusion of multiple geophysical datasets
NASA Astrophysics Data System (ADS)
JafarGandomi, Arash; Binley, Andrew
2013-09-01
We propose a Bayesian fusion approach to integrate multiple geophysical datasets with different coverage and sensitivity. The fusion strategy is based on the capability of various geophysical methods to provide enough resolution to identify either subsurface material parameters or subsurface structure, or both. We focus on electrical resistivity as the target material parameter and electrical resistivity tomography (ERT), electromagnetic induction (EMI), and ground penetrating radar (GPR) as the set of geophysical methods. However, extending the approach to different sets of geophysical parameters and methods is straightforward. Different geophysical datasets are entered into a trans-dimensional Markov chain Monte Carlo (McMC) search-based joint inversion algorithm. The trans-dimensional property of the McMC algorithm allows dynamic parameterisation of the model space, which in turn helps to avoid bias of the post-inversion results towards a particular model. Given that we are attempting to develop an approach that has practical potential, we discretize the subsurface into an array of one-dimensional earth-models. Accordingly, the ERT data that are collected by using two-dimensional acquisition geometry are re-casted to a set of equivalent vertical electric soundings. Different data are inverted either individually or jointly to estimate one-dimensional subsurface models at discrete locations. We use Shannon's information measure to quantify the information obtained from the inversion of different combinations of geophysical datasets. Information from multiple methods is brought together via introducing joint likelihood function and/or constraining the prior information. A Bayesian maximum entropy approach is used for spatial fusion of spatially dispersed estimated one-dimensional models and mapping of the target parameter. We illustrate the approach with a synthetic dataset and then apply it to a field dataset. We show that the proposed fusion strategy is successful not only in enhancing the subsurface information but also as a survey design tool to identify the appropriate combination of the geophysical tools and show whether application of an individual method for further investigation of a specific site is beneficial.
ERIC Educational Resources Information Center
Espey, H. R.
1977-01-01
Describes geophysical techniques such as seismic, gravity, and magnetic surveys of offshare acreage, and land-data gathering from a three-dimensional representation made from closely spaced seismic lines. (MLH)
NASA Astrophysics Data System (ADS)
Eppelbaum, Lev
2010-05-01
It is obvious that noninvasive geophysical methods are the main interpreting tools at the areas of world recognized religious and cultural artifacts. Usually in these areas any excavations, drilling and infrastructure activity are forbidden or very strongly limited. According to field experience and results of numerous modeling (Eppelbaum, 1999, 2000, 2009a, 2009b; Eppelbaum and Itkis, 2001, 2003; Eppelbaum et al., 2000, 2001a, 2001b, 2003a, 2006a, 2006b, 2007, 2010, Itkis et al., 2003; Neishtadt et al., 2006), a set of applied geophysical methods may include the following types of surveys: (1) magnetic, (3) GPR (ground penetration radar), (3) gravity, (4) electromagnetic VLF (very low frequency), (5) ER (electric resistivity), (6) SP (self-potential), (7) IP (induced polarization), (8) SE (seismoelectric), and (9) NST (near-surface temperature). As it was shown in (Eppelbaum, 2005), interpretation ambiguity may be sufficiently reduced not only by integrated analysis of several geophysical methods, but also by the way of multilevel observations of geophysical fields. Magnetic, gravity and VLF measurements may be performed at different levels over the earth's surface (0.1 - 3 m), ER, SP and SE observations may be obtained with different depth of electrodes grounding (0.1 - 1 m), and NST sensor may be located at a depth of 0.8 - 2.5 m. GPR method usually allows measuring electromagnetic fields at various frequencies (with corresponding changing of the investigation depth and other parameters). Influence of some typical noise factors to geophysical investigations at archaeological sites was investigated in (Eppelbaum and Khesin, 2001). In many cases various constructions and walls are in the nearest vicinity of the examined artifacts. These constructions can be also utilized for carrying out geophysical measurements (magnetic, gravity and VLF) at different levels. Application of the modern ROV (remote operated vehicles) with registration of magnetic and VLF fields at 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 Geophysics to Engineering and Environmental Problems, Philadelphia, USA, 938-963. Eppelbaum, L.V., 2009a. Near-surface temperature survey: An independent tool for buried archaeological targets delineation. Journal of Cultural Heritage, 12, Suppl.1, e93-e103. Eppelbaum, L.V., 2009b. Application of microgravity at archaeological sites in Israel: some estimation derived from 3D modeling and quantitative analysis of gravity field. Proceed. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems, Denver, USA, 22, No. 1, 434-446. Eppelbaum, L. and Ben-Avraham, Z., 2002. On the development of 4D geophysical Data Base of archaeological sites in Israel. Trans. of the Conf. of the Israel Geol. Soc. Ann. Meet., MaHagan - Lake Kinneret, Israel, p.21. Eppelbaum, L., Eppelbaum,V. and Ben-Avraham, Z., 2003. Formalization and estimation of integrated geological investigations: Informational Approach. Geoinformatics, 14, No.3, 233-240. Eppelbaum, L., Ben-Avraham, Z. and Itkis, S., 2003a. Ancient Roman Remains in Israel provide a challenge for physical-archaeological modeling techniques. First Break, 21 (2), 51-61. Eppelbaum, L., Ben-Avraham, Z., Itkis, S., and Kouznetsov, S., 2001a. First results of self-potential method application at archaeological sites in Israel. Trans. of the EUG XI Intern. Symp., Strasbourg, France, p. 657. Eppelbaum, L.V. and Itkis, S.E., 2001. Detailed magnetic investigations at the ancient Roman site Banias II (northern Israel). Proceed. of the 1st Intern Symp. on Soil and Archaeology, Szazhalombatta, Hungary, 13-16. Eppelbaum, L.V. and Itkis, S.E., 2003. Geophysical examination of the archaeological site Emmaus-Nicopolis (central Israel). Collection of Papers of the XIXth International UNESCO Symposium 'New Perspectives to Save the Cultural Heritage', Antalya, Turkey, 395-400. Eppelbaum, L.V., Itkis, S.E., Fleckenstein, K.-H., and Fleckenstein, L., 2007. Latest results of geophysical-archaeological investigations at the Christian archaeological site Emmaus-Nicopolis (central Israel). Proceed. of the 69th EAGE Conference, P118, London, Great Britain, 5 pp. Eppelbaum, L.V., Itkis, S.E., and Khesin, B.E., 2000. Optimization of magnetic investigations in the archaeological sites in Israel. In: Special Issue of Prospezioni Archeologiche 'Filtering, Modeling and Interpretation of Geophysical Fields at Archaeological Objects', 65-92. Eppelbaum, L., Itkis, S., and Khesin, B., 2006a. Detailed magnetic survey unmasks Prehistoric archaeological sites in Israel. Proceed. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems, Calgary, Canada, 1366-1373. Eppelbaum, L.V. and Khesin, B.E., 2001. Disturbing factors in geophysical investigations at archaeological sites and ways of their elimination. Trans. of the IV Conf. on Archaeological Prospection, Vienna, Austria, 99-101. Eppelbaum, L.V., Khesin, B.E., and Itkis, S.E., 2001b. Prompt magnetic investigations of archaeological remains in areas of infrastructure development: Israeli experience. Archaeological Prospection, 8 (3), 163-185. Eppelbaum, L.V., Khesin, B.E., and Itkis, S.E., 2006b. Some peculiarities of geophysical investigations at archaeological sites in Israel. Russian Archaeology, No. 1, 59-70. Eppelbaum, L.V., Khesin, B.E., and Itkis, S.E., 2010. Archaeological geophysics in arid environments: Examples from Israel. Journal of Arid Environments, 74, No. 5. Eppelbaum, L.V., Kutasov, I.M. and Barak, G., 2006c. Ground surface temperature histories inferred from 15 boreholes temperature profiles: Comparison of two approaches. Earth Sciences Research Journal, 10, No. 1, 25-34. Finkelstein, M.I. and Eppelbaum, L.V., 1997. Classification of the disturbing objects using interpretation of low-intensive temporary magnetic variations. Trans. of the Conference of Geological Society of America. Salt Lake City, 29, No.6, p. 326. Itkis, S., Khesin, B., Eppelbaum, L., and Khalaily, H., 2003. The Natufian site of Eynan (Hula valley, northern Israel): Magnetic prospecting reveals new features. Israel Journal of Earth Sciences, 52 (3-4), 209-219. Khesin, B.E., Alexeyev, V.V. and Eppelbaum, L.V., 1996. Interpretation of Geophysical Fields in Complicated Environments. Kluwer Academic Publishers, Ser.: Modern Approaches in Geophysics, Boston - Dordrecht - London, 368 pp. Neishtadt, N., Eppelbaum, L. and Levitski, A., 2006. Application of seismo-electric phenomena in exploration geophysics: Review of Russian and Israeli experience. Geophysics, 71, No.2, B41-B53.
The remote sensing needs of Arctic geophysics
NASA Technical Reports Server (NTRS)
Campbell, W. J.
1970-01-01
The application of remote sensors for obtaining geophysical information of the Arctic regions is discussed. Two significant requirements are to acquire sequential, synoptic imagery of the Arctic Ocean during all weather and seasons and to measure the strains in the sea ice canopy and the heterogeneous character of the air and water stresses acting on the canopy. The acquisition of geophysical data by side looking radar and microwave sensors in military aircraft is described.
Fractional properties of geophysical field variability on the example of hydrochemical parameters
NASA Astrophysics Data System (ADS)
Shevtsov, Boris; Shevtsova, Olga
2017-10-01
Using the properties of compound Poisson process and its fractional generalizations, statistical models of geophysical fields variability are considered on an example of hydrochemical parameters system. These models are universal to describe objects of different nature and allow us to explain various pulsing regime. Manifestations of non-conservatism in hydrochemical parameters system and the advantages of the system approach in the description of geophysical fields variability are discussed.
Identifying Fossil Shell Resources via Geophysical Surveys: Chesapeake Bay Region, Virginia
2016-05-01
ER D C/ CH L TR -1 6- 4 Chesapeake Fossil Shell Survey Identifying Fossil Shell Resources via Geophysical Surveys: Chesapeake Bay Region...other technical reports published by ERDC, visit the ERDC online library at http://acwc.sdp.sirsi.net/client/default. Chesapeake Fossil Shell...Survey ERDC/CHL TR-16-4 May 2016 Identifying Fossil Shell Resources via Geophysical Surveys: Chesapeake Bay Region, Virginia Heidi M. Wadman and Jesse
2005-12-01
helicopter geophysical survey performed by US Army Engineering Support Center, Huntsville (USAESCH) and Oak Ridge National Laboratory ( ORNL ) over areas...Array Detection System NAD North American Datum ORAGS Oak Ridge Airborne Geophysical System ORNL Oak Ridge National Laboratory RMS Root...used by ORNL in 1999 for.....................5 Figure 2.4 ORAGS-Hammerhead airborne magnetometer system used at Badlands Bombing Range in FY2000
Payload-Directed Control of Geophysical Magnetic Surveys
NASA Technical Reports Server (NTRS)
Lee, Ritchie; Yeh, Yoo-Hsiu; Ippolito, Corey; Spritzer, John; Phelps, Geoffrey
2010-01-01
Using non-navigational (e.g. imagers, scientific) sensor information in control loops is a difficult problem to which no general solution exists. Whether the task can be successfully achieved in a particular case depends highly on problem specifics, such as application domain and sensors of interest. In this study, we investigate the feasibility of using magnetometer data for control feedback in the context of geophysical magnetic surveys. An experimental system was created and deployed to (a) assess sensor integration with autonomous vehicles, (b) investigate how magnetometer data can be used for feedback control, and (c) evaluate the feasibility of using such a system for geophysical magnetic surveys. Finally, we report the results of our experiments and show that payload-directed control of geophysical magnetic surveys is indeed feasible.
Aeromagnetic Survey in Afghanistan: A Website for Distribution of Data
Abraham, Jared D.; Anderson, Eric D.; Drenth, Benjamin J.; Finn, Carol A.; Kucks, Robert P.; Lindsay, Charles R.; Phillips, Jeffrey D.; Sweeney, Ronald E.
2007-01-01
Afghanistan's geologic setting indicates significant natural resource potential While important mineral deposits and petroleum resources have been identified, much of the country's potential remains unknown. Airborne geophysical surveys are a well accepted and cost effective method for obtaining information of the geological setting of an area without the need to be physically located on the ground. Due to the security situation and the large areas of the country of Afghanistan that has not been covered with geophysical exploration methods a regional airborne geophysical survey was proposed. Acting upon the request of the Islamic Republic of Afghanistan Ministry of Mines, the U.S. Geological Survey contracted with the Naval Research Laboratory to jointly conduct an airborne geophysical and remote sensing survey of Afghanistan.
Geophysical Methods for Investigating Ground-Water Recharge
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 that are currently available or under development for recharge monitoring. The material is written primarily for hydrogeologists. Uses of geophysical methods for improving recharge monitoring are explored through brief discussions and case studies. The intent is to indicate how geophysical methods can be used effectively in studying recharge processes and quantifying recharge. As such, the material constructs a framework for matching the strengths of individual geophysical methods with the manners in which they can be applied for hydrologic analyses. The appendix is organized in three sections. First, the key hydrologic parameters necessary to determine the rate, timing, and patterns of recharge are identified. Second, the basic operating principals of the relevant geophysical methods are discussed. Methods are grouped by the physical property that they measure directly. Each measured property is related to one or more of the key hydrologic properties for recharge monitoring. Third, the emerging conceptual framework for applying geophysics to recharge monitoring is presented. Examples of the application of selected geophysical methods to recharge monitoring are presented in nine case studies. These studies illustrate hydrogeophysical applications under a wide range of conditions and measurement scales, which vary from tenths of a meter to hundreds of meters. The case studies include practice-proven as well as emerging applications of geophysical methods to recharge monitoring.
The World Data Fabric: A New Concept for Geophysical Data Collection and Dissemination
NASA Astrophysics Data System (ADS)
Papitashvili, V.; Papitashvili, N.
2005-12-01
Nowadays, a multitude of digital geophysical data have become available via the World Wide Web from a variety of sources, including the World Data Centers (WDC), their suppliers (discipline-specific observatories, research institutions, government agencies), and short-lived, sporadic datasets produced by individual investigators from their research grants. As a result, worldwide geophysical databases become diverse and distributed, urging for sophisticated search engines capable of identifying discipline-specific data on the Web and then retrieving requested intervals for scientific analyses or practical applications. Here we introduce a concept of the World Data Fabric (WDF) emerged from the essence of World Data Centers system that successfully served geophysical communities since the International Geophysical Year (1957-58). We propose to unify both components of the WDC System - data centers and data providers - into a worldwide data network (data fabric), where the WDC role would become more proactive through their direct interaction with the data producers. It suggested that the World Data Centers would become a backbone of the World Data Fabric, watching and copying newly ``Webbed'' geophysical data to the center archives - to preserve at least 2-3 copies (or as many as Centers exist) of the new datasets within the entire WDF. Thus, the WDF would become a self-organized system of the data nodes (providers) and data portals (the WDCs as``clearinghouse''). The WDF would be then developing similarly to the Web, but its focus would be on geophysical data rather than on the content of a specific geophysical discipline. Introducing the WDF concept, we face a number of challenges: (a) data providers should make their datasets available via the Internet using open (but secure) access protocols; (b) multiple copies of every dataset would spread across WDF; (c) every WDF dataset (original or copied) must be digitally signed by the data providers and then by the data copiers; and (c) the WDF datasets must be protected from deliberate corruption or hacking. As the WDF (for all or specific geophysical disciplines) is established and actively maintained by a series of policies and regulations (i.e., specific for a particular discipline) through the WDC activities, then one can write a specific middleware to retrieve required data from the ``data fabric'', building then either the specific Virtual Observatory or Distributed Data System. The presentation will address these challenges suggesting some immediate and intervening solutions.
Teaching Computational Geophysics Classes using Active Learning Techniques
NASA Astrophysics Data System (ADS)
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.
pyGIMLi: An open-source library for modelling and inversion in geophysics
NASA Astrophysics Data System (ADS)
Rücker, Carsten; Günther, Thomas; Wagner, Florian M.
2017-12-01
Many tasks in applied geosciences cannot be solved by single measurements, but require the integration of geophysical, geotechnical and hydrological methods. Numerical simulation techniques are essential both for planning and interpretation, as well as for the process understanding of modern geophysical methods. These trends encourage open, simple, and modern software architectures aiming at a uniform interface for interdisciplinary and flexible modelling and inversion approaches. We present pyGIMLi (Python Library for Inversion and Modelling in Geophysics), an open-source framework that provides tools for modelling and inversion of various geophysical but also hydrological methods. The modelling component supplies discretization management and the numerical basis for finite-element and finite-volume solvers in 1D, 2D and 3D on arbitrarily structured meshes. The generalized inversion framework solves the minimization problem with a Gauss-Newton algorithm for any physical forward operator and provides opportunities for uncertainty and resolution analyses. More general requirements, such as flexible regularization strategies, time-lapse processing and different sorts of coupling individual methods are provided independently of the actual methods used. The usage of pyGIMLi is first demonstrated by solving the steady-state heat equation, followed by a demonstration of more complex capabilities for the combination of different geophysical data sets. A fully coupled hydrogeophysical inversion of electrical resistivity tomography (ERT) data of a simulated tracer experiment is presented that allows to directly reconstruct the underlying hydraulic conductivity distribution of the aquifer. Another example demonstrates the improvement of jointly inverting ERT and ultrasonic data with respect to saturation by a new approach that incorporates petrophysical relations in the inversion. Potential applications of the presented framework are manifold and include time-lapse, constrained, joint, and coupled inversions of various geophysical and hydrological data sets.
Broadband geophysical time series data from a stressed environment
NASA Astrophysics Data System (ADS)
Pun, W.; Saleh, R.; Zwaan, D.; Milkereit, B.; Valley, B.; Pilz, M.; Milkereit, C.; Milkereit, R.
2011-12-01
As classical exploration geophysical tools and techniques find new application in time lapse and monitoring studies, a fresh look at the performance and repeatability of various geophysical techniques is worth to take a closer look. We used an active, deep mine site close to Sudbury (Canada) for 3D deployment of broadband geophysical sensors for passive monitoring and detecting anomalous regions in the earth based on physical rock properties. In addition, we conducted controlled source experiments to evaluate repeatability of geophysical sources. To extend from detection to monitoring, continuous repeated measurements are necessary over a long period of time. If a controlled source is stable, the convolution problem is simplified such that any variation in the geophysical data is an effect of the earth's response. Repeated measurements are important for in-mine use to provide a better insight of stress and strain changes due to natural events and mining processes. The development, build-up and redistribution of stress lead to rock failures that can have disastrous consequences if they occur in an uncontrolled manner. In this project, different continuous and repeated in-situ geophysical measurements from a deep underground mine were analyzed to validate the feasibility of in-mine monitoring. Data acquisition tests covered both active and passive methods: gravity meter, fibre optic strain meters, fixed and portable three-component seismic arrays, EM induction coils and borehole based DC/IP resistivity sensors. The newly acquired data cover a wide range of frequencies which allow the study of short- and long-period events, ranging from 10-5 Hz to 10 kHz. Earth tides, global seismic events, tremors, acoustic emissions (microseismic events) and blasts were recorded within a 3D volume.
Archaeological Feedback as a Research Methodology in Near-Surface Geophysics
NASA Astrophysics Data System (ADS)
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 geophysical methods.
Integrated Approaches On Archaeo-Geophysical Data
NASA Astrophysics Data System (ADS)
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 during the field work.
NASA Astrophysics Data System (ADS)
Schertzer, D. J.; Tchiguirinskaia, I.; Lovejoy, S.
2013-12-01
Fractals and multifractals are very illustrative of the profound synergies between mathematics and geophysics. The book ';Fractal Geometry of Nature' (Mandelbrot, 1982) brilliantly demonstrated the genericity in geophysics of geometric forms like Cantor set, Peano curve and Koch snowflake, which were once considered as mathematical monsters. However, to tame the geophysical monsters (e.g. extreme weather, floods, earthquakes), it was required to go beyond geometry and a unique fractal dimension. The concept of multifractal was coined in the course of rather theoretical debates on intermittency in hydrodynamic turbulence, sometimes with direct links to atmospheric dynamics. The latter required a generalized notion of scale in order to deal both with scale symmetries and strong anisotropies (e.g. time vs. space, vertical vs. horizontal). It was thus possible to show that the consequences of intermittency are of first order, not just 'corrections' with respect to the classical non-intermittent modeling. This was in fact a radical paradigm shift for geophysics: the extreme variability of geophysical fields over wide ranges of scale, which had long been so often acknowledged and deplored, suddenly became handy. Recent illustrations are the possibility to track down in large date sets the Higgs boson of intermittence, i.e. a first order multifractal phase transition leading to self-organized criticality, and to simulate intermittent vector fields with the help of Lie cascades, based for instance on random Clifford algebra. It is rather significant that this revolution is no longer limited to fundamental and theoretical problems of geophysics, but now touches many applications including environmental management, in particular for urban management and resilience. These applications are particularly stimulating when taken in their full complexity.
The 1990 Western Pacific Geophysics meeting
NASA Technical Reports Server (NTRS)
1990-01-01
The 1990 Western Pacific Geophysics Meeting was held in Kanazawa, Japan from 15-21 Aug. 1990. This was the first meeting of a new series of meetings for the American Geophysical Union, and it proved to be very successful in terms of the scientific program and attendance, which included over 1,000 participants. The intent of this meeting was an effort on the part of the American Geophysical Union (AGU) and several Japanese geophysical societies to gather individual Earth and space scientists at a major scientific meeting to focus on geophysical problems being studied in the western Pacific rim. The meeting was organized along the lines of a typical AGU annual meeting with some invited talks, many contributed talks, poster sessions, and with emphasis on presentations and informal discussions. The program committee consisted of scientists from both the U.S. and Japan. This meeting provided ample opportunities for U.S. and Japanese scientists to get to know each other and their works on a one-to-one basis. It was also a valuable opportunity for students studying geophysics to get together and interact with each other and with scientists from both the U.S. and Japan. There were 939 abstracts submitted to the conference and a total of 102 sessions designed as a result of the abstracts received. The topics of interest are as follows: space geodetic and observatory measurements for earthquake and tectonic studies; gravity, sea level, and vertical motion; variations in earth rotation and earth dynamics; sedimentary magnetism; global processes and precipitation; subsurface contaminant transport; U.S. Western Pacific Rim initiatives in hydrology; shelf and coastal circulation; tectonics, magmatism, and hydrothermal processes; earthquake prediction and hazard assessment; seismic wave propagation in realistic media; and dynamics and structure of plate boundaries and of the Earth's deep interior.
Increasing diversity in the geosciences through the AfricaArray geophysics field course
NASA Astrophysics Data System (ADS)
Vallejo, G.; Emry, E.; Galindo, B. L.; Carranza, V.; Gomez, C. D.; Ortiz, K.; Castro, J. G.; Guandique, J.; Falzone, C.; Webb, S. J.; Manzi, M.; Mngadi, S. B.; Stephens, K.; Chinamora, B.; Whitehead, R.; de Villiers, D. P.; Tshitlho, K.; Delhaye, R. P.; Smith, J. A.; Nyblade, A.
2014-12-01
For the past nine years, the AfricaArray diversity program, sponsored by industry, the National Science Foundation, and several partnering universities have supported outstanding U.S. STEM underrepresented minority undergraduates to gain field experience in near-surface geophysical techniques during an 8-week summer program at Penn State University and the University of Witwatersrand (Wits). The AfricaArray geophysics field school, which is run by Wits, has been teaching field-based geophysics to African students for over a decade. In the first 2-3 weeks of the program, the U.S. students are given basic instruction in near-surface geophysics, South African geology, and South African history and culture. The students then join the Wits AfricaArray geophysics field school - working alongside Wits students and students from several other African universities to map the shallow subsurface in prospective areas of South Africa for platinum mining. In addition to the primary goals of collecting and interpreting gravity, magnetic, resistivity, seismic refraction, seismic reflection, and EM data, students spend time mapping geologic units and gathering information on the physical properties of the rocks in the region (i.e. seismic velocity, density, and magnetic susceptibility). Subsurface targets include mafic dikes, faults, the water table, and overburden thickness. Upon returning to the U.S., students spend 2-3 weeks finalizing their project reports and presentations. The program has been effective at not only providing students with fundamental skills in applied geophysics, but also in fostering multicultural relationships, preparing students for graduate work in the geosciences, and attracting STEM students into the geosciences. Student presenters will discuss their experiences gained through the field school and give their impressions about how the program works towards the goal of increasing diversity in the geosciences in the U.S.
Recommended reference figures for geophysics and geodesy
NASA Technical Reports Server (NTRS)
Khan, M. A.; Okeefe, J. A.
1973-01-01
Specific reference figures are recommended for consistent use in geophysics and geodesy. The selection of appropriate reference figure for geophysical studies suggests a relationship between the Antarctic negative gravity anomaly and the great shrinkage of the Antarctic ice cap about 4-5 million years ago. The depression of the south polar regions relative to the north polar regions makes the Southern Hemisphere flatter than the Northern Hemisphere, thus producing the third harmonic (pear-shaped) contribution to the earth's figure.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Svendsen, K.L.; Jordan, J.N.
1982-03-01
Submitted by the United States Member of the Commission on Geophysics of the Panamerican Institute of Geography and History, a specialized agency of the Organization of the American States, this report contains information on some of the United States activities of interest to the Commission and its committees. The specific fields included are: seismology, gravity, geomagnetism, geophysical exploration, volcanology, geothermics, solar-terrestrial physics and oceans and atmospheres.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Svendson, K.L.; Jordan, J.N.
1982-03-01
This report was submitted by the United States Member of the Commission on Geophysics of the Panamerican Institute of Geography and History, a specialized agency of the Organization of the American States. It contains information on some of the United States activities of interest to the Commission and its committees. The specific fields included are: seismology, gravity, geomagnetism, geophysical exploration, volcanology, geothermics, solar terrestrial physics and oceans and atmospheres.
2015-09-24
engineering field, or equivalent experience, and are familiar with the basic MR processes. Section 2 summarizes the physical justification for the... Engineering Problems (SAGEEP), Seattle, April 2 -6, 2006. 8. Interstate Technology and Regulatory Council. 2004. “Geophysical Prove-Outs for Munitions Response...YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD-MM-YYYY) 2 . REPORT TYPE 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER
2015-09-24
engineering field, or equivalent experience, and are familiar with the basic MR processes. Section 2 summarizes the physical justification for the... Engineering Problems (SAGEEP), Seattle, April 2 -6, 2006. 8. Interstate Technology and Regulatory Council. 2004. “Geophysical Prove-Outs for Munitions Response...YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD-MM-YYYY) 2 . REPORT TYPE 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER
The Global Geophysical Fluids Center of IERS (and its Special Bureau for Mantle)
NASA Astrophysics Data System (ADS)
Chao, B. F.
2002-12-01
The Global Geophysical Fluids Center (GGFC) was established by the International Earth Rotation Service (IERS) on IERS's 10th anniversary day January 1, 1998, in an effort to expand IERS's services to the scientific community. Under the GGFC, eight Special Bureaus (SB) have been selected, each to be responsible for research and data service activities pertaining to mass transports and related geophysical processes in specific components of the Earth system, or "global geophysical fluids," including the atmosphere, oceans, solid Earth, core, and geophysical processes of gravity, loading, tides and hydrological cycles. GGFC and the SBs have the responsibility of supporting, facilitating, and providing services to the worldwide research community, in areas related to the variations in Earth rotation, gravity field and geocenter that are caused by mass transport in the global geophysical fluids. These minute variations have been observed by various space geodetic techniques, as effective remote sensing tools, with ever increasing precision/accuracy and temporal/spatial resolution. The GGFC and SBs have organized dedicated workshops and special sessions at international conferences, published articles, and held regular business meetings. The SBs maintain individual website for data services and information exchanges. See URL bowie.gsfc.nasa.gov/ggfc/. In particular, the SB for Mantle focuses on large-scale mass redistributions that occur in the mantle in association with various dynamic processes, including seismic activities, the post-glacial rebound, and mantle convections.
Conger, Randall W.
1997-01-01
Between April 23, 1996, and June 21, 1996, the U.S. Environmental Protection Agency contracted Haliburton-NUS, Inc., to drill four clusters of three monitoring wells near the Keystone Sanitation Superfund Site. The purpose of the wells is to allow monitoring and sampling of shallow, intermediate, and deep waterbearing zones for the purpose of determining the horizontal and vertical distribution of any contaminated ground water migrating from the Keystone Site. Twelve monitoring wells, ranging in depth from 50 to 397.9 feet below land surface, were drilled in the vicinity of the Keystone Site. The U.S. Geological Survey conducted borehole-geophysical logging and determined, with geophysical logs and other available data, the ideal intervals to be screened in each well. Geophysical logs were run on four intermediate and four deep wells, and a caliper log only was run on shallow well CL-AD-173 (HN-1S). Interpretation of geophysical logs and existing data determined the placement of screens within each borehole.
Physicist + Geologist points to Geophysics Course
ERIC Educational Resources Information Center
Julian, Glenn M.; Stueber, Alan M.
1974-01-01
A two-quarter introductory course in geophysics at the advanced undergraduate/beginning graduate level is described. An outline of course content is provided, and mechanics of instruction are discussed. (DT)
Aeromagnetic surveys in Afghanistan: An updated website for distribution of data
Shenwary, Ghulam Sakhi; Kohistany, Abdul Hakim; Hussain, Sardar; Ashan, Said; Mutty, Abdul Salam; Daud, Mohammad Ahmad; Wussow, Michael D.; Sweeney, Ronald E.; Phillips, Jeffrey D.; Lindsay, Charles R.; Kucks, Robert P.; Finn, Carol A.; Drenth, Benjamin J.; Anderson, Eric D.; Abraham, Jared D.; Liang, Robert T.; Jarvis, James L.; Gardner, Joan M.; Childers, Vicki A.; Ball, David C.; Brozena, John M.
2011-01-01
Because of its geologic setting, Afghanistan has the potential to contain substantial natural resources. Although valuable mineral deposits and petroleum resources have been identified, much of the country's potential remains unknown. Airborne geophysical surveys are a well accepted and cost effective method for obtaining information about the geological setting of an area without the need to be physically located on the ground. Owing to the current security situation and the large areas of the country that have not been evaluated by geophysical exploration methods, a regional airborne geophysical survey was proposed. Acting upon the request of the Islamic Republic of Afghanistan Ministry of Mines, the U.S. Geological Survey contracted with the Naval Research Laboratory to jointly conduct an airborne geophysical and remote sensing survey of Afghanistan.
Geophysical Log Database for the Mississippi Embayment Regional Aquifer Study (MERAS)
Hart, Rheannon M.; Clark, Brian R.
2008-01-01
The Mississippi Embayment Regional Aquifer Study (MERAS) is an investigation of ground-water availability and sustainability within the Mississippi embayment as part of the U.S. Geological Survey Ground-Water Resources Program. The MERAS area consists of approximately 70,000 square miles and encompasses parts of eight states including Alabama, Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee. More than 2,600 geophysical logs of test holes and wells within the MERAS area were compiled into a database and were used to develop a digital hydrogeologic framework from land surface to the top of the Midway Group of upper Paleocene age. The purpose of this report is to document, present, and summarize the geophysical log database, as well as to preserve the geophysical logs in a digital image format for online access.
The use of surface geophysical techniques to detect fractures in bedrock; an annotated bibliography
Lewis, Mark R.; Haeni, F.P.
1987-01-01
This annotated bibliography compiles references about the theory and application of surface geophysical techniques to locate fractures or fracture zones within bedrock units. Forty-three publications are referenced, including journal articles, theses, conference proceedings, abstracts, translations, and reports prepared by private contractors and U.S. Government agencies. Thirty-one of the publications are annotated. The remainder are untranslated foreign language articles, which are listed only as bibliographic references. Most annotations summarize the location, geologic setting, surface geophysical technique used, and results of a study. A few highly relevant theoretical studies are annotated also. Publications that discuss only the use of borehole geophysical techniques to locate fractures are excluded from this bibliography. Also excluded are highly theoretical works that may have little or no known practical application.
Well casing-based geophysical sensor apparatus, system and method
Daily, William D.
2010-03-09
A geophysical sensor apparatus, system, and method for use in, for example, oil well operations, and in particular using a network of sensors emplaced along and outside oil well casings to monitor critical parameters in an oil reservoir and provide geophysical data remote from the wells. Centralizers are affixed to the well casings and the sensors are located in the protective spheres afforded by the centralizers to keep from being damaged during casing emplacement. In this manner, geophysical data may be detected of a sub-surface volume, e.g. an oil reservoir, and transmitted for analysis. Preferably, data from multiple sensor types, such as ERT and seismic data are combined to provide real time knowledge of the reservoir and processes such as primary and secondary oil recovery.
Negligible Risk for Epidemics after Geophysical Disasters
Floret, Nathalie; Viel, Jean-François; Mauny, Frédéric; Hoen, Bruno
2006-01-01
After geophysical disasters (i.e., earthquakes, volcanic eruptions, tsunamis), media reports almost always stress the risk for epidemics; whether this risk is genuine has been debated. We analyzed the medical literature and data from humanitarian agencies and the World Health Organization from 1985 to 2004. Of >600 geophysical disasters recorded, we found only 3 reported outbreaks related to these disasters: 1 of measles after the eruption of Pinatubo in Philippines, 1 of coccidioidomycosis after an earthquake in California, and 1 of Plasmodium vivax malaria in Costa Rica related to an earthquake and heavy rainfall. Even though the humanitarian response may play a role in preventing epidemics, our results lend support to the epidemiologic evidence that short-term risk for epidemics after a geophysical disaster is very low. PMID:16704799
Localized Smart-Interpretation
NASA Astrophysics Data System (ADS)
Lundh Gulbrandsen, Mats; Mejer Hansen, Thomas; Bach, Torben; Pallesen, Tom
2014-05-01
The complex task of setting up a geological model consists not only of combining available geological information into a conceptual plausible model, but also requires consistency with availably data, e.g. geophysical data. However, in many cases the direct geological information, e.g borehole samples, are very sparse, so in order to create a geological model, the geologist needs to rely on the geophysical data. The problem is however, that the amount of geophysical data in many cases are so vast that it is practically impossible to integrate all of them in the manual interpretation process. This means that a lot of the information available from the geophysical surveys are unexploited, which is a problem, due to the fact that the resulting geological model does not fulfill its full potential and hence are less trustworthy. We suggest an approach to geological modeling that 1. allow all geophysical data to be considered when building the geological model 2. is fast 3. allow quantification of geological modeling. The method is constructed to build a statistical model, f(d,m), describing the relation between what the geologists interpret, d, and what the geologist knows, m. The para- meter m reflects any available information that can be quantified, such as geophysical data, the result of a geophysical inversion, elevation maps, etc... The parameter d reflects an actual interpretation, such as for example the depth to the base of a ground water reservoir. First we infer a statistical model f(d,m), by examining sets of actual interpretations made by a geological expert, [d1, d2, ...], and the information used to perform the interpretation; [m1, m2, ...]. This makes it possible to quantify how the geological expert performs interpolation through f(d,m). As the geological expert proceeds interpreting, the number of interpreted datapoints from which the statistical model is inferred increases, and therefore the accuracy of the statistical model increases. When a model f(d,m) successfully has been inferred, we are able to simulate how the geological expert would perform an interpretation given some external information m, through f(d|m). We will demonstrate this method applied on geological interpretation and densely sampled airborne electromagnetic data. In short, our goal is to build a statistical model describing how a geological expert performs geological interpretation given some geophysical data. We then wish to use this statistical model to perform semi automatic interpretation, everywhere where such geophysical data exist, in a manner consistent with the choices made by a geological expert. Benefits of such a statistical model are that 1. it provides a quantification of how a geological expert performs interpretation based on available diverse data 2. all available geophysical information can be used 3. it allows much faster interpretation of large data sets.
Tabletop Models for Electrical and Electromagnetic Geophysics.
ERIC Educational Resources Information Center
Young, Charles T.
2002-01-01
Details the use of tabletop models that demonstrate concepts in direct current electrical resistivity, self-potential, and electromagnetic geophysical models. Explains how data profiles of the models are obtained. (DDR)
Integrated geophysical methods for geotechnical subsurface investigations : final report.
DOT National Transportation Integrated Search
2006-01-01
This report summarizes the New Hampshire Department of Transportations (NHDOTs) investigation of : geophysical techniques to supplement conventional test borings and other explorations on transportation projects. : The Departments geotechnic...
Fiber Optic Geophysics Sensor Array
NASA Astrophysics Data System (ADS)
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.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wallach, J.L.
1990-01-01
The design basis seismic ground motion for the nuclear generating stations at Darlington and at Pickering were determined solely through the assessment of previous earthquakes with no geological, or any other geophysical, input. Since then geophysical maps, showing a north-northwest oriented linear feature with some possible associated seismic activity, were examined. This report discusses the impact of these new discoveries on the Darlington and Pickering nuclear generating stations and on the already known geophysical features of the area.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Whitten, C.B.; Sjostrom, K.J.
1991-04-01
Ground-water contaminants were found in ground-water monitoring wells at the existing landfill. More wells to define the horizontal and vertical extent of the contaminant plume are to be installed. Geophysical techniques (electro-magnetic induction, vertical electrical resistivity, and horizontal resistivity profiling) were used to map the extent of the contaminant plume. Using the geophysical, ground-water elevation, and geologic data, five anomalous areas south and east of the landfill were identified as locations for additional ground-water monitoring wells.
Wacker, Michael A.
2010-01-01
Borehole geophysical logs were obtained from selected exploratory coreholes in the vicinity of the Florida Power and Light Company Turkey Point Power Plant. The geophysical logging tools used and logging sequences performed during this project are summarized herein to include borehole logging methods, descriptions of the properties measured, types of data obtained, and calibration information.
Grauch, V.J.S.; Skipp, Gary L.; Thomas, Jonathan V.; Davis, Joshua K.; Benson, Mary Ellen
2015-01-01
BP-3-USGS was sited to test hypotheses developed from geophysical studies and to answer questions about the history and evolution of Pliocene and Pleistocene Lake Alamosa, which is represented by lacustrine deposits sampled by the well. The findings reported here represent a basis from which future studies can answer these questions and address other important scientific questions in the San Luis Valley regarding geologic history and climate change, groundwater hydrology, and geophysical interpretation.
NASA Astrophysics Data System (ADS)
Alekseenko, Victor; Bagrova, Anastasia; Cui, Shuwang; He, Yayun; Li, Bingbing; Ma, Xinhua; Pozdnyakov, Egor; Shchegolev, Oleg; Stenkin, Yuri; Stepanov, Vladimir
2017-06-01
Some exotic geophysical events are observed by a global net of electron-neutron detectors (en-detectors) developed in the framework of the PRISMA EAS project. Our en-detectors running both on the Earth's surface and underground are continuously measuring the environmental thermal neutron flux. Thermal neutrons are in equilibrium with media and are therefore sensitive to many geophysical phenomena, which are exotic for people studying ultra high-energy cosmic rays or carrying out low background experiments deep underground.
Global change research related to the Earth's energy and hydrologic cycle
NASA Technical Reports Server (NTRS)
Perkey, Donald J.
1994-01-01
The following are discussed: Geophysical Modeling and Processes; Land Surface Processes and Atmospheric Interactions; Remote Sensing Technology and Geophysical Retrievals; and Scientific Data Management and Visual Analysis.
Publications - GMC 319 | Alaska Division of Geological & Geophysical
DGGS GMC 319 Publication Details Title: Porotechnology data and cation exchange capacity data Authors and cation exchange capacity data: Alaska Division of Geological & Geophysical Surveys Geologic
Publications - GMC 312 | Alaska Division of Geological & Geophysical
DGGS GMC 312 Publication Details Title: Conventional porosity and permeability data of 24 Cook Inlet Reference Alaska Division of Geological & Geophysical Surveys, 2004, Conventional porosity and
NASA Astrophysics Data System (ADS)
Kruse Christensen, Nikolaj; Ferre, Ty Paul A.; Fiandaca, Gianluca; Christensen, Steen
2017-03-01
We present a workflow for efficient construction and calibration of large-scale groundwater models that includes the integration of airborne electromagnetic (AEM) data and hydrological data. In the first step, the AEM data are inverted to form a 3-D geophysical model. In the second step, the 3-D geophysical model is translated, using a spatially dependent petrophysical relationship, to form a 3-D hydraulic conductivity distribution. The geophysical models and the hydrological data are used to estimate spatially distributed petrophysical shape factors. The shape factors primarily work as translators between resistivity and hydraulic conductivity, but they can also compensate for structural defects in the geophysical model. The method is demonstrated for a synthetic case study with sharp transitions among various types of deposits. Besides demonstrating the methodology, we demonstrate the importance of using geophysical regularization constraints that conform well to the depositional environment. This is done by inverting the AEM data using either smoothness (smooth) constraints or minimum gradient support (sharp) constraints, where the use of sharp constraints conforms best to the environment. The dependency on AEM data quality is also tested by inverting the geophysical model using data corrupted with four different levels of background noise. Subsequently, the geophysical models are used to construct competing groundwater models for which the shape factors are calibrated. The performance of each groundwater model is tested with respect to four types of prediction that are beyond the calibration base: a pumping well's recharge area and groundwater age, respectively, are predicted by applying the same stress as for the hydrologic model calibration; and head and stream discharge are predicted for a different stress situation. As expected, in this case the predictive capability of a groundwater model is better when it is based on a sharp geophysical model instead of a smoothness constraint. This is true for predictions of recharge area, head change, and stream discharge, while we find no improvement for prediction of groundwater age. Furthermore, we show that the model prediction accuracy improves with AEM data quality for predictions of recharge area, head change, and stream discharge, while there appears to be no accuracy improvement for the prediction of groundwater age.
About well-posed definition of geophysical fields'
NASA Astrophysics Data System (ADS)
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 (in an underground half-space) a field measured at the surface, allows you to make the interpretation of geophysical data, to build a cross-section, determine the depth, the approximate shape and size of the sources measured at the surface of the geophysical fields. Appliance of the method are any geophysical surveys: magnetic, gravimetric, electrical exploration, seismic, geochemical surveying, etc. Method was tested on model examples, and practical data. The results are confirmed by drilling.
NASA Astrophysics Data System (ADS)
Janzhura, Alexander
A real-time information on geophysical processes in polar regions is very important for goals of Space Weather monitoring by the ground-based means. The modern communication systems and computer technology makes it possible to collect and process the data from remote sites without significant delays. A new acquisition equipment based on microprocessor modules and reliable in hush climatic conditions was deployed at the Roshydromet networks of geophysical observations in Arctic and is deployed at observatories in Antarctic. A contemporary system for on-line collecting and transmitting the geophysical data from the Arctic and Antarctic stations to AARI has been realized and the Polar Geophysical Center (PGC) arranged at AARI ensures the near-real time processing and analyzing the geophysical information from 11 stations in Arctic and 5 stations in Antarctic. The space weather monitoring by the ground based means is one of the main tasks standing before the Polar Geophysical Center. As studies by Troshichev and Janzhura, [2012] showed, the PC index characterizing the polar cap magnetic activity appeared to be an adequate indicator of the solar wind energy that entered into the magnetosphere and the energy that is accumulating in the magnetosphere. A great advantage of the PC index application over other methods based on satellite data is a permanent on-line availability of information about magnetic activity in both northern and southern polar caps. A special procedure agreed between Arctic and Antarctic Research Institute (AARI) and Space Institute of the Danish Technical University (DTUSpace) ensures calculation of the unified PC index in quasi-real time by magnetic data from the Thule and Vostok stations (see public site: http://pc-index.org). The method for estimation of AL and Dst indices (as indicators of state of the disturbed magnetosphere) based on data on foregoing PC indices has been elaborated and testified in the Polar Geophysical Center. It is demonstrated that the PC index can be successfully used to monitor the state of the magnetosphere (space weather monitoring) and the readiness of the magnetosphere to producing substorm or storm (space weather nowcasting).
Integration of Geophysical and Geochemical Data
NASA Astrophysics Data System (ADS)
Yamagishi, Y.; Suzuki, K.; Tamura, H.; Nagao, H.; Yanaka, H.; Tsuboi, S.
2006-12-01
Integration of geochemical and geophysical data would give us a new insight to the nature of the Earth. It should advance our understanding for the dynamics of the Earth's interior and surface processes. Today various geochemical and geophysical data are available on Internet. These data are stored in various database systems. Each system is isolated and provides own format data. The goal of this study is to display both the geochemical and geophysical data obtained from such databases together visually. We adopt Google Earth as the presentation tool. Google Earth is virtual globe software and is provided free of charge by Google, Inc. Google Earth displays the Earth's surface using satellite images with mean resolution of ~15m. We display any graphical features on Google Earth by KML format file. We have developed softwares to convert geochemical and geophysical data to KML file. First of all, we tried to overlay data from Georoc and PetDB and seismic tomography data on Google Earth. Georoc and PetDB are both online database systems for geochemical data. The data format of Georoc is CSV and that of PetDB is Microsoft Excel. The format of tomography data we used is plain text. The conversion software can process these different file formats. The geochemical data (e. g. compositional abundance) is displayed as a three-dimensional column on the Earth's surface. The shape and color of the column mean the element type. The size and color tone vary according to the abundance of the element. The tomography data can be converted into a KML file for each depth. This overlay plot of geochemical data and tomography data should help us to correlate internal temperature anomalies to geochemical anomalies, which are observed at the surface of the Earth. Our tool can convert any geophysical and geochemical data to a KML as long as the data is associated with longitude and latitude. We are going to support more geophysical data formats. In addition, we are currently trying to obtain scientific insights for the Earth's interior based on the view of both geophysical and geochemical data on Google Earth.
Paillet, Frederick L.; Crowder, R.E.
1996-01-01
Quantitative analysis of geophysical logs in ground-water studies often involves at least as broad a range of applications and variation in lithology as is typically encountered in petroleum exploration, making such logs difficult to calibrate and complicating inversion problem formulation. At the same time, data inversion and analysis depend on inversion model formulation and refinement, so that log interpretation cannot be deferred to a geophysical log specialist unless active involvement with interpretation can be maintained by such an expert over the lifetime of the project. We propose a generalized log-interpretation procedure designed to guide hydrogeologists in the interpretation of geophysical logs, and in the integration of log data into ground-water models that may be systematically refined and improved in an iterative way. The procedure is designed to maximize the effective use of three primary contributions from geophysical logs: (1) The continuous depth scale of the measurements along the well bore; (2) The in situ measurement of lithologic properties and the correlation with hydraulic properties of the formations over a finite sample volume; and (3) Multiple independent measurements that can potentially be inverted for multiple physical or hydraulic properties of interest. The approach is formulated in the context of geophysical inversion theory, and is designed to be interfaced with surface geophysical soundings and conventional hydraulic testing. The step-by-step procedures given in our generalized interpretation and inversion technique are based on both qualitative analysis designed to assist formulation of the interpretation model, and quantitative analysis used to assign numerical values to model parameters. The approach bases a decision as to whether quantitative inversion is statistically warranted by formulating an over-determined inversion. If no such inversion is consistent with the inversion model, quantitative inversion is judged not possible with the given data set. Additional statistical criteria such as the statistical significance of regressions are used to guide the subsequent calibration of geophysical data in terms of hydraulic variables in those situations where quantitative data inversion is considered appropriate.
Archaeogeophysical tests in water saturated and under water scenarios at the Hydrogeosite Laboratory
NASA Astrophysics Data System (ADS)
Capozzoli, Luigi; De Martino, Gregory; Giampaolo, Valeria; Perciante, Felice; Rizzo, Enzo
2016-04-01
The growing interest in underwater archaeology as witnessed by numerous archaeological campaigns carried out in the Mediterranean region in marine and lacustrine environments involves a challenge of great importance for archaeogeophysical discipline. Through a careful use of geophysical techniques it is possible support archaeological research to identify and analyse the undiscovered cultural heritage placed under water located near rivers and sea. Over the past decades, geophysical methods were applied successfully in the field of archaeology: an integrated approach based on the use of electric, electromagnetic and magnetic techniques have showed the ability to individuate and reconstruct the presence of archaeological remains in the subsoil allowing to define their distribution in the space limiting the excavation activities. Moreover the capability of geophysics could be limited cause the low geophysical contrasts occurring between archaeological structures and surrounding environment; in particular problems of resolution, depth of investigation and sensitivity related to each adopted technique can result in a distorted reading of the subsurface behaviour preventing the identification of archaeological remains. This problem is amplified when geophysical approach is applied in very humid environments such as in lacustrine and marine scenarios, or in soils characterized by high clay content that make more difficult the propagation of geophysical signals. In order to improve our geophysical knowledge in lacustrine and coastal scenarios a complex and innovative research project was realized at the CNR laboratory of Hydrogeosite which permitted to perform an archaeogeophysical experiment in controlled conditions. The designed archaeological context was focused on the Roman age and various elements characterized by different shapes and materials were placed at different depths in the sub-soil. The preliminary project activities with some scenarios were presented last year, now we would like to show the final results of the project where different scenarios were set up for GPR and ERT investigations. Severale phases were performed: buried objects were covered by different thickness of sediments and different soil water contents were defined. Moreover, geophysical measurements were acquired on an underwater scenario. The 2D and 3D acquisitions have allowed to identify the limits and the abilities of the GPR and resistivity measurements.
Publications - AR 2008 | Alaska Division of Geological & Geophysical
Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic ; Geophysical Surveys Ordering Info: Download below or please see our publication sales page for more
Publications - AR 2007 | Alaska Division of Geological & Geophysical
Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic ; Geophysical Surveys Ordering Info: Download below or please see our publication sales page for more
Publications - AR 2001 | Alaska Division of Geological & Geophysical
Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic ; Geophysical Surveys Ordering Info: Download below or please see our publication sales page for more
Publications - AR 2002 | Alaska Division of Geological & Geophysical
Publications Search Statewide Maps New Releases Sales Interactive Maps Databases Sections Geologic ; Geophysical Surveys Ordering Info: Download below or please see our publication sales page for more
Publications - GMC 6 | Alaska Division of Geological & Geophysical Surveys
, George Publication Date: 1977 Publisher: Alaska Division of Geological & Geophysical Surveys Total . Bibliographic Reference Marshall, Thomas, and Claypool, George, 1977, Pyrolysis - organic carbon studies for the
Publications - GMC 18 | Alaska Division of Geological & Geophysical Surveys
Authors: Unknown Publication Date: Unknown Publisher: Alaska Division of Geological & Geophysical information. Bibliographic Reference Unknown, [n.d.], Geochemical analysis (total organic carbon, rock-eval
Publications - GMC 166 | Alaska Division of Geological & Geophysical
: Unknown Publication Date: 1990 Publisher: Alaska Division of Geological & Geophysical Surveys Total . Bibliographic Reference Unknown, 1990, Vitrinite reflectance data of cuttings (2400'-8680') and of core (7895
Publications - GMC 46 | Alaska Division of Geological & Geophysical Surveys
wells Authors: Unknown Publication Date: 1984 Publisher: Alaska Division of Geological & Geophysical information. Bibliographic Reference Unknown, 1984, Shale bulk density analysis of cuttings from 10 North
Atmospheric Science Data Center
2013-04-16
... of the region and can be used to understand the geophysical environment. The top panel shows the region from MISR's downward-looking ... angular reflectance properties help explain the geophysical environment. project: MISR category: gallery ...
USDA-ARS?s Scientific Manuscript database
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...
NASA Astrophysics Data System (ADS)
Eppelbaum, Lev
2015-04-01
Geophysical methods are prompt, non-invasive and low-cost tool for quantitative delineation of buried archaeological targets. However, taking into account the complexity of geological-archaeological media, some unfavourable environments and known ambiguity of geophysical data analysis, a single geophysical method examination might be insufficient (Khesin and Eppelbaum, 1997). Besides this, it is well-known that the majority of inverse-problem solutions in geophysics are ill-posed (e.g., Zhdanov, 2002), which means, according to Hadamard (1902), that the solution does not exist, or is not unique, or is not a continuous function of observed geophysical data (when small perturbations in the observations will cause arbitrary mistakes in the solution). This fact has a wide application for informational, probabilistic and wavelet methodologies in archaeological geophysics (Eppelbaum, 2014a). The goal of the modern geophysical data examination is to detect the geophysical signatures of buried targets at noisy areas via the analysis of some physical parameters with a minimal number of false alarms and miss-detections (Eppelbaum et al., 2011; Eppelbaum, 2014b). The proposed wavelet approach to recognition of archaeological targets (AT) by the examination of geophysical method integration consists of advanced processing of each geophysical method and nonconventional integration of different geophysical methods between themselves. The recently developed technique of diffusion clustering combined with the abovementioned wavelet methods was utilized to integrate the geophysical data and detect existing irregularities. The approach is based on the wavelet packet techniques applied as to the geophysical images (or graphs) versus coordinates. For such an analysis may be utilized practically all geophysical methods (magnetic, gravity, seismic, GPR, ERT, self-potential, etc.). On the first stage of the proposed investigation a few tens of typical physical-archaeological models (PAM) (e.g., Eppelbaum et al., 2010; Eppelbaum, 2011) of the targets under study for the concrete area (region) are developed. These PAM are composed on the basis of the known archaeological and geological data, results of previous archaeogeophysical investigations and 3D modeling of geophysical data. It should be underlined that the PAMs must differ (by depth, size, shape and physical properties of AT as well as peculiarities of the host archaeological-geological media). The PAMs must include also noise components of different orders (corresponding to the archaeogeophysical conditions of the area under study). The same models are computed and without the AT. Introducing complex PAMs (for example, situated in the vicinity of electric power lines, some objects of infrastructure, etc. (Eppelbaum et al., 2001)) will reflect some real class of AT occurring in such unfavorable for geophysical searching conditions. Anomalous effects from such complex PAMs will significantly disturb the geophysical anomalies from AT and impede the wavelet methodology employment. At the same time, the 'self-learning' procedure laid in this methodology will help further to recognize the AT even in the cases of unfavorable S/N ratio. Modern developments in the wavelet theory and data mining are utilized for the analysis of the integrated data. Wavelet approach is applied for derivation of enhanced (e.g., coherence portraits) and combined images of geophysical fields. The modern methodologies based on the matching pursuit with wavelet packet dictionaries enables to extract desired signals even from strongly noised data (Averbuch et al., 2014). Researchers usually met the problem of extraction of essential features from available data contaminated by a random noise and by a non-relevant background (Averbuch et al., 2014). If the essential structure of a signal consists of several sine waves then we may represent it via trigonometric basis (Fourier analysis). In this case one can compare the signal with a set of sinusoids and extract consistent ones. An indicator of presence a wave in a signal f(t) is the Fourier coefficient ∫ f(t) sinwt dt. Wavelet analysis provides a rich library of waveforms available and fast, computationally efficient procedures of representation of signals and of selection of relevant waveforms. The basic assumption justifying an application of wavelet analysis is that the essential structure of a signal analyzed consists of not a large number of various waveforms. The best way to reveal this structure is representation of the signal by a set of basic elements containing waveforms coherent to the signal. For structures of the signal coherent to the basis, large coefficients are attributed to a few basic waveforms, whereas we expect small coefficients for the noise and structures incoherent to all basic waveforms. Wavelets are a family of functions ranging from functions of arbitrary smoothness to fractal ones. Wavelet procedure involves two aspects. The first one is a decomposition, i.e. breaking up a signal to obtain the wavelet coefficients and the 2nd one is a reconstruction, which consists of a reassembling the signal from coefficients There are many modifications of the WA. Note, first of all, so-called Continuous WA in whichsignal f(t) is tested for presence of waveforms ψ(t-b) a. Here, a is scaling parameter (dilation), bdetermines location of the wavelet ψ(t-b) a in a signal f(t). The integral ( ) ∫ t-b (W ψf) (b,a) = f (t) ψ a dt is the Continuous Wavelet Transform.When parameters a,b in ψ( ) t-ab take some discrete values, we have the Discrete Wavelet Transform. A general scheme of the Wavelet Decomposition Tree is shown, for instance, in (Averbuch et al., 2014; Eppelbaum et al., 2014). The signal is compared with the testing signal on each scale. It is estimated wavelet coefficients which enable to reconstruct the 1st approximation of the signal and details. On the next level, wavelet transform is applied to the approximation. Then, we can present A1 as A2 + D2, etc. So, if S - Signal, A - Approximation, D - Details, then S = A1 + D1 = A2 + D2 + D1 = A3 + D3 + D2 + D1. Wavelet packet transform is applied to both low pass results (approximations) and high pass results (Details). For analyzing the geophysical data, we used a technique based on the algorithm to characterize a geophysical image by a limited number of parameters (Eppelbaum et al., 2012). This set of parameters serves as a signature of the image and is utilized for discrimination of images (a) containing AT from the images (b) non-containing AT (let will designate these images as N). The constructed algorithm consists of the following main phases: (a) collection of the database, (b) characterization of geophysical images, (c) and dimensionality reduction. Then, each image is characterized by the histogram of the coherency directions (Alperovich et al., 2013). As a result of the previous steps we obtain two sets: containing AT and N of the signatures vectors for geophysical images. The obtained 3D set of the data representatives can be used as a reference set for the classification of newly arriving geophysical data. The obtained data sets are reduced by embedding features vectors into the 3D Euclidean space using the so-called diffusion map. This map enables to reveal the internal structure of the datasets AT and N and to distinctly separate them. For this, a matrix of the diffusion distances for the combined feature matrix F = FN ∴ FC of size 60 x C is constructed (Coifman and Lafon, 2006; Averbuch et al., 2010). Then, each row of the matrices FN and FC is projected onto three first eigenvectors of the matrix D(F ). As a result, each data curve is represented by a 3D point in the Euclidean space formed by eigenvectors of D(F ). The Euclidean distances between these 3D points reflect the similarity of the data curves. The scattered projections of the data curves onto the diffusion eigenvectors will be composed. Finally we 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. of the 2011 SAGEEP Conference, Charleston, South Carolina, USA, 24, 24-60. Eppelbaum, L.V., Khesin, B.E. and Itkis, S.E., 2001. Prompt magnetic investigations of archaeological remains in areas of infrastructure development: Israeli experience. Archaeological Prospection, 8, No.3, 163-185. Eppelbaum, L.V., Khesin, B.E. and Itkis, S.E., 2010. Archaeological geophysics in arid environments: Examples from Israel. Journal of Arid Environments, 74, No. 7, 849-860. Eppelbaum, L.V., Zheludev, V. and Averbuch, A., 2014. Diffusion maps as a powerful tool for integrated geophysical field analysis to detecting hidden karst terranes. Izv. Acad. Sci. Azerb. Rep., Ser.: Earth Sciences, No. 1-2, 36-46. Hadamard, J., 1902. Sur les problèmes aux dérivées partielles et leur signification physique. Princeton University Bulletin, 13, 49-52. Khesin, B.E. and Eppelbaum, L.V., 1997. The number of geophysical methods required for target classification: quantitative estimation. Geoinformatics, 8, No.1, 31-39. Zhdanov, M.S., 2002. Geophysical Inverse Theory and Regularization Problems. Methods in Geochemistry and Geophysics, Vol. 36. Elsevier, Amsterdam.
Publications - GMC 71 | Alaska Division of Geological & Geophysical Surveys
DGGS GMC 71 Publication Details Title: Visual kerogens and rock evaluation pyrolysis determinations for evaluation pyrolysis determinations for 16 North Slope wells: Alaska Division of Geological & Geophysical
Staff - Gina Graham | Alaska Division of Geological & Geophysical Surveys
Gina Graham Gina Graham Position: Geologist, Mineral Resources Address: 3354 College Road Fairbanks, AK Resources, Division of Geological & Geophysical Surveys (DGGS) 3354 College Road, Fairbanks, AK 99709
Publications - GMC 131 | Alaska Division of Geological & Geophysical
and core from the Chevron USA Inc. Eagle Creek #1 well Authors: Unknown Publication Date: 1989 Inc. Eagle Creek #1 well: Alaska Division of Geological & Geophysical Surveys Geologic Materials
Publications - GMC 371 | Alaska Division of Geological & Geophysical
Property under Northwest Explorations joint venture ownership - (1970 to 2005) and plan of operation (2006 - (1970 to 2005) and plan of operation (2006): Alaska Division of Geological & Geophysical Surveys
Staff - Shelly L. Showalter | Alaska Division of Geological & Geophysical
Facebook DGGS News Natural Resources Geological & Geophysical Surveys Staff - Shelly L. Showalter main content Shelly L. Showalter Shelly L. Showalter Responsible for budget development, accounting, and
Triad Issue Paper: Using Geophysical Tools to Develop the Conceptual Site Model
This technology bulletin explains how hazardous-waste site professionals can use geophysical tools to provide information about subsurface conditions to create a more representative conceptual site model (CSM).
Publications - IC 44 ed. 2004 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Map; Aeromagnetic Survey; Airborne Geophysical Survey; Alaska, State of; Bibliography; Coastal and
Publications - GMC 87 | Alaska Division of Geological & Geophysical Surveys
: Unknown Publication Date: 1988 Publisher: Alaska Division of Geological & Geophysical Surveys Total . Bibliographic Reference Unknown, 1988, Capillary pressure test data for 14 North Slope wells: Alaska Division of
Publications - IC 35 | Alaska Division of Geological & Geophysical Surveys
DGGS IC 35 Publication Details Title: Alaska's mineral industry 1991: A summary Authors: Bundtzen, T.K ., 1992, Alaska's mineral industry 1991: A summary: Alaska Division of Geological & Geophysical
Publications - IC 36 | Alaska Division of Geological & Geophysical Surveys
DGGS IC 36 Publication Details Title: Alaska's mineral industry 1992: A summary Authors: Swainbank, R.C ., 1993, Alaska's mineral industry 1992: A summary: Alaska Division of Geological & Geophysical
Publications - PDF 88-8 | Alaska Division of Geological & Geophysical
content DGGS PDF 88-8 Publication Details Title: Alaska's mineral industry 1987: Executive summary Authors , Alaska's mineral industry 1987: Executive summary: Alaska Division of Geological & Geophysical Surveys
Publications - IC 40 | Alaska Division of Geological & Geophysical Surveys
DGGS IC 40 Publication Details Title: Alaska's mineral industry 1994: A summary Authors: Swainbank, R.C mineral industry 1994: A summary: Alaska Division of Geological & Geophysical Surveys Information
Publications - GMC 339 | Alaska Division of Geological & Geophysical
petrography from petrographic thin sections of core (4759'-4894') Authors: Unknown Publication Date: Feb 2007 thin sections of core (4759'-4894'): Alaska Division of Geological & Geophysical Surveys Geologic
Atmospheric Science Data Center
2013-09-05
... of creating stable, community accepted Earth System Data Records (ESDRs) for a variety of geophysical time series. A reanalysis and ... of creating stable, community accepted Earth System Data Records (ESDRs) for a variety of geophysical time series. A reanalysis and ...
Publications - GMC 152 | Alaska Division of Geological & Geophysical
') from the Alaska Consolidated Oil Iniskin Unit Beal #1 well Authors: Unknown Publication Date: 1990 Consolidated Oil Iniskin Unit Beal #1 well: Alaska Division of Geological & Geophysical Surveys Geologic
Geophysical assessment of karst activity
DOT National Transportation Integrated Search
2008-02-01
MST proposes to acquire electrical resistivity data within a pipeline/roadway ROW. These geophysical data will be processed, analyzed and interpreted with the objective of locating and mapping any subsurface voids that might compromise the integrity ...
Phelps, Geoffrey A.; Ippolito, C.; Lee, R.; Spritzer, R.; Yeh, Y.
2014-01-01
The U.S. Geological Survey and the National Aeronautics and Space Administration are cooperatively investigating the utility of unmanned vehicles for near-real-time autonomous surveys of geophysical data collection. Initially focused on unmanned ground vehicle collection of magnetic data, this cooperative effort has brought unmanned surveying, precision guidance, near-real-time communication, on-the-fly data processing, and near-real-time data interpretation into the realm of ground geophysical surveying, all of which offer advantages over current methods of manned collection of ground magnetic data. An unmanned ground vehicle mission has demonstrated that these vehicles can successfully complete missions to collect geophysical data, and add advantages in data collection, processing, and interpretation. We view the current experiment as an initial phase in further unmanned vehicle data-collection missions, including aerial surveying.
Zhdanov,; Michael, S [Salt Lake City, UT
2008-01-29
Mineral exploration needs a reliable method to distinguish between uneconomic mineral deposits and economic mineralization. A method and system includes a geophysical technique for subsurface material characterization, mineral exploration and mineral discrimination. The technique introduced in this invention detects induced polarization effects in electromagnetic data and uses remote geophysical observations to determine the parameters of an effective conductivity relaxation model using a composite analytical multi-phase model of the rock formations. The conductivity relaxation model and analytical model can be used to determine parameters related by analytical expressions to the physical characteristics of the microstructure of the rocks and minerals. These parameters are ultimately used for the discrimination of different components in underground formations, and in this way provide an ability to distinguish between uneconomic mineral deposits and zones of economic mineralization using geophysical remote sensing technology.
NASA Astrophysics Data System (ADS)
Yegireddi, Satyanarayana; Uday Bhaskar, G.
2009-01-01
Different parameters obtained through well-logging geophysical sensors such as SP, resistivity, gamma-gamma, neutron, natural gamma and acoustic, help in identification of strata and estimation of the physical, electrical and acoustical properties of the subsurface lithology. Strong and conspicuous changes in some of the log parameters associated with any particular stratigraphy formation, are function of its composition, physical properties and help in classification. However some substrata show moderate values in respective log parameters and make difficult to identify or assess the type of strata, if we go by the standard variability ranges of any log parameters and visual inspection. The complexity increases further with more number of sensors involved. An attempt is made to identify the type of stratigraphy from borehole geophysical log data using a combined approach of neural networks and fuzzy logic, known as Adaptive Neuro-Fuzzy Inference System. A model is built based on a few data sets (geophysical logs) of known stratigraphy of in coal areas of Kothagudem, Godavari basin and further the network model is used as test model to infer the lithology of a borehole from their geophysical logs, not used in simulation. The results are very encouraging and the model is able to decipher even thin cola seams and other strata from borehole geophysical logs. The model can be further modified to assess the physical properties of the strata, if the corresponding ground truth is made available for simulation.
Challenges in Extracting Information From Large Hydrogeophysical-monitoring Datasets
NASA Astrophysics Data System (ADS)
Day-Lewis, F. D.; Slater, L. D.; Johnson, T.
2012-12-01
Over the last decade, new automated geophysical data-acquisition systems have enabled collection of increasingly large and information-rich geophysical datasets. Concurrent advances in field instrumentation, web services, and high-performance computing have made real-time processing, inversion, and visualization of large three-dimensional tomographic datasets practical. Geophysical-monitoring datasets have provided high-resolution insights into diverse hydrologic processes including groundwater/surface-water exchange, infiltration, solute transport, and bioremediation. Despite the high information content of such datasets, extraction of quantitative or diagnostic hydrologic information is challenging. Visual inspection and interpretation for specific hydrologic processes is difficult for datasets that are large, complex, and (or) affected by forcings (e.g., seasonal variations) unrelated to the target hydrologic process. New strategies are needed to identify salient features in spatially distributed time-series data and to relate temporal changes in geophysical properties to hydrologic processes of interest while effectively filtering unrelated changes. Here, we review recent work using time-series and digital-signal-processing approaches in hydrogeophysics. Examples include applications of cross-correlation, spectral, and time-frequency (e.g., wavelet and Stockwell transforms) approaches to (1) identify salient features in large geophysical time series; (2) examine correlation or coherence between geophysical and hydrologic signals, even in the presence of non-stationarity; and (3) condense large datasets while preserving information of interest. Examples demonstrate analysis of large time-lapse electrical tomography and fiber-optic temperature datasets to extract information about groundwater/surface-water exchange and contaminant transport.
Coupled geophysical-hydrological modeling of controlled NAPL spill
NASA Astrophysics Data System (ADS)
Kowalsky, M. B.; Majer, E.; Peterson, J. E.; Finsterle, S.; Mazzella, A.
2006-12-01
Past studies have shown reasonable sensitivity of geophysical data for detecting or monitoring the movement of non-aqueous phase liquids (NAPLs) in the subsurface. However, heterogeneity in subsurface properties and in NAPL distribution commonly results in non-unique data interpretation. Combining multiple geophysical data types and incorporating constraints from hydrological models will potentially decrease the non-uniqueness in data interpretation and aid in site characterization. Large-scale laboratory experiments have been conducted over several years to evaluate the use of various geophysical methods, including ground-penetrating radar (GPR), seismic, and electrical methods, for monitoring controlled spills of tetrachloroethylene (PCE), a hazardous industrial solvent that is pervasive in the subsurface. In the current study, we consider an experiment in which PCE was introduced into a large tank containing a heterogeneous distribution of sand and clay mixtures, and allowed to migrate while time-lapse geophysical data were collected. We consider two approaches for interpreting the surface GPR and crosswell seismic data. The first approach involves (a) waveform inversion of the surface GPR data using a non-gradient based optimization algorithm to estimate the dielectric constant distributions and (b) conversion of crosswell seismic travel times to acoustic velocity distributions; the dielectric constant and acoustic velocity distributions are then related to NAPL saturation using appropriate petrophysical models. The second approach takes advantage of a recently developed framework for coupled hydrological-geophysical modeling, providing a hydrological constraint on interpretation of the geophysical data and additionally resulting in quantitative estimates of the most relevant hydrological parameters that determine NAPL behavior in the system. Specifically, we simulate NAPL migration using the multiphase multicomponent flow simulator TOUGH2 with a 2-D radial model that takes advantage of radial symmetry in the experimental setup. The flow model is coupled to forward models for simulating the GPR and seismic measurements, and joint inversion of the multiple data types results in images of time-varying NAPL saturation distributions. Comparison of the two approaches with results of the post-experiment excavation indicate that combining geophysical data types and incorporating hydrological constraints improves estimates of NAPL saturation relative to the conventional interpretation of the geophysical data sets. Notice: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect the official Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation by EPA for use. This work was supported, in part, by the U.S. Dept. of Energy under Contract No. DE-AC02- 05CH11231.
Multivariate time series clustering on geophysical data recorded at Mt. Etna from 1996 to 2003
NASA Astrophysics Data System (ADS)
Di Salvo, Roberto; Montalto, Placido; Nunnari, Giuseppe; Neri, Marco; Puglisi, Giuseppe
2013-02-01
Time series clustering is an important task in data analysis issues in order to extract implicit, previously unknown, and potentially useful information from a large collection of data. Finding useful similar trends in multivariate time series represents a challenge in several areas including geophysics environment research. While traditional time series analysis methods deal only with univariate time series, multivariate time series analysis is a more suitable approach in the field of research where different kinds of data are available. Moreover, the conventional time series clustering techniques do not provide desired results for geophysical datasets due to the huge amount of data whose sampling rate is different according to the nature of signal. In this paper, a novel approach concerning geophysical multivariate time series clustering is proposed using dynamic time series segmentation and Self Organizing Maps techniques. This method allows finding coupling among trends of different geophysical data recorded from monitoring networks at Mt. Etna spanning from 1996 to 2003, when the transition from summit eruptions to flank eruptions occurred. This information can be used to carry out a more careful evaluation of the state of volcano and to define potential hazard assessment at Mt. Etna.
Airborne geophysical surveys conducted in western Nebraska, 2010: contractor reports and data
,
2014-01-01
This report contains three contractor reports and data files for an airborne electromagnetic survey flown from June 28 to July 7, 2010. The first report; “SkyTEM Survey: Nebraska, USA, Data” describes data aquisition and processing from a time-domain electromagnetic and magnetic survey performed by SkyTEM Canada, Inc. (the North American SkyTEM subsidiary), in western Nebraska, USA. Digital data for this report are given in Appendix 1. The airborne geophysical data from the SkyTEM survey subsequently were processed and inverted by Aarhus Geophysics ApS, Aarhus, Denmark, to produce resistivity depth sections along each flight line. The result of that processing is described in two reports presented in Appendix 2, “Processing and inversion of SkyTEM data from USGS Area UTM–13” and “Processing and inversion of SkyTEM data from USGS Area UTM–14.” Funding for these surveys was provided by the North Platte Natural Resources District, the South Platte Natural Resources District, and the Twin Platte Natural Resources District, in Scottsbluff, Sidney, and North Platte, Nebraska, respectively. Any additional information concerning the geophysical data may be obtained from the U.S. Geological Survey Crustal Geophysics and Geochemistry Science Center, Denver Colorado.
Publications - GMC 39 | Alaska Division of Geological & Geophysical Surveys
the Pan Am David River #1-A Authors: Unknown Publication Date: 1982 Publisher: Alaska Division of Geological & Geophysical Surveys Comments: Publication date is estimated. Total Price: $3.00 Ordering
Staff - Scott W. Crass | Alaska Division of Geological & Geophysical
Position: Analyst/Programmer, Volcanology Address: 3354 College Road Fairbanks, AK 99709-3707 Phone: (907 Geological & Geophysical Surveys (DGGS) 3354 College Road, Fairbanks, AK 99709 Phone: (907) 451-5000 Fax
Publications - GMC 189 | Alaska Division of Geological & Geophysical
DGGS GMC 189 Publication Details Title: Apatite and zircon fission track analyses of 9 selected wells analyses of 9 selected wells in the NPRA, Alaska: Alaska Division of Geological & Geophysical Surveys
GRAIL at Mercury: Coherent Laser Tracking for Geophysics
NASA Astrophysics Data System (ADS)
Mazarico, E.; Goossens, S.; Genova, A.; Sun, X.; Yang, G.
2018-05-01
We present an instrument concept for satellite-to-satellite tracking at optical wavelength to measure the gravity field of Mercury with sufficient accuracy and resolution to significantly advance our understanding of its geophysical evolution.
Assessment of geophysical flows for zero-gravity simulation
NASA Technical Reports Server (NTRS)
Winn, C. B.; Cox, A.; Srivatsangam, R.
1976-01-01
The results of research relating to the feasibility of using a low gravity environment to model geophysical flows are presented. Atmospheric and solid earth flows are considered. Possible experiments and their required apparatus are suggested.
Tools for proximal soil sensing
USDA-ARS?s Scientific Manuscript database
Proximal soil sensing (i.e. near-surface geophysical methods) are used to study soil phenomena across spatial scales. Geophysical methods exploit contrasts in physical properties (dielectric permittivity, apparent electrical conductivity or resistivity, magnetic susceptibility) to indirectly measur...
Publications - GMC 229 | Alaska Division of Geological & Geophysical
core (6,144-6,419') from the Texaco Inc. Colville Delta #2 well Authors: Unknown Publication Date: 1994 Texaco Inc. Colville Delta #2 well: Alaska Division of Geological & Geophysical Surveys Geologic
Publications - GMC 227 | Alaska Division of Geological & Geophysical
core (5,127-6,481') from the Texaco Inc. Colville Delta #3 Authors: Unknown Publication Date: 1994 Texaco Inc. Colville Delta #3: Alaska Division of Geological & Geophysical Surveys Geologic Materials
Publications - GMC 223 | Alaska Division of Geological & Geophysical
core (7,880-8,750') of the Texaco Oil Colville Delta #1 well Authors: Unknown Publication Date: 1994 Texaco Oil Colville Delta #1 well: Alaska Division of Geological & Geophysical Surveys Geologic
Publications - PDF 89-7 | Alaska Division of Geological & Geophysical
content DGGS PDF 89-7 Publication Details Title: Summary of Alaska's mineral industry in 1988 Authors , Summary of Alaska's mineral industry in 1988: Alaska Division of Geological & Geophysical Surveys
Publications - IC 39 | Alaska Division of Geological & Geophysical Surveys
DGGS IC 39 Publication Details Title: Alaska's mineral industry 1993: A summary Authors: Bundtzen, T.K 1993: A summary: Alaska Division of Geological & Geophysical Surveys Information Circular 39, 11 p
Publications - IC 58 | Alaska Division of Geological & Geophysical Surveys
DGGS IC 58 Publication Details Title: Alaska's mineral industry 2008: A summary Authors: Szumigala, D.J summary: Alaska Division of Geological & Geophysical Surveys Information Circular 58, 15 p. http
Publications - IC 41 | Alaska Division of Geological & Geophysical Surveys
DGGS IC 41 Publication Details Title: Alaska's mineral industry 1995: A summary Authors: Bundtzen, T.K 1995: A summary: Alaska Division of Geological & Geophysical Surveys Information Circular 41, 12 p
Publications - PDF 90-10 | Alaska Division of Geological & Geophysical
content DGGS PDF 90-10 Publication Details Title: Summary of Alaska's mineral industry in 1989 Authors , Summary of Alaska's mineral industry in 1989: Alaska Division of Geological & Geophysical Surveys
Publications - GMC 378 | Alaska Division of Geological & Geophysical
DGGS GMC 378 Publication Details Title: 1967 report on the induced polarization and resistivity survey Bibliographic Reference McPhar Geophysics Limited, 2010, 1967 report on the induced polarization and resistivity
Staff - Kurt J. Johnson | Alaska Division of Geological & Geophysical
Facebook DGGS News Natural Resources Geological & Geophysical Surveys Staff - Kurt J. Johnson main content Kurt J. Johnson Kurt J. Johnson Position: Geologist, Geologic Materials Center Address: 3651
Publications - DDS 4 | Alaska Division of Geological & Geophysical Surveys
Datasets of Alaska: Alaska Division of Geological & Geophysical Surveys Digital Data Series 4, http ; Alaska Statewide Maps; Alaska, State of; Digital Elevation Model; Digital Surface Model (DSM); Geologic
Publications - GMC 259 | Alaska Division of Geological & Geophysical
core (6,467-6,515.8') from the Exxon Corporation Thetis Island #1 well Authors: Unknown Publication ') from the Exxon Corporation Thetis Island #1 well: Alaska Division of Geological & Geophysical
Publications - GMC 377 | Alaska Division of Geological & Geophysical
Quadrangle, Alaska: 1977-1980 Drill holes (Drill Logs and Assay Records) Authors: U.S. Borax Publication Date : 1977-1980 Drill holes (Drill Logs and Assay Records): Alaska Division of Geological & Geophysical
Identification of the Polaris Fault using lidar and shallow geophysical methods
Hunter, Lewis E.; Powers, Michael H.; Burton, Bethany L.
2017-01-01
As part of the U.S. Army Corps of Engineers' (USACE) Dam Safety Assurance Program, Martis Creek Dam near Truckee, CA, is under evaluation for earthquake and seepage hazards. The investigations to date have included LiDAR (Light Detection and Ranging) and a wide range of geophysical surveys. The LiDAR data led to the discovery of an important and previously unknown fault tracing very near and possibly under Martis Creek Dam. The geophysical surveys of the dam foundation area confirm evidence of the fault in the area.
The discovery and geophysical response of the Atlántida Cu-Au porphyry deposit, Chile
NASA Astrophysics Data System (ADS)
Hope, Matthew; Andersson, Steve
2016-03-01
The discovery of the Atlántida Cu-Au-Mo porphyry deposit, which is unconformably overlain by 25-80 m of gravels, is a recent example of exploration success under cover in a traditional mining jurisdiction. Early acquisition of geophysics was a key tool in the discovery, and in later guiding further exploration drilling throughout the life of the project. Detailed review of the geophysical response of the deposit, with respect to the distribution of lithologies and alteration, coupled with their petrophysical properties has allowed full characterisation, despite no exposure at the surface of host rock nor porphyry-style mineralisation. Data acquired over the project include induced polarisation, magnetotellurics, ground and airborne magnetics, ground-based gravimetry, and petrophysical sampling. The distribution of the key geological features of the deposit has been inferred via acquisition of petrophysical properties and interpretation of surface geophysical datasets. Magnetic susceptibility is influenced strongly by both alteration and primary lithology, whilst density variations are dominated by primary lithological control. Several studies have shown that electrical properties may map the footprint of the hydrothermal system and associated mineralisation, via a combination of chargeability and resistivity. These properties are observed in geophysical datasets acquired at surface and allow further targeting and sterilisation at the deposit and project scale. By understanding these geophysical characteristics in a geological context, these data can be used to infer distribution of lithological units, depth to exploration targets and the potential for high grade mineralisation. Future exploration will likely be increasingly reliant on the understanding of the surface manifestations of buried deposits in remotely acquired data. This review summarises the application and results of these principles at the Atlántida project of northern Chile. Geophysical data can be used to improve the chances of discovery beneath post-mineral cover, and also improve drilling results throughout the advanced exploration of the program. The process of data review against geological control information is essential.
Karst aquifer characterization using geophysical remote sensing of dynamic recharge events
NASA Astrophysics Data System (ADS)
Grapenthin, R.; Bilek, S. L.; Luhmann, A. J.
2017-12-01
Geophysical monitoring techniques, long used to make significant advances in a wide range of deeper Earth science disciplines, are now being employed to track surficial processes such as landslide, glacier, and river flow. Karst aquifers are another important hydrologic resource that can benefit from geophysical remote sensing, as this monitoring allows for safe, noninvasive karst conduit measurements. Conduit networks are typically poorly constrained, let alone the processes that occur within them. Geophysical monitoring can also provide a regionally integrated analysis to characterize subsurface architecture and to understand the dynamics of flow and recharge processes in karst aquifers. Geophysical signals are likely produced by several processes during recharge events in karst aquifers. For example, pressure pulses occur when water enters conduits that are full of water, and experiments suggest seismic signals result from this process. Furthermore, increasing water pressure in conduits during recharge events increases the load applied to conduit walls, which deforms the surrounding rock to yield measureable surface displacements. Measureable deformation should also occur with mass loading, with subsidence and rebound signals associated with increases and decreases of water mass stored in the aquifer, respectively. Additionally, geophysical signals will likely arise with turbulent flow and pore pressure change in the rock surrounding conduits. Here we present seismic data collected during a pilot study of controlled and natural recharge events in a karst aquifer system near Bear Spring, near Eyota, MN, USA as well as preliminary model results regarding the processes described above. In addition, we will discuss an upcoming field campaign where we will use seismometers, tiltmeters, and GPS instruments to monitor for recharge-induced responses in a FL, USA karst system with existing cave maps, coupling these geophysical observations with hydrologic and meteorologic data to map and characterize conduits and other features of the larger karst system and to monitor subsurface flow dynamics during recharge events.
Geophysics Under Pressure: Large-Volume Presses Versus the Diamond-Anvil Cell
NASA Astrophysics Data System (ADS)
Hazen, R. M.
2002-05-01
Prior to 1970, the legacy of Harvard physicist Percy Bridgman dominated high-pressure geophysics. Massive presses with large-volume devices, including piston-cylinder, opposed-anvil, and multi-anvil configurations, were widely used in both science and industry to achieve a range of crustal and upper mantle temperatures and pressures. George Kennedy of UCLA was a particularly influential advocate of large-volume apparatus for geophysical research prior to his death in 1980. The high-pressure scene began to change in 1959 with the invention of the diamond-anvil cell, which was designed simultaneously and independently by John Jamieson at the University of Chicago and Alvin Van Valkenburg at the National Bureau of Standards in Washington, DC. The compact, inexpensive diamond cell achieved record static pressures and had the advantage of optical access to the high-pressure environment. Nevertheless, members of the geophysical community, who favored the substantial sample volumes, geothermally relevant temperature range, and satisfying bulk of large-volume presses, initially viewed the diamond cell with indifference or even contempt. Several factors led to a gradual shift in emphasis from large-volume presses to diamond-anvil cells in geophysical research during the 1960s and 1970s. These factors include (1) their relatively low cost at time of fiscal restraint, (2) Alvin Van Valkenburg's new position as a Program Director at the National Science Foundation in 1964 (when George Kennedy's proposal for a Nation High-Pressure Laboratory was rejected), (3) the development of lasers and micro-analytical spectroscopic techniques suitable for analyzing samples in a diamond cell, and (4) the attainment of record pressures (e.g., 100 GPa in 1975 by Mao and Bell at the Geophysical Laboratory). Today, a more balanced collaborative approach has been adopted by the geophysics and mineral physics community. Many high-pressure laboratories operate a new generation of less expensive large-volume presses side-by-side with a wide variety of diamond-anvil cells.
NASA Astrophysics Data System (ADS)
Slater, L. D.; Robinson, J.; Weller, A.; Keating, K.; Robinson, T.; Parker, B. L.
2017-12-01
Geophysical length scales determined from complex conductivity (CC) measurements can be used to estimate permeability k when the electrical formation factor F describing the ratio between tortuosity and porosity is known. Two geophysical length scales have been proposed: [1] the imaginary conductivity σ" normalized by the specific polarizability cp; [2] the time constant τ multiplied by a diffusion coefficient D+. The parameters cp and D+ account for the control of fluid chemistry and/or varying minerology on the geophysical length scale. We evaluated the predictive capability of two recently presented CC permeability models: [1] an empirical formulation based on σ"; [2] a mechanistic formulation based on τ;. The performance of the CC models was evaluated against measured permeability; this performance was also compared against that of well-established k estimation equations that use geometric length scales to represent the pore scale properties controlling fluid flow. Both CC models predict permeability within one order of magnitude for a database of 58 sandstone samples, with the exception of those samples characterized by high pore volume normalized surface area Spor and more complex mineralogy including significant dolomite. Variations in cp and D+ likely contribute to the poor performance of the models for these high Spor samples. The ultimate value of such geophysical models for permeability prediction lies in their application to field scale geophysical datasets. Two observations favor the implementation of the σ" based model over the τ based model for field-scale estimation: [1] the limited range of variation in cp relative to D+; [2] σ" is readily measured using field geophysical instrumentation (at a single frequency) whereas τ requires broadband spectral measurements that are extremely challenging and time consuming to accurately measure in the field. However, the need for a reliable estimate of F remains a major obstacle to the field-scale implementation of either of the CC permeability models for k estimation.
Practices to enable the geophysical research spectrum: from fundamentals to applications
NASA Astrophysics Data System (ADS)
Kang, S.; Cockett, R.; Heagy, L. J.; Oldenburg, D.
2016-12-01
In a geophysical survey, a source injects energy into the earth and a response is measured. These physical systems are governed by partial differential equations and their numerical solutions are obtained by discretizing the earth. Geophysical simulations and inversions are tools for understanding physical responses and constructing models of the subsurface given a finite amount of data. SimPEG (http://simpeg.xyz) is our effort to synthesize geophysical forward and inverse methodologies into a consistent framework. The primary focus of our initial development has been on the electromagnetics (EM) package, with recent extensions to magnetotelluric, direct current (DC), and induced polarization. Across these methods, and applied geophysics in general, we require tools to explore and build an understanding of the physics (behaviour of fields, fluxes), and work with data to produce models through reproducible inversions. If we consider DC or EM experiments, with the aim of understanding responses from subsurface conductors, we require resources that provide multiple "entry points" into the geophysical problem. To understand the physical responses and measured data, we must simulate the physical system and visualize electric fields, currents, and charges. Performing an inversion requires that many moving pieces be brought together: simulation, physics, linear algebra, data processing, optimization, etc. Each component must be trusted, accessible to interrogation and manipulation, and readily combined in order to enable investigation into inversion methodologies. To support such research, we not only require "entry points" into the software, but also extensibility to new situations. In our development of SimPEG, we have sought to use leading practices in software development with the aim of supporting and promoting collaborations across a spectrum of geophysical research: from fundamentals to applications. Designing software to enable this spectrum puts unique constraints on both the architecture of the codebase as well as the development practices that are employed. In this presentation, we will share some lessons learned and, in particular, how our prioritization of testing, documentation, and refactoring has impacted our own research and fostered collaborations.
Learning about hydrothermal volcanic activity by modeling induced geophysical changes
NASA Astrophysics Data System (ADS)
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 state-of-the-art instruments. Devising multidisciplinary and easy-to-use computational experiments enable us to learn how the hydrothermal system responds to un unrest and which fingerprints it may leave in the geophysical signals.
NASA Astrophysics Data System (ADS)
Richter, D., Jr.; Bacon, A. R.; Brantley, S. L.; Holbrook, W. S.
2015-12-01
To understand the relationship between geophysical measurements and chemical weathering at Earth's surface, we combine comprehensive chemical and physical analyses of a 70-m granite weathering profile in the Southern Piedmont in the southeastern United States. The research site is in the uplands of the Calhoun Critical Zone Observatory and is similar to many geomorphically stable, ancient, and highly-weathered Ultisol soils of the region. Surface and downhole geophysical analyses suggest significant physical changes to depths of about 40 m, where geophysical properties are consistent with competent and unweathered granite. At this depth, surface refraction velocities increase to >4.5 km/s; variations in downhole sonic velocities decrease by more than two-fold; and deviations in the downhole caliper log sharply decrease as well. Forty meters depth is also the depth of initiation of plagioclase feldspar weathering, as inferred from bulk geochemical measurement of the full 70-m deep core. Specifically, element-depth profiles, cast as mass transfer coefficient profiles using Ti and Zr as immobile elements, document inferred loss of plagioclase in the depth interval between 15 and 40-m depth. Plagioclase feldspar is the most abundant of the highly reactive minerals in the granite. Such a wide reaction front is characteristic of weathering granites. Some loss of K is observed at these depths but most K loss, as well as Mg loss, occurs at shallower depths. Nearby geophysical profiles and 3D stress models have been interpreted as showing that seismic velocities decrease at 40 m depth due to opening of fractures as rock is exhumed toward the surface. Given our interpretations of both the geochemical and geophysical data, we infer that the onset of chemical weathering of feldspar coincides with the opening of these fractures. The data highlight the ability of geochemistry and geophysics to complement each other and enrich our understanding of Earth's Critical Zone.
Publications - GMC 213 | Alaska Division of Geological & Geophysical
') of the Shell Western E & P Inc. OCS Y-1275-1 (Popcorn #1) well Authors: Unknown Publication Date E & P Inc. OCS Y-1275-1 (Popcorn #1) well: Alaska Division of Geological & Geophysical
DOT National Transportation Integrated Search
1991-01-01
Various geophysical electrical measuring techniques, i.e., spontaneous potential (SP) terrain conductivity meter (TCM), and conventional electrical resistivity/conductivity (ER), were tested to determine their effectiveness in detecting, delineating,...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Barnhart, Kevin Scott
2013-10-01
We proposed to customize emerging in situ geophysical monitoring technology to generate time-series data during sporadic rain events in a semi-arid region. Electrodes were to be connected to wireless \
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-02
...; (2) Build the National Catalog by providing site-specific metadata for items in inventoried... geophysical data; (b) Digital infrastructure; (c) Metadata for items in data collections; and (d) Special data...
Publications - GMC 400 | Alaska Division of Geological & Geophysical
, Kashwitna Lake #1, Little Su #1, Sheep Creek #1, and Slats #1 coal-bed methane wells Authors: Posey, C.M methane wells: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center Data
Electrical Resistivity Imaging
Electrical resistivity imaging (ERI) is a geophysical method originally developed within the mining industry where it has been used for decades to explore for and characterize subsurface mineral deposits. It is one of the oldest geophysical methods with the first documented usag...
Reports of Planetary Geology and Geophysics Program, 1990
NASA Technical Reports Server (NTRS)
1991-01-01
Abstracts of reports from NASA's Planetary Geology and Geophysics Program are presented. Research is documented in summary form of the work conducted. Each report reflects significant accomplishments within the area of the author's funded grant or contract.
Innovations In Site Characterization: Geophysical Investigation at Hazardous Waste Sites
This compendium describes a number of geophysical technologies and methods that were used at 11 sites with significantly different geological settings and types of subsurface contamination, ranging from relatively homogeneous stratigraphy to the highly ...
Publications - PDF 87-2 | Alaska Division of Geological & Geophysical
content DGGS PDF 87-2 Publication Details Title: Alaska's mineral industry 1986: Executive summary Authors : Executive summary: Alaska Division of Geological & Geophysical Surveys Public Data File 87-2, 5 p. http
Publications - GMC 363 | Alaska Division of Geological & Geophysical
Division of Geological & Geophysical Surveys Comments: Excel files of grain size data and point count . http://doi.org/10.14509/20244 Publication Products Report Report Information gmc363.pdf (6.6 M) Excel
Studies in remotely sensed geophysical parameter retrieval and analysis
NASA Technical Reports Server (NTRS)
Perkey, Donald J.
1993-01-01
This report describes Universities Space Research Association (USRA) activities in support of the Geophysical Parameter Retrieval and Analysis studies. Specifically it addresses personnel assigned to the effort, travel, consultant participants, technical progress, and contract spending.
NASA Technical Reports Server (NTRS)
Cannon, W. H.; Petrachenko, W. T.; Yen, J. L.; Galt, J. A.; Waltman, W. B.; Knoweles, S. H.; Popelar, J.
1980-01-01
A pilot project to establish an operational phase stable very long baseline interferometer (VLBI) for geophysical studies is described. Methods for implementation as well as practical applications are presented.
Geophysical methods for determining the geotechnical engineering properties of earth materials.
DOT National Transportation Integrated Search
2010-03-01
Surface and borehole geophysical methods exist to measure in-situ properties and structural : characteristics of earth materials. Application of such methods has demonstrated cost savings through : reduced design uncertainty and lower investigation c...
Publications - GMC 282 | Alaska Division of Geological & Geophysical
DGGS GMC 282 Publication Details Title: Geochemical analysis of cuttings (11440'-11500') from the Exxon '-11500') from the Exxon Company U.S.A. OCS Y-0191-2 well: Alaska Division of Geological & Geophysical
Geophysical applications for arctic/subarctic transportation planning.
DOT National Transportation Integrated Search
2014-07-01
This report describes a series of geophysical surveys conducted in conjunction with : geotechnical investigations carried out by the Alaska Department of Transportation and Public : Facilities. The purpose of the study was to evaluate the value of an...
Flanigan, Vincent J.
1979-01-01
A slingram geophysical survey was made in early 1978 as part of the integrated geologlcal-geophysical study aimed at evaluating the Eleana Formation as a possible repository for nuclear waste. The slingram data were taken over an alluvial fan and pediments along the eastern flank of Syncline Ridge about 45 km north of Mercury, Nevada, on the Nevada Test Site. The data show that the more conductive argillaceous Eleana Formation varies in depth from 40 to 85 m from west to east along traverse lines. Northeast-trending linear anomalies suggest rather abrupt changes in subsurface geology that may be associated with faults and fractures. The results of the slingram survey will, when interpreted in the light of other geologic and geophysical evidence, assist in understanding the shallow parts of the geologic setting of the Eleana Formation.
Preface: Current perspectives in modelling, monitoring, and predicting geophysical fluid dynamics
NASA Astrophysics Data System (ADS)
Mancho, Ana M.; Hernández-García, Emilio; López, Cristóbal; Turiel, Antonio; Wiggins, Stephen; Pérez-Muñuzuri, Vicente
2018-02-01
The third edition of the international workshop Nonlinear Processes in Oceanic and Atmospheric Flows
was held at the Institute of Mathematical Sciences (ICMAT) in Madrid from 6 to 8 July 2016. The event gathered oceanographers, atmospheric scientists, physicists, and applied mathematicians sharing a common interest in the nonlinear dynamics of geophysical fluid flows. The philosophy of this meeting was to bring together researchers from a variety of backgrounds into an environment that favoured a vigorous discussion of concepts across different disciplines. The present Special Issue on Current perspectives in modelling, monitoring, and predicting geophysical fluid dynamics
contains selected contributions, mainly from attendants of the workshop, providing an updated perspective on modelling aspects of geophysical flows as well as issues on prediction and assimilation of observational data and novel tools for describing transport and mixing processes in these contexts. More details on these aspects are discussed in this preface.
Buesch, David C.
2014-01-01
Geologic and geophysical investigations in the vicinity of Fort Irwin National Training Center, California, have been completed in support of groundwater investigations, and are presented in eight chapters of this report. A generalized surficial geologic map along with field and borehole investigations conducted during 2010–11 provide a lithostratigraphic and structural framework for the area during the Cenozoic. Electromagnetic properties of resistivity were measured in the laboratory on hand and core samples, and compared to borehole geophysical resistivity data. These data were used in conjunction with ground-based time-domain and airborne data and interpretations to provide a framework for the shallow lithologic units and structure. Gravity and aeromagnetic maps cover areas ~4 to 5 times that of Fort Irwin. Each chapter includes hydrogeologic applications of the data or model results.
Prospect of Continuous VLBI Measurement of Earth Rotation in Monitoring Geophysical Fluids
NASA Technical Reports Server (NTRS)
Chao, Benjamin F.; Ma, Chopo; Clark, Thomas
1998-01-01
Large-scale mass transports in the geophysical fluids of the Earth system excite Earth's rotational variations in both length-of-day and polar motion. The excitation process is via the conservation of angular momentum. Therefore Earth rotation observations contain information about the integrated angular momentum (consisting of both the mass term and the motion term) of the geophysical fluids, which include atmosphere, hydrosphere, mantle, and the outer and inner cores. Such global information is often important and otherwise unattainable depending on the nature of the mass transport, its magnitude and time scale. The last few years have seen great advances in VLBI measurement of Earth rotation in precision and temporal resolution. These advances have opened new. areas in geophysical fluid studies, such as oceanic tidal angular momentum, atmospheric tides, Earth librations, and rapid atmospheric angular momentum fluctuations. Precision of 10 microseconds in UTI and 200 microarcseconds in polar motion can now be achieved on hourly basis. Building upon this heritage, the multi-network geodetic VLBI project, Continuous Observation of the Rotation of the Earth (CORE), promises to further these studies and to make possible studies on elusive but tell-tale geophysical processes such as oscillatory modes in the core and in the atmosphere. Currently the early phase of CORE is underway. Within a few years into the new mellinnium, the upcoming space gravity missions (such as GRACE) will measure the temporal variations in Earth's gravitational field, thus providing complementary information to that from Earth rotation study for a better understanding of global geophysical fluid processes.
Geophysical monitoring of a field-scale biostimulation pilot project
Lane, J.W.; Day-Lewis, F. D.; Casey, C.C.
2006-01-01
The USGS conducted a geophysical investigation in support of a U.S. Naval Facilities Engineering Command, Southern Division field-scale biostimulation pilot project at Anoka County Riverfront Park (ACP), downgradient of the Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota. The goal of the pilot project is to evaluate subsurface injection of vegetable oil emulsion (VOE) to stimulate microbial degradation of chlorinated hydrocarbons. To monitor the emplacement and movement of the VOE and changes in water chemistry resulting from VOE dissolution and/or enhanced biological activity, the USGS acquired cross-hole radar zero-offset profiles, traveltime tomograms, and borehole geophysical logs during five site visits over 1.5 years. Analysis of pre- and postinjection data sets using petrophysical models developed to estimate VOE saturation and changes in total dissolved solids provides insights into the spatial and temporal distribution of VOE and ground water with altered chemistry. Radar slowness-difference tomograms and zero-offset slowness profiles indicate that the VOE remained close to the injection wells, whereas radar attenuation profiles and electromagnetic induction logs indicate that bulk electrical conductivity increased downgradient of the injection zone, diagnostic of changing water chemistry. Geophysical logs indicate that some screened intervals were located above or below zones of elevated dissolved solids; hence, the geophysical data provide a broader context for interpretation of water samples and evaluation of the biostimulation effort. Our results include (1) demonstration of field and data analysis methods for geophysical monitoring of VOE biostimulation and (2) site-specific insights into the spatial and temporal distributions of VOE at the ACP. ?? 2006 National Ground Water Association.
NASA Astrophysics Data System (ADS)
Sobissevitch, Leonid E.; Sobissevitch, Alex L.; Kanonidi, Konstantin Kh.; Filippov, Ivan N.
2010-05-01
The new geophysical observatory for fundamental scientific studies of geophysical processes in the Elbrus volcanic area (Northern Caucasus) has been organized recently as a result of merging of five geophysical laboratories positioned round the Elbrus volcano and equipped with modern geophysical instruments including broadband tri-axial seismometers, quartz tilt-meters, magnetic variometers, geo-acoustic sensors, hi-precision distributed thermal sensors, gravimeters, and network-enabled data acquisition systems with precise GPS-timing and integrated monitoring of auxiliary parameters (variations on ambient humidity, atmospheric pressure etc). Two laboratories are located in the horizontal 4.3 km deep tunnel drilled under the mount Andyrchi, about 20 km from the Elbrus volcano. Analysis of multi-parameter streams of experimental data allows one to study the structure of geophysical wave fields induced by earthquakes and regional catastrophic events (including snow avalanches). On the basis of continuous observations carried out since 2007 there have been determined anomalous wave forms in ULF geomagnetic variations preceding strong seismic events with magnitude 7 or more. Mentioned wave forms may be natively related to processes of evolution of dilatational structures in a domain of forthcoming seismic event. Specific patterns in anomalous ULF wave forms are distinguished for undersea earthquakes and for earthquakes responsible for triggering tsunami events. Thus, it is possible to consider development of a future technology to suggest the possible area and the time frame of such class of catastrophic events with additional reference to forecast information (including acoustic, hydro-acoustic and geo-acoustic) being concurrently analyzed.
Geophysical monitoring of a field-scale biostimulation pilot project.
Lane, John W; Day-Lewis, Frederick D; Casey, Clifton C
2006-01-01
The USGS conducted a geophysical investigation in support of a U.S. Naval Facilities Engineering Command, Southern Division field-scale biostimulation pilot project at Anoka County Riverfront Park (ACP), down-gradient of the Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota. The goal of the pilot project is to evaluate subsurface injection of vegetable oil emulsion (VOE) to stimulate microbial degradation of chlorinated hydrocarbons. To monitor the emplacement and movement of the VOE and changes in water chemistry resulting from VOE dissolution and/or enhanced biological activity, the USGS acquired cross-hole radar zero-offset profiles, travel-time tomograms, and borehole geophysical logs during five site visits over 1.5 years. Analysis of pre- and postinjection data sets using petrophysical models developed to estimate VOE saturation and changes in total dissolved solids provides insights into the spatial and temporal distribution of VOE and ground water with altered chemistry. Radar slowness-difference tomograms and zero-offset slowness profiles indicate that the VOE remained close to the injection wells, whereas radar attenuation profiles and electromagnetic induction logs indicate that bulk electrical conductivity increased down-gradient of the injection zone, diagnostic of changing water chemistry. Geophysical logs indicate that some screened intervals were located above or below zones of elevated dissolved solids; hence, the geophysical data provide a broader context for interpretation of water samples and evaluation of the biostimulation effort. Our results include (1) demonstration of field and data analysis methods for geophysical monitoring of VOE biostimulation and (2) site-specific insights into the spatial and temporal distributions of VOE at the ACP.
Automatic mapping of the base of aquifer — A case study from Morrill, Nebraska
Gulbrandsen, Mats Lundh; Ball, Lyndsay B.; Minsley, Burke J.; Hansen, Thomas Mejer
2017-01-01
When a geologist sets up a geologic model, various types of disparate information may be available, such as exposures, boreholes, and (or) geophysical data. In recent years, the amount of geophysical data available has been increasing, a trend that is only expected to continue. It is nontrivial (and often, in practice, impossible) for the geologist to take all the details of the geophysical data into account when setting up a geologic model. We have developed an approach that allows for the objective quantification of information from geophysical data and borehole observations in a way that is easy to integrate in the geologic modeling process. This will allow the geologist to make a geologic interpretation that is consistent with the geophysical information at hand. We have determined that automated interpretation of geologic layer boundaries using information from boreholes and geophysical data alone can provide a good geologic layer model, even before manual interpretation has begun. The workflow is implemented on a set of boreholes and airborne electromagnetic (AEM) data from Morrill, Nebraska. From the borehole logs, information about the depth to the base of aquifer (BOA) is extracted and used together with the AEM data to map a surface that represents this geologic contact. Finally, a comparison between our automated approach and a previous manual mapping of the BOA in the region validates the quality of the proposed method and suggests that this workflow will allow a much faster and objective geologic modeling process that is consistent with the available data.
Impact of geophysical model error for recovering temporal gravity field model
NASA Astrophysics Data System (ADS)
Zhou, Hao; Luo, Zhicai; Wu, Yihao; Li, Qiong; Xu, Chuang
2016-07-01
The impact of geophysical model error on recovered temporal gravity field models with both real and simulated GRACE observations is assessed in this paper. With real GRACE observations, we build four temporal gravity field models, i.e., HUST08a, HUST11a, HUST04 and HUST05. HUST08a and HUST11a are derived from different ocean tide models (EOT08a and EOT11a), while HUST04 and HUST05 are derived from different non-tidal models (AOD RL04 and AOD RL05). The statistical result shows that the discrepancies of the annual mass variability amplitudes in six river basins between HUST08a and HUST11a models, HUST04 and HUST05 models are all smaller than 1 cm, which demonstrates that geophysical model error slightly affects the current GRACE solutions. The impact of geophysical model error for future missions with more accurate satellite ranging is also assessed by simulation. The simulation results indicate that for current mission with range rate accuracy of 2.5 × 10- 7 m/s, observation error is the main reason for stripe error. However, when the range rate accuracy improves to 5.0 × 10- 8 m/s in the future mission, geophysical model error will be the main source for stripe error, which will limit the accuracy and spatial resolution of temporal gravity model. Therefore, observation error should be the primary error source taken into account at current range rate accuracy level, while more attention should be paid to improving the accuracy of background geophysical models for the future mission.
Publications - GMC 75 | Alaska Division of Geological & Geophysical Surveys
DGGS GMC 75 Publication Details Title: Vitrinite reflectance data for the Chevron U.S.A. Inc. Eagle Chevron U.S.A. Inc. Eagle Creek #1 well: Alaska Division of Geological & Geophysical Surveys Geologic
Code of Federal Regulations, 2014 CFR
2014-07-01
... include, but is not limited to, identification of lithologic and fossil content, core analyses, laboratory... geophysical information. Interpreted geological information means knowledge, often in the form of schematic... geological information. Interpreted geophysical information means knowledge, often in the form of schematic...
Code of Federal Regulations, 2012 CFR
2012-07-01
... include, but is not limited to, identification of lithologic and fossil content, core analysis, laboratory... means geological knowledge, often in the form of schematic cross sections, 3-dimensional representations... information. Interpreted geophysical information means geophysical knowledge, often in the form of schematic...
Code of Federal Regulations, 2013 CFR
2013-07-01
... include, but is not limited to, identification of lithologic and fossil content, core analyses, laboratory... geophysical information. Interpreted geological information means knowledge, often in the form of schematic... geological information. Interpreted geophysical information means knowledge, often in the form of schematic...
Code of Federal Regulations, 2012 CFR
2012-07-01
... include, but is not limited to, identification of lithologic and fossil content, core analyses, laboratory... geophysical information. Interpreted geological information means knowledge, often in the form of schematic... geological information. Interpreted geophysical information means knowledge, often in the form of schematic...
Code of Federal Regulations, 2014 CFR
2014-07-01
... include, but is not limited to, identification of lithologic and fossil content, core analyses, laboratory... geophysical information. Interpreted geological information means knowledge, often in the form of schematic... geological information. Interpreted geophysical information means knowledge, often in the form of schematic...
Code of Federal Regulations, 2013 CFR
2013-07-01
... include, but is not limited to, identification of lithologic and fossil content, core analyses, laboratory... geophysical information. Interpreted geological information means knowledge, often in the form of schematic... geological information. Interpreted geophysical information means knowledge, often in the form of schematic...
Code of Federal Regulations, 2012 CFR
2012-07-01
... include, but is not limited to, identification of lithologic and fossil content, core analyses, laboratory... geophysical information. Interpreted geological information means knowledge, often in the form of schematic... geological information. Interpreted geophysical information means knowledge, often in the form of schematic...
Application of innovative nondestructive methods to geotechnical and environmental investigations
DOT National Transportation Integrated Search
2003-04-01
Geophysical surveys were conducted for the Missouri Department of Transportation (MoDOT) by the Department of Geology and Geophysics at the University of Missouri-Rolla. This report contains the results of several projects that utilized nondestructiv...
Publications - GMC 359 | Alaska Division of Geological & Geophysical
of Geological & Geophysical Surveys Comments: Raw data provided in excel table. Chromatograms gmc359.pdf (294.0 K) Excel Data Table(s) gmc359.xls (332.0 K) Keywords Geochemical Data Top of Page
Publications - GMC 191 | Alaska Division of Geological & Geophysical
(3,489'-3,511') from the Union Oil Co. of California Ruby State #1 well Authors: Unknown Publication Date the Union Oil Co. of California Ruby State #1 well: Alaska Division of Geological & Geophysical
Publications - GMC 218 | Alaska Division of Geological & Geophysical
') of the Shell Western E & P Inc. OCS Y-1482-1 (Klondike #1) well Authors: Unknown Publication Date Western E & P Inc. OCS Y-1482-1 (Klondike #1) well: Alaska Division of Geological & Geophysical
NASA Astrophysics Data System (ADS)
Eppelbaum, L. V.; Masini, N.; Soldovieri, F.
2010-06-01
This special issue of the Journal of Geophysics and Engineering hosts a selection of the papers that were presented at the session entitled `Near surface geophysics for the study and the management of historical resources: past, present and future', organized within the framework of the General Assembly of the European Geosciences Union (Vienna, Austria, 19-24 April 2009). As the conveners, we invited the active participants of this session to prepare papers reflecting their presentations and submit them for publication in the Journal of Geophysics and Engineering. This special issue presents the papers which have passed through the prolonged and stringent reviewing process. The papers presented in this issue illustrate the application of novel instrumentation, surface and airborne remote sensing techniques, as well as data processing oriented both to new archaeological targets characterization and cultural heritage conservation. In this field, increasing interest has been observed in recent years in non-destructive and non-invasive geophysical test methods. They allow one to overcome the subjectivity and ambiguity arising from the number and locations of the sites chosen to perform the destructive examination. In addition, very recently, much attention has been given to the integration of the classical geophysical techniques (GPR, magnetic, ERT, IP) with new emerging surface and subsurface sensing techniques (optical sensors, lidar, microwave tomography, MASW) for a combined monitoring of archaeological constructions and artefacts. We hope that the presented research papers will be interesting for readers in the different branches of environmental and cultural heritage sciences and will attract new potential contributors to the important topics of archaeological targets recognition, cultural heritage monitoring and diagnostics. Statistically, every day several tens of significant archaeological objects are destroyed and damaged throughout the Earth, and we hope that our investigation will help to decrease these losses. We wish to thank all the authors for their presentations and fruitful discussions at the session and for preparing these articles. We are grateful to all the reviewers whose accurate and hard work has made the successful publication of this special issue possible. We also thank the editors and managers of the Journal of Geophysics and Engineering (particularly Sarah Quin) for their skilled and pleasant collaboration.
NASA Astrophysics Data System (ADS)
Karabulut, Savas; Baris Aygordu, Ozan; Benli, Aral
2015-04-01
This survey was conducted in order to make the students who are having geophysical engineering education in Turkey evaluate their departments from their own perspectives.By doing this we aimed to make a contribution to the geophysical engineering education and we tried to find out if there were any deficiencies in that matter and also the possible solutions.In this respect aproximately 500 undergraduates from 11 different state universities were asked 25 questions regarding both their socio-economic status and their ideas on their future professions.In the survey the students were asked to state their high-school graduation;whether it is an Anatolian High-school,Vocational high-school or college and if geophysical engineering education was their first choice at the university entrance exams.The students' foreign language status-if there were any- except their mother tongue were asked and also their opinions on geophysical education at their universities.Besides these the students were asked in which fields they study in their department; Seismology, Geophysics or Applied Geophysics and if they found the geophysical equipments adequate in their departments and also the programming languages-like data processing laboratories.In the survey we tried to find out if the students were encouraged to participate in the meetings and congresses in their field by their instructers and if they found the theoretical training adequate besides the practical one.Above all the students answered questions if they had any worries about future job opportunities ; what their goals were after they graduate and if they could easily get access to any kind of Turkish sources in their field and if they were reluctant to work at any jobs part-time or full-time during university.The results of the survey were presented to the Union of Turkish Engineers and Architects and also to the related heads of departments.The most striking parts of this survey were that the students were not edequate enough to interpret and analyse the foreign articles and journeys because of their poor foreign language levels and % 80,5 were very anxious to get a proper job in the future and %78,6 did not find the sources edequate in Turkish and %91,8 of these students thought that theoratical training was not enough besides practical one.
Reports of planetary geology and geophysics program, 1989
NASA Technical Reports Server (NTRS)
Holt, Henry (Editor)
1990-01-01
Abstracts of reports from Principal Investigators of NASA's Planetary Geology and Geophysics Program are compiled. The research conducted under this program during 1989 is summarized. Each report includes significant accomplishments in the area of the author's funded grant or contract.
Seismic Waveform Analysis of Underground Nuclear Explosions
1979-11-15
parameters to be discussed here are Bouguer gravity (Figure 18), and station elevation (Figure 19). Tn this simple comparison of various geophysical...noted the frequent strong correlation between Bouguer gravity and elevation. Indeed, many of the geophysical parameters discussed above are interrelated
Student Enrollment in Geoscience Departments. 1982-1983.
ERIC Educational Resources Information Center
American Geological Inst., Washington, DC.
Presented in table format are student enrollment data for geoscience disciplines at colleges and universities in the United States and Canada. Subfields for both countries include: geology; geophysics; oceanography; marine science; geological engineering; geophysical engineering; geochemistry; hydrology; mineralogy; paleontology; soil science;…
Publications - DDS 12 | Alaska Division of Geological & Geophysical Surveys
; Geophysical Surveys Digital Data Series 12, 1 DVD. http://doi.org/10.14509/29555 Publication Products Disc DVD catalog (34.0 M) Digital Geospatial Data Digital Geospatial Data Black Mtn., Liscum, Goodpaster, Salch R
Induced polarization research at Kennecott, 1965-1977
Nelson, Philip H.
1997-01-01
Geophysics research and development (R&D) was a small research group at Kennecott Inc. (KEI), a subsidiary of Kennecott Copper Corporation. The research group served Geophysics-Operations, which in turn worked for another subsidiary, Bear Creek Mining Company (BCMC). BCMC did Kennecott's exploration work such as reconnaissance mapping, staking and proving up claims, and assessment drilling. The working environment at Geophysics R&D included emphasis on instrument development and being strongly field oriented; having entrepreneurial leaders engaged in technical work; interaction between R&D and its `customer', the Operations group and; emphasis on lowering costs and increasing production.
Selected Papers on Noctilucent Clouds
NASA Technical Reports Server (NTRS)
1963-01-01
The papers presented herein were taken from two Russian publications on the International Geophysical Year. The first four articles (footnoted Certain Articles Regarding Meteorology") are from Nekotoryye Problemy Meteorologii; Sbornik Statey, II Razdel Programmy MGG (Meteorologiya), No. 1, Izdat. Akademii Nauk SSSR (Certain Problems Regarding Meteorology; Collection of Articles, Second Section of the IGY Program (Meteorology), No. 1. Published by the Academy of Sciences Press) Moscow, 1960. The last two articles (footnoted "International Geophysical Year") are from Mezhdunarodnoy Geofizicheskiy God; Sbornik Statey i Materialov, Izdat. Leningradskogo Universiteta (International Geophysical Year; Collection of Articles and Materials. Published by the Leningrad University Press) 1960.
20th National Solar Physics Meeting
NASA Astrophysics Data System (ADS)
Dorotovic, Ivan
2010-12-01
These proceedings (ISBN: 978-80-85221-68-8) provide an overview of current research on solar physics, geophysics and space weather in the astronomical, geophysical and space physics institutions in the Slovak Republic and the Czech Republic. Several researchers from other countries participated in the meeting as well. The different parts address: solar interior, solar photosphere, chromosphere, corona, total solar eclipses, space weather, instrumentation. Most of the papers are published in Slovak and Czech, respectively. The proceedings are intended for researchers, graduate and PhD. students, workers of astronomical observatories interested in solar physics, geophysics and space weather.
Publications of the Volcano Hazards Program 2011
Nathenson, Manuel
2013-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity, as funded by Congressional appropriation. Investigations are carried out by the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Manoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. Only published papers and maps are included here; abstracts presented at scientific meetings are omitted. Publication dates are based on year of issue, with no attempt to assign them to fiscal year.
Solar wind monitor—a school geophysics project
NASA Astrophysics Data System (ADS)
Robinson, Ian
2018-05-01
Described is an established geophysics project to construct a solar wind monitor based on a nT resolution fluxgate magnetometer. Low-cost and appropriate from school to university level it incorporates elements of astrophysics, geophysics, electronics, programming, computer networking and signal processing. The system monitors the earth’s field in real-time uploading data and graphs to a website every few minutes. Modular design encourages construction and testing by teams of students as well as expansion and refinement. The system has been tested running unattended for months at a time. Both the hardware design and software is published as open-source [1, 10].
DOE R&D Accomplishments Database
Teller, E.; Leith, C.; Canavan, G.; Marion, J.; Wood, L.
2001-11-13
A gap-free, world-wide, ocean-, atmosphere-, and land surface-spanning geophysical data-set of three decades time-duration containing the full set of geophysical parameters characterizing global weather is the scientific perquisite for defining the climate; the generally-accepted definition in the meteorological community is that climate is the 30-year running-average of weather. Until such a tridecadal climate baseline exists, climate change discussions inevitably will have a semi-speculative, vs. a purely scientific, character, as the baseline against which changes are referenced will at least somewhat uncertain.
Geophysical characteristics and crustal structure of greenstone terranes: Canadian Shield
NASA Technical Reports Server (NTRS)
Thomas, M. D.; Losier, L.; Thurston, P. C.; Gupta, V. K.; Gibb, R. A.; Grieve, R. A. F.
1986-01-01
Geophysical studies in the Canadian Shield have provided some insights into the tectonic setting of greenstone belts. Greenstone belts are not rooted in deep crustal structures. Geophysical techniques consistently indicate that greenstones are restricted to the uppermost 10 km or so of crust and are underlain by geophysically normal crust. Gravity models suggest that granitic elements are similarly restricted, although magnetic modelling suggests possible downward extension to the intermediate discontinuity around approx. 18 km. Seismic evidence demonstrates that steeply-dipping structure, which can be associated with the belts in the upper crust, is not present in the lower crust. Horizontal intermediate discontinuities mapped under adjacent greenstone and granitic components are not noticeably disrupted in the boundary zone. Geophysical evidence points to the presence of discontinuities between greenhouse-granite and adjacent metasedimentary erranes. Measured stratigraphic thicknesses of greenstone belts are often twice or more the vertical thicknesses determined from gravity modelling. Explantations advanced for the discrepancy include stratigraphy repeated by thrust faulting and/or listric normal faulting, mechanisms which are consistent with certain aspects of conceptual models of greenstone development. Where repetition is not a factor the gravity evidence points to removal of the root zones of greenstone belts. For one region, this has been attributed to magmatic stopping during resurgent caldera activity.
NASA Astrophysics Data System (ADS)
Pueyo-Anchuela, Ó.; Casas-Sainz, A. M.; Soriano, M. A.; Pocoví-Juan, A.
Complex geological shallow subsurface environments represent an important handicap in urban and building projects. The geological features of the Central Ebro Basin, with sharp lateral changes in Quaternary deposits, alluvial karst phenomena and anthropic activity can preclude the characterization of future urban areas only from isolated geomechanical tests or from non-correctly dimensioned geophysical techniques. This complexity is here analyzed in two different test fields, (i) one of them linked to flat-bottomed valleys with irregular distribution of Quaternary deposits related to sharp lateral facies changes and irregular preconsolidated substratum position and (ii) a second one with similar complexities in the alluvial deposits and karst activity linked to solution of the underlying evaporite substratum. The results show that different geophysical techniques allow for similar geological models to be obtained in the first case (flat-bottomed valleys), whereas only the application of several geophysical techniques can permit to correctly evaluate the geological model complexities in the second case (alluvial karst). In this second case, the geological and superficial information permit to refine the sensitivity of the applied geophysical techniques to different indicators of karst activity. In both cases 3D models are needed to correctly distinguish alluvial lateral sedimentary changes from superimposed karstic activity.
Conger, Randall W.
2000-01-01
Between November 1998 and May 1999, geophysical logging was conducted in 29 boreholes at the Crossley Farms Superfund Site, Hereford Township, Berks County, Pa., to determine the fluidproducing zones, fluid-receiving zones, zones of vertical borehole flow, and casing depth. The wells range in depth from 96 to 500 feet below land surface. Gamma logs only were collected in three bedrock wells. The geophysical logging determined the placement of well screens and packers, which allow monitoring and sampling of water-bearing zones in the fractured bedrock so that the horizontal and vertical distribution of contaminated ground water migrating from known sources could be determined. Geophysical logging included collection of caliper, video, fluid-temperature, fluid-resistivity, single-point-resistance, natural-gamma, fluid-flow, and acoustic-televiewer logs. Caliper and video logs were used to locate fractures, joints, and weathered zones. Inflections on fluidtemperature and fluid-resistivity logs indicated possible water-bearing fractures, and flowmeter measurements verified these locations. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical, video logs, and drillers notes, 24 of the wells were reconstructed such that water levels can be monitored and water samples collected from discrete water-bearing fractures in each well.
Ninety Years of International Cooperation in Geophysics
NASA Astrophysics Data System (ADS)
Ismail-Zadeh, A.; Beer, T.
2009-05-01
Because applicable physical, chemical, and mathematical studies of the Earth system must be both interdisciplinary and international, the International Union of Geodesy and Geophysics (IUGG) was formed in 1919 as an non-governmental, non-profit organization dedicated to advancing, promoting, and communicating knowledge of the Earth system, its space environment, and the dynamical processes causing change. The Union brings together eight International Associations that address different disciplines of Earth sciences. Through these Associations, IUGG promotes and enables studies in the geosciences by providing a framework for collaborative research and information exchange, by organizing international scientific assemblies worldwide, and via research publications. Resolutions passed by assemblies of IUGG and its International Associations set geophysical standards and promote issues of science policy on which national members agree. IUGG has initiated and/or vigorously supported collaborative international efforts that have led to highly productive worldwide interdisciplinary research programs, such as the International Geophysical Year and subsequent International Years (IPY, IYPE, eGY, and IHY), International Lithosphere Programme, World Climate Research Programme, Geosphere-Biosphere Programme, and Integrated Research on Risk Disaster. IUGG is inherently involved in the projects and programs related to climate change, global warming, and related environmental impacts. One major contribution has been the creation, through the International Council for Science (ICSU), of the World Data Centers and the Federation of Astronomical and Geophysical Data Analysis Services. These are being transformed to the ICSU World Data System, from which the data gathered during the major programs and data products will be available to researchers everywhere. IUGG cooperates with UNESCO, WMO, and some other U.N. and non-governmental organizations in the study of natural catastrophes, climate dynamics, and in geodetic, hydrological, meteorological, oceanographic, seismological, and volcanological research. IUGG also places particular emphasis on the scientific problems of economically less-developed countries by sponsoring activities relevant to their scientific needs (e.g. Geosciences in Africa, Water Resources, Health and Well-Being etc.) The American Geophysical Union was established as the U.S. National Committee for IUGG in 1919 and today has become a distinguished union of individual geoscientists around the world. Several regional geoscience societies also evolved during the last several decades, most prominent being the European Geosciences Union and the Asia Oceania Geosciences Society. These, and some other national and regional geophysical societies, together with IUGG play a strong part in the international cooperation and promotion of geophysical sciences. At the same time the "geosciences" space is getting crowded, and there is a lot of overlap. International linkages between IUGG, AGU, EGU and other geophysical societies as well as their linkage with International Scientific Unions, that comprise the GeoUnions, are going to become more and more important. Working together is going to be more fruitful than territorial disputes. But what mechanisms can be used to encourage relationships between the international, national and regional geophysical and geoscientific bodies? We will discuss some possibilities on how to come together, to develop and to implement joint programs, research meeting, open forums, and policy statements.
NASA Technical Reports Server (NTRS)
1989-01-01
A compilation is presented of selected bibliographic data relating to recent publications submitted by principal investigators and their associates, supported through NASA's Office of Space Science and Applications, Solar System Exploration Division, Planetary Geology and Geophysics Program
Temporal Geophysical Signatures Due to Contaminant Mass Remediation
Geophysical surveys acquired over a ten year period are used to document changes in bulk electrical conductivity associated with the attenuation of hydrocarbon contaminants at the former fire training facility (FT-02) Wurtsmith Air Force base (WAFB), Oscoda, MI, USA. Initial inv...
Geophysical methods are used increasingly for characterization and monitoring at remediation sites in fractured-rock aquifers. The complex heterogeneity of fractured rock poses enormous challenges to groundwater remediation professionals, and new methods are needed to cost-effect...
COUPLED GEOPHYSICAL-HYDROLOGICAL MODELING OF A CONTROLLED NAPL SPILL
Past studies have shown reasonable sensitivity of geophysical data for detecting or monitoring the movement of non-aqueous phase liquids (NAPLs) in the subsurface. However, heterogeneity in subsurface properties and in NAPL distribution commonly results in non-unique data
...
Temporal GPR Imaging of an Ethanol Release Within a Laboratory-Scaled Sand Tank
Within the last decade efforts in geophysical detection and monitoring of fossil fuel releases into the subsurface have shown increasing success, including the ability to geophysically detect and delineate enhanced and natural biodegradation and remediation activities. The subst...
Interest focuses on exploratory areas
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stremel, K.
1984-10-01
Speculative geophysical programs are underway in sparsely drilled areas throughout the southern Rocky Mountain region. Responding to significant operator interest generated by new production in Nevada, a few contractors are designing programs to establish optimum recording parameters. Geophysical exploration activities in Colorado and Utah are discussed.
DOT National Transportation Integrated Search
2003-03-01
Geophysical surveys were conducted for the Missouri Department of Transportation (MoDOT) by the Department of Geology and Geophysics at the University of Missouri-Rolla. This report contains the results of several projects that utilized nondestructiv...
A Geophysical Atlas for Interpretation of Satellite-derived Data
NASA Technical Reports Server (NTRS)
Lowman, P. D., Jr. (Editor); Frey, H. V. (Editor); Davis, W. M.; Greenberg, A. P.; Hutchinson, M. K.; Langel, R. A.; Lowrey, B. E.; Marsh, J. G.; Mead, G. D.; Okeefe, J. A.
1979-01-01
A compilation of maps of global geophysical and geological data plotted on a common scale and projection is presented. The maps include satellite gravity, magnetic, seismic, volcanic, tectonic activity, and mantle velocity anomaly data. The Bibliographic references for all maps are included.
US National Report to International Union of Geodesy and Geophysics 1987-1990
DOE Office of Scientific and Technical Information (OSTI.GOV)
USAF, Geophysics Laboratory, Hanscom AFB, MA
1991-01-01
An authoritative record of contributions of geophysical research in the U.S. during 1987-1990 is reported. Major areas of research include atmospheric sciences, geodesy, hydrology, planetology, geomagnetism, paleomagnetism, volcanology, geochemistry, petrology, oceanography, seismology, tectonophysics, and solar-planetary relations.
Geophysical Technologies to Image Old Mine Works
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kanaan Hanna; Jim Pfeiffer
2007-01-15
ZapataEngineering, Blackhawk Division performed geophysical void detection demonstrations for the US Department of Labor Mine Safety and Health Administration (MSHA). The objective was to advance current state-of-practices of geophysical technologies for detecting underground mine voids. The presence of old mine works above, adjacent, or below an active mine presents major health and safety hazards to miners who have inadvertently cut into locations with such features. In addition, the presence of abandoned mines or voids beneath roadways and highway structures may greatly impact the performance of the transportation infrastructure in terms of cost and public safety. Roads constructed over abandoned minesmore » are subject to potential differential settlement, subsidence, sinkholes, and/or catastrophic collapse. Thus, there is a need to utilize geophysical imaging technologies to accurately locate old mine works. Several surface and borehole geophysical imaging methods and mapping techniques were employed at a known abandoned coal mine in eastern Illinois to investigate which method best map the location and extent of old works. These methods included: 1) high-resolution seismic (HRS) using compressional P-wave (HRPW) and S-wave (HRSW) reflection collected with 3-D techniques; 2) crosshole seismic tomography (XHT); 3) guided waves; 4) reverse vertical seismic profiling (RVSP); and 5) borehole sonar mapping. In addition, several exploration borings were drilled to confirm the presence of the imaged mine voids. The results indicated that the RVSP is the most viable method to accurately detect the subsurface voids with horizontal accuracy of two to five feet. This method was then applied at several other locations in Colorado with various topographic, geologic, and cultural settings for the same purpose. This paper presents the significant results obtained from the geophysical investigations in Illinois.« less
NASA Astrophysics Data System (ADS)
Casas, Albert; Cosentino, Pietro L.; Fiandaca, Gianluca; Himi, Mahjoub; Macias, Josep M.; Martorana, Raffaele; Muñoz, Andreu; Rivero, Lluís; Sala, Roger; Teixell, Imma
2018-04-01
An integrated geophysical survey has been conducted at the Tarragona's Cathedral (Catalonia, NE Spain) with the aim to confirm the potential occurrence of archaeological remains of the Roman Temple dedicated to the Emperor Augustus. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most renowned temples of Spain (twelfth century) evolving from Romanesque to Gothic styles. A geophysical project including electrical resistivity tomography (ERT) and ground probing radar (GPR) was planned over 1 year considering the administrative and logistic difficulties of such a project inside a cathedral of religious veneration. Finally, both ERT and GPR have been conducted during a week of intensive overnight surveys that provided detailed information on subsurface existing structures. The ERT method has been applied using different techniques and arrays, ranging from standard Wenner-Schlumberger 2D sections to full 3D electrical imaging with the advanced Maximum Yield Grid array. Electrical resistivity data were recorded extensively, making available many thousands of apparent resistivity data to obtain a complete 3D image after a full inversion. In conclusion, some significant buried structures have been revealed providing conclusive information for archaeologists. GPR results provided additional information about shallowest structures. The geophysical results were clear enough to persuade religious authorities and archaeologists to conduct selected excavations in the most promising areas that confirmed the interpretation of geophysical data. In conclusion, the significant buried structures revealed by geophysical methods under the cathedral were confirmed by archaeological digging as the basement of the impressive Roman Temple that headed the Provincial Forum of Tarraco, seat of the Concilium of Hispania Citerior Province.
Saltus, R.W.; Day, W.C.
2006-01-01
The Yukon-Tanana Upland is a complex composite assemblage of variably metamorphosed crystalline rocks with strong North American affinities. At the broadest scale, the Upland has a relatively neutral magnetic character. More detailed examination, however, reveals a fundamental northeast-southwest-trending magnetic gradient, representing a 20-nT step (as measured at a flight height of 300 m) with higher values to the northwest, that extends from the Denali fault to the Tintina fault and bisects the Upland. This newly recognized geophysical gradient is parallel to, but about 100 km east of, the Shaw Creek fault. The Shaw Creek fault is mapped as a major left-lateral, strike-slip fault, but does not coincide with a geophysical boundary. A gravity gradient coincides loosely with the southwestern half of the magnetic gradient. This gravity gradient is the eastern boundary of a 30-mGal residual gravity high that occupies much of the western and central portions of the Big Delta quadrangle. The adjacent lower gravity values to the east correlate, at least in part, with mapped post-metamorphic granitic rocks. Ground-based gravity and physical property measurements were made in the southeastern- most section of the Big Delta quadrangle in 2004 to investigate these geophysical features. Preliminary geophysical models suggest that the magnetic boundary is deeper and more fundamental than the gravity boundary. The two geophysical boundaries coincide in and around the Tibbs Creek region, an area of interest to mineral exploration. A newly mapped tectonic zone (the Black Mountain tectonic zone of O'Neill and others, 2005) correlates with the coincident geophysical boundaries.
Geophysical analysis for the Ada Tepe region (Bulgaria) - case study
NASA Astrophysics Data System (ADS)
Trifonova, Petya; Metodiev, Metodi; Solakov, Dimcho; Simeonova, Stela; Vatseva, Rumiana
2013-04-01
According to the current archeological investigations Ada Tepe is the oldest gold mine in Europe with Late Bronze and Early Iron age. It is a typical low-sulfidation epithermal gold deposit and is hosted in Maastrichtian-Paleocene sedimentary rocks above a detachment fault contact with underlying Paleozoic metamorphic rocks. Ada Tepe (25o.39'E; 41o.25'N) is located in the Eastern Rhodope unit. The region is highly segmented despite the low altitude (470-750 m) due to widespread volcanic and sediment rocks susceptible to torrential erosion during the cold season. Besides the thorough geological exploration focused on identifying cost-effective stocks of mineral resources, a detailed geophysical analysis concernig diferent stages of the gold extraction project was accomplished. We present the main results from the geophysical investigation aimed to clarify the complex seismotectonic setting of the Ada Tepe site region. The overall study methodology consists of collecting, reviewing and estimating geophysical and seismological information to constrain the model used for seismic hazard assessment of the area. Geophysical information used in the present work consists of gravity, geomagnetic and seismological data. Interpretation of gravity data is applied to outline the axes of steep gravity transitions marked as potential axes of faults, flexures and other structures of dislocation. Direct inverse techniques are also utilized to estimate the form and depth of anomalous sources. For the purposes of seismological investigation of the Ada Tepe site region an earthquake catalogue is compiled for the time period 510BC - 2011AD. Statistical parameters of seismicity - annual seismic rate parameter, ?, and the b-value of the Gutenberg-Richter exponential relation for Ada Tepe site region, are estimated. All geophysical datasets and derived results are integrated using GIS techniques ensuring interoperability of data when combining, processing and visualizing obtained information from different sources.
NASA Astrophysics Data System (ADS)
Panisova, Jaroslava; Murín, Igor; Pašteka, Roman; Haličková, Jana; Brunčák, Peter; Pohánka, Vladimír; Papčo, Juraj; Milo, Peter
2016-04-01
Recording of the historic edifice using the state-of-the-art geodetic and geophysical techniques brings easier visualisation in form of a three-dimensional (3D) model, thus allowing better understanding of its historical construction by the public and non-experts. We have applied this approach at the Church of St. George, one of the most significant religious buildings in south-western Slovakia, which dominates a silhouette of the town Svätý Jur. The geodetic survey allowed to record the actual state of the church. The church exterior was surveyed using a total station. Due to the intricate shape of the interior components of the church, it was decided to use a terrestrial laser scanner to generate the point cloud data, which were processed into floor plan, elevations, sectional 2D drawings and 3D model. The geophysical survey was carried out in the interior of the church in order to identify potential subsurface anthropogenic structures. Microgravity and ground penetrating radar (GPR) methods were selected as the most effective geophysical tools for such task. In microgravity data processing we focused on the calculation and removal of the gravitational effects of the building masses. The main negative gravity anomalies of interest in the nave, which also have been confirmed by GPR measurements, are interpreted as medieval crypts. Another very important outcome of the geophysical survey is the discovery of the west wall foundations of the oldest Romanesque construction. From each geophysical data acquired we derived 3D polygonal models, which are compared to achieve more realistic picture of the subsurface structures. Verification of these structures by means of archaeological excavation has not been carried out yet.
Geophysical anatomy of counter-slope scarps in sedimentary flysch rocks (Outer Western Carpathians)
NASA Astrophysics Data System (ADS)
Tábořík, P.; Lenart, J.; Blecha, V.; Vilhelm, J.; Turský, O.
2017-01-01
A multidisciplinary geophysical survey, consisting of electrical resistivity tomography (ERT), ground penetrating radar (GPR), shallow seismic refraction (SSR) and gravity survey (GS), was used to investigate the counter-slope scarps, one of the typical manifestations of the relaxed zones of rock massifs, and the possible initial stages of deep-seated landslides (DSLs). Two upper parts of the extensive DSLs within the Moravskoslezské Beskydy Mountains (Outer Western Carpathians - OWC) built by the sedimentary flysch rock were chosen as the testing sites. A combined geophysical survey on the flysch rocks was performed on both localities to enhance our present findings. The survey revealed that the ERT is able to reliably detect underground discontinuities, which are manifested at the ground surface by one of the typical landforms (tension cracks, trenches, pseudokarst sinkholes, double-crested ridges and counter-slope scarps). Previous studies suggested that bedrock discontinuities should be depicted by high-resistivity features within ERT surveying. According to SSR and GS, expected zones of weakened rock massif were not confirmed directly underneath the superficial landforms, but they were shifted. Based on the SSR and GS measurements, the depicted high-contrast transitions between high- and low-resistivity domains within the ERT profiles were newly identified as possible manifestation of bedrock discontinuities. The results of GPR measurements give only limited information on the sedimentary flysch rocks, due to shallow penetrating depth and locally strong signal attenuation. The combined results of multidisciplinary geophysical surveying confirmed an importance of employing more than one geophysical technique for integrated interpretations of measured data. Integrated interpretations of the measured geophysical data provided a new insight into massif disintegration and the geomorphic origin of the landforms related to the DSL.
Geophysical monitoring in a hydrocarbon reservoir
NASA Astrophysics Data System (ADS)
Caffagni, Enrico; Bokelmann, Goetz
2016-04-01
Extraction of hydrocarbons from reservoirs demands ever-increasing technological effort, and there is need for geophysical monitoring to better understand phenomena occurring within the reservoir. Significant deformation processes happen when man-made stimulation is performed, in combination with effects deriving from the existing natural conditions such as stress regime in situ or pre-existing fracturing. Keeping track of such changes in the reservoir is important, on one hand for improving recovery of hydrocarbons, and on the other hand to assure a safe and proper mode of operation. Monitoring becomes particularly important when hydraulic-fracturing (HF) is used, especially in the form of the much-discussed "fracking". HF is a sophisticated technique that is widely applied in low-porosity geological formations to enhance the production of natural hydrocarbons. In principle, similar HF techniques have been applied in Europe for a long time in conventional reservoirs, and they will probably be intensified in the near future; this suggests an increasing demand in technological development, also for updating and adapting the existing monitoring techniques in applied geophysics. We review currently available geophysical techniques for reservoir monitoring, which appear in the different fields of analysis in reservoirs. First, the properties of the hydrocarbon reservoir are identified; here we consider geophysical monitoring exclusively. The second step is to define the quantities that can be monitored, associated to the properties. We then describe the geophysical monitoring techniques including the oldest ones, namely those in practical usage from 40-50 years ago, and the most recent developments in technology, within distinct groups, according to the application field of analysis in reservoir. This work is performed as part of the FracRisk consortium (www.fracrisk.eu); this project, funded by the Horizon2020 research programme, aims at helping minimize the environmental footprint of the shale-gas exploration and exploitation.
We investigated the geophysical response to subsurface hydrocarbon contamination source removal. Source removal by natural attenuation or by engineered bioremediation is expected to change the biological, chemical, and physical environment associated with the contaminated matrix....
NASA Technical Reports Server (NTRS)
Carr, M. H.; Cassen, P.
1976-01-01
Four areas of investigation, each dealing with the measurement of a particular geophysical property, are discussed. These properties are the gravity field, seismicity, magnetism, and heat flow. All are strongly affected by conditions, past or present, in the planetary interior; their measurement is the primary source of information about planetary interiors.
DOE Office of Scientific and Technical Information (OSTI.GOV)
MYERS DA; RUCKER D; LEVIT M
This report presents the results of the background characterization of the cribs and trenches surrounding the SX tank farm prepared by HydroGEOPHYSICS Inc, Columbia Energy & Environmental Services Inc and Washington River Protection Solutions.
Energy Resources | Alaska Division of Geological & Geophysical Surveys
Alaska MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates Sponsors' Proposals STATEMAP content Energy Resources Additional information Energy Resources Posters and Presentations Gas Hydrates Sponsors' Proposals Energy Resources Staff Projects The Alaska Division of Geological & Geophysical
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pilger, R.H. Jr.
1985-01-01
The report consists of four sections dealing with progress in evaluating geologic, geochemical, and geophysical aspects of geopressured-geothermal energy resources in Louisiana. Separate abstracts have been prepared for the individual sections. (ACR)
BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.
Seeley, Robert L.; Daniels, Jeffrey J.
1984-01-01
A system has been developed to simultaneously sample and transmit digital data from five remote geophysical data receiver stations to a control station that processes, displays, and stores the data. A microprocessor in each remote station receives commands from the control station over a single telemetry channel.
NASA Technical Reports Server (NTRS)
1991-01-01
A compilation of selected bibliographic data specifically relating to recent publications submitted by principal investigators and their associates, supported through the NASA Office of Space Science and Applications, Solar System Exploration Division, Planetary Geology and Geophysics Program is presented.
Publications - GMC 53C | Alaska Division of Geological & Geophysical
Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Paleozoic through Tertiary sandstones, North Slope, Alaska Authors: Alaska Research Associates Publication through Tertiary sandstones, North Slope, Alaska: Alaska Division of Geological & Geophysical Surveys
NASA Technical Reports Server (NTRS)
1990-01-01
This is a compilation of selected bibliographic data specifically relating to recent publications submitted by principle investigators and their associates, supported through the NASA Office of Space Science and Applications, Solar System Exploration Division, Planetary Geology and Geophysics Program.
Publications - AR 2011-A | Alaska Division of Geological & Geophysical
Communications Alaska Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates STATEMAP Program information Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2011-A main
Publications - AR 2010-B | Alaska Division of Geological & Geophysical
Communications Alaska Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates STATEMAP Program information Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2010-B main
Publications - DDS 5 | Alaska Division of Geological & Geophysical Surveys
Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska's Mineral MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates STATEMAP Program information Geologic Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications DDS 5 main content
Publications - MP 146 | Alaska Division of Geological & Geophysical Surveys
Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska's Mineral MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates STATEMAP Program information Geologic Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications MP 146 main content
Publications - MP 159 | Alaska Division of Geological & Geophysical Surveys
Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska's Mineral MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates STATEMAP Program information Geologic Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications MP 159 main content
Publications - AR 2011-B | Alaska Division of Geological & Geophysical
Communications Alaska Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates STATEMAP Program information Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2011-B main
Geophysical investigation of the June 6, 1944 D-Day invasion site at Pointe du Hoc, Normandy, France
NASA Astrophysics Data System (ADS)
Everett, M. E.; Pierce, C. J.; Warden, R. R.; Burt, R. A.
2005-05-01
A near-surface geophysical survey at the D-Day invasion site atop the cliffs at Pointe du Hoc, Normandy, France was carried out using ground-penetrating radar, electromagnetic induction, and magnetic gradiometry equipment. The subsurface targets of investigation are predominantly buried concrete and steel structures and earthworks associated with the German coastal fortifications at this stronpoint of Hitler's Atlantic Wall. The targets are readily detectable embedded within the vadose zone of a weakly magnetic, electrically resistive loess soil cover. The radar and electromagnetic induction responses lend themselves to plan-view imaging of the subsurface, while the magnetics data reveal the presence of buried magnetic bodies in a more subtle fashion. Several intriguing geophysical signatures were discovered, including what may be the buried remains of a railway turntable, ordnance fragments in the bomb craters, a buried steel-reinforced concrete trench, and a linear chain of machine gun firing positins. Geophysical prospecting is shown to be a very powerful tool for historical battlefield characterization.
Bailey, Z.C.; Hanchar, D.W.
1988-01-01
Twenty-four wells were constructed at nine sites at Bear Creek Valley to provide geologic and hydrologic information. Lithologic samples and suits of geophysical logs were obtained from the deepest boreholes at six of the sites. Two of these boreholes at the base of Chestnut Ridge were completed in the Maynardville Limestone and two were completed in the Nolichucky Shale. Two boreholes along Pine Ridge were completed in the Rome Formation. Zones of similar lithology within a borehole were delineated from rock cutting refined by examination of geophysical logs. The contact between the Maynardville Limestone and Nolichucky Shale was identified in two of the boreholes. Fractures and cavities were readily identifiable on the acoustic-televiewer and caliper logs. Distinct water-bearing intervals were also identified from the temperature, fluid resistance, and resistivity logs. Depths at which the drilling encounterd a thrust were identified in two boreholes in the Rome Formation from both rock cutting and geophysical logs. (USGS)
Stanley, W.D.; Blakely, R.J.
1995-01-01
The Geysers-Clear Lake geothermal area encompasses a large dry-steam production area in The Geysers field and a documented high-temperature, high-pressure, water-dominated system in the area largely south of Clear Lake, which has not been developed. An updated view is presented of the geological/geophysical complexities of the crust in this region in order to address key unanswered questions about the heat source and tectonics. Forward modeling, multidimensional inversions, and ideal body analysis of the gravity data, new electromagnetic sounding models, and arguments made from other geophysical data sets suggest that many of the geophysical anomalies have significant contributions from rock property and physical state variations in the upper 7 km and not from "magma' at greater depths. Regional tectonic and magmatic processes are analyzed to develop an updated scenario for pluton emplacement that differs substantially from earlier interpretations. In addition, a rationale is outlined for future exploration for geothermal resources in The Geysers-Clear Lake area. -from Authors
``Recycling'' Geophysics: Monitoring and Isotopic Analysis of Engineered Biological Systems
NASA Astrophysics Data System (ADS)
Doherty, R.; Singh, K. P.; Ogle, N.; Ntarlagiannis, D.
2010-12-01
The emerging sub discipline of biogeophysics has provoked debate on the mechanisms of microbial processes that may contribute to geophysical signatures. At field scales geophysical signatures are often non unique due to the many parameters (physical, chemical, and biological) that are involved. It may be easier to apply geophysical techniques such as electrodic potential (EP), self potential (SP) and induced polarization (IP) to engineered biological systems where there is a degree of control over the design of the physical and chemical domain. Here we present results of a column experiment that was designed to anaerobically biodegrade dissolved organic matter in landfill leachate. The column utilises a recycled porous media (concrete) to help sequester organic carbon. Electrodic potential, self potential and induced polarisation are used in conjunction with chemical and isotopic techniques to monitor the effectiveness of this approach. Preliminary carbon and oxygen isotopic analysis on concrete from the column in contact with leachate show isotopic enrichment suggesting abiotic precipitation of carbonates.
Ellefsen, K.J.; Burton, B.L.; Lucius, J.E.; Haines, S.S.; Fitterman, D.V.; Witty, J.A.; Carlson, D.; Milburn, B.; Langer, W.H.
2007-01-01
Personnel from the U.S. Geological Survey and Martin Marietta Aggregates, Inc., conducted field demonstrations of five different geophysical methods to show how these methods could be used to characterize deposits of alluvial aggregate. The methods were time-domain electromagnetic sounding, electrical resistivity profiling, S-wave reflection profiling, S-wave refraction profiling, and P-wave refraction profiling. All demonstrations were conducted at one site within a river valley in central Indiana, where the stratigraphy consisted of 1 to 2 meters of clay-rich soil, 20 to 35 meters of alluvial sand and gravel, 1 to 6 meters of clay, and multiple layers of limestone and dolomite bedrock. All geophysical methods, except time-domain electromagnetic sounding, provided information about the alluvial aggregate that was consistent with the known geology. Although time-domain electromagnetic sounding did not work well at this site, it has worked well at other sites with different geology. All of these geophysical methods complement traditional methods of geologic characterization such as drilling.
Study of Shallow Low-Enthalpy Geothermal Resources Using Integrated Geophysical Methods
NASA Astrophysics Data System (ADS)
De Giorgi, Lara; Leucci, Giovanni
2015-02-01
The paper is focused on low enthalpy geothermal exploration performed in south Italy and provides an integrated presentation of geological, hydrogeological, and geophysical surveys carried out in the area of municipality of Lecce. Geological and hydrogeological models were performed using the stratigraphical data from 51 wells. A ground-water flow (direction and velocity) model was obtained. Using the same wells data, the ground-water annual temperature was modeled. Furthermore, the ground surface temperature records from ten meteorological stations were studied. This allowed us to obtain a model related to the variations of the temperature at different depths in the subsoil. Integrated geophysical surveys were carried out in order to explore the low-enthalpy geothermal fluids and to evaluate the results of the model. Electrical resistivity tomography (ERT) and self-potential (SP) methods were used. The results obtained upon integrating the geophysical data with the models show a low-enthalpy geothermal resource constituted by a shallow ground-water system.
Low, Dennis J.; Conger, Randall W.
2001-01-01
Between February 1996 and November 2000, geophysical logging was conducted in 27 open borehole wells in and adjacent to the Butz Landfill Superfund Site, Jackson Township, Monroe County, Pa., to determine casing depth and depths of water-producing zones, water-receiving zones, and zones of vertical borehole flow. The wells range in depth from 57 to 319 feet below land surface. The geophysical logging determined the placement of well screens and packers, which allow monitoring and sampling of water-bearing zones in the fractured bedrock so that the horizontal and vertical distribution of contaminated ground water migrating from known sources could be determined. Geophysical logging included collection of caliper, natural-gamma, single-point-resistance, fluid-resistivity, fluid-temperature, and video logs. Caliper and video logs were used to locate fractures, joints, and weathered zones. Inflections on single-point-resistance, fluid-temperature, and fluid-resistivity logs indicated possible water-bearing fractures, and heatpulse-flowmeter measurements verified these locations. Natural-gamma logs provided information on stratigraphy.
Geophysical examination of coal deposits
NASA Astrophysics Data System (ADS)
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.
An analysis of the lithology to resistivity relationships using airborne EM and boreholes
NASA Astrophysics Data System (ADS)
Barfod, Adrian A. S.; Christiansen, Anders V.; Møller, Ingelise
2014-05-01
We present a study of the relationship between dense airborne SkyTEM resistivity data and sparse lithological borehole data. Understanding the geological structures of the subsurface is of great importance to hydrogeological surveys. Large scale geological information can be gathered directly from boreholes or indirectly from large geophysical surveys. Borehole data provides detailed lithological information only at the position of the borehole and, due to the sparse nature of boreholes, they rarely provide sufficient information needed for high-accuracy groundwater models. Airborne geophysical data, on the other hand, provide dense spatial coverage, but are only indirectly bearing information on lithology through the resistivity models. Hitherherto, the integration of the geophysical data into geological and hydrogeological models has been often subjective, largely un-documented and painstakingly manual. This project presents a detailed study of the relationships between resistivity data and lithological borehole data. The purpose is to objectively describe the relationships between lithology and geophysical parameters and to document these relationships. This project has focused on utilizing preexisting datasets from the Danish national borehole database (JUPITER) and national geophysical database (GERDA). The study presented here is from the Norsminde catchment area (208 sq. km), situated in the municipality of Odder, Denmark. The Norsminde area contains a total of 758 boreholes and 106,770 SkyTEM soundings. The large amounts of data make the Norsminde area ideal for studying the relationship between geophysical data and lithological data. The subsurface is discretized into 20 cm horizontal sampling intervals from the highest elevation point to the depth of the deepest borehole. For each of these intervals a resistivity value is calculated at the position of the boreholes using a kriging formulation. The lithology data from the boreholes are then used to categorize the interpolated resistivity values according to lithology. The end result of this comparison is resistivity distributions for different lithology categories. The distributions provide detailed objective information of the resistivity properties of the subsurface and are a documentation of the resistivity imaging of the geological lithologies. We show that different lithologies are mapped at distinctively different resistivities but also that the geophysical inversion strategies influences the resulting distributions significantly.
NASA Astrophysics Data System (ADS)
Bernard, J.
2012-12-01
The Manufacturers of geophysical instruments have been facing these past decades the fast evolution of the electronics and of the computer sciences. More automatisms have been introduced into the equipment and into the processing and interpretation software which may let believe that conducting geophysical surveys requires less understanding of the method and less experience than in the past. Hence some misunderstandings in the skills that are needed to make the geophysical results well integrated among the global information which the applied geologist needs to acquire to be successful in his applications. Globally, the demand in geophysical investigation goes towards more penetration depth, requiring more powerful transmitters, and towards a better resolution, requiring more data such as in 3D analysis. Budgets aspects strongly suggest a high efficiency in the field associated to high speed data processing. The innovation is required in all aspects of geophysics to fit with the market needs, including new technological (instruments, software) and methodological (methods, procedures, arrays) developments. The structures in charge of the geophysical work can be public organisations (institutes, ministries, geological surveys,…) or can come from the private sector (large companies, sub-contractors, consultants, …), each one of them getting their own constraints in the field work and in the processing and interpretation phases. In the applications concerning Groundwater investigations, Mining Exploration, Environmental and Engineering surveys, examples of data and their interpretation presently carried out all around the world will be presented for DC Resistivity (Vertical Electrical Sounding, 2D, 3D Resistivity Imaging, Resistivity Monitoring), Induced Polarisation (Time Domain 2D, 3D arrays for mining and environmental), Magnetic Resonance Sounding (direct detection and characterisation of groundwater) and Electromagnetic (multi-component and multi-spacing Frequency Domain Sounding and Profiling technique). The place that Geophysics takes in the market among the other investigation techniques is, and will remain, dependant on the quality of the results obtained, despite the uncertainties linked to the field (noise aspects) and to the interpretation (equivalence aspects), under the control of budget decisions.Resistivity Imaging measurements for groundwater investigations
Geophysical methods for road construction and maintenance
NASA Astrophysics Data System (ADS)
Rasul, Hedi; Karlson, Caroline; Jamali, Imran; Earon, Robert; Olofsson, Bo
2015-04-01
Infrastructure, such as road transportation, is a vital in civilized societies; which need to be constructed and maintained regularly. A large part of the project cost is attributed to subsurface conditions, where unsatisfactory conditions could increase either the geotechnical stabilization measures needed or the design cost itself. A way to collect information of the subsurface and existing installations which can lead to measures reducing the project cost and damage is to use geophysical methods during planning, construction and maintenance phases. The moisture in road layers is an important factor, which will affect the bearing capacity of the construction as well as the maintenances. Moisture in the road is a key factor for a well-functioning road. On the other hand the excessive moisture is the main reason of road failure and problems. From a hydrological point of view geophysical methods could help road planners identify the water table, geological strata, pollution arising from the road and the movement of the pollution before, during and after construction. Geophysical methods also allow road planners to collect valuable data for a large area without intrusive investigations such as with boreholes, i.e. minimizing the environmental stresses and costs. However, it is important to specify the investigation site and to choose the most appropriate geophysical method based on the site chosen and the objective of the investigation. Currently, numerous construction and rehabilitation projects are taking places around the world. Many of these projects are focused on infrastructural development, comprising both new projects and expansion of the existing infrastructural network. Geophysical methods can benefit these projects greatly during all phases. During the construction phase Ground Penetrating radar (GPR) is very useful in combination with Electrical Resistivity (ER) for detecting soil water content and base course compaction. However, ER and Electromagnetic (EM) methods can also be used for monitoring changes in water content and pollutant spreading during the maintenance phase. The objective of this study was to describe various geophysical methods which could benefit the road planning, construction and maintenance phases focusing on hydrological impacts.
This dataset provides all data used to generate the figures and tables in the article entitled Particulate matter and black carbon optical properties and emission factors from prescribed fires in the southeastern United States published in the Journal of Geophysical Research: AtmospheresThis dataset is associated with the following publication:Holder , A., G. Hagler , J. Aurell, M. Hays , and B. Gullett. Particulate matter and black carbon optical properties and emission factors from prescribed fires in the southeastern United States. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES. American Geophysical Union, Washington, DC, USA, 121(7): 3465-3483, (2016).
Let's be sure to do our homework
NASA Astrophysics Data System (ADS)
Grew, Priscilla C.
A strong federal budget for geophysical research requires the active support of Congress. AGU needs to raise the general level of awareness among members of key congressional committees and their staffs of the importance of geophysical phenomena to society and the contributions geophysicists can make in providing scientific information as an ingredient in the formulation of public policy.Effective communication with any legislative body, be it a state legislature or Congress, requires long-term repeated contact—not just a sudden appearance at the final stage of a budget deliberation or during a crisis when some geophysical event like a catastrophic earthquake or volcanic eruption captures the attention of legislators.
John, David A.; Nash, J.T.; Plouff, Donald; Whitebread, D.H.
1991-01-01
The Tonopah 1 ? by 2 ? quadrangle in south-central Nevada was studied by an interdisciplinary research team to appraise its mineral resources. The appraisal is based on geological, geochemical, and geophysical field and laboratory investigations, the results of which are published as a folio of maps, figures, and tables, with accompanying discussions. This circular provides background information on the investigations and integrates the information presented in the folio. The selected bibliography lists references to the geology, geochemistry, geophysics, and mineral deposits of the Tonopah 1 ? by 2 ? quadrangle.
Geophysical abstracts 167, October-December 1956
Rabbitt, Mary C.; Vitaliano, Dorothy B.; Vesselowsky, S.T.; ,
1956-01-01
Geophysical Abstracts includes abstracts of technical papers and books on the physics of the solid earth, the application of physical methods and techniques to geologic problems, and geophysical exploration. The table of contents, which is alphabetically arranged, shows the material covered.Abstracts are prepared only of material that is believed to be generally available. Ordinarily abstracts are not published of material with limited circulation (such as dissertations, open-file reports, or memoranda) or of other papers presented orally at meetings unless summaries of substantial length are published. Abstracts of papers in Japanese and Chinese are based on abstracts or summaries in a western language accompanying the paper.
Geophysical abstracts 164, January-March 1956
Rabbitt, Mary C.; Vitaliano, Dorothy B.; Vesselowsky, S.T.; ,
1956-01-01
Geophysical Abstracts includes abstracts of technical papers and books on the physics of the solid earth, the application of physical methods and techniques to geologic problems, and geophysical exploration. A new table of contents, alphabetically arranged, has been adapted to show more clearly the material covered.Abstracts are prepared only of material that is believed to be generally available. Ordinarily abstracts are not published of material with limited circulation (such as dissertations, open-file reports, or memoranda) or of papers presented orally at meetings unless summaries of substantial length are published. Abstracts of papers in Japanese and Chinese are based on abstracts or summaries in a western language accompanying the paper.
Geophysical abstracts 166, July-September 1956
Rabbitt, Mary C.; Vitaliano, Dorothy B.; Vesselowsky, S.T.; ,
1956-01-01
Geophysical Abstracts includes abstracts of technical papers and books on the physics of the solid earth, the application of physical methods and techniques to geologic problems, and geophysical exploration. The table of contents, which is alphabetically arranged, shows the material covered.Abstracts are prepared only of material that is believed to be generally available. Ordinarily abstracts are not published of material with limited circulation (such as dissertations, open-file reports, or memoranda) or of other papers presented orally at meetings unless summaries of substantial length are published. Abstracts of papers in Japanese and Chinese are based on abstracts or summaries in a western language accompanying the paper.
Geophysical abstracts 165, April-June 1956
Rabbitt, Mary C.; Vitaliano, Dorothy B.; Vesselowsky, S.T.; ,
1956-01-01
Geophysical Abstracts includes abstracts of technical papers and books on the physics of the solid earth, the application of physical methods and techniques to geologic problems, and geophysical exploration. The table of contents, which is alphabetically arranged, shows the material covered.Abstracts are prepared only of material that is believed to be generally available. Ordinarily abstracts are not published of material with limited circulation (such as dissertations, open-file reports, or memoranda) or of other papers presented orally at meetings unless summaries of substantial length are published. Abstracts of papers in Japanese and Chinese are based on abstracts or summaries in a western language accompanying the paper.
Publications of the Volcano Hazards Program 2010
Nathenson, Manuel
2012-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Manoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. Only published papers and maps are included here; numerous abstracts presented at scientific meetings are omitted. Publication dates are based on year of issue, with no attempt to assign them to fiscal year.
Publications of the Volcano Hazards Program 2012
Nathenson, Manuel
2014-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity, as funded by Congressional appropriation. Investigations are carried out by the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Manoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all of these institutions. Only published papers and maps are included here; abstracts presented at scientific meetings are omitted. Publication dates are based on year of issue, with no attempt to assign them to a fiscal year.
Publications of the Volcano Hazards Program 2009
Nathenson, Manuel
2011-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by congressional appropriation. Investigations are carried out in the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Manoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. Only published papers and maps are included here; numerous abstracts presented at scientific meetings are omitted. Publications dates are based on year of issue, with no attempt to assign them to fiscal year.
Publications of Volcano Hazards Program 2000
Nathenson, Manuel
2001-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Publications of the Volcano Hazards Program 1997
Nathenson, Manuel
1998-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geologic and Water Resources Divisions of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Geophysical Research Letters: New policies improve top-cited geosciences journal
Calais, Eric; Diffenbaugh, Noah; D'Odorico, Paolo; Harris, Ruth; Knorr, Wolfgang; Lavraud, Benoit; Mueller, Anne; Peterson, William; Rignot, Eric; Srokosz, Meric; Strutton, Peter; Tyndall, Geoff; Wysession, Michael; Williams, Paul
2010-01-01
Geophysical Research Letters (GRL) is the American Geophysical Union's premier journal of fast, groundbreaking communication. It rapidly publishes high- impact,letter-length articles, and it is the top-cited multidisciplinary geosciences journal over the past 10 years, with an impact factor that increased again in 2009, to 3.204. For manuscripts submitted to GRL, the median time to first and final decision is 23 and 27 days, respectively—a 35% improvement since 2007—and the median time from submission to publication is 13 weeks for 90% of GRL papers—a 25% improvement since 2007. Among high-impact publications in the geosciences, GRL has the fastest turnaround.
43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?
Code of Federal Regulations, 2011 CFR
2011-10-01
..., geochemical, or geophysical surveys? (a) Geological surveys are surveys of the geology of mineral deposits. These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ANNUAL...
43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?
Code of Federal Regulations, 2012 CFR
2012-10-01
..., geochemical, or geophysical surveys? (a) Geological surveys are surveys of the geology of mineral deposits. These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ANNUAL...
43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?
Code of Federal Regulations, 2014 CFR
2014-10-01
..., geochemical, or geophysical surveys? (a) Geological surveys are surveys of the geology of mineral deposits. These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ANNUAL...
43 CFR 3836.13 - What are geological, geochemical, or geophysical surveys?
Code of Federal Regulations, 2013 CFR
2013-10-01
..., geochemical, or geophysical surveys? (a) Geological surveys are surveys of the geology of mineral deposits. These are done by, among other things, taking mineral samples, mapping rock units, mapping structures... (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ANNUAL...
43 CFR 3481.3 - Confidentiality.
Code of Federal Regulations, 2011 CFR
2011-10-01
... part or part 3400 of this title shall be open for public inspection and copying during regular office... geologic and geophysical data and maps pertaining to Federal recoverable coal reserves obtained from...)), such as geologic and geophysical data and maps, shall not be available for public inspection or made...
Geophysics of an Oceanic Ice Shell on Snowball Earth
NASA Technical Reports Server (NTRS)
Gaidos, E. J.
2000-01-01
Kirschvink proposed Precambrian low-latitude glaciation could result in an albedo-driven catastrophic runaway to a "Snowball Earth" state in which pack ice up to 1 km thick covered the world ocean. The geophysical state of an ice crust on a Snowball Earth is examined.
43 CFR 3481.3 - Confidentiality.
Code of Federal Regulations, 2014 CFR
2014-10-01
... part or part 3400 of this title shall be open for public inspection and copying during regular office... geologic and geophysical data and maps pertaining to Federal recoverable coal reserves obtained from...)), such as geologic and geophysical data and maps, shall not be available for public inspection or made...
43 CFR 3481.3 - Confidentiality.
Code of Federal Regulations, 2013 CFR
2013-10-01
... part or part 3400 of this title shall be open for public inspection and copying during regular office... geologic and geophysical data and maps pertaining to Federal recoverable coal reserves obtained from...)), such as geologic and geophysical data and maps, shall not be available for public inspection or made...
43 CFR 3481.3 - Confidentiality.
Code of Federal Regulations, 2012 CFR
2012-10-01
... part or part 3400 of this title shall be open for public inspection and copying during regular office... geologic and geophysical data and maps pertaining to Federal recoverable coal reserves obtained from...)), such as geologic and geophysical data and maps, shall not be available for public inspection or made...
Links | Alaska Division of Geological & Geophysical Surveys
Alaska MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates Sponsors' Proposals STATEMAP . National Geothermal Data System (NGDS) The National Geothermal Data System (NGDS) is a catalog of documents and datasets that provide information about geothermal resources. Geophysical Institute Seismology
Publications - GMC 267 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a well materials Authors: Unknown Publication Date: 1996 Publisher: Alaska Division of Geological & Alaska North Slope well materials: Alaska Division of Geological & Geophysical Surveys Geologic
DOT National Transportation Integrated Search
2003-06-01
This document discusses the results of geophysical investigation methods conducted along : Interstate Route 70 (IR-70) under a contract with the Ohio Department of Transportation : (ODOT). The specific site conditions, as determined by the investigat...
Contractors are cautiously optimistic
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stremel, K.
1984-10-01
Anticipating stable crew counts and marginal increases in operator exploration budgets, geophysical contractors are cautiously optimistic about continued industry growth. Most companies are operating on lean profits, and more business consolidations are expected as the market gradually rebounds. Prospects for an upturn in geophysical operations by oil companies are discussed.
Publications - GMC 57 | Alaska Division of Geological & Geophysical Surveys
from the Standard Oil Company of California Nimiuk Pt. #1 well Authors: Leverson, John, and American Stratigraphic Company Publication Date: 1977 Publisher: Alaska Division of Geological & Geophysical Surveys information. Bibliographic Reference Leverson, John, and American Stratigraphic Company, 1977, A mineral
Publications - GMC 292 | Alaska Division of Geological & Geophysical
and core chips (13760'-13820') of Union Oil Company of California Clam Gulch Unit #1 Authors: Marathon Oil Company Publication Date: 2000 Publisher: Alaska Division of Geological & Geophysical Surveys information. Bibliographic Reference Marathon Oil Company, 2000, Hydrocarbon extraction gas chromatograph
Reconnaissance Geologic Map of the Duncan Canal-Zarembo Island Area, Southeastern Alaska
Karl, Susan M.; Haeussler, Peter J.; McCafferty, Anne E.
1999-01-01
The geologic map of the Duncan Canal-Zarembo Island area is the result of a multidisciplinary investigation of an area where an airborne geophysical survey was flown in the spring of 1997. The area was chosen for the geophysical survey because of its high mineral potential, a conclusion of the Petersburg Mineral Resource Assessment Project, conducted by the U.S. Geological Survey from 1978 to 1982. The City of Wrangell, in southeastern Alaska, the Bureau of Land Management, and the State of Alaska provided funding for the airborne geophysical survey. The geophysical data from the airborne survey were released in September 1997. The U.S. Geological Survey conducted field investigations in the spring and fall of 1998 to identify and understand the sources of the geophysical anomalies from the airborne survey. This geologic map updates the geologic maps of the same area published by David A. Brew at 1:63,360 (Brew, 1997a-m; Brew and Koch, 1997). This update is based on 3 weeks of field work, new fossil collections, and the geophysical maps released by the State of Alaska ( DGGS, Staff, and others, 1997a-o). Geologic data from outcrops, fossil ages, radiometric ages, and geochemical signatures were used to identify lithostratigraphic units. Where exposure is poor, geophysical characteristics were used to help control the boundaries of these units. No unit boundaries were drawn based on geophysics alone. The 7200 Hertz resistivity maps (DGGS, Staff, and others, 1997k-o) were particularly helpful for controlling unit boundaries, because different stratigraphic units have distinctive characteristic conductive signatures (Karl and others, 1998). Increased knowledge of unit ages, unit structure, and unit distribution, led to improved understanding of the nature of unit contacts. Northwest- to southwest-directed thrust faults, particularly on Kupreanof Island, are new discovery. Truncated faults and map patterns suggest there were at least 2 generations of thrusting, and that the thrust faults have been folded. Subsequent right-lateral strike-slip NW-SE faults, have offset thrust faults, and these in turn are offset by N-S right-lateral strike-slip faults. Our fieldwork raised as many questions as it answered, and we see this map as a progress report at a reconnaissance level. The main contributions of this map are 1) the greater distribution of Triassic rocks, 2) increased fossil age information, and 3) the identification of thrust faults within and between units.
Jorgensen, Donald G.; Petricola, Mario
1994-01-01
A program of borehole-geophysical logging was implemented to supply geologic and geohydrologic information for a regional ground-water investigation of Abu Dhabi Emirate. Analysis of geophysical logs was essential to provide information on geohydrologic properties because drill cuttings were not always adequate to define lithologic boundaries. The standard suite of logs obtained at most project test holes consisted of caliper, spontaneous potential, gamma ray, dual induction, microresistivity, compensated neutron, compensated density, and compensated sonic. Ophiolitic detritus from the nearby Oman Mountains has unusual petrophysical properties that complicated the interpretation of geophysical logs. The density of coarse ophiolitic detritus is typically greater than 3.0 grams per cubic centimeter, porosity values are large, often exceeding 45 percent, and the clay fraction included unusual clays, such as lizardite. Neither the spontaneous-potential log nor the natural gamma-ray log were useable clay indicators. Because intrinsic permeability is a function of clay content, additional research in determining clay content was critical. A research program of geophysical logging was conducted to determine the petrophysical properties of the shallow subsurface formations. The logging included spectral-gamma and thermal-decay-time logs. These logs, along with the standard geophysical logs, were correlated to mineralogy and whole-rock chemistry as determined from sidewall cores. Thus, interpretation of lithology and fluids was accomplished. Permeability and specific yield were calculated from geophysical-log data and correlated to results from an aquifer test. On the basis of results from the research logging, a method of lithologic and water-resistivity interpretation was developed for the test holes at which the standard suite of logs were obtained. In addition, a computer program was developed to assist in the analysis of log data. Geohydrologic properties were estimated, including volume of clay matrix, volume of matrix other than clay, density of matrix other than clay, density of matrix, intrinsic permeability, specific yield, and specific storage. Geophysical logs were used to (1) determine lithology, (2) correlate lithologic and permeable zones, (3) calibrate seismic reprocessing, (4) calibrate transient-electromagnetic surveys, and (5) calibrate uphole-survey interpretations. Logs were used at the drill site to (1) determine permeability zones, (2) determine dissolved-solids content, which is a function of water resistivity, and (3) design wells accordingly. Data and properties derived from logs were used to determine transmissivity and specific yield of aquifer materials.
Evidence for a critical Earth: the New Geophysics
NASA Astrophysics Data System (ADS)
Crampin, Stuart; Gao, Yuan
2015-04-01
Phenomena that are critical-systems verging on criticality with 'butterfly wings' sensitivity are common - the weather, climate change; stellar radiation; the New York Stock Exchange; population explosions; population collapses; the life cycle of fruit-flies; and many more. It must be expected that the Earth, an archetypal complex heterogeneous interactive phenomena, is a critical-system, hence there is a New Geophysics imposing fundamentally new properties on conventional sub-critical geophysics. We shall show that, despite shear waves and shear-wave splitting (SWS) being observationally neglected, azimuthally-varying stress-aligned SWS is nearly universally observed throughout the Earth's crust and uppermost ~400km of the mantle. Caused by stress-aligned fluid-saturated microcracks (intergranular films of hydrolysed melt in the mantle), the microcracks are so closely-spaced that they verge on failure in fracturing and earthquakes. Phenomena that verge on failure in this way are critical-systems which impose a range of fundamental-new properties on conventional sub-critical geophysics including: self-similarity; monitorability; calculability; predictability; controllability; universality; and butterfly wings' sensitivity. We shall show how these phenomena have been consistently observed along millions of source-to-receiver ray paths confirming the New Geophysics. New Geophysics helps to explain many otherwise inexplicable observations including a number of geophysical conundrums such as the Gutenberg-Richter relationship which is used to describe the behaviour of conventional classic geophysics despite being massively non-linear. The great advantage of the critical Earth is that, unlike other critical-systems, the progress towards criticality can be monitored at almost any point within the deep interior of the material, by analysing observations of seismic SWS. This gives an unrivalled understanding of the detailed behaviour of a particular critical-system. This new understanding of fluid-rock deformation unifies much of the behaviour and has currently-relevant applications: 1) The times, magnitudes, and in some circumstances locations, of impending earthquakes can be stress-forecast (predicted); 2) The times of impending volcanic eruptions can be stress-forecast (predicted); 3) The production of hydrocarbon reservoirs can be, in principle, calculated; 4) Recovery from hydrocarbon reservoirs will be increased if production is slower; 5) Time-lapse of SWS single-well imaging can monitor movement of oil/water contacts; 6) Time-lapse of SWS can monitor behaviour of fluids in fracking reservoirs; 7) Time-lapse SWS can monitor leakage in underground nuclear-waste repositories. Papers referring to these developments can be found in geos.ed.ac.uk/home/scrampin/opinion. Also see abstracts in EGU2015 Sessions: Gao & Crampin (SM3.1), Liu & Crampin (NH2.5), and Crampin & Gao (GD.1).
Location and characterization of the Sancti Spiritus Fort from geophysical investigations
NASA Astrophysics Data System (ADS)
Bonomo, Néstor; Osella, Ana; Martinelli, Patricia; la Vega, Matías de; Cocco, Gabriel; Letieri, Fabian; Frittegotto, Guillermo
2012-08-01
A geophysical investigation was carried out to locate and characterize the remains of the Sancti Spiritus Fort, the first European settlement in the South Cone of America (1527-1529). In an initial stage, we used three complementary methods, ground penetrating radar, multifrequency electromagnetic induction and dipole-dipole electric profiling, to increase the possibility of detecting the structures of the Fort whose physical properties were expected to be similar to those of the surrounding soil, as they were constructed with raw earth probably extracted from it. From different views of the data, a number of electromagnetic signals apparently related to these structures were identified. Test excavations confirmed these hypotheses and showed that the structures were poorly preserved. Furthermore, they were almost indistinguishable through direct inspection of the excavated sections of soil, and very difficult to track. Therefore, in a second stage of geophysical studies, we acquired high-density grids of GPR data at relevant areas, looking for more detailed information about the structures. The results of these studies allowed to determine with precision their continuity through the site and also to interpret a number of areas which had remained unclear from the first survey. Extensive archaeological excavations were designed from the geophysical maps and carried out. From them, the geophysical interpretations were fully confirmed, and the presence of structural elements of previous and later native settlements was established.
NASA Astrophysics Data System (ADS)
Soupios, P. M.; Loupasakis, C.; Vallianatos, F.
2008-06-01
Nowadays, geophysical prospecting is implemented in order to resolve a diversity of geological, hydrogeological, environmental and geotechnical problems. Although plenty of applications and a lot of research have been conducted in the countryside, only a few cases have been reported in the literature concerning urban areas, mainly due to high levels of noise present that aggravate most of the geophysical methods or due to spatial limitations that hinder normal method implementation. Among all geophysical methods, electrical resistivity tomography has proven to be a rapid technique and the most robust with regard to urban noise. This work presents a case study in the urban area of Chania (Crete Island, Greece), where electrical resistivity tomography (ERT) has been applied for the detection and identification of possible buried ancient ruins or other man-made structures, prior to the construction of a building. The results of the detailed geophysical survey indicated eight areas of interest providing resistivity anomalies. Those anomalies were analysed and interpreted combining the resistivity readings with the geotechnical borehole data and the historical bibliographic reports—referring to the 1940s (Xalkiadakis 1997 Industrial Archaeology in Chania Territory pp 51-62). The collected ERT-data were processed by applying advanced algorithms in order to obtain a 3D-model of the study area that depicts the interesting subsurface structures more clearly and accurately.
Airborne Gravity Survey and Ground Gravity in Afghanistan: A Website for Distribution of Data
Abraham, Jared D.; Anderson, Eric D.; Drenth, Benjamin J.; Finn, Carol A.; Kucks, Robert P.; Lindsay, Charles R.; Phillips, Jeffrey D.; Sweeney, Ronald E.
2008-01-01
Afghanistan?s geologic setting suggests significant natural resource potential. Although important mineral deposits and petroleum resources have been identified, much of the country?s potential remains unknown. Airborne geophysical surveys are a well- accepted and cost-effective method for remotely obtaining information of the geological setting of an area. A regional airborne geophysical survey was proposed due to the security situation and the large areas of Afghanistan that have not been covered using geophysical exploration methods. Acting upon the request of the Islamic Republic of Afghanistan Ministry of Mines, the U.S. Geological Survey contracted with the U.S. Naval Research Laboratory to jointly conduct an airborne geophysical and remote sensing survey of Afghanistan. Data collected during this survey will provide basic information for mineral and petroleum exploration studies that are important for the economic development of Afghanistan. Additionally, use of these data is broadly applicable in the assessment of water resources and natural hazards, the inventory and planning of civil infrastructure and agricultural resources, and the construction of detailed maps. The U.S. Geological Survey is currently working in cooperation with the U.S. Agency of International Development to conduct resource assessments of the country of Afghanistan for mineral, energy, coal, and water resources, and to assess geologic hazards. These geophysical and remote sensing data will be used directly in the resource and hazard assessments.
NASA Astrophysics Data System (ADS)
Afonso, Juan Carlos; Zlotnik, Sergio; Díez, Pedro
2015-10-01
We present a flexible, general, and efficient approach for implementing thermodynamic phase equilibria information (in the form of sets of physical parameters) into geophysical and geodynamic studies. The approach is based on Tensor Rank Decomposition methods, which transform the original multidimensional discrete information into a separated representation that contains significantly fewer terms, thus drastically reducing the amount of information to be stored in memory during a numerical simulation or geophysical inversion. Accordingly, the amount and resolution of the thermodynamic information that can be used in a simulation or inversion increases substantially. In addition, the method is independent of the actual software used to obtain the primary thermodynamic information, and therefore, it can be used in conjunction with any thermodynamic modeling program and/or database. Also, the errors associated with the decomposition procedure are readily controlled by the user, depending on her/his actual needs (e.g., preliminary runs versus full resolution runs). We illustrate the benefits, generality, and applicability of our approach with several examples of practical interest for both geodynamic modeling and geophysical inversion/modeling. Our results demonstrate that the proposed method is a competitive and attractive candidate for implementing thermodynamic constraints into a broad range of geophysical and geodynamic studies. MATLAB implementations of the method and examples are provided as supporting information and can be downloaded from the journal's website.
NASA Astrophysics Data System (ADS)
Butler, D. K.
1982-03-01
This report reviews the scope of a research effort initiated in 1974 at the U.S. Army Engineer Waterways Experiment Station with the objectives of (a) assessing the state of the art in geophysical cavity detection and delineation methodology and (b) developing new methods and improving or adapting old methods for application to cavity detection and delineation. Two field test sites were selected: (a) the Medford Cave site with a relatively shallow (10- to 50-ft-deep) air-filled cavity system and (b) the Manatee Springs site with a deeper (approximately 100-ft-deep) water-filled cavity system. Results of field studies at the Medford Cave site are presented in this report: (a) the site geology, (b) the site topographic survey, (c) the site drilling program (boreholes for geophysical tests, for determination of a detailed geological cross section, and for verification of geophysical anomalies), (d) details of magnetic and microgravimetric surveys, and (e) correlation of geophysical results with known site geology. Qualitative interpretation guidelines using complementary geophysical techniques for site investigations in karst regions are presented. Including the results of electrical resistivity surveys conducted at the Medford Cave site, the qualitative guidelines are applied to four profile lines, and drilling locations are indicated on the profile plots of gravity, magnetic, and electrical resistivity data. Borehole logs are then presented for comparison with the predictions of the qualitative interpretation guidelines.
NASA Astrophysics Data System (ADS)
Danov, Dimitar
2008-02-01
The statistical field-aligned current (FAC) distribution has been demonstrated by [Iijima, T., Potemra, T.A., 1976. The amplitude distribution of field-aligned currents at northern high latitudes observed by Triad. Journal of Geophysical Research 81(13), 2165-2174] and many other authors. The large-scale (LS) FACs have been described by different empirical/statistical models [Feldstein, Ya. I., Levitin, A.E., 1986. Solar wind control of electric fields and currents in the ionosphere. Journal of Geomagnetism and Geoelectricity 38, 1143; Papitashvili, V.O., Rich, F.J., Heinemann, M.A., Hairston, M.R., 1999. Parameterization of the Defense Meteorological Satellite Program ionospheric electrostatic potentials by the interplanetary magnetic field strength and direction. Journal of Geophysical Research 104, 177-184; Papitashvili, V.O., Christiansen, F., Neubert, T., 2002. A new model of field-aligned currents derived from high-precision satellite magnetic field data. Geophysical Research Letters, 29(14), 1683, doi:10.1029/2001GL014207; Tsyganenko, N.A., 2001. A model of the near magnetosphere with a dawn-dusk asymetry (I. Mathematical structure). Journal of Geophysical Research 107(A8), doi:10.1029/2001JA000219; Weimer, D.R., 1996a. A new model for prediction of ionospheric electric potentials as a function of the IMF. In: Snowmass'96 Online Poster Session; Weimer, D.R., 1996b. Substorm influence on the ionospheric convection patterns. In: Snowmass'96 Online Poster Session; Weimer, D.R., 2001. Maps of ionospheric field-aligned currents as a function of the interplanetary magnetic field derived from Dynamic Explorer 2 data. Journal of Geophysical Research 106, 12,889-12,902; Weimer, D.R., 2005. Improved ionospheric electrodynamic models and application to calculating Joule heating rates. Journal of Geophysical Research 110, A05306, doi:10.1029/2004JA010884]. In the present work, we compare two cases of LS FAC obtained from magnetic field measurements onboard the Intercosmos Bulgaria-1300 satellite with three models: two empirical [Tsyganenko, N.A., 2001. A model of the near magnetosphere with a down-dusk asymetry (I. Mathematical structure). Journal of Geophysical Research 107(A8), doi:10.1029/2001JA000219; Weimer, D.R., 2005. Improved ionospheric electrodynamic models and application to calculating Joule heating rates. Journal of Geophysical Research 110, A05306, doi:10.1029/2004JA010884] and one computer-based MHD-simulation in "The Community Coordinated Modeling Center" (CCMC) [Toth, G., et al., 2005. Space weather modeling framework: a new tool for the space science community. Journal of Geophysical Research 110, A12226, doi:10.1029/2005JA011126]. We found that the position of the measured FAC is close to the positions predicted by the models, but the measured density can be greater than the model FAC densities. We discuss the possible reasons for the observed discrepancy between the measured and modeled FACs.
Publications - IC 17 | Alaska Division of Geological & Geophysical Surveys
DGGS IC 17 Publication Details Title: Coal resources of Alaska Authors: Alaska Division of Geological Statewide Bibliographic Reference Alaska Division of Geological & Geophysical Surveys, 1983, Coal Alaska Statewide Maps; Coal; Healy; Resource Assessment; Usibelli Mine Top of Page Department of Natural
The decommissioned Wurtsmith Air Force Base former Fire Training Cell (FT-02) facility has been the focus of several geophysical investigations. After several decades of fire training exercises, significant amounts of hydrocarbons and some solvents seeped into the subsurface cont...
The decommissioned Wurtsmith Air Force Base former Fire Training Cell (FT-02) facility has been the focus of several geophysical investigations. After several decades of fire training exercises, significant amounts of hydrocarbons and some solvents seeped into the Subsurface cont...
30 CFR 582.5 - Disclosure of data and information to the public.
Code of Federal Regulations, 2012 CFR
2012-07-01
... public. 582.5 Section 582.5 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE... or more leases, to ensure proper Mining Plans for a common orebody, or to promote operational safety...), unitization agreement, or joint Mining Plan. (c) Geophysical data, processed geophysical information, and...
30 CFR 582.5 - Disclosure of data and information to the public.
Code of Federal Regulations, 2013 CFR
2013-07-01
... public. 582.5 Section 582.5 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE... or more leases, to ensure proper Mining Plans for a common orebody, or to promote operational safety...), unitization agreement, or joint Mining Plan. (c) Geophysical data, processed geophysical information, and...
30 CFR 582.5 - Disclosure of data and information to the public.
Code of Federal Regulations, 2014 CFR
2014-07-01
... public. 582.5 Section 582.5 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE... or more leases, to ensure proper Mining Plans for a common orebody, or to promote operational safety...), unitization agreement, or joint Mining Plan. (c) Geophysical data, processed geophysical information, and...
Publications - GMC 28 | Alaska Division of Geological & Geophysical Surveys
DGGS GMC 28 Publication Details Title: Geochemical analysis (total organic carbon, rock-eval pyrolysis Reference Brown and Ruth Laboratories, Inc., 1985, Geochemical analysis (total organic carbon, rock-eval Organic Carbon Top of Page Department of Natural Resources, Division of Geological & Geophysical
Publications - GMC 294 | Alaska Division of Geological & Geophysical
DGGS GMC 294 Publication Details Title: Total organic carbon and rock-eval pyrolysis data of cuttings publication sales page for more information. Bibliographic Reference DGSI, Inc., 2000, Total organic carbon Organic Carbon Top of Page Department of Natural Resources, Division of Geological & Geophysical
Alaska Division of Geological and Geophysical Surveys
Name Title Gabriel Wolken, Ph.D. Program Manager Katreen Wikstrom Jones M.Sc. Geologist Research flood forecasting) rely on a quantitative assessment of distributed snow thickness and stored water . 2015. End-of-winter snow depth variability on glaciers in Alaska. Journal of Geophysical Research
Analysis of Publications and Citations from a Geophysics Research Institute.
ERIC Educational Resources Information Center
Frohlich, Cliff; Resler, Lynn
2001-01-01
Performs an analysis of all 1128 publications produced by scientists during their employment at the University of Texas Institute for Geophysics, thus assessing research performance using as bibliometric indicators such statistics as publications per year, citations per paper, and cited half-lives. Evaluates five different methods for determining…
Staff - Abraham M. Emond | Alaska Division of Geological & Geophysical
, and management of airborne electromagnetic and magnetic data under the AGGMI and SCM programs airborne magnetic, electromagnetic, and radiometric data. Prior to joining DGGS I worked as a geophysicist , Gina, and Goldak Airborne Surveys, 2015, Airborne magnetic geophysical survey of the Tanacross region
Publications - MP 126 | Alaska Division of Geological & Geophysical Surveys
DGGS MP 126 Publication Details Title: 400 MHz ground-penetrating radar, Itkillik River, North Slope , Itkillik River, North Slope, Alaska: Alaska Division of Geological & Geophysical Surveys Miscellaneous , North Slope, Alaska, scale 1:100 (8.6 M) Keywords Fluvial; Ground-Penetrating Radar; Itkillik River
Publications - SR 67 | Alaska Division of Geological & Geophysical Surveys
DGGS SR 67 Publication Details Title: Alaska's mineral industry 2011 - exploration activity Authors the mineral industry. Please take time to fill out the current mining and mineral activity - exploration activity: Alaska Division of Geological & Geophysical Surveys Special Report 67, 10 p. http
77 FR 19321 - Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf (OCS)
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-30
... by BOEM: (1) Oil and gas exploration and development; (2) renewable energy; and (3) marine minerals... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf (OCS) AGENCY: Bureau of Ocean Energy Management (BOEM...
Publications - MP 8 | Alaska Division of Geological & Geophysical Surveys
MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates STATEMAP Program information Geologic DGGS MP 8 Publication Details Title: Geothermal resources of Alaska Authors: Motyka, R.J., Moorman, M.A , S.A., 1983, Geothermal resources of Alaska: Alaska Division of Geological & Geophysical Surveys
25 CFR 211.56 - Geological and geophysical permits.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 211.56 Section 211.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS... contract, or authorize the production of, or removal of oil and gas, geothermal resources, or other...
25 CFR 211.56 - Geological and geophysical permits.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 25 Indians 1 2011-04-01 2011-04-01 false Geological and geophysical permits. 211.56 Section 211.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS... contract, or authorize the production of, or removal of oil and gas, geothermal resources, or other...
Publications - GMC 119 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a (Corona) well Authors: Unknown Publication Date: 1989 Publisher: Alaska Division of Geological & from OCS Y-0871-1 (Corona) well: Alaska Division of Geological & Geophysical Surveys Geologic
Publications - GMC 17 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a vitrinite reflectance) from Exxon Pt. Thompson #3 well Authors: AMOCO Publication Date: 1983 Publisher #3 well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center Data
Publications - GMC 106 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a microfossils from cuttings of Hemi Springs State #1 well Authors: Unknown Publication Date: 1989 Publisher Springs State #1 well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center
Publications - GMC 104 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a microfossils from cuttings of Kavearak Point 32-25 well Authors: Unknown Publication Date: 1988 Publisher Point 32-25 well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center Data
Publications - GMC 261 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ') of the ARCO Alaska Inc. Jones Island #1 well Authors: Unknown Publication Date: 1996 Publisher well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center Data Report 261
Publications - GMC 105 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a microfossils from cuttings of Gwydyr Bay State #2 well Authors: Unknown Publication Date: 1989 Publisher Bay State #2 well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center
25 CFR 211.56 - Geological and geophysical permits.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 25 Indians 1 2012-04-01 2011-04-01 true Geological and geophysical permits. 211.56 Section 211.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF TRIBAL LANDS... minerals, except samples for assay and experimental purposes, unless specifically so stated in the permit...
25 CFR 212.56 - Geological and geophysical permits.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 25 Indians 1 2012-04-01 2011-04-01 true Geological and geophysical permits. 212.56 Section 212.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS... samples for assay and experimental purposes, unless specifically so stated in the permit; and (3) Copies...
Alaska Division of Geological and Geophysical Surveys
; Divison of Geological & Geophysical Surveys> Engineering Geology Coastal Hazards Alaska's extensive shorelines are incompletely mapped and under-instrumented for the evaluation of coastal dynamics. The Coastal communities Updates to the Alaska Coastal Profile Tool including data in Norton Sound and St. Lawrence Island
Publications - GMC 381 | Alaska Division of Geological & Geophysical
DGGS GMC 381 Publication Details Title: 1974 summary report of exploration activities, Orange Hill information. Quadrangle(s): Nabesna Bibliographic Reference Trautwein, C.M., 2010, 1974 summary report of exploration activities, Orange Hill, Alaska: Alaska Division of Geological & Geophysical Surveys Geologic
Goddard Geophysical and Astronomical Observatory
NASA Technical Reports Server (NTRS)
Redmond, Jay; Kodak, Charles
2001-01-01
This report summarizes the technical parameters and the technical staff of the Very Long Base Interferometry (VLBI) system at the fundamental station Goddard Geophysical and Astronomical Observatory (GGAO). It also gives an overview about the VLBI activities during the previous year. The outlook lists the outstanding tasks to improve the performance of GGAO.
Geophysical Monitoring of Two types of Subsurface Injection
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...
Publications - AR 2010-C | Alaska Division of Geological & Geophysical
Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska content DGGS AR 2010-C Publication Details Title: Engineering Geology FY11 project descriptions Authors , Engineering Geology FY11 project descriptions, in DGGS Staff, Alaska Division of Geological & Geophysical
NASA Technical Reports Server (NTRS)
Cronin, A. G.; Delaney, J. R.
1973-01-01
The system is discussed which was developed to process digitized telemetry data from the intensity monitoring spectrometer flown on the Orbiting Geophysical Observatory (OGO-F) Satellite. Functional descriptions and operating instructions are included for each program in the system.
Publications - RI 2001-1A | Alaska Division of Geological & Geophysical
content DGGS RI 2001-1A Publication Details Title: Bedrock geologic map of the Chulitna region the Chulitna region, southcentral Alaska: Alaska Division of Geological & Geophysical Surveys ; Other Oversized Sheets Sheet 1 Bedrock geologic map of the Chulitna region, southcentral Alaska, scale 1
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-27
... DEPARTMENT OF THE INTERIOR U.S. Geological Survey [USGS-GX12GL00DT70500] Agency Information Collection Activities: National Geological and Geophysical Data Preservation Program (NGGDPP) AGENCY: U.S. Geological Survey (USGS), Interior. ACTION: Notice of an extension of an existing information collection...
Publications - AR 2014 | Alaska Division of Geological & Geophysical
Surveys Home About Us Director's Office Alaska Statutes Annual Reports Employment Staff Directory and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ; Geophysical Surveys Annual Report 2014 Authors: DGGS Staff Publication Date: Jan 2015 Publisher: Alaska
Geologic Communications | Alaska Division of Geological & Geophysical
improves a database for the Division's digital and map-based geological, geophysical, and geochemical data interfaces DGGS metadata and digital data distribution - Geospatial datasets published by DGGS are designed to be compatible with a broad variety of digital mapping software, to present DGGS's geospatial data
Staff - Susan S. Seitz | Alaska Division of Geological & Geophysical
, 2017, Geologic Photos of Alaska: Alaska Division of Geological & Geophysical Surveys Digital Data ., Seitz, S.S., and Mulliken, K.M., 2016, Digital compilation of geochemical data for historical samples (presentation): Digital Mapping Techniques Workshop, Champaign, Illinois, May 20-23, 2012: Alaska Division of
NASA Astrophysics Data System (ADS)
Zhang, Junwei
I built parts-based and manifold based mathematical learning model for the geophysical inverse problem and I applied this approach to two problems. One is related to the detection of the oil-water encroachment front during the water flooding of an oil reservoir. In this application, I propose a new 4D inversion approach based on the Gauss-Newton approach to invert time-lapse cross-well resistance data. The goal of this study is to image the position of the oil-water encroachment front in a heterogeneous clayey sand reservoir. This approach is based on explicitly connecting the change of resistivity to the petrophysical properties controlling the position of the front (porosity and permeability) and to the saturation of the water phase through a petrophysical resistivity model accounting for bulk and surface conductivity contributions and saturation. The distributions of the permeability and porosity are also inverted using the time-lapse resistivity data in order to better reconstruct the position of the oil water encroachment front. In our synthetic test case, we get a better position of the front with the by-products of porosity and permeability inferences near the flow trajectory and close to the wells. The numerical simulations show that the position of the front is recovered well but the distribution of the recovered porosity and permeability is only fair. A comparison with a commercial code based on a classical Gauss-Newton approach with no information provided by the two-phase flow model fails to recover the position of the front. The new approach could be also used for the time-lapse monitoring of various processes in both geothermal fields and oil and gas reservoirs using a combination of geophysical methods. A paper has been published in Geophysical Journal International on this topic and I am the first author of this paper. The second application is related to the detection of geological facies boundaries and their deforation to satisfy to geophysica data and prior distributions. We pose the geophysical inverse problem in terms of Gaussian random fields with mean functions controlled by petrophysical relationships and covariance functions controlled by a prior geological cross-section, including the definition of spatial boundaries for the geological facies. The petrophysical relationship problem is formulated as a regression problem upon each facies. The inversion is performed in a Bayesian framework. We demonstrate the usefulness of this strategy using a first synthetic case study, performing a joint inversion of gravity and galvanometric resistivity data with the stations all located at the ground surface. The joint inversion is used to recover the density and resistivity distributions of the subsurface. In a second step, we consider the possibility that the facies boundaries are deformable and their shapes are inverted as well. We use the level set approach to deform the facies boundaries preserving prior topological properties of the facies throughout the inversion. With the additional help of prior facies petrophysical relationships, topological characteristic of each facies, we make posterior inference about multiple geophysical tomograms based on their corresponding geophysical data misfits. The result of the inversion technique is encouraging when applied to a second synthetic case study, showing that we can recover the heterogeneities inside the facies, the mean values for the petrophysical properties, and, to some extent, the facies boundaries. A paper has been submitted to Geophysics on this topic and I am the first author of this paper. During this thesis, I also worked on the time lapse inversion problem of gravity data in collaboration with Marios Karaoulis and a paper was published in Geophysical Journal international on this topic. I also worked on the time-lapse inversion of cross-well geophysical data (seismic and resistivity) using both a structural approach named the cross-gradient approach and a petrophysical approach. A paper was published in Geophysics on this topic.
Geophysical Data from Offshore of the Chandeleur Islands, Eastern Mississippi Delta
Baldwin, Wayne E.; Pendleton, Elizabeth A.; Twichell, David C.
2009-01-01
This report contains the geophysical and geospatial data that were collected during two cruises on the R/V Acadiana along the eastern, offshore side of the Chandeleur Islands in 2006 and 2007. Data were acquired with the following equipment: a Systems Engineering and Assessment, Ltd., SwathPlus interferometric sonar; a Klein 3000 dual-frequency sidescan sonar; and an EdgeTech 512i chirp sub-bottom profiling system. The long-term goal of this mapping effort is to produce high-quality, high-resolution geologic maps and geophysical interpretations that can be utilized to investigate the impact of Hurricane Katrina, identify sand resources within the region, and make predictions regarding the future evolution of this coastal system.
Introduction to violent Sun-Earth connection events of October-November 2003
NASA Astrophysics Data System (ADS)
Gopalswamy, N.; Barbieri, L.; Cliver, E. W.; Lu, G.; Plunkett, S. P.; Skoug, R. M.
2005-09-01
The solar-terrestrial events of late October and early November 2003, popularly referred to as the Halloween storms, represent the best observed cases of extreme space weather activity observed to date and have generated research covering multiple aspects of solar eruptions and their space weather effects. In the following article, which serves as an abstract for this collective research, we present highlights taken from 61 of the 74 papers from the Journal of Geophysical Research, Geophysical Research Letters, and Space Weather which are linked under this special issue. (An overview of the 13 associated papers published in Geophysics Research Letters is given in the work of Gopalswamy et al. (2005a)).
Women and Science in El Salvador
NASA Astrophysics Data System (ADS)
de Maria Mendez Martınez, Luz; Portillo, Mercy; Elías, José Héctor
2009-04-01
Physics is rarely pursued by El Salvadoran students. As in most Latin-American countries, there exists the false idea in El Salvador that some careers should be exclusively for men, such as engineering and hard sciences like physics. Because El Salvador is a natural laboratory for geophysical phenomena, due to the existence of more than 20 volcanoes, prevalent seismic activity, and large production of geothermic energy, geophysics is the most common branch of physics studied in El Salvador. The numbers and gender breakdown of physics and geophysics students at the University of El Salvador in the years since the last IUPAP Women in Physics Conference in 2005 are presented, and the numbers are encouraging.
Stewart, John Harris; Chaffee, M.A.; Dohrenwend, J.C.; John, D.A.; Kistler, R.W.; Kleinhampl, F.J.; Menzie, W.D.; Plouff, Donald; Rowan, L.C.; Silberling, Norman J.
1984-01-01
The Walker Lake 1? by 2? quadrangle in eastern California and western Nevada was studied by an interdisciplinary research team to appraise its mineral resources. The appraisal is based on geological, geochemical, and geophysical field and laboratory investigations, the results of which are published as a folio of maps, figures, and tables, with accompanying discussions. This circular provides background information on the investigations and integrates the information presented in the folio. The selected bibliography lists selected references to the geology, geochemistry, geophysics, and mineral deposits of the Walker Lake 1? by 2? quadrangle.
Solid earth geophysics: Data services
NASA Astrophysics Data System (ADS)
1987-01-01
The National Oceanic and Atmospheric Administration (NOAA) collects, manages, and disseminates many kinds of scientific data that result from the inquiry into the environment. The National Geophysical Data Center (NGDC), one of the several data-management centers of NOAA, is responsible for data activities in the fields of seismology, gravity, topography, geomagnetism, geothermics, marine geology and geophysics, and solar-terrestrial physics. The pamphlet briefly describes the principal products and services NGDC provides through its Solid Earth (SEG) division. Among the most important activities of SEG are acquiring and archiving data, processing and formatting data into standard sets, developing useful data products for customers, and advertising and disseminating data to the scientific, academic, and industrial communities.
Publications of the Volcano Hazards Program 2005
Nathenson, Manuel
2007-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Envision: An interactive system for the management and visualization of large geophysical data sets
NASA Technical Reports Server (NTRS)
Searight, K. R.; Wojtowicz, D. P.; Walsh, J. E.; Pathi, S.; Bowman, K. P.; Wilhelmson, R. B.
1995-01-01
Envision is a software project at the University of Illinois and Texas A&M, funded by NASA's Applied Information Systems Research Project. It provides researchers in the geophysical sciences convenient ways to manage, browse, and visualize large observed or model data sets. Envision integrates data management, analysis, and visualization of geophysical data in an interactive environment. It employs commonly used standards in data formats, operating systems, networking, and graphics. It also attempts, wherever possible, to integrate with existing scientific visualization and analysis software. Envision has an easy-to-use graphical interface, distributed process components, and an extensible design. It is a public domain package, freely available to the scientific community.
Smith, James G.; Blakely, R.J.; Johnson, M.G.; Page, N.J.; Peterson, J.A.; Singer, D.A.; Whittington, C.L.
1986-01-01
The Medford 1 ? by 2 ? quadrangle in southern Oregon and northern California was studied by an interdisciplinary research team to appraise its mineral resources. The appraisal is based on geological, geochemical, and geophysical field and laboratory investigations, the results of which are published as a folio of maps, figures, and tables, with accompanying discussions. This circular provides background information on the investigations and integrates the information presented in the folio. The bibliography lists selected references to the geology, geochemistry, geophysics, and mineral deposits of the Medford 1 ? by 2 ? quadrangle.
Publications of the Volcano Hazards Program 2002
Nathenson, Manuel
2004-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Publications of the Volcano Hazards Program 2006
Nathenson, Manuel
2008-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Publications of the Volcano Hazards Program 2007
Nathenson, Manuel
2009-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Publications of the Volcano Hazards Program 2004
Nathenson, Manuel
2006-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This bibliographic report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Publications of the Volcano Hazards Program 2001
Nathenson, Manuel
2002-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Publications of the Volcano Hazards Program 2008
Nathenson, Manuel
2010-01-01
The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Manoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.
Reports of planetary geology and geophysics program, 1988
NASA Technical Reports Server (NTRS)
Holt, Henry E. (Editor)
1989-01-01
This is a compilation of abstracts of reports from Principal Investigators of NASA's Planetary Geology and Geophysics Program, Office of Space Science and Applications. The purpose is to document in summary form research work conducted in this program during 1988. Each report reflects significant accomplishments within the area of the author's funded grant or contract.
30 CFR 250.175 - When may the Regional Supervisor grant an SOO?
Code of Federal Regulations, 2010 CFR
2010-07-01
... processing or interpretation of the geophysical information with the objective of identifying a potential... processing or interpretation of existing geophysical data or information; (ii) acquire, process, or interpret... mean sea level (TVD SS) when all of the following conditions are met: (1) The lease was issued with a...
30 CFR 280.51 - What types of geophysical data and information must I submit to MMS?
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What types of geophysical data and information must I submit to MMS? 280.51 Section 280.51 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... magnetic surveys, and special studies such as refraction and velocity surveys. ...
Directory of research projects, 1991. Planetary geology and geophysics program
NASA Technical Reports Server (NTRS)
Maxwell, Ted A. (Editor)
1991-01-01
Information is provided about currently funded scientific research within the Planetary Geology and Geophysics Program. The directory consists of the proposal summary sheet from each proposal funded by the program during fiscal year 1991. Information is provided on the research topic, principal investigator, institution, summary of research objectives, past accomplishments, and proposed investigators.
Staff - Gabriel J. Wolken | Alaska Division of Geological & Geophysical
Facebook DGGS News Natural Resources Geological & Geophysical Surveys Staff - Gabriel J. Wolken main content Gabriel J. Wolken Gabriel J. Wolken Glaciology, climatology, geomorphology, snow science, geologic ., 2014, Arctic glaciers and ice caps (outside Greenland), in Blunden, J. and Arndt, D.S., eds., State of
Introduction of Special Physics Topics (Geophysics) Through the Use of Physics Laboratory Projects
ERIC Educational Resources Information Center
Parker, R. H.; Whittles, A. B. L.
1970-01-01
Describes the objectives and content of a physics laboratory program for freshman students at the British Columbia Institute of Technology. The first part of the program consists of basic physics experiments, while the second part emphasizes student work on projects in geophysics that have direct technical applications. (LC)
Hands-On Teaching through a Student Field Project in Applied Geophysics.
ERIC Educational Resources Information Center
Klasner, John Samuel; Crockett, Jeffrey Jon; Horton, Kimberly Beth; Poe, Michele Daun; Wollert, Matthew Todd
1992-01-01
Describes the Proffit Mountain project, part of a senior-level class in applied geophysics that provides students with hands-on experience in applying principles and techniques learned in class. Students conduct magnetic, gravity, and radiometric studies over a diabase body which intrudes rhyolite at Proffitt Mountain in southeast Missouri.…
Dissolved oxygen, dissolved nitrous oxide, and water temperature in reservoirs.This dataset is associated with the following publication:Beaulieu , J., C. Nietch , and J. Young. Source or sink: Insight on controls of nitrous oxide biogeochemistry from a 20 reservoir survey. Journal of Geophysical Research - Biogeosciences. American Geophysical Union, Washington, DC, USA, 120(10): 1995-2010, (2015).
Publications - GMC 235 | Alaska Division of Geological & Geophysical
reflectance data from cuttings (1,890-11,060') of the Texaco Inc. West Kurupa Unit #1 well Authors: Bird, Ken , and Pawlewicz, Mark Publication Date: 1994 Publisher: Alaska Division of Geological & Geophysical information. Bibliographic Reference Bird, Ken, and Pawlewicz, Mark, 1994, Rock-eval data from cuttings (580
NASA Technical Reports Server (NTRS)
1972-01-01
Satellite tracking and earth dynamics research programs are discussed. Geodetic and geophysical investigations are reported along with atmospheric research using satellite drag data. Satellite tracking network functions and support groups which are discussed include: network operations, communications, data-services division, moonwatch, and programming group.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dudley, Colton; Dorsey, Alison; Louie, John
Colton Dudley, Alison Dorsey, Paul Opdyke, Dustin Naphan, Marlon Ramos, John Louie, Paul Schwering, and Satish Pullammanappallil, 2013, Near-surface geophysical characterization of Holocene faults conducive to geothermal flow near Pyramid Lake, Nevada: presented at Amer. Assoc. Petroleum Geologists, Pacific Section Annual Meeting, Monterey, Calif., April 19-25.
25 CFR 212.56 - Geological and geophysical permits.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 212.56 Section 212.56 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS..., authorize the production of, or removal of oil and gas, or geothermal resources, or other minerals except...
NASA Astrophysics Data System (ADS)
iMOST Team; Herd, C. D. K.; Ammannito, E.; Anand, M.; Debaille, V.; Hallis, L. J.; McCubbin, F. M.; Schmitz, N.; Usui, T.; Weiss, B. P.; Altieri, F.; Amelin, Y.; Beaty, D. W.; Benning, L. G.; Bishop, J. L.; Borg, L. E.; Boucher, D.; Brucato, J. R.; Busemann, H.; Campbell, K. A.; Carrier, B. L.; Czaja, A. D.; Des Marais, D. J.; Dixon, M.; Ehlmann, B. L.; Farmer, J. D.; Fernandez-Remolar, D. C.; Fogarty, J.; Glavin, D. P.; Goreva, Y. S.; Grady, M. M.; Harrington, A. D.; Hausrath, E. M.; Horgan, B.; Humayun, M.; Kleine, T.; Kleinhenz, J.; Mangold, N.; Mackelprang, R.; Mayhew, L. E.; McCoy, J. T.; McLennan, S. M.; McSween, H. Y.; Moser, D. E.; Moynier, F.; Mustard, J. F.; Niles, P. B.; Ori, G. G.; Raulin, F.; Rettberg, P.; Rucker, M. A.; Sefton-Nash, E.; Sephton, M. A.; Shaheen, R.; Shuster, D. L.; Siljestrom, S.; Smith, C. L.; Spry, J. A.; Steele, A.; Swindle, T. D.; ten Kate, I. L.; Tosca, N. J.; Van Kranendonk, M. J.; Wadhwa, M.; Werner, S. C.; Westall, F.; Wheeler, R. M.; Zipfel, J.; Zorzano, M. P.
2018-04-01
We present the main sample types from any potential Mars Sample Return landing site that would be required to constrain the geological and geophysical processes on Mars, including the origin and nature of its crust, mantle, and core.
Publications - GMC 79 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a Island #A-3) well Authors: Unknown Publication Date: 1988 Publisher: Alaska Division of Geological & Western BF-57 #1 (Seal Island #A-3) well: Alaska Division of Geological & Geophysical Surveys Geologic
Publications - GMC 96 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a Corp.) North cook Inlet Unit A-12 (A-15) well Authors: Core Laboratories Publication Date: 1988 Unit A-12 (A-15) well: Alaska Division of Geological & Geophysical Surveys Geologic Materials
Publications - GMC 48 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a DGGS GMC 48 Publication Details Title: Palynology of the Susie Unit #1 well, North Slope, Alaska , Palynology of the Susie Unit #1 well, North Slope, Alaska: Alaska Division of Geological & Geophysical
Publications - GMC 216 | Alaska Division of Geological & Geophysical
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a report of the U.S. Navy Fish Creek # 1 well Authors: Core Laboratories Publication Date: 1993 Publisher Fish Creek # 1 well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center
Publications - GMC 78 | Alaska Division of Geological & Geophysical Surveys
and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a DGGS GMC 78 Publication Details Title: Vitrinite reflectance data for OCS-Y-0344-1 (Mukluk #1) well ) well: Alaska Division of Geological & Geophysical Surveys Geologic Materials Center Data Report 78
Staff - Ronald P. Daanen | Alaska Division of Geological & Geophysical
conditions at an arable field soil with snow cover near Sjökulla, Finland) 1994 - B.A., Environmental , Terrestrial Lidar Observations of Frost Heave and Soil Motion 2009-2011, Research Associate, Geophysical effects of Groundwater Manipulation, Terrestrial Lidar Observations of Frost Heave and Soil Motion 2005
Reports of Planetary Geology and Geophysics Program, 1986
NASA Technical Reports Server (NTRS)
1987-01-01
Abstracts compiled from reports from Principal Investigators of the NASA Planetary Geology and Geophysics Program, Office of Space Science and Applications are presented. The purpose is to document in summary form work conducted in this program during 1986. Each report reflects significant accomplishments within the area of the author's funded grant or contract.
Publications - RDF 2015-7 | Alaska Division of Geological & Geophysical
, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical
Publications - RDF 2015-5 | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska
Publications - RI 2009-2 | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska
Publications - MP 142 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - RDF 2016-3 | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska
Publications - SR 70 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - MP 38 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - RDF 2005-4 | Alaska Division of Geological & Geophysical
District; Trace Elements; Trace Metals; Tungsten; Uranium; Vanadium; Yttrium; Zinc; Zirconium Top of Page Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical
Publications - SR 45 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - RDF 2016-5 | Alaska Division of Geological & Geophysical
Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska
Publications - MP 43 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum