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Sample records for earth movements geophysics

  1. GEOPHYSICS: Atmosphere Drives Earth's Tipsiness.

    PubMed

    Kerr, R A

    2000-08-04

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

  2. Earth Rotational Variations Excited by Geophysical Fluids

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

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

  3. Geophysical Effects of the Earth's Monthly Motion

    NASA Astrophysics Data System (ADS)

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

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

  4. Solid-Earth Geophysics in Latinamerica

    NASA Astrophysics Data System (ADS)

    Urrutia-F, J.

    2003-12-01

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

  5. 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

  6. 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.

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

    NASA Technical Reports Server (NTRS)

    Lambeck, K.

    1978-01-01

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

  8. 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.

  9. The earth's forced nutations - Geophysical implications

    NASA Technical Reports Server (NTRS)

    Wahr, J. M.; De Vries, D.

    1990-01-01

    Theories of nutation are examined critically to develop an extension of the theoretical description based on an earth in nonhydrostatic equilibrium. The estimation of nutation amplitude as a function of frequency is reviewed with reference to contributing variables such as the oceans, mantle anelasticity, and nonhydrostatic structure. Theoretical results by Wahr (1981) are compared to those of VLBI observations, and other VLBI data are used to discuss Wahr and Bergen's (1986) theoretical nutation admittances for an anelastic earth. The contributions associated with the tilt-over mode and with free-core nutations (FCN) are discussed, and the contribution of anelasticity is examined. The VLBI data show that nutation data are important sources of information regarding the earth's interior. Nutation amplitudes are derived with a model for a nonhydrostatically prestressed earth to determine the FCN contributions.

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

    DOEpatents

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

    2008-05-20

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

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

    SciTech Connect

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

    2009-05-15

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

  12. Studies in geophysics: The Earth's electrical environment

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The Earth is electrified. Between the surface and the outer reaches of the atmosphere, there is a global circuit that is maintained by worldwide thunderstorm activity and by upper atmospheric dynamo processes. The highest voltages approach a billion volts and are generated within thunderclouds, where lightning is a visual display of the cloud's electrical nature. The largest currents in the circuit, approaching a million amperes, are associated with the aurora. Because there have been significant advances in understanding many of the component parts of the global electric circuit (lightning, cloud electrification, electrical processes in specific atmospheric regions, and telluric currents), a principal research challenge is to understand how these components interact to shape the global circuit. Increased basic understanding in this field has many potential practical applications, including lightning protection, the design of advanced aircraft and spacecraft, and improvements in weather prediction.

  13. The Environmental Movement: Beyond Earth Day.

    ERIC Educational Resources Information Center

    Baker, Beth

    1995-01-01

    This collection of articles looks at the history of Earth Day and the future of the environmental movement and environmental organizations. Examines reasons environmental organizations are losing support while the public remains committed to the environment. (LZ)

  14. The solid earth: An introduction to global geophysics

    SciTech Connect

    Fowler, C.M.R.

    1990-01-01

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

  15. The Earth surface slide movement at Soledad

    NASA Astrophysics Data System (ADS)

    Moreno, A.

    1986-11-01

    The Earth surface slide movement at Soledad is a mountain-slide type of movement. Estimations of the thickness of the layer which is moving range between 10 and 100 m. There is no proof that the movement is water induced, but it could be influenced by the water household. The slope of the slide area is H: D = 1: 2. The height difference in the moving area studied, according to this paper, is 1 km. The actual rate of movement is about 12 cm/yr.

  16. 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…

  17. Geophysical Techniques for Monitoring CO2 Movement During Sequestration

    SciTech Connect

    Erika Gasperikova; G. Michael Hoversten

    2005-11-15

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

  18. Geophysical, petrological and mineral physics constraints on Earth's surface topography

    NASA Astrophysics Data System (ADS)

    Guerri, Mattia; Cammarano, Fabio; Tackley, Paul J.

    2015-04-01

    Earth's surface topography is controlled by isostatically compensated density variations within the lithosphere, but dynamic topography - i.e. the topography due to adjustment of surface to mantle convection - is an important component, specially at a global scale. In order to separate these two components it is fundamental to estimate crustal and mantle density structure and rheological properties. Usually, crustal density is constrained from interpretation of available seismic data (mostly VP profiles) based on empirical relationships such those in Brocher [2005]. Mantle density structure is inferred from seismic tomography models. Constant coefficients are used to interpret seismic velocity anomalies in density anomalies. These simplified methods are unable to model the effects that pressure and temperature variations have on mineralogical assemblage and physical properties. Our approach is based on a multidisciplinary method that involves geophysical observables, mineral physics constraints, and petrological data. Mantle density is based on the thermal interpretation of global seismic tomography models assuming various compositional structures, as in Cammarano et al. [2011]. We further constrain the top 150 km by including heat-flow data and considering the thermal evolution of the oceanic lithosphere. Crustal density is calculated as in Guerri and Cammarano [2015] performing thermodynamic modeling of various average chemical compositions proposed for the crust. The modeling, performed with the code PerpleX [Connolly, 2005], relies on the thermodynamic dataset from Holland and Powell [1998]. Compressional waves velocity and crustal layers thickness from the model CRUST 1.0 [Laske et al., 2013] offer additional constrains. The resulting lithospheric density models are tested against gravity (GOCE) data. Various crustal and mantle density models have been tested in order to ascertain the effects that uncertainties in the estimate of those features have on the

  19. Applied geophysical techniques to evaluate earth dams and foundations

    NASA Astrophysics Data System (ADS)

    Llopis, Jose L.; Sharp, Michael K.; Butler, Dwain K.; Yule, Donald E.

    1995-05-01

    Mill Creek Dam, near Walla Walla, Washington has experienced anomalous seepage since its first filling in 1941. Various attempts to abate and control the seepage, including construction of a concrete wall, have not been completely successful. Construction of the cutoff wall reduced the seepage by about 30 percent, from 33 cubic feet per second to 22 cubic feet per second, and downstream saturated farmland was reduced by 56 percent. However, there are indications of increased seepage pressures in a conglomerate formation in the right abutment. A comprehensive, integrated geophysics investigation of the right abutment area of the dam was conducted to detect and map anomalous conditions and assist in the evaluation of remedial measures. The geophysics program consisted of microgravity, ground penetrating radar, seismic reflection, electromagnetic conductivity, and electrical resistivity surveying. Results of the program indicate anomalous conditions extending from the reservoir area through the right abutment. The aspects of the program planning leading to technique selection and field procedures are emphasized, as well as the role of different geophysical techniques in defining the nature of anomalous condition.

  20. Geophysical tomography for imaging water movement in welded tuff

    SciTech Connect

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

    1986-09-01

    Alterant tomography has been evaluated for its ability to delineate in-situ water flow paths in a fractured welded-tuff rock mass. The evaluation involved a field experiment in which tomographs of electromagnetic attenuation factor (or attenuation rate) at 300 MHz were made before, during, and after the introduction to the rock of two different water-based tracers: a plain water and dye solution, and salt water and dye. Alterant tomographs were constructed by subtracting, cell by cell, the attenuation factors derived from measurements before each tracer was added to the rock mass from the attenuation factors derived after each tracer was added. The alterant tomographs were compared with other evidence of water movement in the rock: borescope logs of fractures, and post experiment cores used to locate the dye tracer on the fractured surfaces. These comparisons indicate that alterant tomography is suitable for mapping water flow through fractures and that it may be useful in inferring which of the fractures are hydrologically connected in the image plane. The technique appears to be sensitive enough to delineate flow through a single fracture and to define fractures with a spatial resolution of about 10 cm on an imaging scale of a few meters. 9 refs., 3 figs.

  1. 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.

  2. Refining 3D Earth models by unifying geological and geophysical information on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Lelièvre, P. G.; Carter-McAuslan, A.; Tycholiz, C.; Farquharson, C. G.; Hurich, C. A.

    2012-04-01

    Earth models used for mineral exploration or other subsurface investigations should be consistent with all available geological and geophysical information. Geophysical inversion provides the means to integrate geological information, geophysical survey data, and physical property measurements taken on rock samples. Incorporation of geological information into inversions is always an iterative process. One begins with the geologists' best guess about the Earth (i.e. the geological model) and the models recovered from geophysical inversion may indicate that the geological model should be changed slightly prior to the next iteration of the procedure. In this way, geological and geophysical data can be combined through inversion and we can move towards the creation of a common Earth model consistent with all the available data. As more information is incorporated, the inherent non-uniqueness of the inverse problem is reduced, yielding a higher potential to resolve deeper features that are less well-constrained by the geophysical data alone. Geological ore deposit models are commonly created during delineation drilling. The accuracy of these models is crucial when used to determine if a deposit is economic. 3D geological Earth models typically comprise wireframe surfaces that represent the geological contacts between different rock units. The contacts may be known at points from down-hole intersections and surface mapping, and can be interpolated between boreholes and extrapolated outwards. Contacts may also be interpreted from seismic traces. Wireframe surfaces, comprising tessellated triangular facets, are sufficiently flexible to allow the representation of arbitrarily complicated geological structures. These surfaces can be honoured exactly within fully unstructured 3D volumetric tetrahedral meshes. In contrast, geophysical forward modelling and inversion algorithms typically work with rectilinear meshes when parameterizing the subsurface because this simplifies

  3. At quadrennial geophysics fest, earth scientists think globally

    SciTech Connect

    Kerr, R.A.

    1995-07-28

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

  4. Geophysics

    NASA Technical Reports Server (NTRS)

    Carr, M. H.; Cassen, P.

    1976-01-01

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

  5. Investigation of novel geophysical techniques for monitoring CO2 movement during sequestration

    SciTech Connect

    Hoversten, G. Michael; Gasperikova, Erika

    2003-10-31

    Cost effective monitoring of reservoir fluid movement during CO{sub 2} sequestration is a necessary part of a practical geologic sequestration strategy. Current petroleum industry seismic techniques are well developed for monitoring production in petroleum reservoirs. The cost of time-lapse seismic monitoring can be born because the cost to benefit ratio is small in the production of profit making hydrocarbon. However, the cost of seismic monitoring techniques is more difficult to justify in an environment of sequestration where the process produces no direct profit. For this reasons other geophysical techniques, which might provide sufficient monitoring resolution at a significantly lower cost, need to be considered. In order to evaluate alternative geophysical monitoring techniques we have undertaken a series of numerical simulations of CO{sub 2} sequestration scenarios. These scenarios have included existing projects (Sleipner in the North Sea), future planned projects (GeoSeq Liberty test in South Texas and Schrader Bluff in Alaska) as well as hypothetical models based on generic geologic settings potentially attractive for CO{sub 2} sequestration. In addition, we have done considerable work on geophysical monitoring of CO{sub 2} injection into existing oil and gas fields, including a model study of the Weyburn CO{sub 2} project in Canada and the Chevron Lost Hills CO{sub 2} pilot in Southern California (Hoversten et al. 2003). Although we are specifically interested in considering ''novel'' geophysical techniques for monitoring we have chosen to include more traditional seismic techniques as a bench mark so that any quantitative results derived for non-seismic techniques can be directly compared to the industry standard seismic results. This approach will put all of our finding for ''novel'' techniques in the context of the seismic method and allow a quantitative analysis of the cost/benefit ratios of the newly considered methods compared to the traditional

  6. Earth's mantle composition and thermal state - A geophysical perspective.

    NASA Astrophysics Data System (ADS)

    Khan, A.

    2011-12-01

    We jointly invert local fundamental-mode and higher-order surface-wave phase-velocities for radial models of the thermo-chemical and anisotropic physical structure of the Earth's mantle to ~1000 km depth beneath the North American continent. Inversion for thermo-chemical state relies on a self-consistent thermodynamic method whereby phase equilibria and physical properties (P-, S-wave velocity and density) are computed as functions of composition (in the Na2O-CaO-FeO-MgO-Al2O3-SiO2 model system), pressure and temperature. We employ a sampling-based strategy to solve the non-linear inverse problem from which a range of models fitting the observations within uncertainties are obtained. Our thermo-chemical maps reveal the tectonically stable older eastern parts of North America to be chemically depleted (high Mg#) and colder (>200 deg C) relative to the active younger regions (western margin and oceans). In the transition zone the thermo-chemical structure decouples from that of the upper mantle, with a relatively hot thermal anomaly appearing beneath the cratonic area that likely extends into the lower mantle. In the lower mantle no consistent large-scale thermo-chemical heterogeneities are observed, although our results do suggest distinct upper and lower mantle compositions.

  7. Expanding Earth and declining gravity: a chapter in the recent history of geophysics

    NASA Astrophysics Data System (ADS)

    Kragh, H.

    2015-05-01

    Although speculative ideas of an expanding Earth can be found before World War II, it was only in the 1950s and 1960s that the theory attracted serious attention among a minority of earth scientists. While some of the proponents of the expanding Earth adopted an empiricist attitude by disregarding the physical cause of the assumed expansion, others argued that the cause, either fully or in part, was of cosmological origin. They referred to the possibility that the gravitational constant was slowly decreasing in time, as first suggested by P. Dirac in 1937. As a result of a stronger gravitation in the past, the ancient Earth would have been smaller than today. The gravitational argument for an expanding Earth was proposed by P. Jordan and L. Egyed in the 1950s and during the next 2 decades it was discussed by several physicists, astronomers and earth scientists. Among those who for a period felt attracted by "gravitational expansionism" were A. Holmes, J. Tuzo Wilson and F. Hoyle. The paper examines the idea of a varying gravitational constant and its impact on geophysics in the period from about 1955 to the mid-1970s.

  8. Melting and melt-movement in the Earth

    NASA Astrophysics Data System (ADS)

    White, Robert S.

    Researchers came together to discuss melting and melt-movement in the Earth at a 2-day Royal Society Discussion Meeting held in March 1992 at the Royal Society, London.In recent years, many new tools have become available to geologists studying igneous and metamorphic rocks. They can be examined at ever-higher magnifications: the composition within individual crystals can be measured; their isotopic, trace, and rare-earth element concentrations can be determined; and measurements of partition coefficients and melting behavior can be made in the laboratory at pressures and temperatures appropriate to in-situ rocks. Along with these improvements in instrumentation and experimental techniques, advances have been made in understanding the physics of melt generation and separation, and computers have been developed that are sufficiently powerful to model theoretical formulations of the behavior of melt in the Earth.

  9. 7 CFR 330.302 - Domestic movements of earth (including soil), stone, etc.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Domestic movements of earth (including soil), stone... Products § 330.302 Domestic movements of earth (including soil), stone, etc. The interstate movement from regulated areas in the Continental United States of earth (including soil), stone, quarry products,...

  10. 7 CFR 330.302 - Domestic movements of earth (including soil), stone, etc.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Domestic movements of earth (including soil), stone... Products § 330.302 Domestic movements of earth (including soil), stone, etc. The interstate movement from regulated areas in the Continental United States of earth (including soil), stone, quarry products,...

  11. 7 CFR 330.302 - Domestic movements of earth (including soil), stone, etc.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Domestic movements of earth (including soil), stone... Products § 330.302 Domestic movements of earth (including soil), stone, etc. The interstate movement from regulated areas in the Continental United States of earth (including soil), stone, quarry products,...

  12. 7 CFR 330.302 - Domestic movements of earth (including soil), stone, etc.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Domestic movements of earth (including soil), stone... Products § 330.302 Domestic movements of earth (including soil), stone, etc. The interstate movement from regulated areas in the Continental United States of earth (including soil), stone, quarry products,...

  13. 7 CFR 330.302 - Domestic movements of earth (including soil), stone, etc.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Domestic movements of earth (including soil), stone... Products § 330.302 Domestic movements of earth (including soil), stone, etc. The interstate movement from regulated areas in the Continental United States of earth (including soil), stone, quarry products,...

  14. Halogen and phosphorus storage in the earth. [elemental spatial distribution from geochemical, geophysical, and cosmochemical factors

    NASA Technical Reports Server (NTRS)

    Smith, J. V.

    1981-01-01

    Chemical analyses of surface reservoirs, coupled with compositions for interior zones inferred from geophysical and geochemical data have been used to obtain a range of estimates of the bulk composition of the earth. It is suggested that (1) apatite with 3 wt% Fe, up to 1 wt% Cl, and 0.003 wt% Br is the principal mineral reservoir for halogens, and mica is a subsidiary reservoir; (2) apatite with 18 wt% P is the principal store of P in the upper mantle and perhaps lower mantle, but accounts for only one-twentieth of P in the earth; and (3) the remaining P is in a reservoir inaccessible to magmatism, and may amount to a maximum of 0.7 wt% in the core.

  15. Discover Our Earth: Web-Based Geophysical Data in the Classroom

    NASA Astrophysics Data System (ADS)

    Moore, A.; Seber, D.; Danowski, D.; Brindisi, C.

    2002-12-01

    Discover Our Earth is a web-based system designed for classroom use, allowing access and display of geospatial data sets . It is an education and outreach module built as part of Cornell University's Geoscience Information System, originally constructed as a tool for geophysical research (http://atlas.geo.cornell.edu). Discover Our Earth has been used in university, high school and middle school classrooms. Working with real data is a powerful tool for helping students learn scientific principles, content, and the processes of scientific inquiry. In order to give students access to data that is otherwise difficult to work with, Discover Our Earth is comprised of several elements. The central component is a Java applet called QUEST (Quick Use Earth Study Tool). QUEST allows students to query and display data from three data sets selected from the 100+ housed within the Information System. Any attribute of earthquake, volcano, or topographic data can be selected and displayed, and multiple data sets can be overlain on each other, or on assorted background images (such as a geographic base map, age of the sea floor etc). Each image is saved in the QUEST history window, allowing students to compare multiple selections, or to animate a series of images as a "filmstrip." In order to help students better understand their results, the QUEST applet is supported by several other components. There are guides for both teacher and student. The student guide gives step-by-step instructions for a series of problems, and suggests others that will help students answer questions of local and global interest. The teacher guide provides background material, context, and answers to the student exercises. There are animations and 3-D visualizations that allow students to better interpret their maps. Additionally, there are interactive experiments on topics such as continental drift, isostasy, viscosity, that allow students to explore the physics that underlie the processes they are

  16. Observation of the Earth's nutation by the VLBI: how accurate is the geophysical signal

    NASA Astrophysics Data System (ADS)

    Gattano, César; Lambert, Sébastien B.; Bizouard, Christian

    2016-09-01

    We compare nutation time series determined by several International VLBI Service for geodesy and astrometry (IVS) analysis centers. These series were made available through the International Earth Rotation and Reference Systems Service (IERS). We adjust the amplitudes of the main nutations, including the free motion associated with the free core nutation (FCN). Then, we discuss the results in terms of physics of the Earth's interior. We find consistent FCN signals in all of the time series, and we provide corrections to IAU 2000A series for a number of nutation terms with realistic errors. It appears that the analysis configuration or the software packages used by each analysis center introduce an error comparable to the amplitude of the prominent corrections. We show that the inconsistencies between series have significant consequences on our understanding of the Earth's deep interior, especially for the free inner core resonance: they induce an uncertainty on the FCN period of about 0.5 day, and on the free inner core nutation (FICN) period of more than 1000 days, comparable to the estimated period itself. Though the FCN parameters are not so much affected, a 100 % error shows up for the FICN parameters and prevents from geophysical conclusions.

  17. Satellite-tracking and earth-dynamics research programs. [geodetic and geophysical investigations and atmospheric research using satellite drag data

    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.

  18. Integrating Diverse Geophysical and Geological Data to Construct Multi-Dimensional Earth Models: The Open Earth Framework

    NASA Astrophysics Data System (ADS)

    Baru, C.; Keller, R.; Wallet, B.; Crosby, C.; Moreland, J.; Nadeau, D.

    2008-12-01

    Currently, many large geoscientific efforts (e.g., EarthScope, Continental Dynamics, and GeoSwath) have emphasized that a crucial need in advancing our understanding of the structure and evolution of the continents is high-resolution, 3-D models of lithospheric structure. In addition, the geoscience community recognizes that our ultimate goal is the addition of the dimension of time to make the problem 4-D. Adding the dimension of time is a complex problem that is strongly dependent on the integration of a variety of geological data into our analyses (e.g., geochronology, paleontology, stratigraphy, pressure-time histories, structural geology, paleogeography, etc.). The geoscience community also recognizes that solutions to the scientific and societal questions that they seek to answer require innovative integration of many types of data so that many physical properties (x, y, z, P-wave velocity, S-wave velocity, density, electrical conductivity, etc.) are measured and included in 3-D models. The problem is, therefore, truly multidimensional in nature. We are developing an Open Earth Framework (OEF) as an open data model for integration of such multidimensional Earth Sciences data. In our work and interactions with the community on building and visualizing complex earth models, several issues have emerged on which there is consensus. First of all, integration efforts should work from the surface down because we have the most data there (e.g., geologic maps, remote sensing data such as LIDAR and ASTER, digital elevation models, gravity and magnetic measurements, etc.) and because the complex conditions near surface always have a potential to mask deeper features. Secondly since we cannot expect uniform coverage of a variety of high-resolution data in anything but special circumstances, a data integration effort should first establish a regional context using lower resolution (and usually wide coverage) data and then proceed to modeling the data sets with the highest

  19. Research Opportunities in Solid Earth Science (RESESS): Broadening Participation in Geology and Geophysics (Invited)

    NASA Astrophysics Data System (ADS)

    Eriksson, S. C.; Hubenthal, M.

    2009-12-01

    RESESS is a multi-year, paid, summer research internship program designed for students from underrepresented groups. The students receive extensive mentoring in science research and communication and become part of a community that provides ongoing support. This has been possible in the initial 5 years of the program through collaboration with Significant Opportunities in Atmospheric Research and Science (SOARS), where solid earth students have been an integral part of the SOARS cohort, benefiting from social as well as educational interactions. 11 students have taken part in RESESS for at least one year and of these, four students have graduated in geoscience and entered graduate programs in geophysics and one was recently awarded an NSF graduate fellowship. Students have presented over 20 posters at national science meetings, and one has co-authored a peer-reviewed article. 23 scientists have mentored students over the past 5 years and 17 percent of these mentors are from underrepresented groups in science; 19 other scientists and university/science consortia staff have mentored students in written and verbal presentations and supported their integration into the local communities. Mentorship over a period of years is one important hallmark of this program as students have benefited from the support of UNAVCO, IRIS, USGS, and university scientists and staff during the summer, academic year, and at professional meetings such as AGU, GSA, NABGG, and SACNAS as well as consortia and project science workshops (UNAVCO, IRIS, and EarthScope). One goal of the project has been to educate the scientific community on the benefits of mentoring undergraduate students from underrepresented groups in STEM fields. Increasingly, scientists are approaching RESESS to include this program in their implementation of broader impacts. RESESS has been funded by NSF for the next five years with plans to expand the number of students, geographic and scientific diversity, and sources of

  20. Geophysics of the solid earth, the moon and the planets. Subvolume a

    NASA Astrophysics Data System (ADS)

    Fuchs, K.; Soffel, H.

    Physical data on the earth as a solid body and on the moon and terrestrial planets are compiled in tables, maps, and diagrams. The theoretical bases of the measurements and the techniques employed in acquiring and processing the data are discussed in the accompanying text. Topics covered include the origin of the earth in the solar system; the motion of the earth; seismicity and the interior of the earth; heat flow, temperature distribution, electrical properties, and composition of the earth interior; tides; the gravity field and figure of the earth; the earth magnetic field; mass transport in the earth interior; and the planetology of the terrestrial planets.

  1. Particle Geophysics

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiroyuki K. M.

    2014-05-01

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

  2. Assessing vulnerability to vegetation growth on earth dikes using geophysical investigation

    NASA Astrophysics Data System (ADS)

    Mary, Benjamin; Saracco, Ginette; Peyras, Laurent; Vennetier, Michel; Mériaux, Patrice

    2015-04-01

    The Mediterranean Basin is prone to a plethora of natural hazards including floods. Vegetation growth in hydraulic earth structures, such as flood protections or channel levees and dams, may induce several degradation mechanisms leading to a risk of failure. Typically, trees' rooting generates two types of risks: internal erosion from root development in earth embankments, and external erosion (slopes and crest) which is often related to trees uprooting. To better assess how woody vegetation can compromise levee integrity, we designed a methodology using acoustical and complex electrical tomography as non destructives methods to spot dangerous roots in the embankment. Our work has been first initiated during laboratory experiments; we performed soundings in controlled conditions to determine both acoustical and electrical intrinsic behavior of our root samples. By comparison with soil samples we expected to point out specific signatures that would be useful for the roots anomaly identification in real conditions. Measurements were repeated on several samples to ensure statistical interpretation. With help of an ultrasonic transmission device, we identified significant relative velocity differences of compressional waves propagation between soil and root samples. We also studied spectral properties using wavelet processing method as an additional parameter of root distinction with the surrounding soil. In the case of electrical soundings, complex resistivity was measured and we computed resistivity spectra. Amplitude of resistivity term showed us that root material behaves as an insulator compared to the soil. With the phase resistivity term information, root can also be seen as an electric power capacitance and reveals maximum polarization effect located around 1Hz. Then, as experimental device for the field measurements, we selected a 320 cm high poplar (Populus) planted in a homogeneous loamy-clayed soil, which is the same soil used in laboratory experiment to

  3. Geophysical disturbance environment during the NASA/MPE barium release at 5 earth radii on September 21, 1971.

    NASA Technical Reports Server (NTRS)

    Davis, T. N.; Stanley, G. M.; Boyd, J. S.

    1973-01-01

    The geophysical disturbance environment was quiet during the NASA/MPE barium release at 5 earth radii on September 21, 1971. At the time of the release, the magnetosphere was in the late recovery phase of a principal magnetic storm, the provisional Dst value was -13 gammas, and the local horizontal disturbance at Great Whale River was near zero. Riometer and other observations indicated low-level widespread precipitation of high-energy electrons at Great Whale River before, during, and after the release. Cloudy sky at this station prevented optical observation of aurora. No magnetic or ionospheric effects attributable to the barium release were detected at Great Whale River.

  4. Geophysical methods

    SciTech Connect

    Robert, E.S.

    1989-01-01

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

  5. Geophysical expression of a buried niobium and rare earth element deposit: the Elk Creek carbonatite, Nebraska, USA

    USGS Publications Warehouse

    Drenth, Benjamin J.

    2014-01-01

    The lower Paleozoic Elk Creek carbonatite is a 6–8-km-diameter intrusive complex buried under 200 m of sedimentary rocks in southeastern Nebraska. It hosts the largest known niobium deposit in the U.S. and a rare earth element (REE) deposit. The carbonatite is composed of several lithologies, the relations of which are poorly understood. Niobium mineralization is most enriched within a magnetite beforsite (MB) unit, and REE oxides are most concentrated in a barite beforsite unit. The carbonatite intrudes Proterozoic country rocks. Efforts to explore the carbonatite have used geophysical data and drilling. A high-resolution airborne gravity gradient and magnetic survey was flown over the carbonatite in 2012. The carbonatite is associated with a roughly annular vertical gravity gradient high and a subdued central low and a central magnetic high surrounded by magnetic field values lower than those over the country rocks. Geophysical, borehole, and physical property data are combined for an interpretation of these signatures. The carbonatite is denser than the country rocks, explaining the gravity gradient high. Most carbonatite lithologies have weaker magnetic susceptibilities than those of the country rocks, explaining why the carbonatite does not produce a magnetic high at its margin. The primary source of the central magnetic high is interpreted to be mafic rocks that are strongly magnetized and are present in large volumes. MB is very dense (mean density 3200  kg/m3) and strongly magnetized (median 0.073 magnetic susceptibility), producing a gravity gradient high and contributing to the aeromagnetic high. Barite beforsite has physical properties similar to most of the carbonatite volume, making it a poor geophysical target. Geophysical anomalies indicate the presence of dense and strongly magnetized rocks at depths below existing boreholes, either a large volume of MB or another unknown lithology.

  6. Assessing landslide movements in volcanic islands using near-shore marine geophysical data: south Pico island, Azores

    NASA Astrophysics Data System (ADS)

    Mitchell, N. C.; Quartau, R.; Madeira, J.

    2011-12-01

    Marine geophysical data can help to resolve whether large-scale instability of an edifice has been geologically recently active. We study such data from the coast of Pico Island where a major slump of Topo volcano has been interpreted from arcuate escarpments and a rugged irregular topography above sea-level. Multibeam sonar data collected immediately offshore show little evidence for slump fault movements, in particular on the island shelf. As the shelf rock platform will have been last modified by surf during the postglacial sea-level transgression, it provides a reference surface of intermediate age (7-19 ky) that can potentially reveal any pre-historic movements. Where the arcuate escarpments are continued offshore, no evidence for active faults are observed where the shelf rock platform crops out in the multibeam data. Elsewhere, mobile shelf sediments may disguise evidence for active faulting so we examined boomer profiles able to image the rock platform beneath them. The data reveal a platform that is steep (6.6 degrees) compared with the dips of platforms around the coast of adjacent Faial Island and steeper than the platform outside the proposed slump. This suggests that it was created by coastal erosion over a shorter period and hence is consistent with a younger coastline age. As with the multibeam data, where escarpments are continued offshore, the rock surface imaged with these boomer data also shows no clear evidence of major slump-related fault displacements. This study therefore illustrates how high-resolution boomer seismic and multibeam data could usefully contribute to hazard assessment of volcanic islands, by helping to evaluate areas with no historical movements.

  7. Geophysical expression of a buried niobium and rare earth element deposit: the Elk Creek carbonatite, Nebraska, USA

    NASA Astrophysics Data System (ADS)

    Drenth, B.; Phillips, J. D.; Kass, A.; Krahenbuhl, R. A.

    2014-12-01

    The lower Paleozoic Elk Creek carbonatite is a 6-8 kilometer diameter intrusive complex buried under 200 meters of sedimentary rocks in southeastern Nebraska. It hosts the largest known niobium deposit in the U.S. and a rare earth element (REE) deposit. The carbonatite is composed of several lithologies, the relations of which are poorly understood. Niobium mineralization is most enriched within a magnetite beforsite unit, and REE oxides are concentrated in a barite beforsite unit. The carbonatite intrudes Proterozoic country rocks. A high-resolution airborne gravity gradient and magnetic survey was flown over the carbonatite in 2012. The carbonatite is associated with an annular vertical gravity gradient high with a subdued central low, and a central magnetic high surrounded by magnetic field values lower than those over the country rocks. Geophysical, borehole, and physical property data are combined for an interpretation of these signatures. The carbonatite is denser than the country rocks, explaining the gravity gradient high. Most carbonatite lithologies have weaker magnetic susceptibilities than those of the country rocks, explaining why the carbonatite produces a magnetic low at its margin. The primary source of the central magnetic high is interpreted to be mafic rocks that are strongly magnetized and are present in large volumes. Magnetite beforsite is very dense (mean density 3200 kg/m3) and strongly magnetized (median 0.073 SI magnetic susceptibility), producing a gravity gradient high and contributing to the aeromagnetic high. Barite beforsite has physical properties similar to most of the carbonatite volume, making it a poor geophysical target. Geophysical anomalies indicate the presence of dense and strongly magnetized rocks at depths below existing boreholes, either a large volume of magnetite beforsite or another unknown lithology. Studies are underway to investigate possible effects of alteration and magnetic remanence, and to better constrain the

  8. Human vertical eye movement responses to earth horizontal pitch

    NASA Technical Reports Server (NTRS)

    Wall, C. 3rd; Petropoulos, A. E.

    1993-01-01

    The vertical eye movements in humans produced in response to head-over-heels constant velocity pitch rotation about a horizontal axis resemble those from other species. At 60 degrees/s these are persistent and tend to have non-reversing slow components that are compensatory to the direction of rotation. In most, but not all subjects, the slow component velocity was well characterized by a rapid build-up followed by an exponential decay to a non-zero baseline. Super-imposed was a cyclic or modulation component whose frequency corresponded to the time for one revolution and whose maximum amplitude occurred during a specific head orientation. All response components (exponential decay, baseline and modulation) were larger during pitch backward compared to pitch forward runs. Decay time constants were shorter during the backward runs, thus, unlike left to right yaw axis rotation, pitch responses display significant asymmetries between paired forward and backward runs.

  9. Geophysical interpretation of satellite laser ranging measurements of crustal movement in California

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.

    1984-01-01

    As determined by satellite laser ranging the rate of contraction of a 900 kilometer baseline between sites located near Quincy in northern California and San Diego in southern California is about 61 to 65 mm/yr with a formal uncertainty of about 10 mm/yr. The measured changes in baseline length are a manifestation of the relative motion between the North America and Pacific tectonic plates. This long baseline result is compared to measurements made by more conventional means on shorter baselines. Additional information based on seismicity, geology, and theoretical modelling is also analyzed. Deformation lying within a few tens of kilometers about the major faults in southern California accounts for most, but not all of the observed motion. Further motion is attributable to a broader scale deformation in southern California. Data suggesting crustal movements north of the Garlock fault, in and near the southern Sierra Nevada and local motion at an observatory are also critically reviewed. The best estimates of overall motion indicated by ground observations lie between 40 and 60 mm/yr. This lies within one or two standard deviations of that deduced by satellite ranging but the possibility of some unresolved deficit cannot be dismissed. The long time scale RM2 plate tectonic model of Minster and Jordan predicts a contraction between 47 and 53 mm/yr depending on the extension rate of the Basin and Range. Thus the ground based observations, satellite laser ranging (SLR) results, and RM2 rates differ at about the 10 mm/yr level and are consistent with one another within the data and model uncertainties.

  10. Geophysical interpretation of satellite laser ranging measurements of crustal movement in California

    NASA Astrophysics Data System (ADS)

    Cohen, Steven C.

    1985-12-01

    As determined by satellite laser ranging the rate of contraction of a 900 km baseline between sites located near Quincy in northern California and San Diego in southern California is about 61-65 mm/yr with a formal uncertainty of about 10 mm/yr (Christodoulidis et al., 1985). The measured changes in baseline length are a manifestation of the relative motion between the North America and Pacific tectonic plates. This long baseline result is compared to measurements made by more conventional means on shorter baselines. Additional information based on seismiscity, geology, and theoretical modelling is also analyzed. Deformation lying within a few tens of kilometers about the major faults in southern California accounts for most, but not all, of the observed motion. Further motion is attributable to a broader-scale deformation in southern California. Data suggesting crustal movements north of the Garlock fault, in and near the southern Sierra Nevada and local motion at an observatory are also critically reviewed. The best estimates of overall motion indicated by ground observations lie between 40 and 60 mm/yr. This lies within one or two standard deviations of that deduced from satellite ranging but the possibility of some unresolved deficit cannot be entirely dismissed. The long time scale RM2 plate tectonic model of Minster and Jordan (1978) predicts a contraction between 47 and 53 mm/yr depending on the extension rate of the Basin and Range. Thus the ground based observations, SLR results, and RM2 rates differ at about the 10 mm/yr level but are not inconsistent with one another within the data and model uncertainties.

  11. Geophysical interpretation of satellite laser ranging measurements of crustal movement in California

    NASA Astrophysics Data System (ADS)

    Cohen, S. C.

    1984-08-01

    As determined by satellite laser ranging the rate of contraction of a 900 kilometer baseline between sites located near Quincy in northern California and San Diego in southern California is about 61 to 65 mm/yr with a formal uncertainty of about 10 mm/yr. The measured changes in baseline length are a manifestation of the relative motion between the North America and Pacific tectonic plates. This long baseline result is compared to measurements made by more conventional means on shorter baselines. Additional information based on seismicity, geology, and theoretical modelling is also analyzed. Deformation lying within a few tens of kilometers about the major faults in southern California accounts for most, but not all of the observed motion. Further motion is attributable to a broader scale deformation in southern California. Data suggesting crustal movements north of the Garlock fault, in and near the southern Sierra Nevada and local motion at an observatory are also critically reviewed. The best estimates of overall motion indicated by ground observations lie between 40 and 60 mm/yr. This lies within one or two standard deviations of that deduced by satellite ranging but the possibility of some unresolved deficit cannot be dismissed. The long time scale RM2 plate tectonic model of Minster and Jordan predicts a contraction between 47 and 53 mm/yr depending on the extension rate of the Basin and Range. Thus the ground based observations, satellite laser ranging (SLR) results, and RM2 rates differ at about the 10 mm/yr level and are consistent with one another within the data and model uncertainties.

  12. Large-scale geophysical and geological-prospecting earth-crust investigation using high-power electromagnetic pulses

    NASA Astrophysics Data System (ADS)

    Velikhov, E. P.; Panchenko, V. P.

    2005-12-01

    The paper presents the concept and physical/technical prerequisites for the use of multi-megawatt electromagnetic pulses created, for instance, by autonomous MHD facilities of short-term operation (3--12 seconds), in fundamental and applied in-depth geophysical and geological research. Location of geological sites and research regions; circuits and parameters of emitting and detecting devices; unique pulse MHD facilities of 10--100 MWe capacity using solid (powder) fuel, created in Russia; conditions and methods of conducting large-scale experiments and trial methodical works, performed in the last 30 years by a cooperative group of Russian institute in various regions of Russia, Kyrghizia and Tajikistan, are described. Results of the following large-scale experiments and methodical works are presented: Oil and gas deposits' searching (Caspian depression, East Siberia); Study of electric conduction of sediments near and on the sea shelf (Kola peninsula); Electrical prospecting of ore deposits at depths of up to 10 km (Kola peninsula); Study of geo-electrical composition (section) of the earth-crust and upper mantle at the Ural (up to 40 km), and in the Baltic (up to 150 km); Forecasting of earthquakes using the effective electric resistance of earth-crust blocks up to 20 km deep (Tajikistan, Kirghizia); Seismic earth-crust "unloading", and changing the time-dependent distribution of the seismic activity under high-power electromagnetic impact; Impact on the ionosphere and spreading of ultra-low-frequency electromagnetic waves emitted by a high-power source. The possibilities and prospects of research dedicated to developing the technologies for electrical prospecting, sorting and outlining hydrocarbon deposits on the shelf, as well as to monitoring and studying the processes occurring in the earth-crust under artificial high-power electromagnetic impact in seismic regions, are discussed.

  13. Tracing sediment movement on semi-arid watershed using Rare Earth Elements 1988

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multi-tracer method employing rare earth elements (REE) was used to determine sediment yield and to track sediment movement in a small semiarid watershed. A 0.33 ha watershed near Tombstone, AZ was divided into five morphological units, each tagged with one of five REE oxides. Relative contributi...

  14. Infrasound as a Geophysical Probe Using Earth as a Venus Analog

    NASA Astrophysics Data System (ADS)

    Komjathy, Attila; Cutts, James; Pauken, Michael; Kedar, Sharon; Smrekar, Suzanne

    2016-10-01

    JPL is in a process of developing an instrument to measure seismic activity on Venus by detecting infrasonic waves in the atmosphere. The overall objective of this research is to demonstrate the feasibility of using sensitive barometers to detect infrasonic signals from seismic and explosive activity on Venus from a balloon platform. Because of Venus' dense atmosphere, seismic signatures from even small quakes (magnitude ~3) are effectively coupled into the atmosphere. The seismic signals are known to couple about 60 times more efficiently into the atmosphere on Venus than on Earth. It was found that almost no attenuation below 80 km on Venus for frequency less than 1Hz. Whereas wind noise is a major source of background noise for terrestrial infrasonic arrays, it is expected that a balloon platform, which drifts with winds will be capable of very sensitive measurements with low noise.In our research we will demonstrate and apply techniques for discriminating upward propagating waves from a seismic event by making measurements with two or more infrasonic sensors using very sensitive barometers on a tether deployed from the balloon in a series of earth-based tests. We will first demonstrate and validate the technique using an artificial infrasound source in a deployment from a hot air balloon on Earth and then extend it with longer duration flights in the troposphere and stratosphere.We will report results on the first flight experiment that will focus on using the barometer instruments on a tethered helium-filled balloon. The balloon flight will be conducted in the vicinity of a known seismic source generated by a seismic hammer. Earlier tests conducted by Sandia National Laboratory demonstrated that this is a highly reproducible source of seismic and acoustic energy using infrasound sensors. The results of the experiments are intended to validate the two-barometer signal processing approach using a well-characterized point signal source.

  15. Spatial coding of eye movements relative to perceived earth and head orientations during static roll tilt

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Paloski, W. H.; Reschke, M. F.

    1998-01-01

    This purpose of this study was to examine the spatial coding of eye movements during static roll tilt (up to +/-45 degrees) relative to perceived earth and head orientations. Binocular videographic recordings obtained in darkness from eight subjects allowed us to quantify the mean deviations in gaze trajectories along both horizontal and vertical coordinates relative to the true earth and head orientations. We found that both variability and curvature of gaze trajectories increased with roll tilt. The trajectories of eye movements made along the perceived earth-horizontal (PEH) were more accurate than movements along the perceived head-horizontal (PHH). The trajectories of both PEH and PHH saccades tended to deviate in the same direction as the head tilt. The deviations in gaze trajectories along the perceived earth-vertical (PEV) and perceived head-vertical (PHV) were both similar to the PHH orientation, except that saccades along the PEV deviated in the opposite direction relative to the head tilt. The magnitude of deviations along the PEV, PHH, and PHV corresponded to perceptual overestimations of roll tilt obtained from verbal reports. Both PEV gaze trajectories and perceptual estimates of tilt orientation were different following clockwise rather than counterclockwise tilt rotation; however, the PEH gaze trajectories were less affected by the direction of tilt rotation. Our results suggest that errors in gaze trajectories along PEV and perceived head orientations increase during roll tilt in a similar way to perceptual errors of tilt orientation. Although PEH and PEV gaze trajectories became nonorthogonal during roll tilt, we conclude that the spatial coding of eye movements during roll tilt is overall more accurate for the perceived earth reference frame than for the perceived head reference frame.

  16. Observed changes in the Earth's dynamic oblateness from GRACE data and geophysical models.

    PubMed

    Sun, Y; Ditmar, P; Riva, R

    A new methodology is proposed to estimate changes in the Earth's dynamic oblateness ([Formula: see text] or equivalently, [Formula: see text]) on a monthly basis. The algorithm uses monthly Gravity Recovery and Climate Experiment (GRACE) gravity solutions, an ocean bottom pressure model and a glacial isostatic adjustment (GIA) model. The resulting time series agree remarkably well with a solution based on satellite laser ranging (SLR) data. Seasonal variations of the obtained time series show little sensitivity to the choice of GRACE solutions. Reducing signal leakage in coastal areas when dealing with GRACE data and accounting for self-attraction and loading effects when dealing with water redistribution in the ocean is crucial in achieving close agreement with the SLR-based solution in terms of de-trended solutions. The obtained trend estimates, on the other hand, may be less accurate due to their dependence on the GIA models, which still carry large uncertainties.

  17. Observed changes in the Earth's dynamic oblateness from GRACE data and geophysical models

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Ditmar, P.; Riva, R.

    2016-01-01

    A new methodology is proposed to estimate changes in the Earth's dynamic oblateness (Δ {J2} or equivalently, -√{5}Δ {C_{20}}) on a monthly basis. The algorithm uses monthly Gravity Recovery and Climate Experiment (GRACE) gravity solutions, an ocean bottom pressure model and a glacial isostatic adjustment (GIA) model. The resulting time series agree remarkably well with a solution based on satellite laser ranging (SLR) data. Seasonal variations of the obtained time series show little sensitivity to the choice of GRACE solutions. Reducing signal leakage in coastal areas when dealing with GRACE data and accounting for self-attraction and loading effects when dealing with water redistribution in the ocean is crucial in achieving close agreement with the SLR-based solution in terms of de-trended solutions. The obtained trend estimates, on the other hand, may be less accurate due to their dependence on the GIA models, which still carry large uncertainties.

  18. The importance of a multidisciplinary approach for solid earth geophysics in Seafloor Observatories data analysis

    NASA Astrophysics Data System (ADS)

    Embriaco, Davide; De Caro, Mariagrazia; De Santis, Angelo; Etiope, Giuseppe; Frugoni, Francesco; Giovanetti, Gabriele; Lo Bue, Nadia; Marinaro, Giuditta; Monna, Stephen; Montuori, Caterina; Sgroi, Tiziana; Beranzoli, Laura; Favali, Paolo

    2016-04-01

    Continuous time-series in deep ocean waters are the basis for an original approach in ocean exploration. The observation of phenomena variability over time is key to understanding many Earth processes, among which: hydrothermal systems, active tectonics, and ecosystem life cycles. Geo-hazards at sea have often been studied with a single-parameter approach on a short time-scale, but it is now becoming clear that to understand these phenomena and, specifically, to identify precursors to very energetic events, such as mega-earthquakes, tsunamis and volcanic eruptions, continuous long-term multiparameter monitoring is strongly needed. In fact, given a signal of interest, by using several sensors recording simultaneously it is possible to identify the contribution of different sources to this signal, and to be less prone to false associations. In Europe, large cabled systems with marine sensors are being developed for near real-time and real-time long-term monitoring of ocean processes within the EMSO (European Multidisciplinary Seafloor and water column Observatory www.emso-eu.org) Research Infrastructure. Obtaining good quality long-term multiparameter data from sensors on-board seafloor observatories, which are the base of a multidisciplinary approach, is a challenging task. We describe the main steps we have taken to retrieve good quality multiparametric data acquired by GEOSTAR class seafloor observatories, both standalone and cabled, deployed at various sites offshore European coast during the last decade. Starting from this data we show the application of a multidisciplinary approach with some examples coming from experiments in EMSO sites.

  19. Using the Earth as a guide to martian mass movement processes: From form to process

    NASA Astrophysics Data System (ADS)

    Lanza, N.; Newsom, H. E.; Osterloo, M. M.; Okubo, C. H.

    2011-12-01

    The discovery of gully features on Mars has led to renewed interest in hillslope processes on that planet, in particular mass movement and the morphologies that it produces. Mass movement is a collection of gravity-driven processes that act to move materials down a hillslope. Here, we examine how mass movements on hillslopes may be expected to differ on Earth and Mars as the result of gravity differences between these planets. Downslope movement of unconsolidated materials is generally controlled by the bulk shear strength of these materials. Although the relationship between gravity and shear strength is largely dependent on variables that are independent of gravity, the lower gravity on Mars is expected to produce some systematic changes in mass movement behaviors that may in turn create morphological features that are observably different from their terrestrial counterparts. After scaling for gravity and modifying empirically derived relationships, we may expect the following differences on martian hillslopes when compared to their terrestrial counterparts: ==On Mars, hillslopes may have steeper angles of repose in fine grained (< ~2 mm) materials, even when dry. No change in angle of repose is expected for larger particles; ==An increase in soil moisture content (e.g., excess pore pressure) is expected to weaken unconsolidated slope materials more on Mars for a particular regolith type, which in turn may produce --An increase in creep rates for a given pore pressure, and --An increase in effectiveness of frost heave to transport materials downslope; ==Processes triggered by saturation may occur at lower pore pressures on Mars; --A smaller amount of fluid is needed to achieve failure; ==Shorter runout lengths are expected for rapid mass movements; ==On Mars, overland flow will exert a proportionally lower shear stress on slope materials; --In cohesive materials, the same volume of water will detach sediments of smaller sizes. On Earth, mass movement processes

  20. Investigation of Karst Cavities and Earth Subsidence with Combined Application of Boring and Geophysics in the Progress of High-Speed Railway Routes

    NASA Astrophysics Data System (ADS)

    Lehmann, Bodo; Pöttler, Rudolf; Radinger, Alexander; Kühne, Manfred

    In Germany there are a lot of new high-speed railways in planning or under construction. One of these is the new Nuremberg - Ingolstadt railway line and the updated line from Ingolstadt to Munich. These two lines will form part of a high-speed trans-European railway link from Scandinavia via Berlin to Munich and Verona. The 78 km railway line construction project has been divided into three contract sections: Contract Section North, mainly characterised by pure earth and bridge works; Contract Section Centre, with the emphasis mainly on tunnel construction; and Contract Section South, combining earthworks and tunnelling. Extensive geophysical investigations combined with borings are carried out in critical areas between Nuremberg and Ingolstadt. The target of this geological exploration phase is mainly the detection of karst pits and earth subsidences (dolines). In this area these geological objects are an important aspect for the stability and permanent serviceability of the high-speed railway routes. The exploration concept on the open stretch consists of combined geological enquiry, geotechnical work, geophysical investigations and borings, which are positioned at the found anomalies of geophysics. The survey leads to a common interpretation of all information and results. After several test campaigns the combination of at least two geophysical methods yields to the best results. Dependent on the thickness of the overburden layer seismics, micro-gravity and/or georadar are applied from the surface. Additionally tomographic methods are used between boreholes for special topics. Important for the success of the investigation in difficult geological areas are the excellent co-operation between all scientists, engineers and technicians (geologists, geotechnicians, geophysicists, driller, consultants, etc.).

  1. WEST COAST REGIONAL CARBON SEQUESTRATION PARTNERSHIP - REPORT ON GEOPHYSICAL TECHNIQUES FOR MONITORING CO2 MOVEMENT DURING SEQUESTRATION

    SciTech Connect

    Gasperikova, Erika; Gasperikova, Erika; Hoversten, G. Michael

    2005-10-01

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

  2. Crisp clustering of airborne geophysical data from the Alto Ligonha pegmatite field, northeastern Mozambique, to predict zones of increased rare earth element potential

    NASA Astrophysics Data System (ADS)

    Eberle, Detlef G.; Daudi, Elias X. F.; Muiuane, Elônio A.; Nyabeze, Peter; Pontavida, Alfredo M.

    2012-01-01

    The National Geology Directorate of Mozambique (DNG) and Maputo-based Eduardo-Mondlane University (UEM) entered a joint venture with the South African Council for Geoscience (CGS) to conduct a case study over the meso-Proterozoic Alto Ligonha pegmatite field in the Zambézia Province of northeastern Mozambique to support the local exploration and mining sectors. Rare-metal minerals, i.e. tantalum and niobium, as well as rare-earth minerals have been mined in the Alto Ligonha pegmatite field since decades, but due to the civil war (1977-1992) production nearly ceased. The Government now strives to promote mining in the region as contribution to poverty alleviation. This study was undertaken to facilitate the extraction of geological information from the high resolution airborne magnetic and radiometric data sets recently acquired through a World Bank funded survey and mapping project. The aim was to generate a value-added map from the airborne geophysical data that is easier to read and use by the exploration and mining industries than mere airborne geophysical grid data or maps. As a first step towards clustering, thorium (Th) and potassium (K) concentrations were determined from the airborne geophysical data as well as apparent magnetic susceptibility and first vertical magnetic gradient data. These four datasets were projected onto a 100 m spaced regular grid to assemble 850,000 four-element (multivariate) sample vectors over the study area. Classification of the sample vectors using crisp clustering based upon the Euclidian distance between sample and class centre provided a (pseudo-) geology map or value-added map, respectively, displaying the spatial distribution of six different classes in the study area. To learn the quality of sample allocation, the degree of membership of each sample vector was determined using a-posterior discriminant analysis. Geophysical ground truth control was essential to allocate geology/geophysical attributes to the six classes

  3. Time-Variable Geophysical Background Models for High-Frequency Non-Tidal Variability in the Earth's Gravity Field, its Surface Deformation, and its Rotation provided by GFZ

    NASA Astrophysics Data System (ADS)

    Dobslaw, Henryk; Dill, Robert; Bergmann-Wolf, Inga; Poropat, Lea; Thomas, Maik

    2016-04-01

    Mass variability in atmosphere, oceans, and the terrestrially stored water is reflected in time variations of the Earth's gravity field, its surface deformations, and its rotation that are reliably picked up by geodetic networks and satellite missions since many years. For studies attempting to unveil signatures of solid Earth processes from such observations, its is highly important to remove signals caused by geophysical fluids on or above the surface as accurately as possible. At this poster, we are going to give a summary about the current status of the time-variable geophysical background models suitable for geodetic purposes that are currently processed at GFZ Potsdam. This will include the latest versions of the GRACE AOD1B background model; effective angular momentum functions for atmosphere, oceans, and the continental hydrosphere; as well as surface deformations due to tidal and non-tidal mass loads on the continents and the ocean floor. Latest news and all access details to the datasets are available at http://www.gfz-potsdam.de/en/section/earthsystemmodelling/services.

  4. Integration of geotechnical and geophysical techniques for the characterization of a small earth-filled canal dyke and the localization of water leakage

    NASA Astrophysics Data System (ADS)

    Bièvre, Grégory; Lacroix, Pascal; Oxarango, Laurent; Goutaland, David; Monnot, Guy; Fargier, Yannick

    2017-04-01

    This paper investigates the combined use of extensive geotechnical, hydrogeological and geophysical techniques to assess a small earth dyke with a permanent hydraulic head, namely a canal embankment. The experimental site was chosen because of known issues regarding internal erosion and piping phenomena. Two leakages were visually located following the emptying of the canal prior to remediation works. The results showed a good agreement between the geophysical imaging techniques (Electrical Resistivity Tomography, P- and SH-waves Tomography) and the geotechnical data to detect the depth to the bedrock and its lateral variations. It appeared that surface waves might not be fully adapted for dyke investigation because of the particular geometry of the studied dyke, non-respectful of the 1D assumption, and which induced depth and velocity discrepancies retrieved from Rayleigh and Love waves inversion. The use of these classical prospecting techniques however did not allow to directly locate the two leakages within the studied earth dyke. The analysis of ambient vibration time series with a modified beam-forming algorithm allowed to localize the most energetic water flow prior to remediation works. It was not possible to detect the leakage after remediation works, suggesting that they efficiently contributed to significantly reduce the water flow. The second leakage was not detected probably because of a non-turbulent water flow, generating few energetic vibrations.

  5. Studies on different geophysical and extra-terrestrial events within the Earth-ionosphere cavity in terms of ULF/ELF/VLF radio waves

    NASA Astrophysics Data System (ADS)

    Sanfui, Minu; Haldar, D. K.; Biswas, Debasish

    2016-10-01

    The space between the two spherical conducting shells, Earth surface and the lower boundary of the ionosphere, behaves as a spherical cavity in which some electromagnetic signals can propagate a long distance and is called Earth-ionosphere waveguide. Through this waveguide ultra low frequency (ULF), extremely low frequency (ELF) and very low frequency (VLF) signals can propagate efficiently with low attenuation. Resonances which occur for ELF waves due to round-the-world propagation interfering with 2n π phase difference are called Schumann resonances. Lightnings are the main sources of energy continuously producing these electromagnetic radiations from the troposphere. Some fixed frequency signals are also transmitted through the waveguide from different stations for navigation purposes. The intensity and phase of these signals at a particular position depend on the waveguide characteristics which are highly influenced by different natural events. Thus the signatures of different geophysical and extra-terrestrial events may be investigated by studying these signals through proper monitoring of the time series data using suitable techniques. In this article, we provide a review on ULF, ELF and VLF signals within the waveguide in terms of different geophysical and extra-terrestrial events like lightning, earthquakes, Leonid meteor shower, solar flares, solar eclipse, geomagnetic storms, and TLEs etc.

  6. Movement.

    ERIC Educational Resources Information Center

    Roberts, Lynda S.

    This document summarizes 20 articles and books which stress the importance of movement in the overall development of the human species. Each summary ranges in length from 100 to 200 words and often includes direct quotations. A wide range of movement activities suitable for people of all ages (from infants to adults) are discussed. Many summaries…

  7. Basic exploration geophysics

    SciTech Connect

    Robinson, E.S.

    1988-01-01

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

  8. Environmental and Engineering Geophysics

    NASA Astrophysics Data System (ADS)

    Sharma, Prem V.

    1997-12-01

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

  9. Subsidence related horizontal earth movements in the Tia Juana field, State of Zulia, Venezuela

    SciTech Connect

    Scherer, W.F.; Pedroza, M.A. )

    1990-05-01

    Subsidence due to oil exploitation in the Bolivar Coast fields in western Venezuela has been monitored since 1926. Related horizontal earth movements have been measured by geodetic methods during the last 10 yr in the northern Tia Juana field area in and around the Ule tank farm and the GLP gas liquefaction plant. Damage to storage tanks and increasing appearance of fractures in the ground in the vicinity of the coastal dyke protection system warranted a detailed study. A surface geologic survey of the Ule area, based initially on aerophotographic interpretation of infrared photographs, flown, on a 1:5,000 scale, showed the area to be divided into blocks by several major faults. These faults were confirmed on the ground by visual inspection, shallow seismic refraction, geoelectric surveys and correlation of geotechnical borings. A geodetic survey of the area with a precision of 5 mm + 2 mm/km for distances, showed significant horizontal displacements of ground markers during an eight-year period. Accordingly, a measuring plan of high-precision (0.015 mm) electromechanic extensometer lines was designed for critical zones across known fault traces and fracture zones. A conceptual model integrates geodetic and extensometer measurements of horizontal movements in the Ule area with the geologic and neotectonic frame of subsurface faults, joining systems, and tensional surface cracks. Rates of Holocene postglacial isostatic adjustments and natural, pre-industry subsidence due to degassing of reservoirs determined by C{sup 14} radiocarbon dating, were used to calculate subsidence rates due to oil exploitation. It was found that the subsidence occurs in the area, not as previously mapped continuous function of compaction, but as discrete, fault and crack limited blocks, governed as much by reactivation of fault slippage as by subsurface compaction.

  10. Movement.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    Focuses on movement: movable art, relocating families, human rights, and trains and cars. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books, additional resources and activities (PEN)

  11. 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.

  12. A geophysical perspective on Earth's mantle water content: Inverting long-period electromagnetic sounding data using laboratory-based electrical conductivity profiles

    NASA Astrophysics Data System (ADS)

    Shankland, T. J.; Khan, A.

    2011-12-01

    We have applied electromagnetic sounding methods for Earth's mantle to constrain its thermal state, chemical composition, and "water" content. We consider long-period inductive response functionsin the form of C-responses from four stations distributed across the Earth (Europe, North America, Asia and Australia) covering a period range from 3.9 to 95.2 days and sensitivity to 1200 km depth. Rather than invert C-responses for conductivity profiles, we invert directly for chemical composition and thermal state using a self-consistent thermodynamic method to compute phase equilibria as functions of pressure, temperature, and composition (in the Na2O-CaO-FeO-MgO-Al2O3-SiO2 model system). Computed mineral modes are combined with recent laboratory-based electrical conductivity models from independent experimental research groups (Yoshino and coworkers and Karato and coworkers) to compute bulk conductivity structure beneath each of the four stations from which C-responses are estimated. This scheme is interfaced with a sampling-based algorithm to solve the resulting non-linear inverse problem. This approach has two advantages: (1) It anchors temperatures, composition, electrical conductivities, and discontinuities that are in laboratory-based forward models, and (2) At the same time it permits the use of geophysical inverse methods to optimize electrical profiles to match geophysical data. The results show variations in upper mantle temperatures beneath the four stations that appear to persist throughout the upper mantle and parts of the transition zone consistent with observations from seismic tomography images that show major lateral velocity variations in the upper mantle. Calculated mantle temperatures at 410 and 660 km depth lie in the range 1250-1650 deg C and 1500-1750 deg C, respectively, and generally agree with experimentally-determined temperatures at which the measured phase reactions olivine->beta-spinel and gamma-spinel->ferropericlase+perovskite occur. The

  13. Core Angular Momentum and the IERS Sub-Centers Activity for Monitoring Global Geophysical Fluids. Part 1; Core Angular Momentum and Earth Rotation

    NASA Technical Reports Server (NTRS)

    Song, Xia-Dong; Chao, Benjamin (Technical Monitor)

    1999-01-01

    The part of the grant was to use recordings of seismic waves travelling through the earth's core (PKP waves) to study the inner core rotation and constraints on possible density anomalies in the fluid core. The shapes and relative arrival times of such waves associated with a common source were used to reduce the uncertainties in source location and excitation and the effect of unknown mantle structure. The major effort of the project is to assemble historical seismograms with long observing base lines. We have found original paper records of SSI earthquakes at COL between 1951 and 1966 in a warehouse of the U.S. Geological Survey office in Golden, Colorado, extending the previous measurements at COL by Song and Richards [1996] further back 15 years. Also in Alaska, the University of Alaska, Fairbanks Geophysical Institute (UAFGI) has been operating the Alaskan Seismic Network with over 100 stations since the late 1960s. Virtually complete archives of seismograms are still available at UAFGI. Unfortunately, most of the archives are in microchip form (develocorders), for which the use of waveforms is impossible. Paper seismograms (helicorders) are available for a limited number of stations, and digital recordings of analog signals started around 1989. Of the paper records obtained, stations at Gilmore Dome (GLM, very close to COL), Yukon (FYU), McKinley (MCK), and Sheep Creek Mountain (SCM) have the most complete continuous recordings.

  14. Landolt-Börnstein. Numerical data and functional relationships inscience and technology. New Series. Group V: Geophysics and space research. Volume 2: Geophysics of the solid earth, the moon and the planets. Subvolume b.

    NASA Astrophysics Data System (ADS)

    Hellwege, K.-H.; Madelung, O.; Fuchs, K.; Soffel, H.; Chapman, D. S.; Lubimova, E. A.; Stacey, F. D.; Schmucker, U.; Haak, V.; Bosum, W.; Pucher, R.; Roeser, H.; Voppel, D.; Busse, F. H.; Hagedorn, H.; Gierloff-Emden, H. G.; Jacoby, W. R.

    Contents: Properties of the solid earth: Continental heat flow data (D. S. Chapman). Temperature profiles in the earth's interior (E. A. Lubimova). Heat transport in the earth's interior (F. D. Stacey). Electrical properties of the earth's interior (U. Schmucker, V. Haak). Magnetic fields of the earth (U. Schmucker, W. Bosum, R. Pucher, H. Roeser, D. Voppel,F. H. Busse, H. Soffel). Transport of masses in the earth's interior: Relief of the earth's surface and of the sea floor (H. Hagedorn, H. G. Gierloff-Emden). Theories and hypothesis of global tectonics (W. R. Jacoby).

  15. Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. Exploration Geophysics

    ERIC Educational Resources Information Center

    Espey, H. R.

    1977-01-01

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

  17. Exploration Geophysics

    ERIC Educational Resources Information Center

    Savit, Carl H.

    1978-01-01

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

  18. Deep mantle structure as a reference frame for movements in and on the Earth.

    PubMed

    Torsvik, Trond H; van der Voo, Rob; Doubrovine, Pavel V; Burke, Kevin; Steinberger, Bernhard; Ashwal, Lewis D; Trønnes, Reidar G; Webb, Susan J; Bull, Abigail L

    2014-06-17

    Earth's residual geoid is dominated by a degree-2 mode, with elevated regions above large low shear-wave velocity provinces on the core-mantle boundary beneath Africa and the Pacific. The edges of these deep mantle bodies, when projected radially to the Earth's surface, correlate with the reconstructed positions of large igneous provinces and kimberlites since Pangea formed about 320 million years ago. Using this surface-to-core-mantle boundary correlation to locate continents in longitude and a novel iterative approach for defining a paleomagnetic reference frame corrected for true polar wander, we have developed a model for absolute plate motion back to earliest Paleozoic time (540 Ma). For the Paleozoic, we have identified six phases of slow, oscillatory true polar wander during which the Earth's axis of minimum moment of inertia was similar to that of Mesozoic times. The rates of Paleozoic true polar wander (<1°/My) are compatible with those in the Mesozoic, but absolute plate velocities are, on average, twice as high. Our reconstructions generate geologically plausible scenarios, with large igneous provinces and kimberlites sourced from the margins of the large low shear-wave velocity provinces, as in Mesozoic and Cenozoic times. This absolute kinematic model suggests that a degree-2 convection mode within the Earth's mantle may have operated throughout the entire Phanerozoic.

  19. The Earth's Shape and Movements: Teachers' Perception of the Relations Between Daily Observation and Scientific Models

    NASA Astrophysics Data System (ADS)

    Ferreira, Flávia Polati; Leite, Cristina

    2015-07-01

    The Earth’s shape and movements are some of the most common issues in official documents and research studies of astronomy education. Many didactic proposals suggest these issues within observational astronomy. Therefore, we present in this paper some of the main results of a research study of the teachers’ perception of the relations between the knowledge from daily observation and scientific models currently accepted about the “earth’s shape and movements”. Data were obtained in application of the didactic proposal during a teacher training course for teachers from São Paulo, have been constructed with the dynamics “Three Pedagogical Moments” and guided by some of the central ideas of the educator Paulo Freire. The results indicate that a small proportion of teachers seem to understand some of the relations of “apparent contradictions” and “limitations” with the concepts of spatiality, and many of them argued based only on vague phrases or "buzzwords", unconnected to the problem explored. The difficulties of teachers to relate elements of daily observation with scientific models seem to indicate a necessity to approach some these aspects with the astronomical knowledge in the teacher training courses.

  20. Reports on crustal movements and deformations. [bibliography

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.; Peck, T.

    1983-01-01

    This Catalog of Reports on Crustal Movements and Deformation is a structured bibliography of scientific papers on the movements of the Earth crust. The catalog summarizes by various subjects papers containing data on the movement of the Earth's surface due to tectonic processes. In preparing the catalog we have included studies of tectonic plate motions, spreading and convergence, microplate rotation, regional crustal deformation strain accumulation and deformations associated with the earthquake cycle, and fault motion. We have also included several papers dealing with models of tectonic plate motion and with crustal stress. Papers which discuss tectonic and geologic history but which do not present rates of movements or deformations and papers which are primarily theoretical analyses have been excluded from the catalog. An index of authors cross-referenced to their publications also appears in the catalog. The catalog covers articles appearing in reviewed technical journals during the years 1970-1981. Although there are citations from about twenty journals most of the items come from the following publications: Journal of Geophysical Research, Tectonophysics, Geological Society of America Bulletin of the Seismological Society of America, Nature, Science, Geophysical Journal of the Royal Astronomical Society, Earth and Planetary Science Letters, and Geology.

  1. Optimization and geophysical inverse problems

    SciTech Connect

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

    2000-10-01

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

  2. Teaching Future Teachers Basic Astronomy Concepts--Sun-Earth-Moon Relative Movements--at a Time of Reform in Science Education

    ERIC Educational Resources Information Center

    Trumper, Ricardo

    2006-01-01

    In view of students' alternative conceptions about basic concepts in astronomy, we conducted a series of constructivist activities with future elementary and junior high school teachers aimed at changing their conceptions about the cause of seasonal changes, and of several characteristics of the Sun-Earth-Moon relative movements like Moon phases,…

  3. A Systematic Review of the Health Impacts of Mass Earth Movements (Landslides)

    PubMed Central

    Kennedy, Iain T R; Petley, Dave N.; Williams, Richard; Murray, Virginia

    2015-01-01

    Background. Mass ground movements (commonly referred to as ‘landslides’) are common natural hazards that can have significant economic, social and health impacts. They occur as single events, or as clusters, and are often part of ‘disaster’ chains, occurring secondary to, or acting as the precursor of other disaster events. Whilst there is a large body of literature on the engineering and geological aspects of landslides, the mortality and morbidity caused by landslides is less well documented. As far as we are aware, this is the first systematic review to examine the health impacts of landslides. Methods. The MEDLINE, EMBASE, CINAHL, SCOPUS databases and the Cochrane library were systematically searched to identify articles which considered the health impacts of landslides. Case studies, case series, primary research and systematic reviews were included. News reports, editorials and non-systematic reviews were excluded. Only articles in English were considered. The references of retrieved papers were searched to identify additional articles. Findings. 913 abstracts were reviewed and 143 full text articles selected for review. A total of 27 papers reporting research studies were included in the review (25 from initial search, 1 from review of references and 1 from personal correspondence). We found a limited number of studies on the physical health consequences of landslides. Only one study provided detail of the causes of mortality and morbidity in relation a landslide event. Landslides cause significant mental health impacts, in particular the prevalence of PTSD may be higher after landslides than other types of disaster, though these studies tend to be older with only 3 papers published in the last 5 years, with 2 being published 20 years ago, and diagnostic criteria have changed since they were produced. Discussion. We were disappointed at the small number of relevant studies, and the generally poor documentation of the health impacts of landslides

  4. A systematic review of the health impacts of mass Earth movements (landslides).

    PubMed

    Kennedy, Iain T R; Petley, Dave N; Williams, Richard; Murray, Virginia

    2015-04-30

    Background. Mass ground movements (commonly referred to as 'landslides') are common natural hazards that can have significant economic, social and health impacts. They occur as single events, or as clusters, and are often part of 'disaster' chains, occurring secondary to, or acting as the precursor of other disaster events. Whilst there is a large body of literature on the engineering and geological aspects of landslides, the mortality and morbidity caused by landslides is less well documented. As far as we are aware, this is the first systematic review to examine the health impacts of landslides. Methods. The MEDLINE, EMBASE, CINAHL, SCOPUS databases and the Cochrane library were systematically searched to identify articles which considered the health impacts of landslides. Case studies, case series, primary research and systematic reviews were included. News reports, editorials and non-systematic reviews were excluded. Only articles in English were considered. The references of retrieved papers were searched to identify additional articles. Findings. 913 abstracts were reviewed and 143 full text articles selected for review. A total of 27 papers reporting research studies were included in the review (25 from initial search, 1 from review of references and 1 from personal correspondence). We found a limited number of studies on the physical health consequences of landslides. Only one study provided detail of the causes of mortality and morbidity in relation a landslide event. Landslides cause significant mental health impacts, in particular the prevalence of PTSD may be higher after landslides than other types of disaster, though these studies tend to be older with only 3 papers published in the last 5 years, with 2 being published 20 years ago, and diagnostic criteria have changed since they were produced. Discussion. We were disappointed at the small number of relevant studies, and the generally poor documentation of the health impacts of landslides. Mental

  5. Terrestrial Planet Geophysics

    NASA Astrophysics Data System (ADS)

    Phillips, R. J.

    2008-12-01

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

  6. Strategies for improving the resolution of electrical and electromagnetic geophysical measurements for three-dimensional inverse modeling of CO2 movement

    NASA Astrophysics Data System (ADS)

    Commer, M.; Kowalsky, M. B.; Dafflon, B.; Wu, Y.; Hubbard, S. S.

    2013-12-01

    Geologic carbon sequestration is being evaluated as a means to mitigate the effects of greenhouse gas emissions. Efforts are underway to identify adequate reservoirs and to evaluate the behavior of injected CO2 over time; time-lapse geophysical methods are considered effective tools for these purposes. Pilot studies have shown that the invasion of CO2 into a background pore fluid can alter the electrical resistivity, with increases from CO2 in the super-critical or gaseous phase, and decreases from CO2 dissolved in groundwater (especially when calcite dissolution is occurring). Because of their sensitivity to resistivity changes, electrical and electromagnetic (EM) methods have been used in such studies for indirectly assessing CO2 saturation changes. While the electrical resistance tomography (ERT) method is a well-established technique for both crosswell and surface applications, its usefulness is limited by the relatively low-resolution information it provides. Controlled-source EM methods, including both frequency-domain and time-domain (transient EM) methods, can offer improved resolution. We report on three studies that aim to maximize the information content of electrical and electromagnetic measurements in inverse modeling applications that target the monitoring of resistivity changes due to CO2 migration and/or leakage. The first study considers a three-dimensional crosswell data set collected at an analogue site used for investigating CO2 distribution and geochemical reactivity within a shallow formation. We invert both resistance and phase data using a gradient-weighting method for descent-based inversion algorithms. This method essentially steers the search direction in the model space using low-cost non-linear conjugate gradient methods towards the more computationally expensive Gauss-Newton direction. The second study involves ERT data that were collected at the SECARB Cranfield site near Natchez, Mississippi, at depths exceeding 3000 m. We employ a

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

    USGS Publications Warehouse

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

    2008-01-01

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

  8. On the similarity of 239Pu α-activity histograms when the angular velocities of the Earth diurnal rotation, orbital movement and rotation of collimators are equalized

    NASA Astrophysics Data System (ADS)

    Shnoll, S. E.; Rubinstein, I. A.; Shapovalov, S. N.; Tolokonnikova, A. A.; Shlektaryov, V. A.; Kolombet, V. A.; Kondrashova, M. N.

    2016-01-01

    It was shown earlier that the persistent "scatter" of results of measurements of any nature is determined by the diurnal and orbital movement of the Earth. The movement is accompanied by "macroscopic fluctuations" (MF)—regular, periodic changes in the shape of histograms, spectra of fluctuation amplitudes of the measured parameters. There are two near-daily periods ("sidereal", 1436 min; and "solar", 1440 min) and three yearly ones ("calendar", 365 average solar days; "tropical", 365 days 5 h and 48 min; and "sidereal", 365 days 6 h and 9 min). This periodicity was explained by the objects whose parameters are measured passing through the same spatial-temporal heterogeneities as the Earth rotates and shifts along its orbit.

  9. Serious games for Geophysics

    NASA Astrophysics Data System (ADS)

    Lombardo, Valerio; Rubbia, Giuliana

    2015-04-01

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

  10. Continental crust: a geophysical approach

    SciTech Connect

    Meissner, R.

    1986-01-01

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

  11. Studies in geophysics: Active tectonics

    NASA Technical Reports Server (NTRS)

    1986-01-01

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

  12. Geophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Busse, F. H.

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

  13. Geophysics of Mars

    NASA Technical Reports Server (NTRS)

    Wells, R. A.

    1979-01-01

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

  14. Geophysical Sounding

    NASA Astrophysics Data System (ADS)

    Blake, E.

    1998-01-01

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

  15. 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.

  16. 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

  17. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

  18. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

  19. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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

  20. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  1. 15 CFR 950.5 - National Geophysical and Solar-Terrestrial Data Center (NGSDC).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  2. Great Lakes Climate and Water Movement. Earth Systems - Education Activities for Great Lakes Schools (ES-EAGLS).

    ERIC Educational Resources Information Center

    Miller, Heidi, Ed.; Sheaffer, Amy L., Ed.

    This activity book is part of a series designed to take a concept or idea from the existing school curriculum and develop it in the context of the Great Lakes using teaching approaches and materials appropriate for students in middle and high school. The theme of this book is Great Lakes climate and water movement. Students learn about land-sea…

  3. Developing a curricular module for introductory geophysics or structural geology courses to quantify crustal strain using EarthScope PBO GPS velocities

    NASA Astrophysics Data System (ADS)

    Cronin, V. S.; Resor, P. G.; Hammond, W. C.; Kreemer, C. W.; Olds, S. E.; Pratt-Sitaula, B.; West, N. W.

    2012-12-01

    A group from several UNAVCO-member institutions that are engaged in EarthScope research is developing resources that introduce geoscience majors to one important use of GPS geodesy: measuring the current infinitesimal strain rate of the crust. These resources will be tested during the 2012-13 academic year, and will be accessible from the Science Education Resource Center (SERC), UNAVCO and EarthScope websites. Location and velocity data (and their associated uncertainties) from the EarthScope Plate Boundary Observatory (PBO) website are used to solve a perfectly constrained problem involving the infinitesimal strain of a triangle defined by three PBO GPS sites. Simple physical models made of inexpensive materials are used to build student intuition about homogeneous strain of a continuum. Introductory exercises with vector-field maps are used to help students understand reference frames and visualize how GPS velocity vectors can indicate crustal strain. The meanings of "extension" and "stretch" are developed through illustrations showing the simultaneous deformation of a triangle with a circle inscribed within it. A strain primer, intended to supplement textbook material, is provided for students to develop needed background. Supplemental material about vectors, vector dot products, matrix mathematics, determinants, and computation of the eigensystem of a symmetric square matrix help support students who have gaps in their mathematical background. Students compute site velocities and uncertainties from PBO data, insert data into one of three strain calculators (open-source code in MatLab, Mathematica, and an Excel spreadsheet), and learn to interpret the output. A complete algorithm and worked example are also provided so that capable students can develop their own code to solve the problem. Strain calculator output includes the mean translation velocity vector, the rotational velocity, the relative magnitudes and directions of the horizontal infinitesimal strain

  4. Air-depolyable geophysics package

    SciTech Connect

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

    1993-11-01

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

  5. Pointing losses in single-axis and fixed-mount earth-station antennas due to satellite movement

    NASA Astrophysics Data System (ADS)

    Buchsbaum, L. M.

    1986-06-01

    There are substantial cost advantages in the use of single-axis or fixed-mount earth-station antennas, thus reducing or eliminating the need for autotracking in earth-stations operating with quasi-stationary satellites. Such cost advantages are more relevant in small antennas where the tracking system represents a larger percentage of the overall cost. In addition, small antennas are particularly suitable to be operated without autotracking, owing to their wider half-power beamwidth. This paper describes a model for calculating the antenna pointing loss as a function of the antenna diameter, operating frequency band, satellite station-keeping tolerances, and the relative geometry between the earth-station and the satellite. The model has been extensively used in the development of Intelsat's IBS and VISTA services as well as in domestic leases. Although the model has been developed based on orbital mechanics equations, its emphasis is towards earth-station and systems engineering applications. Some example calculations and results obtained through an HP-41 CV programmable calculator are also provided.

  6. Handbook of Agricultural Geophysics

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Earth Rotation

    NASA Technical Reports Server (NTRS)

    Dickey, Jean O.

    1995-01-01

    The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

  8. Geophysical interpretation of U, Th, and rare earth element mineralization of the Bokan Mountain peralkaline granite complex, Prince of Wales Island, southeast Alaska

    USGS Publications Warehouse

    McCafferty, Anne E.; Stoeser, Douglas B.; Van Gosen, Bradley S.

    2014-01-01

    A prospectivity map for rare earth element (REE) mineralization at the Bokan Mountain peralkaline granite complex, Prince of Wales Island, southeastern Alaska, was calculated from high-resolution airborne gamma-ray data. The map displays areas with similar radioelement concentrations as those over the Dotson REE-vein-dike system, which is characterized by moderately high %K, eU, and eTh (%K, percent potassium; eU, equivalent parts per million uranium; and eTh, equivalent parts per million thorium). Gamma-ray concentrations of rocks that share a similar range as those over the Dotson zone are inferred to locate high concentrations of REE-bearing minerals. An approximately 1300-m-long prospective tract corresponds to shallowly exposed locations of the Dotson zone. Prospective areas of REE mineralization also occur in continuous swaths along the outer edge of the pluton, over known but undeveloped REE occurrences, and within discrete regions in the older Paleozoic country rocks. Detailed mineralogical examinations of samples from the Dotson zone provide a means to understand the possible causes of the airborne Th and U anomalies and their relation to REE minerals. Thorium is sited primarily in thorite. Uranium also occurs in thorite and in a complex suite of ±Ti±Nb±Y oxide minerals, which include fergusonite, polycrase, and aeschynite. These oxides, along with Y-silicates, are the chief heavy REE (HREE)-bearing minerals. Hence, the eU anomalies, in particular, may indicate other occurrences of similar HREE-enrichment. Uranium and Th chemistry along the Dotson zone showed elevated U and total REEs east of the Camp Creek fault, which suggested the potential for increased HREEs based on their association with U-oxide minerals. A uranium prospectivity map, based on signatures present over the Ross-Adams mine area, was characterized by extremely high radioelement values. Known uranium deposits were identified in the U-prospectivity map, but the largest tract occurs

  9. Progress in geophysical fluid dynamics

    NASA Astrophysics Data System (ADS)

    Robinson, Allan R.

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

  10. The physics of the earth's core: An introduction

    SciTech Connect

    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.

  11. 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.

  12. Mass Transport in Global Geophysical Fluids

    NASA Technical Reports Server (NTRS)

    Chao, B. F.

    1999-01-01

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

  13. EDITORIAL: The interface between geophysics and engineering

    NASA Astrophysics Data System (ADS)

    2004-03-01

    Journal of Geophysics and Engineering (JGE) aims to publicize and promote research and developments in geophysics and in related areas of engineering. As stated in the journal scope, JGE is positioned to bridge the gap between earth physics and geo-engineering, where it reflects a growing trend in both industry and academia. JGE covers those aspects of engineering that bear closely on geophysics or on the targets and problems that geophysics addresses. Typically this will be engineering focused on the subsurface, particularly petroleum engineering, rock mechanics, geophysical software engineering, drilling technology, remote sensing, instrumentation and sensor design. There is a trend, visible throughout academia, for rapid expansion in cross-disciplinary, multi-disciplinary and inter-disciplinary working. Many of the most important and exciting problems and advances are being made at the boundaries between traditional subject areas and, increasingly, techniques from one discipline are finding applications in others. There is a corresponding increasing requirement for researchers to be aware of developments in adjacent areas and for papers published in one area to be readily accessible, both in terms of location and language, to those in others. One such area that is expanding rapidly is that at the interface between geophysics and engineering. There are three principal developments. Geophysics, and especially applied geophysics, is increasingly constrained by the limits of technology, particularly computing technology. Consequently, major advances in geophysics are often predicated upon major developments in engineering and many research geophysicists are working in multi-disciplinary teams with engineers. Engineering problems relevant to the sub-surface are increasingly looking to advances in geophysics to provide part of the solution. Engineering systems, for example, for tunnel boring or petroleum reservoir management, are using high-resolution geophysical

  14. Earth-Fissure Movements Associated with Fluctuations in Ground-Water Levels near the Picacho Mountains, South-Central Arizona, 1980-84

    USGS Publications Warehouse

    Carpenter, M.C.

    1993-01-01

    The Picacho earth fissure transects subsiding alluvial sediments near the east periphery of the Picacho basin in south-central Arizona. The basin has undergone land subsidence of as much as 3.8 meters since the 1930's owing to compaction of the aquifer system in response to ground-water-Ievel declines that have exceeded 100 meters. The fissure, which extends generally north-south for 15 kilometers, exhibits horizontal tensile failure and as much as 0.6 meter of normal dip-slip movement at the land surface. The west side of the fissure is down thrown. The fissure was observed as early as 1927 and is the longest earth fissure in Arizona. Vertical and horizontal displacements were monitored along a line normal to the fissure. The survey line extends from a bedrock outcrop in the Picacho Mountains on the east, past an observation well near the fissure, to a point 1,422 meters to the west. From May 1980 to May 1984, the downthrown west side of the fissure subsided 167+-1.8 millimeters and moved 18+-1.5 millimeters westward into the basin. Concurrently, the relatively upthrown east side subsided 148+-1.8 millimeters and moved 14+-1.5 millimeters westward. Dislocation modeling of deformation along the survey line near the fissure indicates that dip-slip movement has occurred along a vertical fault surface that extends from the land surface to a depth of about 300 meters. Slip was 9 millimeters from May to December 1980 and also 9 millimeters from March to November 1981. Continuous measurements were made of horizontal movement across the fissure using a buried invar-wire horizontal extensometer, while water-level fluctuations were continuously monitored in four piezometers nested in two observation wells. The range of horizontal movement was 4.620 millimeters, and the range of water-level fluctuation in the nearest piezometer in the deep alluvium was 9.05 meters. The maximum annual opening of the fissure during the study period was 3.740 millimeters from March to October

  15. Fiber optic geophysical sensors

    DOEpatents

    Homuth, Emil F.

    1991-01-01

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

  16. Monitoring Global Geophysical Fluids by Space Geodesy

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  17. Non-Seismic Geophysical Approaches to Monitoring

    SciTech Connect

    Hoversten, G.M.; Gasperikova, Erika

    2004-09-01

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

  18. Multiscale geophysical imaging of the critical zone

    NASA Astrophysics Data System (ADS)

    Parsekian, A. D.; Singha, K.; Minsley, B. J.; Holbrook, W. S.; Slater, L.

    2015-03-01

    Details of Earth's shallow subsurface—a key component of the critical zone (CZ)—are largely obscured because making direct observations with sufficient density to capture natural characteristic spatial variability in physical properties is difficult. Yet this inaccessible region of the CZ is fundamental to processes that support ecosystems, society, and the environment. Geophysical methods provide a means for remotely examining CZ form and function over length scales that span centimeters to kilometers. Here we present a review highlighting the application of geophysical methods to CZ science research questions. In particular, we consider the application of geophysical methods to map the geometry of structural features such as regolith thickness, lithological boundaries, permafrost extent, snow thickness, or shallow root zones. Combined with knowledge of structure, we discuss how geophysical observations are used to understand CZ processes. Fluxes between snow, surface water, and groundwater affect weathering, groundwater resources, and chemical and nutrient exports to rivers. The exchange of gas between soil and the atmosphere have been studied using geophysical methods in wetland areas. Indirect geophysical methods are a natural and necessary complement to direct observations obtained by drilling or field mapping. Direct measurements should be used to calibrate geophysical estimates, which can then be used to extrapolate interpretations over larger areas or to monitor changing processes over time. Advances in geophysical instrumentation and computational approaches for integrating different types of data have great potential to fill gaps in our understanding of the shallow subsurface portion of the CZ and should be integrated where possible in future CZ research.

  19. Earth and ocean modeling

    NASA Technical Reports Server (NTRS)

    Knezovich, F. M.

    1976-01-01

    A modular structured system of computer programs is presented utilizing earth and ocean dynamical data keyed to finitely defined parameters. The model is an assemblage of mathematical algorithms with an inherent capability of maturation with progressive improvements in observational data frequencies, accuracies and scopes. The Eom in its present state is a first-order approach to a geophysical model of the earth's dynamics.

  20. The Physics of Heavy Oils: Implications for Recovery and Geophysical Monitoring

    NASA Astrophysics Data System (ADS)

    Schmitt, Douglas

    2007-03-01

    Our capacity to find and produce conventional light petroleum oils are unable to keep pace with the growth in the growing global demand for energy. With the breakpoint between petroleum production and consumption imminent, a good deal of recent efforts have focused on developing the `heavy' hydrocarbon reserves. Such resources include the extensive heavy oil deposits of Venezuela, the bitumen resources of Canada, and even the solid kerogens (oil shale) of the United States. Capital investments, in particular, have been large in Canada's oil sands due in part to the extensive nature of the resource and already in excess of 30% of Canada's production comes from heavier hydrocarbon deposits. The larger input costs associated with such projects, however, requires that the production be monitored more fully; and this necessitates that both the oils and the porous media which hold them be understood. Geophysical `time-lapse' monitoring seeks to better constrain the areal distribution and movements of fluids in the subsurface by examining the changes in a geophysical response such as seismic reflectivity, micro-gravity variations, or electrical conductivity that arise during production. For example, a changed geophysical seismic character directly depends on relies on variations in the longitudinal and transverse wave speeds and attenuation and mass densities of the materials in the earth. These are controlled by a number of extrinsic conditions such as temperature, fluid pressure, confining stress, and fluid phase and saturation state. Understanding the geophysical signature over a given reservoir requires that the behavior of the porous rock physical properties be well understood and a variety of measurements are being made in laboratories. In current practice, the interpretation of the geophysical field responses is assisted by combined modeling of fluid flow and seismic wave fields. The least understood link in this process, however, is the lack of knowledge on rock

  1. Geophysics in INSPIRE

    NASA Astrophysics Data System (ADS)

    Sőrés, László

    2013-04-01

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

  2. 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

  3. Geophysical Institute biennial report 1995--1996

    SciTech Connect

    1998-06-01

    The mission of the Geophysical Institute is to understand the basic physical processes governing Earth, especially as they occur in, or are relevant to the Arctic; to train graduate and undergraduate students to play leading roles in tomorrow`s society; to solve applied geophysical problems and develop resource-oriented technology of importance to the state and the nation; and to satisfy the intellectual and technological needs of fellow Alaskans through public service. The variety of subjects studied by the faculty, research staff members, and graduate students at the Geophysical Institute include auroral physics and chemistry, arctic haze, ice fog, atmospheric dynamics, ozone, Alaska weather patterns, regional meteorology and climatology, global climate change, cloud physics and radiation, permafrost, glaciers, sea ice, remote sensing, geothermal energy, tectonics, volcanoes and earthquakes. Summaries are presented of the projects undertaken by the Institute in these fields.

  4. High temperature geophysical instrumentation

    SciTech Connect

    Hardee, H.C.

    1988-06-01

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

  5. Fiber optic geophysical sensors

    DOEpatents

    Homuth, E.F.

    1991-03-19

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

  6. Geophysical Models for Nuclear Explosion Monitoring

    SciTech Connect

    Pasyanos, M E; Walter, W R; Flanagan, M

    2003-07-16

    Geophysical models are increasingly recognized as an important component of regional calibrations for seismic monitoring. The models can be used to predict geophysical measurements, such as body wave travel times, and can be derived from direct regional studies or even by geophysical analogy. While empirical measurements of these geophysical parameters might be preferred, in aseismic regions or regions without seismic stations, this data might not exist. In these cases, models represent a 'best guess' of the seismic properties in a region, which improves on global models such as the PREM (Preliminary Reference Earth Model) or the IASPEI (International Association of Seismology and Physics of the Earth's Interior) models. The model-based predictions can also serve as a useful background for the empirical measurements by removing trends in the data. To this end, Lawrence Livermore National Laboratory (LLNL) has developed the WENA model for Western Eurasia and North Africa. This model is constructed using a regionalization of several dozen lithospheric (crust and uppermost mantle) models, combined with the Laske sediment model and 3SMAC upper mantle. We have evaluated this model using a number of data sets, including travel times, surface waves, receiver functions, and waveform analysis. Similarly, Los Alamos National Laboratory (LANL) has developed a geophysical model for East Asia, allowing LLNL/LANL to construct a model for all of Eurasia and North Africa. These models continue to evolve as new and updated datasets are used to critically assess the predictive powers of the model. Research results from this meeting and other reports and papers can be used to update and refine the regional boundaries and regional models. A number of other groups involved in monitoring have also developed geophysical models. As these become available, we will be assessing the models and their constitutive components for their suitability for inclusion in the National Nuclear Security

  7. Magnetic field of the Earth

    NASA Astrophysics Data System (ADS)

    Popov, Aleksey

    2013-04-01

    The magnetic field of the Earth has global meaning for a life on the Earth. The world geophysical science explains: - occurrence of a magnetic field of the Earth it is transformation of kinetic energy of movements of the fused iron in the liquid core of Earth - into the magnetic energy; - the warming up of a kernel of the Earth occurs due to radioactive disintegration of elements, with excretion of thermal energy. The world science does not define the reasons: - drift of a magnetic dipole on 0,2 a year to the West; - drift of lithospheric slabs and continents. The author offers: an alternative variant existing in a world science the theories "Geodynamo" - it is the theory « the Magnetic field of the Earth », created on the basis of physical laws. Education of a magnetic field of the Earth occurs at moving the electric charge located in a liquid kernel, at rotation of the Earth. At calculation of a magnetic field is used law the Bio Savara for a ring electric current: dB = . Magnetic induction in a kernel of the Earth: B = 2,58 Gs. According to the law of electromagnetic induction the Faradey, rotation of a iron kernel of the Earth in magnetic field causes occurrence of an electric field Emf which moves electrons from the center of a kernel towards the mantle. So of arise the radial electric currents. The magnetic field amplifies the iron of mantle and a kernel of the Earth. As a result of action of a radial electric field the electrons will flow from the center of a kernel in a layer of an electric charge. The central part of a kernel represents the field with a positive electric charge, which creates inverse magnetic field Binv and Emfinv When ?mfinv = ?mf ; ?inv = B, there will be an inversion a magnetic field of the Earth. It is a fact: drift of a magnetic dipole of the Earth in the western direction approximately 0,2 longitude, into a year. Radial electric currents a actions with the basic magnetic field of a Earth - it turn a kernel. It coincides with laws

  8. Global Change Geodesy: A Geophysical Perspective

    NASA Astrophysics Data System (ADS)

    Mitrovica, J. X.

    2014-12-01

    It is a truism that as the precision of geodetic measurement techniques improves, the accuracy of the geophysical modeling of processes that contribute to the observations must keep pace. Studies of the Earth's response to human-induced climate change provide many notable, and pressing, illustrations of this axiom. For example, estimates of recent ice volume changes, as inferred from satellite gravity measurements, tide gauge and satellite-altimetry records of sea level changes, or astronomical and space-geodetic constraints on Earth rotation, require improved theoretical and numerical treatments of ongoing glacial isostatic adjustment in response to the last ice age. However, the interplay between geodesy and geophysics is not a one-way street; geophysical modeling has emphasized, for example, that the geographic variability in sea level measurements - once considered a nuisance in efforts to infer long term trends - provides a powerful constraint on both the individual sources of meltwater and their sum. In this talk, I will discuss a series of case studies that demonstrate how interdisciplinary research at the interface between geodesy and geophysics has recently resolved several outstanding problems in global change research, including Walter Munk's enigma of global sea-level rise and the apparent failure to close the budget of twentieth century sea level. Moreover, in the same interdisciplinary context, I will highlight uncertainties that currently limit our understanding of polar ice sheet stability in a progressively warming world.

  9. Earth materials and earth dynamics

    SciTech Connect

    Bennett, K; Shankland, T.

    2000-11-01

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  10. Looking into the Earth

    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

  11. Phillips Laboratory Geophysics Scholar Program

    DTIC Science & Technology

    1993-09-30

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

  12. Geophysical and atmospheric evolution of habitable planets.

    PubMed

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

    2010-01-01

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

  13. Identification and Description of Geophysical Techniques.

    DTIC Science & Technology

    1980-11-01

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

  14. Strainmeters and tiltmeters in geophysics

    NASA Technical Reports Server (NTRS)

    Goulty, N. R.

    1976-01-01

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

  15. Fractals in geology and geophysics

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald L.

    1989-01-01

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

  16. Global Geophysical Fluids Center of IERS

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  17. Surface exploration geophysics applied to the moon

    SciTech Connect

    Ander, M.E.

    1984-01-01

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

  18. Geophysical Fiber Interferometer Gyroscope.

    DTIC Science & Technology

    1979-12-31

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

  19. Teaching oriented geophysical software

    NASA Astrophysics Data System (ADS)

    Pinto, Victor; Rivero, Lluis; Casas, Albert

    2000-08-01

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

  20. Fundamentals of Geophysical Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    McWilliams, James C.

    2006-07-01

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

  1. Geophysics News 1990

    NASA Astrophysics Data System (ADS)

    Cole, Stephen

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

  2. Information Theory and the Earth's Density Distribution

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1979-01-01

    An argument for using the information theory approach as an inference technique in solid earth geophysics. A spherically symmetric density distribution is derived as an example of the method. A simple model of the earth plus knowledge of its mass and moment of inertia lead to a density distribution which was surprisingly close to the optimum distribution. Future directions for the information theory approach in solid earth geophysics as well as its strengths and weaknesses are discussed.

  3. Information theory and the earth's density distribution

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1978-01-01

    The present paper argues for using the information theory approach as an inference technique in solid earth geophysics. A spherically symmetric density distribution is derived as an example of the method. A simple model of the earth plus knowledge of its mass and moment of inertia leads to a density distribution. Future directions for the information theory approach in solid earth geophysics as well as its strengths and weaknesses are discussed.

  4. 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

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

    EPA Science Inventory

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

    ...

  6. 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.

  7. Asteroid Surface Geophysics

    NASA Astrophysics Data System (ADS)

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

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

  8. Movement Disorders

    MedlinePlus

    ... t want them to. If you have a movement disorder, you experience these kinds of impaired movement. Dyskinesia ... movement and is a common symptom of many movement disorders. Tremors are a type of dyskinesia. Nerve diseases ...

  9. Crustal movement and plate motion as observed by GPS baseline ranging - trial to make teaching materials for middle- and high-school earth science education by teachers

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.

    2009-12-01

    Japanese government established the system for renewing educational personnel certificates in 2007 and mandated the adoption of it in April 2009 (cf. “2007 White Paper on Education, Culture, Sports, Science and Technology”, available at http://www.mext.go.jp/english/). The new system shows that the valid period for each regular certificate after the renewal system adoption (April 1, 2009) is until the end of the fiscal year after ten years from satisfying the qualifications required for the certificate. Only persons who have attended over 30 hours and passed the examination in the certificate renewal courses before the expiration of the valid period can renew their certificate which is valid for next ten years. The purpose of this system is for teachers to acquire the latest knowledge and skills. Certificate renewal courses authorized by Ministry of Education, Culture, Sports, Science and Technology of Japan are offered by universities. Attendees will choose based on their specialty and awareness of issues from the various courses with education curriculums and. To renew their certificates, they should include (1) items regarding the latest trends and issues in education (12 hours) and (2) items regarding their speciality and other educational enhancement (three 6-hours course: total 18 hours). In 2008, before the adoption, provisional certificate renewal courses were offered for trial by more than 100 universities. The author offered a 6-hour course titled by “Development of teaching materials for school pupils to make understand the dynamic motion of the earth - utilising the results of the GPS ranging”. This course was targeted mainly for science teachers of middle- and high-schools. The goal of this course was for the attendees to understand the role of GPS ranging for the direct observation of the crustal movement and plate motion, and to produce the teaching materials possibly used in the classrooms. The offering of this course is aiming finally at

  10. Time-reversal methods in geophysics

    SciTech Connect

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

    2010-08-15

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

  11. Large natural geophysical events: planetary planning

    SciTech Connect

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

    1984-09-01

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

  12. Guided earth boring tool

    SciTech Connect

    McDonald, W.J.; Pittard, G.T.; Maurer, W.C.; Wasson, M.R.; Herben, W.C.

    1989-08-22

    This patent describes a controllable tool for drilling holes in soft earth. The tool comprising an elongated rigid supporting drill rod or pipe, means supporting the drill rod or pipe for earth boring or piercing movement, including means for moving the drill rod or pipe longitudinally for penetrating the earth, means for rotating the drill rod or pipe while penetrating the earth, and means for controlling the direction of movement of the drill rod or pipe along a straight or curved path. The drill rod or pipe moving and rotating means being constructed to permit addition and removal of supporting drill rod or pipe during earth penetrating operation, an earth piercing member of substantially cylindrical shape. The tool being operable to penetrate the earth upon longitudinal movement of the drill rod or pipe by the longitudinal rod or pipe moving means, and the direction controlling means comprising means causing drill rod or pipe movement in a curved path through the earth when the rod or pipe is not rotated and causing drill rod or pipe straight line movement when the rod or pipe is rotated.

  13. Geophysics publications honored

    NASA Astrophysics Data System (ADS)

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

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

    PubMed Central

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Vallis, Geoffrey K.

    2016-08-01

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

  16. 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

  17. A Directory of Societies in Earth Science.

    ERIC Educational Resources Information Center

    Geotimes, 1981

    1981-01-01

    Lists the titles and addresses of approximately 450 domestic and foreign organizations which deal with earth science fields, including geology, paleontology, mining, and geophysics. Also listed are U.S. state geological surveys. (WB)

  18. Geophysics and cosmogony of solar system

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

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

  19. Sampling functions for geophysics

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  20. Prediction of Geophysical Flow Mobility

    NASA Astrophysics Data System (ADS)

    Cagnoli, B.; Piersanti, A.

    2014-12-01

    The prediction of the mobility of geophysical flows to assess their hazards is one of the main research goals in the earth sciences. Our laboratory experiments and numerical simulations are carried out to understand the effects of grain size and flow volume on the mobility of the centre of mass of dry granular flows of angular rock fragments that have pyroclastic flows and rock avalanches as counterpart in nature. We focus on the centre of mass because it provides information about the intrinsic ability of a flow to dissipate more or less energy as a function of its own features. We show that the grain size and flow volume effects can be expressed by a linear relationship between scaling parameters where the finer the grain size or the smaller the flow volume, the more mobile the centre of mass of the granular flow. The grain size effect is the result of the decrease of particle agitation per unit of flow mass, and thus, the decrease of energy dissipation per unit of travel distance, as grain size decreases. In this sense, flows with different grain sizes are like cars with engines with different fuel efficiencies. The volume effect is the result of the fact that the deposit accretes backward during its formation on a slope change (either gradual or abrupt). We adopt for the numerical simulations a 3D discrete element modeling which confirms the grain size and flow volume effects shown by the laboratory experiments. This confirmation is obtained without prior fine tuning of the parameter values to get the desired output. The numerical simulations reveal also that the larger the initial compaction of the granular mass before release, the more mobile the flow. This behaviour must be taken into account to prevent misinterpretation of laboratory and field data. Discrete element modeling predicts the correct effects of grain size and flow volume because it takes into consideration particle interactions that are responsible for the energy dissipated by the flows.

  1. Satellite-tracking and Earth dynamics research programs

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Tracking of LAGEOS for polar motion and Earth rotation studies and for other geophysical investigations, including crustal dynamics, Earth and ocean tides, and the general development of precision orbit determination continues. The BE-C and Starlette satellites were tracked for refined determinations of station coordinates and the Earth's gravity field and for studies of solid Earth dynamics.

  2. Space Geodesy Monitoring Mass Transport in Global Geophysical Fluids

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

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

  3. Jesuit Geophysical Observatories

    NASA Astrophysics Data System (ADS)

    Udias, Agustin; Stauder, William

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

  4. A ``model`` geophysics program

    SciTech Connect

    Nyquist, J.E.

    1994-03-01

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

  5. Inversion Algorithms for Geophysical Problems

    DTIC Science & Technology

    1987-12-16

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

  6. Marine Geophysics: a Navy Symposium

    DTIC Science & Technology

    1987-09-01

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

  7. Monitoring Vadose Zone Desiccation with Geophysical Methods

    SciTech Connect

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

    2013-05-01

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

  8. Planetary Geophysics and Tectonics

    NASA Technical Reports Server (NTRS)

    Zuber, Maria

    2005-01-01

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

  9. Dunlop receives European Geophysical Society's Néel Medal

    NASA Astrophysics Data System (ADS)

    Tauxe, Lisa

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

  10. Comparison of different models of geophysical excitation in nutation

    NASA Astrophysics Data System (ADS)

    Ron, Cyril; Vondrák, Jan

    2015-04-01

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

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

    SciTech Connect

    1995-12-31

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

  12. 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

  13. Bowel Movement

    MedlinePlus

    A bowel movement is the last stop in the movement of food through your digestive tract. Your stool passes out ... rectum and anus. Another name for stool is feces. It is made of what is left after ...

  14. Movement - uncontrollable

    MedlinePlus

    ... peripheral nervous system References Jankovic J, Lang AE. Movement disorders: diagnosis and assessment. In: Daroff RB, Fenichel GM, ... Elsevier Saunders; 2012:chap 21. Lang AE. Other movement disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  15. Surveying and Geophysical Measurements with Inertial Rotation Sensors

    DTIC Science & Technology

    1978-01-01

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

  16. A Development of the astronomical teaching materials which raise a student's time and and space concept by using of movement of the Moon, the Earth and the Sun

    NASA Astrophysics Data System (ADS)

    Taketa, I.; Matsumoto, I.

    2013-12-01

    In recent years, such as a return of the asteroid probe in 2010 "Hayabusa", a gold ring solar eclipse in 2012, and solar Face passage of Venus in 2012, there were many astronomical phenomena which pull a not only child but also citizen's interest, and they were greatly reported by the media in Japan. Thus, it is thought that the interest and concern about the universe of a child and a citizen are increasing. However, the earth science contents of a subject, such as the universe in school education are fields that it make comparatively poor at a teacher. So, this research aimed at the Development of the new space education teaching material which is easy to treat the teacher who has consciousness weak to the astronomical field at schools, and raise a child's time and space concepts. We did this research using the following Methods. 1) We carried out the questionnaire to the primary teacher of the Matsue city, and performed the opinion poll to a teacher's astronomical field. 2) We considered the subject on the education of the astronomical teaching materials used now. 3) As mentioned above 1) and 2), We developed the teaching materials which the waxing and waning of the moon based on the acquired content.

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

    NASA Astrophysics Data System (ADS)

    Hayashi, K.

    2014-12-01

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

  18. 1994 Geophysical images contest entries sought

    NASA Astrophysics Data System (ADS)

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

  19. A New Social Contract for Geophysics

    NASA Astrophysics Data System (ADS)

    Malone, T. F.

    2002-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  1. Constrained optimization schemes for geophysical inversion of seismic data

    NASA Astrophysics Data System (ADS)

    Sosa Aguirre, Uram Anibal

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

  2. A substantiation of cyclic process of the system Earth-Moon-Sun tidal evolution

    NASA Astrophysics Data System (ADS)

    Avsyuk, Y.

    2007-12-01

    The present-day knowledge of the Earth and thorough description of the tidal force affecting the system Earth-Moon-Sun permits us to work out in detail a tidal evolution model. Thus we get a possibility to reconstruct global variations of the climate. The tidal evolution of natural processes on the Earth that has a huge satellite (the Moon mass is only 81 times less than the Earth mass) essentially differs from the evolution on a planet that has no satellite. There are some natural processes that are well-known in astrometry and geophysics but disregarded by experts in geodynamics and geotectonics. The movement of the rotation axis in the Earth's body is discovered more a century ago, but there is no a model explaining the mechanism of this process. Our predecessors emphasized importance of the discovery and suggested desire of such a model. G.H.Darwin in his comments on "Z-term" in the latitude variation wrote this movement could be due to alternate displacement of the Earth center. To explain the scale of that phenomena it is enough to adopt a displacement of the Earth center by twelve feet. A question is to the point is whether the Earth axis movement concerns with the Inner core (IC) displacements. There are some reasons testifying to forced movements of the IC. To understand the forcing influence one must not simplify the Earth's real orbital movement. In fact the system Earth-Moon rotates around the Sun with the period of year. The ecliptic is a plane containing the orbit of the Earth and the Moon mass center (barycenter). The Sun attraction is balanced dynamically in the barycenter but not in the Earth center. As a result, the Earth rotates just as the Moon round the barycenter with the period of the Moon month, and therefore the IC is subjected to a variable tidal force (1910). Newton in Append. XXV, problem VI, underlined that inasmuch as the Earth and the Moon rotate round their common mass center, the Earth movement is disturbed with similar forces

  3. The Expanding Marketplace for Applied Geophysics

    NASA Astrophysics Data System (ADS)

    Carlson, N.; Sirles, P.

    2012-12-01

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

  4. Geophysical weight loss diet

    NASA Astrophysics Data System (ADS)

    Schatten, Kenneth

    1984-04-01

    Having for numerous reasons acquired a three digit kilogram mass, the author is experienced at the painful struggles that the gourmand must suffer to reduce weight, particularly if he/she enjoys reasonably large amounts of good food. To the avant-garde geophysicist, utilizing the following approach could be pleasurable, rewarding, and may even enable the accomplishment of what Ghengis Khan, Alexander the Great, Napolean, and Hitler could not!The basic approach is the full utilization of Newton's formula for the attraction of two massive bodies: F=GM1M2/r2, where G, is the gravitational constant; r, the distance between the two bodies; and M1 and M2, the masses of the two bodies. Although one usually chooses M1 to be the earth's mass ME and M2 to be the mass of a small object, this unnecessarily restricts the realm of phenomena. The less restrictive assumption is M1 + M2 = ME.

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

    USGS Publications Warehouse

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

    1982-01-01

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

  6. Geophysical subsurface imaging and interface identification.

    SciTech Connect

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

    2005-09-01

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

  7. Sulfur Earth

    NASA Astrophysics Data System (ADS)

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  8. Object Storage for Geophysical Data

    NASA Astrophysics Data System (ADS)

    Habermann, T.; Readey, J.

    2015-12-01

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

  9. Geophysics Fatally Flawed by False Fundamental Philosophy

    NASA Astrophysics Data System (ADS)

    Myers, L. S.

    2004-05-01

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

  10. News and Views: CSR: the devil will be in the detail; MPs invite researchers to show off success; Earthquake movies reveal ground movements

    NASA Astrophysics Data System (ADS)

    2010-12-01

    The UK Government's Comprehensive Spending Review set out a distinctly tighter budget all round in October, but science funding as a whole was not as badly cut as some had feared. What this means for astronomy, planetary science and geophysics remains to be seen, as individual research council allocations have yet to be agreed. Early-career researchers with results to shout about have the opportunity to display and discuss their work at the House of Commons next year, as part of the SET for Britain event on 14 March. Seismology took a great step forward when international cooperation at the time of International Geophysical Year 1957/8 meant that earth movements resulting from quakes could be compared worldwide.

  11. Precession, Nutation and Wobble of the Earth

    NASA Astrophysics Data System (ADS)

    Dehant, V.; Mathews, P. M.

    2015-04-01

    Covering both astronomical and geophysical perspectives, this book describes changes in the Earth's orientation, specifically precession and nutation, and how they are observed and computed in terms of tidal forcing and models of the Earth's interior. Following an introduction to key concepts and elementary geodetic theory, the book describes how precise measurements of the Earth's orientation are made using observations of extra-galactic radio-sources by Very Long Baseline Interferometry techniques. It demonstrates how models are used to accurately pinpoint the location and orientation of the Earth with reference to the stars and how to determine variations in its rotation speed. A theoretical framework is also presented that describes the role played by the structure and properties of the Earth's deep interior. Incorporating suggestions for future developments in nutation theory for the next generation models, this book is ideal for advanced-level students and researche! rs in solid Earth geophysics, planetary science and astronomy.

  12. A Unified Global Reference Frame of Vertical Crustal Movements by Satellite Laser Ranging.

    PubMed

    Zhu, Xinhui; Wang, Ren; Sun, Fuping; Wang, Jinling

    2016-02-08

    Crustal movement is one of the main factors influencing the change of the Earth system, especially in its vertical direction, which affects people's daily life through the frequent occurrence of earthquakes, geological disasters, and so on. In order to get a better study and application of the vertical crustal movement,as well as its changes, the foundation and prerequisite areto devise and establish its reference frame; especially, a unified global reference frame is required. Since SLR (satellite laser ranging) is one of the most accurate space techniques for monitoring geocentric motion and can directly measure the ground station's geocentric coordinates and velocities relative to the centre of the Earth's mass, we proposed to take the vertical velocity of the SLR technique in the ITRF2008 framework as the reference frame of vertical crustal motion, which we defined as the SLR vertical reference frame (SVRF). The systematic bias between other velocity fields and the SVRF was resolved by using the GPS (Global Positioning System) and VLBI (very long baseline interferometry) velocity observations, and the unity of other velocity fields and SVRF was realized,as well. The results show that it is feasible and suitable to take the SVRF as a reference frame, which has both geophysical meanings and geodetic observations, so we recommend taking the SLR vertical velocity under ITRF2008 as the global reference frame of vertical crustal movement.

  13. Studies of earth simulation experiments

    NASA Technical Reports Server (NTRS)

    Hart, J. E.

    1976-01-01

    The low gravity environment of earth orbit offers the potential for performing experiments involving baroclinic Geophysical Fluid Dynamics (GFD) on spherical surfaces. These experiments in turn have the potential for providing deeper understanding of large scale planetary and solar circulations. However, to perform these experiments, one requires an experimental technique whereby a radially directed body force can be generated to simulate a radial gravitational force field. One viable technique is the use of dielectric fluids with temperature dependent dielectric permittivity in a radially directed electric field. Application of the Boussinesq approximation to the equations of motion for this system and restrictions on the size of certain electrodynamic terms in the energy equations yields a set of equations which are analogous to the equations of motions of geophysical systems like the earth's atmosphere on term by term basis. The theoretical design of GFD experiments for performance in earth orbit are described along with results of preliminary tests of a prototype.

  14. [Stereotypic movements].

    PubMed

    Fernández-Alvarez, E

    2003-02-01

    Stereotypic movements are repetitive patterns of movement with certain peculiar features that make them especially interesting. Their physiopathology and their relationship with the neurobehavioural disorders they are frequently associated with are unknown. In this paper our aim is to offer a simple analysis of their dominant characteristics, their differentiation from other processes and a hypothesis of the properties of stereotypic movements, which could all set the foundations for research work into their physiopathology.

  15. 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.

  16. The Global Geophysical Fluids Center of IERS (and its Special Bureau for Mantle)

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2002-01-01

    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 also maintain individual website for data services and information exchanges. See URL . 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.

  17. Earth Sciences annual report, 1987

    SciTech Connect

    Younker, L.W.; Donohue, M.L.; Peterson, S.J.

    1988-12-01

    The Earth Sciences Department at Lawrence Livermore National Laboratory conducts work in support of the Laboratory's energy, defense, and research programs. The Department is organized into ten groups. Five of these -- Nuclear Waste Management, Fossil Energy, Containment, Verification, and Research -- represent major programmatic activities within the Department. Five others -- Experimental Geophysics, Geomechanics, Geology/Geological Engineering, Geochemistry, and Seismology/Applied Geophysics -- are major disciplinary areas that support these and other laboratory programs. This report summarizes work carried out in 1987 by each group and contains a bibliography of their 1987 publications.

  18. Contemporary geophysics from Babylonian clay tablets

    NASA Astrophysics Data System (ADS)

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

    1997-01-01

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

  19. Satellite gravity gradient grids for geophysics.

    PubMed

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

    2016-02-11

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

  20. Radar interferometry and its application to changes in the Earth's surface

    NASA Astrophysics Data System (ADS)

    Massonnet, Didier; Feigl, Kurt L.

    1998-11-01

    Geophysical applications of radar interferometry to measure changes in the Earth's surface have exploded in the early 1990s. This new geodetic technique calculates the interference pattern caused by the difference in phase between two images acquired by a spaceborne synthetic aperture radar at two distinct times. The resulting interferogram is a contour map of the change in distance between the ground and the radar instrument. These maps provide an unsurpassed spatial sampling density (˜100 pixels km-2), a competitive precision (˜1 cm), and a useful observation cadence (1 pass month-1). They record movements in the crust, perturbations in the atmosphere, dielectric modifications in the soil, and relief in the topography. They are also sensitive to technical effects, such as relative variations in the radar's trajectory or variations in its frequency standard. We describe how all these phenomena contribute to an interferogram. Then a practical summary explains the techniques for calculating and manipulating interferograms from various radar instruments, including the four satellites currently in orbit: ERS-1, ERS-2, JERS-1, and RADARSAT. The next chapter suggests some guidelines for interpreting an interferogram as a geophysical measurement: respecting the limits of the technique, assessing its uncertainty, recognizing artifacts, and discriminating different types of signal. We then review the geophysical applications published to date, most of which study deformation related to earthquakes, volcanoes, and glaciers using ERS-1 data. We also show examples of monitoring natural hazards and environmental alterations related to landslides, subsidence, and agriculture. In addition, we consider subtler geophysical signals such as postseismic relaxation, tidal loading of coastal areas, and interseismic strain accumulation. We conclude with our perspectives on the future of radar interferometry. The objective of the review is for the reader to develop the physical

  1. 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

  2. A survey of the theory of the Earth's rotation

    NASA Technical Reports Server (NTRS)

    Cannon, W. H.

    1981-01-01

    The theory of the Earth's rotation and the geophysical phenomena affecting it is examined. First principles are reviewed and the problem of polar motion and UT1 variations is formulated in considerable generality and detail. The effects of Earth deformations and the solid Earth tides are analyzed.

  3. Geophysical applications of satellite altimetry

    SciTech Connect

    Sandwell, D.T. )

    1991-01-01

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

  4. BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.

    USGS Publications Warehouse

    Seeley, Robert L.; Daniels, Jeffrey J.

    1984-01-01

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

  5. The Geophysical Revolution in Geology.

    ERIC Educational Resources Information Center

    Smith, Peter J.

    1980-01-01

    Discussed is the physicists' impact on the revolution in the earth sciences particularly involving the overthrow of the fixist notions in geology. Topics discussed include the mobile earth, the route to plate tectonics, radiometric dating, the earth's magnetic field, ocean floor spreading plate boundaries, infiltration of physics into geology and…

  6. Forward modeling of geophysical electromagnetic methods using Comsol

    NASA Astrophysics Data System (ADS)

    Butler, S. L.; Zhang, Z.

    2016-02-01

    In geophysical electromagnetic methods, time-varying magnetic fields are measured at Earth's surface that are produced by electrical currents inside the Earth in order to constrain subsurface conductivity and geological structure. These methods are widely used for mineral exploration and environmental investigations, and are increasingly being used in hydrocarbon exploration as well. Forward modeling of exploration geophysics methods is useful for the purpose of survey planning, for understanding the method, especially for students, and as part of an iteration process in inverting measured data. Modeling electromagnetic methods remains an area of active research. In most geophysical methods, the electromagnetic frequency is sufficiently low that the wavelength of the radiation is much larger than the area of interest. As such, the quasi-static approximation is valid. Comsol Multiphysics' AC/DC module solves Maxwell's equations in the quasi-static approximation and in this contribution, we will show examples of its use in modeling magnetometric resistivity (MMR), very low frequency (VLF) techniques, as well as frequency and time-domain induction-based electromagnetic techniques. Solutions are compared with benchmarks from the literature.

  7. Earth Sciences Division annual report 1981. [Lead abstract

    SciTech Connect

    Not Available

    1982-09-01

    Separate abstracts were prepared for the 59 papers of the 1981 annual report of the Earth Sciences Division at Lawrence Berkeley Laboratory. The general topics covered included nuclear waste isolation, geophysics and reservoir engineering, and geosciences. (KRM)

  8. Satellite-tracking and earth-dynamics research programs

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The activities and progress in the satellite tracking and earth dynamics research during the first half of calendar year 1975 are described. Satellite tracking network operations, satellite geodesy and geophysics programs, GEOS 3 project support, and atmospheric research are covered.

  9. Chloroplast movement.

    PubMed

    Wada, Masamitsu; Kagawa, Takatoshi; Sato, Yoshikatsu

    2003-01-01

    The study of chloroplast movement made a quantum leap at the beginning of the twenty-first century. Research based on reverse-genetic approaches using targeted mutants has brought new concepts to this field. One of the most exciting findings has been the discovery of photoreceptors for both accumulation and avoidance responses in Arabidopsis and in the fern Adiantum. Evidence for the adaptive advantage of chloroplast avoidance movements in plant survival has also been found. Additional discoveries include mechano-stress-induced chloroplast movement in ferns and mosses, and microtubule-mediated chloroplast movement in the moss Physcomitrella. The possible ecological significance of chloroplast movement is discussed in the final part of this review.

  10. Multidisciplinary Geophysical Study of the Earth’s Upper Structure.

    DTIC Science & Technology

    1988-12-27

    Tectonic Framework of southern New England and eastern New York, in. Kay, M., ed.. North Atlantic Geology and Continental Drift: American...reflection lines in the onshore and offshore portions of New England; and (3) by analysis of the geology of the region in the light of data from our...magnetic observatory installations and VLF meter, and analysis of existing aeromagnetic maps, suggest that major fault zones in eastern MA

  11. Decadal variations in geophysical processes and asymmetries in the solar motion about the Solar System's barycentre

    NASA Astrophysics Data System (ADS)

    Sidorenkov, Nikolay; Wilson, Ian; Khlystov, Anatoly

    2010-05-01

    transferred to the Sun, and then back from it to all of the other planets. In other words, the Sun acts as a re-transmitter of gravitational motion over all of the solar system. 2) Activization of similar physical processes should take place simultaneously on all bodies in the solar system. Support for the last conclusion comes from the investigation of link between the most severe droughts on the Earth and powerful dust storms on Mars (Khlystov, 1995). Ian Wilson et al. (2008) presented evidence that claimed that changes in the Sun's equatorial rotation rate are synchronized with changes in the Sun's orbital motion about the barycentre of the Solar System. This paper showed that the recent maximum asymmetries in the Solar motion about the barycentre have occurred in the years 1865, 1900, 1934, 1970 and 2007. These years closely match the points of inflection in the Earth's LOD. In addition, Ian Wilson (Sidorenkov and Wilson 2009) shows that, from 1700 to 2000 A.D., on every occasion where the Sun has experienced a maximum in the asymmetry of its motion about the centre-of-mass of the Solar System, the Earth has also experienced a significant deviation in its rotation rate (i.e. LOD) from that expected from the long-term trends. This fact indicates that the changes in the Earth's rotation rate are synchronized with a phenomenon that is linked to the changes in the solar motion about the barycentre of the Solar System. Thus from the empirical data, we argue that there is compelling evidence to support the idea that these correlations are due to the shared motion of the Sun and Earth about the barycentre of the Solar System. We show that asymmetries in this shared motion lead to the decadal fluctuations in the climatologically and geophysical processes, including long term changes in the Earth's rotation rate. REFERENCES 1. Khlystov A.I., V.P.Dolgachev, and L.M.Domozhilova (1992). Barycentric movement of the Sun and Solar-Terrestrial relations, Biophysics, vol. 37, No 3, 455

  12. Geophysical Institute. Biennial report, 1993-1994

    SciTech Connect

    1996-01-01

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

  13. The Emergence of Geophysics in Nineteenth Century Britain.

    NASA Astrophysics Data System (ADS)

    Kushner, David S.

    1990-01-01

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

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

    USGS Publications Warehouse

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

    2006-01-01

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

  15. Alternative experiments using the geophysical fluid flow cell

    NASA Technical Reports Server (NTRS)

    Hart, J. E.

    1984-01-01

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

  16. A review of integrated geophysical investigations from archaeological and cultural sites under encroaching urbanisation in İzmir, Turkey

    NASA Astrophysics Data System (ADS)

    Drahor, Mahmut Göktuğ

    In the new millennium, globalisation, and with it urbanisation, has been expanding as a consequence of economic development throughout the world. Urbanisation is a major social problem, not only for developing countries but also for developed countries. Urbanisation also has a major impact on archaeological sites and cultural heritages in urbanised zones. Non-destructive investigation techniques, such as geophysics, which uses remote sensing, and is non-invasive, are of great importance in urban areas. We are now capable of solving urbanisation-related problems, and these techniques reduce the cost of projects at urbanised sites. Geophysics has increased the possibilities of new applications in determining intensive urbanisation effects in earth science. Geophysics deals with numerous physical variations such as electricity, electromagnetism, magnetics, acoustics, gravity and radioactivity. There are numerous ways geophysics can be applied in archaeological and cultural heritage studies. In addition the hazard mitigation, infrastructure investigation, waste management, water supply, urban gateways and other factors are documented by geophysics. In recent years, archaeological sites under the encroachment of urbanisation have been investigated on numerous occasions using non-invasive geophysical techniques, allowing parameters such as the depth, dimension and extension of targets to be clearly determined. The term “urban geophysics” has recently been seen in various references related to geophysics and other earth science studies. This study reviews the results of geophysical investigations carried out at important archaeological sites under encroaching urbanisation in the city of İzmir, Turkey.

  17. Polar Misunderstandings: Earth's Dynamic Dynamo

    ERIC Educational Resources Information Center

    DiSpezio, Michael A.

    2011-01-01

    This article discusses the movement of Earth's north and south poles. The Earth's poles may be a bit more complex and dynamic than what many students and teachers believe. With better understanding, offer them up as a rich landscape for higher-level critical analysis and subject integration. Possible curriculum tie-ins include magnets, Earth…

  18. Geophysical fields of a megalopolis

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  19. New Geophysical Observatory in Uruguay

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  20. Smith heads Reviews of Geophysics

    NASA Astrophysics Data System (ADS)

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

  1. Use of natural gamma-ray geophysical logs for SWAT water table parameter estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preliminary soil and sub-soil hydraulic parameter estimates needed for SWAT simulations to determine sub-surface water movement were collected using downhole geophysical measurements. Gamma-ray logs are useful for distingishing sandstone from shales by measuring natural-gamma radiation emitted from ...

  2. Movement - uncoordinated

    MedlinePlus

    Lack of coordination; Loss of coordination; Coordination impairment; Ataxia; Clumsiness; Uncoordinated movement ... are passed through families (such as congenital cerebellar ataxia, Friedreich ataxia , ataxia - telangiectasia , or Wilson disease ) Multiple ...

  3. Geophysical Fluid Flow Cell Simulation

    NASA Technical Reports Server (NTRS)

    1998-01-01

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

  4. 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.

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

    USGS Publications Warehouse

    Drenth, Benjamin J.

    2011-01-01

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

  6. 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

  7. Geophysical Model Research and Results

    SciTech Connect

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

    2004-07-07

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

  8. The Earth System Model

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark; Rood, Richard B.; Hildebrand, Peter; Raymond, Carol

    2003-01-01

    The Earth System Model is the natural evolution of current climate models and will be the ultimate embodiment of our geophysical understanding of the planet. These models are constructed from components - atmosphere, ocean, ice, land, chemistry, solid earth, etc. models and merged together through a coupling program which is responsible for the exchange of data from the components. Climate models and future earth system models will have standardized modules, and these standards are now being developed by the ESMF project funded by NASA. The Earth System Model will have a variety of uses beyond climate prediction. The model can be used to build climate data records making it the core of an assimilation system, and it can be used in OSSE experiments to evaluate. The computing and storage requirements for the ESM appear to be daunting. However, the Japanese ES theoretical computing capability is already within 20% of the minimum requirements needed for some 2010 climate model applications. Thus it seems very possible that a focused effort to build an Earth System Model will achieve succcss.

  9. ``An Earth-Shaking Experience''

    NASA Astrophysics Data System (ADS)

    Achenbach, Joel

    2005-03-01

    Last month's annual meeting of the American Geophysical Union in San Francisco drew an estimated 11,000 scientists, teachers, journalists and geophysics groupies. The schedule of talks could be found in a bound volume as thick as a phone book. You never see a geophysicist in ordinary life, but apparently the world is crawling with them. They came to talk about everything from the ozone layer to the big wad of iron at the center of the Earth. Also about other planets. And magnetic fields. Solar wind. Water on Mars. To be at this convention was to be immersed to the eyebrows in scientific knowledge. It is intellectually fashionable to fetishize the unknown, but at AGU, a person will get the opposite feeling-that science is a voracious, relentless and tireless enterprise, and that soon there may not remain on this Earth an unturned stone.

  10. Earth's core iron

    NASA Astrophysics Data System (ADS)

    Geophysicist J. Michael Brown of Texas A & M University noted recently at the Spring AGU Meeting in Baltimore that the structure and phase of metallic iron at pressures of the earth's inner core (approximately 3.3 Mbar) could have great significance in defining geometrical aspects of the core itself. Brown worked at the Los Alamos Scientific Laboratory with R.B. McQueen to redetermine the phase relations of metallic iron in a series of new shock-wave experiments. They found the melting point of iron at conditions equal to those at the boundary of the earth's outer (liquid) and inner (solid) cores to be 6000°±500°C (Geophysical Research Letters, 7, 533-536, 1980).

  11. Geophysical tomography. January 1976-July 1988 (Citations from the NTIS data base). Report for January 1976-July 1988

    SciTech Connect

    Not Available

    1988-07-01

    This bibliography contains citations concerning image reconstruction of geologic properties, internal geometry of rock masses, and mapping of fractures using geophysical tomography. Applications include site characterization, ground-water movement, structural geology, well logging, oil-field recovery processes, underground waste disposal, and geophysical surveys. The citations on techniques include algorithms and software to perform tomographic image reconstruction. (Contains 74 citations fully indexed and including a title list.)

  12. Early Earth

    NASA Astrophysics Data System (ADS)

    Brown, M.

    2015-05-01

    Earth has continents, subduction and mobile lid plate tectonics, but details of the early evolution are poorly understood. Here I summarize the Hadean-Archean record, review evidence for a hotter Earth and consider geodynamic models for early Earth.

  13. Magnetotellurics as a multiscale geophysical exploration method

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  14. Satellite gravity gradient grids for geophysics

    PubMed Central

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

    2016-01-01

    The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite aimed at determining the Earth’s mean gravity field. GOCE delivered gravity gradients containing directional information, which are complicated to use because of their error characteristics and because they are given in a rotating instrument frame indirectly related to the Earth. We compute gravity gradients in grids at 225 km and 255 km altitude above the reference ellipsoid corresponding to the GOCE nominal and lower orbit phases respectively, and find that the grids may contain additional high-frequency content compared with GOCE-based global models. We discuss the gradient sensitivity for crustal depth slices using a 3D lithospheric model of the North-East Atlantic region, which shows that the depth sensitivity differs from gradient to gradient. In addition, the relative signal power for the individual gradient component changes comparing the 225 km and 255 km grids, implying that using all components at different heights reduces parameter uncertainties in geophysical modelling. Furthermore, since gravity gradients contain complementary information to gravity, we foresee the use of the grids in a wide range of applications from lithospheric modelling to studies on dynamic topography, and glacial isostatic adjustment, to bedrock geometry determination under ice sheets. PMID:26864314

  15. Earth's motions in pharaonic Egypt: Religious interpretations

    NASA Astrophysics Data System (ADS)

    Jambon, Emmanuel

    This paper will deal with the representations of the earth's movements in pharaonic Egypt. At first, testimonies of an ancient literary pattern, the "sky and earth" figure, will be observed, and then, the pictures where earth is represented "alone". We will explore the different ways the Egyptians depicted and interpreted this phenomena through various texts.

  16. Geophysical Model Applications for Monitoring

    SciTech Connect

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

    2005-07-11

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

  17. Earth Rotation Dynamics: Review and Prospects

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

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

  18. Bringing 3D Printing to Geophysical Science Education

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    SciTech Connect

    Jeffrey G. Paine

    2009-03-13

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

  20. Lunar geophysics, geodesy, and dynamics

    NASA Technical Reports Server (NTRS)

    Williams, J. G.; Dickey, J. O.

    2002-01-01

    Experience with the dynamics and data analyses for earth and moon reveals both similarities and differences. Analysis of Lunar Laser Ranging (LLR) data provides information on the lunar orbit, rotation, solid-body tides, and retroreflector locations.

  1. Application of borehole geophysics to fracture identification and characterization in low porosity limestones and dolostones

    SciTech Connect

    Haase, C.S.; King, H.L.

    1986-01-01

    Geophysical logging was conducted in exploratory core holes drilled for geohydrological investigations at three sites used for waste disposal on the US Department of Energy's Oak Ridge Reservation. Geophysical log response was calibrated to borehole geology using the drill core. Subsequently, the logs were used to identify fractures and fractured zones and to characterize the hydrologic activity of such zones. Results of the study were used to identify zones of ground water movement and to select targets for subsequent piezometer and monitoring well installation. Neutron porosity, long- and short-normal resistivity, and density logs exhibit anomalies only adjacent to pervasively fractured zones and rarely exhibit anomalies adjacent to individual fractures, suggesting that such logs have insufficient resolution to detect individual fractures. Spontaneous potential, single point resistance, acoustic velocity, and acoustic variable density logs, however, typically exhibit anomalies adjacent to both individual fractures and fracture zones. Correlation is excellent between fracture density logs prepared from the examination of drill core and fractures identified by the analysis of a suite of geophysical logs that have differing spatial resolution characteristics. Results of the study demonstrate the importance of (1) calibrating geophysical log response to drill core from a site, and (2) running a comprehensive suite of geophysical logs that can evaluate both large- and small-scale rock features. Once geophysical log responses to site-specific geological features have been established, logs provide a means of identifying fracture zones and discriminating between hydrologically active and inactive fracture zones. 9 figs.

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

    USGS Publications Warehouse

    Shah, Anjana K.

    2016-01-01

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

  3. Earth Sciences Division annual report 1989

    SciTech Connect

    Not Available

    1990-06-01

    This Annual Report presents summaries of selected representative research activities from Lawrence Berkeley Laboratory grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrology, Geology and Geochemistry, and Geophysics and Geomechanics. We are proud to be able to bring you this report, which we hope will convey not only a description of the Division's scientific activities but also a sense of the enthusiasm and excitement present today in the Earth Sciences.

  4. Chloroplast movement.

    PubMed

    Wada, Masamitsu

    2013-09-01

    Chloroplast movement is important for plant survival under high light and for efficient photosynthesis under low light. This review introduces recent knowledge on chloroplast movement and shows how to analyze the responses and the moving mechanisms, potentially inspiring research in this field. Avoidance from the strong light is mediated by blue light receptor phototropin 2 (phot2) plausibly localized on the chloroplast envelop and accumulation at the week light-irradiated area is mediated by phot1 and phot2 localized on the plasma membrane. Chloroplasts move by chloroplast actin (cp-actin) filaments that must be polymerized by Chloroplast Unusual Positioning1 (CHUP1) at the front side of moving chloroplast. To understand the signal transduction pathways and the mechanism of chloroplast movement, that is, from light capture to motive force-generating mechanism, various methods should be employed based on the various aspects. Observation of chloroplast distribution pattern under different light condition by fixed cell sectioning is somewhat an old-fashioned technique but the most basic and important way. However, most importantly, precise chloroplast behavior during and just after the induction of chloroplast movement by partial cell irradiation using an irradiator with either low light or strong light microbeam should be recorded by time lapse photographs under infrared light and analyzed. Recently various factors involved in chloroplast movement, such as cp-actin filaments and CHUP1, could be traced in Arabidopsis transgenic lines with fluorescent protein tags under a confocal laser scanning microscope (CLSM) and/or a total internal reflection fluorescence microscope (TIRFM). These methods are listed and their advantages and disadvantages are evaluated.

  5. SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT

    SciTech Connect

    RUCKER DF; MYERS DA

    2011-10-04

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

  6. A Unified Global Reference Frame of Vertical Crustal Movements by Satellite Laser Ranging

    PubMed Central

    Zhu, Xinhui; Wang, Ren; Sun, Fuping; Wang, Jinling

    2016-01-01

    Crustal movement is one of the main factors influencing the change of the Earth system, especially in its vertical direction, which affects people’s daily life through the frequent occurrence of earthquakes, geological disasters, and so on. In order to get a better study and application of the vertical crustal movement, as well as its changes, the foundation and prerequisite areto devise and establish its reference frame; especially, a unified global reference frame is required. Since SLR (satellite laser ranging) is one of the most accurate space techniques for monitoring geocentric motion and can directly measure the ground station’s geocentric coordinates and velocities relative to the centre of the Earth’s mass, we proposed to take the vertical velocity of the SLR technique in the ITRF2008 framework as the reference frame of vertical crustal motion, which we defined as the SLR vertical reference frame (SVRF). The systematic bias between other velocity fields and the SVRF was resolved by using the GPS (Global Positioning System) and VLBI (very long baseline interferometry) velocity observations, and the unity of other velocity fields and SVRF was realized, as well. The results show that it is feasible and suitable to take the SVRF as a reference frame, which has both geophysical meanings and geodetic observations, so we recommend taking the SLR vertical velocity under ITRF2008 as the global reference frame of vertical crustal movement. PMID:26867197

  7. The measurement of Earth rotation on a deformable Earth

    NASA Technical Reports Server (NTRS)

    Cannon, W. H.

    1980-01-01

    Until recently, the methods of geodetic positioning on the Earth were limited to a precision of roughly one part in 10 to the 6th power. At this level of precision, the Earth can be regarded as a rigid body since the largest departure of the Earth from rigidity is manifested in the strains of the Earth tides which are of the order of one part in 10 to the 7th power. Long baseline interferometry is expected to routinely provide global positioning to a precision of one part in 10 to the 8th power or better. At this level of precision, all parts of the Earth's surface must be regarded as being, at least potentially, in continual motion relative to the geocenter as a result of a variety of geophysical effects. The general implications of this phenomenon for the theory of the Earth's rotation is discussed. Particular attention is given to the question of the measurement of the 'Earth's rotation vector' on a deformable Earth.

  8. A tool for Exploring Geophysical Data: The VGEE-IDV

    NASA Astrophysics Data System (ADS)

    Pandya, R. E.; Murray, D.

    2002-12-01

    heart of the VGEE is the visualization environment. The visualization environment is a customized version of the Integrated Data Viewer, or IDV, a platform-independent software package being developed by Unidata for display and analysis of geophysical data. In addition to the learner-centered functionality mentioned above, this environment allows the ability to locate and analyze remote data sets, including both archived and real-time data. As such, the tool represents a road toward creating a "data web" where educational users can browse and use data in a seamless way. While our discussion of the VGEE will highlight its use in specific curricula; we will point towards the development of the next generation data web in the Digital Library for Earth Science Education (DLESE). Our discussion will also summarize the data gathered while using the VGEE in an entry-level geoscience laboratory course.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

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

    NASA Astrophysics Data System (ADS)

    Leifert, Harvey

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

  11. Developing geophysical monitoring at Mayon volcano, a collaborative project EOS-PHIVOLCS

    NASA Astrophysics Data System (ADS)

    Hidayat, D.; Laguerta, E.; Baloloy, A.; Valerio, R.; Marcial, S. S.

    2011-12-01

    Mayon is an openly-degassed volcano, producing mostly small, frequent eruptions, most recently in Aug-Sept 2006 and Dec 2009. Mayon volcano status is level 1 with low seismicity dominated mostly local and regional tectonic earthquakes with continuous emission of SO2 from its crater. A research collaboration between Earth Observatory of Singapore-NTU and Philippine Institute of Volcanology and Seismology (PHIVOLCS) have been initiated in 2010 with effort to develop a multi-disciplinary monitoring system around Mayon includes geophysical monitoring, gas geochemical monitoring, and petrologic studies. Currently there are 4 broadband seismographs, 3 short period instruments, and 4 tiltmeters. These instruments will be telemetered to the Lignon Hill Volcano Observatory through radio and 3G broadband internet. We also make use of our self-made low-cost datalogger which has been operating since Jan 2011, performing continuous data acquisition with sampling rate of 20 minute/sample and transmitted through gsm network. First target of this monitoring system is to obtain continuous multi parameter data transmitted in real time to the observatory from different instruments. Tectonically, Mayon is located in the Oas Graben, a northwest-trending structural depression. Previous study using InSAR data, showing evidence of a left-lateral oblique slip movement of the fault North of Mayon. Understanding on what structures active deformation is occurring and how deformation signal is currently partitioned between tectonic and volcanic origin is a key for characterizing magma movement in the time of unrest. Preliminary analysis of the tangential components of tiltmeters (particularly the stations 5 and 7.5 NE from the volcano) shows gradual inflation movement over a few months period. The tangential components for tiltmeters are roughly perpendicular to the fault north of Mayon. This may suggest downward tilting of the graben in the northern side of Mayon. Another possibility is that

  12. Stovetop Earth Pecan Pie

    NASA Astrophysics Data System (ADS)

    Robin, C. M.

    2005-12-01

    Many fluid mechanical experiments with direct applications to Earth Science are performed with sugary syrups using conceptually straightforward procedures. Corn syrup has indeed proven to be a godsend for those studying convection and related non-linear phenomena. In addition, however, it gives experimentalists a deep physical intuition for the interior workings of hot planets. The basic concepts behind plate tectonics and mantle convection are not difficult; indeed, although they may not be aware of it, most students probably have a basic intuitive understanding of fluid mechanics gained in their daily life. However, the large size and long time scale of geophysical processes may be quite intimidating to young students. Even a simple geophysical experiment requires a complicated array of coolers, heaters and measuring and recording equipment. It is of interest to introduce students to the geodynamical concepts that can be visualized in a high-tech lab using familiar processes and equipment. Using a homemade apparatus and grocery store supplies, I propose using a 'Stove-top Earth pecan pie' to introduce simple geodynamic concepts to middle- and high-school students. The initially cold syrup heats up and the pecans begin to float (continent formation), the syrup begins to convect (mantle convection), and convection slows down after the heat is removed (secular cooling). Even Wilson cycles can be simulated by moving the pan to one side or the other of the stovetop or heating element. The activity formally introduces students to convection and its application to the earth, and makes them think about plate motion, heat transfer, scaling, and experimental procedures. As an added bonus, they can eat their experiments after recess!

  13. Remote sensing-a geophysical perspective.

    USGS Publications Warehouse

    Watson, K.

    1985-01-01

    In this review of developments in the field of remote sensing from a geophysical perspective, the subject is limited to the electromagnetic spectrum from 0.4 mu m to 25cm. Three broad energy categories are covered: solar reflected, thermal infrared, and microwave.-from Authorremote sensing electromagnetic spectrum solar reflected thermal infrared microwave geophysics

  14. Successful educational geophysics field program expands

    NASA Astrophysics Data System (ADS)

    The Summer of Applied Geophysical Experience (SAGE), a program that gives students an opportunity to apply a variety of modern geophysical methods in a challenging geologic environment, has expanded.A 2-year grant awarded in 1993 by the National Science Foundation's Research Experiences for Undergraduate's (REU) initiative allowed the program to include fourteen U.S. undergraduate students last summer.

  15. Agricultural Geophysics: Past, present, and future

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  16. Advances in borehole geophysics for hydrology

    SciTech Connect

    Nelson, P.H.

    1982-01-01

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

  17. Celebrating the physics in geophysics

    NASA Astrophysics Data System (ADS)

    Davis, Anthony B.; Sornette, Didier

    The United Nations' Educational, Scientific and Cultural Organization (UNESCO) declared 2005 the “World Year of Physics” in celebration of the centennial of Einstein's annus mirabilis when, as junior clerk at the Swiss Patent Office in Berne, he published three papers that changed physics forever by (1) introducing Special Relativity and demonstrating the equivalence of mass and energy (E = mc2), (2) explaining the photoelectric effect with Planck's then-still-new-and-controversial concept of light quanta (E = hv), and (3) investigating the macroscopic phenomenon of Brownian motion using Boltzmann's molecular dynamics (E = kT), still far from fully accepted at the time.The celebration of Einstein's work in physics inspires the reflection on the status of geophysics and its relationship with physics, in particular with respect to great discoveries.

  18. Goddard Geophysical and Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Figueroa, Ricardo

    2013-01-01

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

  19. Satellite Relaying of Geophysical Data

    NASA Technical Reports Server (NTRS)

    Allenby, R. J.

    1977-01-01

    Data Collection Platforms (DCPs) for transmitting surface data to an orbiting satellite for relaying to a central data distribution center are being used in a number of geophysical applications. "Off-the-shelf" DCP's, transmitting through Landsat or GOES satellites, are fully capable of relaying data from low-data-rate instruments, such as tiltmeters or tide gauges. In cooperation with the Lamont-Doherty Geological Observatory, Goddard has successfully installed DCP systems on a tide gauge and tiltmeter array on Anegada, British Virgin Islands. Because of the high-data-rate requirements, a practical relay system capable of handling seismic information is not yet available. Such a system could become the basis of an operational hazard prediction system for reducing losses due to major natural catastrophies such as earthquakes, volcanic eruptions, landslides or tsunamis.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    NASA Astrophysics Data System (ADS)

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

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

  2. Exploring Space, Exploring Earth: New Understanding of the Earth from Space Research

    NASA Astrophysics Data System (ADS)

    Lowman, Paul D., Jr.

    2002-08-01

    This book describes the impact of space flight on geology and geophysics, beginning with a foreword by Neil Armstrong, which illustrates how the exploration of space has lead us to a far deeper understanding of our own planet. Direct results from Earth-orbital missions include studies of Earth's gravity and magnetic fields. In contrast, the recognition of the economic and biological significance of impact craters on Earth is an indirect consequence of the study of the geology of other planets. The final chapter presents a new theory for the tectonic evolution of the Earth based on comparative planetology and the Gaia concept.

  3. Earth Resources

    ERIC Educational Resources Information Center

    Brewer, Tom

    1970-01-01

    Reviews some of the more concerted, large-scale efforts in the earth resources areas" in order to help the computer community obtain insights into the activities it can jointly particpate in withthe earth resources community." (Author)

  4. PreAnalyseExtended: A graphical tool for (geophysical) time series analysis

    NASA Astrophysics Data System (ADS)

    Gebauer, André

    2016-04-01

    Time depending records of different geophysical and geodetic measurement systems require screening and post-processing, often combining the primary observable with additional measurement quantities from other external sensors or geophysical models. The ring laser 'G' located at the Geodetic Observatory Wettzell for example observes rotational ground motions depending on the sensor orientation. Hence tilt effects need to be corrected from the raw measurements of rotation. While the local tilt is taken from an independent time series of an auxiliary sensor, solid Earth tides and polar motion are corrected based on appropriate models. PreAnalyseExtended is a powerful software tool that combines the screening and processing of geophysical measurements of a variety of input sensors with a unique set of at least seven fully included models. This talk provides an introduction the important features of this open source tool.

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

    USGS Publications Warehouse

    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.

  6. Faculty receives Excellence in Geophysical Education Award

    NASA Astrophysics Data System (ADS)

    Kruse, Sarah; Baldridge, W. Scott; Biehler, Shawn; Braile, Lawrence W.; Ferguson, John F.; Gilpin, Bernard E.; Jiracek, George R.

    “The second AGU Excellence in Geophysical Education Award was presented to the faculty of the Summer of Applied Geophysical Experience (SAGE): Scott Baldridge, Shawn Biehler, Larry Braile, John Ferguson, Bernard Gilpin, and George Jiracek. The persistence and commitment of this group has provided the geophysical community with a superb educational program for over 16 years, reaching nearly 400 students, including undergraduates, graduates, and professionals. The award was presented at the AGU Fall Meeting Honors Ceremony, which was held on December 8, 1998, in San Francisco, California.

  7. JGR-Solid Earth and Planets GP editor appointed

    NASA Astrophysics Data System (ADS)

    Ken Hoffman (Physics Department, California Polytechnic State University, San Luis Obispo) has been appointed GP editor for papers submitted to the Journal of Geophysical Research—Solid Earth and Planets. His tenure will be from January 1987 to December 1988. Hoffman holds a Ph.D. in geophysics from the University of California, Berkeley, and has published extensively in the areas of rock magnetism, paleomagnetism, lunar paleointensity, and most recently, geomagnetic dipole field reversal modeling.

  8. Earth Day Plus 20, and Counting.

    ERIC Educational Resources Information Center

    Gilbert, Bil

    1990-01-01

    Presents a historical perspective of the environmental movement in the United States, beginning with Earth Day, 1970. Profiles "environmentalists" and describes environmental activities, achievements with environmental reform, turning points, and proenvironmental legislation from 1970-90. (MCO)

  9. Clay-Motion: Modeling Our Dynamic Earth.

    ERIC Educational Resources Information Center

    Borrello, Murray C.

    1994-01-01

    Provides easy to teach and understand laboratory exercises for three fundamental concepts (plate movement, rock mechanics, and geologic time) that are often left out of the geology and Earth science curriculum. (ZWH)

  10. Geophysical aspects of remote sensing

    NASA Technical Reports Server (NTRS)

    Watson, K.

    1971-01-01

    Results obtained through the NASA Earth Resources Aircraft Program at Mill Creek, Oklahoma, provide a case history example of the application of remote sensing to the identification of geologic rock units. Thermal infrared images are interpreted by means of a sequence of models of increasing complexity. The roles of various parameters are examined: rock properties (thermal inertia, albedo, emissivity), site location (latitude), season (sun's declination), atmospheric effects (cloud cover, transmission, air temperature), and topographic orientation (slope, azimuth). The results obtained at this site also illustrate the development of an important application of remote sensing in geologic identification. Relatively pure limestones and dolomites of the Mill Creek test area can be differentiated in nighttime infrared images, and facies changes between them can be detected along and across strike. The predominance on the earth's surface of sedimentary rocks, of which limestone and dolomite are major members, indicates the importance of this discrimination.

  11. Feds fund geophysical energy research

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Amid the current confusion surrounding the pending fate of the United States Department of Energy (President Reagan proposed a plan to ‘dismantle’ it), a rather large program, sometimes called ‘Physical Research in the Geosciences,’ survives in financially healthy condition. According to the recent report ‘Summary Outline of DOE Geoscience and Geoscience-Related Research (DOE/ER-0120, Feb. 1982), the amount of funding granted to university researchers for the current fiscal year is $16 million.In a procedure similar to other federal government unsolicited grant research proplate grams, funds are awarded to successful university applicants on the basis of research proposals. An interesting note is that apparently because of the uncertainties surrounding the futures of several federal programs, including the DOE, some researchers have assumed, incorrectly, that many sources of research funding may be discontinued. Meanwhile, program directors of the National Science Foundation have told Eos that their programs are experiencing a large increase in research proposals because investigators are apparently seeking other sources of funding. As the Office of Management Budget request for fiscal year 1983 stands at the present time, funding for geophysical energy research will be increased substantially under the Office of Basic Energy Sciences.

  12. Geophysical Fluid Dynamics Outreach Films

    NASA Astrophysics Data System (ADS)

    Aurnou, J. M.; Schwarz, J. W.; Noguez, G.

    2012-12-01

    Here we will present high definition films of laboratory experiments demonstrating basic fluid motions similar to those occurring in atmospheres and oceans. In these experiments, we use water to simulate the fluid dynamics of both the liquid (oceans) and gaseous (atmospheric) envelopes. To simulate the spinning of the earth, we carry out the experiments on a rotating table. For each experiment, we begin by looking at our system first without the effects of rotation. Then, we include rotation to see how the behavior of the fluid changes due to the Coriolis accelerations. Our hope is that by viewing these experiments one will develop a sense for how fluids behave both in rotating and non-rotating systems. By noting the differences between the experiments, it should then be possible to establish a basis to think about large-scale fluid motions that exist in Earth's oceans and atmospheres as well as on planets other than Earth.Plan view image of vortices in a rotating tank of fluid. Movies of such flows make accessible the often difficult to comprehend fluid dynamical processes that occur in planetary atmospheres and oceans.

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

    NASA Astrophysics Data System (ADS)

    Aydemir, Attila

    2009-07-01

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

  14. The patient movement as an emancipation movement

    PubMed Central

    Williamson, Charlotte

    2008-01-01

    Abstract Objective  To suggest that the patient movement is an emancipation movement. Background  The patient movement is young and fragmented; and it can seem confusing because it lacks an explicit ideology with intellectual and theoretical underpinnings. Methods  Drawing mainly on the experiences and the published writings of patient activists, the author identified eight aspects of the patient movement that could be compared with aspects of recognized emancipation movements: the radicalization of activists; the creation of new knowledge; the identification of guiding principles; the sense of direction; the unmasking of new issues; schisms within the movement and allies outside it; and the gradual social acceptance of some of the ideas (here standards of health care) that activists work to promote. Results  Similarities between certain aspects of the patient movement and of the recognized emancipation movements were close. Conclusion  The patient movement can be regarded as an emancipation movement, albeit an immature one. PMID:18494955

  15. 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)

  16. 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)

  17. Discover Earth

    NASA Technical Reports Server (NTRS)

    Steele, Colleen

    1998-01-01

    Discover Earth is a NASA-sponsored project for teachers of grades 5-12, designed to: (1) enhance understanding of the Earth as an integrated system; (2) enhance the interdisciplinary approach to science instruction; and (3) provide classroom materials that focus on those goals. Discover Earth is conducted by the Institute for Global Environmental Strategies in collaboration with Dr. Eric Barron, Director, Earth System Science Center, The Pennsylvania State University; and Dr. Robert Hudson, Chair, the Department of Meteorology, University of Maryland at College Park. The enclosed materials: (1) represent only part of the Discover Earth materials; (2) were developed by classroom teachers who are participating in the Discover Earth project; (3) utilize an investigative approach and on-line data; and (4) can be effectively adjusted to classrooms with greater/without technology access. The Discover Earth classroom materials focus on the Earth system and key issues of global climate change including topics such as the greenhouse effect, clouds and Earth's radiation balance, surface hydrology and land cover, and volcanoes and climate change. All the materials developed to date are available on line at (http://www.strategies.org) You are encouraged to submit comments and recommendations about these materials to the Discover Earth project manager, contact information is listed below. You are welcome to duplicate all these materials.

  18. 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.

  19. Geophysical applications for levee assessment

    NASA Astrophysics Data System (ADS)

    Chlaib, Hussein Khalefa

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

  20. Studies in geophysics groundwater contamination by Geophysics Study Committee

    SciTech Connect

    Not Available

    1984-01-01

    The book cites the massive application of chemicals to the land and the possibility of groundwater contamination and the extent of contamination on the natural scale. Movement by microscopic and macroscopic processes is discussed together with a description of chemical processes involved. This is followed by description of shallow land disposal of municipal waste and deep well injection. Several specific examples are then described and discussed. For example, the section on the Love Canal discusses a modeling system and recommendations for receiving the problem. Each section includes an abstract and a comprehensive set of references. It is well written, comprehensive and a valuable addition to the library of anyone working on the environmental problems of groundwater contamination.

  1. Geophysical observations at cavity collapse

    NASA Astrophysics Data System (ADS)

    Jousset, Philippe; Bazargan-Sabet, Behrooz; Lebert, François; Bernardie, Séverine; Gourry, Jean-Christophe

    2010-05-01

    In Lorraine region (France) salt layers at about 200 meters depth are exploited by Solvay using solution mining methodology which consists in extracting the salt by dissolution, collapsing the cavern overburden during the exploitation phase and finally reclaiming the landscape by creating a water area. In this process, one of the main challenges for the exploiting company is to control the initial 120-m diameter collapse so as to minimize possible damages. In order to detect potential precursors and understand processes associated with such collapses, a wide series of monitoring techniques including micro seismics, broad-band seismology, hydro-acoustic, electromagnetism, gas probing, automatic leveling, continuous GPS, continuous gravity and borehole extensometry was set-up in the frame of an in-situ study carried out by the "Research Group for the Impact and Safety of Underground Works" (GISOS, France). Equipments were set-up well before the final collapse, giving a unique opportunity to analyze a great deal of information prior to and during the collapse process which has been successfully achieved on February the 13th, 2009 by controlling the cavity internal pressure. In this work, we present the results of data recorded by a network of 3 broadband seismometers, 2 accelerometers, 2 tilt-meters and a continuously gravity meter. We relate the variations of the brine pumping rate with the evolutions of the induced geophysical signals and finally we propose a first mechanical model for describing the controlled collapse. Beyond the studied case, extrapolation of the results obtained might contribute to the understanding of uncontrolled cavity collapses, such as pit-craters or calderas at volcanoes.

  2. Geophysics of Small Planetary Bodies

    NASA Technical Reports Server (NTRS)

    Asphaug, Erik I.

    1998-01-01

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

  3. 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.

  4. 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

  5. Contribution of Geophysical Prospecting to Geohazard Evaluation

    SciTech Connect

    Nicolich, Rinaldo

    2006-03-23

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

  6. Earth Science Information System (ESIS)

    USGS Publications Warehouse

    ,

    1982-01-01

    The Earth Science Information System (ESIS) was developed in 1981 by the U.S. Geological Survey's Office of the Data Administrator. ESIS serves as a comprehensive data management facility designed to support the coordination, integration, and standardization of scientific, technical, and bibliographic data of the U.S. Geological Survey (USGS). ESIS provides, through an online interactive computer system, referral to information about USGS data bases, data elements which are fields in the records of data bases, and systems. The data bases contain information about many subjects from several scientific disciplines such as: geology, geophysics, geochemistry, hydrology, cartography, oceanography, geography, minerals exploration and conservation, and satellite data sensing.

  7. 77 FR 19242 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

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

  8. Annual report of the Mizusawa Astrogeodynamics Observatory. Time Service and geophysical observations for the year 1991.

    NASA Astrophysics Data System (ADS)

    This annual report consists of two parts. The first part shows the results of the time services, i.e., time and latitude observations with the PZT, comparison of UTC(NAOM) with the Loran C and GPS (Global Positioning System), and comparison of the atomic clocks at the Mizusawa Astrogeodynamics Observatory. The second part shows the results of the geophysical observations at the Esashi Earth Tides Station and the absolute gravity measurements.

  9. Sainte Victoire Mountain - International Earth Science Olympiads

    NASA Astrophysics Data System (ADS)

    Berenguer, Jean-Luc

    2013-04-01

    The IESO is an annual competition for secondary school students. The students have to test their skills in all major areas of Earth sciences, including geology, geophysics, meteorology, oceanography, terrestrial astronomy and environmental sciences. The theoretical examination includes problems which are supposed to measure the participants' knowledge and understanding of Earth science areas. The practical examination consists of tasks which are designed to assess participants' abilities to carry out scientific investigations in earth science inquiries. he IESO is the only International Olympiad that includes an International Team Field Investigation. Each national team has also to present a special geological site from his country. This poster will show the fieldwork made with and by the French students/teachers team for the last IESO which took place in Argentina. The main aim of the IESO is to encourage students' interest and public awareness of Earth Science and to enhance Earth science learning.

  10. Content-Based Metadata Workbench: An innovative Tool to Compare Geophysical Parameters

    NASA Astrophysics Data System (ADS)

    Suresh, R.; Pfister, R.; Behnke, J.; Sachs, J.; D'Aria, D.

    2002-12-01

    Content Based Metadata Workbench (CBMW) is a prototype that seeks to improve the utility of information hidden in NASA's Earth science data systems by providing a global geophysical parameter data warehouse that is interoperable with metadata search systems. It will provide the following: a mechanism for content-based metadata searching of Earth science data, a research planning tool that includes inter-parameter visualization, and a broad warehouse of meaningful Earth science data to serve as a target for data mining. The team has just completed phase one of the prototype, which includes the development of CBMW data warehouse and integration of ordering interface and visualization of multiple parameters. CBMW takes an innovative approach to identify and compare anomalies and events from higher-level satellite remote sensing data products. CBMW has used level-3 Earth science data products and built a content-metadata "warehouse". This warehouse will serve as a data workbench for other data mining prototypes. CBMW used level 3 data products since they are based on widely accepted algorithms and relatively smaller in volume compared to lower level products. Using products from EOS Terra MODIS atmosphere data, TRMM fire and precipitation data, and AVHRR NDVI data, a database was developed to store geophysical parameters. The database was integrated with a GUI that enables detection of anomalies and relationships between multiple geophysical parameters through visualization. CBMW will provide the following: a mechanism for content-based Metadata searching of Earth science data, a research planning tool that includes inter-parameter visualization, and a broad warehouse of meaningful Earth science data to serve as a target for data mining. CBMW data warehouse is also interoperable with metadata search systems such as ECHO.

  11. Peace Education, ESD and the Earth Charter: Interconnections and Synergies

    ERIC Educational Resources Information Center

    Toh, Swee-Hin; Cawagas, Virginia Floresca

    2010-01-01

    This article provides a review of how the values and principles of the Earth Charter initiative relate to two specific innovative movements of educational transformation, namely peace education and education for sustainable development (ESD). The interconnections and synergies between these movements and the Earth Charter are highlighted.…

  12. The sixth presentation of the Maurice Ewing Medal by the American Geophysical Union and the United States Navy to Manik Talwani for leadership in marine geophysics

    NASA Astrophysics Data System (ADS)

    Uyeda, Seiya; Talwani, Manik

    Manik Talwani's impact on the geosciences clearly places him among those who deserve to be honored as a Ewing medalist. He has contributed major advances to our understanding of Earth's fundamental characteristics and has provided direction that will help guide geological/geophysical research long into the future.Born in Patiala, India, in 1933, Manik earned bachelor's and master's degrees at Delhi University. In the mid-1950s he moved to the United States and enrolled in Columbia University for his Ph.D. studies. It was the beginning of a long association between Manik and Columbia. When he earned his Ph.D. in 1959, it was already apparent that he was destined to make a significant impact on the geosciences. He has been the recipient of several important awards for his contributions and leadership. These include the first Krishnan Medal in 1965, from his home country, and the Macelwane Award from the American Geophysical Union, in 1967, for his pioneering achievements in the application of marine gravimetry to studies of Earth's crust and upper mantle. Since 1970, Manik has been a professor of geology at Columbia, and for 8 years he served as director of Lamont-Doherty Geological Observatory. This evening, for his continued contributions and leadership, Manik is being awarded the Maurice Ewing Medal. He is truly qualified for this distinction, based on his many important original contributions to marine geophysics, ocean technology and instrumentation, and also for his outstanding service to marine science.

  13. ORBSIM- ESTIMATING GEOPHYSICAL MODEL PARAMETERS FROM PLANETARY GRAVITY DATA

    NASA Technical Reports Server (NTRS)

    Sjogren, W. L.

    1994-01-01

    The ORBSIM program was developed for the accurate extraction of geophysical model parameters from Doppler radio tracking data acquired from orbiting planetary spacecraft. The model of the proposed planetary structure is used in a numerical integration of the spacecraft along simulated trajectories around the primary body. Using line of sight (LOS) Doppler residuals, ORBSIM applies fast and efficient modelling and optimization procedures which avoid the traditional complex dynamic reduction of data. ORBSIM produces quantitative geophysical results such as size, depth, and mass. ORBSIM has been used extensively to investigate topographic features on the Moon, Mars, and Venus. The program has proven particulary suitable for modelling gravitational anomalies and mascons. The basic observable for spacecraft-based gravity data is the Doppler frequency shift of a transponded radio signal. The time derivative of this signal carries information regarding the gravity field acting on the spacecraft in the LOS direction (the LOS direction being the path between the spacecraft and the receiving station, either Earth or another satellite). There are many dynamic factors taken into account: earth rotation, solar radiation, acceleration from planetary bodies, tracking station time and location adjustments, etc. The actual trajectories of the spacecraft are simulated using least squares fitted to conic motion. The theoretical Doppler readings from the simulated orbits are compared to actual Doppler observations and another least squares adjustment is made. ORBSIM has three modes of operation: trajectory simulation, optimization, and gravity modelling. In all cases, an initial gravity model of curved and/or flat disks, harmonics, and/or a force table are required input. ORBSIM is written in FORTRAN 77 for batch execution and has been implemented on a DEC VAX 11/780 computer operating under VMS. This program was released in 1985.

  14. Optimizing the design of geophysical experiments: Is it worthwhile?

    NASA Astrophysics Data System (ADS)

    Curtis, Andrew; Maurer, Hansruedi

    Determining the structure, composition, and state of the Earth's subsurface from measured data is the principal task of many geophysical experiments and surveys. Standard procedures involve the recording of appropriate data sets followed by the application of data analysis techniques to extract the desired information. While the importance of new tools for the analysis stage of an experiment is well recognized, much less attention seems to be paid to improving the data acquisition.A measure of the effort allocated to data analysis research relative to that devoted to data acquisition research is presented in Figure 1. Since 1955 there have been more than 10,000 publications on inversion methods alone, but in the same period only 100 papers on experimental design have appeared in journals. Considering that the acquisition component of an experiment defines what information will be contained in the data, and that no amount of data analysis can compensate for the lack of such information, we suggest that greater effort be made to improve survey planning techniques. Furthermore, given that logistical and financial constraints are often stringent and that relationships between geophysical data and model parameters describing the Earths subsurface are generally complicated, optimizing the design of an experiment may be quite challenging. Here we review experimental design procedures that optimize the benefit of a field survey, such that maximum information about the target structures is obtained at minimum cost. We also announce a new Web site and e-mail group set up as a forum for communication on survey design research and application.

  15. Geophysical Investigation of Oldoinyo Lengai

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  17. Rainbow Earth.

    ERIC Educational Resources Information Center

    Arizona State Dept. of Library and Archives, Phoenix.

    The environment is a great concern in the 1990s, and everyone needs to work at maintaining our planet. The 1992 Arizona State Library Reading Program, "Rainbow Earth," provides children with many techniques they can use to help the Earth. This reading program guide provides information on the following: goals, objectives, and evaluation;…

  18. Earth tides

    SciTech Connect

    Harrison, J.C.

    1984-01-01

    Nineteen papers on gravity, tilt, and strain tides are compiled into this volume. Detailed chapters cover the calculation of the tidal forces and of the Earth's response to them, as well as actual observations of earth tides. Partial Contents: On Earth tides. The tidal forces: Tidal Forces. New Computations of the Tide-Generating Potential. Corrected Tables of Tidal Harmonics. The Theory of Tidal Deformations. Body Tides on an Elliptical, Rotating, Elastic and Oceanless Earth, Deformation of the Earth by Surface Loads. Gravimetric Tidal Loading Computed from Integrated Green's Functions. Tidal Friction in the Solid Earth. Loading Tides Versus Body Tides. Lunar Tidal Acceleration from Earth Satellite Orbit Analysis. Observations: gravity. Tidal Gravity in Britain: Tidal Loading and the Spatial Distribution of the Marine Tide. Tidal Loading along a Profile Europe-East Africa-South Asia-Australia and the Pacific Ocean. Detailed Gravity-Tide Spectrum between One and Four Cycles per Day. Observations: tilt and strain. Cavity and Topographic Effects in Tilt and Strain Measurement. Observations of Local Elastic Effects on Earth Tide Tilts and Strains.

  19. Russian Meteorological and Geophysical Rockets of New Generation

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

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

  20. Earth observing satellite: Understanding the Earth as a system

    NASA Technical Reports Server (NTRS)

    Soffen, Gerald

    1990-01-01

    There is now a plan for global studies which include two very large efforts. One is the International Geosphere/Biosphere Program (IGBP) sponsored by the International Council of Scientific Unions. The other initiative is Mission to Planet Earth, an unbrella program for doing three kinds of space missions. The major one is the Earth Observation Satellite (EOS). EOS is large polar orbiting satellites with heavy payloads. Two will be placed in orbit by NASA, one by the Japanese and one or two by ESA. The overall mission measurement objectives of EOS are summarized: (1) the global distribution of energy input to and energy output from the Earth; (2) the structure, state variables, composition, and dynamics of the atmosphere from the ground to the mesopause; (3) the physical and biological structure, state, composition, and dynamics of the land surface, including terrestrial and inland water ecosystems; (4) the rates, important sources and sinks, and key components and processes of the Earth's biogeochemical cycles; (5) the circulation, surface temperature, wind stress, sea state, and the biological activity of the oceans; (6) the extent, type, state, elevation, roughness, and dynamics of glaciers, ice sheets, snow and sea ice, and the liquid equivalent of snow in the global cryosphere; (7) the global rates, amounts, and distribution of precipitation; and (8) the dynamic motions of the Earth (geophysics) as a whole, including both rotational dynamics and the kinematic motions of the tectonic plates.

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

    EPA Science Inventory

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

  2. What can earth tide measurements tell us about ocean tides or earth structure?

    NASA Technical Reports Server (NTRS)

    Baker, T. F.

    1978-01-01

    Current experimental problems in Earth tides are reviewed using comparisons of tidal gravity and tilt measurements in Europe with loading calculations are examples. The limitations of present day instrumentation and installation techniques are shown as well as some of the ways in which they can be improved. Many of the geophysical and oceanographic investigations that are possible with Earth tide measurements are discussed with emphasis on the percentage accuracies required in the measurements in order to obtain new information about Earth or its oceans.

  3. Movement - unpredictable or jerky

    MedlinePlus

    ... uncontrolled); Hyperkinetic movements References Jankovic J, Lang AE. Movement disorders. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta ... Elsevier Saunders; 2012:chap 21. Lang AE. Other movement disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  4. Understanding the lithosphere in complex tectonic scenarios by integrating geophysical data: The Pyrenees case study

    NASA Astrophysics Data System (ADS)

    Campanyà, Joan; Fullea, Javier; Ledo, Juanjo; Queralt, Pilar; Marcuello, Alex; Liesa, Montserrat; Muñoz, Josep Anton

    2016-04-01

    Tectonic processes dominate the development of the outermost layer of the Earth over a timescale of millions of years. The locations where these processes take place provide a great opportunity for Earth scientists to study and understand the dynamics and properties of the lithosphere. The Pyrenees are a particular case of continental collision formed as a result of the collision between the Iberian and European plates, which caused the subduction of the Iberian lower crust below the European crust. Large amounts of geophysical data have been acquired in the area providing spectacular images of lithospheric subduction beneath the Western and Central Pyrenees, confirming the occurrence of this generally well-understood process. The Eastern Pyrenees, however, are a most puzzling part of the orogen and the geodynamical evolution of this area cannot be understood without the influence of the Neogene Mediterranean rifting, following the continental collision. The complexity of this area and the controversy of the geophysical results set in debate concepts well recognized in the other parts of the Pyrenees such as the subduction of the Iberian lower crust and the depth of the lithosphere-asthenosphere boundary. The aims of this study are to characterise major tectonic and geophysical variations along the Pyrenean mountain range at a lithospheric-scale and constrain the causes of the observed lateral variations. A preliminary model of the lithospheric configuration and dynamics, based on magnetotelluric geophysical results, has been developed and constrained using independent and available geophysical, geological and geochemical data. Computational petrology methods, using Litmod, were used for integrated modelling of all data.

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

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev; Katz, Youri

    2014-05-01

    paleotectonic criteria for oil and gas discovery in this region. Extensive geological-geophysical investigations have been carried out in this region, and a significant number of deep boreholes have been drilled. However integrated estimation of the deep structure of the hydrocarbon host deposits and their space-time evolution in terms of the modern geodynamics (first of all, plate tectonics: Ben-Avraham and Ginzburg, 1990; Robertson, 1998; Ben-Avraham et al., 2002, 2006; Jimenez-Munt et al., 2003; Le Pichon and Kreemer, 2010), are comparatively recent (Eppelbaum and Katz, 2011, 2012a; Eppelbaum et al., 2012, 2014). We elucidate this geodynamic relationship by examining the structural floors within the following tectonic-geophysical zones: (1) regions of development of continental crust of the Nubian, Arabian and Sinai plates, (2) remaining oceanic crust of the eastern Mediterranean, and (3) the thinned continental crust of the terrane belt. A series of new gravity and magnetic maps developed by employing satellite and airborne data (as well their transformations) accompanied by tectonic schemes were constructed (Eppelbaum and Katz, 2011; Eppelbaum et al., 2012a, 2012b, 2014). These new maps are crucial to a better understanding of the dynamics of hydrocarbon basin formation within the continental and shelf depressions, as well as the deep depressions of the easternmost Mediterranean where gas deposits in zones of oceanic crust evolution have only recently (April 2013) begun to be exploited. Careful attention should be paid to the blocks of oceanic (basaltic) crust with reverse magnetization that were discovered (Ben-Avraham et al., 2002; Eppelbaum, 2006). This issue was very briefly (Eppelbaum and Katz, 2012a) explained as paleomagnetic Kiama zone of inverse polarity and demands separate consideration. An integrated magnetic-gravity-seismic analysis conducted along three interpretation profiles unambiguously indicates the presence of blocks of the Earth's crust with reverse

  6. Tamara Shapiro Ledley Receives 2013 Excellence in Geophysical Education Award: Citation

    NASA Astrophysics Data System (ADS)

    Reiff, Patricia

    2014-01-01

    It gives me great pleasure to cite Tamara Shapiro Ledley for the AGU Excellence in Geophysical Education Award "for her outstanding sustained leadership in Earth systems and climate change education." Tamara has shown an ongoing commitment to bridging the scientific and educational communities to make geophysical science knowledge and data accessible and usable to teachers and students and by extension to all citizens. She works extensively with both the scientific and educational communities. She began her educational work in 1990 as the leader for weather and climate in my Teacher Research program at Rice University. She continued as the lead for atmospheric sciences in our projects Earth Today and Museums Teaching Planet Earth, which introduced her to the Earth Science Information Partners (ESIP Federation). She has served many roles at ESIP, including creating the Standing Committee for Education and serving as vice president. ESIP recognized her many accomplishments with its President's Award in 2012. At TERC her education and outreach efforts have blossomed. She was the lead author of the "Earth as a System" investigation of the GLOBE Teacher's Guide. She was a member of the original Digital Library for Earth System Education (DLESE) Data Access Working Group in 2001, where the idea for a cookbook-like resource to facilitate the use of Earth science data by teachers and students resulted in her leading the development of the "Earth Exploration Toolbook" (EET), which allows teachers to easily access and use real scientific data in the classroom. Her efforts were recognized with the EET being awarded Science Magazine's Science Prize for Online Research in Education in 2011.

  7. Brief overview of geophysical probing technology

    SciTech Connect

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

    1982-02-01

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

  8. Surveying the earth's resources from space

    USGS Publications Warehouse

    Pecora, William T.

    1967-01-01

    Two developments, aerial photography and airborne geophysical surveying techniques, have already increased the rate at which new knowledge of the world's resources can be acquired. But even with far wider use of the tools and techniques already available, the problems that face us are greater than our current ability to solve them. Fortunately, some of the further acceleration required can be obtained through use of remote-sensing devices mounted in high-flying aircraft and earth-orbiting satellites.

  9. Measuring Orientation Of The Earth With GPS

    NASA Technical Reports Server (NTRS)

    Freedman, Adam P.

    1992-01-01

    Report discusses feasibility of using Global Positioning System (GPS) to resolve short-term fluctuations (days or hours) in locations of points on crust of Earth to within centimeters or millimeters. With full constellation of satellites and ground receiving stations, system provides rapid (within 12 hours) determinations of variations in orientation. Measurements used to enhance precision of spacecraft navigation and in geophysical and meteorological studies of daily exchanges of angular momentum among fluid core, crust and mantle, oceans, and atmosphere.

  10. Discover Earth

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Discover Earth is a NASA-funded project for teachers of grades 5-12 who want to expand their knowledge of the Earth system, and prepare to become master teachers who promote Earth system science in their own schools, counties, and throughout their state. Participants from the following states are invited to apply: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and Washington, DC. Teachers selected for the project participate in a two-week summer workshop conducted at the University of Maryland, College Park; develop classroom-ready materials during the workshop for broad dissemination; conduct a minimum of two peer training activities during the coming school year; and participate in other enrichment/education opportunities as available and desired. Discover Earth is a team effort that utilizes expertise from a range of contributors, and balances science content with hands-on classroom applications.

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

    USGS Publications Warehouse

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

    2002-01-01

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

  12. Modeling of the Earth's gravity field using the New Global Earth Model (NEWGEM)

    NASA Technical Reports Server (NTRS)

    Kim, Yeong E.; Braswell, W. Danny

    1989-01-01

    Traditionally, the global gravity field was described by representations based on the spherical harmonics (SH) expansion of the geopotential. The SH expansion coefficients were determined by fitting the Earth's gravity data as measured by many different methods including the use of artificial satellites. As gravity data have accumulated with increasingly better accuracies, more of the higher order SH expansion coefficients were determined. The SH representation is useful for describing the gravity field exterior to the Earth but is theoretically invalid on the Earth's surface and in the Earth's interior. A new global Earth model (NEWGEM) (KIM, 1987 and 1988a) was recently proposed to provide a unified description of the Earth's gravity field inside, on, and outside the Earth's surface using the Earth's mass density profile as deduced from seismic studies, elevation and bathymetric information, and local and global gravity data. Using NEWGEM, it is possible to determine the constraints on the mass distribution of the Earth imposed by gravity, topography, and seismic data. NEWGEM is useful in investigating a variety of geophysical phenomena. It is currently being utilized to develop a geophysical interpretation of Kaula's rule. The zeroth order NEWGEM is being used to numerically integrate spherical harmonic expansion coefficients and simultaneously determine the contribution of each layer in the model to a given coefficient. The numerically determined SH expansion coefficients are also being used to test the validity of SH expansions at the surface of the Earth by comparing the resulting SH expansion gravity model with exact calculations of the gravity at the Earth's surface.

  13. Basic research and data analysis for the earth and ocean physics applications program and for the National Geodetic Satellite Program

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Data analysis and supporting research in connection with the following objectives are discussed: (1) provide a precise and accurate geometric description of the earth's surface, (2) provide a precise and accurate mathematical description of the earth's gravitational field, and (3) determine time variations of the geometry of the ocean surface, the solid earth, the gravity field and other geophysical parameters.

  14. Digital Earth

    NASA Astrophysics Data System (ADS)

    de La Beaujardiere, J.

    2001-05-01

    Digital Earth (DE) seeks to make geospatial information broadly and easily available. Vast amounts of natural and cultural information are gathered about the Earth, but it is often difficult to find needed data, to share knowledge across disciplines, and to combine information from several sources. DE defines a framework for interoperability by selecting relevant open standards from the information technology community. These standards specify the technical means by which publishers can provide or sell their data, and by which client applications can find and access data in an automated fashion. The standardized DE framework enables many types of clients--from web browsers to museum kiosks to research-grade virtual environments--to use a common geospatial information infrastructure. Digital Earth can benefit Earth system education in general, and DLESE in particular, in several ways. First, educators, students and creators of instructional material will benefit from standardized access to georeferenced data. Secondly, educational lesson plans that focus on a region or aspect of the Earth can themselves be considered geospatial information resources that could be cataloged and retrieved through DE. Finally, general public knowledge about our planet will by increased by Digital Earth.

  15. Laser ranging contributions to monitoring and interpreting Earth orientation changes

    NASA Technical Reports Server (NTRS)

    Gross, R. S.

    2002-01-01

    The groundwork for a new field in the geophysical sciences - space geodesy - was laid in the 1960s with the development of satellite and lunar laser ranging systems, along with the development of very long baseline interferometry systems, for the purpose of studying crustal plate motion and deformation, the Earth's gravitational field, and Earth orientation changes. The availability of accurate, routine determinations of the Earth orientation parameters (EOPs) afforded by the launch of the LAser GEOdynamics Satellite (LAGEOS) on May 4, 1976, and the subsequent numerous studies of the LAGEOS observations, has led to a greater understanding of the causes of the observed changes in the Earth's orientation.

  16. A case for catastrophic early degassing of the earth.

    NASA Technical Reports Server (NTRS)

    Fanale, F. P.

    1971-01-01

    Evidence is given for the occurrence in early earth history of massive escape of volatiles from the interior of the earth to its surface, which must have had catastrophic proportions. The mechanism and time of this event are inferred from the abundances and distribution of volatiles in the atmosphere, hydrosphere and crust, and from meteorite studies, and geophysical and astronomical observations. This event is linked to the melting of the earth during accretion which resulted in the concentration of U, Th, K and Pb in the outermost portion of the earth and in virtually complete expulsion of nonradiogenic Ar, Ne and Kr from its interior.

  17. Aristoteles - An ESA mission to study the earth's gravity field

    NASA Astrophysics Data System (ADS)

    Lambeck, K.

    In preparing for its first Solid-Earth Program, ESA has studied a satellite concept for a mission dedicated to the precise determination of the earth's geopotential (gravitational and magnetic) fields. Data from such a mission are expected to make substantial contributions to a number of research and applications fields in solid-earth geophysics, oceanography and global-change monitoring. The impact of a high-resolution gravity-field mission on studies of the various earth-science problems is assessed. The current state of our knowledge in this area is discussed and the ability of low-orbit satellite gradiometry to contribute to their solution is demonstrated.

  18. Satellite-tracking and Earth dynamics research programs

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The major focus for operations during this period was the preliminary MERIT Campaign and its intensive tracking of LAGEOS for polar motion and Earth rotation studies. The data acquired from LAGEOS were used for other geophysical investigations, including studies of crustal dynamics, and Earth and ocean tides, and for the general development of precision orbit determination. The network performed regular tracking of several other retroreflector satellites including GEOS-1, GEOS-3, BE-C, and Starlette for refined determinations of station coordinates and Earth's gravity field and for studies of solid Earth dynamics.

  19. GETMAG - A New Geophysical Tool

    NASA Astrophysics Data System (ADS)

    Schmidt, P.; Clark, D.; Bick, M.; Binks, R.; Du, J.; Foley, C.; Gnanarajan, S.; Leslie, K.; Sullivan, P.; Thorn, B.; Tilbrook, D.

    2004-05-01

    CSIRO is developing a new instrument for mineral exploration. The instrument, GETMAG, measures the magnetic gradient tensor and the components of the magnetic field. The sensors are high temperature superconducting quantum interference devices (SQUIDs), or HTSs. The acronym is largely historical and stands for Glass Earth Tensor Magnetic Airborne Gradiometer. The GETMAG instument measures magnetic gradients via a novel application of high temperature superconducting tape flip-chipped onto a SQUID sensor. A gradiometer structure incorporating two opposing pick-up loops is patterned onto a tape. Due to the spatial separation of these loops, a magnetic gradient will produce a Meissner shielding current in the tape. The current is magnetically coupled to the SQUID sensor thus providing a direct measurement of the magnetic gradient. The tape is rotated to detect all gradients orthogonal to the axis of rotation. Three rotating tape systems are required to measure the full tensor. The gradients in combination with the TMI yield better resolution for magnetic surveys. Direction to individual sources and their magnetic moments (reduced according to distance) can be determined directly from the tensor. Results from test surveys, where the GETMAG system was rotated manually, show that the gradient can be measured to an accuracy of a few nT/m. It is estimated that improving the mechanical structure, spinning the system at about 600 rpm and using an improved data extraction algorithm can reduce this noise figure by two orders of magnitude. The vector components at this stage are very inaccurate since most of the development undertaken to date has been aimed at measuring the gradients. The systems operate better as gradiometers than as magnetometers and will not challenge total field instruments such as proton precession or alkali-vapour magnetometers as scalar instruments. The GETMAG concept has wide ranging applications in mineral exploration, environmental studies, ordnance

  20. Evaluation of borehole geophysical logs at the Sharon Steel Farrell Works Superfund site, Mercer County, Pennsylvania

    USGS Publications Warehouse

    McAuley, Steven D.

    2004-01-01

    On April 14?15, 2003, geophysical logging was conducted in five open-borehole wells in and adjacent to the Sharon Steel Farrell Works Superfund Site, Mercer County, Pa. Geophysical-logging tools used included caliper, natural gamma, single-point resistance, fluid temperature, and heatpulse flowmeter. The logs were used to determine casing depth, locate subsurface fractures, identify water-bearing fractures, and identify and measure direction and rate of vertical flow within the borehole. The results of the geophysical logging were used to determine the placement of borehole screens, which allows monitoring of water levels and sampling of water-bearing zones so that the U.S. Environmental Protection Agency can conduct an investigation of contaminant movement in the fractured bedrock. Water-bearing zones were identified in three of five boreholes at depths ranging from 46 to 119 feet below land surface. Borehole MR-3310 (MW03D) showed upward vertical flow from 71 to 74 feet below land surface to a receiving zone at 63-68 feet below land surface, permitting potential movement of ground water, and possibly contaminants, from deep to shallow zones. No vertical flow was measured in the other four boreholes.

  1. Invariant-tori-like Lagrangian coherent structures in geophysical flows.

    PubMed

    Beron-Vera, Francisco J; Olascoaga, María J; Brown, Michael G; Koçak, Huseyin; Rypina, Irina I

    2010-03-01

    The term "Lagrangian coherent structure" (LCS) is normally used to describe numerically detected structures whose properties are similar to those of stable and unstable manifolds of hyperbolic trajectories. The latter structures are invariant curves, i.e., material curves of fluid that serve as transport barriers. In this paper we use the term LCS to describe a different type of structure whose properties are similar to those of invariant tori in certain classes of two-dimensional incompressible flows. Like stable and unstable manifolds, invariant tori are invariant curves that serve as transport barriers. There are many differences, however, between traditional LCSs and invariant-tori-like LCSs. These differences are discussed with an emphasis on numerical techniques that can be used to identify invariant-tori-like LCSs. Structures of this type are often present in geophysical flows where zonal jets are present. A prime example of an invariant-torus-like LCS is the transport barrier near the core of the polar night jet in the Earth's lower and middle stratospheres in the austral winter and early spring; this is the barrier that traps ozone-depleted air inside the ozone hole. This example is investigated using both a simple analytically prescribed flow and a velocity field produced by a general circulation model of the Earth's atmosphere.

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

    NASA Astrophysics Data System (ADS)

    Eppelbaum, L. V.

    2009-04-01

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

  3. The interior of the Earth, an elementary description

    USGS Publications Warehouse

    Robertson, Eugene C.

    1966-01-01

    Evidence on the structure and composition of the earth's interior comes from (1) observations of surface rocks, (2) geophysical data from earthquakes, flow of heat from the interior, the magnetic field, and gravity, (3) laboratory experiments on surface rocks and minerals, and (4) comparison of the earth with other planets, the sun, stars, and meteorites. The major structural components in the earth that are separated by sharp discontinuities are the crust, the mantle, and the core. The crust forms a very thin surface skin, the mantle is a thick shell that extends half the radius down into the earth, and the core occupies the central part. The crust and upper mantle are known to vary in physical and chemical characteristics, both horizontally and vertically; the lower mantle and core are generally assumed to be uniform because their diagnostic geophysical phenomena are masked by the physical properties of the upper layers.

  4. Using Geophysical Data in the Texas High School Course, Geology, Meteorology, and Oceanography

    NASA Astrophysics Data System (ADS)

    Ellins, K.; Olson, H.; Pulliam, J.; Schott, M. J.

    2002-12-01

    Science educators working directly with scientists to develop inquiry-based instructional materials in Earth science yield some of the best results. The TEXTEAMS (Texas Teachers Empowered for Achievement in Mathematics and Science) Leadership Training for the Texas high school science course, Geology, Meteorology and Oceanography (GMO) is one example of a successful program that provides high-quality training to master teachers using geophysical data collected by scientists at The University of Texas Institute for Geophysics (UTIG). TEXTEAMS is a certification program of professional development and leadership training sponsored by the National Science Foundation that is part of the Texas Statewide Systemic Initiative. UTIG scientists teamed with science educators at the Charles A. Dana Center for Mathematics and Science Education at UT and the Texas Education Agency to develop inquiry-based instructional materials for eight GMO modules. Our learning activities help students and teachers understand how Earth scientists interpret the natural world and test their hypotheses, and provide opportunities for the use of technology in classroom science learning; they are aligned with national and state teaching standards. Examples of TEXTEAMS GMO learning activities that use geophysical data. 1. Neotectonics: radiocarbon dates and elevation above current sea level of raised coral reefs in the New Georgia Islands are used to calculate rates of tectonic uplift and as a basis for the development of a conceptual model to explain the pattern of uplift that emerges from the data. 2. Large Igneous Provinces:geophysical logging data collected on ODP Leg 183 (Kerguelen Plateau) are analyzed to identify the transition from sediment to basement rock. 3. The Search for Black Gold: petroleum exploration requires the integration of geology, geophysics, petrophysics and geochemistry. Knowledge gained in previous GMO modules is combined with fundamental knowledge about economics to

  5. Earth: Earth Science and Health

    NASA Technical Reports Server (NTRS)

    Maynard, Nancy G.

    2001-01-01

    A major new NASA initiative on environmental change and health has been established to promote the application of Earth science remote sensing data, information, observations, and technologies to issues of human health. NASA's Earth Sciences suite of Earth observing instruments are now providing improved observations science, data, and advanced technologies about the Earth's land, atmosphere, and oceans. These new space-based resources are being combined with other agency and university resources, data integration and fusion technologies, geographic information systems (GIS), and the spectrum of tools available from the public health community, making it possible to better understand how the environment and climate are linked to specific diseases, to improve outbreak prediction, and to minimize disease risk. This presentation is an overview of NASA's tools, capabilities, and research advances in this initiative.

  6. Satellite tracking and earth dynamics research programs

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The SAO laser site in Arequipa continued routine operations throughout the reporting period except for the months of March and April when upgrading was underway. The laser in Orroral Valley was operational through March. Together with the cooperating stations in Wettzell, Grasse, Kootwikj, San Fernando, Helwan, and Metsahove the laser stations obtained a total of 37,099 quick-look observations on 978 passes of BE-C, Starlette, and LAGEOS. The Network continued to track LAGEOS at highest priority for polar motion and Earth rotation studies, and for other geophysical investigations, including crustal dynamics, Earth and ocean tides, and the general development of precision orbit determination. The Network performed regular tracking of BE-C and Starlette for refined determinations of station coordinate and the Earth's gravity field and for studies of solid earth dynamics. Monthly statistics of the passes and points are given by station and by satellite.

  7. Digital geologic and geophysical data of Bangladesh

    USGS Publications Warehouse

    Persits, Feliks M.; Wandrey, C.J.; Milici, R.C.; Manwar, Abdullah

    1997-01-01

    The data set for these maps includes arcs, polygons, and labels that outline and describe the general geologic age and geophysical fields of Bangladesh. Political boundaries are provided to show the general location of administrative regions and state boundaries. Major base topographic data like cities, rivers, etc. were derived from the same paper map source as the geology.

  8. Movement disorders and sleep.

    PubMed

    Driver-Dunckley, Erika D; Adler, Charles H

    2012-11-01

    This article summarizes what is currently known about sleep disturbances in several movement disorders including Parkinson disease, essential tremor, parkinsonism, dystonia, Huntington disease, myoclonus, and ataxias. There is an association between movement disorders and sleep. In some cases the prevalence of sleep disorders is much higher in patients with movement disorder, such as rapid eye movement sleep behavior disorder in Parkinson disease. In other cases, sleep difficulties worsen the involuntary movements. In many cases the medications used to treat patients with movement disorder disturb sleep or cause daytime sleepiness. The importance of discussing sleep issues in patients with movement disorders cannot be underestimated.

  9. On the Reference Pole for Earth Orientation and UT1

    DTIC Science & Technology

    2000-03-01

    precession-nutation and the geophysically induced rotation variations (such as the Chandler wobble ) as low frequency signals from VLBI data. Remember...directly from the kinematical relations connecting the Earth rotation parameters (spin rate variation, and wobble ) to the Earth orientation parameters. 2...r+1) in (9). In particular, one has a term ~Xr+1;e i(r+1) 0t corresponding to a wobble of frequency 0 and amplitude ~m(); ( = r+ ): ~Xr+1

  10. Geophysics applications in critical zone science: emerging topics

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Geophysical Constraints on Sediment Dispersal Systems

    NASA Astrophysics Data System (ADS)

    Johnstone, Elizabeth Anne Carruthers

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

  12. Geophysical Technologies to Image Old Mine Works

    SciTech Connect

    Kanaan Hanna; Jim Pfeiffer

    2007-01-15

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

  13. 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

  14. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    NASA Astrophysics Data System (ADS)

    Abbas, M.; Jardani, A.

    2015-12-01

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

  15. 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

  16. Application of advanced borehole geophysical logging to managed aquifer recharge investigations

    NASA Astrophysics Data System (ADS)

    Maliva, Robert G.; Clayton, Edward A.; Missimer, Thomas M.

    2009-09-01

    Communities and water utilities are increasingly being forced to implement more hydrogeologically complex alternative water supply and storage options to meet increasing freshwater demands. The performance of managed aquifer recharge projects, including aquifer storage and recovery, is controlled by the movement and mixing of stored freshwater and native groundwater, and fluid-rock interactions, which, in turn, are strongly influenced by aquifer heterogeneity. Advanced borehole geophysical logging techniques developed for the oil and gas industry such as neutron-gamma ray spectroscopy, microresistivity imaging, and nuclear magnetic resonance, can provide hitherto unavailable fine-scale data on porosity (total and effective), hydraulic conductivity, salinity, and the mineralogical composition of aquifers. Data on aquifer heterogeneity obtained from advanced borehole geophysics logs, combined with information on larger-scale aquifer hydraulics obtained from pumping tests, have the potential for improving aquifer characterization and modeling needed for feasibility assessments and the design and optimization of the operation of managed aquifer recharge systems.

  17. Water Detection Response Team Geophysics Element Case Histories

    DTIC Science & Technology

    1990-09-01

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

  18. Physics of the earth: A new approach to some problems

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Vladimir V.; Semakov, Nikolai N.; Dorovskii, Vitalii N.; Kotliar, Petr E.

    Using results of geodynamic observations, the monograph discusses the energetics of the earth which determine its physical processes, such as heat fluxes, dynamism, nonuniformity of rotation, volcanism, and seismicity, as well as its magnetic field, anomalies, and poles. Models of these processes are developed which make it possible to formulate novel interpretations of available geophysical data and to account for their correlations.

  19. Biomechanics of foetal movement.

    PubMed

    Nowlan, N C

    2015-01-02

    Foetal movements commence at seven weeks of gestation, with the foetal movement repertoire including twitches, whole body movements, stretches, isolated limb movements, breathing movements, head and neck movements, jaw movements (including yawning, sucking and swallowing) and hiccups by ten weeks of gestational age. There are two key biomechanical aspects to gross foetal movements; the first being that the foetus moves in a dynamically changing constrained physical environment in which the freedom to move becomes increasingly restricted with increasing foetal size and decreasing amniotic fluid. Therefore, the mechanical environment experienced by the foetus affects its ability to move freely. Secondly, the mechanical forces induced by foetal movements are crucial for normal skeletal development, as evidenced by a number of conditions and syndromes for which reduced or abnormal foetal movements are implicated, such as developmental dysplasia of the hip, arthrogryposis and foetal akinesia deformation sequence. This review examines both the biomechanical effects of the physical environment on foetal movements through discussion of intrauterine factors, such as space, foetal positioning and volume of amniotic fluid, and the biomechanical role of gross foetal movements in human skeletal development through investigation of the effects of abnormal movement on the bones and joints. This review also highlights computational simulations of foetal movements that attempt to determine the mechanical forces acting on the foetus as it moves. Finally, avenues for future research into foetal movement biomechanics are highlighted, which have potential impact for a diverse range of fields including foetal medicine, musculoskeletal disorders and tissue engineering.

  20. Multi-Disciplinary Applications of Oceanographic Geophysical Data Collection

    NASA Astrophysics Data System (ADS)

    Soule, Dax Christian

    Geophysical data and methods are a key source for information about geologic features beneath the seafloor that are difficult to sample directly. Our knowledge of the Earth's structure has largely relied on our ability to apply classical physics to study the Earth's through the transmission of seismic and electromagnetic waves. As our data collection capabilities have benefited from technological advancements in connectivity, bandwidth, power usage, battery life and data storage, the scope of questions that can be addressed using seismology and other techniques is broadening. Larger data sets and increased bandwidth offer opportunities to explore multiple questions with individual data streams. This dissertation explores using seismology and other sources of time series data both as tools for exploring novel science questions but also as tools for teaching Earth science to students as they develop Science, Technology, Engineering, and Mathematics (STEM) skills. These analyses (1) create a model of crustal thickness and lower crustal velocities for crustal ages of 0.1-1.2 Ma on the Endeavour Segment of the Juan de Fuca Ridge by inverting travel times of crustal paths and non-ridge-crossing wide-angle Moho reflections obtained from a three-dimensional tomographic experiment; (2) use fin whale calls recorded by a seafloor seismic network on the Endeavour segment of the Juan de Fuca Ridge to create over 150 whale tracks using new techniques and identify four characteristic inter-pulse intervals (IPIs) that indicate group size and swimming speed and direction; and (3) engage students in analysis of data collected by networks of environmental sensors, which are used to study various natural phenomena, such as nutrient loading, climate change, and stream discharge to compare approaches to implementation in an undergraduate time-series analysis course. These results demonstrate the utility of seafloor networks as both instruments of primary data collection and teaching

  1. Field Geophysics Class at Volcán Tungurahua, Ecuador

    NASA Astrophysics Data System (ADS)

    Johnson, Jeffrey; Ruiz, Mario

    2009-11-01

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

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

    PubMed

    Foster, Russell G; Roenneberg, Till

    2008-09-09

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

  3. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  4. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  5. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  6. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  7. 36 CFR 902.59 - Geological and geophysical information.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  8. 3-D object-oriented image analysis of geophysical data

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  9. Digital Earth - A sustainable Earth

    NASA Astrophysics Data System (ADS)

    Mahavir

    2014-02-01

    All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth.

  10. Review of Solar-Geophysical Data for the October-November 2003 Events

    NASA Astrophysics Data System (ADS)

    Coffey, H.; Erwin, E.

    2004-05-01

    Historical data show a number of extraordinary solar-geophysical events occurring on the declining phase of the solar cycle. Though beyond the time period of high solar maximum, the Sun manages to develop some awesome sunspot groups which seem to come out of nowhere, pummeling us with all kinds of geoeffective impacts. Geomagnetic superstorms occurring during the declining solar activity phase include 1960/11/12, 1972/08/04, 1982/07/13, 1992/05/10 and now 2003/10/29 and following. We review the October/November 2003 solar activity in different wavelengths and their geomagnetic and cosmic ray effects on Earth. Data are available on the web at Solar-Geophysical Data (SGD) PDF version http://sgd.ngdc.noaa.gov and/or on the NGDC ftp site at ftp://ftp.ngdc.noaa.gov/STP/.

  11. Think Earth.

    ERIC Educational Resources Information Center

    Niedermeyer, Fred; Ice, Kay

    1992-01-01

    Describes a series of environmental education instructional units for grades K-6 developed by the Think Earth Consortium that cover topics such as conservation, pollution control, and waste reduction. Provides testimony from one sixth-grade teacher that field tested the second-grade unit. (MDH)

  12. Rare earths

    USGS Publications Warehouse

    Gambogi, J.

    2013-01-01

    Global mine production of rare earths was estimated to have declined slightly in 2012 relative to 2011 (Fig. 1). Production in China was estimated to have decreased to 95 from 105 kt (104,700 from 115,700 st) in 2011, while new mine production in the United States and Australia increased.

  13. The Earth's Plamasphere

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.

    2015-01-01

    The Earth's plasmasphere is an inner part of the magneteosphere. It is located just outside the upper ionosphere located in Earth's atmosphere. It is a region of dense, cold plasma that surrounds the Earth. Although plasma is found throughout the magnetosphere, the plasmasphere usually contains the coldest plasma. Here's how it works: The upper reaches of our planet's atmosphere are exposed to ultraviolet light from the Sun, and they are ionized with electrons that are freed from neutral atmospheric particles. The results are electrically charged negative and positive particles. The negative particles are electrons, and the positive particles are now called ions (formerly atoms and molecules). If the density of these particles is low enough, this electrically charged gas behaves differently than it would if it were neutral. Now this gas is called plasma. The atmospheric gas density becomes low enough to support the conditions for a plasma around earth at about 90 kilometers above Earth's surface. The electrons in plasma gain more energy, and they are very low in mass. They move along Earth's magnetic field lines and their increased energy is enough to escape Earth's gravity. Because electrons are very light, they don't have to gain too much kinetic energy from the Sun's ultraviolet light before gravity loses its grip on them. Gravity is not all that holds them back, however. As more and more electrons begin to escape outward, they leave behind a growing net positive electric charge in the ionosphere and create a growing net negative electric charge above the ionosphere; an electric field begins to develop (the Pannekoek-Rosseland E-field). Thus, these different interacting charges result in a positively charged ionosphere and negatively charged region of space above it. Very quickly this resulting electric field opposed upward movement of the electrons out of the ionosphere. The electrons still have this increased energy, however, so the electric field doesn't just

  14. Earth meandering

    NASA Astrophysics Data System (ADS)

    Asadiyan, H.; Zamani, A.

    2009-04-01

    In this paper we try to put away current Global Tectonic Model to look the tectonic evolution of the earth from new point of view. Our new dynamic model is based on study of river meandering (RM) which infer new concept as Earth meandering(EM). In a universal gravitational field if we consider a clockwise spiral galaxy model rotate above Ninety East Ridge (geotectonic axis GA), this system with applying torsion field (likes geomagnetic field) in side direction from Rocky Mt. (west geotectonic pole WGP) to Tibetan plateau TP (east geotectonic pole EGP),it seems that pulled mass from WGP and pushed it in EGP due to it's rolling dynamics. According to this idea we see in topographic map that North America and Green land like a tongue pulled from Pacific mouth toward TP. Actually this system rolled or meander the earth over itself fractaly from small scale to big scale and what we see in the river meandering and Earth meandering are two faces of one coin. River transport water and sediments from high elevation to lower elevation and also in EM, mass transport from high altitude-Rocky Mt. to lower altitude Himalaya Mt. along 'S' shape geodetic line-optimum path which connect points from high altitude to lower altitude as kind of Euler Elastica(EE). These curves are responsible for mass spreading (source) and mass concentration (sink). In this regard, tiltness of earth spin axis plays an important role, 'S' are part of sigmoidal shape which formed due to intersection of Earth rolling with the Earth glob and actual feature of transform fault and river meandering. Longitudinal profile in mature rivers as a part of 'S' curve also is a kind of EE. 'S' which bound the whole earth is named S-1(S order 1) and cube corresponding to this which represent Earth fracturing in global scale named C-1(cube order 1 or side vergence cube SVC), C-1 is a biggest cycle of spiral polygon, so it is not completely closed and it has separation about diameter of C-7. Inside SVC we introduce cone

  15. Mechanical obstacles to the movement of continent-bearing plates

    NASA Technical Reports Server (NTRS)

    Lowman, P. D., Jr.

    1985-01-01

    Selected geophysical problems associated with the concept of continental drift as an incidental corollary of plate movement are discussed. The problems include the absence of a suitable plate-driving mechanism for plates with continental leading edges, the absence of the low-velocity zone under shields, and continental roots of 400 to 700 km depths. It is shown that if continental drift occurs, it must use mechanisms not now understood, or that it may not occur at all, plate movement being confined to ocean basins.

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

    SciTech Connect

    GV Last; DG Horton

    2000-03-23

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

  17. Sessions on history of space and geophysics spark interest

    NASA Astrophysics Data System (ADS)

    Schröder, Wilfried

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

  18. Geophysical and Chemical Weathering Signatures Across the Deep Weathered-Unweathered Granite Boundary of the Calhoun Critical Zone Observatory

    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.

  19. Geophysical and fluid dynamical analyses in physical volcanology

    NASA Astrophysics Data System (ADS)

    Rogers, Patricia Grizzaffi

    Volcanism is a predominant process on the terrestrial planets, and studies of physical volcanologic processes provide fundamental insight into the evolution of a planet's surface and interior. This work combines theoretical modeling, field observations, and studies of planetary surfaces in an integrated approach to understanding the mechanical and dynamic processes associated with volcanism. By understanding the basic dynamics associated with terrestrial volcanic processes, we hope to better understand the evolution of other planetary surfaces for which only remote sensing data are available. The focus of this work is the physics of volcanism in space and time, with an emphasis on regions that are dominated by volcanism such as the Hawaiian islands, and on studies of lava flow emplacement. Applying our knowledge of volcanic processes on Earth to studies of Venusian geology and geophysics is also important for this investigation because volcanism has been a primary process in creating and modifying landforms on that planet. This analysis of geophysical and fluid dynamic processes associated with physical volcanology first focuses on the relationship between volcanic and tectonic processes and the associated stress environments. Specifically, through analytical modeling we investigate the regional stresses associated with Bell Regio, a volcanic highland on Venus, and structural features believed to be a consequence of lithospheric flexure due to volcanic loading. The relationship between the tectonic features surrounding a volcanic edifice and stresses associated with magma chamber inflation are also examined through finite element analysis. The implications of a change in volcanic style and lithospheric thickness over time are discussed. Next, factors that affect the dynamics of lava flow emplacement are examined through a combination ot theoretical modeling and field measurements. Downflow changes in rheology and lava channel formation under conditions of varying

  20. The Geophysical Fluid Flow Cell Experiment

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  1. The geophysical impact of the Aristoteles mission

    NASA Astrophysics Data System (ADS)

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

    1991-12-01

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

  2. Geophysical methods for monitoring infiltration in soil

    NASA Astrophysics Data System (ADS)

    Coquet, Yves; Pessel, Marc; Saintenoy, Albane

    2015-04-01

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

  3. FY97 Geophysics Technology Area Plan.

    DTIC Science & Technology

    1997-03-01

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

  4. Application of geophysical methods for fracture characterization

    SciTech Connect

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

    1990-01-01

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

  5. Some geologic observations concerning lunar geophysical models

    NASA Technical Reports Server (NTRS)

    Head, J. W.

    1977-01-01

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

  6. Using geophysics to characterize levee stability

    NASA Astrophysics Data System (ADS)

    Dalton, Laura M.

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

  7. Polarimetric remote sensing of geophysical medium structures

    NASA Astrophysics Data System (ADS)

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

    1993-11-01

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

  8. Geophysical mapping of solution and collapse sinkholes

    NASA Astrophysics Data System (ADS)

    Kaufmann, Georg

    2014-12-01

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

  9. Tectonic Plate Movement.

    ERIC Educational Resources Information Center

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  10. Functional Movement Disorder

    MedlinePlus

    ... that controls muscles during contraction and at rest. Electroencephalography (EEG) can correlate the movement and detect any ... that controls muscles during contraction and at rest. Electroencephalography (EEG) can correlate the movement and detect any ...

  11. Eye Movement Disorders

    MedlinePlus

    ... t work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... of the eyes, sometimes called "dancing eyes" Some eye movement disorders are present at birth. Others develop over ...

  12. Next step in Earth interior modeling for nutation

    NASA Astrophysics Data System (ADS)

    Dehant, V.; Folgueira, M.; Puica, M.; Koot, L.; Van Hoolst, T.; Trinh, A.

    2014-12-01

    Accurate reference systems are important for many geophysical applications and satellite observations. It is therefore necessary to know the Earth rotation and orientation with high precision. Interactions between the solid Earth and its fluid layers (liquid core, atmosphere, ocean) induce variations in the Earth's speed of rotation. In addition, because the Earth is not a perfect sphere, but rather an ellipsoid flattened at its poles, the combined gravitational forces acting upon it produce changes in the orientation of its spin axis. Precession describes the long-term trend in the orientation of the Earth, while nutation refers to shorter-term periodic variations. The nutations of the Earth are the prime focus of the present paper. Models are used to predict the real-time Earth rotation and orientation, based on past observations and theoretical considerations of geophysical processes. In particular, the coupling mechanisms at the internal boundaries have been shown to be important for rotation. We here address the coupling mechanisms at the core boundaries such as the topographic, electromagnetic and viscous couplings, and discuss improvements in their computation and observation. The study uses and compares numerical and semi-analytical approaches, with the objective of both improving the nutation model and the rotation, and better understanding the interior of the Earth.

  13. Integrated Geophysical Studies in the East-Indian Geothermal Province

    NASA Astrophysics Data System (ADS)

    Baranwal, V. C.; Sharma, S. P.

    2006-01-01

    Integrated geophysical surveys using vertical electrical sounding (VES), very low frequency (VLF) EM, radiation counting, total magnetic field and self-potential (SP) measurements are carried out to characterize the geothermal area around a hot spring in the Nayagarh district, Orissa, India that lies in the East Indian geothermal province. The study was performed to delineate the fracture pattern, contaminated groundwater movement and possible heating source. VES interpretations suggest a three- to four-layer structure in the area. Resistivity survey near the hot spring suggests that weathered and fractured formations constitute the main aquifer system and extend to 60 m depth. Current flow measured at various electrode separations normalized by the applied voltage suggests that fractures extend to a greater depth. Detailed VLF study shows that fractures extend beyond 70 m depth. VLF anomaly has also very good correlation with the total magnetic field measured along the same profiles. Study results suggest that a gridded pattern of VLF survey could map the underground conductive fracture zones that can identify the movement of contaminated groundwater flow. Therefore, precautionary measures can be taken to check further contamination by delineating subsurface conducting structures. Self potential (SP) measured over the hot spring does not show a large anomaly in favor of the presence of a sulphide mineral body. A small positive (5 15mV) SP anomaly is measured which may be streaming potential due to subsurface fluid flow. A high radiation is measured about four kilometers from the hot spring, suggesting possible radiogenic heating. However, the exact nature of the heating source and its depth is not known in the area. Deep resistivity followed by a magneto-telluric survey could reveal the deeper structures.

  14. Eye Movements of Flatfish for Different Gravity Condition

    NASA Astrophysics Data System (ADS)

    Iwata, Kaori; Takabayashi, Akira; Imada, Hideki; Miyachi, Ei-Ichi

    On Earth, gravity sensation plays a basic role for all of physiological phenomena in every creature. In microgravity, loss of gravity input causes many functional disorders in animals and humans. During adaptation to microgravity, otolith-mediated response such as eye movements would alter. Flatfish provide a natural model for the study of adaptive changes in the vestibuloocular reflex. During metamorphosis, vestibular and oculomotor coordinate of flatfish displaced 90 degrees about the longitudinal body axis. Therefore, it is expected that microgravity induce the sensory mismatch in adult flatfish. In this study, we analyzed the eye movements of normal and otolith removed flatfish for body tilting and the eye movements of normal flatfish during microgravity produced by parabolic aircraft flight. The fish was fixed on the tilting table controlled by computer. The eye movements for body tilting along the different body axis were video-recorded. The vertical and torsional eye rotations were analyzed frame by frame. In normal flatfish, torsional eye movements were larger for head up or head down tilting than leftward or rightward tilting. On the other hand, vertical eye movements were larger for leftward or rightward tilting than head up or head down tilting. After removal of left side utlicular otolith, the vertical eye movement for 180 degrees body tilting disappeared. For the changes of gravity, vertical eye movements were observed. These results suggested that eye movements of flatfish adapted to Earth's gravity condition and sacculus and lagena might play important role for otolith-ocular eye movements.

  15. NASA'S Earth Science Data Stewardship Activities

    NASA Technical Reports Server (NTRS)

    Lowe, Dawn R.; Murphy, Kevin J.; Ramapriyan, Hampapuram

    2015-01-01

    NASA has been collecting Earth observation data for over 50 years using instruments on board satellites, aircraft and ground-based systems. With the inception of the Earth Observing System (EOS) Program in 1990, NASA established the Earth Science Data and Information System (ESDIS) Project and initiated development of the Earth Observing System Data and Information System (EOSDIS). A set of Distributed Active Archive Centers (DAACs) was established at locations based on science discipline expertise. Today, EOSDIS consists of 12 DAACs and 12 Science Investigator-led Processing Systems (SIPS), processing data from the EOS missions, as well as the Suomi National Polar Orbiting Partnership mission, and other satellite and airborne missions. The DAACs archive and distribute the vast majority of data from NASA’s Earth science missions, with data holdings exceeding 12 petabytes The data held by EOSDIS are available to all users consistent with NASA’s free and open data policy, which has been in effect since 1990. The EOSDIS archives consist of raw instrument data counts (level 0 data), as well as higher level standard products (e.g., geophysical parameters, products mapped to standard spatio-temporal grids, results of Earth system models using multi-instrument observations, and long time series of Earth System Data Records resulting from multiple satellite observations of a given type of phenomenon). EOSDIS data stewardship responsibilities include ensuring that the data and information content are reliable, of high quality, easily accessible, and usable for as long as they are considered to be of value.

  16. Research and Teaching About the Deep Earth

    NASA Astrophysics Data System (ADS)

    Williams, Michael L.; Mogk, David W.; McDaris, John

    2010-08-01

    Understanding the Deep Earth: Slabs, Drips, Plumes and More; Virtual Workshop, 17-19 February and 24-26 February 2010; Images and models of active faults, subducting plates, mantle drips, and rising plumes are spurring new excitement about deep-Earth processes and connections between Earth's internal systems and plate tectonics. The new results and the steady progress of Earthscope's USArray across the country are also providing a special opportunity to reach students and the general public. The pace of discoveries about the deep Earth is accelerating due to advances in experimental, modeling, and sensing technologies; new data processing capabilities; and installation of new networks, especially the EarthScope facility. EarthScope is an interdisciplinary program that combines geology and geophysics to study the structure and evolution of the North American continent. To explore the current state of deep-Earth science and ways in which it can be brought into the undergraduate classroom, 40 professors attended a virtual workshop given by On the Cutting Edge, a program that strives to improve undergraduate geoscience education through an integrated cooperative series of workshops and Web-based resources. The 6-day two-part workshop consisted of plenary talks, large and small group discussions, and development and review of new classroom and laboratory activities.

  17. Cluster analysis applied to multiparameter geophysical dataset

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  18. Predicate Movements in Chinese

    ERIC Educational Resources Information Center

    Shou-hsin, Teng

    1975-01-01

    The movements of such higher predicates as time, locative, and complementation verbs are studied, and Tai's Predicate Placement Constraint is rejected as an incorrect account of predicate movements in Chinese. It is proposed, on the other hand, that there is only leftward movement involving predicates in Chinese. (Author)

  19. Linking Literacy and Movement

    ERIC Educational Resources Information Center

    Pica, Rae

    2010-01-01

    There are many links between literacy and movement. Movement and language are both forms of communication and self-expression. Rhythm is an essential component of both language and movement. While people may think of rhythm primarily in musical terms, there is a rhythm to words and sentences as well. Individuals develop an internal rhythm when…

  20. Eye Movements and Learning.

    ERIC Educational Resources Information Center

    Nesbit, Larry L.

    Research on the use of eye movement indices (such as number of fixations, the average fixation duration, and saccadic movements) as a measure of cognitive processing is reviewed in this paper. Information is provided on the physiology of the eye, computer applications to eye movement study, the influence of stimulus materials and intelligence on…

  1. Using geophysical techniques to control in situ thermal remediation

    SciTech Connect

    Boyd, S.; Daily, W.; Ramirez, A.; Wilt, M.; Goldman, R.; Kayes, D.; Kenneally, K.; Udell, K.; Hunter, R.

    1994-01-22

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

  2. Volcano Monitoring Using Google Earth

    NASA Astrophysics Data System (ADS)

    Bailey, J. E.; Dehn, J.; Webley, P.; Skoog, R.

    2006-12-01

    At the Alaska Volcano Observatory (AVO), Google Earth is being used as a visualization tool for operational satellite monitoring of the region's volcanoes. Through the abilities of the Keyhole Markup Language (KML) utilized by Google Earth, different datasets have been integrated into this virtual globe browser. Examples include the ability to browse thermal satellite image overlays with dynamic control, to look for signs of volcanic activity. Webcams can also be viewed interactively through the Google Earth interface to confirm current activity. Other applications include monitoring the location and status of instrumentation; near real-time plotting of earthquake hypocenters; mapping of new volcanic deposits; and animated models of ash plumes within Google Earth, created by a combination of ash dispersion modeling and 3D visualization packages. The globe also provides an ideal interface for displaying near real-time information on detected thermal anomalies or "hotspot"; pixels in satellite images with elevated brightness temperatures relative to the background temperature. The Geophysical Institute at the University of Alaska collects AVHRR (Advanced Very High Resolution Radiometer) and MODIS (Moderate Resolution Imaging Spectroradiometer) through its own receiving station. The automated processing that follows includes application of algorithms that search for hotspots close to volcano location, flagging those that meet certain criteria. Further automated routines generate folders of KML placemarkers, which are linked to Google Earth through the network link function. Downloadable KML files have been created to provide links to various data products for different volcanoes and past eruptions, and to demonstrate examples of the monitoring tools developed. These KML files will be made accessible through a new website that will become publicly available in December 2006.

  3. The use of airborne geophysics for levee classification and assessment

    NASA Astrophysics Data System (ADS)

    Dunbar, Joseph B.

    2011-12-01

    purpose for segmenting the levee system is for identifying reaches with similar geotechnical properties for an engineering evaluation and to identify areas where anomalous conditions may occur. Airborne geophysical methods offer added benefits and improvements over traditional engineering methods to evaluate levees based solely on evenly spaced borings along the levee right-of-way, where zones of weakness may be missed. The volume of earth being measured by multiple frequency airborne EM techniques corresponds primarily to the foundation of the levee instead of the body of the levee in smaller levees. Ideally, airborne methods would be supplemented with high resolution ground based EM methods to better define anomalous conditions. Data derived from airborne sur-veys are used in a levee screening process developed during this research to rank levees for the most efficient use of limited maintenance resources and subsequently target reaches for focused studies using traditional engineering methods. Airborne EM surveys show that local variations in electrical conductivity occur, and usually corre-spond to abrupt geologic boundaries in the levee foundation associated with different types of depositional environments (i.e., abandoned channel, abandoned course, point bar, flood basin, crevasse splay, chute, etc.).

  4. Cosmic Influence on the Sun-Earth Environment

    PubMed Central

    Mukherjee, Saumitra

    2008-01-01

    SOHO satellite data reveals geophysical changes before sudden changes in the Earth's Sun-Earth environment. The influence of extragalactic changes on the Sun as well as the Sun-Earth environment seems to be both periodic and episodic. The periodic changes in terms of solar maxima and minima occur every 11 years, whereas the episodic changes can happen at any time. Episodic changes can be monitored by cosmic ray detectors as a sudden increase or decrease of activity. During these solar and cosmic anomaly periods the environment of the Earth is affected. The Star-Sun-Earth connection has the potential to influence the thermosphere, atmosphere, ionosphere and lithosphere. Initial correlation of the cosmic and Sun-Earth connection has shown the possibility of predicting earthquakes, sudden changes in atmospheric temperatures and erratic rainfall/snowfall patterns. PMID:27873955

  5. Viscous stratification of the earth and convection

    NASA Technical Reports Server (NTRS)

    Elsasser, W. M.

    1972-01-01

    The shallow model of the earth's mantle is discussed along with a variety of geophysical arguments for its correctness and against the existence of deep convection. The main agrument is summarized in the proposal that the astheno sphere is less viscous (by a factor of 10 to 100) than has generally been assumed. In this shallow model, the return flow is essentially through the asthenosphere. The dynamical agent is the steep temperature gradient in the upper mantle. Speculations as to the historical variation of this gradient are advanced. The effects on the model of a nonuniform earth aggregation are considered and shown to favor shallow convection as well as a top convective layer (lithosphere plus asthenosphere) whose depth increases slowly over the earth's life, leading to a tectonic activity that increases gradually with time.

  6. Earth Sciences report, 1989--1990

    SciTech Connect

    Younker, L.W.; Peterson, S.J.; Price, M.E.

    1991-03-01

    The Earth Sciences Department at Lawrence Livermore National Laboratory (LLNL) conducts work in support of the Laboratory's energy, defense, environmental, and basic research programs. The Department comprises more than 100 professional scientific personnel spanning a variety of subdisciplines: geology, seismology, physics, geophysics, geochemistry, geohydrology, chemical engineering, and mechanical engineering. Resident technical support groups add significant additional technical expertise, including Containment Engineering, Computations, Electronic Engineering, Mechanical Engineering, Chemistry and Materials Science, and Technical Information. In total, approximately 180 professional scientists and engineers are housed in the Earth Sciences Department, making it one of the largest geo-science research groups in the nation. Previous Earth Sciences reports have presented an outline of the technical capabilities and accomplishments of the groups within the Department. In this FY 89/90 Report, we have chosen instead to present twelve of our projects in full-length technical articles. This Overview introduces those articles and highlights other significant research performed during this period.

  7. NSF losing Earth sciences research funds

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    The Earth Sciences Division (EAR) of the National Science Foundation (NSF) faces a diminishing financial base from which to award grants for research, while the proposal pressure increases. Robin Brett, director of the division stated, ‘Now that the Ocean Drilling Division has become a separate entity [within the Foundation] the Division of Earth Sciences has no major facility, and with the exception of COCORP, at $2.8 million per year, we are a small science division, consisting of four programs—geology, geophysics, geochemistry, and petrology.’Brett noted, however, that the field of earth sciences research, which the NSF attempts to support, has grown rapidly in the past decade. Growth (in terms of people employed in the field) is predicted to increase markedly, as the following quotation from Science and Engineering Education for the 1980s and Beyond (NSF publication, 1980) attests:

  8. Online Analysis Enhances Use of NASA Earth Science Data

    NASA Technical Reports Server (NTRS)

    Acker, James G.; Leptoukh, Gregory

    2007-01-01

    Giovanni, the Goddard Earth Sciences Data and Information Services Center (GES DISC) Interactive Online Visualization and Analysis Infrastructure, has provided researchers with advanced capabilities to perform data exploration and analysis with observational data from NASA Earth observation satellites. In the past 5-10 years, examining geophysical events and processes with remote-sensing data required a multistep process of data discovery, data acquisition, data management, and ultimately data analysis. Giovanni accelerates this process by enabling basic visualization and analysis directly on the World Wide Web. In the last two years, Giovanni has added new data acquisition functions and expanded analysis options to increase its usefulness to the Earth science research community.

  9. Final Report DOE Contract No. DE-FG36-04G014294 ICEKAP 2004: A Collaborative Joint Geophysical Imaging Project at Krafla and IDDP P.E. Malin, S.A. Onacha, E. Shalev Division of Earth and Ocean Sciences Nicholas School of the Environment Duke University Durham, NC 27708

    SciTech Connect

    Malin, Peter E.; Shalev, Eylon; Onacha, Stepthen A.

    2006-12-15

    In this final report, we discuss both theoretical and applied research resulting from our DOE project, ICEKAP 2004: A Collaborative Joint Geophysical Imaging Project at Krafla and IDDP. The abstract below begins with a general discussion of the problem we addressed: the location and characterization of “blind” geothermal resources using microearthquake and magnetotelluric measurements. The abstract then describes the scientific results and their application to the Krafla geothermal area in Iceland. The text following this abstract presents the full discussion of this work, in the form of the PhD thesis of Stephen A. Onacha. The work presented here was awarded the “Best Geophysics Paper” at the 2005 Geothermal Resources Council meeting, Reno. This study presents the modeling of buried fault zones using microearthquake and electrical resistivity data based on the assumptions that fluid-filled fractures cause electrical and seismic anisotropy and polarization. In this study, joint imaging of electrical and seismic data is used to characterize the fracture porosity of the fracture zones. P-wave velocity models are generated from resistivity data and used in locating microearthquakes. Fracture porosity controls fluid circulation in the hydrothermal systems and the intersections of fracture zones close to the heat source form important upwelling zones for hydrothermal fluids. High fracture porosity sites occur along fault terminations, fault-intersection areas and fault traces. Hydrothermal fault zone imaging using resistivity and microearthquake data combines high-resolution multi-station seismic and electromagnetic data to locate rock fractures and the likely presence fluids in high temperature hydrothermal systems. The depths and locations of structural features and fracture porosity common in both the MT and MEQ data is incorporated into a joint imaging scheme to constrain resistivity, seismic velocities, and locations of fracture systems. The imaging of the

  10. Summary of the Discussion on the Prediction of Earth Orientation Parameters

    DTIC Science & Technology

    2007-09-01

    SEP 2007 2. REPORT TYPE 3. DATES COVERED 00-00-2007 to 00-00-2007 4. TITLE AND SUBTITLE Summary of the Discussion on the Prediction of Earth ...SUMMARY OF THE DISCUSSION ON THE PREDICTION OF EARTH ORIENTATION PARAMETERS W. WOODEN USNO Naval Observatory 3450 Massachusetts Avenue, N. W...Geophysical In- terpretation of Earth Orientation Parameters.” The panel, drawn from the membership of the IERS Working Group on Prediction (WGP

  11. Inverse Retrospective Problem of Thermal Evolution of the Earth Interior

    NASA Astrophysics Data System (ADS)

    Ismail-Zadeh, A.

    2009-04-01

    I consider an inverse (time-reverse) problem of thermal evolution of a viscous inhomogeneous incompressible heat-conducting fluid describing dynamics of the Earth's mantle. Present observations of geophysical fields (temperature, velocity) are incorporated in a three-dimensional dynamic model to determine the initial conditions of the fields. I present and compare numerical techniques for assimilation of geophysical and geodetical data into the geological past: backward advection, variational (adjoint), and quasi-reversibility methods. The methods are applied to restore the evolution of the mantle structures such as rising plumes and descending lithospheric plates.

  12. Functional eye movement disorders.

    PubMed

    Kaski, D; Bronstein, A M

    2017-01-01

    Functional (psychogenic) eye movement disorders are perhaps less established in the medical literature than other types of functional movement disorders. Patients may present with ocular symptoms (e.g., blurred vision or oscillopsia) or functional eye movements may be identified during the formal examination of the eyes in patients with other functional disorders. Convergence spasm is the most common functional eye movement disorder, but functional gaze limitation, functional eye oscillations (also termed "voluntary nystagmus"), and functional convergence paralysis may be underreported. This chapter reviews the different types of functional eye movement abnormalities and provides a practical framework for their diagnosis and management.

  13. Wavelet correlations to reveal multiscale coupling in geophysical systems

    NASA Astrophysics Data System (ADS)

    Casagrande, Erik; Mueller, Brigitte; Miralles, Diego G.; Entekhabi, Dara; Molini, Annalisa

    2015-08-01

    The interactions between climate and the environment are highly complex. Due to this complexity, process-based models are often preferred to estimate the net magnitude and directionality of interactions in the Earth system. However, these models are based on simplifications of our understanding of nature and thus are unavoidably imperfect. Conversely, observation-based data of climatic and environmental variables are becoming increasingly accessible over global scales due to the progress of spaceborne sensing technologies and data-assimilation techniques. Albeit uncertain, these data enable the possibility to start unraveling complex multivariable, multiscale relationships if the appropriate statistical methods are applied. Here we investigate the potential of the wavelet cross-correlation method as a tool for identifying time/frequency-dependent interactions, feedback, and regime shifts in geophysical systems. The ability of wavelet cross-correlation to resolve the fast and slow components of coupled systems is tested on synthetic data of known directionality and then applied to observations to study one of the most critical interactions between land and atmosphere: the coupling between soil moisture and near-ground air temperature. Results show that our method is able to capture the dynamics of the soil moisture-temperature coupling over a wide range of temporal scales (from days to several months) and climatic regimes (from wet to dry) and consistently identify the magnitude and directionality of the coupling. Consequently, wavelet cross-correlations are presented as a promising tool for the study of multiscale interactions, with the potential of being extended to the analysis of causal relationships in the Earth system.

  14. A Geophysical Study of Fissures in Pahrump, Nevada

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

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

  15. Annual report of the Mizusawa Astrogeodynamics Observatory. Time Service and geophysical observations for the year 1992.

    NASA Astrophysics Data System (ADS)

    Manabe, S.

    This annual report for the year 1992 consists of two parts. The first part shows the results of the time services, i.e., time and latitude observations with the PZT, comparison of UTC(NAOM) with the Loran C and GPS (Global Positioning System), and comparison of the atomic clocks at the Mizusawa Astrogeodynamics Observatory. The PZT closed its activity in April 1993. Hence, the results in 1993 are also included in this volume. The second part shows the results of the geophysical observations at the Esashi Earth Tides Station and the absolute gravity measurements.

  16. Geophysical Information from Advanced Sounder Infrared Spectral Radiance

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Zhou, Daniel K.; Liu, Xu; Smith, William L.

    2012-01-01

    Advanced satellite sensors are tasked with improving global observations of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Satisfying this type of improvement for inferred geophysical information from these observations requires optimal usage of data from current systems as well as enhancements to future sensors. This presentation addresses the information content present in infrared spectral radiance from advanced atmospheric sounders with an emphasis on knowledge of thermodynamic state and trace species. Results of trade-off studies conducted to evaluate the impact of spectral resolution, spectral coverage, instrument noise, and a priori knowledge on remote sensing system information content will be discussed. A focus is placed on information achievable from the Atmospheric InfraRed Sounder (AIRS) on the NASA EOS Aqua satellite in orbit since 2002, the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A since 2006, and the Cross-track Infrared Sounder (CrIS) instrument aboard the NPP and JPSS series of satellites which began 28 October 2011.

  17. Global Bathymetric Prediction For Ocean Modeling and Marine Geophysics

    NASA Technical Reports Server (NTRS)

    Sandwell, David T.; Smith, Walter H. F.; Sichoix, Lydie; Frey, Herbert V. (Technical Monitor)

    2001-01-01

    We proposed to construct a complete bathymetric map of the oceans at a 3-10 km resolution by combining all of the available depth soundings collected over the past 30 years with high resolution marine gravity information provided by the Geosat, ERS-1/2, and Topex/Poseidon altimeters. Detailed bathymetry is essential for understanding physical oceanography and marine geophysics. Currents and tides are controlled by the overall shapes of the ocean basins as well as the smaller sharp ocean ridges and seamounts. Because erosion rates are low in the deep oceans, detailed bathymetry reveals the mantle convection patterns, the plate boundaries, the cooling/subsidence of the oceanic lithosphere, the oceanic plateaus, and the distribution of off-ridge volcanoes. We proposed to: (1) Accumulate all available depth soundings collected over the past 30 years; (2) Use the short wavelength (< 160 km) satellite gravity information to interpolate between sparse ship soundings; (3) Improve the resolution of the marine gravity field using enhanced estimates along repeat altimeter profiles together with the dense altimeter measurements; (4) Refine/improve bathymetric predictions using the improved resolution gravity field and also by investigating computer-intensive methods for bathymetric prediction such as inverse theory; and (5) Produce a 'Globe of the Earth' similar to the globe of Venus prepared by the NASA Magellan investigation. This will also include the best available digital land data.

  18. REVIEWS OF TOPICAL PROBLEMS: Free convection in geophysical processes

    NASA Astrophysics Data System (ADS)

    Alekseev, V. V.; Gusev, A. M.

    1983-10-01

    A highly significant geophysical process, free convection, is examined. Thermal convection often controls the dynamical behavior in several of the earth's envelopes: the atmosphere, ocean, and mantle. Section 2 sets forth the thermohydrodynamic equations that describe convection in a compressible or incompressible fluid, thermochemical convection, and convection in the presence of thermal diffusion. Section 3 reviews the mechanisms for the origin of the global atmospheric and oceanic circulation. Interlatitudinal convection and jet streams are discussed, as well as monsoon circulation and the mean meridional circulation of ocean waters due to the temperature and salinity gradients. Also described are the hypotheses for convective motion in the mantle and the thermal-wave (moving flame) mechanism for inducing global circulation (the atmospheres of Venus and Mars provide illustrations). Eddy formation by convection in a centrifugal force field is considered. Section 4 deals with medium- and small-scale convective processes, including hurricane systems with phase transitions, cellular cloud structure, and convection penetrating into the ocean, with its stepped vertical temperature and salinity microstructure. Self-oscillatory processes involving convection in fresh-water basins are discussed, including effects due to the anomalous (p,T) relation for water.

  19. EarthChem and SESAR: Data Resources and Interoperability for EarthScope Cyberinfrastructure

    NASA Astrophysics Data System (ADS)

    Lehnert, K. A.; Walker, D.; Block, K.; Vinay, S.; Ash, J.

    2008-12-01

    Data management within the EarthScope Cyberinfrastructure needs to pursue two goals in order to advance and maximize the broad scientific application and impact of the large volumes of observational data acquired by EarthScope facilities: (a) to provide access to all data acquired by EarthScope facilities, and to promote their use by broad audiences, and (b) to facilitate discovery of, access to, and integration of multi-disciplinary data sets that complement EarthScope data in support of EarthScope science. EarthChem and SESAR, the System for Earth Sample Registration, are two projects within the Geoinformatics for Geochemistry program that offer resources for EarthScope CI. EarthChem operates a data portal that currently provides access to >13 million analytical values for >600,000 samples, more than half of which are from North America, including data from the USGS and all data from the NAVDAT database, a web-accessible repository for age, chemical and isotopic data from Mesozoic and younger igneous rocks in western North America. The new EarthChem GEOCHRON database will house data collected in association with GeoEarthScope, storing and serving geochronological data submitted by participating facilities. The EarthChem Deep Lithosphere Dataset is a compilation of petrological data for mantle xenoliths, initiated in collaboration with GeoFrame to complement geophysical endeavors within EarthScope science. The EarthChem Geochemical Resource Library provides a home for geochemical and petrological data products and data sets. Parts of the digital data in EarthScope CI refer to physical samples such as drill cores, igneous rocks, or water and gas samples, collected, for example, by SAFOD or by EarthScope science projects and acquired through lab-based analysis. Management of sample-based data requires the use of global unique identifiers for samples, so that distributed data for individual samples generated in different labs and published in different papers can be

  20. Space sickness on earth

    NASA Astrophysics Data System (ADS)

    Nooij, S. A. E.; Bos, J. E.; Groen, E. L.; Bles, W.; Ockels, W. J.

    2007-09-01

    During the first days in space, i.e., after a transition from 1G to 0G, more than 50% of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find.

  1. Cosmic Rays at Earth

    NASA Astrophysics Data System (ADS)

    Grieder, P. K. F.

    In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery. Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological

  2. Applications of geophysical methods to volcano monitoring

    USGS Publications Warehouse

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

    2006-01-01

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

  3. Orientation and movement in unusual force environments

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.

    1993-01-01

    A manned space mission to Mars might take as long as 1 year each way. Consequently, artificial gravity is being considered as a way of preventing the debilitating effects of long-duration exposure to microgravity on the human body. The present article discusses some of the problems associated with adapting to the rotation levels that might be used to generate artificial gravity. It also describes how exposure to background-force levels greater or less than the 1-G force of Earth gravity affects orientation and movement control. The primary emphasis of the article is that human movement and orientation control are dynamically adapted to the 1-G force background of Earth and that accommodation to altered force levels or to rotating environments requires a wide range of adaptive changes.

  4. Field studies in geophysical diffraction tomography

    SciTech Connect

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

    1992-01-01

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

  5. Field studies in geophysical diffraction tomography

    SciTech Connect

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

    1992-07-01

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

  6. Lake Ontario geological and geophysical data sources

    USGS Publications Warehouse

    Hutchinson, Deborah R.; Wold, Richard J.

    1979-01-01

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

  7. Geophysical investigation at Fort Detrick Maryland. Final report

    SciTech Connect

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

    1993-07-01

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

  8. A fractured rock geophysical toolbox method selection tool

    USGS Publications Warehouse

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

    2016-01-01

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

  9. Design and Performance Optimization of GeoFEST for Adaptive Geophysical Modeling on High Performance Computers

    NASA Astrophysics Data System (ADS)

    Norton, C. D.; Parker, J. W.; Lyzenga, G. A.; Glasscoe, M. T.; Donnellan, A.

    2006-12-01

    The Geophysical Finite Element Simulation Tool (GeoFEST) and the PYRAMID parallel adaptive mesh refinement library have been integrated to provide high performance and high resolution modeling of 3D Earth crustal deformation under tectonic loading associated with the Earthquake cycle. This includes co-seismic and post-seismic modeling capabilities as well as other problems of geophysical interest. The use of the PYRAMID AMR library has allowed simulations of tens of millions of elements on various parallel computers where strain energy is applied as the error estimation criterion. This has allowed for improved generation of time-dependent simulations where the computational effort can be localized to geophysical regions of most activity. This talk will address techniques including conversion of the sequential GeoFEST software to a parallel version using PYRAMID, performance optimization and various lessons learned as part of porting such software to various parallel systems including Linux Clusters, SGI Altix systems, and Apple G5 XServe systems. We will also describe how the software has been applied in modeling of post-seismic deformation studies of the Landers and Northridge earthquake events.

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

    USGS Publications Warehouse

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

    2006-01-01

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

  11. Geochemical constraints on Earth's core composition

    NASA Astrophysics Data System (ADS)

    Siebert, Julien

    2016-04-01

    The density of the core as measured from seismic-wave velocities is lower (by 10-15%) than that of pure iron, and therefore the core must also contain some light elements. Geophysical and cosmochemical constraints indicate that obvious candidates for these light elements include silicon, oxygen, and sulfur. These elements have been studied extensively for the past 30 years but a joint solution fulfilling all the requirements imposed by cosmochemistry and geochemistry, seismology, and models of Earth's accretion and core formation is still a highly controversial subject. Here are presented new experimental data in geochemistry used to place constraints on Earth's core composition. Metal-silicate partitioning experiments were performed at pressures and temperatures directly similar to those that prevailed in a deep magma ocean in the early Earth. The results show that core formation can reconcile the observed concentrations of siderophile elements in the silicate mantle with geophysical constraints on light elements in the core. Partitioning results also lead to a core containing less than 1 wt.% of sulfur, inconsistent with a S-rich layer to account for the observed structure of the outer core. Additionally, isotopic fractionations in core formation experiments are presented. This experimental tool merging the fields of experimental petrology and isotope geochemistry represents a promising approach, providing new independent constraints on the nature of light elements in the core.

  12. Geophysical Monitoring of Active Infiltration Experiments for Recharge Estimation: Gains and Pains

    NASA Astrophysics Data System (ADS)

    Noell, U.; Lamparter, A.; Houben, G.; Koeniger, P.; Stoeckl, L.; Guenther, T.

    2014-12-01

    Drinking water supply on the island of Langeoog, North Sea, solely depends on groundwater from a freshwater lens. The correct estimation of the recharge rate is critical for a sustainable use of the resource. Extensive hydrogeological and geophysical studies have revealed differences in groundwater recharge by a factor of two and more between the top of the dunes and the dune valleys. The most convincing proof of these differences in recharge is based on isotope analysis (age dating) but boreholes are scarce and a direct proof of recharge is desired. For this purpose active infiltration experiments are performed and geophysically monitored. Former applications of this method in sand and loess soil gave evidence for the applicability of the geophysical observation when combined with tensiometers installed in situ at depth. These results showed firstly that in sandy soil the water reaches the groundwater table quicker than anticipated due to the water repellent characteristic of the dry sand, inhibiting the lateral spreading of the water. The studies also revealed that in loess preferential flow is initiated by ponding and that sprinkling caused very slow movement of water within the unsaturated zone and the water remained near the surface. On the island of Langeoog field experiments underlined the importance of water repellency on the dune surface, indicating that the rain water runs off superficially into the dune valleys where higher recharge is found. The active infiltration zone of the experiment covers an area of some 7m² and includes steeper parts of the dune. The infiltration will vary depending on rainfall intensity and duration, original water content and vegetation cover. What results can we reliably expect from the active experiment and what additional measurements are required to back up the findings? Results are ambiguous with regard to the quantitative assessment but the processes can be visualized by geophysical monitoring in situ.

  13. Geologic and Geophysical Framework of the Santa Rosa 7.5' Quadrangle, Sonoma County, California

    USGS Publications Warehouse

    McLaughlin, R.J.; Langenheim, V.E.; Sarna-Wojcicki, A. M.; Fleck, R.J.; McPhee, D.K.; Roberts, C.W.; McCabe, C.A.; Wan, Elmira

    2008-01-01

    The geologic and geophysical maps of Santa Rosa 7.5? quadrangle and accompanying structure sections portray the sedimentary and volcanic stratigraphy and crustal structure of the Santa Rosa 7.5? quadrangle and provide a context for interpreting the evolution of volcanism and active faulting in this region. The quadrangle is located in the California Coast Ranges north of San Francisco Bay and is traversed by the active Rodgers Creek, Healdsburg and Maacama Fault Zones. The geologic and geophysical data presented in this report, are substantial improvements over previous geologic and geophysical maps of the Santa Rosa area, allowing us to address important geologic issues. First, the geologic mapping is integrated with gravity and magnetic data, allowing us to depict the thicknesses of Cenozoic deposits, the depth and configuration of the Mesozoic basement surface, and the geometry of fault structures beneath this region to depths of several kilometers. This information has important implications for constraining the geometries of major active faults and for understanding and predicting the distribution and intensity of damage from ground shaking during earthquakes. Secondly, the geologic map and the accompanying description of the area describe in detail the distribution, geometry and complexity of faulting associated with the Rodgers Creek, Healdsburg and Bennett Valley Fault Zones and associated faults in the Santa Rosa quadrangle. The timing of fault movements is constrained by new 40Ar/39Ar ages and tephrochronologic correlations. These new data provide a better understanding of the stratigraphy of the extensive sedimentary and volcanic cover in the area and, in particular, clarify the formational affinities of Pliocene and Pleistocene nonmarine sedimentary units in the map area. Thirdly, the geophysics, particularly gravity data, indicate the locations of thick sections of sedimentary and volcanic fill within ground water basins of the Santa Rosa plain and

  14. Geophysical controls of chemical disequilibria in Europa

    NASA Astrophysics Data System (ADS)

    Vance, S. D.; Hand, K. P.; Pappalardo, R. T.

    2016-05-01

    The ocean in Jupiter's moon Europa may have redox balance similar to Earth's. On Earth, low-temperature hydration of crustal olivine produces substantial hydrogen, comparable to any potential flux from volcanic activity. Here we compare hydrogen and oxygen production rates of the Earth system with fluxes to Europa's ocean. Even without volcanic hydrothermal activity, water-rock alteration in Europa causes hydrogen fluxes 10 times smaller than Earth's. Europa's ocean may have become reducing for a brief epoch, for example, after a thermal-orbital resonance ˜2 Gyr after accretion. Estimated oxidant flux to Europa's ocean is comparable to estimated hydrogen fluxes. Europa's ice delivers oxidants to its ocean at the upper end of these estimates if its ice is geologically active, as evidence of geologic activity and subduction implies.

  15. Congenital mirror movements.

    PubMed Central

    Schott, G D; Wyke, M A

    1981-01-01

    In this report are described seven patients assessed clinically and neuropsychologically in whom mirror movements affecting predominantly the hands occurred as a congenital disorder. These mirror movements, representing a specific type of abnormal synkinesia, may arise as a hereditary condition, in the presence of a recognisable underlying neurological abnormality, and sporadically, and the seven patients provide more or less satisfactory examples of each of these three groups. Despite the apparent uniformity of the disorder, the heterogeneity and variability may be marked, examples in some of our patients including the pronounced increase in tone that developed with arm movement, and the capacity for modulation of the associated movement by alteration of neck position and bio-feedback. Various possible mechanisms are considered; these include impaired cerebral inhibition of unwanted movements, and functioning of abnormal motor pathways. Emphasis has been placed on the putative role of the direct, crossed corticomotoneurone pathways and on the unilateral and bilateral cerebral events that precede movement. PMID:7288446

  16. [Sleep related movement disorders].

    PubMed

    Suzuki, Keisuke; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Hirata, Koichi

    2015-06-01

    Sleep related movement disorders (SRMD) are characterized by simple, stereotyped movements occur during sleep, with the exception of restless legs syndrome (RLS). RLS has the following essential features; an urge to move the legs usually accompanied by uncomfortable sensation in the legs, improvement of symptoms after movement (non-stereotypical movements, such as walking and stretching, to reduce symptoms), and symptoms occur or worsen during periods of rest and in the evening and night. However, RLS is closely associated with periodic limb movement, which shows typical stererotyped limb movements. In the International Classification of Sleep Disorders, 3rd edition, sleep disturbances or daytime symptoms are prerequiste for a diagnosis of SRMD. We here review diagnosis and treatment of SRMD.

  17. Geophysical Studies Related to Geodetic Reference Frames

    DTIC Science & Technology

    1990-02-09

    Chandler wobble to estimate anelasticity at the 14 month wob- ble period. The 18.6 year solid-Earth and ocean tides, related to the precession of the...should continue to improve as more satellite data are acquired. The Chandler wobble constraint on anelasticity [see, for example, Smith and Dahlen...coincidental is the existence of a normal mode of the earth (the Chandler wobble ) near one of the peaks in the local pressure spectrum, and the fact that the

  18. Geophysical Monitoring of Soil Stabilization Processes

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  19. New perspectives on superparameterization for geophysical turbulence

    NASA Astrophysics Data System (ADS)

    Majda, Andrew J.; Grooms, Ian

    2014-08-01

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

  20. Geophysical mapping of palsa peatland permafrost

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  1. Geophysical mapping of palsa peatland permafrost

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  2. Diversity of threshold phenomena in geophysical media

    NASA Astrophysics Data System (ADS)

    Guglielmi, A. V.

    2017-01-01

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

  3. New perspectives on superparameterization for geophysical turbulence

    SciTech Connect

    Majda, Andrew J.; Grooms, Ian

    2014-08-15

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

  4. Geophysical Limitations on the Habitable Zone

    NASA Astrophysics Data System (ADS)

    Noack, L.; Van Hoolst, T.

    2015-10-01

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

  5. Field implementation of geophysical diffraction tomography

    SciTech Connect

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

    1984-01-01

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

  6. Integrated Software Framework for Geophysical Data Processing

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  7. Minimax approach to inverse problems of geophysics

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  8. World Data Center / National Geophysical Data Center's Tsunami Data Archive

    NASA Astrophysics Data System (ADS)

    Dunbar, P. K.; Brantley, K.; Stroker, K.

    2005-12-01

    The WDC for Solid Earth Geophysics (including tsunamis) is operated by NOAA's National Geophysical Data Center (NGDC). NGDC is one of three environmental data centers within the National Environmental Satellite, Data and Information Service (NESDIS). Operating both World and National Data Centers, WDC/NGDC is now providing the long-term archive, data management, and access to national and global tsunami data for research and mitigation of tsunami hazards. Archive responsibilities include the global historic tsunami event and runup database, the bottom pressure recorder data, and access to event-specific tide-gauge data, as well as other related hazards and bathymetric data and information. The WDC/NGDC Worldwide Tsunami Database includes more than 2,400 events since 2,000 BC and more than 7,200 locations where tsunamis were observed. Times of generating earthquakes, tsunami arrival times, travel times, first motion of the wave, and wave periods are included in the database. The WDC/NGDC Worldwide Significant Earthquake Database includes information for more than 6,600 destructive earthquakes from 2,000 B.C. to the present. In the 1980s, NOAA's Pacific Marine Environmental Laboratory (PMEL) developed deep ocean tsunameters for the early detection, measurement, and real-time reporting of tsunamis in the open ocean. The tsunameters were developed by PMEL's Project DART (Deep-ocean Assessment and Reporting of Tsunamis). A DART system consists of a seafloor bottom pressure recording (BPR) system capable of detecting tsunamis as small as 1 cm, and a moored surface buoy for real-time communications. An acoustic link is used to transmit data from the BPR on the seafloor to the surface buoy. The data are then relayed via a GOES satellite link to ground stations for immediate dissemination to NOAA's Tsunami Warning Centers and PMEL. These systems were deployed near regions with a history of tsunami generation, to ensure measurement of the waves as they propagate towards

  9. Adaptive mesh refinement and adjoint methods in geophysics simulations

    NASA Astrophysics Data System (ADS)

    Burstedde, Carsten

    2013-04-01

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

  10. MOVEMENT IN THE CYANOPHYCEAE

    PubMed Central

    Burkholder, Paul R.

    1933-01-01

    The effect of pH upon the velocity of translatory movement of Oscillatoria formosa Bory in inorganic culture solutions was determined. Unhindered movement occurred in the range of about pH 6.4 to 9.5. Above and below these limits inhibition was marked. In the unfavorable acid and alkaline ranges inhibition was progressive with exposure time; in the favorable range continuous movement was maintained for 24 hours. PMID:19872745

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

    NASA Astrophysics Data System (ADS)

    McAdoo, B. G.

    2003-12-01

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

  12. Asymmetric Earth

    NASA Astrophysics Data System (ADS)

    Doglioni, Carlo; Carminati, Eugenio; Crespi, Mattia; Cuffaro, Marco; Ismail-Zadeh, Alik; Levshin, Anatoli; Panza, Giuliano F.; Riguzzi, Federica

    2010-05-01

    The net rotation, or so-called W-ward drift of the lithosphere, implies a decoupling of the plates relative to the underlying asthenosphere, and a relative "E-ward" mantle flow. This polarized flow can account for a number of asymmetries. When comparing the W-directed versus the E- to NE-directed subduction zones, as a general observation, they have the subduction hinge diverging versus converging relative to the upper plate; low versus high topography and structural elevation respectively; deep versus shallow trenches and foreland basins; shallow versus deep decollement; low versus high basement involvement; high versus low heat flow and gravity anomaly; shallow versus deep asthenosphere; etc. The western limbs of rift zones show S-waves faster in the lithosphere and slower in the asthenosphere with respect to the eastern limb. The asymmetry can be recognized when moving along the "tectonic equator", which describes the fastest flow of plates relative to the mantle, and it undulates relative to the geographic equator. In our reconstructions, the best fit for the tectonic equator has a pole of rotation at latitude -56.4° and longitude 136.7°, with an angular velocity of 1.2036°/Ma. Shear-wave splitting alignments tend to parallel the tectonic flow, apart along the subduction zones where they become orthogonal, as a flow encountering an obstacle. The tectonic equator lies close to the revolution plane of the Moon about the Earth. All these data and interpretations point for an asymmetric Earth, whose nature appears to be related to the rotation and its tidal despinning, combined with the thermal cooling of the planet. However, this model has been questioned on the basis of the high viscosity so far inferred in the asthenosphere. Preliminary modelling shows that the tidal oscillation can generate gravitational wave propagation in the lithosphere, and the wave velocity can increase with the decrease of the asthenospheric viscosity.

  13. Tides and lake-level variations in the great Patagonian lakes: Observations, modelling and geophysical implications.

    NASA Astrophysics Data System (ADS)

    Marderwald, Eric; Richter, Andreas; Horwath, Martin; Hormaechea, Jose Luis; Groh, Andreas

    2016-04-01

    In Patagonia, the glacial-isostatic adjustment (GIA) to past ice-mass changes (Ivins & James 2004; Klemann et al. 2007) is of particular interest in the context of the determination of the complex regional rheology related to plate subduction in a triple-junction constellation. To further complicate the situation, GIA is overlaid with load deformation not only due to present ice mass changes but also due to water-level changes in the lakes surrounding the icefields and the ocean surrounding Patagonia. These elastic deformations affect the determination of glacial-isostatic uplift rates from GPS observations (Dietrich et al. 2010; Lange et al. 2014). Observations of lake tides and their comparison with the theoretical tidal signal have been used previously to validate predictions of ocean tidal loading and have revealed regional deviations from conventional global elastic earth models (Richter et al. 2009). In this work we investigate the tides and lake-level variations in Lago Argentino, Lago Viedma, Lago San Martín/O'Higgins and Lago Buenos Aires/General Carrera. This allows us to test, among other things, the validity of tidal loading models. We present pressure tide-gauge records from two sites in Lago Argentino extending over 2.5 years (Richter et al. 2015). These observations are complemented by lake-level records provided by the Argentine National Hydrometeorological Network. Based on these lake-level time series the principal processes affecting the lake level are identified and quantified. Lake-level changes reflecting variations in lake volume are dominated by a seasonal cycle exceeding 1 m in amplitude. Lake-volume changes occur in addition with a daily period in response to melt water influx from surrounding glaciers. In Lago Argentino sporadic lake-volume jumps are caused by bursting of the ice dam of Perito Moreno glacier. Water movements in these lakes are dominated by surface seiches reaching 20 cm in amplitude. A harmonic tidal analysis of the lake

  14. The mathematics of movement

    USGS Publications Warehouse

    Johnson, D.H.

    1999-01-01

    Review of: Quantitative Analysis of Movement: Measuring and Modeling Population Redistribution in Animals and Plants. Peter Turchin. 1998. Sinauer Associates, Sunderland, MA. 306 pages. $38.95 (paper).

  15. Thermodynamics of the Earth

    NASA Astrophysics Data System (ADS)

    Stacey, Frank D.

    2010-04-01

    Applications of elementary thermodynamic principles to the dynamics of the Earth lead to robust, quantitative conclusions about the tectonic effects that arise from convection. The grand pattern of motion conveys deep heat to the surface, generating mechanical energy with a thermodynamic efficiency corresponding to that of a Carnot engine operating over the adiabatic temperature gradient between the heat source and sink. Referred to the total heat flux derived from the Earth's silicate mantle, the efficiency is 24% and the power generated, 7.7 × 1012 W, causes all the material deformation apparent as plate tectonics and the consequent geological processes. About 3.5% of this is released in seismic zones but little more than 0.2% as seismic waves. Even major earthquakes are only localized hiccups in this motion. Complications that arise from mineral phase transitions can be used to illuminate details of the motion. There are two superimposed patterns of convection, plate subduction and deep mantle plumes, driven by sources of buoyancy, negative and positive respectively, at the top and bottom of the mantle. The patterns of motion are controlled by the viscosity contrasts (>104 : 1) at these boundaries and are self-selected as the least dissipative mechanisms of heat transfer for convection in a body with very strong viscosity variation. Both are subjects of the thermodynamic efficiency argument. Convection also drives the motion in the fluid outer core that generates the geomagnetic field, although in that case there is an important energy contribution by compositional separation, as light solute is rejected by the solidifying inner core and mixed into the outer core, a process referred to as compositional convection. Uncertainty persists over the core energy balance because thermal conduction is a drain on core energy that has been a subject of diverse estimates, with attendant debate over the need for radiogenic heat in the core. The geophysical approach to

  16. Multi-sensor geophysical constraints on crustal melt in the central Andes: the PLUTONS project

    NASA Astrophysics Data System (ADS)

    Pritchard, M. E.; Comeau, M. J.; West, M. E.; Christensen, D. H.; Mcfarlin, H. L.; Farrell, A. K.; Del Potro, R.; Gottsmann, J.; McNutt, S. R.; Michelfelder, G.; Diez, M.; Elliott, J.; Henderson, S. T.; Keyson, L.; Delgado, F.; Unsworth, M. J.

    2015-12-01

    The central Andes is a key global location to quantify storage, transport, and volumes of magma in the Earth's crust as it is home to the world's largest zone of partial melt (the Altiplano-Puna Magma or Mush Body, APMB) as well as the more recently documented Southern Puna Magma Body (SPMB). We describe results from the recently completed international PLUTONS project that focused inter-disciplinary study on two sites of large-scale surface uplift that presumably represent ongoing magmatic intrusions in the mid to upper crust - Uturuncu, Bolivia (in the center of the APMB) and Lazufre on the Chile-Argentina border (on the edge of the SPMB). In particular, a suite of geophysical techniques (seismology, gravity, surface deformation, and electro-magnetic methods) have been used to infer the current subsurface distribution and quantity of partial melts in combination with geochemical and lab studies on samples from the area. Both Uturuncu and Lazufre show separate geophysical anomalies in the upper and mid/lower crust (e.g., low seismic velocity, low resistivity, etc.) indicating multiple distinct reservoirs of magma and/or hydrothermal fluids with different properties. The characteristics of the geophysical anomalies differ somewhat depending on the technique used - reflecting the different sensitivity of each method to subsurface melt of different compositions, connectivity, and volatile content. For example, the depth to the top of the APMB is shallower in a joint ambient noise tomography and receiver function analysis compared to a 3D magnetotelluric inversion. One possibility is that the seismic methods are detecting brines above the APMB that do not have a large electromagnetic signature. Comparison of the geophysical measurements with laboratory experiments at the APMB indicate a minimum of 4-25% melt averaged over the region is needed -- higher melt volumes are permitted by the gravity and MT data and may exist in small regions. However, bulk melt values above

  17. R/V Kilo Moana's New Geophysical Instrumentation, Processing Methods, and Online Data Repository

    NASA Astrophysics Data System (ADS)

    Miller, J. E.; Chandler, M. T.; Taylor, B.; Shor, A.; Ferguson, J. S.; Wessel, P.

    2012-12-01

    In 2012 several upgrades were made to the underway geophysical systems on R/V Kilo Moana, which the University of Hawaii School of Ocean and Earth Science and Technology (SOEST) operates as part of the University-National Oceanographic Laboratory System (UNOLS) fleet. New instrumentation includes a Bell BGM-3 forced feedback-type gravimeter, a Kongsberg EM 122 12-kHz receiver array, and a high resolution 70-100 kHz EM 710 multibeam echo sounder. Multibeam acceptance trials carried out in June by the Multibeam Advisory Committee, Gates Acoustic Services and UH-SOEST found that both sonars are performing within expected levels with ~5x water depth (WD) for the EM 710 system in shallow water and ~19 km swath width at 4,700 m depth (~4x WD) for the EM 122 deep water system. UH-SOEST also took steps this year to fulfill its obligation to make Kilo Moana's geophysical data more accessible to the public. After an audit of Kilo Moana data at SOEST, Lamont's Rolling Deck to Repository (R2R) and the National Geophysical Data Center (NGDC), as of July 2012 all National Science Foundation-funded Kilo Moana multibeam, gravity, magnetics, center beam depth and Acoustic Doppler Current Profiler (ADCP) data have been submitted to R2R and any multibeam data over 2 years old is being transferred to NGDC. Because it had previously been difficult to access some of SOEST's geophysical data, updated data processing routines have been developed for converting raw gravity, magnetics, and centerbeam depth data to NGDC's standard marine data exchange format (MGD77) for archival and dissemination by NGDC. MGD77 files are being generated and inspected using rigorous along-track analytical techniques for ~270 surveys dating from 2002 to the present and are being submitted to NGDC. We are also developing an online data portal to further facilitate access to SOEST data.

  18. National Geological and Geophysical Data Preservation Program: Successes and Lessons Learned

    NASA Astrophysics Data System (ADS)

    Adrian, B. M.

    2014-12-01

    The United States Geological Survey (USGS) is widely recognized in the earth science community as possessing extensive collections of geologic and geophysical materials gathered by its research personnel. Since the USGS was established in 1879, hundreds of thousands of samples have been gathered in collections that range from localized, geographically-based assemblages to ones that are national or international in scope. These materials include, but are not limited to, rock and mineral specimens; fossils; drill cores and cuttings; geochemical standards; and soil, sediment, and geochemical samples. The USGS National Geological and Geophysical Data Preservation Program (NGGDPP) was established with the passage of the Energy Policy Act of 2005. Since its implementation, the USGS NGGDPP has taken an active role in providing opportunities to inventory, archive and preserve geologic and geophysical samples, and to make these samples and ancillary data discoverable on the Internet. Preserving endangered geoscience collections is more cost effective than recollecting this information. Preserving these collections, however, is only one part of the process - there also needs to be a means to facilitate open discovery and access to the physical objects and the ancillary digital records. The NGGDPP has celebrated successes such as the development of the USGS Geologic Collections Management System (GCMS), a master catalog and collections management plan, and the implementation and advancement of the National Digital Catalog, a digital inventory and catalog of geological and geophysical data and collections held by the USGS and State geological surveys. Over this period of time there has been many lessons learned. With the successes and lessons learned, NGGDPP is poised to take on challenges the future may bring.

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

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev

    2010-05-01

    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

  20. Integrating Satellite Gravity Data with Geophysical Data Sets for Crustal Modeling in Africa

    NASA Astrophysics Data System (ADS)

    van der Meijde, M.; Tedla, G. E.

    2006-12-01

    The African continent is one of the least studied areas in the world. Due to local circumstances but also to restricted financial and technical means that can be devoted to science, it is difficult to obtain detailed information on the Earth's structure underneath Africa and to maintain geophysical networks. The map of the Earth's structure of Africa has many spots where the crustal thickness and structure is unknown or only known with very large uncertainties. This results in a limited knowledge on African tectonic processes and their relation with and influences on crustal structures. Knowledge of the crustal structure is important for understanding the past and present tectonics and geodynamic evolution of a region, issues that are crucial to many Earth science studies. The crustal structure is not only of importance for studies of the Earth's deep interior, but also for the development of countries on the African continent. In many developing countries, the unexplored crust still holds a great economical potential. To prospect for resources, underground and surface dynamics must be studied and models developed. A detailed crustal model would also improve the accuracy of determination of regional and local earthquake locations and therefore has an impact on seismic hazard assessment and urban planning. In this study, satellite gravity data will be inverted for determining the crustal thickness in Africa. Because of the high non-uniqueness of gravity data in general and satellite gravity data specifically, a multi-disciplinary joint inversion will be performed. A method will be developed to invert gravity satellite data for crustal structure, including various a priori crustal thickness constraints obtained using different geophysical and geological techniques. The inferred crustal structure will be related to known tectonic processes and the implications for the wider African tectonic framework will be assessed. A detailed elevation model will be derived from

  1. The first Earth Resources Technology Satellite (ERTS-1)

    NASA Technical Reports Server (NTRS)

    Nordberg, W.

    1973-01-01

    The first Earth Resources Technology Satellite (ERTS-1) makes images of the earth's surface in four portions of the electromagnetic spectrum with sufficient spatial resolution and with a minimum of geometric distortions, so that these images may be applied experimentally to the study of geophysical processes relating to earth resources, to the exploration and conservation of these resources, and to the assessments of environmental stresses. During the first six months of operation, ERTS-1 has imaged 6.5 million square kilometers of the earth's surface every day, covering most major land masses and coastal zones as well as both polar regions of this planet. These images as well as the results of their analyses are available to all people throughout the world. Scientific investigators of all countries have been invited to participate in the utilization of ERTS-1 observations. Many of them have already demonstrated the great efficiency, economy, and reliability of making earth surveys from space.

  2. Earth physics and phase transformations program: A concept and proposal

    NASA Technical Reports Server (NTRS)

    Bonavito, N. L.; Tanaka, T.

    1971-01-01

    A program to study the geophysical characteristics of the earth is presented as an integration of the different disciplines that constitute the earth sciences, through the foundation of a generalized geodynamic theory of earth physics. A program is considered for defining the physical constants of the earth's material which parametrize the hydrodynamic equation in the microscopic solid state behavior of the crystals of the lithosphere. In addition, in order to lay the foundation for a generalized theory in earth physics, specific research areas are considered, such as the nature of the kinetics of the phase transitions in mineral assemblages, the equilibrium thermodynamic properties of crystals which are major constituents of mineral assemblages, and the transport properties of pure crystals which are major constituents of mineral assemblages.

  3. Oddball Earths in Systems with Super-Earths

    NASA Astrophysics Data System (ADS)

    Asphaug, Erik

    2009-09-01

    During terrestrial planet formation most of the colliding matter comes late, in the form of similar-sized planetary bodies colliding at velocities ranging from 1 to a few times their mutual escape velocity (e.g. Wetherill 1985). I consider an edge effect under these conditions, where the next-largest bodies in a hierarchically accreting population (e.g. Earths) grow increasingly exotic as they survive non-accretionary collisions onto the largest bodies (e.g. super-Earths). Collisions between bodies within a factor of several in size, at around v_esc, are extended-source phenomena where the contact timescale equals the gravity timescale, and where for most geometries most of the colliding matter does not intersect. This sets similar-sized collisions, of which the giant impact formation of the Moon may be an example, far apart from point-source cratering impacts. It has been found and confirmed that in similar-sized collisions, hit-and-run is a more common outcome than efficient accretion. If the largest terrestrial planets grow by feeding on the next-largest planets, and if they eventually accrete most of these next-largest planets, then the surviving (unaccreted) next-largest planets are each likely to be survivors of one or more hit-and-run collisions. These events can cause the loss of atmospheres, oceans, crusts and outer mantles, and lead to exotic pressure-release petrology and degassing. This conclusion appears to be relatively scale invariant, provided the random velocities scale to v_esc, supporting the following corollary for solar systems with Super-Earths: If Earth-massed planets roamed among super-Earths, and survive as bounced-off unaccreted remnants from late stage accretion, then Earth-mass worlds will be as stunningly diverse in these solar systems, as the asteroids and smallest planets are (Moon, Mercury, Mars) in our own system, and may be devoid of atmospheres and oceans. Supported by the NASA Planetary Geology and Geophysics Program and the NASA

  4. Designing Preschool Movement Programs.

    ERIC Educational Resources Information Center

    Sanders, Stephen W.

    This guide contains developmentally appropriate movement activities designed to help teachers of children ages 3 through 5 plan and administer a successful movement education program. The book is organized into three parts. The first part presents a model upon which teachers can base their selection of physical activities for children, addresses…

  5. Randomness Of Amoeba Movements

    NASA Astrophysics Data System (ADS)

    Hashiguchi, S.; Khadijah, Siti; Kuwajima, T.; Ohki, M.; Tacano, M.; Sikula, J.

    2005-11-01

    Movements of amoebas were automatically traced using the difference between two successive frames of the microscopic movie. It was observed that the movements were almost random in that the directions and the magnitudes of the successive two steps are not correlated, and that the distance from the origin was proportional to the square root of the step number.

  6. National CARES Mentoring Movement

    ERIC Educational Resources Information Center

    Mitchell, Martin L.

    2013-01-01

    Harsh and cruel experiences have led many of our young to believe that they are alone in the world and that no one cares. In this article, Martin L Mitchell introduces us to the "National CARES Mentoring Movement" founded by Susan L.Taylor. This movement provides young people with role models who help shape their positive development.…

  7. [Dance/Movement Therapy.

    ERIC Educational Resources Information Center

    Fenichel, Emily, Ed.

    1994-01-01

    This newsletter theme issue focuses on dance, play, and movement therapy for infants and toddlers with disabilities. Individual articles are: "Join My Dance: The Unique Movement Style of Each Infant and Toddler Can Invite Communication, Expression and Intervention" (Suzi Tortora); "Dynamic Play Therapy: An Integrated Expressive Arts Approach to…

  8. 85 Engaging Movement Activities.

    ERIC Educational Resources Information Center

    Weikart, Phyllis S.; Carlton, Elizabeth B.

    This book presents activities to keep K-6 students moving in a variety of ways as they learn. The movement experiences are planned around key curriculum concepts in movement and music as well as in academic curriculum areas. The experiences develop students' basic timing, language abilities, vocabulary, concentration, planning skills, and…

  9. Research for a Movement

    ERIC Educational Resources Information Center

    Litchfield, Randy G.

    2006-01-01

    This article discusses the new era of the Religious Education Association (REA) and how it may be seen to function as a "movement" with purposes, scope, and connectivity that bring together diverse groups. The author contends that religious education as a movement needs: (1) Research that describes patterns and uniquenesses in the religious…

  10. Earth Science Education in Zimbabwe

    NASA Astrophysics Data System (ADS)

    Walsh, Kevin L.

    1999-05-01

    Zimbabwe is a mineral-rich country with a long history of Earth Science Education. The establishment of a University Geology Department in 1960 allowed the country to produce its own earth science graduates. These graduates are readily absorbed by the mining industry and few are without work. Demand for places at the University is high and entry standards reflect this. Students enter the University after GCE A levels in three science subjects and most go on to graduate. Degree programmes include B.Sc. General in Geology (plus another science), B.Sc. Honours in Geology and M.Sc. in Exploration Geology and in Geophysics. The undergraduate curriculum is broad-based and increasingly vocationally orientated. A well-equipped building caters for relatively large student numbers and also houses analytical facilities used for research and teaching. Computers are used in teaching from the first year onwards. Staff are on average poorly qualified compared to other universities, but there is an impressive research element. The Department has good links with many overseas universities and external funding agencies play a strong supporting role. That said, financial constraints remain the greatest barrier to future development, although increasing links with the mining industry may cushion this.

  11. Natural hazards activities of the National Geophysical Data Center

    USGS Publications Warehouse

    Lockridge, P.A.

    1985-01-01

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

  12. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  13. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  14. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  15. 43 CFR 3141.2-1 - Geophysical exploration.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  16. Introduction to the JEEG Agricultural Geophysics special issue

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Application of geophysical methods to agriculture: An overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  18. GENERAL CONSIDERATIONS FOR GEOPHYSICAL METHODS APPLIED TO AGRICULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Geophysical review of Trans-Pecos area of west Texas

    SciTech Connect

    Addy, S.K.; DeJong, H.W.; Whitney, G.W.; Worthington, R.E.

    1985-02-01

    The Trans-Pecos has intrigued and baffled the oil industry, and all exploratory efforts so far have remained fruitless. Our geophysical findings along with other geologic information allow us to analyze the overall hydrocarbon potential for this area. Gravity and magnetic data were helpful in regional mapping but were unreliable for localized information owing to numerous extrusive and intrusive rocks. Seismic mapping shows many undrilled structures. However, the success ratio for the structures already drilled is disappointing (e.g., on the Diablo platform, out of 22 structural leads, 11 have been drilled and all were dry, and in the Marfa basin 17 out of 41 leads were drilled without success). Results were similar in Salt-Flat graben. Many of these wells had good hydrocarbon shows and almost all yielded fresh water. Tectonically the area has undergone several periods of orogeny, the result of the latest being numerous Basin and Range faults. The area is still seismically active and shows appreciable geodetic movement. It is suggested that the traps were destroyed with subsequent leakage of hydrocarbon and repeated induction of fresh water. Trap destruction is apparently beyond the scope of seismic detection. The Chihuahua trough (US), in spite of many discouraging facts, such as high heat flow, thermal waters, etc, shows some promise because seismic data reveal large thrust anticlines in the lower Paleozoic rocks (approximately 15,000 ft) that are yet to be adequately tested. Other small undamaged stratigraphic traps (reefs, truncations, pinch-outs, etc) are possibly present and could be targets for future exploration.

  20. Volumetric Geophysical Retrievals in Precipitating Cloud Systems

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  1. The geology and geophysics of Mars

    NASA Technical Reports Server (NTRS)

    Saunders, R. S.

    1976-01-01

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

  2. Interplay Between the Equatorial Geophysical Processes

    NASA Astrophysics Data System (ADS)

    Sridharan, R.

    2006-11-01

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

  3. Reconnaissance geophysical study of Diablo Platform, Texas

    SciTech Connect

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

    1988-01-01

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

  4. Geophysics could explain Ancient Maya Myth

    NASA Astrophysics Data System (ADS)

    Bruchez, Margaret Sabom

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

  5. Geophysics Could Explain Ancient Maya Myth

    NASA Astrophysics Data System (ADS)

    Sabom Bruchez, Margaret

    2005-03-01

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

  6. Symmetries in geology and geophysics

    PubMed Central

    Turcotte, Donald L.; Newman, William I.

    1996-01-01

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

  7. Resources for History of Geophysics at AIP

    NASA Astrophysics Data System (ADS)

    Good, G. A.

    2012-12-01

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

  8. Opening doors for geophysics in soil sciences

    NASA Astrophysics Data System (ADS)

    Müller, Martin

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

  9. Software complex for geophysical data visualization

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  10. A Network of Geophysical Observatories for Mars

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  11. Analysis of geophysical measurements and spacecraft interactions

    NASA Astrophysics Data System (ADS)

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

    1993-01-01

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

  12. Applied Geophysics Opportunities in the Petroleum Industry

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  13. Terrestrial hydrological Research and Geophysics: Quo Vadis?

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

  14. The Gaias (Earth Mothers) of the Ecological/Conservation Movements.

    ERIC Educational Resources Information Center

    Bradley, Rosa M.; Biermann, Carol A.

    1999-01-01

    Describes the contributions of women who have served as role models in the fields of ecology and conservation. Women discussed include Ellen Richards, Maria Merian, Jane Colden, Mary Chase, Emma Braun, Ann Morgan, Rachel Carson, Eugenie Clark, Sylvia Earle, Wangari Maathai, Dian Fossey, Birute Galdikas, and Ruth Patrick. Contains 26 references.…

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

    NASA Astrophysics Data System (ADS)

    Synolakis, Costas

    2014-05-01

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

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

    SciTech Connect

    Goldstein, N.E.

    1994-03-01

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

  17. Earth Sciences Division annual report 1990

    SciTech Connect

    1991-06-01

    This Annual Report presents summaries of selected representative research activities grouped according to the principal disciplines of the Earth Sciences Division: Reservoir Engineering and Hydrogeology, Geology and Geochemistry, and Geophysics and Geomechanics. Much of the Division`s research deals with the physical and chemical properties and processes in the earth`s crust, from the partially saturated, low-temperature near-surface environment to the high-temperature environments characteristic of regions where magmatic-hydrothermal processes are active. Strengths in laboratory and field instrumentation, numerical modeling, and in situ measurement allow study of the transport of mass and heat through geologic media -- studies that now include the appropriate chemical reactions and the hydraulic-mechanical complexities of fractured rock systems. Of particular note are three major Division efforts addressing problems in the discovery and recovery of petroleum, the application of isotope geochemistry to the study of geodynamic processes and earth history, and the development of borehole methods for high-resolution imaging of the subsurface using seismic and electromagnetic waves. In 1989 a major DOE-wide effort was launched in the areas of Environmental Restoration and Waste Management. Many of the methods previously developed for and applied to deeper regions of the earth will in the coming years be turned toward process definition and characterization of the very shallow subsurface, where man-induced contaminants now intrude and where remedial action is required.

  18. The Geochemical Earth Reference Model (GERM)

    SciTech Connect

    Staudigel, H.; Albarede, F.; Shaw, H.; McDonough, B.; White, W.

    1996-12-01

    The Geochemical Earth Reference Model (GERM) initiative is a grass- roots effort with the goal of establishing a community consensus on a chemical characterization of the Earth, its major reservoirs, and the fluxes between them. Long term goal of GERM is a chemical reservoir characterization analogous to the geophysical effort of the Preliminary Reference Earth Model (PREM). Chemical fluxes between reservoirs are included into GERM to illuminate the long-term chemical evolution of the Earth and to characterize the Earth as a dynamic chemical system. In turn, these fluxes control geological processes and influence hydrosphere-atmosphere-climate dynamics. While these long-term goals are clearly the focus of GERM, the process of establishing GERM itself is just as important as its ultimate goal. The GERM initiative is developed in an open community discussion on the World Wide Web (GERM home page is at http://www-ep.es.llnl. gov/germ/germ-home.html) that is mediated by a series of editors with responsibilities for distinct reservoirs and fluxes. Beginning with the original workshop in Lyons (March 1996) GERM is continued to be developed on the Internet, punctuated by workshops and special sessions at professional meetings. It is planned to complete the first model by mid-1997, followed by a call for papers for a February 1998 GERM conference in La Jolla, California.

  19. New Earth Science Data and Access Methods

    NASA Technical Reports Server (NTRS)

    Moses, John F.; Weinstein, Beth E.; Farnham, Jennifer

    2004-01-01

    NASA's Earth Science Enterprise, working with its domestic and international partners, provides scientific data and analysis to improve life here on Earth. NASA provides science data products that cover a wide range of physical, geophysical, biochemical and other parameters, as well as services for interdisciplinary Earth science studies. Management and distribution of these products is administered through the Earth Observing System Data and Information System (EOSDIS) Distributed Active Archive Centers (DAACs), which all hold data within a different Earth science discipline. This paper will highlight selected EOS datasets and will focus on how these observations contribute to the improvement of essential services such as weather forecasting, climate prediction, air quality, and agricultural efficiency. Emphasis will be placed on new data products derived from instruments on board Terra, Aqua and ICESat as well as new regional data products and field campaigns. A variety of data tools and services are available to the user community. This paper will introduce primary and specialized DAAC-specific methods for finding, ordering and using these data products. Special sections will focus on orienting users unfamiliar with DAAC resources, HDF-EOS formatted data and the use of desktop research and application tools.

  20. Earth Observation

    NASA Technical Reports Server (NTRS)

    1994-01-01

    For pipeline companies, mapping, facilities inventory, pipe inspections, environmental reporting, etc. is a monumental task. An Automated Mapping/Facilities Management/Geographic Information Systems (AM/FM/GIS) is the solution. However, this is costly and time consuming. James W. Sewall Company, an AM/FM/GIS consulting firm proposed an EOCAP project to Stennis Space Center (SSC) to develop a computerized system for storage and retrieval of digital aerial photography. This would provide its customer, Algonquin Gas Transmission Company, with an accurate inventory of rights-of-way locations and pipeline surroundings. The project took four years to complete and an important byproduct was SSC's Digital Aerial Rights-of-Way Monitoring System (DARMS). DARMS saves substantial time and money. EOCAP enabled Sewall to develop new products and expand its customer base. Algonquin now manages regulatory requirements more efficiently and accurately. EOCAP provides government co-funding to encourage private investment in and broader use of NASA remote sensing technology. Because changes on Earth's surface are accelerating, planners and resource managers must assess the consequences of change as quickly and accurately as possible. Pacific Meridian Resources and NASA's Stennis Space Center (SSC) developed a system for monitoring changes in land cover and use, which incorporated the latest change detection technologies. The goal of this EOCAP project was to tailor existing technologies to a system that could be commercialized. Landsat imagery enabled Pacific Meridian to identify areas that had sustained substantial vegetation loss. The project was successful and Pacific Meridian's annual revenues have substantially increased. EOCAP provides government co-funding to encourage private investment in and broader use of NASA remote sensing technology.

  1. Analysis of the geophysical data using a posteriori algorithms

    NASA Astrophysics Data System (ADS)

    Voskoboynikova, Gyulnara; Khairetdinov, Marat

    2016-04-01

    The problems of monitoring, prediction and prevention of extraordinary natural and technogenic events are priority of modern problems. These events include earthquakes, volcanic eruptions, the lunar-solar tides, landslides, falling celestial bodies, explosions utilized stockpiles of ammunition, numerous quarry explosion in open coal mines, provoking technogenic earthquakes. Monitoring is based on a number of successive stages, which include remote registration of the events responses, measurement of the main parameters as arrival times of seismic waves or the original waveforms. At the final stage the inverse problems associated with determining the geographic location and time of the registration event are solving. Therefore, improving the accuracy of the parameters estimation of the original records in the high noise is an important problem. As is known, the main measurement errors arise due to the influence of external noise, the difference between the real and model structures of the medium, imprecision of the time definition in the events epicenter, the instrumental errors. Therefore, posteriori algorithms more accurate in comparison with known algorithms are proposed and investigated. They are based on a combination of discrete optimization method and fractal approach for joint detection and estimation of the arrival times in the quasi-periodic waveforms sequence in problems of geophysical monitoring with improved accuracy. Existing today, alternative approaches to solving these problems does not provide the given accuracy. The proposed algorithms are considered for the tasks of vibration sounding of the Earth in times of lunar and solar tides, and for the problem of monitoring of the borehole seismic source location in trade drilling.

  2. Scientific Knowledge Discovery in Complex Semantic Networks of Geophysical Systems

    NASA Astrophysics Data System (ADS)

    Fox, P.

    2012-04-01

    The vast majority of explorations of the Earth's systems are limited in their ability to effectively explore the most important (often most difficult) problems because they are forced to interconnect at the data-element, or syntactic, level rather than at a higher scientific, or semantic, level. Recent successes in the application of complex network theory and algorithms to climate data, raise expectations that more general graph-based approaches offer the opportunity for new discoveries. In the past ~ 5 years in the natural sciences there has substantial progress in providing both specialists and non-specialists the ability to describe in machine readable form, geophysical quantities and relations among them in meaningful and natural ways, effectively breaking the prior syntax barrier. The corresponding open-world semantics and reasoning provide higher-level interconnections. That is, semantics provided around the data structures, using semantically-equipped tools, and semantically aware interfaces between science application components allowing for discovery at the knowledge level. More recently, formal semantic approaches to continuous and aggregate physical processes are beginning to show promise and are soon likely to be ready to apply to geoscientific systems. To illustrate these opportunities, this presentation presents two application examples featuring domain vocabulary (ontology) and property relations (named and typed edges in the graphs). First, a climate knowledge discovery pilot encoding and exploration of CMIP5 catalog information with the eventual goal to encode and explore CMIP5 data. Second, a multi-stakeholder knowledge network for integrated assessments in marine ecosystems, where the data is highly inter-disciplinary.

  3. DART: New Research Using Ensemble Data Assimilation in Geophysical Models

    NASA Astrophysics Data System (ADS)

    Anderson, Jeffrey; Raeder, Kevin; Hoar, Tim; Collins, Nancy; Romine, Glen; Barre, Jerome; Gaubert, Benjamin; Arellano, Ave; Wuerth, Stephanie

    2016-04-01

    The Data Assimilation Research Testbed (DART) is a community facility for ensemble data assimilation developed and supported by the National Center for Atmospheric Research. DART provides a comprehensive suite of software, documentation, examples and tutorials that can be used for ensemble data assimilation research, operations, and education. Scientists and software engineers from the Data Assimilation Research Section at NCAR are available to actively support DART users who want to use existing DART products or develop their own new applications. Current DART users range from university professors teaching data assimilation, to individual graduate students working with simple models, through national laboratories doing operational prediction with large state-of-the-art models. DART runs efficiently on many computational platforms ranging from laptops through thousands of cores on the newest supercomputers. This poster focuses on several recent research activities using DART with geophysical models: 1). Using CAM/DART to understand whether OCO-2 Total Precipitable Water observations can be useful in numerical weather prediction. 2). Impacts of the synergistic use of Infra-red CO retrievals (MOPITT, IASI) in CAMCHEM/DART assimilations. 3). Assimilation and Analysis of Observations of Amazonian Biomass Burning Emissions by MOPITT (aerosol optical depth), MODIS (carbon monoxide) and MISR (plume height). 4). Long term evaluation of the chemical response of MOPITT-CO assimilation in CAM-CHEM/DART OSSEs for satellite planning and emission inversion capabilities. 5). Improved forward observation operators for land models that have multiple land use/land cover segments in a single grid cell, enabling studies of the inherent variability in a single gridcell. Future enhancements are also discussed: 1). The CICE component of the Community Earth System Model will be added to the existing suite of components, which can be used for data assimilation. 2). Fully coupled

  4. Surface Packages for Geophysical Exploration of Small Bodies

    NASA Astrophysics Data System (ADS)

    Scheeres, D. J.

    2015-12-01

    The geophysical exploration of small rubble pile bodies is fundamentally important for understanding the mechanics of gravitationally bound aggregates. The mechanical and geotechnical properties of these bodies are not understood from an experimental perspective, and have only been studied theoretically and using numerical simulations. To carry out experiments in this environment requires the development and deployment of surface packages to the body surface to enable physical interactions and measurements. This talk will discuss how such experiments can be developed and used in the small body environment. It will particularly focuse on one approach that uses a combination of surface seismic sources and probes to measure the seismic properties of a rubble pile. The small body dynamical environment is particularly well suited for the deployment of such surface packages for exploration and scientific measurement purposes. This is mainly due to their meager gravity fields, which allow the delivery of complex instruments to the surface with impact speeds that are at most a meter per second — equivalent to dropping an object from less than a 5 cm height on Earth. Despite this seeming advantage, the delivery and mobility of such packages on the surface of a small body remains a challenging endeavor, and to date the delivery of surface packages to small bodies has had a mixed success rate. Issues that must be accounted for include the delivery trajectories for probes to the surface, motion on the surface of a small body, and interactions between a probe and a small body surface. Studies of all of these issues both theoretically and experimentally will be presented, along with proposed applications to achieve scientific goals on the surfaces of small bodies.

  5. Asymmetric effects on Earth's polar motion

    NASA Astrophysics Data System (ADS)

    Bizouard, Christian; Zotov, Leonid

    2013-06-01

    Differential equations ruling the Earth's polar motion are slightly asymmetric with respect to the pole coordinates. This is not only associated with the lack of axial symmetry around the Earth figure axis (triaxiality) but also with the longitude dependency of the pole tide (the main contribution). We propose a consistent handling of both asymmetric contributions, formulating a unique equation in the complex equatorial plane, of which we derive a general solution. Difference with respect to the usual symmetric solution is discussed and found significant in light of the present accuracy of the observed pole coordinates. For the same geophysical excitation, the prograde Chandler wobble is accompanied by a retrograde component up to 2 milliarcseconds (mas), transforming it in a slight elliptic motion. The asymmetric contribution is relatively larger in the geodetic excitation function, for Chandler wobble excitation mixes prograde and retrograde components of comparable level (1 mas).

  6. Gravity effects on endogenous movements

    NASA Astrophysics Data System (ADS)

    Johnsson, Anders; Antonsen, Frank

    Gravity effects on endogenous movements A. Johnsson * and F. Antonsen *+ * Department of Physics, Norwegian University of Science and Technology,NO-7491, Trond-heim, Norway, E-mail: anders.johnsson@ntnu.no + Present address: Statoil Research Center Trondheim, NO-7005, Trondheim, Norway Circumnutations in stems/shoots exist in many plants and often consists of more or less regular helical movements around the plumb line under Earth conditions. Recent results on circumnu-tations of Arabidopsis in space (Johnsson et al. 2009) showed that minute amplitude oscilla-tions exist in weightlessness, but that centripetal acceleration (mimicking the gravity) amplified and/or created large amplitude oscillations. Fundamental mechanisms underlying these results will be discussed by modeling the plant tissue as a cylinder of cells coupled together. As a starting point we have modeled (Antonsen 1998) standing waves on a ring of biological cells, as first discussed in a classical paper (Turing 1952). If the coupled cells can change their water content, an `extension' wave could move around the ring. We have studied several, stacked rings of cells coupled into a cylinder that together represent a cylindrical plant tissue. Waves of extensions travelling around the cylinder could then represent the observable circumnutations. The coupling between cells can be due to cell-to-cell diffusion, or to transport via channels, and the coupling can be modeled to vary in both longitudinal and transversal direction of the cylinder. The results from ISS experiments indicate that this cylindrical model of coupled cells should be able to 1) show self-sustained oscillations without the impact of gravity (being en-dogenous) and 2) show how an environmental factor like gravity can amplify or generate the oscillatory movements. Gravity has been introduced in the model by a negative, time-delayed feed-back transport across the cylinder. This represents the physiological reactions to acceler

  7. Auxin and chloroplast movements.

    PubMed

    Eckstein, Aleksandra; Krzeszowiec, Weronika; Waligórski, Piotr; Gabryś, Halina

    2016-03-01

    Auxin is involved in a wide spectrum of physiological processes in plants, including responses controlled by the blue light photoreceptors phototropins: phototropic bending and stomatal movement. However, the role of auxin in phototropin-mediated chloroplast movements has never been studied. To address this question we searched for potential interactions between auxin and the chloroplast movement signaling pathway using different experimental approaches and two model plants, Arabidopsis thaliana and Nicotiana tabacum. We observed that the disturbance of auxin homeostasis by shoot decapitation caused a decrease in chloroplast movement parameters, which could be rescued by exogenous auxin application. In several cases, the impairment of polar auxin transport, by chemical inhibitors or in auxin carrier mutants, had a similar negative effect on chloroplast movements. This inhibition was not correlated with changes in auxin levels. Chloroplast relocations were also affected by the antiauxin p-chlorophenoxyisobutyric acid and mutations in genes encoding some of the elements of the SCF(TIR1)-Aux/IAA auxin receptor complex. The observed changes in chloroplast movement parameters are not prominent, which points to a modulatory role of auxin in this process. Taken together, the obtained results suggest that auxin acts indirectly to regulate chloroplast movements, presumably by regulating gene expression via the SCF(TIR1)-Aux/IAA-ARF pathway. Auxin does not seem to be involved in controlling the expression of phototropins.

  8. Core formation and core composition from coupled geochemical and geophysical constraints.

    PubMed

    Badro, James; Brodholt, John P; Piet, Hélène; Siebert, Julien; Ryerson, Frederick J

    2015-10-06

    The formation of Earth's core left behind geophysical and geochemical signatures in both the core and mantle that remain to this day. Seismology requires that the core be lighter than pure iron and therefore must contain light elements, and the geochemistry of mantle-derived rocks reveals extensive siderophile element depletion and fractionation. Both features are inherited from metal-silicate differentiation in primitive Earth and depend upon the nature of physiochemical conditions that prevailed during core formation. To date, core formation models have only attempted to address the evolution of core and mantle compositional signatures separately, rather than seeking a joint solution. Here we combine experimental petrology, geochemistry, mineral physics and seismology to constrain a range of core formation conditions that satisfy both constraints. We find that core formation occurred in a hot (liquidus) yet moderately deep magma ocean not exceeding 1,800 km depth, under redox conditions more oxidized than present-day Earth. This new scenario, at odds with the current belief that core formation occurred under reducing conditions, proposes that Earth's magma ocean started oxidized and has become reduced through time, by oxygen incorporation into the core. This core formation model produces a core that contains 2.7-5% oxygen along with 2-3.6% silicon, with densities and velocities in accord with radial seismic models, and leaves behind a silicate mantle that matches the observed mantle abundances of nickel, cobalt, chromium, and vanadium.

  9. Predicting chaotic climates: from Earth to super-Earths?

    NASA Astrophysics Data System (ADS)

    Read, Peter L.

    2010-10-01

    The prediction of atmospheric behaviour for the Earth has been a major arena for the application of complex mathematical ideas and techniques to geophysics and astronomy. Objective forecasting of the weather provided the first stimulus for the development of numerical methods to integrate the equations of fluid motion by L. F. Richardson in the early 20th century, leading on to their implementation in electronic computers in the 1940s and 1950s. Such an approach has now reached a highly sophisticated state with weather and climate models attempting to forecast weather and climate changes in immense detail. Such techniques have been applied to model the atmospheres of other planets in the Solar System since the 1960s, and are catching up rapidly in their sophistication with models used for the Earth. But with the expanding discoveries of planets around other stars, it is likely that alternative approaches may be needed that are more general but seek to quantify trends in the gross features of atmospheric circulation systems as a function of a small number of global parameters. By the study of simple analogues, either in the form of simplified numerical models or laboratory experiments, considerable insights may be gained as to the likely roles of planetary size, rotation, thermal stratification and other factors in determining the principal length scales, styles of global circulation and dominant waves and instability processes active in all planetary atmospheres. In this review, we explore aspects of these analogues and demonstrate the importance of a number of key dimensionless parameters, most notably thermal Rossby and Burger numbers and a measure of the dominant frictional or radiative timescale, in defining the type of circulation regime to be expected in a prototype planetary atmosphere subject to axisymmetric driving. These considerations help to place Mars, Venus, Titan and Earth into an appropriate context, and may also lay the foundations for predicting

  10. Ames Research Center SR&T program and earth observations

    NASA Technical Reports Server (NTRS)

    Poppoff, I. G.

    1972-01-01

    An overview is presented of the research activities in earth observations at Ames Research Center. Most of the tasks involve the use of research aircraft platforms. The program is also directed toward the use of the Illiac 4 computer for statistical analysis. Most tasks are weighted toward Pacific coast and Pacific basin problems with emphasis on water applications, air applications, animal migration studies, and geophysics.

  11. Geophysical parameters from the analysis of laser ranging to Starlette

    NASA Technical Reports Server (NTRS)

    Schutz, B. E.; Shum, C. K.; Tapley, B. D.

    1992-01-01

    The results of geodynamic research from the analysis of satellite laser ranging data to Starlette are summarized. The time period of the investigation was from 15 Mar. 1986 to 31 Dec. 1991. As a result of the Starlette research, a comprehensive 16-year Starlette data set spanning the time period from 17 Mar. 1975 through 31 Dec. 1990, was produced. This data set represents the longest geophysical time series from any geodetic satellite and is invaluable for research in long-term geodynamics. A low degree and order ocean tide solution determined from Starlette has good overall agreement with other satellite and oceanographic tide solutions. The observed lunar deceleration is -24.7 +/- 0.6 arcsecond/century(exp 2), which agrees well with other studies. The estimated value of J2 is (-2.5 +/- 0.3) x 10(exp -11) yr(exp -1), assuming there are no variations in higher degree zonals and that the 18.6-year tide is fixed at an equilibrium value. The yearly fluctuations in the values for S(sub a) and S(sub sa) tides determined by the 16-year Starlette data are found to be associated with changes in the Earth's second degree zonal harmonic caused primarily by meteorological excitation. The mean values for the amplitude of S(sub a) and S(sub sa) variations in J2 are 32.3 x 10(exp -11) and 19.5 x 10(exp -11), respectively; while the rms about the mean values are 4.1 x 10(exp -11) and 6.3(10)(exp -11), respectively. The annual delta(J2) is in good agreement with the value obtained from the combined effects of air mass redistribution without the oceanic inverted-barometer effects and hydrological change. The annual delta(J3) values have much larger disagreements. Approximately 90 percent of the observed annual variation from Starlette is attributed to the meteorological mass redistribution occurring near the Earth's surface.

  12. The Earth's variable Chandler wobble

    NASA Astrophysics Data System (ADS)

    Bizouard, C.; Remus, F.; Lambert, S. B.; Seoane, L.; Gambis, D.

    2011-02-01

    Aims: We investigated the causes of the Earth's Chandler wobble variability over the past 60 years. Our approach is based on integrating of the atmospheric and oceanic angular momentum computed by global circulation models. We directly compared the result of the integration with the Earth's pole coordinate observed by precise astrometric, space, and geodetic techniques. This approach differs from the traditional approach in which the observed polar motion is transformed into a so-called geodetic excitation function, and compared afterwards with the angular momentum of the external geophysical fluid layers. Methods: In the time domain, we integrated the atmospheric angular momentum time series from the National Center for Environmental Prediction/National Center for Atmospheric Research Reanalysis project and the oceanic angular momentum data from the ECCO consortium. We extracted the Chandler wobble from this modeled polar motion by singular spectrum analysis, and compared it with the Chandler wobble extracted from the observed polar motion given by the International Earth Rotation and Reference Systems Service data. Results: We showed that the combination of the atmosphere and the oceans explains most of the observed Chandler wobble variations, and is consistent with results reported in the literature and obtained with the traditional approach. Our approach allows one to appreciate the separate contributions of the atmosphere and the oceans to the various bumps and valleys observed in the Chandler wobble. Though the atmosphere explains the Chandler wobble amplitude variations between 1949 and 1970, the reexcitation of the Chandler wobble that begins in the 1980s, after a minimum around 1970, and that reaches its maximum in the late 1990s is due to the oceans, while the atmospheric contribution remains stable within the same period.

  13. New Geophysical Techniques for Offshore Exploration.

    ERIC Educational Resources Information Center

    Talwani, Manik

    1983-01-01

    New seismic techniques have been developed recently that borrow theory from academic institutions and technology from industry, allowing scientists to explore deeper into the earth with much greater precision than possible with older seismic methods. Several of these methods are discussed, including the seismic reflection common-depth-point…

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

    NASA Astrophysics Data System (ADS)

    Bernatek-Jakiel, Anita; Kondracka, Marta

    2016-12-01

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

  15. Eye movement tics.

    PubMed Central

    Shawkat, F; Harris, C M; Jacobs, M; Taylor, D; Brett, E M

    1992-01-01

    An 8-year-old girl presented with opsoclonus-like eye movement and an 18 month history of intermittent facial tics. Investigations were all normal. Electro-oculography showed the eye movements to be of variable amplitude (10-40 degrees), with no intersaccadic interval, and with a frequency of 3-4 Hz. Saccades, smooth pursuit, optokinetic, and vestibular reflexes were all normal. These abnormal eye movements eventually disappeared. It is thought that they were a form of ocular tics. PMID:1477052

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  17. Basic research and data analysis for the National Geodetic Satellite Program and for the Earth and Ocean Physics Application Program

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Accomplishments in the continuing programs are reported. The data were obtained in support of the following broad objectives: (1) to provide a precise and accurate geometric description of the earth's surface; (2) to provide a precise and accurate mathematical description of the earth's gravitational field; and (3) to determine time variations of the geometry of the ocean surface, the solid earth, the gravity field, and other geophysical parameters.

  18. The Forced Annual Wobble in Earth's Polar Motion

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

    The annual wobble in Earth's polar motion is a forced motion, as opposed to an excited natural oscillation which is the Chandler wobble in the case of polar motion. It is forced by the combination of many angular momentum variations in the geophysical fluids that exchange these variations with the solid Earth, hence changing its rotation. Among all forcing sources of the annual wobble the geophysical fluid that has the dominant contribution is the atmosphere, while the oceans and the land hydrology make up the remaining budget together with tidal influences. The latter include that from the solid Earth deformation and that from the ocean tides at the annual period. The combined forcing produces both prograde and retrograde wobbles; the prograde wobble gets magnified substantially by the near-by presence of the natural Chandler wobble resonance. On the other hand, the closeness of the prograde annual forcing power to the Chandler period is an indication that some of the power leakage into the Chandler period band becomes the main excitation source for the Chandler wobble. In this paper we will review our knowledge about annual wobble and show the status in the effort of closing the budget with the annual angular momentum variations from the various geophysical fluids.

  19. Geophysical survey at Tell Barri (Syria)

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  20. Movement and Coordination

    MedlinePlus

    ... the Word Shop AAP Find a Pediatrician Ages & Stages Prenatal Baby Toddler Fitness Nutrition Toilet Training Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Toddler > Movement and Coordination Ages & Stages Listen Español ...