Computational geomechanics and applications at Sandia National Laboratories

International Nuclear Information System (INIS)

Arguello, Jose Guadalupe Jr.

2010-01-01

Sandia National Laboratories (SNL) is a multi-program national laboratory in the business of national security, whose primary mission is nuclear weapons (NW). It is a prime contractor to the USDOE, operating under the NNSA and is one of the three NW national laboratories. It has a long history of involvement in the area of geomechanics, starting with the some of the earliest weapons tests at Nevada. Projects in which geomechanics support (in general) and computational geomechanics support (in particular) are at the forefront at Sandia, range from those associated with civilian programs to those in the defense programs. SNL has had significant involvement and participation in the Waste Isolation Pilot Plant (low-level defense nuclear waste), the Yucca Mountain Project (formerly proposed for commercial spent fuel and high-level nuclear waste), and the Strategic Petroleum Reserve (the nation's emergency petroleum store). In addition, numerous industrial partners seek-out our computational/geomechanics expertise, and there are efforts in compressed air and natural gas storage, as well as in CO 2 Sequestration. Likewise, there have also been collaborative past efforts in the areas of compactable reservoir response, the response of salt structures associated with reservoirs, and basin modeling for the Oil and Gas industry. There are also efforts on the defense front, ranging from assessment of vulnerability of infrastructure to defeat of hardened targets, which require an understanding and application of computational geomechanics. Several examples from some of these areas will be described and discussed to give the audience a flavor of the type of work currently being performed at Sandia in the general area of geomechanics.

Geomechanical Study of Bakken Formation for Improved Oil Recovery

Energy Technology Data Exchange (ETDEWEB)

Ling, Kegang; Zeng, Zhengwen; He, Jun; Pei, Peng; Zhou, Xuejun; Liu, Hong; Huang, Luke; Ostadhassan, Mehdi; Jabbari, Hadi; Blanksma, Derrick; Feilen, Harry; Ahmed, Salowah; Benson, Steve; Mann, Michael; LeFever, Richard; Gosnold, Will

2013-12-31

On October 1, 2008 US DOE-sponsored research project entitled “Geomechanical Study of Bakken Formation for Improved Oil Recovery” under agreement DE-FC26-08NT0005643 officially started at The University of North Dakota (UND). This is the final report of the project; it covers the work performed during the project period of October 1, 2008 to December 31, 2013. The objectives of this project are to outline the methodology proposed to determine the in-situ stress field and geomechanical properties of the Bakken Formation in Williston Basin, North Dakota, USA to increase the success rate of horizontal drilling and hydraulic fracturing so as to improve the recovery factor of this unconventional crude oil resource from the current 3% to a higher level. The success of horizontal drilling and hydraulic fracturing depends on knowing local in-situ stress and geomechanical properties of the rocks. We propose a proactive approach to determine the in-situ stress and related geomechanical properties of the Bakken Formation in representative areas through integrated analysis of field and well data, core sample and lab experiments. Geomechanical properties are measured by AutoLab 1500 geomechanics testing system. By integrating lab testing, core observation, numerical simulation, well log and seismic image, drilling, completion, stimulation, and production data, in-situ stresses of Bakken formation are generated. These in-situ stress maps can be used as a guideline for future horizontal drilling and multi-stage fracturing design to improve the recovery of Bakken unconventional oil.

The Geomechanics of CO₂ Storage in Deep Sedimentary Formations

Energy Technology Data Exchange (ETDEWEB)

Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-01-12

This study provides a review of the geomechanics and modeling of geomechanics associated with geologic carbon storage (GCS), focusing on storage in deep sedimentary formations, in particular saline aquifers. The paper first introduces the concept of storage in deep sedimentary formations, the geomechanical processes and issues related with such an operation, and the relevant geomechanical modeling tools. This is followed by a more detailed review of geomechanical aspects, including reservoir stress-strain and microseismicity, well integrity, caprock sealing performance, and the potential for fault reactivation and notable (felt) seismic events. Geomechanical observations at current GCS field deployments, mainly at the In Salah CO₂ storage project in Algeria, are also integrated into the review. The In Salah project, with its injection into a relatively thin, low-permeability sandstone is an excellent analogue to the saline aquifers that might be used for large scale GCS in parts of Northwest Europe, the U.S. Midwest, and China. Some of the lessons learned at In Salah related to geomechanics are discussed, including how monitoring of geomechanical responses is used for detecting subsurface geomechanical changes and tracking fluid movements, and how such monitoring and geomechanical analyses have led to preventative changes in the injection parameters. Recently, the importance of geomechanics has become more widely recognized among GCS stakeholders, especially with respect to the potential for triggering notable (felt) seismic events and how such events could impact the long-term integrity of a CO₂ repository (as well as how it could impact the public perception of GCS). As described in the paper, to date, no notable seismic event has been reported from any of the current CO₂ storage projects, although some unfelt microseismic activities have been detected by geophones. However, potential future commercial GCS operations from large

Geochemistry of subduction zone serpentinites: A review

OpenAIRE

DESCHAMPS, Fabien; GODARD, Marguerite; GUILLOT, Stéphane; HATTORI, Kéiko

2013-01-01

Over the last decades, numerous studies have emphasized the role of serpentinites in the subduction zone geodynamics. Their presence and role in subduction environments are recognized through geophysical, geochemical and field observations of modern and ancient subduction zones and large amounts of geochemical database of serpentinites have been created. Here, we present a review of the geochemistry of serpentinites, based on the compilation of ~ 900 geochemical data of abyssal, mantle wedge ...

Development of the T+M coupled flow–geomechanical simulator to describe fracture propagation and coupled flow–thermal–geomechanical processes in tight/shale gas systems

Energy Technology Data Exchange (ETDEWEB)

Kim, Jihoon; Moridis, George J.

2013-10-01

We developed a hydraulic fracturing simulator by coupling a flow simulator to a geomechanics code, namely T+M simulator. Modeling of the vertical fracture development involves continuous updating of the boundary conditions and of the data connectivity, based on the finite element method for geomechanics. The T+M simulator can model the initial fracture development during the hydraulic fracturing operations, after which the domain description changes from single continuum to double or multiple continua in order to rigorously model both flow and geomechanics for fracture-rock matrix systems. The T+H simulator provides two-way coupling between fluid-heat flow and geomechanics, accounting for thermoporomechanics, treats nonlinear permeability and geomechanical moduli explicitly, and dynamically tracks changes in the fracture(s) and in the pore volume. We also fully accounts for leak-off in all directions during hydraulic fracturing. We first validate the T+M simulator, matching numerical solutions with the analytical solutions for poromechanical effects, static fractures, and fracture propagations. Then, from numerical simulation of various cases of the planar fracture propagation, shear failure can limit the vertical fracture propagation of tensile failure, because of leak-off into the reservoirs. Slow injection causes more leak-off, compared with fast injection, when the same amount of fluid is injected. Changes in initial total stress and contributions of shear effective stress to tensile failure can also affect formation of the fractured areas, and the geomechanical responses are still well-posed.

Geomechanical Modeling for Improved CO2 Storage Security

Science.gov (United States)

Rutqvist, J.; Rinaldi, A. P.; Cappa, F.; Jeanne, P.; Mazzoldi, A.; Urpi, L.; Vilarrasa, V.; Guglielmi, Y.

2017-12-01

This presentation summarizes recent modeling studies on geomechanical aspects related to Geologic Carbon Sequestration (GCS,) including modeling potential fault reactivation, seismicity and CO2 leakage. The model simulations demonstrates that the potential for fault reactivation and the resulting seismic magnitude as well as the potential for creating a leakage path through overburden sealing layers (caprock) depends on a number of parameters such as fault orientation, stress field, and rock properties. The model simulations further demonstrate that seismic events large enough to be felt by humans requires brittle fault properties as well as continuous fault permeability allowing for the pressure to be distributed over a large fault patch to be ruptured at once. Heterogeneous fault properties, which are commonly encountered in faults intersecting multilayered shale/sandstone sequences, effectively reduce the likelihood of inducing felt seismicity and also effectively impede upward CO2 leakage. Site specific model simulations of the In Salah CO2 storage site showed that deep fractured zone responses and associated seismicity occurred in the brittle fractured sandstone reservoir, but at a very substantial reservoir overpressure close to the magnitude of the least principal stress. It is suggested that coupled geomechanical modeling be used to guide the site selection and assisting in identification of locations most prone to unwanted and damaging geomechanical changes, and to evaluate potential consequence of such unwanted geomechanical changes. The geomechanical modeling can be used to better estimate the maximum sustainable injection rate or reservoir pressure and thereby provide for improved CO2 storage security. Whether damaging geomechanical changes could actually occur very much depends on the local stress field and local reservoir properties such the presence of ductile rock and faults (which can aseismically accommodate for the stress and strain induced by

Bayou Choctaw Well Integrity Grading Component Based on Geomechanical Simulation

Energy Technology Data Exchange (ETDEWEB)

Park, Byoung [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Geotechnology & Engineering Dept.

2016-09-08

This letter report provides a Bayou Choctaw (BC) Strategic Petroleum Reserve (SPR) well grading system based on the geomechanical simulation. The analyses described in this letter were used to evaluate the caverns’ geomechanical effect on wellbore integrity, which is an important component in the well integrity grading system recently developed by Roberts et al. [2015]. Using these analyses, the wellbores for caverns BC-17 and 20 are expected to be significantly impacted by cavern geomechanics, BC-18 and 19 are expected to be medium impacted; and the other caverns are expected to be less impacted.

Sedimentary basin geochemistry and fluid/rock interactions workshop

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-12-31

Fundamental research related to organic geochemistry, fluid-rock interactions, and the processes by which fluids migrate through basins has long been a part of the U.S. Department of Energy Geosciences program. Objectives of this program were to emphasize those principles and processes which would be applicable to a wide range of problems associated with petroleum discovery, occurrence and extraction, waste disposal of all kinds, and environmental management. To gain a better understanding of the progress being made in understanding basinal fluids, their geochemistry and movement, and related research, and to enhance communication and interaction between principal investigators and DOE and other Federal program managers interested in this topic, this workshop was organized by the School of Geology and Geophysics and held in Norman, Oklahoma in November, 1991.

Back Analysis of Geomechanical Parameters in Underground Engineering Using Artificial Bee Colony

Directory of Open Access Journals (Sweden)

Changxing Zhu

2014-01-01

Full Text Available Accurate geomechanical parameters are critical in tunneling excavation, design, and supporting. In this paper, a displacements back analysis based on artificial bee colony (ABC algorithm is proposed to identify geomechanical parameters from monitored displacements. ABC was used as global optimal algorithm to search the unknown geomechanical parameters for the problem with analytical solution. To the problem without analytical solution, optimal back analysis is time-consuming, and least square support vector machine (LSSVM was used to build the relationship between unknown geomechanical parameters and displacement and improve the efficiency of back analysis. The proposed method was applied to a tunnel with analytical solution and a tunnel without analytical solution. The results show the proposed method is feasible.

Constitutive Modelling in Geomechanics Introduction

CERN Document Server

Puzrin, Alexander M

2012-01-01

The purpose of this book is to bridge the gap between the traditional Geomechanics and Numerical Geotechnical Modelling with applications in science and practice. Geomechanics is rarely taught within the rigorous context of Continuum Mechanics and Thermodynamics, while when it comes to Numerical Modelling, commercially available finite elements or finite differences software utilize constitutive relationships within the rigorous framework. As a result, young scientists and engineers have to learn the challenging subject of constitutive modelling from a program manual and often end up with using unrealistic models which violate the Laws of Thermodynamics.  The book is introductory, by no means does it claim any completeness and state of the art in such a dynamically developing field as numerical and constitutive modelling of soils. The author gives basic understanding of conventional continuum mechanics approaches to constitutive modelling, which can serve as a foundation for exploring more advanced theories....

Coupled Geomechanical-Flow Assessment of CO2 Leakage through Heterogeneous Caprock during CCS

Directory of Open Access Journals (Sweden)

Guan Woo Kim

2018-01-01

Full Text Available The viability of carbon capture sequestration (CCS is dependent on the secure storage of CO2 in subsurface geologic formations. Geomechanical failure of caprock is one of the main reasons of CO2 leakage from the storage formations. Through comprehensive assessment on the petrophysical and geomechanical heterogeneities of caprock, it is possible to predict the risk of unexpected caprock failure. To describe the fracture reactivation, the modified Barton–Bandis model is applied. In order to generate hydro-geomechanically heterogeneous fields, the negative correlation between porosity and Young’s modulus/Poisson’s ratio is applied. In comparison with the homogeneous model, effects of heterogeneity are examined in terms of vertical deformation and the amount of leaked CO2. To compare the effects of heterogeneity, heterogeneous models for both geomechanical and petrophysical properties in coupled simulation are designed. After 10-year injection with petrophysically heterogeneous and geomechanically homogeneous caprock, CO2 leakage is larger than that of the homogeneous model. In contrast, heterogeneity of geomechanical properties is shown to mitigate additional escape of CO2. Vertical displacement of every heterogeneous model is larger than homogeneous model. The model with compressive tectonic stress shows much more stable trapping with heterogeneous caprock, but there is possibility of rapid leakage after homogeneous caprock failure.

Prediction of Geomechanical Properties from Thermal Conductivity of Low-Permeable Reservoirs

Science.gov (United States)

Chekhonin, Evgeny; Popov, Evgeny; Popov, Yury; Spasennykh, Mikhail; Ovcharenko, Yury; Zhukov, Vladislav; Martemyanov, Andrey

2016-04-01

A key to assessing a sedimentary basin's hydrocarbon prospect is correct reconstruction of thermal and structural evolution. It is impossible without adequate theory and reliable input data including among other factors thermal and geomechanical rock properties. Both these factors are also important in geothermal reservoirs evaluation and carbon sequestration problem. Geomechanical parameters are usually estimated from sonic logging and rare laboratory measurements, but sometimes it is not possible technically (low quality of the acoustic signal, inappropriate borehole and mud conditions, low core quality). No wonder that there are attempts to correlate the thermal and geomechanical properties of rock, but no one before did it with large amount of high quality thermal conductivity data. Coupling results of sonic logging and non-destructive non-contact thermal core logging opens wide perspectives for studying a relationship between the thermal and geomechanical properties. More than 150 m of full size cores have been measured at core storage with optical scanning technique. Along with results of sonic logging performed with Sonic Scanner in different wells drilled in low permeable formations in West Siberia (Russia) it provided us with unique data set. It was established a strong correlation between components of thermal conductivity (measured perpendicular and parallel to bedding) and compressional and shear acoustic velocities in Bazhen formation. As a result, prediction of geomechanical properties via thermal conductivity data becomes possible, corresponding results was demonstrated. The work was supported by the Russian Ministry of Education and Science, project No. RFMEFI58114X0008.

Geomechanical monitoring system at the Waste Isolation Pilot Plant, Carlsbad, New Mexico

International Nuclear Information System (INIS)

Francke, J.L.; Carrasco, R.C.

1992-01-01

This paper describes in detail the geomechanical instrumentation system and the database that has been established from the geomechanical monitoring program. In addition, it describes the quality assurance and control measures that are in place to ensure that the data from the underground is accurate, traceable, and defensible. The system is installed at the Waste Isolation Pilot Plant in Carlsbad, New Mexico. This facility is being developed for the disposal of transuranic nuclear wastes in underground excavations in salt 655 meters below the surface. The purpose of the instrumentation system, is to monitor the deformations and stress changes that are occurring in the rock with time. This information is needed to routinely assess conditions in the facility and to ensure that safe operating conditions are maintained. The geomechanical monitoring system has provided data collection, quality control, and database maintenance, all of which are of vital importance to monitoring the geomechanical performance of underground excavations

Modelling Geomechanical Heterogeneity of Rock Masses Using Direct and Indirect Geostatistical Conditional Simulation Methods

Science.gov (United States)

Eivazy, Hesameddin; Esmaieli, Kamran; Jean, Raynald

2017-12-01

An accurate characterization and modelling of rock mass geomechanical heterogeneity can lead to more efficient mine planning and design. Using deterministic approaches and random field methods for modelling rock mass heterogeneity is known to be limited in simulating the spatial variation and spatial pattern of the geomechanical properties. Although the applications of geostatistical techniques have demonstrated improvements in modelling the heterogeneity of geomechanical properties, geostatistical estimation methods such as Kriging result in estimates of geomechanical variables that are not fully representative of field observations. This paper reports on the development of 3D models for spatial variability of rock mass geomechanical properties using geostatistical conditional simulation method based on sequential Gaussian simulation. A methodology to simulate the heterogeneity of rock mass quality based on the rock mass rating is proposed and applied to a large open-pit mine in Canada. Using geomechanical core logging data collected from the mine site, a direct and an indirect approach were used to model the spatial variability of rock mass quality. The results of the two modelling approaches were validated against collected field data. The study aims to quantify the risks of pit slope failure and provides a measure of uncertainties in spatial variability of rock mass properties in different areas of the pit.

GEOMECHANICAL OBSERVATIONS DURING THE LARGE BLOCK TEST

International Nuclear Information System (INIS)

STEPHEN C. BLAIR AND STEPHANIE A. WOOD

1998-01-01

This paper presents an overview of the geomechanical studies conducted at the Large Block Test at Fran Ridge, near Yucca Mountain, Nevada. The 3-dimensional geomechanical response of the rock to heating is being monitored using instrumentation mounted in boreholes and on the surface of the block. Results show that thermal expansion of the block began a few hours after the start of heating, and is closely correlated with the thermal history. Horizontal expansion increases as a linear function of height. Comparison of observed deformations with continuum simulations shows that below the heater plane deformation is smaller than predicted, while above the heater plane, observed deformation is larger than predicted, and is consistent with opening of vertical fractures. Fracture monitors indicate that movement on a large horizontal fracture is associated with hydrothermal behavior

Contribution of the geology and geochemistry modelling to the petroleum industry

International Nuclear Information System (INIS)

Tissot, B.

1993-01-01

Evolution of modelling and model interpretation in the domain of geology, geophysics and geochemistry applied to petroleum industry, is first summarized. Hydrocarbon geological formation modelling is then presented in details with examples of kinetic models such as the discrete distribution and the Gaussian distribution based models, and the kerogene to petroleum process modelling. Petroleum basin modelling is also discussed with methods such as back-stripping, conductive thermal transfers, etc. 14 figs., 26 refs

Geotechnical applications of LiDAR pertaining to geomechanical evaluation and hazard identification

Science.gov (United States)

Lato, Matthew J.

Natural hazards related to ground movement that directly affect the safety of motorists and highway infrastructure include, but are not limited to, rockfalls, rockslides, debris flows, and landslides. This thesis specifically deals with the evaluation of rockfall hazards through the evaluation of LiDAR data. Light Detection And Ranging (LiDAR) is an imaging technology that can be used to delineate and evaluate geomechanically-controlled hazards. LiDAR has been adopted to conduct hazard evaluations pertaining to rockfall, rock-avalanches, debris flows, and landslides. Characteristics of LiDAR surveying, such as rapid data acquisition rates, mobile data collection, and high data densities, pose problems to traditional CAD or GIS-based mapping methods. New analyses methods, including tools specifically oriented to geomechanical analyses, are needed. The research completed in this thesis supports development of new methods, including improved survey techniques, innovative software workflows, and processing algorithms to aid in the detection and evaluation of geomechanically controlled rockfall hazards. The scientific research conducted between the years of 2006-2010, as presented in this thesis, are divided into five chapters, each of which has been published by or is under review by an international journal. The five research foci are: (i) geomechanical feature extraction and analysis using LiDAR data in active mining environments; (ii) engineered monitoring of rockfall hazards along transportation corridors: using mobile terrestrial LiDAR; (iii) optimization of LiDAR scanning and processing for automated structural evaluation of discontinuities in rockmasses; (iv) location orientation bias when using static LiDAR data for geomechanical analysis; and (v) evaluating roadside rockmasses for rockfall hazards from LiDAR data: optimizing data collection and processing protocols. The research conducted pertaining to this thesis has direct and significant implications with

Integrated geomechanical, petrographical and petrophysical study of the sandstones of the Wajid Group, SW Saudi Arabia

Science.gov (United States)

Benaafi, Mohammed; Hariri, Mustafa; Al-Shaibani, Abdulaziz; Abdullatif, Osman; Makkawi, Mohammed

2018-07-01

The Cambro-Permian siliciclastic succession in southwestern Saudi Arabia is represented by the Wajid Group, which consists mainly of fluvial, shallow marine, aeolian, and glacial sandstones. The Wajid Group comprises the Dibsiyah, Sanamah, Qalibah, Khusayyayn, and Juwayl Formations. It is exposed in the Wadi Al-Dawasir area and extends to Najran City. The sandstones of the Wajid Group serve as groundwater aquifers in the Wadi Al-Dawasir and Najran areas and host hydrocarbon (mainly gas) reservoirs in the Rub' Al-Khali Basin. This study aims to characterize the geomechanical properties (rock strength and Young's modulus) of the sandstones of the Wajid Group using field and experimental techniques. A further objective is to investigate the relationships between the geomechanical properties and the petrographical and petrophysical properties of the studied sandstones. The geomechanical properties of the studied sandstones vary from glacial to non-glacial sandstones, as the glacial sandstones display high values of the geomechanical properties with high variability indices. Four geological factors including grain size, cement content, porosity and permeability were observed as the main controls on the geomechanical behaviour of the studied sandstones except for the Khusayyayn sandstone, where the mineral composition was also important. Significant correlations were observed between the petrographical and petrophysical properties and the geomechanical properties of the glacial sandstones. Predictive models of the geomechanical properties (RN, UCS, and E) were generated using regression analysis to account for the glacial sandstones.

Origin of the Moon new concept geochemistry and dynamics

CERN Document Server

Galimov, Erik M

2012-01-01

The origin of the Moon remains an unsolved problem of the planetary science. Researchers engaged in celestial dynamics, geophysics, and geochemistry are still discussing various models of creation of our closest cosmic neighbour. The most popular scenario, the impact hypothesis involving a collision early in the Earth's history, has been substantially challenged by the new data. The birth and development of a planet-moon system always play a role in the formation of an entire planetary system around our Sun or around another star. This way, the story of our Moon acquires broader ramifications

Dynamic use of geoscience information to develop scientific understanding for a nuclear waste repository

International Nuclear Information System (INIS)

Cook, N.G.W.; Tsang, C.F.

1990-01-01

The development and safety evaluation of a nuclear waste geologic repository require a proper scientific understanding of the site response. Such scientific understanding depends on information from a number of geoscience disciplines, including geology, geophysics, geochemistry, geomechanics and hydrogeology. The information comes in four stages: (1) general regional survey data base, (2) surface-based testing, (3) exploratory shaft testing, and (4) repository construction and evaluation. A discussion is given on the dynamic use of the information through the different stages. We point out the need for abstracting, deriving and updating a quantitative spatial and process model (QSPM) to develop a scientific understanding of site responses as a crucial element in the dynamic procedure. 2 figs

Geomechanical investigations for the designing of cemented filling

Energy Technology Data Exchange (ETDEWEB)

Berry, P.

1980-05-15

Laboratory and in situ investigations have led to the identification of the main geomechanical parameters that condition the stability of the cemented fill in the Gavorrano pyrite mine (Tuscany, Italy); such parameters were used for working out a satisfactory mining method. The pyrite is mined with the descending horizontal slice method with integral cemented filling which is obtained by throwing a mixture of limestone aggregates and cement into the mined voids. The laboratory geomechanical investigations carried out on fill samples have pointed out that the physical and mechanical characteristics are highly variable and this is essentially due to the fact that the fill is cast into place by compressed air. In particular, it was pointed out that the strength depends upon the cement content and upon the porosity according to a power law. The in situ measurements of the convergence between the roof and the floor, and the load measurements pointed out the considerable importance of the horizontal and vertical joints that cross the fill mass and that are inevitably brought about by a discontinuity of the fill. The results of the study made it possible to adopt an acceptable geomechanical behaviour model of the fill. On the basis of this model the mining pattern was deeply modified, the width and the height of the slices were considerably enlarged and thus the output was improved.

Prediction of tectonic stresses and fracture networks with geomechanical reservoir models

International Nuclear Information System (INIS)

Henk, A.; Fischer, K.

2014-09-01

This project evaluates the potential of geomechanical Finite Element (FE) models for the prediction of in situ stresses and fracture networks in faulted reservoirs. Modeling focuses on spatial variations of the in situ stress distribution resulting from faults and contrasts in mechanical rock properties. In a first methodological part, a workflow is developed for building such geomechanical reservoir models and calibrating them to field data. In the second part, this workflow was applied successfully to an intensively faulted gas reservoir in the North German Basin. A truly field-scale geomechanical model covering more than 400km 2 was built and calibrated. It includes a mechanical stratigraphy as well as a network of 86 faults. The latter are implemented as distinct planes of weakness and allow the fault-specific evaluation of shear and normal stresses. A so-called static model describes the recent state of the reservoir and, thus, after calibration its results reveal the present-day in situ stress distribution. Further geodynamic modeling work considers the major stages in the tectonic history of the reservoir and provides insights in the paleo stress distribution. These results are compared to fracture data and hydraulic fault behavior observed today. The outcome of this project confirms the potential of geomechanical FE models for robust stress and fracture predictions. The workflow is generally applicable and can be used for modeling of any stress-sensitive reservoir.

Prediction of tectonic stresses and fracture networks with geomechanical reservoir models

Energy Technology Data Exchange (ETDEWEB)

Henk, A.; Fischer, K. [TU Darmstadt (Germany). Inst. fuer Angewandte Geowissenschaften

2014-09-15

This project evaluates the potential of geomechanical Finite Element (FE) models for the prediction of in situ stresses and fracture networks in faulted reservoirs. Modeling focuses on spatial variations of the in situ stress distribution resulting from faults and contrasts in mechanical rock properties. In a first methodological part, a workflow is developed for building such geomechanical reservoir models and calibrating them to field data. In the second part, this workflow was applied successfully to an intensively faulted gas reservoir in the North German Basin. A truly field-scale geomechanical model covering more than 400km{sup 2} was built and calibrated. It includes a mechanical stratigraphy as well as a network of 86 faults. The latter are implemented as distinct planes of weakness and allow the fault-specific evaluation of shear and normal stresses. A so-called static model describes the recent state of the reservoir and, thus, after calibration its results reveal the present-day in situ stress distribution. Further geodynamic modeling work considers the major stages in the tectonic history of the reservoir and provides insights in the paleo stress distribution. These results are compared to fracture data and hydraulic fault behavior observed today. The outcome of this project confirms the potential of geomechanical FE models for robust stress and fracture predictions. The workflow is generally applicable and can be used for modeling of any stress-sensitive reservoir.

Scientific days, ANDRA 1999. Summary of conferences and poster communications; Journees scientifiques, ANDRA 1999. Resume des conferences et des communications par affiches

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-01

This document summarizes the content of the 1999 scientific conference days organized by the French national agency of radioactive wastes (ANDRA). The content comprises: the opening session (2 talks), 4 general conferences dealing with important questions relative to feasibility studies of waste disposal. These conferencesare complementary to the four technical sessions developed thereafter (hydro-geochemistry and solutes transport in the geosphere; storage materials; geomechanics; research programs in underground laboratories). A large part of the conference was devoted to poster sessions on the following topics: geology, hydro-geochemistry and hydrogeology, geomechanics, storage materials (metals and clay materials), behaviour of radionuclides (geosphere, biosphere), and numerical analysis applied to hydro-geochemistry and transport. (J.S.)

Scientific days, ANDRA 1999. Summary of conferences and poster communications

International Nuclear Information System (INIS)

1999-12-01

This document summarizes the content of the 1999 scientific conference days organized by the French national agency of radioactive wastes (ANDRA). The content comprises: the opening session (2 talks), 4 general conferences dealing with important questions relative to feasibility studies of waste disposal. These conferences are complementary to the four technical sessions developed thereafter (hydro-geochemistry and solutes transport in the geosphere; storage materials; geomechanics; research programs in underground laboratories). A large part of the conference was devoted to poster sessions on the following topics: geology, hydro-geochemistry and hydrogeology, geomechanics, storage materials (metals and clay materials), behaviour of radionuclides (geosphere, biosphere), and numerical analysis applied to hydro-geochemistry and transport. (J.S.)

V Congress of Spanish Geochemistry

International Nuclear Information System (INIS)

1993-01-01

This proceedings book present the lectures of V Spanish geochemistry Congress. The sessions were: 1.- Materials geochemistry and geologic process. 2.- Geochemistry prospection 3.- Environmental geochemistry 4.- Isotopic geochemistry 5.- Organic geochemistry 6.- Natural materials geochemistry for industry 7.- Hydrogeochemistry 8.- Mathematical models in geochemistry 9.- Analysis methods in geochemistry 10.-Training of geochemistry 11.-Cosmochemistry

Coupling a fluid flow simulation with a geomechanical model of a fractured reservoir

OpenAIRE

Segura Segarra, José María; Paz, C.M.; de Bayser, M.; Zhang, J.; Bryant, P.W.; Gonzalez, Nubia Aurora; Rodrigues, E.; Vargas, P.E.; Carol, Ignacio; Lakshmikantha, Ramasesha Mookanahallipatna; Das, K. C.; Sandha, S.S.; Cerqueira, R.; Mello,, U.

2013-01-01

Improving the reliability of integrated reservoir development planning and addressing subsidence, fault reactivation and other environmental impacts, requires increasingly sophisticated geomechanical models, especially in the case of fractured reservoirs where fracture deformation is strongly coupled with its permeability change. Reservoir simulation has historically treated any geomechanical effects by means of a rock compressibility term/table, which can be improved by simulating the actual...

Efem vs. XFEM: a comparative study for modeling strong discontinuity in geomechanics

OpenAIRE

Das, Kamal C.; Ausas, Roberto Federico; Segura Segarra, José María; Narang, Ankur; Rodrigues, Eduardo; Carol, Ignacio; Lakshmikantha, Ramasesha Mookanahallipatna; Mello,, U.

2015-01-01

Modeling of big faults or weak planes of strong and weak discontinuities is of major importance to assess the Geomechanical behaviour of mining/civil tunnel, reservoirs etc. For modelling fractures in Geomechanics, prior art has been limited to Interface Elements which suffer from numerical instability and where faults are required to be aligned with element edges. In this paper, we consider comparative study on finite elements for capturing strong discontinuities by means of elemental (EFEM)...

The application of nuclear geophysics method to evaluate the geological environment of nuclear waste repository

International Nuclear Information System (INIS)

Fang, Fang; Xiaoqin, Wang; Kuanliang, Li; Xinsheng, Hou; Jingliang, Zhu; Binxin, Hu

2002-01-01

'Cleanly land should be given back ground.' This is a task while nuclear engineering have to be retired. We applied the nuclear geophysics methods and combined with geology, hydrology, geochemistry, and other methods, to evaluate the environment of nuclear waste repository. It is the important work to renovate environment and prepare technology before ex-service of the nuclear engineering

CO2 geosequestration at the laboratory scale: Combined geophysical and hydromechanical assessment of weakly-cemented shallow Sleipner-like reservoirs

Science.gov (United States)

Falcon-Suarez, I.; North, L. J.; Best, A. I.

2017-12-01

To date, the most promising mitigation strategy for reducing global carbon emissions is Carbon Capture and Storage (CCS). The storage technology (i.e., CO2 geosequestration, CGS) consists of injecting CO2 into deep geological formations, specifically selected for such massive-scale storage. To guarantee the mechanical stability of the reservoir during and after injection, it is crucial to improve existing monitoring techniques for controlling CGS activities. We developed a comprehensive experimental program to investigate the integrity of the Sleipner CO2 storage site in the North Sea - the first commercial CCS project in history where 1 Mtn/y of CO2 has been injected since 1996. We assessed hydro-mechanical effects and the related geophysical signatures of three synthetic sandstones and samples from the Utsira Sand formation (main reservoir at Sleipner), at realistic pressure-temperature (PT) conditions and fluid compositions. Our experimental approach consists of brine-CO2 flow-through tests simulating variable inflation/depletion scenarios, performed in the CGS-rig (Fig. 1; Falcon-Suarez et al., 2017) at the National Oceanography Centre (NOC) in Southampton. The rig is designed for simultaneous monitoring of ultrasonic P- and S-wave velocities and attenuations, electrical resistivity, axial and radial strains, pore pressure and flow, during the co-injection of up to two fluids under controlled PT conditions. Our results show velocity-resistivity and seismic-geomechanical relations of practical importance for the distinction between pore pressure and pore fluid distribution during CGS activities. By combining geophysical and thermo-hydro-mechano-chemical coupled information, we can provide laboratory datasets that complement in situ seismic, geomechanical and electrical survey information, useful for the CO2 plume monitoring in Sleipner site and other shallow weakly-cemented sand CCS reservoirs. Falcon-Suarez, I., Marín-Moreno, H., Browning, F., Lichtschlag, A

Application of the geophysical and geochemical methods to the research for uranium; Application a la recherche de l'uranium des methodes geophysiques et geochimiques

Energy Technology Data Exchange (ETDEWEB)

Gangloff, A M; Collin, C R; Grimbert, A; Sanselme, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Since 1954, at the Commissariat a l'energie atomique, geophysics and geochemistry have been added to routine geological surveying and radiometric observations. Geophysical prospecting reveals the tectonic structures linked with French uranium deposits and gives an idea of favorable zones. Geochemistry adds to the geophysical indirect methods further details on the distribution of uranium traces in the soils. This method is direct and specific. Uranium assay in waters and alluvial deposits find its use in preliminary exploration. (author) [French] Depuis 1954, au CEA, a l'observation geologique directe et aux mesures radiometriques, sont venues s'ajouter des methodes relevant de la geophysique et de la geochimie. La prospection geophysique apporte des precisions sur les structures tectoniques auxquelles sont lies les gisements d'uranium fran is et sur la notion de zones favorables. Aux methodes indirectes de la geophysique, la prospection geochimique ajoute des precisions sur la repartition de l'uranium en traces dans les sols, cette methode est directe et specifique. Le dosage de l'uranium dans les eaux et les alluvions trouve son application dans la prospection de reconnaissance. (auteur)

Uranium project. Geochemistry prospection

International Nuclear Information System (INIS)

Lambert, J.

1983-01-01

Geochemistry studies the distribution of the chemicals elements in the terrestrial crust and its ways to migrate. The terminology used in this report is the following one: 1) Principles of the prospection geochemistry 2) Stages of the prospection geochemistry 3)utility of the prospection geochemistry 4) geochemistry of uranium 5) procedures used within the framework of uranium project 6) Average available 7) Selection of the zones of prospection geochemistry 8) Stages of the prospection, Sample preparation and analisis 9) Presentation of the results

Future directions in geobiology and low-temperature geochemistry

Science.gov (United States)

Freeman, Katherine H.; Goldhaber, M.B.

2011-01-01

Humanity is confronted with an enormous challenge, as succinctly stated by the late Steven Schneider (2001; quoted by Jantzen 2004*): “Humans are forcing the Earth’s environmental systems to change at a rate that is more advanced than their knowledge of the consequences.” Geobiologists and low-temperature geochemists characterize material from the lithosphere, hydrosphere, atmosphere, and biosphere to understand processes operating within and between these components of the Earth system from the atomic to the planetary scale. For this reason, the interwoven disciplines of geobiology and low-temperature geochemistry are central to understanding and ultimately predicting the behavior of these life-sustaining systems. We present here comments and recommendations from the participants of a workshop entitled “Future Directions in Geobiology and Low-Temperature Geochemistry,” hosted by the Carnegie Institution of Washington, Geophysical Laboratory, Washington, DC, on 27–28 August 2010. The goal of the workshop was to suggest ways to leverage the vast intellectual and analytical capabilities of our diverse scientific community to characterize the Earth’s past, present, and future geochemical habitat as we enter the second decade of what E. O. Wilson dubbed “the century of the environment.”

Some geomechanical aspects of geological CO2 sequestration

NARCIS (Netherlands)

Orlic, B.

2008-01-01

Reservoir depletion and subsequent CO 2 injection into the depleted geological reservoir induce stress changes that may mechanically damage top seal and wells, or trigger existing faults, creating the leakage pathways for CO 2 escape from the reservoir. The role of geomechanics is to assess the

Some geomechanical aspects of geological CO2 sequestration

NARCIS (Netherlands)

Orlic, B.

2009-01-01

Reservoir depletion and subsequent CO2 injection into the depleted geological reservoir induce stress changes that may mechanically damage top seal and wells, or trigger existing faults, creating the leakage pathways for CO2 escape from the reservoir. The role of geomechanics is to assess the

Geomechanics of clays for radioactive waste disposal

International Nuclear Information System (INIS)

Come, B.

1989-01-01

Clay formations have been studied for many years in the European Community as potential disposal media for radioactive waste. This document brings together results of on-going research about the geomechanical behaviour of natural clay bodies, at normal and elevated temperatures. The work is carried out within the third Community R and D programme on Management and storage of radioactive waste

Problems of applied geochemistry

Energy Technology Data Exchange (ETDEWEB)

Ovchinnikov, L N

1983-01-01

The concept of applied geochemistry was introduced for the first time by A. Ye. Fersman. He linked the branched and complicated questions of geochemistry with specific problems of developing the mineral and raw material base of our country. Geochemical prospecting and geochemistry of mineral raw materials are the most important sections of applied geochemistry. This now allows us the right to view applied geochemistry as a sector of science which applies geochemical methodology, set of geochemical methods of analysis, synthesis, geological interpretation of data based on laws governing theoretical geochemistry to the solution of different tasks of geology, petrology, tectonics, stratigraphy, science of minerals and other geological sciences, and also the technology of mineral raw materials, interrelationships of man and nature (ecogeochemistry, technogeochemistry, agrogeochemistry). The main problem of applied geochemistry, geochemistry of ore fields is the prehistory of ore formation. This is especially important for metallogenic and forecasting constructions, for an understanding of the reasons for the development of fields and the detection of laws governing their distribution, their genetic links with the general geological processes and the products of these processes.

Use of the radon gas as a natural geophysical tracer

International Nuclear Information System (INIS)

Pena, P.; Balcazar, M.; Flores R, J.H.; Lopez M, A.

2006-01-01

In this work it is denoted the applications of the radon gas like a natural geophysical radiotracer in the different branches of the Earth Sciences (Geology, geophysics and geochemistry). It importance resides in its employment like one additional tool to register the possible occurrence of seismic events by means of radon anomalies that are presented in land movements (volcanic eruptions and presence of geothermal areas), as well as its potential in environmental works whose purpose is the evaluation of the feather of contamination in the underground water and the porous media for spills of hydrocarbons. The measurement techniques to determine the concentration of radon was carried out by means of Solid Detectors of Nuclear tracks, as well as by Liquid scintillation, Clipperton, Honeywell, AlphaGUARD. The towns where these techniques its were applied were: Mexico City, Estado de Mexico (Toluca, ININ), Jalisco (The Spring), Guerrero coast. (Author)

Modeling reservoir geomechanics using discrete element method : Application to reservoir monitoring

Energy Technology Data Exchange (ETDEWEB)

Alassi, Haitham Tayseer

2008-09-15

Understanding reservoir geomechanical behavior is becoming more and more important for the petroleum industry. Reservoir compaction, which may result in surface subsidence and fault reactivation, occurs during reservoir depletion. Stress changes and possible fracture development inside and outside a depleting reservoir can be monitored using time-lapse (so-called '4D') seismic and/or passive seismic, and this can give valuable information about the conditions of a given reservoir during production. In this study we will focus on using the (particle-based) Discrete Element Method (DEM) to model reservoir geomechanical behavior during depletion and fluid injection. We show in this study that DEM can be used in modeling reservoir geomechanical behavior by comparing results obtained from DEM to those obtained from analytical solutions. The match of the displacement field between DEM and the analytical solution is good, however there is mismatch of the stress field which is related to the way stress is measured in DEM. A good match is however obtained by measuring the stress field carefully. We also use DEM to model reservoir geomechanical behavior beyond the elasticity limit where fractures can develop and faults can reactivate. A general technique has been developed to relate DEM parameters to rock properties. This is necessary in order to use correct reservoir geomechanical properties during modeling. For any type of particle packing there is a limitation that the maximum ratio between P- and S-wave velocity Vp/Vs that can be modeled is 3 . The static behavior for a loose packing is different from the dynamic behavior. Empirical relations are needed for the static behavior based on numerical test observations. The dynamic behavior for both dense and loose packing can be given by analytical relations. Cosserat continuum theory is needed to derive relations for Vp and Vs. It is shown that by constraining the particle rotation, the S-wave velocity can be

Assessment of geomechanical properties of intact Opalinus Clay - Expert report

International Nuclear Information System (INIS)

Amann, F.; Vogelhuber, M.

2015-11-01

This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI presents an expert report published on the assessment of the geomechanical properties of intact Opalinus Clay. This review report addresses the conceptual constitutive framework for repositories in Opalinus Clay. The author addresses the geomechanical fundamentals that are necessary in order to adequately judge experiments on intact Opalinus Clay and the interpretation of the results. The report assesses in detail the various test series on intact Opalinus Clay carried out along with the interpretations made by experts and NAGRA. Further assessments are quoted including those on sample geometries tested, effective strength properties, undrained shear strength properties and elastic properties. The results of work done by other experts are also presented and discussed. The report is completed with a list of relevant literature

Assessment of geomechanical properties of intact Opalinus Clay - Expert report

Energy Technology Data Exchange (ETDEWEB)

Amann, F. [Eidgenössische Technische Hochschule ETHZ, Zürich (Switzerland); Vogelhuber, M. [Dr. von Moos AG, Geotechnisches Büro, Zürich (Switzerland)

2015-11-15

This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI presents an expert report published on the assessment of the geomechanical properties of intact Opalinus Clay. This review report addresses the conceptual constitutive framework for repositories in Opalinus Clay. The author addresses the geomechanical fundamentals that are necessary in order to adequately judge experiments on intact Opalinus Clay and the interpretation of the results. The report assesses in detail the various test series on intact Opalinus Clay carried out along with the interpretations made by experts and NAGRA. Further assessments are quoted including those on sample geometries tested, effective strength properties, undrained shear strength properties and elastic properties. The results of work done by other experts are also presented and discussed. The report is completed with a list of relevant literature.

Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

Science.gov (United States)

Rutqvist, J.; Moridis, G.J.; Grover, T.; Collett, T.

2009-01-01

In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900??m at the Mallik site and 600??m at the Mount Elbert site. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure.

Proceedings of the 3. Brazilian Congress on Geochemistry; 1. Congress on Geochemistry from Portuguese Language Countries - Abstracts

International Nuclear Information System (INIS)

1991-01-01

This congress presents topics about geochemistry, including litho-geochemistry, environmental geochemistry, hydro-geochemistry and surface geochemistry. Works on geochronology and nuclear methods in rocks and minerals are also described. (C.G.C.)

Stress determination and geomechanical stability analysis of an oil ...

Indian Academy of Sciences (India)

Practical data including geomechanical parameters along with drilling data from one of Iranian oilfields, Mansouri-54 well have been utilized in this analysis. in situ stress was determined using stress polygon method and conducting hydraulic fracturing data in the field. Analytical solution using the Mogi–Coulomb and the ...

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

Science.gov (United States)

,

2014-01-01

This report contains three contractor reports and data files for an airborne electromagnetic survey flown from June 28 to July 7, 2010. The first report; “SkyTEM Survey: Nebraska, USA, Data” describes data aquisition and processing from a time-domain electromagnetic and magnetic survey performed by SkyTEM Canada, Inc. (the North American SkyTEM subsidiary), in western Nebraska, USA. Digital data for this report are given in Appendix 1. The airborne geophysical data from the SkyTEM survey subsequently were processed and inverted by Aarhus Geophysics ApS, Aarhus, Denmark, to produce resistivity depth sections along each flight line. The result of that processing is described in two reports presented in Appendix 2, “Processing and inversion of SkyTEM data from USGS Area UTM–13” and “Processing and inversion of SkyTEM data from USGS Area UTM–14.” Funding for these surveys was provided by the North Platte Natural Resources District, the South Platte Natural Resources District, and the Twin Platte Natural Resources District, in Scottsbluff, Sidney, and North Platte, Nebraska, respectively. Any additional information concerning the geophysical data may be obtained from the U.S. Geological Survey Crustal Geophysics and Geochemistry Science Center, Denver Colorado.

Geomechanical and petrophysical properties of mudrocks: introduction

OpenAIRE

Rutter, Ernest

2017-01-01

Mudstones (shales) are of particular importance as the source rocks for oil and gas, and increasingly so as the reservoirs for unconventional hydrocarbons. They are also the most common sedimentary rocks on Earth, and, hence, are frequently encountered in excavations and foundations for buildings. These factors point to a pressing need to develop an increased fundamental understanding of their geomechanical and petrophysical properties. The mineral content of mudstones has a dominant effect o...

Geological Geophysical and structural studies in Mina Ratones (Pluton de Albala)

International Nuclear Information System (INIS)

Perez-Estaun, A.; Carbonell, R.; Marti, D.; Flecha, I.; Escuder Viruete, J.

2002-01-01

Mina Ratones environmental restoration project included petrological, structural,geophysical, hydrogeological and hydrogeochemical studies. The main objective of the geologic-structural and geophysical studies was the Albala granite structural characterization around the Mina Ratones uranium mine. The location of facies, fault zones (faults and dykes) as well as the distribution of some physical properties inside the rock massif was obtained for a granitic black of 900, 500, and 500 m. The geologic-structural and geophysical techniques applied to Mina Ratones provided a multidisciplinary approach for high resolution characterization of rock massif, and the structures potentially containing fluids,able to be applied to the hydrogeological modelling to a particular area. Geological studies included a detailed structural mapping of the area surrounding the mine (1:5,000 scale), the geometric, kinematics, and dynamics analysis of fractures of all scales, the petrology and geochemistry of fault rocks and altered areas surrounding fractures, and the microstructural studies of samples from surface and core lags. The construction of geostatistical models in two and three dimensions had helped to characterize the Mina Ratones rock massif showing the spatial distribution of fault zones, fracture intensity, granite composition heterogeneities, fluid-rock interaction zones, and physical properties. (Author)

Evaluation of geophysical techniques for identifying fractures in program wells in Deaf Smith County, Texas: Revision 1, Topical report

International Nuclear Information System (INIS)

Gillespie, R.P.; Siminitz, P.C.

1987-08-01

Quantitative information about the presence and orientation of fractures is essential for the understanding of the geomechanical and geohydrological behavior of rocks. This report evaluates various borehole geophysical techniques for characterizing fractures in three Civilian Radioactive Waste Management (CRWM) Program test wells in the Palo Duro Basin in Deaf Smith County, Texas. Emphasis has been placed on the Schlumberger Fracture Identification Log (FIL) which detects vertical fractures and provides data for calculation of orientation. Depths of FIL anomalies were compared to available core. It was found that the application of FIL results to characterize fracture frequency or orientation is inappropriate at this time. The uncertainties associated with the FIL information render the information unreliable. No geophysical logging tool appears to unequivocally determine the location and orientation of fractures in a borehole. Geologic mapping of the exploratory shafts will ultimately provide the best data on fracture frequency and orientation at the proposed repository site. 22 refs., 6 figs., 3 tabs

Geomechanical time series and its singularity spectrum analysis

Czech Academy of Sciences Publication Activity Database

Lyubushin, Alexei A.; Kaláb, Zdeněk; Lednická, Markéta

2012-01-01

Roč. 47, č. 1 (2012), s. 69-77 ISSN 1217-8977 R&D Projects: GA ČR GA105/09/0089 Institutional research plan: CEZ:AV0Z30860518 Keywords : geomechanical time series * singularity spectrum * time series segmentation * laser distance meter Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.347, year: 2012 http://www.akademiai.com/content/88v4027758382225/fulltext.pdf

PREFACE: International Symposium on Geohazards and Geomechanics (ISGG2015)

Science.gov (United States)

Utili, S.

2015-09-01

These Conference Proceedings contain the full papers in electronic format of the International Symposium on 'Geohazards and Geomechanics', held at University of Warwick, UK, on September 10-11, 2015. The Symposium brings together the complementary expertise of world leading groups carrying out research on the engineering assessment, prevention and mitigation of geohazards. A total of 58 papers, including 8 keynote lectures cover phenomena such as landslide initiation and propagation, debris flow, rockfalls, soil liquefaction, ground improvement, hazard zonation, risk mapping, floods and gas and leachates. The techniques reported in the papers to investigate geohazards involve numerical modeling (finite element method, discrete element method, material point method, meshless methods and particle methods), experimentation (laboratory experiments, centrifuge tests and field monitoring) and analytical simplified techniques. All the contributions in this volume have been peered reviewed according to rigorous international standards. However the authors take full responsibility for the content of their papers. Agreements are in place for the edition of a special issue dedicated to the Symposium in three international journals: Engineering Geology, Computational Particle Mechanics and International Journal of Geohazards and Environment. Authors of selected papers will be invited to submit an extended version of their work to these Journals that will independently assess the papers. The Symposium is supported by the Technical Committee 'Geo-mechanics from Micro to Macro' (TC105) of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE), 'Slope Stability in Engineering Practice' (TC208), 'Forensic Geotechnical Engineering' (TC302), the British Geotechnical Association and the EU FP7 IRSES project 'Geohazards and Geomechanics'. Also the organizers would like to thank all authors and their supporting institutions for their contributions. For any

Geochemical and geomechanical solid-solutions interactions in unsaturated media. Prospects for the storage of nuclear waste

International Nuclear Information System (INIS)

Bouzid, M.

2010-01-01

Porous materials, especially the unsaturated ones, are complex systems in which several physicochemical parameters interact (eg relative humidity, T C, pore solution composition, geometry of the pore network). The precipitation of secondary phases inside and the associated changes (e.g. topology of the porous spaces) are important to understand for several applied topics: civil engineering, soil science or geology of deep wastes disposal. This experimental work was undertaken to better understand the mechanisms linking geochemical phase transitions and physicochemical properties of multiphasic porous media. The precipitation of salts in porous synthetic materials allowed us to identify two types of geochemistry-geomechanics coupling: the crystallization pressure (compression phenomenon, already known in the literature), and the capillary traction. These secondary precipitates are also responsible for a porous networks heterogenization which modifies the transfer functions. But we also show that the portions of liquid may be isolated by salts 'corks' and thus develop new thermochemical properties. In particular, we have observed cavitation events in some of these occluded solutions which indicate that they underwent a metastable superheated state. Finally, differential extraction experiments showed that the solubility changes with the pore size, and an interpretation based on pore geometry (solid curvature) has been proposed. Some evidence that these phenomena may actually be active in natural processes were collected, and this extension to the natural environment must now be treated extensively. (authors)

Geochemistry Review Panel report on the SRP geochemistry program and draft geochemistry summary program plan (May, 1986) and discussion of panel recommendations

International Nuclear Information System (INIS)

1986-12-01

The Geochemistry Review Panel (GRP) was established by the Salt Repository Project Office (SRPO) to help evaluate geochemistry-related issues in the US Department of Energy's nuclear waste repository program. The May 1986 meeting of the GRP reviewed the Salt Repository Program (SRP) geochemistry program developed by the Office of Nuclear Waste Isolation (ONWI). This program is described in the Draft Geochemistry Plan of April 9, 1986. This report documents the GRP's comments and recommendations on this subject and the ONWI responses to the specific points raised by the GRP

Geomechanical modeling of the Steinernase landslide (Switzerland)

OpenAIRE

Laloui, Lyesse; Ferrari, Alessio; Bonnard, Christophe

2009-01-01

A geomechanical model was developed to analyse the behaviour of a natural slope located on the bank of the Rhine River between the towns of Stein and Mumpf in Switzerland. The slope is affected by a landslide and three strategic infrastructure assets are located at its toe. An intense monitoring campaign made it possible to identify pore water pressure evolution as the main cause for movement accelerations and to detect the presence of a multiple slip surface system. Advanced coupled finite e...

Geomechanical monitoring system at the Waste Isolation Pilot Plant, Carlsbad, New Mexico

International Nuclear Information System (INIS)

Francke, J.L.; Cook, R.F.; Carrasco, R.C.

1993-01-01

This paper describes in detail the geomechanical instrumentation system and the data base that has been established from the geomechanical monitoring program. In addition, it describes the quality assurance and control measures that are in place to ensure that the data from the underground is accurate, traceable, and defensible. The system is installed at the Waste Isolation Pilot Plant in Carlsbad, New Mexico. This facility is being developed for the disposal of transuranic nuclear wastes in underground excavations in salt 2150 feet below the surface. The purpose of the instrumentation system is to monitor the deformations and stress changes that are occurring in the rock with time. This information is needed to routinely assess conditions in the facility and to ensure that safe operating conditions are maintained

Geomechanical Performance of Hydrate-Bearing Sediment in Offshore Environments

Energy Technology Data Exchange (ETDEWEB)

Stephen Holditch; Tad Patzek; Jonny Rutqvist; George Moridis; Richard Plumb

2008-03-31

The objective of this multi-year, multi-institutional research project was to develop the knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate-bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus was on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. We have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. We also investigated the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. The objective of the UC Berkeley work was to develop a grain-scale model of hydrate-bearing sediments. Hydrate dissociation alters the strength of HBS. In particular, transformation of hydrate clusters into gas and liquid water weakens the skeleton and, simultaneously, reduces the effective stress by increasing the pore pressure. The large-scale objective of the study is evaluation of geomechanical stability of offshore oil and gas production infrastructure. At Lawrence Berkeley National Laboratory (LBNL), we have developed the numerical model TOUGH + Hydrate + FLAC3D to evaluate how the formation and disassociation of hydrates in seafloor sediments affects seafloor stability. Several technical papers were published using results from this model. LBNL also developed laboratory equipment and methods to produce realistic laboratory samples of sediments containing gas hydrates so that mechanical properties could be measured in the laboratory. These properties are required to run TOUGH + Hydrate + FLAC3D to evaluate seafloor stability issues. At Texas A&M University we performed a detailed literature review to determine what gas hydrate formation properties had been measured and reported in the literature. We

Geomechanics considerations for through-and near-salt well design

International Nuclear Information System (INIS)

Willson, S.M.; Fredrich, Joanne T.

2005-01-01

Over the next decade a significant amount of exploration and new field developments will take place in salt provinces around the world - in the deepwater Gulf of Mexico, and offshore Angola, Brazil, and North and West Africa. Salt formations provide both opportunities and challenges to the design and construction of the often complex wells to be drilled in these locations. An overview of the many geomechanical considerations necessary to ensure successful well construction when drilling in through-, sub- and near-salt environments is presented. The structural styles of deformed sediments adjacent to salt, combined with stress perturbations caused by the presence of salt, are used to assess the risk of encountering zones that might cause wellbore instability or lost-circulation problems. Well design examples are provided that show how near- and through-salt uncertainties may be included within a geomechanical well design for required mud weights while drilling. Salt is found in many hydrocarbon basins around the world. Significant deposits exist in the Gulf of Mexico (GoM), offshore West Africa and Brazil, in the Southern North Sea, Egypt, and the Middle East (Figure 1(1)). In deep water offshore North America, the GoM and offshore Nova Scotia (NE Canada) are notable areas of current oil and gas exploration and production. Significant exploration activity is also targeting areas offshore Angola and Brazil. The extent of deepwater exploration in the GoM is illustrated in Figure 2 that shows the steady march into deeper water, together with a focusing of efforts in the Sigsbee Escarpment areas of Green Canyon, Walker Ridge and Atwater Valley. The deepest wells in the GoM are reaching true vertical depths of up to 32,000 feet, with maximum-recorded downhole pressures in excess of 26,000 psi and bottomhole temperatures in excess of 400 F. Such wells may penetrate considerable thicknesses of salt - up to 20,000 feet of salt is not unheard of. With substantial discoveries

Coupled processes affecting the performance of a nuclear waste repository. Proceedings

International Nuclear Information System (INIS)

Tsang, C.F.

1985-09-01

Contributed papers were in the following subject areas: geochemistry, geohydrology, and geomechanics. In addition to the contributed papers, current field projects were reviewed. Individual papers were processed separately. (LM)

Clay shale as host rock. A geomechanical contribution about Opalinus clay

International Nuclear Information System (INIS)

Lempp, Christof; Menezes, Flora; Sachwitz, Simon

2016-01-01

The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

Geomechanical characterization of volcanic rocks using empirical systems and data mining techniques

Directory of Open Access Journals (Sweden)

T. Miranda

2018-02-01

Full Text Available This paper tries to characterize volcanic rocks through the development and application of an empirical geomechanical system. Geotechnical information was collected from the samples from several Atlantic Ocean islands including Madeira, Azores and Canarias archipelagos. An empirical rock classification system termed as the volcanic rock system (VRS is developed and presented in detail. Results using the VRS are compared with those obtained using the traditional rock mass rating (RMR system. Data mining (DM techniques are applied to a database of volcanic rock geomechanical information from the islands. Different algorithms were developed and consequently approaches were followed for predicting rock mass classes using the VRS and RMR classification systems. Finally, some conclusions are drawn with emphasis on the fact that a better performance was achieved using attributes from VRS.

Geomechanical properties of lime stabilized clayey sands

International Nuclear Information System (INIS)

Arabani, M.; Karami, M. Veis

2007-01-01

Clayey sands that have low plasticity, low compressibility and high strength under loads, are suitable as a base material for any engineering construction projects as well as for roads and building construction. Decrease of plasticity and compressibility as well as increase in strength of these materials can be obtained by many different methods. Of these methods, lime stabilization is a common, applicable, and easy to use approach that can improve geomechanical and geotechnical properties of clayey sand fills. In this study some important geomechanical properties and geotechnical properties of clayey sands including compressive strength, CBR and elastic plastic behavior are investigated. A range of gradations representative of those gradations found in situ in the north of Iran were selected for testing and samples were artificially rebuilt in the laboratory. The mixes were then stabilized with hydrated lime and cured. Different mechanical tests were performed on mature materials. The stress-strain behavior of lime-stabilized mixes was plotted and a parabolic function was used to estimate the trend of stress-strain behavior. The data show that there is a correlation among the results of uniaxial load test, tensile strength, and CBR of the tested specimens. Also, results of the unconfined compression test and the indirect tensile strength test show that an increase in clay content up to a certain percent, in the clay-sand fills, tends to increase the strength of the materials in compression as well as in tension. (author)

Critical zone architecture and processes: a geophysical perspective

Science.gov (United States)

Holbrook, W. S.

2016-12-01

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

A new approach to determine geomechanical parameters of Vertical Transverse Isotropic media using VSP data

Science.gov (United States)

Gholami, Raoof; Moradzadeh, Ali; Rasouli, Vamegh; Hanachi, Javid

2014-12-01

Conventionally, high frequency Dipole Shear sonic Imager (DSI) logs are used for anisotropic modeling where fast and slow shear wave's velocities are required. However, the results obtained from a DSI log are restricted to a specific and possibly short interval of the wellbore. The aims of this paper are to use Vertical Seismic Profile (VSP) data and show its application in geomechanical analysis of subsurface layers under anisotropic condition. After processing and separating upgoing and downgoing P- and S-waves, a methodology based Vertical Transverse Isotropic (VTI) condition was presented to determine elastic stiffness parameters. Having stiffness parameters determined, elastic modulus, strength and in-situ stress parameters were estimated and calibrated against the field and core sample data. Although the VSP based geomechanical parameters were calibrated against the real field data, the accuracy of the method cannot be as much as that of the well logs. However, the method presented in this paper may become a very good asset for geomechanical evaluation of the intervals where well log data are not available.

Effects of Geomechanical Mechanism on the Gas Production Behavior: A Simulation Study of Class-3 Type Four-Way-Closure Ridge Hydrate Deposit Offshore Southwestern Taiwan

Science.gov (United States)

Wu, Cheng-Yueh; Chiu, Yung-Cheng; Huang, Yi-Jyun; Hsieh, Bieng-Zih

2017-04-01

geophysical studies and the geo-mechanical data were analogized from Japan's hydrate production case. The first step for the geological modelling was to digitize the structure map of FWC Ridge and built a grid system for the reservoir. The formation parameters, such as formation thickness, porosity and permeability, the phase behavior parameters, rock-fluid parameters, initial conditions (including formation pressure, temperature and hydrate saturation), geo-mechanical parameters were assigned into each grid. In this case we used a horizontal well with specific operating conditions to produce water and dissociated gas from the reservoir. The sensitivity analyses on geological and geo-mechanical parameters were conducted in this study. The case of different pressure drop showed that the recovery factor (RF) was 2.50%, 13.50% and 20.47% when the pressure drop of 60%, 70% and 75% from the initial reservoir pressure was used respectively. Based on the case of pressure drop of 75% (from the initial reservoir pressure), the RF was 35.13%, 25.9%, 20.47% and 16.65% when the initial hydrate saturation of 30%, 40%, 50% and 60% was assumed respectively. The greater formation permeability, the better gas recovery. The capillary pressure had a minor affection on the gas production in this case study. The best well location was at the upper layer because of the gravity effect. For the effects of the geo-mechanics, we observed that the rock mechanisms had impacts on the final cumulative gas production. The larger the Young's Modulus and the smaller the Poisson's Ratio, the smaller the subsidence on the seabed. Our simulation results showed that the seabed subsidence in FWC Ridge was about 1 meter during the production period.

Multiple intersecting cohesive discontinuities in 3D reservoir geomechanics

OpenAIRE

Das, K. C.; Sandha, S.S.; Carol, Ignacio; Vargas, P.E.; Gonzalez, Nubia Aurora; Rodrigues, E.; Segura Segarra, José María; Lakshmikantha, Ramasesha Mookanahallipatna; Mello,, U.

2013-01-01

Reservoir Geomechanics is playing an increasingly important role in developing and producing hydrocarbon reserves. One of the main challenges in reservoir modeling is accurate and efficient simulation of arbitrary intersecting faults. In this paper, we propose a new formulation to model multiple intersecting cohesive discontinuities (faults) in reservoirs using the XFEM framework. This formulation involves construction of enrichment functions and computation of stiffness sub-matrices for bulk...

COSA II Further benchmark exercises to compare geomechanical computer codes for salt

International Nuclear Information System (INIS)

Lowe, M.J.S.; Knowles, N.C.

1989-01-01

Project COSA (COmputer COdes COmparison for SAlt) was a benchmarking exercise involving the numerical modelling of the geomechanical behaviour of heated rock salt. Its main objective was to assess the current European capability to predict the geomechanical behaviour of salt, in the context of the disposal of heat-producing radioactive waste in salt formations. Twelve organisations participated in the exercise in which their solutions to a number of benchmark problems were compared. The project was organised in two distinct phases: The first, from 1984-1986, concentrated on the verification of the computer codes. The second, from 1986-1988 progressed to validation, using three in-situ experiments at the Asse research facility in West Germany as a basis for comparison. This document reports the activities of the second phase of the project and presents the results, assessments and conclusions

An overview of iterative coupling between geomechanical deformation and reservoir flow

International Nuclear Information System (INIS)

Tran, D.; Nghiem, L.; Buchanan, L.

2005-01-01

The coupling of a reservoir simulator to a geomechanics module has been widely applied in the petroleum industry. In a traditional reservoir simulator, subsidence can be estimated by a relatively simple formula. In a coupled simulator, flow is strongly affected by stresses and strains through porosity. Stress-dependence is ignored completely in conventional simulators, and solutions obtained from them cannot give accurate results if a stress sensitive reservoir is under consideration. In addition, thermal stresses cannot be accounted for. An iterative coupling method was presented. The basic equations for fluid flow in a porous medium consist of the equation of mass conservation, the equation of energy conservation, Darcy's law and equations of state depicting fluid characteristics. A continuum approach was used to develop the conservative equations. Material was assumed to be homogenous, isotropic and symmetric. Three test examples were used to illustrate the validity of geomechanics in reservoir simulation. The first example illustrated the difference in heave when a linear thermo-elastic constitutive model and a thermo-elastoplastic model were used. In the second example, a plastic cap model and a no-cap model were used to illustrate differences in porosity calculations. The 2 examples demonstrated that displacements and porosity calculations depend on the stress response and on the constitutive law of a material. In the third example a pseudo dilation-recompaction model showed a displacement calculation that was comparable with calculations obtained with 2-way coupling. The example illustrated the application of one-way coupling in scenarios where rigorous geomechanics calculations of subsidence are performed without the constraint of feeding back the information to a reservoir simulator. 22 refs., 13 figs

Earth Sciences Division Research Summaries 2002-2003

International Nuclear Information System (INIS)

Bodvarsson, G.S.

2003-01-01

Research in earth and atmospheric sciences is becoming increasingly important in light of the energy, climate change, and environmental issues facing the United States and the world. The development of new energy resources other than hydrocarbons and the safe disposal of nuclear waste and greenhouse gases (such as carbon dioxide and methane) are critical to the future energy needs and environmental safety of this planet. In addition, the cleanup of many contaminated sites in the U.S., along with the preservation and management of our water supply, remain key challenges for us as well as future generations. Addressing these energy, climate change, and environmental issues requires the timely integration of earth sciences' disciplines (such as geology, hydrology, oceanography, climatology, geophysics, geochemistry, geomechanics, ecology, and environmental sciences). This integration will involve focusing on fundamental crosscutting concerns that are common to many of these issues. A primary focus will be the characterization, imaging, and manipulation of fluids in the earth. Such capabilities are critical to many DOE applications, from environmental restoration to energy extraction and optimization. The Earth Sciences Division (ESD) of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) is currently addressing many of the key technical issues described above. In this document, we present summaries of many of our current research projects. While it is not a complete accounting, it is representative of the nature and breadth of our research effort. We are proud of our scientific efforts, and we hope that you will find our research useful and exciting. Any comments on our research are appreciated and can be sent to me personally. This report is divided into five sections that correspond to the major research programs in the Earth Sciences Division: (1) Fundamental and Exploratory Research; (2) Nuclear Waste; (3) Energy Resources; (4) Environmental

Earth Sciences Division Research Summaries 2002-2003

Energy Technology Data Exchange (ETDEWEB)

Bodvarsson, G.S.

2003-11-01

Research in earth and atmospheric sciences is becoming increasingly important in light of the energy, climate change, and environmental issues facing the United States and the world. The development of new energy resources other than hydrocarbons and the safe disposal of nuclear waste and greenhouse gases (such as carbon dioxide and methane) are critical to the future energy needs and environmental safety of this planet. In addition, the cleanup of many contaminated sites in the U.S., along with the preservation and management of our water supply, remain key challenges for us as well as future generations. Addressing these energy, climate change, and environmental issues requires the timely integration of earth sciences' disciplines (such as geology, hydrology, oceanography, climatology, geophysics, geochemistry, geomechanics, ecology, and environmental sciences). This integration will involve focusing on fundamental crosscutting concerns that are common to many of these issues. A primary focus will be the characterization, imaging, and manipulation of fluids in the earth. Such capabilities are critical to many DOE applications, from environmental restoration to energy extraction and optimization. The Earth Sciences Division (ESD) of the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) is currently addressing many of the key technical issues described above. In this document, we present summaries of many of our current research projects. While it is not a complete accounting, it is representative of the nature and breadth of our research effort. We are proud of our scientific efforts, and we hope that you will find our research useful and exciting. Any comments on our research are appreciated and can be sent to me personally. This report is divided into five sections that correspond to the major research programs in the Earth Sciences Division: (1) Fundamental and Exploratory Research; (2) Nuclear Waste; (3) Energy Resources; (4

The Conterminous United States Mineral Appraisal Program; background information to accompany folio of geologic, geochemical, geophysical, and mineral resources maps of the Tonopah 1 by 2 degree Quadrangle, Nevada

Science.gov (United States)

John, David A.; Nash, J.T.; Plouff, Donald; Whitebread, D.H.

1991-01-01

The Tonopah 1 ? by 2 ? quadrangle in south-central Nevada was studied by an interdisciplinary research team to appraise its mineral resources. The appraisal is based on geological, geochemical, and geophysical field and laboratory investigations, the results of which are published as a folio of maps, figures, and tables, with accompanying discussions. This circular provides background information on the investigations and integrates the information presented in the folio. The selected bibliography lists references to the geology, geochemistry, geophysics, and mineral deposits of the Tonopah 1 ? by 2 ? quadrangle.

Key Geomechanics Issues at the Waste Isolation Pilot Plant Geomechanics

International Nuclear Information System (INIS)

HANSEN, FRANCIS D.

1999-01-01

Mechanical and hydrological properties of rock salt provide excellent bases for geological isolation of hazardous materials. Regulatory compliance determinations for the Waste Isolation Pilot Plant (WIPP) stand as testament to the widely held conclusion that salt provides excellent isolation properties. The WIPP saga began in the 1950s when the U.S. National Academy of Sciences (NAS) recommended a salt vault as a promising solution to the national problem of nuclear waste disposal. For over 20 years, the Scientific basis for the NAS recommendation has been fortified by Sandia National Laboratories through a series of large scale field tests and laboratory investigations of salt properties. These scientific investigations helped develop a comprehensive understanding of salt's 4 reformational behavior over an applicable range of stresses and temperatures. Sophisticated constitutive modeling, validated through underground testing, provides the computational ability to model long-term behavior of repository configurations. In concert with advancement of the mechanical models, fluid flow measurements showed not only that the evaporite lithology was essentially impermeable but that the WIPP setting was hydrologically inactive. Favorable mechanical properties ensure isolation of materials placed in a salt geological setting. Key areas of the geomechanics investigations leading to the certification of WIPP are in situ experiments, laboratory tests, and shaft seal design

Long-term Geomechanical Observation in the Jeroným Mine

Czech Academy of Sciences Publication Activity Database

Kaláb, Zdeněk; Lednická, Markéta

2016-01-01

Roč. 64, č. 5 (2016), s. 1513-1524 ISSN 1895-7455 R&D Projects: GA ČR GA105/09/0089 Institutional support: RVO:68145535 Keywords : abandoned mine * geomechanical observation * movements along fractures * stress tensor changes * mine water table fluctuation Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.968, year: 2016 http://agp.igf.edu.pl/files/64/5/Kalab-Lednicka.pdf

Development of a dynamic coupled hydro-geomechanical code and its application to induced seismicity

Science.gov (United States)

Miah, Md Mamun

This research describes the importance of a hydro-geomechanical coupling in the geologic sub-surface environment from fluid injection at geothermal plants, large-scale geological CO2 sequestration for climate mitigation, enhanced oil recovery, and hydraulic fracturing during wells construction in the oil and gas industries. A sequential computational code is developed to capture the multiphysics interaction behavior by linking a flow simulation code TOUGH2 and a geomechanics modeling code PyLith. Numerical formulation of each code is discussed to demonstrate their modeling capabilities. The computational framework involves sequential coupling, and solution of two sub-problems- fluid flow through fractured and porous media and reservoir geomechanics. For each time step of flow calculation, pressure field is passed to the geomechanics code to compute effective stress field and fault slips. A simplified permeability model is implemented in the code that accounts for the permeability of porous and saturated rocks subject to confining stresses. The accuracy of the TOUGH-PyLith coupled simulator is tested by simulating Terzaghi's 1D consolidation problem. The modeling capability of coupled poroelasticity is validated by benchmarking it against Mandel's problem. The code is used to simulate both quasi-static and dynamic earthquake nucleation and slip distribution on a fault from the combined effect of far field tectonic loading and fluid injection by using an appropriate fault constitutive friction model. Results from the quasi-static induced earthquake simulations show a delayed response in earthquake nucleation. This is attributed to the increased total stress in the domain and not accounting for pressure on the fault. However, this issue is resolved in the final chapter in simulating a single event earthquake dynamic rupture. Simulation results show that fluid pressure has a positive effect on slip nucleation and subsequent crack propagation. This is confirmed by

Multi-Site Application of the Geomechanical Approach for Natural Fracture Exploration

Energy Technology Data Exchange (ETDEWEB)

R. L. Billingsley; V. Kuuskraa

2006-03-31

In order to predict the nature and distribution of natural fracturing, Advanced Resources Inc. (ARI) incorporated concepts of rock mechanics, geologic history, and local geology into a geomechanical approach for natural fracture prediction within mildly deformed, tight (low-permeability) gas reservoirs. Under the auspices of this project, ARI utilized and refined this approach in tight gas reservoir characterization and exploratory activities in three basins: the Piceance, Wind River and the Anadarko. The primary focus of this report is the knowledge gained on natural fractural prediction along with practical applications for enhancing gas recovery and commerciality. Of importance to tight formation gas production are two broad categories of natural fractures: (1) shear related natural fractures and (2) extensional (opening mode) natural fractures. While arising from different origins this natural fracture type differentiation based on morphology is sometimes inter related. Predicting fracture distribution successfully is largely a function of collecting and understanding the available relevant data in conjunction with a methodology appropriate to the fracture origin. Initially ARI envisioned the geomechanical approach to natural fracture prediction as the use of elastic rock mechanics methods to project the nature and distribution of natural fracturing within mildly deformed, tight (low permeability) gas reservoirs. Technical issues and inconsistencies during the project prompted re-evaluation of these initial assumptions. ARI's philosophy for the geomechanical tools was one of heuristic development through field site testing and iterative enhancements to make it a better tool. The technology and underlying concepts were refined considerably during the course of the project. As with any new tool, there was a substantial learning curve. Through a heuristic approach, addressing these discoveries with additional software and concepts resulted in a stronger set

Building a 3D geomechanical model of a gas field for geohazard prediction

NARCIS (Netherlands)

Orlic, B.; Eijs, R. van; Zijl, W.; Wees, J.D. van

2002-01-01

Land subsidence, triggered earthquakes and wellbore instabilities are some examples of geohazards caused by or related to the production of subsurface natural resources and storage of energy residues in the deep subsurface. The main objective of geomechanical modelling is to effectively predict

Geomechanics in hard rock mining-Lessons from two case histories

International Nuclear Information System (INIS)

Heuze, F.E.

1982-01-01

This paper summarizes the geomechanics programs conducted in two hard rock underground mining operations in the Western United States, between 1966 and 1981. The two projects were directed towards understanding the behavior of the rock masses, at the scale of the caverns. To this end, the emphasis was put on large scale field measurements, complemented by limited laboratory testing. The results of these observations were used to build realistic finite element models of the underground chambers. In the marble mine, at Crestmore, California, the models were applied to the structural optimization of the room-and-pillar pattern. In the granite mining, at Climax, Nevada Test Site, the models explained some unusual stress changes observed during excavation. Based on the large number of geomechanical techniques employed, specific conclusions and recommendations are offered regarding the quality, applicability, and usefulness of the various methods. The two case histories clearly indicate that numerical models are extremely useful for a detailed understanding of the structural behavior of mine openings. To be realistic, these models must be based first and foremost on large scale field observations. The lessons learned on these two projects also are directly applicable to the design and analysis of nuclear waste repositories in hard rocks such as basalt, granite, and welded tuff

An Artificially Intelligent Technique to Generate Synthetic Geomechanical Well Logs for the Bakken Formation

Directory of Open Access Journals (Sweden)

George Parapuram

2018-03-01

Full Text Available Artificially intelligent and predictive modelling of geomechanical properties is performed by creating supervised machine learning data models utilizing artificial neural networks (ANN and will predict geomechanical properties from basic and commonly used conventional well logs such as gamma ray, and bulk density. The predictive models were created by following the approach on a large volume of data acquired from 112 wells containing the Bakken Formation in North Dakota. The studied wells cover a large surface area of the formation containing the five main producing counties in North Dakota: Burke, Mountrail, McKenzie, Dunn, and Williams. Thus, with a large surface area being analyzed in this research, there is confidence with a high degree of certainty that an extensive representation of the Bakken Formation is modelled, by training neural networks to work on varying properties from the different counties containing the Bakken Formation in North Dakota. Shear wave velocity of 112 wells is also analyzed by regression methods and neural networks, and a new correlation is proposed for the Bakken Formation. The final goal of the research is to achieve supervised artificial neural network models that predict geomechanical properties of future wells with an accuracy of at least 90% for the Upper and Middle Bakken Formation. Thus, obtaining these logs by generating it from statistical and artificially intelligent methods shows a potential for significant improvements in performance, efficiency, and profitability for oil and gas operators.

Numerical Modeling of Geomechanical Processes Related to CO{sub 2} Injection within Generic Reservoirs

Energy Technology Data Exchange (ETDEWEB)

Eckert, Andreas

2013-05-31

In this project generic anticline structures have been used for numerical modeling analyses to study the influence of geometrical parameters, fluid flow boundary conditions, in situ stress regime and inter-bedding friction coefficient on geomechanical risks such as fracture reactivation and fracture generation. The resulting stress states for these structures are also used to determine safe drilling directions and a methodology for wellbore trajection optimization is developed that is applicable for non-Andersonian stress states. The results of the fluid flow simulation show that the type of fluid flow boundary condition is of utmost importance and has significant impact on all injection related parameters. It is recommended that further research is conducted to establish a method to quantify the fluid flow boundary conditions for injection applications. The results of the geomechanical simulation show that in situ stress regime is a crucial, if not the most important, factor determining geomechanical risks. For extension and strike slip stress regimes anticline structures should be favored over horizontally layered basin as they feature higher ΔP{sub c} magnitudes. If sedimentary basins are tectonically relaxed and their state of stress is characterized by the uni-axial strain model the basin is in exact frictional equilibrium and fluids should not be injected. The results also show that low inter bedding friction coefficients effectively decouple layers resulting in lower ΔP{sub c} magnitudes, especially for the compressional stress regime.

Modeling methods for systems study of geomechanical and mining technological objects

Energy Technology Data Exchange (ETDEWEB)

Glazov, D D

1983-01-01

Of the basic classes of problems solved during the accepted systems examination of the results of full scale, laboratory and analytical studies, the following are noted: the problems of detecting patterns in the limited empirical base and isolating new physical content in the phenomena which have not received effective explanation within the exhaustive use of the arsenal of traditional methods and techniques; problems for describing the subject field of complex natural systems through isolating their system models in the chaos of contradictory information as the bases for building automated systems for decision making; terminological questions; problems in determining the systems parameters and building structural models of new technologies which provide for dividing the physical effect by levels of geomechanical systems. Thus, at the present time studies of multilevel accepted models of organization of geomechanical systems are interpreted in new methods of structuring by an explosion of roofs difficult to collapse based on its screen creating and multiscreen grinding effect, introduced jointly by the DonUGI at the mines of the Donbass, and new methods for building technological systems for passage by complexes of geological disruptions introduced jointly with the IGD im. Skochinskiy in the Kuzbass and in the Mosbass.

Numerical investigation of CO2 storage in hydrocarbon field using a geomechanical-fluid coupling model

Directory of Open Access Journals (Sweden)

Guang Li

2016-09-01

Full Text Available Increasing pore pressure due to CO2 injection can lead to stress and strain changes of the reservoir. One of the safely standards for long term CO2 storage is whether stress and strain changes caused by CO2 injection will lead to irreversible mechanical damages of the reservoir and impact the integrity of caprock which could lead to CO2 leakage through previously sealing structures. Leakage from storage will compromise both the storage capacity and the perceived security of the project, therefore, a successful CO2 storage project requires large volumes of CO2 to be injected into storage site in a reliable and secure manner. Yougou hydrocarbon field located in Orods basin was chosen as storage site based on it's stable geological structure and low leakage risks. In this paper, we present a fluid pressure and stress-strain variations analysis for CO2 geological storage based on a geomechanical-fluid coupling model. Using nonlinear elasticity theory to describe the geomechanical part of the model, while using the Darcy's law to describe the fluid flow. Two parts are coupled together using the poroelasticity theory. The objectives of our work were: 1 evaluation of the geomechanical response of the reservoir to different CO2 injection scenarios. 2 assessment of the potential leakage risk of the reservoir caused by CO2 injection.

Geochemistry and ore prospecting

International Nuclear Information System (INIS)

Le Caignec, R.

1954-01-01

Applied geochemistry is a new technique which helps the geologist in detecting ore deposits. Some deposits, even when they are covered with rather thick surface structures, form around these zones where the infinitesimal content of some elements of soils or waters is notably different. These 'anomalies' may be contemporaneous to the deposit-structure (primary dispersion) or may have occurred later (secondary dispersion). Various factors rule these anomalies: ore-stability, soil homogeneity, water conditions, topography, vegetation, etc... Applied geochemistry is in fact the study of analysis techniques of metal traces in soils as well as the geological interpretation of observed anomalies. This report gives practical data on sampling methods, yields, costs and also on special problems of uranium geochemistry. (author) [fr

Radiogenic isotope geochemistry of sedimentary and aquatic systems

International Nuclear Information System (INIS)

Stille, P.; Shields, G.

1997-01-01

The following topics are discussed: Basic principles of isotopic geochemistry; weathering; isotopic geochemistry of river water; isotopic geochemistry in the environment; isotopic composition of seawater past and present (Sr, Nd, Pb, Os, Ce); isotope geochemistry of detrital and authigenic clay minerals in marine sediemnts (Rb-Sr, K-Ar, O); the Sm-N isotope system in detrital and authigenic argillaceous sediments. (SR), provided they are of exceptional interest and focused on a single topic. (orig./SR)

Radiogenic isotope geochemistry of sedimentary and aquatic systems

Energy Technology Data Exchange (ETDEWEB)

Stille, P.; Shields, G. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France). Centre de Sedimentologie et Geochimie de la Surface

1997-12-31

The following topics are discussed: Basic principles of isotopic geochemistry; weathering; isotopic geochemistry of river water; isotopic geochemistry in the environment; isotopic composition of seawater past and present (Sr, Nd, Pb, Os, Ce); isotope geochemistry of detrital and authigenic clay minerals in marine sediemnts (Rb-Sr, K-Ar, O); the Sm-N isotope system in detrital and authigenic argillaceous sediments. (SR), provided they are of exceptional interest and focused on a single topic. (orig./SR)

Preclosure monitoring and performance confirmation at Yucca Mountain: Applicability of geophysical, geohydrological, and geochemical methods

International Nuclear Information System (INIS)

Tsang, C.F.

1989-06-01

The present paper presents considerations on studies that would be required for preclosure monitoring and performance confirmation of a nuclear waste geologic repository in an unsaturated zone. The critical parameters that should be monitored are reviewed and two scales of measurement relevant to monitoring activities, room scale and repository scale, are taken as a framework for investigation. A number of monitoring methods based on geophysics, geohydrology, and geochemistry are briefly summarized for their potential usefulness for preclosure monitoring and performance confirmation of the geologic repository. Particular emphasis is given to measurement of the spatial distribution of parameters in contrast to single-point measurements of quantities. 12 refs., 1 fig., 1 tab

Investigation of intact rock geomechanical parameters' effects on commercial blocks' productivity within stone reserves: A case history of some quarries in Isfahan, Iran

Science.gov (United States)

Yarahmadi, Reza; Bagherpour, Raheb; Tabaei, Morteza; Sousa, Luis M. O.

2017-10-01

One of the common methods to determine commercial blocks productivity (CBP) in reserves of dimension stone is through the study of the discontinuities' network. However, this determination remains a difficult task due to geographical heterogeneity and lack of access to all reserves' formations. This study presents a new method based on various geomechanical tests performed on intact rocks that assessed the CBP of a dimension stones' rock mass. Assuming that a dimension stone's rock mass comprised a large block of an intact rock, due to tectonics, the geomechanical properties of this block had direct effects on the discontinuities created within it. Therefore, the geomechanical properties of the intact rock may be related to the CBP of a stone reserve. Based on this factor, this study explored the relationship among some geomechanical properties, including failure angle, uniaxial compressive strength, and modulus of elasticity, and CBP by using data acquired from 21 dimension stone quarries consisting of travertine, marble, and onyx groups. According to the results obtained from the analysis of the Isfahan province's Iranian quarries, failure angle was not highly related to the reserve's CBP. In marble quarries, CBP may decrease, if the compressive strength of an intact rock exceeds 60 MPa. Among the studied parameters, the saturated-to-dry ratio's modulus of elasticity had the greatest relationship to the CBP. Generally, the presented diagrams displayed that the correlation between geomechanical properties and the CBP were an appropriate guide in determining the potential cost-effectiveness of a accessing a particular rock reserve during the early exploration phase.

Use of the radon gas as a natural geophysical tracer; Utilizacion del gas radon como un trazador geofisico natural

Energy Technology Data Exchange (ETDEWEB)

Pena, P.; Balcazar, M.; Flores R, J.H.; Lopez M, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2006-07-01

In this work it is denoted the applications of the radon gas like a natural geophysical radiotracer in the different branches of the Earth Sciences (Geology, geophysics and geochemistry). It importance resides in its employment like one additional tool to register the possible occurrence of seismic events by means of radon anomalies that are presented in land movements (volcanic eruptions and presence of geothermal areas), as well as its potential in environmental works whose purpose is the evaluation of the feather of contamination in the underground water and the porous media for spills of hydrocarbons. The measurement techniques to determine the concentration of radon was carried out by means of Solid Detectors of Nuclear tracks, as well as by Liquid scintillation, Clipperton, Honeywell, AlphaGUARD. The towns where these techniques its were applied were: Mexico City, Estado de Mexico (Toluca, ININ), Jalisco (The Spring), Guerrero coast. (Author)

Geomechanics of the Spent Fuel Test: Climax

International Nuclear Information System (INIS)

Wilder, D.G.; Yow, J.L. Jr.

1987-07-01

Three years of geomechanical measurements were made at the Spent Fuel Test-Climax (SFT-C) 1400 feet underground in fractured granitic rock. Heating of the rock mass resulted from emplacement of spent fuel as well as the heating by electrical heaters. Cooldown of the rock occurred after the spent fuel was removed and the heaters were turned off. The measurements program examines both gross and localized responses of the rock mass to thermal loading, to evaluate the thermomechanical response of sheared and fractured rock with that of relatively unfractured rock, to compare the magnitudes of displacements during mining with those induced by extensive heating of the rock mass, and to check assumptions regarding symmetry and damaged zones made in numerical modeling of the SFT-C. 28 refs., 113 figs., 10 tabs

Earth Sciences Division annual report 1990

International Nuclear Information System (INIS)

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

Earth Sciences Division annual report 1990

Energy Technology Data Exchange (ETDEWEB)

NONE

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.

Deformation Monitoring of Geomechanical Model Test and Its Application in Overall Stability Analysis of a High Arch Dam

Directory of Open Access Journals (Sweden)

Baoquan Yang

2015-01-01

Full Text Available Geomechanical model testing is an important method for studying the overall stability of high arch dams. The main task of a geomechanical model test is deformation monitoring. Currently, many types of deformation instruments are used for deformation monitoring of dam models, which provide valuable information on the deformation characteristics of the prototype dams. However, further investigation is required for assessing the overall stability of high arch dams through analyzing deformation monitoring data. First, a relationship for assessing the stability of dams is established based on the comprehensive model test method. Second, a stability evaluation system is presented based on the deformation monitoring data, together with the relationships between the deformation and overloading coefficient. Finally, the comprehensive model test method is applied to study the overall stability of the Jinping-I high arch dam. A three-dimensional destructive test of the geomechanical model dam is conducted under reinforced foundation conditions. The deformation characteristics and failure mechanisms of the dam abutments and foundation were investigated. The test results indicate that the stability safety factors of the dam abutments and foundation range from 5.2 to 6.0. These research results provide an important scientific insight into the design, construction, and operation stages of this project.

Geomechanical characterization of volcanic rocks using empirical systems and data mining techniques

OpenAIRE

T. Miranda; L.R. Sousa; A.T. Gomes; J. Tinoco; C. Ferreira

2018-01-01

This paper tries to characterize volcanic rocks through the development and application of an empirical geomechanical system. Geotechnical information was collected from the samples from several Atlantic Ocean islands including Madeira, Azores and Canarias archipelagos. An empirical rock classification system termed as the volcanic rock system (VRS) is developed and presented in detail. Results using the VRS are compared with those obtained using the traditional rock mass rating (RMR) system....

Numerical investigation and Uncertainty Quantification of the Impact of the geological and geomechanical properties on the seismo-acoustic responses of underground chemical explosions

Science.gov (United States)

Ezzedine, S. M.; Pitarka, A.; Vorobiev, O.; Glenn, L.; Antoun, T.

2017-12-01

We have performed three-dimensional high resolution simulations of underground chemical explosions conducted recently in jointed rock outcrop as part of the Source Physics Experiments (SPE) being conducted at the Nevada National Security Site (NNSS). The main goal of the current study is to investigate the effects of the structural and geomechanical properties on the spall phenomena due to underground chemical explosions and its subsequent effect on the seismo-acoustic signature at far distances. Two parametric studies have been undertaken to assess the impact of different 1) conceptual geological models including a single layer and two layers model, with and without joints and with and without varying geomechanical properties, and 2) depth of bursts of the chemical explosions and explosion yields. Through these investigations we have explored not only the near-field response of the chemical explosions but also the far-field responses of the seismic and the acoustic signatures. The near-field simulations were conducted using the Eulerian and Lagrangian codes, GEODYN and GEODYN -L, respectively, while the far-field seismic simulations were conducted using the elastic wave propagation code, WPP, and the acoustic response using the Kirchhoff-Helmholtz-Rayleigh time-dependent approximation code, KHR. Though a series of simulations we have recorded the velocity field histories a) at the ground surface on an acoustic-source-patch for the acoustic simulations, and 2) on a seismic-source-box for the seismic simulations. We first analyzed the SPE3 experimental data and simulated results, then simulated SPE4-prime, SPE5, and SPE6 to anticipate their seismo-acoustic responses given conditions of uncertainties. SPE experiments were conducted in a granitic formation; we have extended the parametric study to include other geological settings such dolomite and alluvial formations. These parametric studies enabled us 1) investigating the geotechnical and geophysical key parameters

Role of geomechanically grown fractures on dispersive transport in heterogeneous geological formations

KAUST Repository

Nick, H. M.

2011-11-04

A second order in space accurate implicit scheme for time-dependent advection-dispersion equations and a discrete fracture propagation model are employed to model solute transport in porous media. We study the impact of the fractures on mass transport and dispersion. To model flow and transport, pressure and transport equations are integrated using a finite-element, node-centered finite-volume approach. Fracture geometries are incrementally developed from a random distributions of material flaws using an adoptive geomechanical finite-element model that also produces fracture aperture distributions. This quasistatic propagation assumes a linear elastic rock matrix, and crack propagation is governed by a subcritical crack growth failure criterion. Fracture propagation, intersection, and closure are handled geometrically. The flow and transport simulations are separately conducted for a range of fracture densities that are generated by the geomechanical finite-element model. These computations show that the most influential parameters for solute transport in fractured porous media are as follows: fracture density and fracture-matrix flux ratio that is influenced by matrix permeability. Using an equivalent fracture aperture size, computed on the basis of equivalent permeability of the system, we also obtain an acceptable prediction of the macrodispersion of poorly interconnected fracture networks. The results hold for fractures at relatively low density. © 2011 American Physical Society.

Role of geomechanically grown fractures on dispersive transport in heterogeneous geological formations

KAUST Repository

Nick, H. M.; Paluszny, A.; Blunt, M. J.; Matthai, S. K.

2011-01-01

A second order in space accurate implicit scheme for time-dependent advection-dispersion equations and a discrete fracture propagation model are employed to model solute transport in porous media. We study the impact of the fractures on mass transport and dispersion. To model flow and transport, pressure and transport equations are integrated using a finite-element, node-centered finite-volume approach. Fracture geometries are incrementally developed from a random distributions of material flaws using an adoptive geomechanical finite-element model that also produces fracture aperture distributions. This quasistatic propagation assumes a linear elastic rock matrix, and crack propagation is governed by a subcritical crack growth failure criterion. Fracture propagation, intersection, and closure are handled geometrically. The flow and transport simulations are separately conducted for a range of fracture densities that are generated by the geomechanical finite-element model. These computations show that the most influential parameters for solute transport in fractured porous media are as follows: fracture density and fracture-matrix flux ratio that is influenced by matrix permeability. Using an equivalent fracture aperture size, computed on the basis of equivalent permeability of the system, we also obtain an acceptable prediction of the macrodispersion of poorly interconnected fracture networks. The results hold for fractures at relatively low density. © 2011 American Physical Society.

Dynamic Fluid Flow and Geomechanical Coupling to Assess the CO2 Storage Integrity in Faulted Structures

Directory of Open Access Journals (Sweden)

Baroni A.

2015-04-01

Full Text Available The SiteChar research on the Southern Adriatic Sea site focused on the investigation of the geomechanical and hydrodynamic behaviour of the storage complex in the case of CO2 injection in a reservoir consisting of fractured carbonate formations. Special attention was paid to the effects that natural faults and fractures might have on CO2 migration, and the effects that injection might have on the stability of faults. This assessment was originally performed via a hydro-geomechanical one-way coupling which relies on an adequate representation of faults in the model, allowing one to simulate fluid flow along the fault plane and inside faults as well as evolution of the stress state due to CO2 injection. The geological model was populated with petrophysical and geomechanical parameters derived either from laboratory measurements performed on samples from a reservoir analogue, or published literature. Since only sparse data were available, various scenarios were simulated to take into account the uncertainties in the fluid flow and geomechanical properties of the model: the different state of faults (i.e., open or closed and various in situ stress state, commonly named geostatic stresses as the earth’s crust deformation is assumed to be slow regarding the short-term study. Various fluid flow parameters were also considered, although only one set of petrophysical data corresponding to the most realistic ones is considered here. Faults modeled as volumetric elements behave as flow pathways for fluids when they are conductive. The injected CO2 migrates inside and through the Rovesti fault, which is located near the injection well. The fluid flow also induces overpressure in the faults. The overpressure in the Rovesti fault reaches 2.2 MPa while it reaches 4.4 MPa at the bottom hole of the injector. Extending to about 30 km, the pore pressure field reaches the Gondola fault located at 15 km from the injection zone but the overpressure does not exceed

Geochemistry of silicon isotopes

Energy Technology Data Exchange (ETDEWEB)

Ding, Tiping; Li, Yanhe; Gao, Jianfei; Hu, Bin [Chinese Academy of Geological Science, Beijing (China). Inst. of Mineral Resources; Jiang, Shaoyong [China Univ. of Geosciences, Wuhan (China).

2018-04-01

Silicon is one of the most abundant elements in the Earth and silicon isotope geochemistry is important in identifying the silicon source for various geological bodies and in studying the behavior of silicon in different geological processes. This book starts with an introduction on the development of silicon isotope geochemistry. Various analytical methods are described and compared with each other in detail. The mechanisms of silicon isotope fractionation are discussed, and silicon isotope distributions in various extraterrestrial and terrestrial reservoirs are updated. Besides, the applications of silicon isotopes in several important fields are presented.

Geomechanical Simulation of Bayou Choctaw Strategic Petroleum Reserve - Model Calibration.

Energy Technology Data Exchange (ETDEWEB)

Park, Byoung [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-02-01

A finite element numerical analysis model has been constructed that consists of a realistic mesh capturing the geometries of Bayou Choctaw (BC) Strategic Petroleum Reserve (SPR) site and multi - mechanism deformation ( M - D ) salt constitutive model using the daily data of actual wellhead pressure and oil - brine interface. The salt creep rate is not uniform in the salt dome, and the creep test data for BC salt is limited. Therefore, the model calibration is necessary to simulate the geomechanical behavior of the salt dome. The cavern volumetric closures of SPR caverns calculated from CAVEMAN are used for the field baseline measurement. The structure factor, A 2 , and transient strain limit factor, K 0 , in the M - D constitutive model are used for the calibration. The A 2 value obtained experimentally from the BC salt and K 0 value of Waste Isolation Pilot Plant (WIPP) salt are used for the baseline values. T o adjust the magnitude of A 2 and K 0 , multiplication factors A2F and K0F are defined, respectively. The A2F and K0F values of the salt dome and salt drawdown skins surrounding each SPR cavern have been determined through a number of back fitting analyses. The cavern volumetric closures calculated from this model correspond to the predictions from CAVEMAN for six SPR caverns. Therefore, this model is able to predict past and future geomechanical behaviors of the salt dome, caverns, caprock , and interbed layers. The geological concerns issued in the BC site will be explained from this model in a follow - up report .

Urban environmental geochemistry of trace metals

International Nuclear Information System (INIS)

Wong, Coby S.C.; Li Xiangdong; Thornton, Iain

2006-01-01

As the world's urban population continues to grow, it becomes increasingly imperative to understand the dynamic interactions between human activities and the urban environment. The development of urban environmental geochemistry has yielded a significant volume of scientific information about geochemical phenomena found uniquely in the urban environment, such as the distribution, dispersion, and geochemical characteristics of some toxic and potentially toxic trace metals. The aim of this paper is to provide an overview of the development of urban environmental geochemistry as a field of scientific study and highlight major transitions during the course of its development from its establishment to the major scientific interests in the field today. An extensive literature review is also conducted of trace metal contamination of the urban terrestrial environment, in particular of urban soils, in which the uniqueness of the urban environment and its influences on trace metal contamination are elaborated. Potential areas of future development in urban environmental geochemistry are identified and discussed. - Urban environmental geochemistry as a scientific discipline provides valuable information on trace metal contamination of the urban environment and its associated health effects

Data inversion in coupled subsurface flow and geomechanics models

International Nuclear Information System (INIS)

Iglesias, Marco A; McLaughlin, Dennis

2012-01-01

We present an inverse modeling approach to estimate petrophysical and elastic properties of the subsurface. The aim is to use the fully coupled geomechanics-flow model of Girault et al (2011 Math. Models Methods Appl. Sci. 21 169–213) to jointly invert surface deformation and pressure data from wells. We use a functional-analytic framework to construct a forward operator (parameter-to-output map) that arises from the geomechanics-flow model of Girault et al. Then, we follow a deterministic approach to pose the inverse problem of finding parameter estimates from measurements of the output of the forward operator. We prove that this inverse problem is ill-posed in the sense of stability. The inverse problem is then regularized with the implementation of the Newton-conjugate gradient (CG) algorithm of Hanke (1997 Numer. Funct. Anal. Optim. 18 18–971). For a consistent application of the Newton-CG scheme, we establish the differentiability of the forward map and characterize the adjoint of its linearization. We provide assumptions under which the theory of Hanke ensures convergence and regularizing properties of the Newton-CG scheme. These properties are verified in our numerical experiments. In addition, our synthetic experiments display the capabilities of the proposed inverse approach to estimate parameters of the subsurface by means of data inversion. In particular, the added value of measurements of surface deformation in the estimation of absolute permeability is quantified with respect to the standard history matching approach of inverting production data with flow models. The proposed methodology can be potentially used to invert satellite geodetic data (e.g. InSAR and GPS) in combination with production data for optimal monitoring and characterization of the subsurface. (paper)

Geomechanical issues of anthropogenic CO2 sequestration in exploited gas fields

International Nuclear Information System (INIS)

Ferronato, Massimiliano; Gambolati, Giuseppe; Janna, Carlo; Teatini, Pietro

2010-01-01

Anthropogenic CO 2 sequestration in deep geological formations may represent a viable option to fulfil the requirements of the 1997 Kyoto protocol on the reduction of greenhouse gas emissions. Scenarios of CO 2 sequestration through three injection wells in an exploited gas field located in the Po sedimentary basin (Italy) are simulated with the final target to understand the geomechanical consequences of the injection of carbon dioxide. Investigated scenarios include, as a hypothetical case, the long-term injection of CO 2 until the initial reservoir pressure is exceeded by as much as 40% over a period of about 100 years. The process is analyzed from the geomechanical point of view using a finite element-interface element (FE-IE) model with the following main issues addressed: (1) prediction of the possible land vertical uplift and corresponding impact on the ground infrastructures; (2) evaluation of the stress state induced in the reservoir formation with the possible generation of fractures and (3) a risk analysis for the activation of existing faults. The geomechanical constitutive law of the Northern Adriatic basin relying on the radioactive marker interpretation is implemented into the FE model, while an elasto-plastic relationship based on the Mohr-Coulomb criterion is used for the IE reproducing the fault behaviour. The in situ stress prior to the gas field exploitation is compressive with the principal horizontal stress in the direction perpendicular to the major faults equal to the vertical stress. The results show that the ground surface rebound due to the overpressure generated by the CO 2 sequestration partially mitigates the land subsidence experienced by the area because of the previous gas field depletion with differential displacements that are confined within the safety bounds suggested in the literature for the surface infrastructures. Activation of a few faults lying close to the northern reservoir boundary points to a slip of a couple of

Geological Geophysical and structural studies in Mina Ratones (Pluton de Albala); Estudios geologico-estructurales y geofisicos en Mina Ratones (Pluton de Albala)

Energy Technology Data Exchange (ETDEWEB)

Perez-Estaun, A; Carbonell, R; Marti, D; Flecha, I [Instituto de Ciencias de la Tierra Jaume Almera. Barcelona (Spain); Escuder Viruete, J [Universidad complutense de Madrid. Madrid (Spain)

2002-07-01

Mina Ratones environmental restoration project included petrological, structural,geophysical, hydrogeological and hydrogeochemical studies. The main objective of the geologic-structural and geophysical studies was the Albala granite structural characterization around the Mina Ratones uranium mine. The location of facies, fault zones (faults and dykes) as well as the distribution of some physical properties inside the rock massif was obtained for a granitic black of 900, 500, and 500 m. The geologic-structural and geophysical techniques applied to Mina Ratones provided a multidisciplinary approach for high resolution characterization of rock massif, and the structures potentially containing fluids,able to be applied to the hydrogeological modelling to a particular area. Geological studies included a detailed structural mapping of the area surrounding the mine (1:5,000 scale), the geometric, kinematics, and dynamics analysis of fractures of all scales, the petrology and geochemistry of fault rocks and altered areas surrounding fractures, and the microstructural studies of samples from surface and core lags. The construction of geostatistical models in two and three dimensions had helped to characterize the Mina Ratones rock massif showing the spatial distribution of fault zones, fracture intensity, granite composition heterogeneities, fluid-rock interaction zones, and physical properties. (Author)

The geomechanical strength of carbonate rock in Kinta valley, Ipoh, Perak Malaysia

Science.gov (United States)

Mazlan, Nur Amanina; Lai, Goh Thian; Razib, Ainul Mardhiyah Mohd; Rafek, Abdul Ghani; Serasa, Ailie Sofyiana; Simon, Norbert; Surip, Noraini; Ern, Lee Khai; Mohamed, Tuan Rusli

2018-04-01

The stability of both cut rocks and underground openings were influenced by the geomechanical strength of rock materials, while the strength characteristics are influenced by both material characteristics and the condition of weathering. This paper present a systematic approach to quantify the rock material strength characteristics for material failure and material & discontinuities failure by using uniaxial compressive strength, point load strength index and Brazilian tensile strength for carbonate rocks. Statistical analysis of the results at 95 percent confidence level showed that the mean value of compressive strength, point load strength index and Brazilian tensile strength for with material failure and material & discontinuities failure were 76.8 ± 4.5 and 41.2 ± 4.1 MPa with standard deviation of 15.2 and 6.5 MPa, respectively. The point load strength index for material failure and material & discontinuities failure were 3.1 ± 0.2 MPa and 1.8 ± 0.3 MPa with standard deviation of 0.9 and 0.6 MPa, respectively. The Brazilian tensile strength with material failure and material & discontinuities failure were 7.1 ± 0.3 MPa and 4.1 ± 0.3 MPa with standard deviation of 1.4 and 0.6 MPa, respectively. The results of this research revealed that the geomechanical strengths of rock material of carbonate rocks for material & discontinuities failure deteriorates approximately ½ from material failure.

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

Science.gov (United States)

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

2005-12-01

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

Terrestrial Sequestration of CO2 – An Assessment of Research Needs

Energy Technology Data Exchange (ETDEWEB)

Dove, Patricia [Georgia Inst. of Technology, Atlanta, GA (United States); Richter, Frank [University of Chicago, Chicago, IL; Rudnicki, John W [Northwestern Univ., Evanston, IL (United States); Harris, Jerry [Stanford Univ., CA (United States); Logan, John M. [Logan and Associates, Inc., Bandon, Oregon; Warpinski, Norman R [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wawersik, Wolfgang R [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, John L [New Mexico Institute of Mining and Technology; Wong, Teng-Fong [State University of New York; Ortoleva, Peter J [Indiana University, Bloomington, Indiana; Orr, Jr., Franklin M [Stanford Univ., CA (United States); Pyrak-Nolte, Laura [Purdue Univ., West Lafayette, IN (United States)

1998-11-02

Scientific debate about global warming prompted the Office of Basic Energy Sciences (OBES) of the U.S. Department of Energy to assess a broad range of research possibilities that might result in more efficient energy and reduce the amount of greenhouse gases emitted to the atmosphere. Therefore, in May 1998, the Geosciences Research Program of OBES invited eleven panelists to a workshop in order to address the potential for the sequestration of CO2 in geologic formations as part of a possible OBES initiative on climate change technology. Starting with knowledge gained from the industrial use of CO2 for enhanced oil recovery, the panelists were asked to identify the fundamental scientific and technical issues that would enhance the safety, efficiency and predictability of terrestrial CO2 sequestration. This report is the product of the May, 1998 workshop and subsequent discussions among the panelists. Although many of the problems discussed cut across traditional geoscience disciplines, the background of the workshop participants naturally lead to a paper with four sections representing the perspectives of geohydrology, geochemistry, geomechanics, and geophysics.

DOE workshop: Sedimentary systems, aqueous and organic geochemistry

International Nuclear Information System (INIS)

1993-07-01

A DOE workshop on sedimentary systems, aqueous and organic geochemistry was held July 15-16, 1993 at Lawrence Berkeley Laboratory. Papers were organized into several sections: Fundamental Properties, containing papers on the thermodynamics of brines, minerals and aqueous electrolyte solutions; Geochemical Transport, covering 3-D imaging of drill core samples, hydrothermal geochemistry, chemical interactions in hydrocarbon reservoirs, fluid flow model application, among others; Rock-Water Interactions, with presentations on stable isotope systematics of fluid/rock interaction, fluid flow and petotectonic evolution, grain boundary transport, sulfur incorporation, tracers in geologic reservoirs, geothermal controls on oil-reservoir evolution, and mineral hydrolysis kinetics; Organic Geochemistry covered new methods for constraining time of hydrocarbon migration, kinetic models of petroleum formation, mudstones in burial diagenesis, compound-specific carbon isotope analysis of petroleums, stability of natural gas, sulfur in sedimentary organic matter, organic geochemistry of deep ocean sediments, direct speciation of metal by optical spectroscopies; and lastly, Sedimentary Systems, covering sequence stratigraphy, seismic reflectors and diagenetic changes in carbonates, geochemistry and origin of regional dolomites, and evidence of large comet or asteroid impacts at extinction boundaries

DOE workshop: Sedimentary systems, aqueous and organic geochemistry

Energy Technology Data Exchange (ETDEWEB)

1993-07-01

A DOE workshop on sedimentary systems, aqueous and organic geochemistry was held July 15-16, 1993 at Lawrence Berkeley Laboratory. Papers were organized into several sections: Fundamental Properties, containing papers on the thermodynamics of brines, minerals and aqueous electrolyte solutions; Geochemical Transport, covering 3-D imaging of drill core samples, hydrothermal geochemistry, chemical interactions in hydrocarbon reservoirs, fluid flow model application, among others; Rock-Water Interactions, with presentations on stable isotope systematics of fluid/rock interaction, fluid flow and petotectonic evolution, grain boundary transport, sulfur incorporation, tracers in geologic reservoirs, geothermal controls on oil-reservoir evolution, and mineral hydrolysis kinetics; Organic Geochemistry covered new methods for constraining time of hydrocarbon migration, kinetic models of petroleum formation, mudstones in burial diagenesis, compound-specific carbon isotope analysis of petroleums, stability of natural gas, sulfur in sedimentary organic matter, organic geochemistry of deep ocean sediments, direct speciation of metal by optical spectroscopies; and lastly, Sedimentary Systems, covering sequence stratigraphy, seismic reflectors and diagenetic changes in carbonates, geochemistry and origin of regional dolomites, and evidence of large comet or asteroid impacts at extinction boundaries.

Applicability of geomechanical classifications for estimation of strength properties in Brazilian rock masses.

Science.gov (United States)

Santos, Tatiana B; Lana, Milene S; Santos, Allan E M; Silveira, Larissa R C

2017-01-01

Many authors have been proposed several correlation equations between geomechanical classifications and strength parameters. However, these correlation equations have been based in rock masses with different characteristics when compared to Brazilian rock masses. This paper aims to study the applicability of the geomechanical classifications to obtain strength parameters of three Brazilian rock masses. Four classification systems have been used; the Rock Mass Rating (RMR), the Rock Mass Quality (Q), the Geological Strength Index (GSI) and the Rock Mass Index (RMi). A strong rock mass and two soft rock masses with different degrees of weathering located in the cities of Ouro Preto and Mariana, Brazil; were selected for the study. Correlation equations were used to estimate the strength properties of these rock masses. However, such correlations do not always provide compatible results with the rock mass behavior. For the calibration of the strength values obtained through the use of classification systems, ​​stability analyses of failures in these rock masses have been done. After calibration of these parameters, the applicability of the various correlation equations found in the literature have been discussed. According to the results presented in this paper, some of these equations are not suitable for the studied rock masses.

On the fixed-stress split scheme as smoother in multigrid methods for coupling flow and geomechanics

NARCIS (Netherlands)

F.J. Gaspar Lorenz (Franscisco); C. Rodrigo (Carmen)

2017-01-01

textabstractThe fixed-stress split method has been widely used as solution method in the coupling of flow and geomechanics. In this work, we analyze the behavior of an inexact version of this algorithm as smoother within a geometric multigrid method, in order to obtain an efficient monolithic solver

Geomechanical Response of Jointed Caprock During CO2 Geological Sequestration

Science.gov (United States)

Newell, P.; Martinez, M. J.; Bishop, J. E.

2014-12-01

Geological sequestration of CO2 refers to the injection of supercritical CO2 into deep reservoirs trapped beneath a low-permeability caprock formation. Maintaining caprock integrity during the injection process is the most important factor for a successful injection. In this work we evaluate the potential for jointed caprock during injection scenarios using coupled three-dimensional multiphase flow and geomechanics modeling. Evaluation of jointed/fractured caprock systems is of particular concern to CO2 sequestration because creation or reactivation of joints (mechanical damage) can lead to enhanced pathways for leakage. In this work, we use an equivalent continuum approach to account for the joints within the caprock. Joint's aperture and non-linear stiffness of the caprock will be updated dynamically based on the effective normal stress. Effective permeability field will be updated based on the joints' aperture creating an anisotropic permeability field throughout the caprock. This feature would add another coupling between the solid and fluid in addition to basic Terzaghi's effective stress concept. In this study, we evaluate the impact of the joint's orientation and geometry of caprock and reservoir layers on geomechanical response of the CO2 geological systems. This work is supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

High Temperature Versus Geomechanical Parameters of Selected Rocks – The Present State of Research

Directory of Open Access Journals (Sweden)

Anna Sygała

2013-01-01

Full Text Available This paper presents the current state of knowledge concerning the examination of the impact of increased temperatures on changes of geomechanical properties of rocks. Based on historical data, the shape of stress–strain characteristics that illustrate the process of the destruction of rock samples as a result of load impact under uniaxial compression in a testing machine, were discussed. The results from the studies on changes in the basic strength and elasticity parameters of rocks, such as the compressive strength and Young’s modulus were compared. On their basis, it was found that temperature has a significant effect on the change of geomechanical properties of rocks. The nature of these changes also depends on other factors (apart from temperature. They are, among others: the mineral composition of rock, the porosity and density. The research analysis showed that changes in the rock by heating it at various temperatures and then uniaxially loading it in a testing machine, are different for different rock types. Most of the important processes that cause changes in the values of the strength parameters of the examined rocks occured in the temperature range of 400 to 600 °C.

Geophysical Field Theory

International Nuclear Information System (INIS)

Eloranta, E.

2003-11-01

The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)

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

Science.gov (United States)

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

Fundamentals of Geophysics

Science.gov (United States)

Lowrie, William

1997-10-01

This unique textbook presents a comprehensive overview of the fundamental principles of geophysics. Unlike most geophysics textbooks, it combines both the applied and theoretical aspects to the subject. The author explains complex geophysical concepts using abundant diagrams, a simplified mathematical treatment, and easy-to-follow equations. After placing the Earth in the context of the solar system, he describes each major branch of geophysics: gravitation, seismology, dating, thermal and electrical properties, geomagnetism, paleomagnetism and geodynamics. Each chapter begins with a summary of the basic physical principles, and a brief account of each topic's historical evolution. The book will satisfy the needs of intermediate-level earth science students from a variety of backgrounds, while at the same time preparing geophysics majors for continued study at a higher level.

Conference summaries

International Nuclear Information System (INIS)

1986-01-01

This volume contains conference summaries of the international conference on radioactive waste management of the Canadian Nuclear Society. Topics of discussion include: storage and disposal; hydrogeology and geochemistry; transportation; buffers and backfill; public attitudes; tailings; site investigations and geomechanics; concrete; economics; licensing; matrix materials and container design; durability of fuel; biosphere modelling; radioactive waste processing; and, future options

Geophysical borehole logging

International Nuclear Information System (INIS)

McCann, D.; Barton, K.J.; Hearn, K.

1981-08-01

Most of the available literature on geophysical borehole logging refers to studies carried out in sedimentary rocks. It is only in recent years that any great interest has been shown in geophysical logging in boreholes in metamorphic and igneous rocks following the development of research programmes associated with geothermal energy and nuclear waste disposal. This report is concerned with the programme of geophysical logging carried out on the three deep boreholes at Altnabreac, Caithness, to examine the effectiveness of these methods in crystalline rock. Of particular importance is the assessment of the performance of the various geophysical sondes run in the boreholes in relation to the rock mass properties. The geophysical data can be used to provide additional in-situ information on the geological, hydrogeological and engineering properties of the rock mass. Fracturing and weathering in the rock mass have a considerable effect on both the design parameters for an engineering structure and the flow of water through the rock mass; hence, the relation between the geophysical properties and the degree of fracturing and weathering is examined in some detail. (author)

HMF-Geophysics - An Update

Science.gov (United States)

Crook, N.; Knight, R.; Robinson, D.

2007-12-01

There is growing recognition of the challenges we face, in many parts of the world, in finding and maintaining clean sources of water for human consumption and agricultural use, while balancing the needs of the natural world. Advancements in hydrologic sciences are needed in order to develop an improved understanding of the controls on the quantity, movement, and quality of water, thus enhancing our ability to better protect and manage our water resources. Geophysical methods can play a central role in these investigations. CUAHSI (Consortium of Universities for the Advancement of Hydrologic Sciences) is developing, with the support of the National Science Foundation, a Hydrologic Measurement Facility (HMF), which contains a Geophysics module, referred to as HMF-Geophysics. The Geophysics module will support and advance the use of geophysics for hydrologic applications. Currently in second year of a 3 year pilot study, the main aim of HMF-Geophysics is to develop the infrastructure necessary to provide geophysical techniques and the expertise to apply them correctly for the hydrological community. The current working model consists of a central HMF-Geophysics facility and a number of volunteer nodes. The latter consists of individuals at universities who have volunteered to be part of HMF-Geophysics by using their equipment, and/or software, and expertise, in research partnerships with hydrologists. In response to an inquiry the central facility takes on the evaluation of the potential of geophysics to the area of research/watershed. The central facility can then undertake a feasibility study to determine how/if geophysical methods could be of use, and to evaluate the "value-added" by geophysics to the science. Once it is clear that the geophysics can contribute in a significant way to addressing the science questions the central facility works with the hydrologist to set up the next step. Our assumption is that at this point, the hydrologist (perhaps with a

User's guide of TOUGH2-EGS-MP: A Massively Parallel Simulator with Coupled Geomechanics for Fluid and Heat Flow in Enhanced Geothermal Systems VERSION 1.0

Energy Technology Data Exchange (ETDEWEB)

Xiong, Yi [Colorado School of Mines, Golden, CO (United States); Fakcharoenphol, Perapon [Colorado School of Mines, Golden, CO (United States); Wang, Shihao [Colorado School of Mines, Golden, CO (United States); Winterfeld, Philip H. [Colorado School of Mines, Golden, CO (United States); Zhang, Keni [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Yu-Shu [Colorado School of Mines, Golden, CO (United States)

2013-12-01

TOUGH2-EGS-MP is a parallel numerical simulation program coupling geomechanics with fluid and heat flow in fractured and porous media, and is applicable for simulation of enhanced geothermal systems (EGS). TOUGH2-EGS-MP is based on the TOUGH2-MP code, the massively parallel version of TOUGH2. In TOUGH2-EGS-MP, the fully-coupled flow-geomechanics model is developed from linear elastic theory for thermo-poro-elastic systems and is formulated in terms of mean normal stress as well as pore pressure and temperature. Reservoir rock properties such as porosity and permeability depend on rock deformation, and the relationships between these two, obtained from poro-elasticity theories and empirical correlations, are incorporated into the simulation. This report provides the user with detailed information on the TOUGH2-EGS-MP mathematical model and instructions for using it for Thermal-Hydrological-Mechanical (THM) simulations. The mathematical model includes the fluid and heat flow equations, geomechanical equation, and discretization of those equations. In addition, the parallel aspects of the code, such as domain partitioning and communication between processors, are also included. Although TOUGH2-EGS-MP has the capability for simulating fluid and heat flows coupled with geomechanical effects, it is up to the user to select the specific coupling process, such as THM or only TH, in a simulation. There are several example problems illustrating applications of this program. These example problems are described in detail and their input data are presented. Their results demonstrate that this program can be used for field-scale geothermal reservoir simulation in porous and fractured media with fluid and heat flow coupled with geomechanical effects.

Characterising and modelling regolith stratigraphy using multiple geophysical techniques

Science.gov (United States)

Thomas, M.; Cremasco, D.; Fotheringham, T.; Hatch, M. A.; Triantifillis, J.; Wilford, J.

2013-12-01

-registration, depth correction, etc.) each geophysical profile was evaluated by matching the core data. Applying traditional geophysical techniques, the best profiles were inverted using the core data creating two-dimensional (2-D) stratigraphic regolith models for each transect, and evaluated using independent validation. Next, in a test of an alternative method borrowed from digital soil mapping, the best preprocessed geophysical profiles were co-registered and stratigraphic models for each property created using multivariate environmental correlation. After independent validation, the qualities of the latest models were compared to the traditionally derived 2-D inverted models. Finally, the best overall stratigraphic models were used in conjunction with local environmental data (e.g. geology, geochemistry, terrain, soils) to create conceptual regolith hillslope models for each transect highlighting important features and processes, e.g. morphology, hydropedology and weathering characteristics. Results are presented with recommendations regarding the use of geophysics in modelling regolith stratigraphy at fine scales.

Clay shale as host rock. A geomechanical contribution about Opalinus clay; Tonstein als Wirtsgestein. Ein geomechanischer Beitrag ueber Opalinuston

Energy Technology Data Exchange (ETDEWEB)

Lempp, Christof; Menezes, Flora; Sachwitz, Simon [Halle-Wittenberg Univ., Halle (Saale) (Germany). Inst. fuer Geowissenschaften und Geographie

2016-12-15

The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

Final Scientific/Technical Report for project “Geomechanical Monitoring for CO₂ Hub Storage: Production and Injection at Kevin Dome

Energy Technology Data Exchange (ETDEWEB)

Daley, Thomas M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Vasco, Don [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ajo-Franklin, Jonathan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dobeck, Laura [Montana State Univ., Bozeman, MT (United States); Spangler, Lee [Montana State Univ., Bozeman, MT (United States); Leonti, Michelle [Montana State Univ., Bozeman, MT (United States)

2017-06-27

After learning that the TDS value in the target injection formation at the Kevin Dome site is too low to qualify for an EPA Class VI CO2 injection permit, the BSCSP project was re-scoped such that injection of CO2 is no longer planned. With no injection planned, the Geomechanics project was closed. In this final report, we describe the objective and approach of the project as proposed, and the limited results obtained before stopping work. The objective of the proposed research was the development & validation of an integrated monitoring approach for quantifying the interactions between large-scale geological carbon storage (GCS) and subsurface geomechanical state, particularly perturbations relevant to reservoir integrity such as fault reactivation and induced fracturing. In the short period of work before knowing the fate of the Kevin Dome project, we (1) researched designs for both the proposed InSAR corner reflectors as well as the near-surface 3C seismic stations; (2) developed preliminary elastic geomechanical models; (3) developed a second generation deformation prediction for the BSCSP Kevin Dome injection site; and (4) completed a preliminary map of InSAR monuments and shallow MEQ wells in the vicinity of the BSCSP injection pad.

SHELL ISOTOPE GEOCHEMISTRY

African Journals Online (AJOL)

ABSTRACT: The land snail Limicolaria kambeul chudeaui Germain was collected ... Key words/phrases: Ethiopia, isotope geochemistry, Lake Tilo, Limicolaria .... 1984), (c) 6'80 values of precipitation at Addis Ababa, with i 1 S.D. bars for the .... (breakfast cereal), deionised water and cuttlefish bone, the carbon and oxygen.

Geophysical Investigation of Upper Mantle Anomalies of the Australian-Antarctic Ridge

Science.gov (United States)

Park, S. H.; Choi, H.; Kim, S. S.; Lin, J.

2017-12-01

Australian-Antarctic Ridge (AAR) is situated between the Pacific-Antarctic Ridge (PAR) and Southeast Indian Ridge (SEIR), extending eastward from the Australian-Antarctic Discordance (AAD). Much of the AAR has been remained uncharted until 2011 because of its remoteness and harsh weather conditions. Since 2011, four multidisciplinary expeditions initiated by the Korea Polar Research Institute (KOPRI) have surveyed the little-explored eastern ends of the AAR and investigated the tectonics, geochemistry, and hydrothermal activity of this intermediate spreading system. Recent isotope studies using the new basalt samples from the AAR have led to the new hypothesis of the Southern Ocean mantle domain (SOM), which may have originated from the super-plume activity associated with the Gondwana break-up. In this study, we characterize the geophysics of the Southern Ocean mantle using the newly acquired shipboard bathymetry and available geophysical datasets. First, we computed residual mantle Bouguer gravity anomalies (RMBA), gravity-derived crustal thickness, and residual topography along the AAR in order to obtain a geological proxy for regional variations in magma supply. The results of these analyses revealed that the southern flank of the AAR is associated with shallower seafloor, more negative RMBA, thicker crust, and/or less dense mantle in comparison to the conjugate northern flank. Furthermore, this north-south asymmetry becomes more prominent toward the central ridge segments of the AAR. Interestingly, the along-axis depths of the entire AAR are significantly shallower than the neighboring ridge systems and the global ridges of intermediate spreading rates. Such shallow depths are also correlated with regional negative geoid anomalies. Furthermore, recent mantle tomography models consistently showed that the upper mantle (< 250 km) below the AAR has low S-wave velocities, suggesting that it may be hotter than the nearby ridges. Such regional-scale anomalies of the

Uranium project. Geochemistry prospection[Study of Uranium geochemical prospection in Uruguay]; Proyecto Uranio. Prospeccion geoquimica

Energy Technology Data Exchange (ETDEWEB)

Lambert, J

1983-07-01

Geochemistry studies the distribution of the chemicals elements in the terrestrial crust and its ways to migrate. The terminology used in this report is the following one: 1) Principles of the prospection geochemistry 2) Stages of the prospection geochemistry 3)utility of the prospection geochemistry 4) geochemistry of uranium 5) procedures used within the framework of uranium project 6) Average available 7) Selection of the zones of prospection geochemistry 8) Stages of the prospection, Sample preparation and analisis 9) Presentation of the results.

Geophysics

CERN Document Server

Bolt, Bruce

1973-01-01

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

Advances in geophysics

CERN Document Server

Sato, Haruo

2013-01-01

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

Proceedings of the national symposium on current trends in geochemistry, exploration and environment: abstract book

International Nuclear Information System (INIS)

2015-01-01

The topics covered in this symposium are solid earth geochemistry and geochemical modeling, precambrian geology, geochemistry and petrogenesis, geochemistry, peterogenisis, sedimentology, chemostratigraphy and paleoclimate, atomic minerals, ferrous/non ferrous minerals, REE minerals, PGE and base metals, oil, hydrocarbons, industrial minerals and gem stones, hydrogeochemistry, environmental geochemistry, biogeochemistry and medical geology and analytical geochemistry and method development. Papers relevant to INIS are indexed separately

Joint seismic, hydrogeological, and geomechanical investigations of a fracture zone in the Grimsel Rock Laboratory, Switzerland

International Nuclear Information System (INIS)

Majer, E.L.; Myer, L.R.; Peterson, J.E. Jr.; Karasaki, K.; Long, J.C.S.; Martel, S.J.; Bluemling, P.; Vomvoris, S.

1990-06-01

This report is one of a series documenting the results of the Nagra-DOE Cooperative (NDC-I) research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a rock mass as a geologic repository for nuclear waste. From 1987 to 1989 the United States Department of Energy (DOE) and the Swiss Cooperative for the Storage of Nuclear Waste (Nagra) participated in an agreement to carryout experiments for understanding the effect of fractures in the storage and disposal of nuclear waste. As part of this joint work field and laboratory experiments were conducted at a controlled site in the Nagra underground Grimsel test site in Switzerland. The primary goal of these experiments in this fractured granite was to determine the fundamental nature of the propagation of seismic waves in fractured media, and to relate the seismological parameters to the hydrological parameters. The work is ultimately aimed at the characterization and monitoring of subsurface sites for the storage of nuclear waste. The seismic experiments utilizes high frequency (1000 to 10,000 Hertz) signals in a cross-hole configuration at scales of several tens of meters. Two-, three-, and four-sided tomographic images of the fractures and geologic structure were produced from over 60,000 raypaths through a 10 by 21 meter region bounded by two nearly horizontal boreholes and two tunnels. Intersecting this region was a dominant fracture zone which was the target of the investigations. In addition to these controlled seismic imaging experiments, laboratory work using core from this region were studied for the relation between fracture content, saturation, and seismic velocity and attenuation. In-situ geomechanical and hydrologic tests were carried out to determine the mechanical stiffness and conductivity of the fractures. 20 refs., 90 figs., 6 tabs

Marine geochemistry ocean circulation, carbon cycle and climate change

CERN Document Server

Roy-Barman, Matthieu

2016-01-01

Marine geochemistry uses chemical elements and their isotopes to study how the ocean works. It brings quantitative answers to questions such as: What is the deep ocean mixing rate? How much atmospheric CO2 is pumped by the ocean? How fast are pollutants removed from the ocean? How do ecosystems react to the anthropogenic pressure? The book provides a simple introduction to the concepts (environmental chemistry, isotopes), the methods (field approach, remote sensing, modeling) and the applications (ocean circulation, carbon cycle, climate change) of marine geochemistry with a particular emphasis on isotopic tracers. Marine geochemistry is not an isolated discipline: numerous openings on physical oceanography, marine biology, climatology, geology, pollutions and ecology are proposed and provide a global vision of the ocean. It includes new topics based on ongoing research programs such as GEOTRACES, Global Carbon Project, Tara Ocean. It provides a complete outline for a course in marine geochemistry. To favor a...

Indoor radon measurements in south west England explained by topsoil and stream sediment geochemistry, airborne gamma-ray spectroscopy and geology.

Science.gov (United States)

Ferreira, Antonio; Daraktchieva, Zornitza; Beamish, David; Kirkwood, Charles; Lister, T Robert; Cave, Mark; Wragg, Joanna; Lee, Kathryn

2018-01-01

Predictive mapping of indoor radon potential often requires the use of additional datasets. A range of geological, geochemical and geophysical data may be considered, either individually or in combination. The present work is an evaluation of how much of the indoor radon variation in south west England can be explained by four different datasets: a) the geology (G), b) the airborne gamma-ray spectroscopy (AGR), c) the geochemistry of topsoil (TSG) and d) the geochemistry of stream sediments (SSG). The study area was chosen since it provides a large (197,464) indoor radon dataset in association with the above information. Geology provides information on the distribution of the materials that may contribute to radon release while the latter three items provide more direct observations on the distributions of the radionuclide elements uranium (U), thorium (Th) and potassium (K). In addition, (c) and (d) provide multi-element assessments of geochemistry which are also included in this study. The effectiveness of datasets for predicting the existing indoor radon data is assessed through the level (the higher the better) of explained variation (% of variance or ANOVA) obtained from the tested models. A multiple linear regression using a compositional data (CODA) approach is carried out to obtain the required measure of determination for each analysis. Results show that, amongst the four tested datasets, the soil geochemistry (TSG, i.e. including all the available 41 elements, 10 major - Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Ti - plus 31 trace) provides the highest explained variation of indoor radon (about 40%); more than double the value provided by U alone (ca. 15%), or the sub composition U, Th, K (ca. 16%) from the same TSG data. The remaining three datasets provide values ranging from about 27% to 32.5%. The enhanced prediction of the AGR model relative to the U, Th, K in soils suggests that the AGR signal captures more than just the U, Th and K content in the soil. The

Geomechanical/Geochemical Modeling Studies Conducted within the International DECOVALEX Project

International Nuclear Information System (INIS)

Birkholzer, J.T.; Rutqvist, J.; Sonnenthal, E.L.; Barr, D.; Chijimatsu, M.; Kolditz, O.; Liu, Q.; Oda, Y.; Wang, W.; Xie, M.; Zhang, C.

2005-01-01

The DECOVALEX project is an international cooperative project initiated by SKI, the Swedish Nuclear Power Inspectorate, with participation of about 10 international organizations. The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled thermo-hydro-mechanical-chemical (THMC) processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. One of the research tasks, initiated in 2004 by the U.S. Department of Energy (DOE), addresses the long-term impact of geomechanical and geochemical processes on the flow conditions near waste emplacement tunnels. Within this task, four international research teams conduct predictive analysis of the coupled processes in two generic repositories, using multiple approaches and different computer codes. Below, we give an overview of the research task and report its current status

Geomechanical/Geochemical Modeling Studies Conducted Within the International DECOVALEX Project

International Nuclear Information System (INIS)

J.T. Birkholzer; J. Rutqvist; E.L. Sonnenthal; D. Barr; M.Chijimatsu; O. Kolditz; Q. Liu; Y. Oda; W. Wang; M. Xie; C. Zhang

2006-01-01

The DECOVALEX project is an international cooperative project initiated by SKI, the Swedish Nuclear Power Inspectorate, with participation of about 10 international organizations. The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled thermo-hydro-mechanical-chemical (THMC) processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. One of the research tasks, initiated in 2004 by the U.S. Department of Energy (DOE), addresses the long-term impact of geomechanical and geochemical processes on the flow conditions near waste emplacement tunnels. Within this task, four international research teams conduct predictive analysis of the coupled processes in two generic repositories, using multiple approaches and different computer codes. Below, we give an overview of the research task and report its current status

The effects of impure CO2 on reservoir sandstones: results from mineralogical and geomechanical experiments

Science.gov (United States)

Marbler, H.; Erickson, K. P.; Schmidt, M.; Lempp, Ch.; Pöllmann, H.

2012-04-01

An experimental study of the behaviour of reservoir sandstones from deep saline aquifers during the injection and geological storage of CO2 with the inherent impurities SOX and NOX is part of the German national project COORAL*. Sample materials were taken from outcrops of possible reservoir formations of Rotliegend and Bunter Sandstones from the North German Basin. A combination of mineralogical alteration experiments and geomechanical tests was carried out on these rocks to study the potential effects of the impurities within the CO2 pore fluid. Altered rock samples after the treatment with CO2 + SOX/NOX in an autoclave system were loaded in a triaxial cell under in-situ pressure and temperature conditions in order to estimate the modifications of the geomechanical rock properties. Mineralogical alterations were observed within the sandstones after the exposure to impure supercritical (sc)CO2 and brine, mainly of the carbonatic, but also of the silicatic cements, as well as of single minerals. Besides the partial solution effects also secondary carbonate and minor silicate mineral precipitates were observed within the pore space of the treated sandstones. These alterations affect the grain structure of the reservoir rock. Results of geomechanical experiments with unaltered sandstones show that the rock strength is influenced by the degree of rock saturation before the experiment and the chemical composition of the pore fluid (scCO2 + SOX + NOX). After long-term autoclave treatment with impure scCO2, the sandstone samples exhibit modified strength parameters and elastic deformation behaviour as well as changes in porosity compared to untreated samples. Furthermore, the injected fluid volume into the pore space of sandstones from the same lithotype varies during triaxial loading depending on the chemistry of the pore fluid. CO2 with NOX and SOX bearing fluid fills a significantly larger proportion of the sandstone pore space than brine with pure scCO2. * The

NRC nuclear waste geochemistry 1983

International Nuclear Information System (INIS)

Alexander, D.H.; Birchard, G.F.

1984-05-01

The purpose of the meeting was to present results from NRC-sponsored research and to identify regulatory research issues which need to be addressed prior to licensing a high-level waste repository. Important summaries of technical issues and recommendations are included with each paper. The issue reflect areas of technical uncertainty addressed by the NRC Research program in geochemistry. The objectives of the NRC Research Program in geochemistry are to provide a technical basis for waste management rulemaking, to provide the NRC Waste Management Licensing Office with information that can be used to support sound licensing decisions, and to identify investigations that need to be conducted by DOE to support a license application. Individual papers were processed for inclusion in the Energy Data Base

Geo-Mechanical Characterization of Carbonate Rock Masses by Means of Laser Scanner Technique

Science.gov (United States)

Palma, Biagio; Parise, Mario; Ruocco, Anna

2017-12-01

Knowledge of the geometrical and structural setting of rock masses is crucial to evaluate the stability and to design the most suitable stabilization works. In this work we use the Terrestrial Laser Scanning (TLS) at the site of the Grave of the Castellana Caves, a famous show cave in southern Italy. The Grave is the natural access to the cave system, produced by collapse of the vault, due to upward progression of instabilities in the carbonate rock masses. It is about 55-m high, bell-shaped, with maximum width of 120 m. Aim of the work is the characterization of carbonate rock masses from the structural and geo-mechanical standpoints through the use of innovative survey techniques. TLS survey provides a product consisting of millions of geo-referenced points, to be managed in space, to become a suitable database for the morphological and geological-structural analysis. Studying by means of TLS a rock face, partly inaccessible or located in very complex environments, allows to investigate slopes in their overall areal extent, thus offering advantages both as regards safety of the workers and time needed for the survey. In addition to TLS, the traditional approach was also followed by performing scanlines surveys along the rims of the Grave, following the ISRM recommendations for characterization of discontinuity in rock masses. A quantitative comparison among the data obtained by TLS technique and those deriving from the classical geo-mechanical survey is eventually presented, to discuss potentiality of drawbacks of the different techniques used for surveying the rock masses.

A Model to Couple Flow, Thermal and Reactive Chemical Transport, and Geo-mechanics in Variably Saturated Media

Science.gov (United States)

Yeh, G. T.; Tsai, C. H.

2015-12-01

This paper presents the development of a THMC (thermal-hydrology-mechanics-chemistry) process model in variably saturated media. The governing equations for variably saturated flow and reactive chemical transport are obtained based on the mass conservation principle of species transport supplemented with Darcy's law, constraint of species concentration, equation of states, and constitutive law of K-S-P (Conductivity-Degree of Saturation-Capillary Pressure). The thermal transport equation is obtained based on the conservation of energy. The geo-mechanic displacement is obtained based on the assumption of equilibrium. Conventionally, these equations have been implicitly coupled via the calculations of secondary variables based on primary variables. The mechanisms of coupling have not been obvious. In this paper, governing equations are explicitly coupled for all primary variables. The coupling is accomplished via the storage coefficients, transporting velocities, and conduction-dispersion-diffusion coefficient tensor; one set each for every primary variable. With this new system of equations, the coupling mechanisms become clear. Physical interpretations of every term in the coupled equations will be discussed. Examples will be employed to demonstrate the intuition and superiority of these explicit coupling approaches. Keywords: Variably Saturated Flow, Thermal Transport, Geo-mechanics, Reactive Transport.

Geomechanical Considerations for the Deep Borehole Field Test

Science.gov (United States)

Park, B. Y.

2015-12-01

Deep borehole disposal of high-level radioactive waste is under consideration as a potential alternative to shallower mined repositories. The disposal concept consists of drilling a borehole into crystalline basement rocks to a depth of 5 km, emplacement of canisters containing solid waste in the lower 2 km, and plugging and sealing the upper 3 km of the borehole. Crystalline rocks such as granites are particularly attractive for borehole emplacement because of their low permeability and porosity at depth, and high mechanical strength to resist borehole deformation. In addition, high overburden pressures contribute to sealing of some of the fractures that provide transport pathways. We present geomechanical considerations during construction (e.g., borehole breakouts, disturbed rock zone development, and creep closure), relevant to both the smaller-diameter characterization borehole (8.5") and the larger-diameter field test borehole (17"). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Organic geochemistry of fossil resins from the Czech Republic

Czech Academy of Sciences Publication Activity Database

Havelcová, Martina; Sýkorová, Ivana; Mach, K.; Dvořák, Z.

2014-01-01

Roč. 10, August (2014), s. 303-312 ISSN 1878-5220. [Geochemistry of the Earth's Surface (GES) Meeting /10./. Paris, 18.08.2014-23.08.2014] R&D Projects: GA ČR(CZ) GA13-18482S Institutional support: RVO:67985891 Keywords : fossil resin * amber * resinite * TMAH-Py-GC/MS Subject RIV: DD - Geochemistry

Geochemistry of sediments of the eastern continental shelf of India

Digital Repository Service at National Institute of Oceanography (India)

Mascarenhas, A.; Paropkari, A.L.; Murty, P.S.N.

The bulk and partition geochemistry of Al, Fe, Ti, Mn, Zn, and Cu have been investigated in sediments of the eastern continental shelf of India. The results show that (1) the bulk geochemistry varies from one shelf unit to the other, (2) all...

Physics of the earth crust

International Nuclear Information System (INIS)

Lauterbach, R.

1977-01-01

This book deals in 12 chapters, amongst other things, with the subjects: Structure of the crust and the upper earth mantle, geology and geophysics of sea beds, satellite and aero-methods of geophysics, state of the art of geothermal research, geophysical potential fields and their anomalies, applied seismology, electrical methods of geophysics, geophysics in engineering and rock engineering, borehole geophysics, petrophysics, and geochemistry. (RW) [de

A multimethod Global Sensitivity Analysis to aid the calibration of geomechanical models via time-lapse seismic data

Science.gov (United States)

Price, D. C.; Angus, D. A.; Garcia, A.; Fisher, Q. J.; Parsons, S.; Kato, J.

2018-03-01

Time-lapse seismic attributes are used extensively in the history matching of production simulator models. However, although proven to contain information regarding production induced stress change, it is typically only loosely (i.e. qualitatively) used to calibrate geomechanical models. In this study we conduct a multimethod Global Sensitivity Analysis (GSA) to assess the feasibility and aid the quantitative calibration of geomechanical models via near-offset time-lapse seismic data. Specifically, the calibration of mechanical properties of the overburden. Via the GSA, we analyse the near-offset overburden seismic traveltimes from over 4000 perturbations of a Finite Element (FE) geomechanical model of a typical High Pressure High Temperature (HPHT) reservoir in the North Sea. We find that, out of an initially large set of material properties, the near-offset overburden traveltimes are primarily affected by Young's modulus and the effective stress (i.e. Biot) coefficient. The unexpected significance of the Biot coefficient highlights the importance of modelling fluid flow and pore pressure outside of the reservoir. The FE model is complex and highly nonlinear. Multiple combinations of model parameters can yield equally possible model realizations. Consequently, numerical calibration via a large number of random model perturbations is unfeasible. However, the significant differences in traveltime results suggest that more sophisticated calibration methods could potentially be feasible for finding numerous suitable solutions. The results of the time-varying GSA demonstrate how acquiring multiple vintages of time-lapse seismic data can be advantageous. However, they also suggest that significant overburden near-offset seismic time-shifts, useful for model calibration, may take up to 3 yrs after the start of production to manifest. Due to the nonlinearity of the model behaviour, similar uncertainty in the reservoir mechanical properties appears to influence overburden

Modeling of coupled thermodynamic and geomechanical performance of underground compressed air energy storage in lined rock caverns

Energy Technology Data Exchange (ETDEWEB)

Rutqvist, Jonny; Kim, Hyung-Mok; Ryu, Dong-Woo; Synn, Joong-Ho; Song, Won-Kyong

2012-06-01

We applied coupled nonisothermal, multiphase fluid flow and geomechanical numerical modeling to study the coupled thermodynamic and geomechanical performance of underground compressed air energy storage (CAES) in concrete-lined rock caverns. The paper focuses on CAES in lined caverns at relatively shallow depth (e.g., 100 m depth) in which a typical CAES operational pressure of 5 to 8 MPa is significantly higher than both ambient fluid pressure and in situ stress. We simulated a storage operation that included cyclic compression and decompression of air in the cavern, and investigated how pressure, temperature and stress evolve over several months of operation. We analyzed two different lining options, both with a 50 cm thick low permeability concrete lining, but in one case with an internal synthetic seal such as steel or rubber. For our simulated CAES system, the thermodynamic analysis showed that 96.7% of the energy injected during compression could be recovered during subsequent decompression, while 3.3% of the energy was lost by heat conduction to the surrounding media. Our geomechanical analysis showed that tensile effective stresses as high as 8 MPa could develop in the lining as a result of the air pressure exerted on the inner surface of the lining, whereas thermal stresses were relatively smaller and compressive. With the option of an internal synthetic seal, the maximum effective tensile stress was reduced from 8 to 5 MPa, but was still in substantial tension. We performed one simulation in which the tensile tangential stresses resulted in radial cracks and air leakage though the lining. This air leakage, however, was minor (about 0.16% of the air mass loss from one daily compression) in terms of CAES operational efficiency, and did not significantly impact the overall energy balance of the system. However, despite being minor in terms of energy balance, the air leakage resulted in a distinct pressure increase in the surrounding rock that could be

The geomechanical characterization of the rocky mass foundation of the Tijuco Alto hydroelectric power plant, Ribeira River, Sao Paulo/Parana States, Brazil; Caracterizacao geomecanica do Macico de Fundacao da UHE Tijuco Alto (Rio Ribeira - SP/PR)

Energy Technology Data Exchange (ETDEWEB)

Figueiredo, Amarilis Lucia Casteli de

1996-07-01

This work has as its main objective the geomechanical characterization on the future rocky mass foundation of the Tijuco Alto dam, sited at the Ribeira river, in the cities of Ribeirao, Sao Paulo state and Adrianopolis, Parana state, Brazil, owned by the Companhia Brasileira de Aluminio (Brazilian company of Aluminium). To reach that target, field studies were made to qualify the geotechnical parameters of the rocky mass, in the axis area open galleries. It was also used in situ deformability and stress test results performed in those galleries, that were reinterpreted for a better adaptation of the mass values. The knowledge of the mass inherent characteristics together with the laboratories test results, allowed for the geomechanical classification applications in several different gallery sectors. The geomechanical data obtained allowed through mathematical expressions, to reach the rocky mass values correlations of interest to the work (deformability and strength), that could be compared to the in situ test results. That analysis permitted, besides the classification critical system evaluation, the geomechanical characterization of the rocky mass, focusing its ability to the dam arch construction. (author)

Application of Reservoir Flow Simulation Integrated with Geomechanics in Unconventional Tight Play

Science.gov (United States)

Lin, Menglu; Chen, Shengnan; Mbia, Ernest; Chen, Zhangxing

2018-01-01

Multistage hydraulic fracturing techniques, combined with horizontal drilling, have enabled commercial production from the vast reserves of unconventional tight formations. During hydraulic fracturing, fracturing fluid and proppants are pumped into the reservoir matrix to create the hydraulic fractures. Understanding the propagation mechanism of hydraulic fractures is essential to estimate their properties, such as half-length. In addition, natural fractures are often present in tight formations, which might be activated during the fracturing process and contribute to the post-stimulation well production rates. In this study, reservoir simulation is integrated with rock geomechanics to predict the well post-stimulation productivities. Firstly, a reservoir geological model is built based on the field data collected from the Montney formation in the Western Canadian Sedimentary Basin. The hydraulic fracturing process is then simulated through an integrated approach of fracturing fluid injection, rock geomechanics, and tensile failure criteria. In such a process, the reservoir pore pressure increases with a continuous injection of the fracturing fluid and proppants, decreasing the effective stress exerted on the rock matrix accordingly as the overburden pressure remains constant. Once the effective stress drops to a threshold value, tensile failure of the reservoir rock occurs, creating hydraulic fractures in the formation. The early production history of the stimulated well is history-matched to validate the predicted fracture geometries (e.g., half-length) generated from the fracturing simulation process. The effects of the natural fracture properties and well bottom-hole pressures on well productivity are also studied. It has been found that nearly 40% of hydraulic fractures propagate in the beginning stage (the pad step) of the fracturing schedule. In addition, well post-stimulation productivity will increase significantly if the natural fractures are propped or

Global water cycle: geochemistry and environment

National Research Council Canada - National Science Library

Berner, Elizabeth Kay; Berner, Robert A

1987-01-01

.... The book provides an integrated approach to global geochemistry and environmental problems and introduces the reader to some fundamental concepts of geology, oceanography, meteorology, environmental...

Sustainable urban development and geophysics

Science.gov (United States)

Liu, Lanbo; Chan, L. S.

2007-09-01

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

Comparative assessment of five potential sites for hydrothermal magma systems: geochemistry

Energy Technology Data Exchange (ETDEWEB)

White, A.F.

1980-08-01

A brief discussion is given of the geochemical objectives and questions that must be addressed in such an evaluation. A summary of the currently published literature that is pertinent in answering these questions is presented for each of the five areas: The Geysers-Clear Lake region, Long Valley, Rio Grand Rift, Roosevelt Hot Springs, and the Salton Trough. The major geochemical processes associated with proposed hydrothermal sites are categorized into three groups for presentation: geochemistry of magma and associated volcanic rocks, geochemistry of hydrothermal solutions, and geochemistry of hydrothermal alteration. (MHR)

Automation of the Design of the Anchorage System Taking into Account the Geomechanical State of the Massif and Mining Development Schemes

Directory of Open Access Journals (Sweden)

Demin Vladimir

2018-01-01

Full Text Available The article presents the system for the automation of the design of the anchorage, which regulates the calculation of the required parameters of the fasteners for the fastening of the fastening system. The main factors affecting the operation of the anchor support are grouped in the following way: mining and geological conditions, technical characteristics of the anchor support, geomechanical conditions for conducting and operating the mine workings. Mining and geological conditions for carrying out excavations include: physical and mechanical properties of rocks, the category of roof stability, fracturing, etc. Technical characteristics of the anchor support: material of the rod, filler, filling completeness, etc. Conditions (geomechanical of carrying out and exploitation of the mine workings: the depth of the conduct, the location relative to the zone of influence of the cleaning works, the location relative to the waste zone, etc. As a result of calculations the program gives out the basic parameters of the anchor support, which coincide with the parameters adopted by the passport.

The 8th ICGG International Conference on Gas Geochemistry Preface: Fluids and tectonics

Directory of Open Access Journals (Sweden)

F. Italiano

2007-06-01

Full Text Available The 8th International Conference on Gas Geochemistry provided the opportunity for scientists from different countries to meet each other, exchange ideas on the state of the art in gas geochemistry, and discuss advance in fluid geochemistry. The 8th ICGG meeting focused on three main geologic environments currently interacting with the human life: volcanoes, earthquakes and hydrocarbons. Ninety-four presentations gave participants chance to cover a variety of important research topics on gas geochemistry in geosciences including: gas migration in terrestrial and marine environments, Earth degassing and its relation to seismicity, volcanic eruptions, rare gases and application of isotope techniques, measurement and analytical techniques.

Proceedings of the Canadian Nuclear Society 2. international conference on radioactive waste management

International Nuclear Information System (INIS)

1986-01-01

These proceedings contain 136 papers on waste management from 19 countries. An index of the delegates and their affiliations is included. Emphasis was laid on the Canadian program for geologic disposal in hard rock. Sessions dealt with the following: storage and disposal, hydrogeology and geochemistry, transportation, buffers and backfill, public attitudes, tailings, site investigations and geomechanics, concrete, economics, licensing, matrix materials and container design, durability of fuel, biosphere modelling, radioactive waste processing, and future options

ANNALS OF GEOPHYSICS: AD MAJORA

Directory of Open Access Journals (Sweden)

Fabio Florindo

2014-03-01

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

Geomechanical applications for the Waste Isolation Pilot Plant (WIPP) project

International Nuclear Information System (INIS)

Matalucci, R.V.; Hunter, T.O.

1981-01-01

The Waste Isolation Pilot Plant (WIPP) is a research and development facility in bedded salt addressing the technical issues associated with the demonstration of disposal of radioactive waste from the defense programs of the USA. The geomechanical program includes laboratory experimentation, constitutive model and computer code development, and in-situ experimentation. Various material models, including creep for salt, and techniques for predicting room response under thermal and mechanical loads have been developed and are being applied to experiment and facility designs. A Benchmark II study has been conducted to compare the capabilities of nine structural codes to predict response of underground configuration under ambient temperature and with a thermal load of 7.5 W/m 2 . Parametric studies are being conducted to evaluate optimum room configurations. A series of in situ experiments is the next step towards validating models and predictive techniques. These experiments will be conducted in a facility in southeastern New Mexico mined at a depth of 659 m

Estimation of Sand Production Rate Using Geomechanical and Hydromechanical Models

Directory of Open Access Journals (Sweden)

Son Tung Pham

2017-01-01

Full Text Available This paper aims to develop a numerical model that can be used in sand control during production phase of an oil and gas well. The model is able to predict not only the onset of sand production using critical bottom hole pressure inferred from geomechanical modelling, but also the mass of sand produced versus time as well as the change of porosity versus space and time using hydromechanical modelling. A detailed workflow of the modelling was presented with each step of calculations. The empirical parameters were calibrated using laboratory data. Then the modelling was applied in a case study of an oilfield in Cuu Long basin. In addition, a sensitivity study of the effect of drawdown pressure was presented in this paper. Moreover, a comparison between results of different hydromechanical models was also addressed. The outcome of this paper demonstrated the possibility of modelling the sand production mass in real cases, opening a new approach in sand control in petroleum industry.

3D Printing and Digital Rock Physics for the Geosciences

Science.gov (United States)

Martinez, M. J.; Yoon, H.; Dewers, T. A.

2014-12-01

Imaging techniques for the analysis of porous structures have revolutionized our ability to quantitatively characterize geomaterials. For example, digital representations of rock from CT images and physics modeling based on these pore structures provide the opportunity to further advance our quantitative understanding of fluid flow, geomechanics, and geochemistry, and the emergence of coupled behaviors. Additive manufacturing, commonly known as 3D printing, has revolutionized production of custom parts, to the point where parts might be cheaper to print than to make by traditional means in a plant and ship. Some key benefits of additive manufacturing include short lead times, complex shapes, parts on demand, zero required inventory and less material waste. Even subtractive processing, such as milling and etching, may be economized by additive manufacturing. For the geosciences, recent advances in 3D printing technology may be co-opted to print reproducible porous structures derived from CT-imaging of actual rocks for experimental testing. The use of 3D printed microstructure allows us to surmount typical problems associated with sample-to-sample heterogeneity that plague rock physics testing and to test material response independent from pore-structure variability. Together, imaging, digital rocks and 3D printing potentially enables a new workflow for understanding coupled geophysical processes in a real, but well-defined setting circumventing typical issues associated with reproducibility, enabling full characterization and thus connection of physical phenomena to structure. In this talk we will discuss the possibilities that the marriage of these technologies can bring to geosciences, including examples from our current research initiatives in developing constitutive laws for transport and geomechanics via digital rock physics. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of

Developments in geophysical exploration methods

CERN Document Server

1982-01-01

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

Three-dimensional geophysical mapping of shallow water saturated altered rocks at Mount Baker, Washington: Implications for slope stability

Science.gov (United States)

Finn, Carol A.; Deszcz-Pan, Maryla; Ball, Jessica L.; Bloss, Benjamin J.; Minsley, Burke J.

2018-05-01

Water-saturated hydrothermal alteration reduces the strength of volcanic edifices, increasing the potential for catastrophic sector collapses that can lead to far traveled and destructive debris flows. Intense hydrothermal alteration significantly lowers the resistivity and magnetization of volcanic rock and therefore hydrothermally altered rocks can be identified with helicopter electromagnetic and magnetic measurements. Geophysical models constrained by rock properties and geologic mapping show that intensely altered rock is restricted to two small (500 m diameter), >150 m thick regions around Sherman Crater and Dorr Fumarole Field at Mount Baker, Washington. This distribution of alteration contrasts with much thicker and widespread alteration encompassing the summits of Mounts Adams and Rainier prior to the 5600 year old Osceola collapse, which is most likely due to extreme erosion and the limited duration of summit magmatism at Mount Baker. In addition, the models suggest that the upper 300 m of rock contains water which could help to lubricate potential debris flows. Slope stability modeling incorporating the geophysically modeled distribution of alteration and water indicates that the most likely and largest ( 0.1 km3) collapses are from the east side of Sherman Crater. Alteration at Dorr Fumarole Field raises the collapse hazard there, but not significantly because of its lower slope angles. Geochemistry and analogs from other volcanoes suggest a model for the edifice hydrothermal system.

Three-dimensional geophysical mapping of shallow water saturated altered rocks at Mount Baker, Washington: Implications for slope stability

Science.gov (United States)

Finn, Carol A.; Deszcz-Pan, Maria; Ball, Jessica L.; Bloss, Benjamin J.; Minsley, Burke J.

2018-01-01

Water-saturated hydrothermal alteration reduces the strength of volcanic edifices, increasing the potential for catastrophic sector collapses that can lead to far traveled and destructive debris flows. Intense hydrothermal alteration significantly lowers the resistivity and magnetization of volcanic rock and therefore hydrothermally altered rocks can be identified with helicopter electromagnetic and magnetic measurements. Geophysical models constrained by rock properties and geologic mapping show that intensely altered rock is restricted to two small (500 m diameter), >150 m thick regions around Sherman Crater and Dorr Fumarole Field at Mount Baker, Washington. This distribution of alteration contrasts with much thicker and widespread alteration encompassing the summits of Mounts Adams and Rainier prior to the 5600 year old Osceola collapse, which is most likely due to extreme erosion and the limited duration of summit magmatism at Mount Baker. In addition, the models suggest that the upper ~300 m of rock contains water which could help to lubricate potential debris flows. Slope stability modeling incorporating the geophysically modeled distribution of alteration and water indicates that the most likely and largest (~0.1 km3) collapses are from the east side of Sherman Crater. Alteration at Dorr Fumarole Field raises the collapse hazard there, but not significantly because of its lower slope angles. Geochemistry and analogs from other volcanoes suggest a model for the edifice hydrothermal system.

Chaos theory in geophysics: past, present and future

International Nuclear Information System (INIS)

Sivakumar, B.

2004-01-01

The past two decades of research on chaos theory in geophysics has brought about a significant shift in the way we view geophysical phenomena. Research on chaos theory in geophysics continues to grow at a much faster pace, with applications to a wide variety of geophysical phenomena and geophysical problems. In spite of our success in understanding geophysical phenomena also from a different (i.e. chaotic) perspective, there still seems to be lingering suspicions on the scope of chaos theory in geophysics. The goal of this paper is to present a comprehensive account of the achievements and status of chaos theory in geophysics, and to disseminate the hope and scope for the future. A systematic review of chaos theory in geophysics, covering a wide spectrum of geophysical phenomena studied (e.g. rainfall, river flow, sediment transport, temperature, pressure, tree ring series, etc.), is presented to narrate our past achievements not only in understanding and predicting geophysical phenomena but also in improving the chaos identification and prediction techniques. The present state of chaos research in geophysics (in terms of geophysical phenomena, problems, and chaos methods) and potential for future improvements (in terms of where, why and possibly how) are also highlighted. Our popular views of nature (i.e. stochastic and deterministic), and of geophysical phenomena in particular, are discussed, and the usefulness of chaos theory as a bridge between such views is also put forth

Geomechanical Assessments of Simultaneous Operation in the Case of Transition from Open Pit to Underground Mine in Vietnam

Science.gov (United States)

Niedbalski, Zbigniew; Nguyen, Phu Minh Vuong; Widzyk-Capehart, Eleonora

2018-03-01

Nowadays, for a number of reasons, many open pit mines are considering a transition from Open Pit (OP) to Underground (UG) to remain competitive. In OP-UG transition, UG operation is operated simultaneously with the OP operation for a certain period of time. Guidelines for the simultaneous operation of OP and UG are very difficult to establish, as there are very few case studies available. Yet, because of the OP-UG interactions; the operation has a higher safety, technical and management requirements than the OP or UG methods when considered separately. In Vietnam, Cao Son is one of many OP mines, which decided to change the operational system from OP to UG. Simultaneous operation started in 2015 and will be conducted until 2030 when the OP mine Cao Son ends its mining activities. In this paper, selected geomechanical considerations of the simultaneous operation are presented. A number of numerical modelling calculations using finitedifference software with code FLAC were carried out for calibration process, slope stability analysis and the OP-UG interaction analysis for the Cao Son - Khe Cham II-IV mine. Based on the results obtained from numerical modelling, the geomechanical assessments of simultaneous operation Cao Son - Khe Cham II-IV are discussed in this paper.

Influence of loading and heating processes on elastic and geomechanical properties of eclogites and granulites

Directory of Open Access Journals (Sweden)

Hem Bahadur Motra

2018-02-01

Full Text Available Increased knowledge of the elastic and geomechnical properties of rocks is important for numerous engineering and geoscience applications (e.g. petroleum geoscience, underground waste repositories, geothermal energy, earthquake studies, and hydrocarbon exploration. To assess the effect of pressure and temperature on seismic velocities and their anisotropy, laboratory experiments were conducted on metamorphic rocks. P- (Vp and S-wave (Vs velocities were determined on cubic samples of granulites and eclogites with an edge length of 43 mm in a triaxial multianvil apparatus using the ultrasonic pulse emission technique in dependence of changes in pressure and temperature. At successive isotropic pressure states up to 600 MPa and temperatures up to 600 °C, measurements were performed related to the sample coordinates given by the three principal fabric directions (x, y, z representing the foliation (xy-plane, the normal to the foliation (z-direction, and the lineation direction (x-direction. Progressive volumetric strain was logged by the discrete piston displacements. Cumulative errors in Vp and Vs are estimated to be <1%. Microcrack closure significantly contributes to the increase in seismic velocities and decrease in anisotropies for pressures up to 200–250 MPa. Characteristic P-wave anisotropies of about 10% are obtained for eclogite and 3–4% in a strongly retrogressed eclogite as well as granulites. The wave velocities were used to calculate the geomechanical properties (e.g. density, Poisson's ratio, volumetric strain, and elastic moduli at different pressure and temperature conditions. These results contribute to the reliable estimate of geomechanical properties of rocks.

Microstructures imply cataclasis and authigenic mineral formation control geomechanical properties of New Zealand's Alpine Fault

Science.gov (United States)

Schuck, B.; Janssen, C.; Schleicher, A. M.; Toy, V. G.; Dresen, G.

2018-05-01

The Alpine Fault is capable of generating large (MW > 8) earthquakes and is the main geohazard on South Island, NZ, and late in its 250-291-year seismic cycle. To minimize its hazard potential, it is indispensable to identify and understand the processes influencing the geomechanical behavior and strength-evolution of the fault. High-resolution microstructural, mineralogical and geochemical analyses of the Alpine Fault's core demonstrate wall rock fragmentation, assisted by mineral dissolution, and cementation resulting in the formation of a fine-grained principal slip zone (PSZ). A complex network of anastomosing and mutually cross-cutting calcite veins implies that faulting occurred during episodes of dilation, slip and sealing. Fluid-assisted dilatancy leads to a significant volume increase accommodated by vein formation in the fault core. Undeformed euhedral chlorite crystals and calcite veins that have cut footwall gravels demonstrate that these processes occurred very close to the Earth's surface. Microstructural evidence indicates that cataclastic processes dominate the deformation and we suggest that powder lubrication and grain rolling, particularly influenced by abundant nanoparticles, play a key role in the fault core's velocity-weakening behavior rather than frictional sliding. This is further supported by the absence of smectite, which is reasonable given recently measured geothermal gradients of more than 120 °C km-1 and the impermeable nature of the PSZ, which both limit the growth of this phase and restrict its stability to shallow depths. Our observations demonstrate that high-temperature fluids can influence authigenic mineral formation and thus control the fault's geomechanical behavior and the cyclic evolution of its strength.

Geophysical Monitoring of Coupled Microbial and Geochemical Processes During Stimulated Subsurface Bioremediation

International Nuclear Information System (INIS)

Williams, Kenneth H.; Kemna, Andreas; Wilkins, Michael J.; Druhan, Jennifer L.; Arntzen, Evan V.; N'Guessan, A. Lucie; Long, Philip E.; Hubbard, Susan S.; Banfield, Jillian F.

2009-01-01

Understanding how microorganisms alter their physical and chemical environment during bioremediation is hindered by our inability to resolve subsurface microbial activity with high spatial resolution. Here we demonstrate the use of a minimally invasive geophysical technique to monitor stimulated microbial activity during acetate amendment in an aquifer near Rifle, Colorado. During electrical induced polarization (IP) measurements, spatiotemporal variations in the phase response between imposed electric current and the resultant electric field correlated with changes in groundwater geochemistry accompanying stimulated iron and sulfate reduction and sulfide mineral precipitation. The magnitude of the phase response varied with measurement frequency (0.125 and 1 Hz) and was dependent upon the dominant metabolic process. The spectral effect was corroborated using a biostimulated column experiment containing Rifle sediments and groundwater. Fluids and sediments recovered from regions exhibiting an anomalous phase response were enriched in Fe(II), dissolved sulfide, and cell-associated FeS nanoparticles. The accumulation of mineral precipitates and electroactive ions altered the ability of pore fluids to conduct electrical charge, accounting for the anomalous IP response and revealing the usefulness of multifrequency IP measurements for monitoring mineralogical and geochemical changes accompanying stimulated subsurface bioremediation

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

CERN Document Server

Smerd, S F

1969-01-01

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

Organic geochemistry of Czech amber

Czech Academy of Sciences Publication Activity Database

Havelcová, Martina; Sýkorová, Ivana; Mach, K.; Dvořák, Z.

2015-01-01

Roč. 11, č. 1 (2015), s. 146 ISSN 1336-7242. [Zjazd chemikov /67./. 07.09.2015-11.09.2015, Horný Smokovec] R&D Projects: GA ČR(CZ) GA13-18482S Institutional research plan: CEZ:AV0Z30460519 Keywords : fossil resin * amber * resinite Subject RIV: DD - Geochemistry

Assessment of geomechanical properties, maximum depth and excavation damaged zone aspects - Expert report

International Nuclear Information System (INIS)

Amann, F.; Löw, S.; Perras, M.

2015-11-01

This comprehensive report published by the Swiss National Nuclear Safety Inspectorate ENSI discusses the expert report published on the need for the assessment of geomechanical properties and maximum depth of repositories for high, medium and low-activity nuclear wastes. Also, aspects concerning excavation damaged zones (EDZ) are considered. These are all criteria for the selection of sites as part of Phase 2 of the Swiss waste disposal project. Four questions are examined: are NAGRA’s documented basic considerations and calculations on Opalinus Clay comprehensive enough and correct, are the calculations on maximum depth correct, are the proposed storage perimeters correct with respect to depth and will NAGRA be able to take possible excavation damaged zones (EDZ) into account? Literature and references concerning the subject are quoted

Geophysical images of basement rocks. Geophysical images in the Guianese basement. Airborne geophysical campaign in French Guiana - 1996

International Nuclear Information System (INIS)

Delor, C.; Perrin, J.; Truffert, C.; Asfirane, F.; Rossi, Ph.; Bonjoly, D.; Dubreuihl, J.; Chardon, D.

1998-01-01

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

Geoscience data base handbook for modeling a nuclear waste repository. Volume 1

International Nuclear Information System (INIS)

Isherwood, D.

1979-12-01

This handbook contains reference information on parameters that should be considered in analyzing or modeling a proposed nuclear waste repository site. Only those parameters and values that best represent the natural environment are included. Rare extremes are avoided. Where laboratory and field data are inadequate, theoretical treatments and informed engineering judgements are presented. Volume 1 contains a data base on salt as a repository medium. Chapters on the geology of bedded and dome salt, the geomechanics of salt, hydrology, geochemistry, natural and man-made features, and seismology provide compiled data and related information useful for studying a proposed repository in salt. These and other data will be needed to derive generic deep geologic modeling parameters and will also serve as background for the verification of source data that may be presented in licensing applications for nuclear waste repositories. Volume 2 is the result of a scoping study for a data base on the geology, geomechanics, and hydrology of shale, granite, and basalt as alternative repository media. Except for the geomechanics of shale, most of the sections contain relatively complete compilations of the available data, as well as discussions of the properties that are unique to each rock type

Introduction to the JEEG Agricultural Geophysics Special Issue

Science.gov (United States)

Allred, Barry J.; Smith, Bruce D.

2010-01-01

Near-surface geophysical methods have become increasingly important tools in applied agricultural practices and studies. The great advantage of geophysical methods is their potential rapidity, low cost, and spatial continuity when compared to more traditional methods of assessing agricultural land, such as sample collection and laboratory analysis. Agricultural geophysics investigations commonly focus on obtaining information within the soil profile, which generally does not extend much beyond 2 meters beneath the ground surface. Although the depth of interest oftentimes is rather shallow, the area covered by an agricultural geophysics survey can vary widely in scale, from experimental plots (10 s to 100 s of square meters), to farm fields (10 s to 100 s of hectares), up to the size of watersheds (10 s to 100 s of square kilometers). To date, three predominant methods—resistivity, electromagnetic induction (EMI), and ground-penetrating radar (GPR)—have been used to obtain surface-based geophysical measurements within agricultural settings. However, a recent conference on agricultural geophysics (Bouyoucos Conference on Agricultural Geophysics, September 8–10, 2009, Albuquerque, New Mexico; www.ag-geophysics.org) illustrated that other geophysical methods are being applied or developed. These include airborne electromagnetic induction, magnetometry, seismic, and self-potential methods. Agricultural geophysical studies are also being linked to ground water studies that utilize deeper penetrating geophysical methods than normally used.

The genetics of geochemistry

OpenAIRE

Croal, Laura R.; Gralnick, Jeffrey A.; Malasarn, Davin; Newman, Dianne K.

2004-01-01

Bacteria are remarkable in their metabolic diversity due to their ability to harvest energy from myriad oxidation and reduction reactions. In some cases, their metabolisms involve redox transformations of metal(loid)s, which lead to the precipitation, transformation, or dissolution of minerals. Microorganism/mineral interactions not only affect the geochemistry of modern environments, but may also have contributed to shaping the near-surface environment of the early Earth. For example, bacter...

Geophysical Institute. Biennial report, 1993-1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-01-01

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

Arbitrary Lagrangian-Eulerian method for non-linear problems of geomechanics

International Nuclear Information System (INIS)

Nazem, M; Carter, J P; Airey, D W

2010-01-01

In many geotechnical problems it is vital to consider the geometrical non-linearity caused by large deformation in order to capture a more realistic model of the true behaviour. The solutions so obtained should then be more accurate and reliable, which should ultimately lead to cheaper and safer design. The Arbitrary Lagrangian-Eulerian (ALE) method originated from fluid mechanics, but has now been well established for solving large deformation problems in geomechanics. This paper provides an overview of the ALE method and its challenges in tackling problems involving non-linearities due to material behaviour, large deformation, changing boundary conditions and time-dependency, including material rate effects and inertia effects in dynamic loading applications. Important aspects of ALE implementation into a finite element framework will also be discussed. This method is then employed to solve some interesting and challenging geotechnical problems such as the dynamic bearing capacity of footings on soft soils, consolidation of a soil layer under a footing, and the modelling of dynamic penetration of objects into soil layers.

Predictive geophysics: geochemical simulations to geophysical targets

Science.gov (United States)

Chopping, R. G.; Cleverley, J.

2017-12-01

With an increasing focus on deep exploration for covered targets, new methods are required to target mineral systems under cover. Geophysical responses are driven by physical property contrasts; for example, density contrasts provide a gravity signal, acoustic impedance contrasts provide a seismic reflection signal. In turn, the physical properties for basement, crystalline rocks which host the vast majority of mineral systems are determined almost wholly by the mineralogy of the rocks in question. Mineral systems, through the transport of heat and reactive fluids, will serve to modify the physical properties of country rock as they chemically alter the hosting strata. To understand these changes, we have performed 2D reactive transport modelling that simulates the formation of Archean gold deposits of the Yilgarn Craton, Western Australia. From this, we derive a model of mineralogy that we can use to predict the density, magnetic susceptibility and seismic reflection changes associated with ore formation. It is then possible to predict the gravity, magnetic and seismic reflection responses associated with these deposits. Scenario mapping, such as testing the ability to resolve buried ore bodies or the geophysical survey spacing required to resolve the mineral system, can be performed to produce geophysical targets from these geochemical simulations. We find that there is a gravity response of around 9% of the unaltered response for deposits even buried by 1km of cover, and there is a magnetic spike associated with proximal alteration of the ore system. Finally, seismic reflection response is mostly characterised by additional reflections along faults that plumb the alteration system.

Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods

Energy Technology Data Exchange (ETDEWEB)

Keating, Kristina [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Slater, Lee [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Ntarlagiannis, Dimitris [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Williams, Kenneth H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division

2015-02-24

This documents contains the final report for the project "Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods" (DE-SC0007049) Executive Summary: Our research aimed to develop borehole measurement techniques capable of monitoring subsurface processes, such as changes in pore geometry and iron/sulfur geochemistry, associated with remediation of heavy metals and radionuclides. Previous work has demonstrated that geophysical method spectral induced polarization (SIP) can be used to assess subsurface contaminant remediation; however, SIP signals can be generated from multiple sources limiting their interpretation value. Integrating multiple geophysical methods, such as nuclear magnetic resonance (NMR) and magnetic susceptibility (MS), with SIP, could reduce the ambiguity of interpretation that might result from a single method. Our research efforts entails combining measurements from these methods, each sensitive to different mineral forms and/or mineral-fluid interfaces, providing better constraints on changes in subsurface biogeochemical processes and pore geometries significantly improving our understanding of processes impacting contaminant remediation. The Rifle Integrated Field Research Challenge (IFRC) site was used as a test location for our measurements. The Rifle IFRC site is located at a former uranium ore-processing facility in Rifle, Colorado. Leachate from spent mill tailings has resulted in residual uranium contamination of both groundwater and sediments within the local aquifer. Studies at the site include an ongoing acetate amendment strategy, native microbial populations are stimulated by introduction of carbon intended to alter redox conditions and immobilize uranium. To test the geophysical methods in the field, NMR and MS logging measurements were collected before, during, and after acetate amendment. Next, laboratory NMR, MS, and SIP measurements

A review of nuclear geophysics

International Nuclear Information System (INIS)

Clayton, C.G.; Schweitzer, J.S.

1992-01-01

This paper summarizes the development of nuclear geophysics in scientific and technological content and in range from its beginnings early in this century to the present day. We note that the early work in nuclear geophysics was originally referred to under the umbrella of open-quotes isotope applicationsclose quotes and the origin of the term open-quotes nuclear geophysicsclose quotes (which is seen to clarify and to focus work in this area) is exposed in this paper. The current expansion of nuclear geophysics front its original concern with oil well logging is an important trend because much of the underlying science, technology, and instrumentation is common ground. A review of nuclear geophysics would be a barren document without reference to long-term and, in some cases, short-term commercial and economic as well as to technological considerations, since these factors are the principal motivation for further development

Geological and geomechanical properties of the carbonate rocks at the eastern Black Sea Region (NE Turkey)

Science.gov (United States)

Ersoy, Hakan; Yalçinalp, Bülent; Arslan, Mehmet; Babacan, Ali Erden; Çetiner, Gözde

2016-11-01

Turkey located in the Alpine-Himalayan Mountain Belt has 35% of the natural stone reserves of the world and has good quality marble, limestone, travertine and onyx reserves especially in the western regions of the country. The eastern Black Sea Region with a 1.4 million meters cubes reserve has a little role on the natural stone production in the country. For this reason, this paper deals with investigation on the potential of carbonate stone in the region and determination of the geological and geo-mechanical properties of these rocks in order to provide economic contribution to the national economy. While the study sites are selected among the all carbonate rock sites, the importance as well as the representative of the sites were carefully considered for the region. After representative samples were analyzed for major oxide and trace element compositions to find out petrochemical variations, the experimental program conducted on rock samples for determination of both physical and strength properties of the carbonate rocks. The results of the tests showed that there are significant variations in the geo-mechanical properties of the studied rock groups. The density values vary from 2.48 to 2.70 gr/cm3, water absorption by weight values range from 0.07 to 1.15% and the apparent porosity of the carbonate rocks are between 0.19 and 3.29%. However, the values of the UCS shows variation from 36 to 80 MPa. Tensile and bending strength values range from 3.2 to 7.5 MPa and 6.0-9.2 MPa respectively. Although the onyx samples have the lowest values of apparent porosity and water absorption by weight, these samples do not have the highest values of UCS values owing to occurrence of the micro-cracks. The UCS values of the rock samples were also found after cycling tests However, the limestone samples have less than 5% deterioration after freezing-thawing and wetting-drying tests, but travertine and onyx samples have more than 15% deterioration. Exception of the apparent

Geochemistry of groundwater in the Beaver and Camas Creek drainage basins, eastern Idaho

Science.gov (United States)

Rattray, Gordon W.; Ginsbach, Michael L.

2014-01-01

The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, is studying the fate and transport of waste solutes in the eastern Snake River Plain (ESRP) aquifer at the Idaho National Laboratory (INL) in eastern Idaho. This effort requires an understanding of the natural and anthropogenic geochemistry of groundwater at the INL and of the important physical and chemical processes controlling the geochemistry. In this study, the USGS applied geochemical modeling to investigate the geochemistry of groundwater in the Beaver and Camas Creek drainage basins, which provide groundwater recharge to the ESRP aquifer underlying the northeastern part of the INL. Data used in this study include petrology and mineralogy from 2 sediment and 3 rock samples, and water-quality analyses from 4 surface-water and 18 groundwater samples. The mineralogy of the sediment and rock samples was analyzed with X-ray diffraction, and the mineralogy and petrology of the rock samples were examined in thin sections. The water samples were analyzed for field parameters, major ions, silica, nutrients, dissolved organic carbon, trace elements, tritium, and the stable isotope ratios of hydrogen, oxygen, carbon, sulfur, and nitrogen. Groundwater geochemistry was influenced by reactions with rocks of the geologic terranes—carbonate rocks, rhyolite, basalt, evaporite deposits, and sediment comprised of all of these rocks. Agricultural practices near and south of Dubois and application of road anti-icing liquids on U.S. Interstate Highway 15 were likely sources of nitrate, chloride, calcium, and magnesium to groundwater. Groundwater geochemistry was successfully modeled in the alluvial aquifer in Camas Meadows and the ESRP fractured basalt aquifer using the geochemical modeling code PHREEQC. The primary geochemical processes appear to be precipitation or dissolution of calcite and dissolution of silicate minerals. Dissolution of evaporite minerals, associated with Pleistocene Lake

Geochemistry of sulphur in petroleum systems

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Orr, W.L.

1990-01-01

A renaissance in the 1980s concerning geochemistry of sulfur in fossil fuels makes an update of the subject timely. Papers developed from the 1989 ACS Symposium in Dallas provide a cross-section of recent research and progress in our understanding of the abundance and nature of organically bound

A fractured rock geophysical toolbox method selection tool

Science.gov (United States)

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

2016-01-01

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

Informing groundwater models with near-surface geophysical data

DEFF Research Database (Denmark)

Herckenrath, Daan

Over the past decade geophysical methods have gained an increased popularity due to their ability to map hydrologic properties. Such data sets can provide valuable information to improve hydrologic models. Instead of using the measured geophysical and hydrologic data simultaneously in one inversion...... approach, many of the previous studies apply a Sequential Hydrogeophysical Inversion (SHI) in which inverted geophysical models provide information for hydrologic models. In order to fully exploit the information contained in geophysical datasets for hydrological purposes, a coupled hydrogeophysical...... inversion was introduced (CHI), in which a hydrologic model is part of the geophysical inversion. Current CHI-research has been focussing on the translation of simulated state variables of hydrologic models to geophysical model parameters. We refer to this methodology as CHI-S (State). In this thesis a new...

Multiscale geophysical imaging of the critical zone

Science.gov (United States)

Parsekian, Andy; Singha, Kamini; Minsley, Burke J.; Holbrook, W. Steven; Slater, Lee

2015-01-01

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

Methodological Developments in Geophysical Assimilation Modeling

Science.gov (United States)

Christakos, George

2005-06-01

This work presents recent methodological developments in geophysical assimilation research. We revisit the meaning of the term "solution" of a mathematical model representing a geophysical system, and we examine its operational formulations. We argue that an assimilation solution based on epistemic cognition (which assumes that the model describes incomplete knowledge about nature and focuses on conceptual mechanisms of scientific thinking) could lead to more realistic representations of the geophysical situation than a conventional ontologic assimilation solution (which assumes that the model describes nature as is and focuses on form manipulations). Conceptually, the two approaches are fundamentally different. Unlike the reasoning structure of conventional assimilation modeling that is based mainly on ad hoc technical schemes, the epistemic cognition approach is based on teleologic criteria and stochastic adaptation principles. In this way some key ideas are introduced that could open new areas of geophysical assimilation to detailed understanding in an integrated manner. A knowledge synthesis framework can provide the rational means for assimilating a variety of knowledge bases (general and site specific) that are relevant to the geophysical system of interest. Epistemic cognition-based assimilation techniques can produce a realistic representation of the geophysical system, provide a rigorous assessment of the uncertainty sources, and generate informative predictions across space-time. The mathematics of epistemic assimilation involves a powerful and versatile spatiotemporal random field theory that imposes no restriction on the shape of the probability distributions or the form of the predictors (non-Gaussian distributions, multiple-point statistics, and nonlinear models are automatically incorporated) and accounts rigorously for the uncertainty features of the geophysical system. In the epistemic cognition context the assimilation concept may be used to

Impact of hydrogeological and geomechanical properties on surface uplift at a CO2 injection site: Parameter estimation and uncertainty quantification

Science.gov (United States)

Newell, P.; Yoon, H.; Martinez, M. J.; Bishop, J. E.; Arnold, B. W.; Bryant, S.

2013-12-01

It is essential to couple multiphase flow and geomechanical response in order to predict a consequence of geological storage of CO2. In this study, we estimate key hydrogeologic features to govern the geomechanical response (i.e., surface uplift) at a large-scale CO2 injection project at In Salah, Algeria using the Sierra Toolkit - a multi-physics simulation code developed at Sandia National Laboratories. Importantly, a jointed rock model is used to study the effect of postulated fractures in the injection zone on the surface uplift. The In Salah Gas Project includes an industrial-scale demonstration of CO2 storage in an active gas field where CO2 from natural gas production is being re-injected into a brine-filled portion of the structure downdip of the gas accumulation. The observed data include millimeter scale surface deformations (e.g., uplift) reported in the literature and injection well locations and rate histories provided by the operators. Our preliminary results show that the intrinsic permeability and Biot coefficient of the injection zone are important. Moreover pre-existing fractures within the injection zone affect the uplift significantly. Estimation of additional (i.e., anisotropy ratio) and coupled parameters will help us to develop models, which account for the complex relationship between mechanical integrity and CO2 injection-induced pressure changes. Uncertainty quantification of model predictions will be also performed using various algorithms including null-space Monte Carlo and polynomial-chaos expansion methods. This work will highlight that our coupled reservoir and geomechanical simulations associated with parameter estimation can provide a practical solution for designing operating conditions and understanding subsurface processes associated with the CO2 injection. This work is supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office

Geophysics and geochemistry intertwined: Modeling the internal evolution of Ceres, Pluto, and Charon

Science.gov (United States)

Neveu, Marc; Desch, Steven J.; Castillo-Rogez, Julie C.

2015-11-01

Liquid water likely shaped dwarf planet evolution: observations [1,2] and models [3-5] suggest aqueous alteration of silicates or volatiles accreted by these worlds. Driven by thermo-physical settings, aqueous alteration also feeds back on dwarf planet evolution in unconstrained ways. Can rocky dwarf planet cores crack, increasing the water-rock interface? Might radionuclides be leached into fluids, changing the distribution of this chief heat source? What is the fate of antifreezes, on which may hinge long-term liquid persistence? Is volcanism favored or impeded? What are predicted cryomagma compositions?We have modeled silicate core fracturing [6], geochemical equilibria between chondritic rock and aqueous fluids [7], and prerequisites for cryovolcanism [8]. These models, coupled to an evolution code [3], allow us to study geophysics/chemistry feedbacks inside dwarf planets.Ice-rock differentiation, even partial [9,10], yields a rocky, brittle core cracked by thermal stresses; liquid circulation through core cracks transports heat into the ice mantle, yielding runaway melting that quickly ceases once convection cools the mantle to its freezing point [6]. Hot fluids can leach radionuclides at high water:rock ratios (W:R); NH3 antifreeze can turn into NH4-minerals at low W:R [7]. Volatile (chiefly CO) exsolution enables explosive cryovolcanism [8]; this may explain Pluto’s young, CO-rich Tombaugh Regio.Applied to Ceres, such models are consistent with pre-Dawn and Dawn data [11] provided Ceres partially differentiated into a rocky core and muddy mantle [10]. They suggest Ceres’ hydrated surface [2] was emplaced during a 26Al-fueled active phase, and predict its bright spots result from cryovolcanic fluids squeezed by mantle refreezing and effusing through pre-existing subsurface cracks [11].[1] Cook et al. 2007 ApJ 663:1406[2] Milliken & Rivkin 2009 Nat Geosc 2:258[3] Desch et al. 2009 Icarus 202:694[4] Castillo-Rogez et al. 2010 Icarus 205:443[5] Robuchon

RESOLUTION STRATEGY FOR GEOMECHANICALLY-RELATED REPOSITORY DESIGN FOR THERMAL-MECHANICAL EFFECTS (RDTME)

International Nuclear Information System (INIS)

Board, M.

2003-01-01

In September of 2000, the U.S. Nuclear Regulatory Commission (NRC) issued an Issue Resolution Status Report (NRC 2000). The Key Technical Issue (KTI) agreements on Repository Design and Thermal-Mechanical Effects (RDTME) were jointly developed at the Technical Exchange and Management Meeting held on February 6-8, 2001 in Las Vegas, Nevada. In that report, a number of geomechanically-related issues were raised regarding the determination of rock properties, the estimation of the impacts of geologic variability, the use of numerical models, and the examination of drift degradation and design approach to the ground support system for the emplacement drifts. Ultimately, the primary end products of the KTI agreement resolution processes are an assessment of the preclosure stability of emplacement drifts and the associated ground support requirements. There is also an assessment of the postclosure degradation of the excavations when subjected to thermal and seismic-related stresses as well as in situ loading over time

Engineered barrier system and waste package design concepts for a potential geologic repository at Yucca Mountain

International Nuclear Information System (INIS)

Short, D.W.; Ruffner, D.J.; Jardine, L.J.

1991-10-01

We are using an iterative process to develop preliminary concept descriptions for the Engineered Barrier System and waste-package components for the potential geologic repository at Yucca Mountain. The process allows multiple design concepts to be developed subject to major constraints, requirements, and assumptions. Involved in the highly interactive and interdependent steps of the process are technical specialists in engineering, metallic and nonmetallic materials, chemistry, geomechanics, hydrology, and geochemistry. We have developed preliminary design concepts that satisfy both technical and nontechnical (e.g., programmatic or policy) requirements

36 CFR 902.59 - Geological and geophysical information.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical information. 902.59 Section 902.59 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT... Geological and geophysical information. Any geological or geophysical information and data (including maps...

Numerical Simulation of Permeability Change in Wellbore Cement Fractures after Geomechanical Stress and Geochemical Reactions Using X-ray Computed Tomography Imaging.

Science.gov (United States)

Kabilan, Senthil; Jung, Hun Bok; Kuprat, Andrew P; Beck, Anthon N; Varga, Tamas; Fernandez, Carlos A; Um, Wooyong

2016-06-21

X-ray microtomography (XMT) imaging combined with three-dimensional (3D) computational fluid dynamics (CFD) modeling technique was used to study the effect of geochemical and geomechanical processes on fracture permeability in composite Portland cement-basalt caprock core samples. The effect of fluid density and viscosity and two different pressure gradient conditions on fracture permeability was numerically studied by using fluids with varying density and viscosity and simulating two different pressure gradient conditions. After the application of geomechanical stress but before CO2-reaction, CFD revealed fluid flow increase, which resulted in increased fracture permeability. After CO2-reaction, XMT images displayed preferential precipitation of calcium carbonate within the fractures in the cement matrix and less precipitation in fractures located at the cement-basalt interface. CFD estimated changes in flow profile and differences in absolute values of flow velocity due to different pressure gradients. CFD was able to highlight the profound effect of fluid viscosity on velocity profile and fracture permeability. This study demonstrates the applicability of XMT imaging and CFD as powerful tools for characterizing the hydraulic properties of fractures in a number of applications like geologic carbon sequestration and storage, hydraulic fracturing for shale gas production, and enhanced geothermal systems.

An overview on geochemistry of Proterozoic massif-type ...

Indian Academy of Sciences (India)

A critical study of 311 published WR chemical analyses, isotopic and mineral chemistry of ... Keywords. Massif anorthosite complexes; overview; geochemistry; high-Al gabbro. J. Earth ...... (123–2920 ppm) unlike the experimental results of.

Constructing reservoir-scale 3D geomechanical FE-models. A refined workflow for model generation and calculation

Energy Technology Data Exchange (ETDEWEB)

Fischer, K.; Henk, A. [Technische Univ. Darmstadt (Germany). Inst. fuer Angewandte Geowissenschaften

2013-08-01

The tectonic stress field strongly affects the optimal exploitation of conventional and unconventional hydrocarbon reservoirs. Amongst others, wellbore stability, orientation of hydraulically induced fractures and - particularly in fractured reservoirs - permeability anisotropies depend on the magnitudes and orientations of the recent stresses. Geomechanical reservoir models can provide unique insights into the tectonic stress field revealing the local perturbations resulting from faults and lithological changes. In order to provide robust predictions, such numerical models are based on the finite element (FE) method and account for the complexities of real reservoirs with respect to subsurface geometry, inhomogeneous material distribution and nonlinear rock mechanical behavior. We present a refined workflow for geomechanical reservoir modeling which allows for an easier set-up of the model geometry, high resolution submodels and faster calculation times due to element savings in the load frame. Transferring the reservoir geometry from the geological subsurface model, e.g., a Petrel {sup registered} project, to the FE model represents a special challenge as the faults are discontinuities in the numerical model and no direct interface exists between the two software packages used. Point clouds displaying faults and lithostratigraphic horizons can be used for geometry transfer but this labor-intensive approach is not feasible for complex field-scale models with numerous faults. Instead, so-called Coon's patches based on horizon lines, i.e. the intersection lines between horizons and faults, are well suited to re-generate the various surfaces in the FE software while maintaining their topology. High-resolution submodels of individual fault blocks can be incorporated into the field-scale model. This allows to consider both a locally refined mechanical stratigraphy and the impact of the large-scale fault pattern. A pressure load on top of the model represents the

25 CFR 211.56 - Geological and geophysical permits.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 211.56 Section 211.56... FOR MINERAL DEVELOPMENT Rents, Royalties, Cancellations and Appeals § 211.56 Geological and geophysical permits. Permits to conduct geological and geophysical operations on Indian lands which do not...

Objective computerized approaches for centralized geophysical and geochemical landscape project planning.

Directory of Open Access Journals (Sweden)

Danilyan Eugene Andreevich

2013-10-01

Full Text Available At present landscape design does not represent a scientific subject in strict sense, being a superposition of decorative and applied landscape art and the methods of graphic architectural planning. Serving interests of customers, it does not harmonize with the individual needs of the ground based on landscape geochemistry and ecology. Hence, it results in great number of grounds not consistent with each other according to geochemical criteria. In many cases total soil changing, isolation of natural hydrodynamic drainage, introduction of exotic plants interacting with their environment (including abiotic relations take place, it results in disequilibrium in the ground. Ecological system efficiency needs to be constantly artificially maintained, and that does not support its stability. In other words, without maintaining sufficient conditions, it will be influenced by succession with the course of time, as a particular case of potential gradient equalization. Hence, at present there is an acute problem to develop such a concept of landscape design, that, covering ecological requirements of customers, would be mass one, not producing gradient isolation effect and ecologically self-sustaining in given environment at the same time. It is evident, that to meet these requirements, this concept should not be the product of subjective vision of the author, but direct consequence of geophysical and geochemical landscape condition with theoretical development allowing calculation testing at any scale of geographical zoning.

The geochemistry of stable chlorine and bromine isotopes

Energy Technology Data Exchange (ETDEWEB)

Eggenkamp, Hans [Onderzock and Beleving, Bussum (Netherlands)

2014-11-01

First book solely dedicated to the geochemistry of chlorine and bromine isotopes. Detailed description of analytical techniques, including their advantages and disadvantages. Indication of research fields where measurement of these isotopes is especially useful. This book provides detailed information on the history, analysis and applications of chlorine and bromine isotope geochemistry. Chlorine and bromine are geochemically unique as they prefer to exist as single charged negative ions. For this reason isotope fractionation reflects mostly processes that are not related to changes in the redox state and this fractionation is generally modest. The book will describe the processes that are most easily detected using these isotopes. Also isotope variations, and processes that cause them, measured in oxidised species such as perchlorates and in organic molecules will be described in this book.

Geochemistry of zinc in the sediments of the western continental shelf and slope of India

Digital Repository Service at National Institute of Oceanography (India)

Murty, P.S.N.; Paropkari, A.L.; Rao, Ch.M.

The bulk geochemistry of zinc in the sediments of the western continental shelf and slope of India and also the partition geochemistry of the sediments of the shelf and slope regions between Ratnagiri and Mangalore have been studied. The studies...

Information needs for characterization of high-level waste repository sites in six geologic media. Volume 2. Appendices

Energy Technology Data Exchange (ETDEWEB)

NONE

1985-05-01

Volume II contains appendices for the following: (1) remote sensing and surface mapping techniques; (2) subsurface mapping methods for site characterization; (3) gravity technique; (4) audio-frequency magnetotelluric technique; (5) seismic refraction technique; (6) direct-current electrical resistivity method; (7) magnetic technique; (8) seismic reflection technique; (9) seismic crosshole method; (10) mechanical downhole seismic velocity survey method; (11) borehole geophysical logging techniques; (12) drilling and coring methods for precharacterization studies; (13) subsurface drilling methods for site characterization; (14) geomechanical/thermomechanical techniques for precharacterization studies; (15)geomechanical/thermal techniques for site characterization studies; (16) exploratory geochemical techniques for precharacterization studies; (17) geochemical techniques for site characterization; (18) hydrologic techniques for precharacterization studies; (19) hydrologic techniques for site characterization; and (20) seismological techniques.

Information needs for characterization of high-level waste repository sites in six geologic media. Volume 2. Appendices

International Nuclear Information System (INIS)

1985-05-01

Volume II contains appendices for the following: (1) remote sensing and surface mapping techniques; (2) subsurface mapping methods for site characterization; (3) gravity technique; (4) audio-frequency magnetotelluric technique; (5) seismic refraction technique; (6) direct-current electrical resistivity method; (7) magnetic technique; (8) seismic reflection technique; (9) seismic crosshole method; (10) mechanical downhole seismic velocity survey method; (11) borehole geophysical logging techniques; (12) drilling and coring methods for precharacterization studies; (13) subsurface drilling methods for site characterization; (14) geomechanical/thermomechanical techniques for precharacterization studies; (15)geomechanical/thermal techniques for site characterization studies; (16) exploratory geochemical techniques for precharacterization studies; (17) geochemical techniques for site characterization; (18) hydrologic techniques for precharacterization studies; (19) hydrologic techniques for site characterization; and (20) seismological techniques

25 CFR 212.56 - Geological and geophysical permits.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Geological and geophysical permits. 212.56 Section 212.56... FOR MINERAL DEVELOPMENT Rents, Royalties, Cancellations, and Appeals § 212.56 Geological and geophysical permits. (a) Permits to conduct geological and geophysical operations on Indian lands which do not...

10 CFR 960.4-2-2 - Geochemistry.

Science.gov (United States)

2010-01-01

... DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Postclosure Guidelines § 960.4-2-2 Geochemistry. (a) Qualifying condition. The present and... peak cumulative releases of radionuclides to the accessible environment by a factor of 10 as compared...

Rapid Geophysical Surveyor

International Nuclear Information System (INIS)

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

1993-01-01

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

The Virtual Geophysics Laboratory (VGL): Scientific Workflows Operating Across Organizations and Across Infrastructures

Science.gov (United States)

Cox, S. J.; Wyborn, L. A.; Fraser, R.; Rankine, T.; Woodcock, R.; Vote, J.; Evans, B.

2012-12-01

The Virtual Geophysics Laboratory (VGL) is web portal that provides geoscientists with an integrated online environment that: seamlessly accesses geophysical and geoscience data services from the AuScope national geoscience information infrastructure; loosely couples these data to a variety of gesocience software tools; and provides large scale processing facilities via cloud computing. VGL is a collaboration between CSIRO, Geoscience Australia, National Computational Infrastructure, Monash University, Australian National University and the University of Queensland. The VGL provides a distributed system whereby a user can enter an online virtual laboratory to seamlessly connect to OGC web services for geoscience data. The data is supplied in open standards formats using international standards like GeoSciML. A VGL user uses a web mapping interface to discover and filter the data sources using spatial and attribute filters to define a subset. Once the data is selected the user is not required to download the data. VGL collates the service query information for later in the processing workflow where it will be staged directly to the computing facilities. The combination of deferring data download and access to Cloud computing enables VGL users to access their data at higher resolutions and to undertake larger scale inversions, more complex models and simulations than their own local computing facilities might allow. Inside the Virtual Geophysics Laboratory, the user has access to a library of existing models, complete with exemplar workflows for specific scientific problems based on those models. For example, the user can load a geological model published by Geoscience Australia, apply a basic deformation workflow provided by a CSIRO scientist, and have it run in a scientific code from Monash. Finally the user can publish these results to share with a colleague or cite in a paper. This opens new opportunities for access and collaboration as all the resources (models

Geomechanical analyses to investigate wellbore/mine interactions in the Potash Enclave of Southeastern New Mexico.

Energy Technology Data Exchange (ETDEWEB)

Ehgartner, Brian L.; Bean, James E. (Sandia Staffing Alliance, LLC, Albuquerque, NM); Arguello, Jose Guadalupe, Jr.; Stone, Charles Michael

2010-04-01

Geomechanical analyses have been performed to investigate potential mine interactions with wellbores that could occur in the Potash Enclave of Southeastern New Mexico. Two basic models were used in the study; (1) a global model that simulates the mechanics associated with mining and subsidence and (2) a wellbore model that examines the resulting interaction impacts on the wellbore casing. The first model is a 2D approximation of a potash mine using a plane strain idealization for mine depths of 304.8 m (1000 ft) and 609.6 m (2000 ft). A 3D wellbore model then considers the impact of bedding plane slippage across single and double cased wells cemented through the Salado formation. The wellbore model establishes allowable slippage to prevent casing yield.

Unleashing Geophysics Data with Modern Formats and Services

Science.gov (United States)

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

2016-04-01

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

Description of geophysical data in the SKB database GEOTAB

International Nuclear Information System (INIS)

Sehlstedt, S.

1988-02-01

For the storage of different types of data collected by SKB a database called Geotab has been created. The following data are stored in the database: Background data, geological data, geophysical data, hydrogeological data, hydrochemical data. This report describes the data flow for different types of geophysical measurements. The descriptions start with measurements and end with the storage of data in Geotab. Each process and the resulting data volume is presented separately. The geophysical measurements have been divided into the following subjects: Geophysical ground surface measurements, profile measurements; geophysical ground surface measurements, grid net measurements; geophysical borehole logging; petrophysical measurements. Each group of measurements is described in an individual chapter. In each chapter several measuring techniques are described and each method has a data table and a flyleaf table in Geotab. (orig.)

Geochemistry and petrogenesis of Proterozoic granitic rocks from ...

Indian Academy of Sciences (India)

Geochemistry and petrogenesis of Proterozoic granitic ... This study presents the geochemical characteristics of granitic rocks located on the northern ... Frost and Frost 2013). ...... King P L, White A J R, Chappell B W and Allen C M 1997.

Acoustic emission/microseismic activity developed in rock materials. Petrophysical interpretation of the conditions of the geomechanical stability

International Nuclear Information System (INIS)

Montoto, M.

1984-01-01

The acoustic emission/microseismic activity, A.E./M.A., developed in rock materials under stress is described. Besides, equipment and procedures for appropriate monitoring, evaluation and location of A.E./M.A. sources are also presented. The geomechanical stability of stressed geologic materials and rock masses is evaluated by means of the petrophysical interpretation of the generated A.E./M.A. The Kaiser's effect can be used to evaluate the maximum tectonic stress who has affected a given rock massif. The fractographic study of the Stripa granite is included on account of the general interest in the high level radiactive wastes storage. Some other historic cases are also described. (author)

Calibration and Confirmation in Geophysical Models

Science.gov (United States)

Werndl, Charlotte

2016-04-01

For policy decisions the best geophysical models are needed. To evaluate geophysical models, it is essential that the best available methods for confirmation are used. A hotly debated issue on confirmation in climate science (as well as in philosophy) is the requirement of use-novelty (i.e. that data can only confirm models if they have not already been used before. This talk investigates the issue of use-novelty and double-counting for geophysical models. We will see that the conclusions depend on the framework of confirmation and that it is not clear that use-novelty is a valid requirement and that double-counting is illegitimate.

Fundamentals of Geophysics

Science.gov (United States)

Frohlich, Cliff

Choosing an intermediate-level geophysics text is always problematic: What should we teach students after they have had introductory courses in geology, math, and physics, but little else? Fundamentals of Geophysics is aimed specifically at these intermediate-level students, and the author's stated approach is to construct a text “using abundant diagrams, a simplified mathematical treatment, and equations in which the student can follow each derivation step-by-step.” Moreover, for Lowrie, the Earth is round, not flat—the “fundamentals of geophysics” here are the essential properties of our Earth the planet, rather than useful techniques for finding oil and minerals. Thus this book is comparable in both level and approach to C. M. R. Fowler's The Solid Earth (Cambridge University Press, 1990).

Geophysical and geochemical techniques for exploration of hydrocarbons and minerals

International Nuclear Information System (INIS)

Sittig, M.

1980-01-01

The detailed descriptive information in this book is based on 389 US patents that deal with geophysical and geochemical techniques useful for the exploration of hydrocarbons and minerals. Where it was necessary to round out the complete technological picture, a few paragraphs from cited government reports have been included. These techniques are used in prospecting for oil, coal, oil shale, tar sand and minerals. The patents are grouped under the following chapters: geochemical prospecting; geobiological prospecting; geophysical exploration; magnetic geophysical prospecting; gravitational geophysical prospecting; electrical geophysical prospecting; nuclear geophysical prospecting; seismic geophysical prospecting; and exploratory well drilling. This book serves a double purpose in that it supplies detailed technical information and can be used as a guide to the US patent literature in this field. By indicating all the information that is significant, and eliminating legal jargon and juristic phraseology, this book presents an advanced, industrially oriented review of modern methods of geophysical and geochemical exploration techniques

Geochemistry and Petrogenesis of Biabanak–Bafq Mafic Mgmatism ...

Indian Academy of Sciences (India)

59

13185-1494. Email: m_poshtkoohi@yahoo.com; Mobile No: +98 912 209 39 73 ...... petrologie et tectonique du precambrien et de sa couverture, Ph.D. thesis, universite ..... Applications of the 190Pt–186OS isotope system to geochemistry and.

Marine geophysical data management and presentation system

Digital Repository Service at National Institute of Oceanography (India)

Kunte, P.D.

) of the National Institute of Oceanography, Goa, India. GPDMPS is designed for the computerized storage retrieval and presentation of marine geophysical data and information. For the systematic management of geophysical data and information, GPDMPS is subdivided...

Historical foundations of chemical geology and geochemistry

NARCIS (Netherlands)

Manten, A.A.

1966-01-01

Roughly, the name chemical geology has been used for as long as chemistry has been applied in geology; the name geochemistry was introduced by Schönbein, in 1838. Whereas initially the names were often regarded as synonymous, in our century there is a tendency to make a distinction between the two

Applied Geochemistry Special Issue on Environmental geochemistry of modern mining

Science.gov (United States)

Seal, Robert R.; Nordstrom, D. Kirk

2015-01-01

Environmental geochemistry is an integral part of the mine-life cycle, particularly for modern mining. The critical importance of environmental geochemistry begins with pre-mining baseline characterization and the assessment of environmental risks related to mining, continues through active mining especially in water and waste management practices, and culminates in mine closure. The enhanced significance of environmental geochemistry to modern mining has arisen from an increased knowledge of the impacts that historical and active mining can have on the environment, and from new regulations meant to guard against these impacts. New regulations are commonly motivated by advances in the scientific understanding of the environmental impacts of past mining. The impacts can be physical, chemical, and biological in nature. The physical challenges typically fall within the purview of engineers, whereas the chemical and biological challenges typically require a multidisciplinary array of expertise including geologists, geochemists, hydrologists, microbiologists, and biologists. The modern mine-permitting process throughout most of the world now requires that potential risks be assessed prior to the start of mining. The strategies for this risk assessment include a thorough characterization of pre-mining baseline conditions and the identification of risks specifically related to the manner in which the ore will be mined and processed, how water and waste products will be managed, and what the final configuration of the post-mining landscape will be.In the Fall 2010, the Society of Economic Geologists held a short course in conjunction with the annual meeting of the Geological Society of America in Denver, Colorado (USA) to examine the environmental geochemistry of modern mining. The intent was to focus on issues that are pertinent to current and future mines, as opposed to abandoned mines, which have been the focus of numerous previous short courses. The geochemical

Ferromanganese nodules and their associated sediments from the Central Indian Ocean Basin: Rare earth element geochemistry

Digital Repository Service at National Institute of Oceanography (India)

Pattan, J.N.; Rao, Ch.M.; Migdisov, A.A.; Colley, S.; Higgs, N.C.; Demidenko, L.

FerromanganeseNodulesandtheirAssociatedSedimentsfromtheCentralIndianOceanBasin:RareEarthElementGeochemistry J.N.PATTANCH.M.RAONationalInstituteofOceanography,DonaPaula Goa,IndiaA.A.MIGDISOV InstituteofGeochemistry,RussianAcademyofSciencesMoscow,Russia S.COLLEY,N.C.HIGGSSouthamptonOceanographyCentre,EmpressDockSouthampton...

Geomechanics for interpreting SAGD monitoring using micro-seismicity and surface tiltmeters

International Nuclear Information System (INIS)

De Pater, H.; De Koning, J.; Maxwell, S.; Walters, D.

2008-01-01

This paper described a procedures for history matching surface movements resulting from the warm-up phases of a steam assisted gravity drainage (SAGD) project in Saskatchewan. Surface movements were measured using tilt meters that covered the area influenced by the steam injection processes. A thermal reservoir model was then coupled to a geo-mechanical model in order to calculate the surface movements. Surface heave was computed by matching a minimum curvature surface to the tilt vectors. Surface heave data were extracted in order to facilitate comparisons between observed and simulated heave. Injection constraints were defined from measured injection rates in order to match pressure histories. The study showed that the coupled model accurately interpreted monitoring data. Seismic signatures indicated strike slip and potential overthrust fault slippage or casing failures. Uplift was largest at the heel of the well. Results were explained by reservoir heterogeneities. Surface heave was accurately measured using the tiltmeters. Micro-seismic data were used to constrain failure mechanisms and provide information needed to identify conformance and potential cap rock breaches. It was concluded that the model can be used effectively to optimize injection conformance and recovery. 10 refs., 4 tabs., 28 figs

Modelling of underground geomechanical characteristics for electrophysical conversion of oil shale

International Nuclear Information System (INIS)

Bukharkin, A A; Koryashov, I A; Martemyanov, S M; Ivanov, A A

2015-01-01

Oil shale energy extraction is an urgent issue for modern science and technique. With the help of electrical discharge phenomena it is possible to create a new efficient technology for underground conversion of oil shale to shale gas and oil. This method is based on Joule heat in the rock volume. During the laboratory experiments the problem has arisen, when the significant part of a shale fragment is being heated, but the further heating is impossible due to specimen cracking. It leads to disruption in current flow and heat exchange. Evidently, in the underground conditions these failure processes will not proceed. Cement, clay and glass fiber/epoxy resin armature have been used for modelling of geomechanical underground conditions. Experiments have shown that the use of a reinforcing jacket makes it possible to convert a full rock fragment. Also, a thermal field extends radially from the centre of a tree-type structure, and it has an elliptic cross section shape. It is explained by the oil shale anisotropy connected with a rock laminar structure. Therefore, heat propagation is faster along the layers than across ones. (paper)

Basis for in-situ geomechanical testing at the Yucca Mountain site

International Nuclear Information System (INIS)

Board, M.

1989-07-01

This report presents an analysis of the in-situ geomechanical testing needs for the Exploratory Shaft (ES) test facility at the Yucca Mountain site in Nevada. The testing needs are derived from 10CFR60 regulations and simple thermomechanical canister- and room-scale numerical studies. The testing approach suggested is based on an ''iterative'' procedure of full-scale testing combined with numerical and empirical modeling. The testing suggested is based heavily on demonstration of excavation and thermal loading of full-scale repository excavations. Numerical and/or empirical models are compared to the full-scale response, allowing for adjustment of the model and evaluation of confidence in their predictive ability. Additional testing may be specified if confidence in prediction of the rock mass response is low. It is suggested that extensive drifting be conducted within the proposed repository area, including exploration of the bounding Drill Hole Wash and Imbricate fault structures, as well as the Ghost Dance fault. This approach is opposed to an a priori statistical specification of a number of ''point'' tests which attempt to measure a given property at a specific location. 40 refs., 49 figs., 6 tabs

Timelapse ultrasonic tomography for measuring damage localization in geomechanics laboratory tests.

Science.gov (United States)

Tudisco, Erika; Roux, Philippe; Hall, Stephen A; Viggiani, Giulia M B; Viggiani, Gioacchino

2015-03-01

Variation of mechanical properties in materials can be detected non-destructively using ultrasonic measurements. In particular, changes in elastic wave velocity can occur due to damage, i.e., micro-cracking and particles debonding. Here the challenge of characterizing damage in geomaterials, i.e., rocks and soils, is addressed. Geomaterials are naturally heterogeneous media in which the deformation can localize, so that few measurements of acoustic velocity across the sample are not sufficient to capture the heterogeneities. Therefore, an ultrasonic tomography procedure has been implemented to map the spatial and temporal variations in propagation velocity, which provides information on the damage process. Moreover, double beamforming has been successfully applied to identify and isolate multiple arrivals that are caused by strong heterogeneities (natural or induced by the deformation process). The applicability of the developed experimental technique to laboratory geomechanics testing is illustrated using data acquired on a sample of natural rock before and after being deformed under triaxial compression. The approach is then validated and extended to time-lapse monitoring using data acquired during plane strain compression of a sample including a well defined layer with different mechanical properties than the matrix.

Geomechanics for interpreting SAGD monitoring using micro-seismicity and surface tiltmeters

Energy Technology Data Exchange (ETDEWEB)

De Pater, H.; De Koning, J.; Maxwell, S. [Pinnacle Technologies, Calgary, AB (Canada); Walters, D. [Taurus Reservoir Solutions Ltd., Calgary, AB (Canada)

2008-10-15

This paper described a procedures for history matching surface movements resulting from the warm-up phases of a steam assisted gravity drainage (SAGD) project in Saskatchewan. Surface movements were measured using tilt meters that covered the area influenced by the steam injection processes. A thermal reservoir model was then coupled to a geo-mechanical model in order to calculate the surface movements. Surface heave was computed by matching a minimum curvature surface to the tilt vectors. Surface heave data were extracted in order to facilitate comparisons between observed and simulated heave. Injection constraints were defined from measured injection rates in order to match pressure histories. The study showed that the coupled model accurately interpreted monitoring data. Seismic signatures indicated strike slip and potential overthrust fault slippage or casing failures. Uplift was largest at the heel of the well. Results were explained by reservoir heterogeneities. Surface heave was accurately measured using the tiltmeters. Micro-seismic data were used to constrain failure mechanisms and provide information needed to identify conformance and potential cap rock breaches. It was concluded that the model can be used effectively to optimize injection conformance and recovery. 10 refs., 4 tabs., 28 figs.

Geophysical Research Facility

Data.gov (United States)

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

Contribution to uranium geochemistry in intrusive granites

International Nuclear Information System (INIS)

Coulomb, R.

1959-01-01

This work aims to define the position of a certain number of French granitic deposits within the field of the geochemistry of granites in general, and of the geochemistry of uranium in particular. The regions concerned are: - 3 French Hercynian ranges, in the Vendee, in Brittany and in the Morvan, - 1 African range, probably precambrian, of the Hoggar. For each range, the petrochemical framework is first of all determined and then the degree of chemical homogeneity of the rocks is evaluated. In the petrochemical groups thus obtained the geochemical behaviour of the uranium is studied. From a point of view of the geochemistry of the granites under investigation, a comparison of the laws of distribution of the major elements in the 4 ranges shows up a convergence of average composition which was not anticipated by geological and petrographic considerations alone. The statistical and geochemical distribution laws of the total uranium as a function of the petrochemical variations are established. A study of the chemical forms of uranium in the rocks has drawn an attention to the qualitative and quantitative importance of the fraction of this uranium soluble in dilute acids. We have therefore reconsidered on the one hand, the laws of distribution of the insoluble uranium, which represents essentially the uranium fixed in crystalline structures (zircon, allanite...), and we have justified on the other hand the interest presented by the soluble uranium: this, although more complex in character, presents a geochemical unity in post magmatic phenomena which makes possible to find a genetic connection between the uraniferous deposits and the intrusive massifs. Finally we have given a plan of the geochemical cycle of uranium, in which we hope to have provided some more accurate data on the igneous phase. (author) [fr

Plutonium and Americium Geochemistry at Hanford: A Site Wide Review

Energy Technology Data Exchange (ETDEWEB)

Cantrell, Kirk J.; Felmy, Andrew R.

2012-08-23

This report was produced to provide a systematic review of the state-of-knowledge of plutonium and americium geochemistry at the Hanford Site. The report integrates existing knowledge of the subsurface migration behavior of plutonium and americium at the Hanford Site with available information in the scientific literature regarding the geochemistry of plutonium and americium in systems that are environmentally relevant to the Hanford Site. As a part of the report, key research needs are identified and prioritized, with the ultimate goal of developing a science-based capability to quantitatively assess risk at sites contaminated with plutonium and americium at the Hanford Site and the impact of remediation technologies and closure strategies.

Introduction to geochemistry and its applications. Tome 2. Transfer of elements. Geochemical evolution of exogenous domains

International Nuclear Information System (INIS)

Hagemann, R.; Treuil, M.

1998-01-01

This second tome of the introduction to geochemistry and its applications is divided into 9 chapters dealing with: the chloro-fluoro-methanes as tracers of the oceanic circulation; the study of radioactive disequilibria and their applications; the submarine hydrothermal activity; geochemistry and diagenesis, example of the Trias and Lias of Ardeche (France); the chemistry of deep waters in granitic environment, application to the underground storage of radioactive wastes; the impact of volcanism on atmosphere chemistry; the role of methane and light hydrocarbons in the atmosphere; the challenges of carbon; and the polar caps as recorders of atmosphere geochemistry and climates. (J.S.)

Fluid-rock geochemical interaction for modelling calibration in geothermal exploration in Indonesia

Science.gov (United States)

Deon, Fiorenza; Barnhoorn, Auke; Lievens, Caroline; Ryannugroho, Riskiray; Imaro, Tulus; Bruhn, David; van der Meer, Freek; Hutami, Rizki; Sibarani, Besteba; Sule, Rachmat; Saptadij, Nenny; Hecker, Christoph; Appelt, Oona; Wilke, Franziska

2017-04-01

Indonesia with its large, but partially unexplored geothermal potential is one of the most interesting and suitable places in the world to conduct geothermal exploration research. This study focuses on geothermal exploration based on fluid-rock geochemistry/geomechanics and aims to compile an overview on geochemical data-rock properties from important geothermal fields in Indonesia. The research carried out in the field and in the laboratory is performed in the framework of the GEOCAP cooperation (Geothermal Capacity Building program Indonesia- the Netherlands). The application of petrology and geochemistry accounts to a better understanding of areas where operating power plants exist but also helps in the initial exploration stage of green areas. Because of their relevance and geological setting geothermal fields in Java, Sulawesi and the sedimentary basin of central Sumatra have been chosen as focus areas of this study. Operators, universities and governmental agencies will benefit from this approach as it will be applied also to new green-field terrains. By comparing the characteristic of the fluids, the alteration petrology and the rock geochemistry we also aim to contribute to compile an overview of the geochemistry of the important geothermal fields in Indonesia. At the same time the rock petrology and fluid geochemistry will be used as input data to model the reservoir fluid composition along with T-P parameters with the geochemical workbench PHREEQC. The field and laboratory data are mandatory for both the implementation and validation of the model results.

Proceedings of the 14. Symposium on Geology from Northeast

International Nuclear Information System (INIS)

1991-01-01

Works on geology, including topics about sedimentology, stratigraphy, paleontology, geomorphology, environmental, hydrogeology, petrology, geochemistry, geochronology, geophysics, geotectonics and structural geology are described in this symposium. (C.G.C.)

Artificial intelligence and dynamic systems for geophysical applications

CERN Document Server

Gvishiani, Alexei

2002-01-01

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

Radioactivity and geophysics

International Nuclear Information System (INIS)

Radvanyi, P.

1992-01-01

The paper recalls a few steps of the introduction of radioactivity in geophysics and astrophysics: contribution of radioelements to energy balance of the Earth, age of the Earth based on radioactive disintegration and the discovery of cosmic radiations

Review of geophysical characterization methods used at the Hanford Site

International Nuclear Information System (INIS)

GV Last; DG Horton

2000-01-01

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

Petrography and Geochemistry of the Proterozoic Sandstones of ...

Indian Academy of Sciences (India)

22

studied to infer their provenance, intensity of paleo-weathering and ... geochemistry of clastic sedimentary rocks is widely studied to the tectonic setting, ...... Dickinson, W. R., 1985 Interpreting provenance relations from detrital modes ..... Carboniferous clastic rocks in west Junggar, Xinjiang, China: a case from the Hala-alat.

Geophysical data fusion for subsurface imaging

International Nuclear Information System (INIS)

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

1993-08-01

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

geochemistry of ekenkpon and nkporo shales, calabar flank, se

African Journals Online (AJOL)

incorporated in the clay minerals of the shales. Also the values of .... analyzed for major oxides, trace elements and rare earth element .... Trace, and rare earth elements geochemistry ..... bearing source material, Ca is leached rapidly than Na.

Geochemistry and petrogenesis of Mesoproterozoic A-type granitoids from the Danish island of Bornholm, southern Fennoscandia

DEFF Research Database (Denmark)

Johansson, Åke; Waight, Tod Earle; Andersen, Tom

2016-01-01

Granitoids and gneisses from the Danish island of Bornholm have been investigated using whole rock geochemistry, Sr and Nd isotope geochemistry and Hf isotopes in zircon. Recent U–Pb dating shows that the rocks were formed during a short time interval at 1.45 to 1.46 Ga, penecontemporaneous...

Merging metagenomics and geochemistry reveals environmental controls on biological diversity and evolution.

Science.gov (United States)

Alsop, Eric B; Boyd, Eric S; Raymond, Jason

2014-05-28

The metabolic strategies employed by microbes inhabiting natural systems are, in large part, dictated by the physical and geochemical properties of the environment. This study sheds light onto the complex relationship between biology and environmental geochemistry using forty-three metagenomes collected from geochemically diverse and globally distributed natural systems. It is widely hypothesized that many uncommonly measured geochemical parameters affect community dynamics and this study leverages the development and application of multidimensional biogeochemical metrics to study correlations between geochemistry and microbial ecology. Analysis techniques such as a Markov cluster-based measure of the evolutionary distance between whole communities and a principal component analysis (PCA) of the geochemical gradients between environments allows for the determination of correlations between microbial community dynamics and environmental geochemistry and provides insight into which geochemical parameters most strongly influence microbial biodiversity. By progressively building from samples taken along well defined geochemical gradients to samples widely dispersed in geochemical space this study reveals strong links between the extent of taxonomic and functional diversification of resident communities and environmental geochemistry and reveals temperature and pH as the primary factors that have shaped the evolution of these communities. Moreover, the inclusion of extensive geochemical data into analyses reveals new links between geochemical parameters (e.g. oxygen and trace element availability) and the distribution and taxonomic diversification of communities at the functional level. Further, an overall geochemical gradient (from multivariate analyses) between natural systems provides one of the most complete predictions of microbial taxonomic and functional composition. Clustering based on the frequency in which orthologous proteins occur among metagenomes

Field Geophysics at SAGE: Strategies for Effective Education

Science.gov (United States)

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

2011-12-01

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

Application of Nonlinear Analysis Methods for Identifying Relationships Between Microbial Community Structure and Groundwater Geochemistry

International Nuclear Information System (INIS)

Schryver, Jack C.; Brandt, Craig C.; Pfiffner, Susan M.; Palumbo, A V.; Peacock, Aaron D.; White, David C.; McKinley, James P.; Long, Philip E.

2006-01-01

The relationship between groundwater geochemistry and microbial community structure can be complex and difficult to assess. We applied nonlinear and generalized linear data analysis methods to relate microbial biomarkers (phospholipids fatty acids, PLFA) to groundwater geochemical characteristics at the Shiprock uranium mill tailings disposal site that is primarily contaminated by uranium, sulfate, and nitrate. First, predictive models were constructed using feedforward artificial neural networks (NN) to predict PLFA classes from geochemistry. To reduce the danger of overfitting, parsimonious NN architectures were selected based on pruning of hidden nodes and elimination of redundant predictor (geochemical) variables. The resulting NN models greatly outperformed the generalized linear models. Sensitivity analysis indicated that tritium, which was indicative of riverine influences, and uranium were important in predicting the distributions of the PLFA classes. In contrast, nitrate concentration and inorganic carbon were least important, and total ionic strength was of intermediate importance. Second, nonlinear principal components (NPC) were extracted from the PLFA data using a variant of the feedforward NN. The NPC grouped the samples according to similar geochemistry. PLFA indicators of Gram-negative bacteria and eukaryotes were associated with the groups of wells with lower levels of contamination. The more contaminated samples contained microbial communities that were predominated by terminally branched saturates and branched monounsaturates that are indicative of metal reducers, actinomycetes, and Gram-positive bacteria. These results indicate that the microbial community at the site is coupled to the geochemistry and knowledge of the geochemistry allows prediction of the community composition

Cold seeps in Monterey Bay, California: Geochemistry of pore waters and relationship to benthic foraminiferal calcite

International Nuclear Information System (INIS)

Gieskes, Joris; Rathburn, Anthony E.; Martin, Jonathan B.; Perez, M. Elena; Mahn, Chris; Bernhard, Joan M.; Day, Shelley

2011-01-01

Highlights: → We describe the geochemistry of pore waters in the Clam Flats area of Monterey Bay. → The geochemical data are compared with the δ 13 C chemistry of benthic foraminifera. → Living foraminifera indicate little effects of pore water low δ 13 C (DIC) in the clam bed. → This phenomenon and its implications are discussed in detail. → Implications with regards to paleo-methane seepage are discussed. - Abstract: An extensive geochemical and biogeochemical examination of CH 4 seeps in the Clam Flats area of Monterey Bay provides insight into the character of relationships between seep geochemistry and benthic foraminiferal geochemistry. The area is characterized by sulfide-rich fluids. Sulfide increases are associated with large increases in alkalinity, as well as small decreases in dissolved Ca and Mg. In addition, only small increases in NH 4 are observed, but values of δ 13 C of dissolved inorganic C are as low as -60 per mille at shallow depths ( 4 , which is transported upward by slow seepage of pore fluids. The geochemistry of the pore fluids should be relevant to the geochemistry of the carbonate tests of living and dead foraminifera. However, a profound disequilibrium of approximately an order of magnitude occurs between the δ 13 C values of stained (cytoplasm-containing) foraminiferal carbonate and the C isotope values of ambient pore water dissolved inorganic C. Reasons are unclear for this isotopic disequilibrium, but have important implications for interpretations of foraminiferal carbonate as a paleoenvironmental proxy. Much fine scale work is needed to fully understand the relationships between the biogeochemistry of benthic foraminifera and the geochemistry of the pore waters where they live.

Geophysical Methods for Investigating Ground-Water Recharge

Science.gov (United States)

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

2007-01-01

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

Stratigraphy, sedimentology and bulk organic geochemistry of black ...

Indian Academy of Sciences (India)

Stratigraphy, sedimentology and bulk organic geochemistry of black shales from the Proterozoic. Vindhyan Supergroup (central India). S Banerjee1,∗. , S Dutta. 2. , S Paikaray. 1 and U Mann. 2. 1. Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India. 2. Forschungszentrum ...

Review of geophysical characterization methods used at the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

GV Last; DG Horton

2000-03-23

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

Solar Wind Monitor--A School Geophysics Project

Science.gov (United States)

Robinson, Ian

2018-01-01

Described is an established geophysics project to construct a solar wind monitor based on a nT resolution fluxgate magnetometer. Low-cost and appropriate from school to university level it incorporates elements of astrophysics, geophysics, electronics, programming, computer networking and signal processing. The system monitors the earth's field in…

Geochemistry and ore prospecting; Geochimie et prospection miniere

Energy Technology Data Exchange (ETDEWEB)

Le Caignec, R. [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1954-07-01

Applied geochemistry is a new technique which helps the geologist in detecting ore deposits. Some deposits, even when they are covered with rather thick surface structures, form around these zones where the infinitesimal content of some elements of soils or waters is notably different. These 'anomalies' may be contemporaneous to the deposit-structure (primary dispersion) or may have occurred later (secondary dispersion). Various factors rule these anomalies: ore-stability, soil homogeneity, water conditions, topography, vegetation, etc... Applied geochemistry is in fact the study of analysis techniques of metal traces in soils as well as the geological interpretation of observed anomalies. This report gives practical data on sampling methods, yields, costs and also on special problems of uranium geochemistry. (author) [French] La geochimie appliquee est une nouvelle technique qui vient aider le geologue dans la detection des gisements de minerais. Certains gisements, meme lorsqu'ils sont recouverts par des formations superficielles relativement epaisses, creent autour d'eux des zones ou la teneur infinitesimale des sols ou des eaux en certains elements varie notablement. Ces ''anomalies'' peuvent etre contemporaines de la formation du gisement (dispersion primaire) ou posterieures a celle-ci (dispersion secondaire). De nombreux facteurs gouvernent ces anomalies: stabilite du minerai, homogeneite du sol, regime des eaux, topographie, vegetation, etc... L'etude des techniques d'analyse des traces de metaux dans les sols et l'interpretation geologique des anomalies obtenues constituent la geochimie appliquee. Ce rapport contient, en outre, des donnees pratiques sur les procedes d'echantillonnage, le rendement, les prix de revient, ainsi que sur quelques problemes particuliers a la geochimie de l'uranium. (auteur)

Geochemistry and ore prospecting; Geochimie et prospection miniere

Energy Technology Data Exchange (ETDEWEB)

Le Caignec, R [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1954-07-01

Applied geochemistry is a new technique which helps the geologist in detecting ore deposits. Some deposits, even when they are covered with rather thick surface structures, form around these zones where the infinitesimal content of some elements of soils or waters is notably different. These 'anomalies' may be contemporaneous to the deposit-structure (primary dispersion) or may have occurred later (secondary dispersion). Various factors rule these anomalies: ore-stability, soil homogeneity, water conditions, topography, vegetation, etc... Applied geochemistry is in fact the study of analysis techniques of metal traces in soils as well as the geological interpretation of observed anomalies. This report gives practical data on sampling methods, yields, costs and also on special problems of uranium geochemistry. (author) [French] La geochimie appliquee est une nouvelle technique qui vient aider le geologue dans la detection des gisements de minerais. Certains gisements, meme lorsqu'ils sont recouverts par des formations superficielles relativement epaisses, creent autour d'eux des zones ou la teneur infinitesimale des sols ou des eaux en certains elements varie notablement. Ces ''anomalies'' peuvent etre contemporaines de la formation du gisement (dispersion primaire) ou posterieures a celle-ci (dispersion secondaire). De nombreux facteurs gouvernent ces anomalies: stabilite du minerai, homogeneite du sol, regime des eaux, topographie, vegetation, etc... L'etude des techniques d'analyse des traces de metaux dans les sols et l'interpretation geologique des anomalies obtenues constituent la geochimie appliquee. Ce rapport contient, en outre, des donnees pratiques sur les procedes d'echantillonnage, le rendement, les prix de revient, ainsi que sur quelques problemes particuliers a la geochimie de l'uranium. (auteur)

Report of the Cerro Chato ultrabasic geophysical studies

International Nuclear Information System (INIS)

Cicalese, H.; Mari, C.; Lema, F.; Valverde, C.; Haut, R.

1987-01-01

This report refers to the obtained results of geophysical practiced during the year 1985 in the area of the ultrabasic of Cerro Chato, located in the area called Puntas del Malbajar in Durazno province. The aim was rehearsed an answer of an ultrabasic behaviour of the geophysical prospecting methods.They were carried out studies in magnetometry, induced polarization, electromagnetism and resistivity measurements in electric vertical sound. As well conclusions as recommendations express that applied geophysical methods allow to make ultrabasic charts or maps.

Application of nuclear-geophysical methods to reserves estimation

International Nuclear Information System (INIS)

Bessonova, T.B.; Karpenko, I.A.

1980-01-01

On the basis of the analysis of reports dealing with calculations of mineral reserves considered are shortcomings in using nuclear-geophysical methods and in assessment of the reliability of geophysical sampling. For increasing efficiency of nuclear-geophysical investigations while prospecting ore deposits, it is advisable to introduce them widely instead of traditional geological sampling methods. For this purpose it is necessary to increase sensitivity and accuracy of radioactivity logging methods, to provide determination of certain elements in ores by these methods

Groundwater geophysics. A tool for hydrology. 2. ed.

Energy Technology Data Exchange (ETDEWEB)

Kirsch, Reinhard (ed.) [Landesamt fuer Natur und Umwelt, Flintbek (Germany). Abt. Geologie/Boden

2009-07-01

Access to clean water is a human right and a basic requirement for economic development. The safest kind of water supply is the use of groundwater. Since groundwater normally has a natural protection against pollution by the covering layers, only minor water treatment is required. Detailed knowledge on the extent, hydraulic properties, and vulnerability of groundwater reservoirs is necessary to enable a sustainable use of the resources. This book addresses students and professionals in Geophysics and Hydrogeology. The aim of the authors is to demonstrate the application of geophysical techniques to provide a database for hydrogeological decisions like drillhole positioning or action plans for groundwater protection. Physical fundamentals and technical aspects of modern geophysical reconnaissance methods are discussed in the first part of the book. Beside 'classical' techniques like seismic, resistivity methods, radar, magnetic, and gravity methods emphasis is on relatively new techniques like complex geoelectric, radiomagnetotellurics, vertical groundwater flow determination, or nuclear magnetic resonance. An overview of direct push techniques is given which can fill the gap between surface and borehole geophysics. The applications of these techniques for hydrogeological purposes are illustrated in the second part of the book. The investigation of pore aquifers is demonstrated by case histories from Denmark, Germany, and Egypt. Examples for the mapping of fracture zone and karst aquifers as well as for saltwater intrusions leading to reduced groundwater quality are shown. The assessment of hydraulic conductivities of aquifers by geophysical techniques is discussed with respect to the use of porosity - hydraulic conductivity relations and to geophysical techniques like NMR or SIP which are sensitive to the effective porosity of the material. The classification of groundwater protective layers for vulnerability maps as required by the EU water framework

Archean and proterozoic in the West-European Hercynian chain: isotopic geochemistry (Sr-Nd-Pb) and U-Pb geochronology on zircons

International Nuclear Information System (INIS)

Guerrot, C.

1989-01-01

The first part of this research thesis reports the study of isotopic (Sr-Nd-Pb) geochemistry and U-Pb geochronology on zircons in the immersed granulites of the Bay of Biscay: U-Pb geochronology on zircons, Nd isotopic geochemistry, Sr isotopic geochemistry, common Pb, Rb-Sr, Sm-Nd and rare earth data on minerals, comparison with other European granulites, comparison with West-Africa, study of Archean and proterozoic in the Hercynian chain. The second part reports the study of the U-Pb geochronology on zircon in the Cadomian, and the third part addresses the Sr-Nd isotopic geochemistry of some Cadomian granitoid, and the crust contamination in different regions [fr

Application of surface geophysics to ground-water investigations

Science.gov (United States)

Zohdy, Adel A.R.; Eaton, Gordon P.; Mabey, Don R.

1974-01-01

This manual reviews the standard methods of surface geophysics applicable to ground-water investigations. It covers electrical methods, seismic and gravity methods, and magnetic methods. The general physical principles underlying each method and its capabilities and limitations are described. Possibilities for non-uniqueness of interpretation of geophysical results are noted. Examples of actual use of the methods are given to illustrate applications and interpretation in selected geohydrologic environments. The objective of the manual is to provide the hydrogeologist with a sufficient understanding of the capabilities, imitations, and relative cost of geophysical methods to make sound decisions as to when to use of these methods is desirable. The manual also provides enough information for the hydrogeologist to work with a geophysicist in designing geophysical surveys that differentiate significant hydrogeologic changes.

Geophysical background and as-built target characteristics

International Nuclear Information System (INIS)

Allen, J.W.

1994-09-01

The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) has provided a facility for DOE, other Government agencies, and the private sector to evaluate and document the utility of specific geophysical measurement techniques for detecting and defining cultural and environmental targets. This facility is the Rabbit Valley Geophysics Performance Evaluation Range (GPER). Geophysical surveys prior to the fiscal year (FY) 1994 construction of new test cells showed the primary test area to be relatively homogeneous and free from natural or man-made artifacts, which would generate spurious responses in performance evaluation data. Construction of nine new cell areas in Rabbit Valley was completed in June 1994 and resulted in the emplacement of approximately 150 discrete targets selected for their physical and electrical properties. These targets and their geophysical environment provide a broad range of performance evaluation parameters from ''very easy to detect'' to ''challenging to the most advanced systems.'' Use of nonintrusive investigative techniques represents a significant improvement over intrusive characterization methods, such as drilling or excavation, because there is no danger of exposing personnel to possible hazardous materials and no risk of releasing or spreading contamination through the characterization activity. Nonintrusive geophysical techniques provide the ability to infer near-surface structure and waste characteristics from measurements of physical properties associated with those targets

Looking Forward to the electronic Geophysical Year

Science.gov (United States)

Kamide, Y.; Baker, D. N.; Thompson, B.; Barton, C.; Kihn, E.

2004-12-01

During the International Geophysical Year (1957-1958), member countries established many new capabilities pursuing the major IGY objectives of collecting geophysical data as widely as possible and providing free access to these data for all scientists around the globe. A key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories. The worldwide scientific community has now endorsed and is promoting an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the 50th anniversary of the IGY in 2007-2008 and would provide a forward impetus to geophysics in the 21st century, similar to that provide by the IGY fifty years ago. The eGY concept advocates the establishment of a series of virtual geophysical observatories now being deployed in cyberspace. We discuss plans to aggregate measurements into a readily accessible database along with analysis, visualization, and display tools that will make information available and useful to the scientific community, to the user community, and to the general public. We are examining the possibilities for near-realtime acquisition of data and utilization of forecast tools in order to provide users with advanced space weather capabilities. This program will provide powerful tools for education and public outreach concerning the connected Sun-Earth System.

Rapid geophysical surveyor

International Nuclear Information System (INIS)

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

1993-01-01

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

Development of Geophysical Ideas and Institutions in Ottoman Empire

Science.gov (United States)

Ozcep, Ferhat; Ozcep, Tazegul

2015-04-01

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

Cold seeps in Monterey Bay, California: Geochemistry of pore waters and relationship to benthic foraminiferal calcite

Energy Technology Data Exchange (ETDEWEB)

Gieskes, Joris, E-mail: jgieskes@ucsd.edu [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States); Rathburn, Anthony E. [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States)] [Indiana State University, Department of Earth and Environmental Systems, Terre Haute, IN 47809 (United States); Martin, Jonathan B. [University of Florida, Department of Geological Sciences, Gainesville, FL 32611-2120 (United States); Perez, M. Elena [Indiana State University, Department of Earth and Environmental Systems, Terre Haute, IN 47809 (United States)] [The Natural History Museum, Department of Palaeontology, Cromwell Road, London SW7 5BD (United Kingdom); Mahn, Chris [Scripps Institution of Oceanography, IOD-0208, 9500 Gilman Drive, La Jolla, CA 92093-0208 (United States); Bernhard, Joan M. [Woods Hole Oceanographic Institution, Geology and Geophysics Department, MS52, Woods Hole, MA 02543 (United States); Day, Shelley [University of Florida, Department of Geological Sciences, Gainesville, FL 32611-2120 (United States)

2011-05-15

Highlights: > We describe the geochemistry of pore waters in the Clam Flats area of Monterey Bay. > The geochemical data are compared with the {delta}{sup 13}C chemistry of benthic foraminifera. > Living foraminifera indicate little effects of pore water low {delta}{sup 13}C (DIC) in the clam bed. > This phenomenon and its implications are discussed in detail. > Implications with regards to paleo-methane seepage are discussed. - Abstract: An extensive geochemical and biogeochemical examination of CH{sub 4} seeps in the Clam Flats area of Monterey Bay provides insight into the character of relationships between seep geochemistry and benthic foraminiferal geochemistry. The area is characterized by sulfide-rich fluids. Sulfide increases are associated with large increases in alkalinity, as well as small decreases in dissolved Ca and Mg. In addition, only small increases in NH{sub 4} are observed, but values of {delta}{sup 13}C of dissolved inorganic C are as low as -60 per mille at shallow depths (<3 cm). These observations indicate that all these processes are related to the bacterial oxidation of CH{sub 4}, which is transported upward by slow seepage of pore fluids. The geochemistry of the pore fluids should be relevant to the geochemistry of the carbonate tests of living and dead foraminifera. However, a profound disequilibrium of approximately an order of magnitude occurs between the {delta}{sup 13}C values of stained (cytoplasm-containing) foraminiferal carbonate and the C isotope values of ambient pore water dissolved inorganic C. Reasons are unclear for this isotopic disequilibrium, but have important implications for interpretations of foraminiferal carbonate as a paleoenvironmental proxy. Much fine scale work is needed to fully understand the relationships between the biogeochemistry of benthic foraminifera and the geochemistry of the pore waters where they live.

Integrated acoustic, mineralogy, and geomechanics characterization of the Huron shale southern West Virginia, USA

Energy Technology Data Exchange (ETDEWEB)

Franquet, J.A.; Mitra, Arijit; Warrington, D.S.; Moos, Daniel; Lacazette, Alfred [Society of Petroleum Engineers (Canada)

2011-07-01

Successful hydraulic fracturing and horizontal drilling are the key to exploiting unconventional shale gas reservoirs. Acoustic anisotropy, in-situ stress, mineralogy and organic matter content are important factors in well completion design. This paper explores an integrated acoustic, mineralogy and geomechanics characterization of the Huron shale, located in south west Virginia, USA. The study consisted of acquiring the borehole acoustic and mineralogy logging data, in addition to conventional logs, from a vertical well prior to hydraulic fracturing and microseismic monitoring. The acoustic data were processed for borehole Stoneley reflective indicators and radial velocity variations. Substantial transverse acoustic anisotropy was noticed and used to acquire vertical and horizontal dynamic elastic properties. A micromechanical constitutive model, arrived at through mineralogy and petrophysical analysis, was used to produce the stress-strain behavior of the rock. This stress profile, with accurate mineralogy and petrophysical analysis, provides important information for best selection of lateral wells and helps in the identification of natural fracture barriers.

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

Directory of Open Access Journals (Sweden)

Maryam Abdi

2012-04-01

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

Impacts of variability in geomechanical properties on hydrate bearing sediment responses

Science.gov (United States)

Lin, J. S.; Uchida, S.; Choi, J. H.; Seol, Y.

2017-12-01

Hydrate bearing sediments (HBS) may become unstable during the gas production operation, or from natural processes such as change in the landform or temperature. The geomechanical modeling is a rational way to assess HBS stability regardless of the process involved. At the present time, such modeling is laced with uncertainties. The uncertainties come from many sources that include the adequacy of a modeling framework to accurately project the response of HBS, the gap in the available field information, and the variability in the laboratory test results from limited samples. For a reasonable stability assessment, the impact of the various uncertainties have to be addressed. This study looks into one particular aspect of the uncertainty, namely, the uncertainty caused by the scatter in the laboratory tests and the ability of a constitutive model to adequately represent them. Specifically this study focuses on the scatter in the results from laboratory tests on high quality pressured core samples from a marine site, and use a critical state constitutive model to represent them. The study investigates how the HBS responses shift when the parameters of the constitutive model are varied to reflect the different aspects of experimental results. Also investigated are impacts on the responses by altering certain formulations of the constitutive model to suit particular sets of results.

Geophysical investigations in Jordan

Science.gov (United States)

Kovach, R.L.; Andreasen, G.E.; Gettings, M.E.; El-Kaysi, K.

1990-01-01

A number of geophysical investigations have been undertaken in the Hashemite Kingdom of Jordan to provide data for understanding the tectonic framework, the pattern of seismicity, earthquake hazards and geothermal resources of the country. Both the historical seismic record and the observed recent seismicity point to the dominance of the Dead Sea Rift as the main locus of seismic activity but significant branching trends and gaps in the seismicity pattern are also seen. A wide variety of focal plane solutions are observed emphasizing the complex pattern of fault activity in the vicinity of the rift zone. Geophysical investigations directed towards the geothermal assessment of the prominent thermal springs of Zerga Ma'in and Zara are not supportive of the presence of a crustal magmatic source. ?? 1990.

Petrology and organic geochemistry of the lower Miocene lacustrine sediments (Most Basin, Eger Graben, Czech Republic)

Czech Academy of Sciences Publication Activity Database

Havelcová, Martina; Sýkorová, Ivana; Mach, K.; Trejtnarová, Hana; Blažek, Jaroslav

2015-01-01

Roč. 139, Special issue (2015), s. 26-39 ISSN 0166-5162 R&D Projects: GA ČR(CZ) GA13-18482S Institutional support: RVO:67985891 Keywords : Most Basin * Miocene * coal facies indices * coal petrology * organic geochemistry Subject RIV: DD - Geochemistry Impact factor: 3.294, year: 2015 http://www.sciencedirect.com/science/article/pii/S0166516214001529#

Petrogenesis of Miocene alkaline volcanic suites from western Bohemia. Whole rock geochemistry and Sr-Nd-Pb isotopic signatures.

Czech Academy of Sciences Publication Activity Database

Ulrych, Jaromír; Krmíček, Lukáš; Tomek, Č.; Lloyd, F. E.; Ladenberger, A.; Ackerman, Lukáš; Balogh, K.

2016-01-01

Roč. 76, č. 1 (2016), s. 77-93 ISSN 0009-2819 Institutional support: RVO:67985831 Keywords : Bohemian Massif * Cenozoic alkaline volcanism * Geochemistry * K-Ar ages * Sr-Nd-Pb isotopes Subject RIV: DD - Geochemistry Impact factor: 1.380, year: 2016

Nagra technical report 14-02, geological basics - Dossier IV - Information on geo-mechanics; SGT Etappe 2: Vorschlag weiter zu untersuchender geologischer Standortgebiete mit zugehörigen Standortarealen für die Oberflächenanlage -- Geologische Grundlagen -- Dossier IV -- Geomechanische Unterlagen

Energy Technology Data Exchange (ETDEWEB)

Marschall, P.; Giger, S.

2014-12-15

This dossier is the fourth of a series of eight reports concerning the safety and technical aspects of locations for the disposal of radioactive wastes in Switzerland. This Dossier IV considers the documentation on geo-mechanical aspects that is available. Rock-stress conditions are looked at as are the methods and instrumentation used to establish them. The results of local analyses are presented and discussed, as are the magnitudes and long-term stability of such stress conditions. The geo-mechanical properties of Opalinus Clay as a host rock for a repository are discussed. Mountain-building models and coupled hydro-mechanical processes are also discussed.

Geophysical fluid dynamics

CERN Document Server

Pedlosky, Joseph

1982-01-01

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

Geophysical fluid dynamics

CERN Document Server

Pedlosky, Joseph

1979-01-01

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

Responsibilities, opportunities and challenges in geophysical exploration

International Nuclear Information System (INIS)

Rytle, R.J.

1982-01-01

Geophysical exploration for engineering purposes is conducted to decrease the risk in encountering site uncertainties in construction of underground facilities. Current responsibilities, opportunities and challenges for those with geophysical expertise are defined. These include: replacing the squiggly line format, developing verification sites for method evaluations, applying knowledge engineering and assuming responsibility for crucial national problems involving rock mechanics expertise

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

Science.gov (United States)

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

2015-06-01

Conservation of representative facets of geophysical diversity may help conserve biological diversity as the climate changes. We conducted a global classification of terrestrial geophysical diversity and analyzed how land protection varies across geophysical diversity types. Geophysical diversity was classified in terms of soil type, elevation, and biogeographic realm and then compared to the global distribution of protected areas in 2012. We found that 300 (45%) of 672 broad geophysical diversity types currently meet the Convention on Biological Diversity's Aichi Target 11 of 17% terrestrial areal protection, which suggested that efforts to implement geophysical diversity conservation have a substantive basis on which to build. However, current protected areas were heavily biased toward high elevation and low fertility soils. We assessed 3 scenarios of protected area expansion and found that protection focused on threatened species, if fully implemented, would also protect an additional 29% of geophysical diversity types, ecoregional-focused protection would protect an additional 24%, and a combined scenario would protect an additional 42%. Future efforts need to specifically target low-elevation sites with productive soils for protection and manage for connectivity among geophysical diversity types. These efforts may be hampered by the sheer number of geophysical diversity facets that the world contains, which makes clear target setting and prioritization an important next step. © 2015 Society for Conservation Biology.

Brief overview of geophysical probing technology

International Nuclear Information System (INIS)

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

1982-01-01

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

Geophysical Signitures From Hydrocarbon Contaminated Aquifers

Science.gov (United States)

Abbas, M.; Jardani, A.

2015-12-01

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

Geophysical monitoring in a hydrocarbon reservoir

Science.gov (United States)

Caffagni, Enrico; Bokelmann, Goetz

2016-04-01

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

Archaeological Geophysics in Israel: Past, Present and Future

Science.gov (United States)

Eppelbaum, L. V.

2009-04-01

., and Eshel, H., 2003. GPR investigations at Qumran, Israel: site of the Dead Sea Scrolls discovery. Proceed. of SPIE Conf., 4758, Santa-Barbara, USA, 125-129. Jol, H.M., Freund, R.A., Darawsha, M., Bauman, P.D., Nahas, S., Reeder, P., Savage, K., and Syon, D., 2008. Nazareth excavations project: A GPR perspective. Proceed. of the Symp. on the Application of Geophysics to Engineering and Environmental Problems, Philadelphia, USA, 1407-1413. Kamai, R. and Hatzor, Y.H., 2007. Numerical analysis of block stone displacements in ancient masonry structures: A new method to estimate historic ground motions. Intern. Jour. for Numerical and Analytical Methods in Geomechanics, 32, 1321-1340. Karcz, I. and Kafri, U., 1978. Evaluation of supposed archaeoseismic damage in Israel. Journal of Archaeological Science, 5, No. 3, 237-253. Karcz, I., Kafri, U., and Meshel, Z., 1977. Archaeological evidence for subrecent seismic activity along the Dead Sea-Jordan Rift. Nature, 269, 234-235. Khesin, B.E., Alexeyev, V.V., and Eppelbaum, L.V., 1996. Interpretation of Geophysical Fields in Complicated Environments. Kluwer Academic Publishers (Springer), Ser.: Modern Approaches in Geophysics, Boston - Dordrecht - London. Korjenkov, A.M. and Mazor, E., 1999. Seismogenic origin of the ancient Avdat ruins, Negev Desert, Israel. Natural Hazards, 18, 193-226. Laukhin, S.S., Ronen, A., Pospelova, G.A., Sharonova, Z.V., Ranov, V.A., Burdukiewicz, J.M., Volgina V.A., and Tsatskin, A., 2001. New data on the geology and geochronology of the Lower Palaeolithic site Bizat Ruhama in the Southern Levant. Paleorient, 27 (1), 69-80. McDermott, F., Grün, R., Stringer C.B., and Hawkesworth, C.J., 1993. Mass-spectrometric U-series dates for Israeli Neanderthal/early modern human sites. Nature, 363, 252-255. Marco, S., 2008. Recognition of earthquake-related damage in archaeological sites: Examples from the Dead Sea fault zone. Tectonophysics, 453, No. 1-4, 122-147. Marco, S., Hartal, M., Hazan, N., Lev, L., and

Characterisation of organic carbon in black shales of the Kachchh ...

Indian Academy of Sciences (India)

46

2Petroleum Geochemistry and Microbiology Group, National Geophysical Research Institute, .... gypsiferous shale of the Naredi Formation of early Eocene age (Biswas 1992). The shale .... This inference also helps us to explain the existence.

Matlab Geochemistry: An open source geochemistry solver based on MRST

Science.gov (United States)

McNeece, C. J.; Raynaud, X.; Nilsen, H.; Hesse, M. A.

2017-12-01

The study of geological systems often requires the solution of complex geochemical relations. To address this need we present an open source geochemical solver based on the Matlab Reservoir Simulation Toolbox (MRST) developed by SINTEF. The implementation supports non-isothermal multicomponent aqueous complexation, surface complexation, ion exchange, and dissolution/precipitation reactions. The suite of tools available in MRST allows for rapid model development, in particular the incorporation of geochemical calculations into transport simulations of multiple phases, complex domain geometry and geomechanics. Different numerical schemes and additional physics can be easily incorporated into the existing tools through the object-oriented framework employed by MRST. The solver leverages the automatic differentiation tools available in MRST to solve arbitrarily complex geochemical systems with any choice of species or element concentration as input. Four mathematical approaches enable the solver to be quite robust: 1) the choice of chemical elements as the basis components makes all entries in the composition matrix positive thus preserving convexity, 2) a log variable transformation is used which transfers the nonlinearity to the convex composition matrix, 3) a priori bounds on variables are calculated from the structure of the problem, constraining Netwon's path and 4) an initial guess is calculated implicitly by sequentially adding model complexity. As a benchmark we compare the model to experimental and semi-analytic solutions of the coupled salinity-acidity transport system. Together with the reservoir simulation capabilities of MRST the solver offers a promising tool for geochemical simulations in reservoir domains for applications in a diversity of fields from enhanced oil recovery to radionuclide storage.

POLLUTION PREVENTION OPPORTUNITY ASSESSMENT - GEOCHEMISTRY LABORATORY AT SANDIA NATIONAL LABORATORIES

Science.gov (United States)

These reports summarize pollution prevention opportunity assessments conducted jointly by EPA and DOE at the Geochemistry Laboratory and the Manufacturing and Fabrication Repair Laboratory at the Department of Energy's Sandia National Laboratories facility in Albuquerque, New Mex...

The geochemistry of banded iron formations in the sukumaland ...

African Journals Online (AJOL)

The geochemistry of banded iron formations in the sukumaland greenstone belt of Geita, northern Tanzania: evidence for mixing of hydrothermal and clastic ... the hydrothermal deposits have been contaminated, by up to 20% by weight, with detrital material having a composition similar to modern deep-sea pelagic clays.

Modeling geophysical complexity: a case for geometric determinism

Directory of Open Access Journals (Sweden)

C. E. Puente

2007-01-01

Full Text Available It has been customary in the last few decades to employ stochastic models to represent complex data sets encountered in geophysics, particularly in hydrology. This article reviews a deterministic geometric procedure to data modeling, one that represents whole data sets as derived distributions of simple multifractal measures via fractal functions. It is shown how such a procedure may lead to faithful holistic representations of existing geophysical data sets that, while complementing existing representations via stochastic methods, may also provide a compact language for geophysical complexity. The implications of these ideas, both scientific and philosophical, are stressed.

Geophysics comes of age in oil sands development

Energy Technology Data Exchange (ETDEWEB)

Bauman, P. [WorleyParsons Komex, Calgary, AB (Canada); Birch, R.; Parker, D.; Andrews, B. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

2008-07-01

This paper discussed geophysical techniques developed for oil sands exploration and production applications in Alberta's oil sands region. Geophysical methods are playing an important role in mine planning, tailings containment, water supply, and land reclamation activities. Geophysics techniques are used to estimate the volume of muskeg that needs to be stripped and stored for future reclamation activities as well as to site muskeg piles and delineate the thickness of clay Clearwater formations overlying Cretaceous oil-bearing sands. 2-D electrical resistivity mapping is used to map river-connected deep bedrock Pleistocene paleovalleys in the region. Geophysical studies are also used to investigate the interiors of dikes and berms as well as to monitor salt migration within tailings piles. Sonic and density logs are used to create synthetic seismograms for mapping the Devonian surface in the region. The new applications included the calculation of bitumen saturation from surface sands and shales; muskeg thickness mapping; and non-intrusive monitoring of leachate plumes. Geophysical techniques included 2-D electrical resistivity imaging; transient electromagnetic (EM) technologies; ground penetrating radar; and high-resolution seismic reflections. Polarization, surface nuclear magnetic resonance and push-probe sensing techniques were also discussed. Techniques were discussed in relation to Alberta's Athabasca oil sands deposits. 4 refs.

The application actualities and prospects of geophysical methods to uranium prospecting

International Nuclear Information System (INIS)

Liu Qingcheng

2010-01-01

Basic principles of geophysical methods to uranium prospect are briefly introduced, and the effects as well as problems in using those methods are analysed respectively. Combining with the increasing demand of uranium resources for Chinese nuclear power development and the higher requirements of geophysical techniques, the developing directions and the thoughts of geophysical techniques in uranium prospecting were proposed. A new pattern with producing, teaching and researching together is brought forward to develop advancing uranium prospecting key technologies and to break through technological bottlenecks depending on independent innovation. Integrated geophysical methods for prospecting uranium deposits are suggested. The method includes geophysical techniques as follows: gravity, magnetic, seismic, radioactive, remote sensing, and geochemical method in some proving grounds. Based on the experimental research, new uranium deposits prospecting models with efficient integrated geophysical methods can be established. (authors)

Geomechanical characterization of the Montney Shale northwest Alberta and northeast British Columbia, Canada

Science.gov (United States)

Davey, Heather

Unconventional reservoirs require hydraulic stimulation to be commercially productive. Recently, distinctions have been made between reservoir quality vs. completion quality (Cipolla et al. 2012), emphasizing the importance of both elements for production. There are many sources of variability in reservoir quality; in this thesis I examine several fundamental reservoir properties in detail and combine them in a new way: the Rock Quality Index (RQI). Through the definition of a geomechanical model and corresponding mechanical stratigraphy, those factors having a substantial effect on reservoir quality became apparent. Two fundamental categories; compositional variation and fabric variation, are used to characterize overall reservoir variation. Burial, compaction, hydrocarbon generation, diagenesis, and tectonics all affect the mechanical character and in-situ stress state of the reservoir. The Rock Quality Index (RQI) is an effort to understand how composition and fabric relate to stress anisotropy, fracturing, and rock properties, and ultimately aid in defining the best zones for exploitation. Therefore, this Rock Quality Index (RQI) is vital for the defining the second element of unconventional reservoir success; completion quality. Without a reservoir framework to drive the completion design, high completion quality will be harder to achieve. The original mechanical stratigraphy definition is in turn used as a framework for relating Rock Quality Index (RQI) variations to the factors which caused them. The comparison between Rock Quality Index (RQI) and mechanical stratigraphy shows that zones traditionally thought of as desirable for hydraulic completion (brittle) are also zones of high internal heterogeneity. Formation heterogeneity may be detrimental to hydraulic fracture growth. Using several other data types (multicomponent time-lapse seismic, microseismic, and reservoir engineering tests) in conjunction with the Rock Quality Index (RQI), it is observed that

Geochemistry and distribution of sediments in the East Indian shelf ...

Indian Academy of Sciences (India)

29

trace element geochemistry yielded interesting results about the sediment .... sediments and the core samples are as given in Table 1. ..... radioactive lead, thorium and uranium showed higher concentration in C3 than in C1 ...... Plant Soil, 267,.

Geochemistry and geochronology of the mafic dikes in the Taipusi ...

Indian Academy of Sciences (India)

25

several large linear faults as dividing lines (Fig. 1b; Jahn ... activity between Bainaimiao city and Chifeng city (Stampfli and Borel, 2002). The formation ... In addition, previous studies in the area paid more attention to the geochemistry and.

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

Science.gov (United States)

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

2014-12-01

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

Basic elements of nuclear geophysics

International Nuclear Information System (INIS)

Nordemann, D.J.R.; Pereira, E.B.

1984-01-01

Nuclear Geophysics applies the nuclear radiation detection methodology to the geosciences, specially to study the dynamical processes of the lithosphere, the hydrosphere and the atmosphere as well as some aspects of planetology and astrophysics. Here the main methods are described: alpha-ray and gamma-ray spectrometry, the interaction of alpha and gamma radiation with matter and the detectors used (grid chambers, surface barrier silicon detector for alpha radiation; and sodium iodide thallium activated phosphors, hyperpure and lithium drifted germanium semiconductor detectors for gamma radiation). The principal applications of Nuclear Geophysics are given as examples to ilustrate the use of the methods described. (AUthor) [pt

Effect of Pore Pressure on Slip Failure of an Impermeable Fault: A Coupled Micro Hydro-Geomechanical Model

Science.gov (United States)

Yang, Z.; Juanes, R.

2015-12-01

The geomechanical processes associated with subsurface fluid injection/extraction is of central importance for many industrial operations related to energy and water resources. However, the mechanisms controlling the stability and slip motion of a preexisting geologic fault remain poorly understood and are critical for the assessment of seismic risk. In this work, we develop a coupled hydro-geomechanical model to investigate the effect of fluid injection induced pressure perturbation on the slip behavior of a sealing fault. The model couples single-phase flow in the pores and mechanics of the solid phase. Granular packs (see example in Fig. 1a) are numerically generated where the grains can be either bonded or not, depending on the degree of cementation. A pore network is extracted for each granular pack with pore body volumes and pore throat conductivities calculated rigorously based on geometry of the local pore space. The pore fluid pressure is solved via an explicit scheme, taking into account the effect of deformation of the solid matrix. The mechanics part of the model is solved using the discrete element method (DEM). We first test the validity of the model with regard to the classical one-dimensional consolidation problem where an analytical solution exists. We then demonstrate the ability of the coupled model to reproduce rock deformation behavior measured in triaxial laboratory tests under the influence of pore pressure. We proceed to study the fault stability in presence of a pressure discontinuity across the impermeable fault which is implemented as a plane with its intersected pore throats being deactivated and thus obstructing fluid flow (Fig. 1b, c). We focus on the onset of shear failure along preexisting faults. We discuss the fault stability criterion in light of the numerical results obtained from the DEM simulations coupled with pore fluid flow. The implication on how should faults be treated in a large-scale continuum model is also presented.

Strontium isotopic geochemistry of intrusive rocks, Puerto Rico, Greater Antilles

International Nuclear Information System (INIS)

Jones, L.M.; Kesler, S.E.

1980-01-01

The strontium isotope geochemistry is given for three Puerto Rican intrusive rocks: the granodioritic Morovis and San Lorenzo plutons and the Rio Blanco stock of quartz dioritic composition. The average calculated initial 87 Sr/ 86 Sr ratios are 0.70370, 0.70355 and 0.70408, respectively. In addition, the San Lorenzo data establish a whole-rock isochron of 71 +- 2 m.y., which agrees with the previously reported K-Ar age of 73 m.y. Similarity of most of the intrusive rocks in the Greater Antilles with respect to their strontium isotopic geochemistry regardless of their major element composition indicates that intrusive magmas with a wide range of composition can be derived from a single source material. The most likely source material, in view of the available isotopic data, is the mantle wedge overlying the subduction zone. (orig.)

The geology and geophysics of the Oslo rift

Science.gov (United States)

Ruder, M. E.

1981-01-01

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

Geophysical characterisation of the groundwater-surface water interface

Science.gov (United States)

McLachlan, P. J.; Chambers, J. E.; Uhlemann, S. S.; Binley, A.

2017-11-01

Interactions between groundwater (GW) and surface water (SW) have important implications for water quantity, water quality, and ecological health. The subsurface region proximal to SW bodies, the GW-SW interface, is crucial as it actively regulates the transfer of nutrients, contaminants, and water between GW systems and SW environments. However, geological, hydrological, and biogeochemical heterogeneity in the GW-SW interface makes it difficult to characterise with direct observations. Over the past two decades geophysics has been increasingly used to characterise spatial and temporal variability throughout the GW-SW interface. Geophysics is a powerful tool in evaluating structural heterogeneity, revealing zones of GW discharge, and monitoring hydrological processes. Geophysics should be used alongside traditional hydrological and biogeochemical methods to provide additional information about the subsurface. Further integration of commonly used geophysical techniques, and adoption of emerging techniques, has the potential to improve understanding of the properties and processes of the GW-SW interface, and ultimately the implications for water quality and environmental health.

Site characterization and validation - geophysical single hole logging

International Nuclear Information System (INIS)

Andersson, Per

1989-05-01

A total of 15 boreholes have been drilled for preliminary characterization of a previously unexplored site at the 360 and 385 m level in the Stripa mine. To adequately described the rock mass in the vicinity of these boreholes, a comprehensive program utilizing a large number of geophysical borehole methods has been carried out in 10 of these boreholes. The specific geophysical character of the rock mass and the major deformed units distinguished in the vicinity of the boreholes are recognized, and in certain cases also correlated between the boreholes. A general conclusion based on the geophysical logging results, made in this report, is that the preliminary predictions made in stage 2, of the site characterization and validation project (Olsson et.al, 1988), are adequate. The results from the geophysical logging can support the four predicted fracture/ fracture zones GHa, GHb, GA and GB whereas the predicted zones GC and GI are hard to confirm from the logging results. (author)

Geophysical investigations in the Syyry area, Finland

International Nuclear Information System (INIS)

Heikkinen, E.; Kurimo, M.

1992-12-01

Investigations were carried out at the Syyry site at Sievi using geological, geophysical, geohydrological and geochemical methods in 1987-1991 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

Geophysical investigations in the Olkiluoto area, Finland

International Nuclear Information System (INIS)

Heikkinen, E.; Paananen, M.

1992-12-01

Investigations were carried out at the Olkiluoto site at Eurajoki using geological, geophysical, geohydrological and geochemical methods in 1987-1992 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

Geophysical investigations in the Kivetty area, Finland

International Nuclear Information System (INIS)

Heikkinen, E.; Paananen, M.; Oehberg, A.; Front, K.; Okko, O.; Pitkaenen, P.

1992-09-01

Investigations were carried out at Kivetty site in Konginkangas, in central Finland, by geological, geophysical, geohydrological and geochemical methods in 1987-1991 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. Airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

Geochemistry of subduction zone serpentinites: A review

Science.gov (United States)

Deschamps, Fabien; Godard, Marguerite; Guillot, Stéphane; Hattori, Kéiko

2013-09-01

Over the last decades, numerous studies have emphasized the role of serpentinites in the subduction zone geodynamics. Their presence and role in subduction environments are recognized through geophysical, geochemical and field observations of modern and ancient subduction zones and large amounts of geochemical database of serpentinites have been created. Here, we present a review of the geochemistry of serpentinites, based on the compilation of ~ 900 geochemical data of abyssal, mantle wedge and exhumed serpentinites after subduction. The aim was to better understand the geochemical evolution of these rocks during their subduction as well as their impact in the global geochemical cycle. When studying serpentinites, it is essential to determine their protoliths and their geological history before serpentinization. The geochemical data of serpentinites shows little mobility of compatible and rare earth elements (REE) at the scale of hand-specimen during their serpentinization. Thus, REE abundance can be used to identify the protolith for serpentinites, as well as magmatic processes such as melt/rock interactions before serpentinization. In the case of subducted serpentinites, the interpretation of trace element data is difficult due to the enrichments of light REE, independent of the nature of the protolith. We propose that enrichments are probably not related to serpentinization itself, but mostly due to (sedimentary-derived) fluid/rock interactions within the subduction channel after the serpentinization. It is also possible that the enrichment reflects the geochemical signature of the mantle protolith itself which could derive from the less refractory continental lithosphere exhumed at the ocean-continent transition. Additionally, during the last ten years, numerous analyses have been carried out, notably using in situ approaches, to better constrain the behavior of fluid-mobile elements (FME; e.g. B, Li, Cl, As, Sb, U, Th, Sr) incorporated in serpentine phases

Moving Beyond IGY: An Electronic Geophysical Year (eGY) Concept

Science.gov (United States)

Baker, D. N.; Barton, C. E.; Rodger, A. S.; Thompson, B. J.; Fraser, B.; Papitashvili, V.

2003-12-01

During the International Geophysical Year (1957-1958), member countries established many new geophysical observatories pursuing the major IGY objectives - to collect geophysical data as widely as possible and to provide free access to these data for all scientists around the globe. Today, geophysics has attained a rather good understanding within traditional regions, i.e., the atmosphere, ionosphere, magnetosphere, and other such geospheres. At the same time, it has become clear that much of the new and important science is coming from the studies of interfaces and coupling between geospheres. Thus, if geophysical data are made `'transparently'' available to a much wider range of scientists and students than to those who do the observations, then new and exciting discoveries can be expected. An International Association of Geomagnetic and Aeronomy (IAGA) task force, recognizing that a key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories, proposes that for the 50th anniversary of IGY, the worldwide scientific community should endorse and promote an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the IGY in 2007-2008 and provide a forward impetus to geophysics in 21st century, similar to that provided by the IGY fifty years ago. The IAGA task force strongly advocates: (1) Securing permission and release of existing data; (2) Creating access to information; and (3) Conversion of relevant analog data to digital form. The eGY concept embraces all available and upcoming geophysical data (e.g., atmospheric, ionospheric, geomagnetic, gravity, etc.) through the establishment of a series of virtual geophysical observatories now being `'deployed'' in cyberspace. The eGY concept is modern, global, and timely; it is attractive, pragmatic, and affordable. The eGY is based on the existing and continually developing computing/networking technologies (e.g., XML, Semantic Web

Notes on the history of geophysics in the Ottoman Empire

Science.gov (United States)

Ozcep, F.; Ozcep, T.

2014-09-01

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

Geocongress 84: 20. Geological congress of the Geological Society of South Africa. Abstracts: Pt. 1. General

International Nuclear Information System (INIS)

1984-01-01

Various aspects of the geology, geochemistry and geophysics of the geologic deposits in South Africa are dealt with. Uranium and thorium resources are included in this. There are also chapters on stratigraphy, petrology and petrochemistry

Characterizing fractured rock for fluid-flow, geomechanical, and paleostress modeling: Methods and preliminary results from Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Barton, C.C.; Larsen, E.; Page, W.R.; Howard, T.M.

1993-01-01

Fractures have been characterized for fluid-flow, geomechanical, and paleostress modeling at three localities in the vicinity of drill hole USW G-4 at Yucca Mountain in southwestern Nevada. A method for fracture characterization is introduced that integrates mapping fracture-trace networks and quantifying eight fracture parameters: trace length, orientation, connectivity, aperture, roughness, shear offset, trace-length density, and mineralization. A complex network of fractures was exposed on three 214- to 260-m 2 pavements cleared of debris in the upper lithophysal unit of the Tiva Canyon Member of the Miocene Paint-brush Tuff. The pavements are two-dimensional sections through the three-dimensional network of strata-bound fractures. All fractures with trace lengths greater than 0.2 m were mapped and studied

Stable isotope geochemistry : definitions, terminology, measurement and some applications

International Nuclear Information System (INIS)

Faure, K.

2004-01-01

Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: thermometry, tracers, reaction mechanisms and chemostratigraphy. 52 refs., 11 figs., 2 tabs

Effects of loadingeunloading and wettingedrying cycles on geomechanical behaviors of mudrocks in the Colombian Andes

Institute of Scientific and Technical Information of China (English)

Mario Camilo Torres-Suarez; Adolfo Alarcon-Guzman; Rafael Berdugo-De Moya

2014-01-01

The mudrocks in the Colombian Andes, particularly those exhibiting low cementation (bonding), are susceptible to degradation when the environmental conditions change, which are challenging issues for engineering works. In this paper, the changes in physico-mechanical properties of mudrocks were moni-tored in laboratory, and some influential factors on the mechanical competence of geomaterials were studied. The geotechnical characteristics and experimental designs were developed from physical, chem-ical, mechanical and compositional points of view. In the tests, the techniques such as vapor equilibrium technique (VET) were employed to apply wettingedrying cycles and to control relative humidity (suction-controlled) and loadingeunloading cycles through ultrasonic wave velocities technique. The results show that the main failure mechanisms for the laminated mudrocks start on the microscopic scale by fissures coalescence, exhibiting physico-chemical degradation as well;the global geomechanical behavior presents a state between a ductile, like rock, and a fragile, like soil. The obtained results can provide engineering values according to monitoring laboratory set, when compared with in situ conditions.

Geophysical characterization from Itu intrusive suite

International Nuclear Information System (INIS)

Pascholati, M.E.

1989-01-01

The integrated use of geophysical, geological, geochemical, petrographical and remote sensing data resulted in a substantial increase in the knowledge of the Itu Intrusive Suite. The main geophysical method was gamma-ray spectrometry together with fluorimetry and autoradiography. Three methods were used for calculation of laboratory gamma-ray spectrometry data. For U, the regression method was the best one. For K and Th, equations system and absolute calibration presented the best results. Surface gamma-ray spectrometry allowed comparison with laboratory data and permitted important contribution to the study of environmental radiation. (author)

Geochemistry of rare earths in main media of clay formation and sedimentation

International Nuclear Information System (INIS)

Bonnot-Courtois, C.

1981-01-01

This work aims i) at a better knowledge of rare earth behavior in surface conditions and ii) possible use of rare earth as a marker for argilaceous mineral genesis. Chemical properties of rare earths and geochemistry of these elements in main rocks are recalled. Rare earth behaviour during continental alteration process, experimental hydrolysis of various magmatic materials and rare earth geochemistry in argilaceous minerals in continental shelf are examined. Then some aspects of rare earth behaviour in oceans are studied: alteration of sea bed and hydrothermalism rare earth distribution in pelagic sediments red clays of deep seas and manganese nodules. In conclusion rare earth behaviour in sedimentary processes of the exogenous cycle is summarized [fr

Geophysical surveys and velocimetric measures in the Cerreto di Spoleto (Perugia) area, aiming at a seismic microzoning; Indagini geofisiche e misure velocimetriche finalizzate alla microzonazione sismica dell'area di Cerreto di Spoleto (Perugia)

Energy Technology Data Exchange (ETDEWEB)

Bongiovanni, G.; Martino, S.; Paciello, A.; Verrubbi, V. [ENEA, Div. Caratterizzazione dell' Ambiente e del Territorio, Centro Ricerche Csaccia, S. Maria di Galeria, Rome (Italy)

2001-07-01

Geophysical prospectings and velocimetric measures, aiming at the seismic microzoning of Cerreto di Spoleto area, are presented. Starting from the data obtained by previous geological-geomechanical surveys, seismic-refraction prospectings were carried on in order to obtain a dynamic characterisation and a geometrical description both of soil and rock materials. The velocimetric measures were performed by temporary free-field arrays, recording both environmental noise and small-magnitude seismic events. The analysis of the obtained records is still in progress, in order to evaluate the local seismic wave amplification. [Italian] Vengono illustrate le indagini geofisiche e le misure velocimetriche condotte nell'area di Cerreto di Spoleto (PG) per la microzonazione sismica. In particolare, sulla base dei dati geologici e geomeccanici precedentemente acquisiti, sono state effettuate indagini di sismica a rifrazione che hanno portato alla caratterizzazione dinamica dei litotipi ed alla definizione delle loro geometrie. Le misure velometriche sono state condotte installando array temporanei in free-field per la registrazione di rumore ambientale ed eventi sismici di piccola magnitudo. E' in corso l'elaborazione delle registrazioni ottenute, finalizzata all'analisi degli effetti di amplificazione sismica locale.

A portable marine geophysical data access and management system

Digital Repository Service at National Institute of Oceanography (India)

Kunte, P.D.; Narvekar, P.

Geophysical Oracle Database Management System (GPODMS) that is residing on UNIX True 64 Compaq Alpha server. GPODMS is a stable Oracle database system for longterm storage and systematic management of geophysical data and information of various disciplines...

Rožňava ore field - geophysical works

Directory of Open Access Journals (Sweden)

Géczy Július

1998-12-01

Full Text Available The article prowides a review of geophysical works in the ore field Rožňava conducted up to date. Magnetometric and geoelectric methods and gravimetric measurements have been used. Geophysical works were focused to the solving regional problems whose contribution to the prospecting of vein deposits is not essential.

Geology, water-quality, hydrology, and geomechanics of the Cuyama Valley groundwater basin, California, 2008--12

Science.gov (United States)

Everett, Rhett; Gibbs, Dennis R.; Hanson, Randall T.; Sweetkind, Donald S.; Brandt, Justin T.; Falk, Sarah E.; Harich, Christopher R.

2013-01-01

To assess the water resources of the Cuyama Valley groundwater basin in Santa Barbara County, California, a series of cooperative studies were undertaken by the U.S. Geological Survey and the Santa Barbara County Water Agency. Between 2008 and 2012, geologic, water-quality, hydrologic and geomechanical data were collected from selected sites throughout the Cuyama Valley groundwater basin. Geologic data were collected from three multiple-well groundwater monitoring sites and included lithologic descriptions of the drill cuttings, borehole geophysical logs, temperature logs, as well as bulk density and sonic velocity measurements of whole-core samples. Generalized lithologic characterization from the monitoring sites indicated the water-bearing units in the subsurface consist of unconsolidated to partly consolidated sand, gravel, silt, clay, and occasional cobbles within alluvial fan and stream deposits. Analysis of geophysical logs indicated alternating layers of finer- and coarser-grained material that range from less than 1 foot to more than 20 feet thick. On the basis of the geologic data collected, the principal water-bearing units beneath the monitoring-well sites were found to be composed of younger alluvium of Holocene age, older alluvium of Pleistocene age, and the Tertiary-Quaternary Morales Formation. At all three sites, the contact between the recent fill and younger alluvium is approximately 20 feet below land surface. Water-quality samples were collected from 12 monitoring wells, 27 domestic and supply wells, 2 springs, and 4 surface-water sites and were analyzed for a variety of constituents that differed by site, but, in general, included trace elements; nutrients; dissolved organic carbon; major and minor ions; silica; total dissolved solids; alkalinity; total arsenic and iron; arsenic, chromium, and iron species; and isotopic tracers, including the stable isotopes of hydrogen and oxygen, activities of tritium, and carbon-14 abundance. Of the 39

Geophysical investigations at ORNL solid waste storage area 3

International Nuclear Information System (INIS)

Rothschild, E.R.; Switek, J.; Llopis, J.L.; Farmer, C.D.

1985-07-01

Geophysical investigations at ORNL solid waste storage area 3 have been carried out. The investigations included very-low-frequency-electromagnetic resistivity (VLF-EM), electrical resistivity, and seismic refraction surveys. The surveys resulted in the measurement of basic geophysical rock properties, as well as information on the depth of weathering and the configuration of the bedrock surface beneath the study area. Survey results also indicate that a number of geophysical anomalies occur in the shallow subsurface at the site. In particular, a linear feature running across the geologic strike in the western half of the waste disposal facility has been identified. This feature may conduct water in the subsurface. The geophysical investigations are part of an ongoing effort to characterize the site's hydrogeology, and the data presented will be valuable in directing future drilling and investigations at the site. 10 refs., 6 figs

Geomechanical Simulation of CO₂ Leakage and Cap Rock Remediation

Energy Technology Data Exchange (ETDEWEB)

Nygaard, Runar [Univ. of Missouri, Rolla, MO (United States); Bai, Baojun [Univ. of Missouri, Rolla, MO (United States); Eckert, Andreas [Univ. of Missouri, Rolla, MO (United States)

2012-09-30

CO₂ sequestration into porous and permeable brine filled aquifers is seen as one of the most likely near-term solutions for reducing greenhouse gases. Safely storing injected CO₂, which is less dense than water, requires trapping the CO₂ under an impermeable rock which would act as a seal. One of the concerns with CO₂ sequestration is the generation of new fractures or reactivation of existing fractures and faults caused by CO₂ injection into the sealing formation. Mitigation strategies must be developed to remediate potentially leaking faults or fractures. This project evaluated potential storage scenarios in the state of Missouri and developed coupled reservoir and geomechanic simulations to identify storage potential and leakage risks. Further, several injectable materials used to seal discontinuities were evaluated under subsurface conditions. The four sealant materials investigated were paraffin wax, silica based gel, polymer based gel, and micro-cement, which all significantly reduced the fracture permeability. However, the micro-cement was the most effective sealing agent and the only sealant able to withstand the large differential pressure caused by CO₂ or brine injection and create a strong seal to prevent further fracturing.

Japan-U. S. seminar on magmatic contributions to hydrothermal systems

Energy Technology Data Exchange (ETDEWEB)

Muffler, L. (U. S. Geological Survey, CA (United States)); Hedenquist, J. (Geological Survey of Japan, Tsukuba (Japan)); Kesler, S. (University of Michigan, MI (United States)); Izawa, E. (Kyushu University, Fukuoka (Japan). Faculty of Engineering)

1992-08-31

A multidisciplinary Seminar on Magmatic Contributions to Hydrothermal Systems'' was held at Ebino and Kagoshima at Kyushu, November, 1991. The principal purpose of the Ebino/Kagoshima Seminar was to bring together a small group of individuals which have been conducting active research on magmatic contributions to hydrothermal systems. The Seminar focussed on the porphyry and epithermal ore environments because of the potential to relate these environments to active volcanic and geothermal systems. Disciplines included valcanology, volcanic gas geochemistry, water geochemistry, isotope geochemistry, geochemical modeling, experimental geochemistry, igneous petrology, geothermal geology, economic geology, fluid-inclusion study, geophysics, and physical modeling. This paper summarizes the outline and significance of the Seminar. It was pointed out that understanding magmatic contributions to hydrothermal systems would require augmented experimental investigations, numerical modeling, field studies, and drilling.

uranium and thorium exploration by geophysical methods

International Nuclear Information System (INIS)

Yueksel, F.A.; Kanli, A.I.

1997-01-01

Radioactivity is often measured from the ground in mineral exploration. If large areas have to be investigated, it is often unsuitable to carry out the measurements with ground-bound expeditions. A geophysical method of gamma-ray spectrometry is generally applied for uranium exploration. Exploration of uranium surveys were stopped after the year of 1990 in Turkey. Therefore the real potential of uranium in Turkey have to be investigated by using the geophysical techniques

Site characterization at the Rabbit Valley Geophysical Performance Evaluation Range

International Nuclear Information System (INIS)

Koppenjan, S.; Martinez, M.

1994-01-01

The United States Department of Energy (US DOE) is developing a Geophysical Performance Evaluation Range (GPER) at Rabbit Valley located 30 miles west of Grand Junction, Colorado. The purpose of the range is to provide a test area for geophysical instruments and survey procedures. Assessment of equipment accuracy and resolution is accomplished through the use of static and dynamic physical models. These models include targets with fixed configurations and targets that can be re-configured to simulate specific specifications. Initial testing (1991) combined with the current tests at the Rabbit Valley GPER will establish baseline data and will provide performance criteria for the development of geophysical technologies and techniques. The US DOE's Special Technologies Laboratory (STL) staff has conducted a Ground Penetrating Radar (GPR) survey of the site with its stepped FM-CW GPR. Additionally, STL contracted several other geophysical tests. These include an airborne GPR survey incorporating a ''chirped'' FM-CW GPR system and a magnetic survey with a surfaced-towed magnetometer array unit Ground-based and aerial video and still frame pictures were also acquired. STL compiled and analyzed all of the geophysical maps and created a site characterization database. This paper discusses the results of the multi-sensor geophysical studies performed at Rabbit Valley and the future plans for the site

Stable isotope geochemistry. 3. rev. and enl. ed.

International Nuclear Information System (INIS)

Hoefs, J.

1987-01-01

Stable Isotope Geochemistry is an authoritative book comprising theoretical and experimental principles; surveying important fractionation mechanisms affecting the most important elements; discussing the natural variations of geologically important reservoirs. This updated 3rd edition, with a completely rewritten and extended main part, contains two new chapters on stable isotope composition of mantle material and on changes of the ocean during the geological past. (orig.)

Comparison study of selected geophysical and geotechnical parameters

DEFF Research Database (Denmark)

Nissen, Randi Warncke; Poulsen, Søren Erbs

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

Testing how geophysics can reduce the uncertainty of groundwater model predictions

DEFF Research Database (Denmark)

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

2014-01-01

Geophysical data are increasingly used to construct groundwater models. Such data are collected at lower cost and much higher density than the traditionally used geological, hydraulic, and hydrological data. The geophysical data are often inverted independently and used together with geological......, respectively. There is also complete flexibility in the choice of relationships between hydraulic and geophysical properties. Noise can be added to the synthetic hydrologic and geophysical datasets and these exhaustive data sets can be down sampled to represent realistic data sets of varying measurement...... with and covered by layered glaciofluvial and glacial deposits. The hydrological data consist of 35 hydraulic head measurements and one river discharge measurement, while the geophysical data consist of 77 TEM soundings. The data are inverted sequentially and jointly. Through this example, we highlight the value...

Description of geophysical data in the SKB database GEOTAB. Version 2

International Nuclear Information System (INIS)

Sehlstedt, S.

1991-01-01

For the storage of different types of data collected by SKB a database called GEOTAB has been created. The following data is stored in the database: Background data, geological data, geophysical data, hydrogeological and meteorological data, hydrochemical data, and tracer tests. This report describes the data flow for different types of geophysical measurement. The descriptions start with measurement and end with the storage of data in GEOTAB. Each process and the resulting data volume is presented separately. The geophysical measurements have been divided into the following subjects: Geophysical ground surface measurements, geophysical borehole logging, and petrophysical measurements. Each group of measurements is described in an individual chapter. In each chapter several measuring techniques are described and each method has a data table and a flyleaf table in GEOTAB. (author)

Calcium stable isotope geochemistry

Energy Technology Data Exchange (ETDEWEB)

Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

2016-08-01

This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

Calcium stable isotope geochemistry

International Nuclear Information System (INIS)

Gausonne, Nikolaus; Schmitt, Anne-Desiree; Heuser, Alexander; Wombacher, Frank; Dietzel, Martin; Tipper, Edward; Schiller, Martin

2016-01-01

This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

Technical Note: Calibration and validation of geophysical observation models

NARCIS (Netherlands)

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

2012-01-01

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

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

Science.gov (United States)

Eppelbaum, Lev

2015-04-01

. of the 2011 SAGEEP Conference, Charleston, South Carolina, USA, 24, 24-60. Eppelbaum, L.V., Khesin, B.E. and Itkis, S.E., 2001. Prompt magnetic investigations of archaeological remains in areas of infrastructure development: Israeli experience. Archaeological Prospection, 8, No.3, 163-185. Eppelbaum, L.V., Khesin, B.E. and Itkis, S.E., 2010. Archaeological geophysics in arid environments: Examples from Israel. Journal of Arid Environments, 74, No. 7, 849-860. Eppelbaum, L.V., Zheludev, V. and Averbuch, A., 2014. Diffusion maps as a powerful tool for integrated geophysical field analysis to detecting hidden karst terranes. Izv. Acad. Sci. Azerb. Rep., Ser.: Earth Sciences, No. 1-2, 36-46. Hadamard, J., 1902. Sur les problèmes aux dérivées partielles et leur signification physique. Princeton University Bulletin, 13, 49-52. Khesin, B.E. and Eppelbaum, L.V., 1997. The number of geophysical methods required for target classification: quantitative estimation. Geoinformatics, 8, No.1, 31-39. Zhdanov, M.S., 2002. Geophysical Inverse Theory and Regularization Problems. Methods in Geochemistry and Geophysics, Vol. 36. Elsevier, Amsterdam.

MLS/Aura Level 2 Diagnostics, Geophysical Parameter Grid V004

Data.gov (United States)

National Aeronautics and Space Administration — ML2DGG is the EOS Aura Microwave Limb Sounder (MLS) product containing geophysical diagnostic quantities pertaining directly to the standard geophysical data...

Geomechanical Model Calibration Using Field Measurements for a Petroleum Reserve

Science.gov (United States)

Park, Byoung Yoon; Sobolik, Steven R.; Herrick, Courtney G.

2018-03-01

A finite element numerical analysis model has been constructed that consists of a mesh that effectively captures the geometries of Bayou Choctaw (BC) Strategic Petroleum Reserve (SPR) site and multimechanism deformation (M-D) salt constitutive model using the daily data of actual wellhead pressure and oil-brine interface location. The salt creep rate is not uniform in the salt dome, and the creep test data for BC salt are limited. Therefore, the model calibration is necessary to simulate the geomechanical behavior of the salt dome. The cavern volumetric closures of SPR caverns calculated from CAVEMAN are used as the field baseline measurement. The structure factor, A 2, and transient strain limit factor, K 0, in the M-D constitutive model are used for the calibration. The value of A 2, obtained experimentally from BC salt, and the value of K 0, obtained from Waste Isolation Pilot Plant salt, are used for the baseline values. To adjust the magnitude of A 2 and K 0, multiplication factors A 2 F and K 0 F are defined, respectively. The A 2 F and K 0 F values of the salt dome and salt drawdown skins surrounding each SPR cavern have been determined through a number of back analyses. The cavern volumetric closures calculated from this model correspond to the predictions from CAVEMAN for six SPR caverns. Therefore, this model is able to predict behaviors of the salt dome, caverns, caprock, and interbed layers. The geotechnical concerns associated with the BC site from this analysis will be explained in a follow-up paper.

Integrated geophysical-geochemical methods for archaeological prospecting

OpenAIRE

Persson, Kjell

2005-01-01

A great number of field measurements with different methods and instruments were conducted in attempts to develop a method for an optimal combination of various geochemical and geophysical methods in archaeological prospecting. The research presented in this thesis focuses on a study of how different anthropogenic changes in the ground can be detected by geochemical and geophysical mapping and how the results can be presented. A six-year pilot project, Svealand in Vendel and Viking periods (S...

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

Directory of Open Access Journals (Sweden)

Fenglin Peng

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-11-01

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

Reactive Transport Models with Geomechanics to Mitigate Risks of CO2 Utilization and Storage

Energy Technology Data Exchange (ETDEWEB)

Deo, Milind [Univ. of Utah, Salt Lake City, UT (United States); Huang, Hai [Univ. of Utah, Salt Lake City, UT (United States); Kweon, Hyukmin [Univ. of Utah, Salt Lake City, UT (United States); Guo, Luanjing [Univ. of Utah, Salt Lake City, UT (United States)

2016-03-28

revealed that an initial high-permeability pathway facilitated the formation of wormholes. The peak cation concentrations and general trends were matched using Toughreact. Batch reactor modeling showed that the geometric factors obtained using powder data that related effective surface area to the BET surface area had to be reduced for fractured samples and cores. This indicates that the available surface area in consolidated samples is lower than that deduced from powder experiments. Field-scale modeling of reactive transport and geomechanics was developed in parallel at Idaho National Laboratory. The model is able to take into account complex chemistry, and consider interactions of natural fractures and faults. Poroelastic geomechanical considerations are also included in the model.

An Integral, Multidisciplinary and Global Geophysical Field Experience for Undergraduates

Science.gov (United States)

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

2007-05-01

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

Development of the near field geochemistry model

International Nuclear Information System (INIS)

Arcos, D.; Bruno, J.; Duro, L.; Grive, M.

2000-01-01

This report discusses in a quantitative manner the evolution of the near field geochemistry as a result of the interactions between two different introducing granitic groundwaters and the FEBEX bentonite as a buffer material. The two granitic groundwaters considered are: SR-5 water, sampled in a borehole at 500 m depth in Mina Ratones, and a mean composition of different granitic groundwaters from the iberian Massif. The steel canister has also been introduced by considering the iron corrosion in anoxic conditions. (Author)

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

Science.gov (United States)

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

2016-01-01

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

Geophysical methods in protected environments. Electrical resistivity tomography

International Nuclear Information System (INIS)

Rubio Sánchez-Aguililla, F.M.; Ramiro-Camacho, A.; Ibarra Torre, P.

2017-01-01

There is a strong interest in protecting the environment with the aim of its long term preservation. Sometimes the heritage value of these natural areas is related to their biodiversity as there are restricted ecosystems that depend directly on them. In other cases there a singular geological record might exist, essential for the understanding of certain processes affecting the planet, such as volcanic events or glacial periods. To achieve the protection and conservation of these areas it is necessary to generate knowledge about the distribution of geological materials and groundwater masses, to study the parameters that dominate the behaviour of these systems and then define those elements that require special protection or attention. In these protected environments, research methods with a minimal environmental impact should be used. Therefore, indirect methods, such as geophysical techniques, are reliable and complementary tools with a minimum environmental impact and are therefore useful for research these unique areas. The IGME has conducted several geophysical surveys in different protected environments in Spain with the aim of achieving a better understanding, and thus facilitate their preservation and exploitation in a sustainable manner. In this paper we present a review of some case studies where geophysical methods have been used. In all the cases electrical resistivity tomography has been the axis of the geophysical research and stands out due to its great effectiveness. The main objective of this communication is to divulgate and increase awareness of the important role that these geophysical methods can play in the sustainable study of these unique places. [es

Borehole geophysics in nuclear power plant siting

International Nuclear Information System (INIS)

Crosby, J.W.; Scott, J.D.

1979-01-01

Miniaturized borehole geophysical equipment designed for use in ground-water investigations can be adapted to investigations of nuclear power plant sites. This equipment has proved to be of value in preliminary and comprehensive studies of interior basins where thick sequences of Quaternary clastic sediment, occasionally with associated volcanic rocks, pose problems of stratigraphic correlation. The unconsolidated nature of the deposits generally requires that exploratory holes be cased, which ordinarily restricts the borehole geophysical studies to the radiation functions--natural gamma, gamma-gamma, neutron-gamma, and neutron-epithermal neutron logs. Although a single log response may be dominant in a given area, correlations derive from consideration of all log responses as a composite group. Because major correlations usually are based upon subtle differences in the physical properties of the penetrated sediment, high-resolution logging procedures are employed with some sacrifice of the quantitative perameters important to petroleum technology. All geophysical field data are recorded as hard copy and as digital information on punched paper tape

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

Science.gov (United States)

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

2016-12-01

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

Aqueous geochemistry in icy world interiors: Equilibrium fluid, rock, and gas compositions, and fate of antifreezes and radionuclides

Science.gov (United States)

Neveu, Marc; Desch, Steven J.; Castillo-Rogez, Julie C.

2017-09-01

The geophysical evolution of many icy moons and dwarf planets seems to have provided opportunities for interaction between liquid water and rock (silicate and organic solids). Here, we explore two ways by which water-rock interaction can feed back on geophysical evolution: the production or consumption of antifreeze compounds, which affect the persistence and abundance of cold liquid; and the potential leaching into the fluid of lithophile radionuclides, affecting the distribution of a long-term heat source. We compile, validate, and use a numerical model, implemented with the PHREEQC code, of the interaction of chondritic rock with pure water and with C, N, S-bearing cometary fluid, thought to be the materials initially accreted by icy worlds, and describe the resulting equilibrium fluid and rock assemblages at temperatures, pressures, and water-to-rock ratios of 0-200 ° C, 1-1000 bar, and 0.1-10 by mass, respectively. Our findings suggest that water-rock interaction can strongly alter the nature and amount of antifreezes, resulting in solutions rich in reduced nitrogen and carbon, and sometimes dissolved H2, with additional sodium, calcium, chlorine, and/or oxidized carbon. Such fluids can remain partially liquid down to 176 K if NH3 is present. The prominence of Cl in solution seems to hinge on its primordial supply in ices, which is unconstrained by the meteoritical record. Equilibrium assemblages, rich in serpentine and saponite clays, retain thorium and uranium radionuclides unless U-Cl or U-HCO3 complexing, which was not modeled, significantly enhances U solubility. However, the radionuclide 40 K can be leached at high water:rock ratio and/or low temperature at which K is exchanged with ammonium in minerals. We recommend the inclusion of these effects in future models of the geophysical evolution of ocean-bearing icy worlds. Our simulation products match observations of chloride salts on Europa and Enceladus; CI chondrites mineralogies; the observation of

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

International Nuclear Information System (INIS)

1991-01-01

Permitting and site selection activities for the proposed East Chestnut Ridge landfill, located on the Oak Ridge Reservation, have required additional hydrogeologic studies of two karst features. Geophysical testing methods were utilized for investigating these karst features. The objectives of the geophysical testing was to determine the feasibility of geophysical techniques for locating subsurface karst features and to determine if subsurface anomalies exist at the proposed landfill site. Two karst features, one lacking surface expression (sinkhole) but with a known solution cavity at depth (from previous hydrologic studies), and the other with surface expression were tested with surface geophysical methods. Four geophysical profiles, two crossing and centered over each karst feature were collected using both gravimetric and electrical resistivity techniques

Global Journal of Geological Sciences

African Journals Online (AJOL)

Global Journal of Geological Sciences is aimed at promoting research in all areas of Geological Sciences including geochemistry, geophysics, engineering geology, hydrogeology, petrology, mineralogy, geochronology, tectonics, mining, structural geology, marine geology, space science etc. Visit the Global Journal Series ...

Modal analysis and geochemistry of two sandstones of the Bhander ...

Indian Academy of Sciences (India)

and tectonic setting interpretations are based on modal analysis and whole rock geochemistry. The average ... that major part of the sediments were derived from the granitic source area. The sandstone ...... The geochemical gap shown by trace and rare ... of the Council of Scientific and Industrial Research,. New Delhi, in ...

Mining Pribram in science and technology

International Nuclear Information System (INIS)

1984-01-01

The Geomechanics session of the Symposium ''Mining Pribram in Science and Technology'' held from October 15 to 20, 1984 heard a total of 18 papers dealing with the effects of exploitation on the stability of the surrounding massif and surface, the protection of surface and deep mines, geophysical surveying, the measurement of deformations caUsed by undermining, the mathematical modelling of surface deformation and various measuring methods and methods of interpreting measured results. 4 papers are included into INIS. (B.S.)

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

Science.gov (United States)

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

2012-12-01

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

Overview of Effective Geophysical Methods Used in the Study of ...

African Journals Online (AJOL)

Abstract. The Application of various Geophysical Techniques for the assessment of the extent of ... ineffective Geophysical Method may not give true picture of the overall level of pollution in the .... stations shut down or maintenance which halt ...

The teaching of geophysics in Latin America: An updated assessment

Science.gov (United States)

Valencio, Daniel A.; Schneider, Otto

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

Simulating cold production by a coupled reservoir-geomechanics model with sand erosion

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.; Xue, S. [Petro-Geotech Inc., Calgary, AB (Canada)

2002-06-01

This paper presents a newly developed fully coupled reservoir-geomechanics model with sand erosion. Sand production occurs during aggressive production induced by the impact of viscous fluid flow and the in situ stress concentration near a wellbore, as well as by perforation tips in poorly consolidated formations. This compromises oil production, increases well completion costs, and reduces the life cycles of equipment down hole and on the surface. The proposed model can be used for sand production studies in conventional oil/gas reservoirs such as the North Sea as well as in heavy oil reservoirs such as in northwestern Canada. Instead of generating a high permeability network in reservoirs, the enhanced oil production is determined by the increase in the effective wellbore radius. This paper presents the general model. A detailed study on the capillary pressure and the impact of multiphase flow on sanding and erosion will be conducted at a later date. It appears that 2 phase flow can be important to elastoplasticity if no significant sand erosion has occurred. It was determined that high porosity is induced by erosion and capillary pressure. Two phase flow can be important when the built-up drag force carries sand-fluid slurry into the well. It is concluded that viscosity and flow velocity can help estimate the slurry transport, sand rate and enhanced oil production. 22 refs., 3 tabs., 11 figs.

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

Science.gov (United States)

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

2016-12-01

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

Mobile geophysics for searching and exploration of Domanic hydrocarbon deposits

Science.gov (United States)

Borovsky, M. Ya; Uspensky, B. V.; Valeeva, S. E.; Borisov, A. S.

2018-05-01

There are noted features of shale hydrocarbons occurrence. It is shown the role of geophysical prospecting in the geological prospecting process for non-traditional sources of hydrocarbon. There are considered the possibilities of non-seismic methods for forecasting, prospecting, exploration and preparation of Domanikovian hydrocarbons accumulations for exploration. It is emphasized the need for geophysical studies of tectonic disturbances. Modern aerogeophysical instrumentation and methodological support allows to combine high-precision magneto-prospecting with gravimetric and gamma spectrometry. This combination of geophysical methods contributes to the diagnosis of active and latent faults.

Radon, gas geochemistry, groundwater, and earthquakes

Energy Technology Data Exchange (ETDEWEB)

King, Chi-Yu [Power Reactor and Nuclear Fuel Development Corp., Tono Geoscience Center, Toki, Gifu (Japan)

1998-12-31

Radon monitoring in groundwater, soil air, and atmosphere has been continued in many seismic areas of the world for earthquake-prediction and active-fault studies. Some recent measurements of radon and other geochemical and hydrological parameters have been made for sufficiently long periods, with reliable instruments, and together with measurements of meteorological variables and solid-earth tides. The resultant data are useful in better distinguishing earthquake-related changes from various background noises. Some measurements have been carried out in areas where other geophysical measurements are being made also. Comparative studies of various kinds of geophysical data are helpful in ascertaining the reality of the earthquake-related and fault-related anomalies and in understanding the underlying mechanisms. Spatial anomalies of radon and other terrestrial gasses have been observed for many active faults. Such observations indicate that gas concentrations are very much site dependent, particularly on fault zones where terrestrial fluids may move vertically. Temporal anomalies have been reliably observed before and after some recent earthquakes, including the 1995 Kobe earthquake, and the general pattern of anomaly occurrence remains the same as observed before: They are recorded at only relatively few sensitive sites, which can be at much larger distances than expected from existing earthquake-source models. The sensitivity of a sensitive site is also found to be changeable with time. These results clearly show the inadequacy of the existing dilatancy-fluid diffusion and elastic-dislocation models for earthquake sources to explain earthquake-related geochemical and geophysical changes recorded at large distances. (J.P.N.)

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

Science.gov (United States)

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

Geophysical methods for evaluation of plutonic rocks

International Nuclear Information System (INIS)

Gibb, R.A.; Scott, J.S.

1986-04-01

Geophysical methods are systematically described according to the physical principle and operational mode of each method, the type of information produced, limitations of a technical and/or economic nature, and the applicability of the method to rock-mass evaluation at Research Areas of the Nuclear Fuel Waste Management Program. The geophysical methods fall into three categories: (1) airborne and other reconnaissance surveys, (2) detailed or surface (ground) surveys, and (3) borehole or subsurface surveys. The possible roles of each method in the site-screening and site-evaluation processes of disposal vault site selection are summarized

Geophysical experiments at Mariano Lake uranium orebody

International Nuclear Information System (INIS)

Thompson, D.T.

1980-01-01

Several geophysical experiments were performed over the Mariano Lake orebody before mining. Surface self-potential methods, surface-to-hole induced-polarization methods, and reflection-seismic methods were used. These geophysical techniques provided data which relate to the conceptual model of this orebody. Currents generated in the productive formation by oxidation-reduction reactions do not generate measurable potential anomalies at the surface. Surface-to-hole induced-polarization measurements apparently can detect an oxidation-reduction front in the vicinity of an exploration borehole. Reflection-seismic techniques can provide information concening the paleostructure of the area

Geomechanical, Hydraulic and Thermal Characteristics of Deep Oceanic Sandy Sediments Recovered during the Second Ulleung Basin Gas Hydrate Expedition

Directory of Open Access Journals (Sweden)

Yohan Cha

2016-09-01

Full Text Available This study investigates the geomechanical, hydraulic and thermal characteristics of natural sandy sediments collected during the Ulleung Basin gas hydrate expedition 2, East Sea, offshore Korea. The studied sediment formation is considered as a potential target reservoir for natural gas production. The sediments contained silt, clay and sand fractions of 21%, 1.3% and 77.7%, respectively, as well as diatomaceous minerals with internal pores. The peak friction angle and critical state (or residual state friction angle under drained conditions were ~26° and ~22°, respectively. There was minimal or no apparent cohesion intercept. Stress- and strain-dependent elastic moduli, such as tangential modulus and secant modulus, were identified. The sediment stiffness increased with increasing confining stress, but degraded with increasing strain regime. Variations in water permeability with water saturation were obtained by fitting experimental matric suction-water saturation data to the Maulem-van Genuchen model. A significant reduction in thermal conductivity (from ~1.4–1.6 to ~0.5–0.7 W·m−1·K−1 was observed when water saturation decreased from 100% to ~10%–20%. In addition, the electrical resistance increased quasi-linearly with decreasing water saturation. The geomechanical, hydraulic and thermal properties of the hydrate-free sediments reported herein can be used as the baseline when predicting properties and behavior of the sediments containing hydrates, and when the hydrates dissociate during gas production. The variations in thermal and hydraulic properties with changing water and gas saturation can be used to assess gas production rates from hydrate-bearing deposits. In addition, while depressurization of hydrate-bearing sediments inevitably causes deformation of sediments under drained conditions, the obtained strength and stiffness properties and stress-strain responses of the sedimentary formation under drained loading conditions

Coupled Flow and Geomechanics Modeling of Slow Earthquakes: Application to Slow Slip Events (SSE) in the Guerrero Gap, Mexico

Science.gov (United States)

Alves da Silva Junior, J.; Frank, W.; Castineira, D.; Jha, B.; Juanes, R.

2016-12-01

Three major cycles of slow slip events (SSE) have been reported since the early 2000s in the Guerrero gap, Mexico, on the boundary between the Cocos and North American plates. Analysis of teleseismic waveforms recorded on a dense temporary seismic network in the Guerrero gap have found low S-wave velocity and high Vp/Vs ratios at the depths corresponding to the sources of SSE, implying the possible presence of fluids and thus an active dewatering process that may result in near-lithostatic pore pressure at the plate interface. Here we use coupled flow and geomechanics analysis of the Guerrero gap to model transient changes in the stress field in the subduction zone as a result of pore pressure fluctuations and potential fluid flow along the subduction interface. Our computational modeling approach couples a multiphase flow simulator with a mechanical simulator using the unconditionally stable fixed stress scheme for the sequential solution of the two-way coupling between flow and geomechanics (Jha and Juanes, 2014). We assume quasi-static mechanical deformation and neglect the inertial term in the solid momentum balance equation—an approximation that is valid to model SSE assuming aseismic slip. We represent the subducting Cocos fault as a surface embedded in a three-dimensional medium, and use zero thickness interface elements to accurately model stick-slip behavior under dynamically evolving fluid pressure and fault strength. We employ the rate- and state-dependent friction model in the evolution of the coefficient of friction. We calibrate our model using two distinct datasets—GPS data and tremor catalogs in the area of Guerrero gap—and by separately constraining the rate of water production from a model of mineral hydration with depth. Our quantitative modeling approach furnishes a mechanistic understanding of the relationship between pore pressure evolution, stress transfer and tremor migration, and helps elucidate the origin of SSE in this area.

Geophysical mapping of complex glaciogenic large-scale structures

DEFF Research Database (Denmark)

Høyer, Anne-Sophie

2013-01-01

This thesis presents the main results of a four year PhD study concerning the use of geophysical data in geological mapping. The study is related to the Geocenter project, “KOMPLEKS”, which focuses on the mapping of complex, large-scale geological structures. The study area is approximately 100 km2...... data types and co-interpret them in order to improve our geological understanding. However, in order to perform this successfully, methodological considerations are necessary. For instance, a structure indicated by a reflection in the seismic data is not always apparent in the resistivity data...... information) can be collected. The geophysical data are used together with geological analyses from boreholes and pits to interpret the geological history of the hill-island. The geophysical data reveal that the glaciotectonic structures truncate at the surface. The directions of the structures were mapped...

Challenges, uncertainties, and issues facing gas production from gas-hydrate deposits

Science.gov (United States)

Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswel, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.B.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.A.

2011-01-01

The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas-hydrate (GH) petroleum system; to discuss advances, requirements, and suggested practices in GH prospecting and GH deposit characterization; and to review the associated technical, economic, and environmental challenges and uncertainties, which include the following: accurate assessment of producible fractions of the GH resource; development of methods for identifying suitable production targets; sampling of hydrate-bearing sediments (HBS) and sample analysis; analysis and interpretation of geophysical surveys of GH reservoirs; well-testing methods; interpretation of well-testing results; geomechanical and reservoir/well stability concerns; well design, operation, and installation; field operations and extending production beyond sand-dominated GH reservoirs; monitoring production and geomechanical stability; laboratory investigations; fundamental knowledge of hydrate behavior; the economics of commercial gas production from hydrates; and associated environmental concerns. ?? 2011 Society of Petroleum Engineers.

Challenges, uncertainties and issues facing gas production from gas hydrate deposits

Energy Technology Data Exchange (ETDEWEB)

Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswell, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.

2010-11-01

The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas hydrate petroleum system, to discuss advances, requirement and suggested practices in gas hydrate (GH) prospecting and GH deposit characterization, and to review the associated technical, economic and environmental challenges and uncertainties, including: the accurate assessment of producible fractions of the GH resource, the development of methodologies for identifying suitable production targets, the sampling of hydrate-bearing sediments and sample analysis, the analysis and interpretation of geophysical surveys of GH reservoirs, well testing methods and interpretation of the results, geomechanical and reservoir/well stability concerns, well design, operation and installation, field operations and extending production beyond sand-dominated GH reservoirs, monitoring production and geomechanical stability, laboratory investigations, fundamental knowledge of hydrate behavior, the economics of commercial gas production from hydrates, and the associated environmental concerns.

Geophysical Exploration. New site exploration method

Energy Technology Data Exchange (ETDEWEB)

Imai, Tsuneo; Otomo, Hideo; Sakayama, Toshihiko

1988-07-25

Geophysical exploration is used for geologic survey to serve purposes in civil engineering. New methods are being developed inside and outside Japan and are used to serve various purposes. This paper discusses recently developed techniques based on the measurement of seismic waves and electric potential. It also explains seismic tomography, radar tomography, and resistivity tomography which are included in the category of geotomography. At present, effort is being made to apply geophysical exploration technology to problems which were considered to be unsuitable for conventional exploration techniques. When such effort proceeds successfully, it is necessary to develop technology for presenting results quickly and exploration equipment which can work in various conditions. (10 figs, 15 refs)

History of geophysical studies at the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico

International Nuclear Information System (INIS)

Borns, D.J.

1997-01-01

A variety of geophysical methods including the spectrum of seismic, electrical, electromagnetic and potential field techniques have supported characterization, monitoring and experimental studies at the Waste Isolation Pilot Plant (WIPP). The geophysical studies have provided significant understanding of the nature of site deformation, tectonics and stability. Geophysical methods have delineated possible brine reservoirs beneath the underground facility and have defined the disturbed rock zone that forms around underground excavations. The role of geophysics in the WIPP project has evolved with the project. The early uses were for site characterization to satisfy site selection criteria or factors. As the regulatory framework for WIPP grew since 1980, the geophysics program supported experimental and field programs such as Salado hydrogeology and underground room systems and excavations. In summary, the major types of issues that geophysical studies addressed for WIPP are: Site Characterization; Castile Brine Reservoirs; Rustler/Dewey Lake Hydrogeology; Salado Hydrogeology; and Excavation Effects. The nature of geophysics programs for WIPP has been to support investigation rather than being the principal investigation itself. The geophysics program has been used to define conceptual models (e.g., the Disturbed Rock Zone-DRZ) or to test conceptual models (e.g., high transmissivity zones in the Rustler Formation). The geophysics program primarily supported larger characterization and experimental programs. Funding was not available for the complete documentation and interpretation. Therefore, a great deal of the geophysics survey information resides in contractor reports

Uranium geochemistry, mineralogy, geology, exploration and resources

International Nuclear Information System (INIS)

De Vivo, B.

1984-01-01

This book comprises papers on the following topics: history of radioactivity; uranium in mantle processes; transport and deposition of uranium in hydrothermal systems at temperatures up to 300 0 C: Geological implications; geochemical behaviour of uranium in the supergene environment; uranium exploration techniques; uranium mineralogy; time, crustal evolution and generation of uranium deposits; uranium exploration; geochemistry of uranium in the hydrographic network; uranium deposits of the world, excluding Europe; uranium deposits in Europe; uranium in the economics of energy; role of high heat production granites in uranium province formation; and uranium deposits

United States Geological Survey uranium and thorium resource assessment and exploration research program, fiscal year 1980

International Nuclear Information System (INIS)

Offield, T.W.

1979-01-01

Research is being conducted by the USGS for the NURE program in six fields: geochemistry and mineralogy, sedimentary environments, igneous and metamorphic environments, geophysical exploration techniques, U resource assessment, and Th resource assessment. Some FY 1979 research results are reported and discussed

Some case studies of geophysical exploration of archaeological sites in Yugoslavia

Science.gov (United States)

Komatina, Snezana; Timotijevic, Zoran

1999-03-01

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

Evidence for a critical Earth: the New Geophysics

Science.gov (United States)

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

COTHERM: Geophysical Modeling of High Enthalpy Geothermal Systems

Science.gov (United States)

Grab, Melchior; Maurer, Hansruedi; Greenhalgh, Stewart

2014-05-01

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

Geochemistry of impact glasses and target rocks from the Zhamanshin impact structure, Kazakhstan: Implications for mixing of target and impactor matter

Czech Academy of Sciences Publication Activity Database

Jonášová, Šárka; Ackerman, Lukáš; Žák, Karel; Skála, Roman; Ďurišová, Jana; Deutsch, A.; Magna, T.

2016-01-01

Roč. 190, 1 October (2016), s. 239-264 ISSN 0016-7037 R&D Projects: GA ČR GA13-22351S Institutional support: RVO:67985831 Keywords : impact glass * irghizites * geochemistry * meteoritic component * siderophile elements * osmium isotopes * Zhamanshin Subject RIV: DD - Geochemistry Impact factor: 4.609, year: 2016

Inverse problems of geophysics

International Nuclear Information System (INIS)

Yanovskaya, T.B.

2003-07-01

This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

Monitoring Global Geophysical Fluids by Space Geodesy

Science.gov (United States)

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.

History of geophysical studies at the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico

International Nuclear Information System (INIS)

Borns, D.J.

1997-01-01

A variety of geophysical methods including the spectrum of seismic, electrical, electromagnetic and potential field techniques have used support characterization, monitoring and experimental studies at the Waste Isolation Pilot Plant (WIPP). The geophysical studies have provided significant understanding of the nature of site deformation, tectonics and stability. Geophysical methods have delineated possible brine reservoirs beneath the underground facility and have defined the disturbed rock zone that forms around underground excavations. The role of geophysics in the WIPP project has evolved with the project. The early uses were for site characterization to satisfy site selection criteria or factors. As the regulatory framework for WIPP grew since 1980, the geophysics program was focused on support of experimental and field programs such as Salado hydrogeology and underground room systems and excavations. In summary, the major types of issues that geophysical studies addressed for WIPP are: Issue 1: Site Characterization; Issue 2: Castile Brine Reservoirs; Issue 3: Rustler /Dewey Lake Hydrogeology; Issue 4: Salado Hydrogeology; and Issue 5: Excavation Effects. The nature of geophysics program for WIPP has been to support investigation rather than being the principal investigation itself. The geophysics program has been used to define conceptual models (e.g., the Disturbed Rock Zone-DRZ) or to test conceptual models (e.g., high transmissivity zones in the Rustler Formation). An effect of being a support program is that as new project priorities arose the funding for the geophysics program was limited and withdrawn. An outcome is that much of the geophysics survey information resides in contractor reports since final interpretation reports were not funded

Solar wind monitor—a school geophysics project

Science.gov (United States)

Robinson, Ian

2018-05-01

Described is an established geophysics project to construct a solar wind monitor based on a nT resolution fluxgate magnetometer. Low-cost and appropriate from school to university level it incorporates elements of astrophysics, geophysics, electronics, programming, computer networking and signal processing. The system monitors the earth’s field in real-time uploading data and graphs to a website every few minutes. Modular design encourages construction and testing by teams of students as well as expansion and refinement. The system has been tested running unattended for months at a time. Both the hardware design and software is published as open-source [1, 10].

Common interests bind AGU and geophysical groups around the globe

Science.gov (United States)

McEntee, Christine

2012-02-01

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

Geophysical and solar activity indices

Science.gov (United States)

Bossy, L.; Lemaire, J.

1984-04-01

A large number of geophysicists try to correlate their observations with one or even a series of different geophysical or solar activity indices. Yet the right choice of the most appropriate index with which to correlate depends mainly on our understanding of the physical cause-effect relationship between the new set of observations and the index chosen. This best choice will therefore depend on our good understanding of the methods of measurement and derivation of the adopted index in such correlative studies. It relies also on our awareness of the range of applicability of the indices presently available as well as on our understanding of their limitations. It was to achieve these goals that a series of general lectures on geophysical and solar activity indices was organized by L. Bossy and J. Lemaire (Institut d'Aeronomie Spatiale de Belgique (IASB), Brussels), March 26-29, 1984 at Han-sur-Lesse, Belgium.

Intense rockburst impacts in deep underground construction and their prevention

Czech Academy of Sciences Publication Activity Database

Mazaira, Alejandro; Koníček, Petr

2015-01-01

Roč. 52, č. 10 (2015), s. 1426-1439 ISSN 0008-3674. [International Colloquium on Geomechanics and Geophysics /5./. Karolinka, 25.06.2014-27.06.2014] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : rockburst * in situ stress * induced stress * destress blasting * yielding support Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 1.877, year: 2015 http://www.nrcresearchpress.com/doi/full/10.1139/cgj-2014-0359#.VgqBTZc70ms

Monitoring of Underground Coal Gasification

Energy Technology Data Exchange (ETDEWEB)

Yang, X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wagoner, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramirez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2012-08-31

For efficient and responsible UCG operations, a UCG process must be monitored in the following three categories: 1) process parameters such as injection and product gas flow rates, temperature, pressure and syngas content and heating value; 2) geomechanical parameters, e.g., cavity and coal seam pressures, cavity development, subsidence and ground deformation; and 3) environmental parameters, e.g., groundwater chemistry and air quality. This report focuses on UCG monitoring with geophysical techniques that can contribute to monitoring of subsurface temperature, cavity development, burn front, subsidence and deformation.

Rotation of principal axes and changes of stress due to mine-induced stresses

Czech Academy of Sciences Publication Activity Database

Ptáček, Jiří; Koníček, Petr; Staš, Lubomír; Waclawik, Petr; Kukutsch, Radovan

2015-01-01

Roč. 52, č. 10 (2015), s. 1440-1447 ISSN 0008-3674. [International Colloquium on Geomechanics and Geophysics /5./. Karolinka, 25.06.2014-27.06.2014] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : mining * principal stress * stress distribution * modified overcoring Subject RIV: DH - Mining , incl. Coal Mining Impact factor: 1.877, year: 2015 http://www.nrcresearchpress.com/doi/full/10.1139/cgj-2014-0364#.VgqDPpc70mt

Intense rockburst impacts in deep underground construction and their prevention

Czech Academy of Sciences Publication Activity Database

Mazaira, Alejandro; Koníček, Petr

2015-01-01

Roč. 52, č. 10 (2015), s. 1426-1439 ISSN 0008-3674. [International Colloquium on Geomechanics and Geophysics /5./. Karolinka, 25.06.2014-27.06.2014] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support : RVO:68145535 Keywords : rockburst * in situ stress * induced stress * destress blasting * yielding support Subject RIV: DH - Mining , incl. Coal Mining Impact factor: 1.877, year: 2015 http://www.nrcresearchpress.com/doi/full/10.1139/cgj-2014-0359#.VgqBTZc70ms

Geology, geochemistry, and geophysics of the Fry Canyon uranium/copper project site, southeastern Utah - Indications of contaminant migration

Science.gov (United States)

Otton, James K.; Zielinski, Robert A.; Horton, Robert J.

2010-01-01

The Fry Canyon uranium/copper project site in San Juan County, southeastern Utah, was affected by the historical (1957-68) processing of uranium and copper-uranium ores. Relict uranium tailings and related ponds, and a large copper heap-leach pile at the site represent point sources of uranium and copper to local soils, surface water, and groundwater. This study was designed to establish the nature, extent, and pathways of contaminant dispersion. The methods used in this study are applicable at other sites of uranium mining, milling, or processing. The uranium tailings and associated ponds sit on a bench that is as much as 4.25 meters above the level of the adjacent modern channel of Fry Creek. The copper heap leach pile sits on bedrock just south of this bench. Contaminated groundwater from the ponds and other nearby sites moves downvalley and enters the modern alluvium of adjacent Fry Creek, its surface water, and also a broader, deeper paleochannel that underlies the modern creek channel and adjacent benches and stream terraces. The northern extent of contaminated groundwater is uncertain from geochemical data beyond an area of monitoring wells about 300 meters north of the site. Contaminated surface water extends to the State highway bridge. Some uranium-contaminated groundwater may also enter underlying bedrock of the Permian Cedar Mesa Sandstone along fracture zones. Four dc-resistivity surveys perpendicular to the valley trend were run across the channel and its adjacent stream terraces north of the heap-leach pile and ponds. Two surveys were done in a small field of monitoring wells and two in areas untested by borings to the north of the well field. Bedrock intercepts, salt distribution, and lithologic information from the wells and surface observations in the well field aided interpretation of the geophysical profiles there and allowed interpretation of the two profiles not tested by wells. The geophysical data for the two profiles to the north of the

Mining inventory of Uruguay : Uranium; Inventario Minero Nacional : Uranio

Energy Technology Data Exchange (ETDEWEB)

NONE

1983-07-01

With the aim of Uruguay Uranium prospecting in this document has been summarized the following items: lithostratigraphy, background, economics aspects, radiation measuring, geochemistry, geophysics in Yerba Sola, Magnolia, Paso Amarillo, La Mercedes, Puntas de Abrojal, Las Chircas, La Divisa, Chuy, Apretado and Frayle Muerto.

Mining inventory of Uruguay : Uranium

International Nuclear Information System (INIS)

1983-01-01

With the aim of Uruguay Uranium prospecting in this document has been summarized the following items: lithostratigraphy, background, economics aspects, radiation measuring, geochemistry, geophysics in Yerba Sola, Magnolia, Paso Amarillo, La Mercedes, Puntas de Abrojal, Las Chircas, La Divisa, Chuy, Apretado and Frayle Muerto

Petrology and geochemistry of the marbles and calcosilicated rocks from Ipira, Bahia - Brazil

International Nuclear Information System (INIS)

Oliveira, M.A.F.T. de.

1976-01-01

This work explains a study of marbles and diopsitites from Serra das Panelas, Ipira, Bahia, Brazil. Petrographic analysis, chemistry some elements, trace elements and rare earths, isotopic analysis of Strontium, carbon and oxigen, and geochronological determinations were done. The ages founded correspond to Transamazonic Orogenetic cicle, with Archean age, confirmed by the 18 O values found, which give to marble, ages about 2.500 my. The mineralogy and the texture give to marble an invulgar aspect, making a confusion with carbonate. The petrochemical data and the geochemistry of 13 C and 18 O isotopes showed that the marble and diopsitites was formed from the old marine carbonates. The geochemistry of rare earth suggests a strong correlation with carbonitic and alkaline rocks. An hybrid origem to this rocks is proposed. (C.D.G.) [pt

SRP baseline hydrogeologic investigation: Aquifer characterization. Groundwater geochemistry of the Savannah River Site and vicinity

Energy Technology Data Exchange (ETDEWEB)

Strom, R.N.; Kaback, D.S.

1992-03-31

An investigation of the mineralogy and chemistry of the principal hydrogeologic units and the geochemistry of the water in the principal aquifers at Savannah River Site (SRS) was undertaken as part of the Baseline Hydrogeologic Investigation. This investigation was conducted to provide background data for future site studies and reports and to provide a site-wide interpretation of the geology and geochemistry of the Coastal Plain Hydrostratigraphic province. Ground water samples were analyzed for major cations and anions, minor and trace elements, gross alpha and beta, tritium, stable isotopes of hydrogen, oxygen, and carbon, and carbon-14. Sediments from the well borings were analyzed for mineralogy and major and minor elements.

Geophysical logging for groundwater investigations in Southern Thailand

Directory of Open Access Journals (Sweden)

Phongpiyah Klinmanee

2012-09-01

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

Hydrocarbon Reservoir Identification in Volcanic Zone by using Magnetotelluric and Geochemistry Information

Science.gov (United States)

Firda, S. I.; Permadi, A. N.; Supriyanto; Suwardi, B. N.

2018-03-01

The resistivity of Magnetotelluric (MT) data show the resistivity mapping in the volcanic reservoir zone and the geochemistry information for confirm the reservoir and source rock formation. In this research, we used 132 data points divided with two line at exploration area. We used several steps to make the resistivity mapping. There are time series correction, crosspower correction, then inversion of Magnetotelluric (MT) data. Line-2 and line-3 show anomaly geological condition with Gabon fault. The geology structure from the resistivity mapping show the fault and the geological formation with the geological rock data mapping distribution. The geochemistry information show the maturity of source rock formation. According to core sample analysis information, we get the visual porosity for reservoir rock formation in several geological structure. Based on that, we make the geological modelling where the potential reservoir and the source rock around our interest area.

Preliminary evaluation of alterant geophysical tomography in welded tuff

International Nuclear Information System (INIS)

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

1985-01-01

The ability of alterant geophysical tomography to delineate flow paths in a welded tuff rock mass has been preliminarily evaluated based on the results of a field experiment. Electromagnetic measurements were made before, during and after a water-based, dye tracer flowed through the rock mass. Alterant geophysical tomographs were generated and compared with independent evidence - borescope logs, neutron logs and dyed rock samples. Anomalies present in the tomograph match the location and orientation of fractures mapped with a borescope. The location of tracer-stained fractures coincides with the location of some image anomalies; other geophysical anomalies exist where tracer-stained fractures were not observed, perhaps due to poor core recovery. Additional drilling to locate stained flow paths and other experiments are planned so that the applicability of the technique can be further evaluated

Joint inversion of geophysical and hydrological data for improved subsurface characterization

International Nuclear Information System (INIS)

Kowalsky, Michael B.; Chen, Jinsong; Hubbard, Susan S.

2006-01-01

Understanding fluid distribution and movement in the subsurface is critical for a variety of subsurface applications, such as remediation of environmental contaminants, sequestration of nuclear waste and CO2, intrusion of saline water into fresh water aquifers, and the production of oil and gas. It is well recognized that characterizing the properties that control fluids in the subsurface with the accuracy and spatial coverage needed to parameterize flow and transport models is challenging using conventional borehole data alone. Integration of conventional borehole data with more spatially extensive geophysical data (obtained from the surface, between boreholes, and from surface to boreholes) shows promise for providing quantitative information about subsurface properties and processes. Typically, estimation of subsurface properties involves a two-step procedure in which geophysical data are first inverted and then integrated with direct measurements and petrophysical relationship information to estimate hydrological parameters. However, errors inherent to geophysical data acquisition and inversion approaches and errors associated with petrophysical relationships can decrease the value of geophysical data in the estimation procedure. In this paper, we illustrate using two examples how joint inversion approaches, or simultaneous inversion of geophysical and hydrological data, offer great potential for overcoming some of these limitations

BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.

Science.gov (United States)

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.

On models in the geochemistry of isotopes

International Nuclear Information System (INIS)

Wetzel, K.

1978-01-01

Models are playing an increasing role in the deepening of our understanding of the laws of occurrence of stable and radioactive isotopes in nature. The properties of concrete global and regional models of the geochemistry of isotopes are derived from a general model characterizing the cycling of chemical elements and their isotopes in nature. The importance of global models as well as the relationships between global and regional models are considered. The introduction of a parameter describing the velocity of both mass and isotope transfer, taking into consideration the global resources, renders possible the linkage of global models with regional ones. (author)

Geophysical interpretation using integral equations

CERN Document Server

Eskola, L

1992-01-01

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

Motivation, description, and summary status of geomechanical and geochemical modeling studies in Task D of the International DECOVALEX-THMC Project

International Nuclear Information System (INIS)

Birkholzer, J.T.; Barr, D.; Rutqvist, J.; Sonnenthal, E.

2005-01-01

The DECOVALEX project is an international cooperative project initiated by SKI, the Swedish Nuclear Power Inspectorate, with participation of about 10 international organizations. The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled thermo-hydro-mechanical-chemical (THMC) processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. One of the research tasks, initiated in 2004 by the U.S. Department of Energy (DOE), addresses the long-term impact of geomechanical and geochemical processes on the flow conditions near waste emplacement tunnels. Within this task, four international research teams conduct predictive analysis of the coupled processes in two generic repositories, using multiple approaches and different computer codes. Below, we give an overview of the research task and report its current status

Archaeological Feedback as a Research Methodology in Near-Surface Geophysics

Science.gov (United States)

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

2005-05-01

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

Addressing the difficulty of changing fields in geophysics

Science.gov (United States)

Civilini, F.; Savage, M. K.

2014-12-01

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

United States Geological Survey: uranium and thorium resource assessment and exploration research program, fiscal year 1979

International Nuclear Information System (INIS)

Offield, T.W.

1978-01-01

Objectives and current plans are given for the following projects: uranium geochemistry and mineralogy; uranium in sedimentary environments; uranium in igneous and metamorphic environments; geophysical techniques in uranium and thorium exploration; and thorium investigations and resource assessment. Selected noteworthy results of FY 1978 research are given

Object-Oriented Programming When Developing Software in Geology and Geophysics

Science.gov (United States)

Ahmadulin, R. K.; Bakanovskaya, L. N.

2017-01-01

The paper reviews the role of object-oriented programming when developing software in geology and geophysics. Main stages have been identified at which it is worthwhile to apply principles of object-oriented programming when developing software in geology and geophysics. The research was based on a number of problems solved in Geology and Petroleum Production Institute. Distinctive features of these problems are given and areas of application of the object-oriented approach are identified. Developing applications in the sphere of geology and geophysics has shown that the process of creating such products is simplified due to the use of object-oriented programming, firstly when designing structures for data storage and graphical user interfaces.

The Role of Geochemistry and Basin Modelling in the Exploration of Mature province

International Nuclear Information System (INIS)

Katz, A.J.

2002-01-01

Petroleum geochemistry and basin modelling has been an important tool in the reduction of risks in poorly explored basins. Historically the role of geochemistry is usually reduced once production is established and often in mature province is nonexistent. However, attempts to add reserves in mature provinces require an expansion of exploration programs based on new play concepts. Consequently, there is a clear role for geochemistry and basin modelling as this revitalization occurs.These new basin modelling and geochemical programs are aimed at answering three questions: . Can the petroleum system be extended? . Is a change in hydrocarbon character to be expected? . How much hydrocarbon potential remains?Unlike frontier exploration a significant sample base is normally available that can be used to more effectively constrain interpretations. Such programs have clearly aided exploration in the Niger Delta. For example, the collection of an extensive piston core dataset in conjunction with a basin modelling program provided strong support for the Niger Delta's petroleum system extending into deep water areas. While the geochemical character of the oils established the presence of multiple effective generative systems, each of which has different source characteristics and often-different ages. This information constraints model construction and hydrocarbon volume estimates. Oil data also established the importance of phase segregation. The presence of fractionated oils and maturation modelling results provides evidence for deeper hydrocarbon potential within the geographic limits of established hydrocarbon pays

Survey of geophysical techniques for site characterization in basalt, salt and tuff

International Nuclear Information System (INIS)

Jones, G.M.; Blackey, M.E.; Rice, J.E.; Murphy, V.J.; Levine, E.N.; Fisk, P.S.; Bromery, R.W.

1987-07-01

Geophysical techniques may help determine the nature and extent of faulting in the target areas, along with structural information that would be relevant to questions concerning the future integrity of a high-level-waste repository. Chapters focus on particular geophysical applications to four rock types - basalt, bedded salt, domal salt and tuff - characteristic of the sites originally proposed for site characterization. No one geophysical method can adequately characterize the geological structure beneath any site. The seismic reflection method, which is generally considered to be the most incisive of the geophysical techniques, has to date provided only marginal information on structure at the depth of the proposed repository at the Hanford, Washington, site, and no useful results at all at the Yucca Mountain, Nevada, site. This result is partially due to geological complexity beneath these sites, but may also be partially attributed to the use of inappropriate acquisition and processing parameters. To adequately characterize a site using geophysics, modifications will have to be made to standard techniques to emphasize structural details at the depths of interest. 137 refs., 43 figs., 4 tabs

The Legacy of Benoit Mandelbrot in Geophysics

Science.gov (United States)

Turcotte, D. L.

2001-12-01

The concept of fractals (fractional dimension) was introduced by Benoit Mandelbrot in his famous 1967 Science paper. The initial application was to the length of the coastline of Britain. A milestone in the appreciation of the fractal concept by geophysicists was the Union session of the AGU on fractals led off by Benoit in 1986. Although fractals have found important applications in almost every branch of the physical, biological, and social sciences, fractals have been particularly useful in geophysics. Drainage networks are fractal. The frequency-magnitude distribution of earthquakes is fractal. The scale invariance of landscapes and many other geological processes is due to the applicability of power-law (fractal) distributions. Clouds are often fractal. Porosity distributions are fractal. In an almost independent line of research, Benoit in collaboration with James Wallace and others developed the concept of self-affine fractals. The original applications were primarily to time series in hydrology and built on the foundation laid by Henry Hurst. Fractional Gaussian noises and fractional Brownian motions are ubiquitous in geophysics. These are expressed in terms of the power-law relation between the power-spectral density S and frequency f, S ~ f{ β }, examples are β = 0 (white noise), β = 1 (1/f noise), β = 2 (Brownian motion). Of particular importance in geophysics are fractional noises with β = 0.5, these are stationary but have long-range persistent and have a Hurst exponent H = 0.7. Examples include river flows, tree rings, sunspots, varves, etc. Two of Benoit Mandelbrot's major contributions in geophysics as in other fields are: (1) an appreciation of the importance of fat-tail, power-law (fractal) distributions and (2) an appreciation of the importance of self-similar long-range persistence in both stationary time series (noises) and nonstationary time series (walks).

Geophysical investigation, Salmon Site, Lamar County, Mississippi

International Nuclear Information System (INIS)

1995-02-01

Geophysical surveys were conducted in 1992 and 1993 on 21 sites at the Salmon Site (SS) located in Lamar County, Mississippi. The studies are part of the Remedial Investigation/Feasibility Study (RI/FS) being conducted by IT Corporation for the U.S. Department of Energy (DOE). During the 1960s, two nuclear devices and two chemical tests were detonated 826 meters (in) (2710 feet [ft]) below the ground surface in the salt dome underlying the SS. These tests were part of the Vela Uniform Program conducted to improve the United States capability to detect, identify, and locate underground nuclear detonations. The RI/FS is being conducted to determine if any contamination is migrating from the underground shot cavity in the salt dome and if there is any residual contamination in the near surface mud and debris disposal pits used during the testing activities. The objective of the surface geophysical surveys was to locate buried debris, disposal pits, and abandoned mud pits that may be present at the site. This information will then be used to identify the locations for test pits, cone penetrometer tests, and drill hole/monitor well installation. The disposal pits were used during the operation of the test site in the 1960s. Vertical magnetic gradient (magnetic gradient), electromagnetic (EM) conductivity, and ground-penetrating radar (GPR) surveys were used to accomplish these objectives. A description of the equipment used and a theoretical discussion of the geophysical methods are presented Appendix A. Because of the large number of figures relative to the number of pages of text, the geophysical grid-location maps, the contour maps of the magnetic-gradient data, the contour maps of the EM conductivity data, and the GPR traverse location maps are located in Appendix B, Tabs I through 22. In addition, selected GPR records are located in Appendix C

On the quantitative determination of coal seam thickness by means of in-seam seismic surveys

Czech Academy of Sciences Publication Activity Database

Schott, W.; Waclawik, Petr

2015-01-01

Roč. 52, č. 10 (2015), s. 1496-1504 ISSN 0008-3674. [International Colloquium on Geomechanics and Geophysics /5./. Karolinka, 25.06.2014-27.06.2014] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : in-seam seismic (ISS) * ISS wave * Love wave * coal seam thickness * dispersion Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 1.877, year: 2015 http://www.nrcresearchpress.com/doi/full/10.1139/cgj-2014-0466#.VgqE1Zc70mt

Application of alternative methods for determination of rock quality designation (RQD) index: a case study from the Rožná I uranium mine, Strážek Moldanubicum, Bohemian Massif, Czech Republic

Czech Academy of Sciences Publication Activity Database

Vavro, Martin; Souček, Kamil; Staš, Lubomír; Waclawik, Petr; Vavro, Leona; Koníček, Petr; Ptáček, Jiří

2015-01-01

Roč. 52, č. 10 (2015), s. 1466-1476 ISSN 0008-3674. [International Colloquium on Geomechanics and Geophysics /5./. Karolinka, 25.06.2014-27.06.2014] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : rock quality designation (RQD) index * geotechnical monitoring * borehole–wall imaging * structural mapping * rock mass fracturing Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 1.877, year: 2015 http://www.nrcresearchpress.com/doi/pdf/10.1139/cgj-2014-0377

Geochemistry of serpentinites in subduction zones: A review

Science.gov (United States)

Deschamps, Fabien; Godard, Marguerite; Guillot, Stéphane; Hattori, Kéiko

2013-04-01

Over the last decades, numerous studies have emphasized the role of serpentinites in the subduction zones geodynamics. Their presence and effective role in this environment is acknowledged notably by geophysical, geochemical and field observations of (paleo-) subduction zones. In this context, with the increasing amount of studies concerning serpentinites in subduction environments, a huge geochemical database was created. Here, we present a review of the geochemistry of serpentinites, based on the compilation of ~ 900 geochemical analyses of abyssal, mantle wedge and subducted serpentinites. The aim was to better understand the geochemical evolution of these rocks during their subduction history as well as their impact in the global geochemical cycle. When studying serpentinites, it is often a challenge to determine the nature of the protolith and their geological history before serpentinisation. The present-day (increasing) geochemical database for serpentinites indicates little to no mobility of incompatible elements at the scale of the hand-sample in most serpentinized peridotites. Thus, Rare Earth Elements (REE) distribution can be used to identify the initial protolith for abyssal and mantle wedge serpentinites, as well as magmatic processes such as melt/rock interactions taking place before serpentinisation. In the case of subducted serpentinites, the interpretation of trace element data is more difficult due to secondary enrichments independent of the nature of the protolith, notably in (L)REE. We propose that these enrichments reflect complex interactions probably not related to serpentinisation itself, but mostly to fluid/rock or sediment/rock interactions within the subduction channel, as well as intrinsic feature of the mantle protolith which could derive from the continental lithosphere exhumed at the ocean-continent transition. Additionally, during the last ten years, numerous studies have been carried out, notably using in situ approaches, to better

Petrology, mineralogy and geochemistry of surficial uranium deposits

International Nuclear Information System (INIS)

Pagel, M.

1984-01-01

A comprehensive understanding of the petrology, mineralogy, and geochemistry of surficial uranium ore deposits is important for developing prospecting and evaluation strategies. Carnotite is the main uranium mineral and is found in those deposits that have the greatest potential uranium resources. The following uranium-bearing minerals have been reported to occur in surficial deposits: carnotite, tyuyamunite, soddyite, weeksite, haiweeite, uranophane, betauranophane, metaankoleite, torbernite, autunite, phosphuranylite, schroeckingerite, Pb-V-U hydroxide (unnamed mineral), uraninite and organourano complexes. The interrelationships between some of the minerals of the host rocks (especially the clays) are not well understood. (author)

Application of environmental isotope tracing technology to geothermal geochemistry

International Nuclear Information System (INIS)

Shang Yingnan

2006-01-01

This paper reviews the recent application and development of environmental isotope tracing technology to geothermal geochemistry in the following aspects: gas isotopes (He, C) tracing of warm springs; H, O isotope tracing on the origin and cause of geothermal water, environmental isotope dating of geothermal water, and the advantage of excess parameter of deuterium (d) in geothermal research. The author also suggests that isotope method should combine with other geological methods to expand its advantage. (authors)

Geology and geochemistry of the Atacama Desert.

Science.gov (United States)

Tapia, J; González, R; Townley, B; Oliveros, V; Álvarez, F; Aguilar, G; Menzies, A; Calderón, M

2018-02-14

The Atacama Desert, the driest of its kind on Earth, hosts a number of unique geological and geochemical features that make it unlike any other environment on the planet. Considering its location on the western border of South America, between 17 and 28 °S, its climate has been characterized as arid to hyperarid for at least the past 10 million years. Notably dry climatic conditions of the Atacama Desert have been related to uplift of the Andes and are believed to have played an important role in the development of the most distinctive features of this desert, including: (i) nitrates and iodine deposits in the Central Depression, (ii) secondary enrichment in porphyry copper deposits in the Precordillera, (iii) Li enrichment in salt flats of the Altiplano, and (iv) life in extreme habitats. The geology and physiography of the Atacama Desert have been largely shaped by the convergent margin present since the Mesozoic era. The geochemistry of surface materials is related to rock geochemistry (Co, Cr, Fe, Mn, V, and Zn), salt flats, and evaporite compositions in endorheic basins (As, B, and Li), in addition to anthropogenic activities (Cu, Mo, and Pb). The composition of surface water is highly variable, nonetheless in general it presents a circumneutral pH with higher conductivity and total dissolved solids in brines. Major water constituents, with the exception of HCO 3 - , are generally related to the increase of salinity, and despite the fact that trace elements are not well-documented, surface waters of the Atacama Desert are enriched in As, B, and Li when compared to the average respective concentrations in rivers worldwide.

Integrated application of the database for airborne geophysical survey achievement information

International Nuclear Information System (INIS)

Ji Zengxian; Zhang Junwei

2006-01-01

The paper briefly introduces the database of information for airborne geophysical survey achievements. This database was developed on the platform of Microsoft Windows System with the technical methods of Visual C++ 6.0 and MapGIS. It is an information management system concerning airborne geophysical surveying achievements with perfect functions in graphic display, graphic cutting and output, query of data, printing of documents and reports, maintenance of database, etc. All information of airborne geophysical survey achievements in nuclear industry from 1972 to 2003 was embedded in. Based on regional geological map and Meso-Cenozoic basin map, the detailed statistical information of each airborne survey area, each airborne radioactive anomalous point and high field point can be presented visually by combining geological or basin research result. The successful development of this system will provide a fairly good base and platform for management of archives and data of airborne geophysical survey achievements in nuclear industry. (authors)

Rare earth element mineralogy and geochemistry in a laterite profile from Madagascar

DEFF Research Database (Denmark)

Berger, Alfons; Janots, Emilie; Gnos, Edwin

2014-01-01

. The discovery of this new mineral demonstrates that a natural process exists that that can fractionate REE to such an extent to produce a pure gadolinium end-member mineral. An understanding of such a mechanisms is crucial for the REE geochemistry of low temperature alteration processes as well...

Institute of Geophysics, Planetary Physics, and Signatures

Data.gov (United States)

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

Summaries of physical research in the geosciences

Energy Technology Data Exchange (ETDEWEB)

1986-09-01

The summaries in this document describe the scope of the individual programs and detail the research performed during 1984-1985. The Geosciences Research Program includes research in geology, petrology, geophysics, geochemistry, hydrology, solar-terrestrial relationships, aeronomy, seismology, and natural resource analysis, including their various subdivisions and interdisciplinary areas.

Geochemistry of natural technetium and plutonium

International Nuclear Information System (INIS)

Curtis, D.B.; Cappis, J.H.; Perrin, R.E.; Rokop, D.J.

1987-01-01

Technetium and plutonium in unprocessed nuclear reactor wastes are major concerns with regard to their containment in the geologic environment. Both nuclides have long half-lives; therefore, they will exist long after engineered barriers can be considered reliable. Consequently, strategies for the containment of these two elements depend on their retention in the geologic barrier until they have decayed to innocuous levels. Because these are the rarest elements in nature, there have been few direct observations of their geochemical behavior; predictions concerning their fate in the repository are based on properties that can be observed in the laboratory. The authors are attempting to complement the laboratory work by studying the geochemistry of natural plutonium and technetium. Ratios of anthropogenic to naturally occurring isotopes are discussed

Geochemical and geophysical monitoring activities in Campo de Calatrava Volcanic Field (Spain)

Science.gov (United States)

Luengo-Oroz, Natividad; Villasante-Marcos, Víctor; López-Díaz, Rubén; Calvo, Marta; Albert, Helena; Domínguez Cerdeña, Itahiza

2017-04-01

The Campo de Calatrava Volcanic Field (CCVF) or Spanish Central Volcanic Zone is located in central continental Spain (Ciudad Real province) and covers about 5000 km2. It includes around 240 eruptive centers, mainly monogenetic basaltic cones but also explosive maar structures. According to K-Ar geochronology, its main activity phase occurred during Pliocene and Pleistocene epochs (between 5 and 1.7 Ma) and involved alkaline to ultraalkaline magmas, although an older ultrapotassic phase is dated around 8.7-6.4 Ma. However, some recent works have proposed Holocene ages for some of the volcanic products, opening the possibility of considering the CCVF "active" according to international standards. Responding to this situation, the Instituto Geográfico Nacional (IGN) has initiated geochemical and geophysical monitoring activities in the CCVF. Here, we describe these ongoing efforts and we report results about groundwater geochemistry at several natural highly-gaseous springs in the area (hervideros), as well as soil temperature, CO2 diffuse flux from the soil and electrical self-potential data mapped on a small degassing structure called La Sima. In order to analyze microseismicity or any seismic anomaly in the CCVF, a seismic station has also been installed close to this degassing structure. Physicochemical parameters (temperature, pH, Eh and electric conductivity) were measured in situ in four springs and samples were taken in order to analyze major ions and trace elements. Total composition of dissolved gases and helium isotopic ratios were also determined. To complete soil temperature, self-potential and gas prospections performed in La Sima, soil gases were sampled at the bottom of the structure at a depth of 20 cm. Analysis of the total gas composition found 957400 ppm of CO2. Low values of O2 and N2 were also detected (5600 and 24800 ppm respectively).

Airborne Geophysical/Geological Mineral Inventory CIP Program

National Research Council Canada - National Science Library

1999-01-01

The Airborne-Geophysical/Geological Mineral Inventory project is a special multi-year investment to expand the knowledge base of Alaska's mineral resources and catalyze private-sector mineral development...

Exploring the oceans- The geophysical way

Digital Repository Service at National Institute of Oceanography (India)

Murthy, K.S.R.

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

The geochemistry of high-level waste disposal in granitic rocks

International Nuclear Information System (INIS)

Chapman, N.A.; Sargent, F.P.

1984-01-01

Under the auspices of the cooperative agreement between Euratom and Atomic Energy of Canada Ltd about radioactive waste management and disposal, a joint workshop was held on the topic of the geochemistry of high-level waste disposal in granitic rocks. The report covers (1) waste form leaching, (2) thermodynamics, (3) geochemical models, (4) the role of colloids, (5) sorption phenomena, (6) the linking of flow and geochemical models, (7) microbial activity

Geophysical survey aimed at selecting the radioactive waste repository site (Czech republic

Directory of Open Access Journals (Sweden)

Dušan Dostál

2007-01-01

Full Text Available G IMPULS Praha has been executing a set of geophysical measurements for the Radioactive Waste Repository Authority of the Czech Republic from 2001 (the work continues to be carried out. The measurements are aimed at studying the behaviour of the rock massif, focusing on the Excavation Damaged or Disturbed Zone (EDZ and on selecting an appropriate area for the radioactive material repository site. The geophysical studies use a complex of methods as follows: Airborne geophysical measurement (regional studies, Seismic measurement (detailed studies, G.P.R. (detailed studies, Resistivity tomography (detailed studies, Geoelectric measurement and magnetic survey (stray earth currents. The paper informs about first results and conclusions. The airborne work was executed as a part of the complex study of „GEOBARIERA“ the group and the geophysical measurements of EDZ were executed in co-operation with the Czech Geological Survey.

Learning about hydrothermal volcanic activity by modeling induced geophysical changes

Science.gov (United States)

Currenti, Gilda M.; Napoli, Rosalba

2017-05-01

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

Learning about Hydrothermal Volcanic Activity by Modeling Induced Geophysical Changes

Directory of Open Access Journals (Sweden)

Gilda M. Currenti

2017-05-01

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

The Expanding Marketplace for Applied Geophysics

Science.gov (United States)

Carlson, N.; Sirles, P.

2012-12-01

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

Fifth national outdoor action conference on aquifer restoration, ground water monitoring, and geophysical methods

International Nuclear Information System (INIS)

Anon.

1992-01-01

This book presents papers on technology in ground water sampling, monitoring, and remediation and geophysical techniques. The section on monitoring and remediation covers monitoring case studies, monitoring waste disposal sites, petroleum recovery, techniques in aquifer remediation, mathematical analysis of remedial techniques, vacuum extraction, bioremediation, and monitoring techniques. The section on sampling covers measurement variability, microbial sampling, vadose zone sampling, sampling with hydraulic probes, unusual sampling problems and equipment, and data management. A section on geophysics covers geophysics and site characterization, and geophysics and mining. The focus is on hazardous organic compounds. Individual articles are abstracted separately

Tabletop Models for Electrical and Electromagnetic Geophysics.

Science.gov (United States)

Young, Charles T.

2002-01-01

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

The Nirex Sellafield site investigation: the role of geophysical interpretation

International Nuclear Information System (INIS)

Muir Wood, R.; Woo, G.; MacMillan, G.

1992-01-01

This report reviews the methods by which geophysical data are interpreted, and used to characterize the 3-D geology of a site for potential storage of radioactive waste. The report focuses on the NIREX site investigation at Sellafield, for which geophysical observations provide a significant component of the structural geological understanding. In outlining the basic technical principles of seismic data processing and interpretation, and borehole logging, an attempt has been made to identify errors, uncertainties, and the implicit use of expert judgement. To enhance the reliability of a radiological probabilistic risk assessment, recommendations are proposed for independent use of the primary NIREX geophysical site investigation data in characterizing the site geology. These recommendations include quantitative procedures for undertaking an uncertainty audit using a combination of statistical analysis and expert judgement. (author)

Evaluation of some Geophysical and Physicochemical ...

African Journals Online (AJOL)

PROF HORSFALL

2018-04-18

Apr 18, 2018 ... spill point parallel to the pipeline right of way. A research work carried ... of soils has been known to affect soil physio-chemical properties, which in .... The results of the geophysical analysis from the study area are presented ...

36 CFR 1256.62 - Geological and geophysical information relating to wells.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Geological and geophysical... MATERIALS General Restrictions § 1256.62 Geological and geophysical information relating to wells. (a) In accordance with 5 U.S.C. 552(b)(9), NARA may withhold information in records that relates to geological and...

Geophysical and atmospheric evolution of habitable planets.

Science.gov (United States)

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

2010-01-01

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

Geophysical contribution for Folha Patos (PI, Brazil)

International Nuclear Information System (INIS)

Rodrigues, J.C.; Mota, A.C.; Metelo, M.J.; Vasconcelos, R.M. de

1990-01-01

As a part of PLGB (Brazilian Geologic reconnaissance program), executed in 1986-1989 period by Companhia de Pesquisa de Recursos Minerais - CPRM to the Departamento Nacional da Producao Mineral - DNPM, geophysical studies were carried out in the Patos Quadrangle (SB. 24-Y-C-V). Gravimetric, magnetometric and scintillometric methods were performed over selected profiles, and the interpretation of aerial gamma-spectrometric maps (total, potassium, uranium and thorium channels) were integrated with geologic data. Computer programs Magpoly and Gravpoly were utilized in modelling geophysical surface data. Results of theses studies were auxiliary to the geological mapping of that area, specially in localizing lithological contacts and differentiations, tectonic structures, and revealed the structural compartimentation among crustal segments with distinct metamorphic grades. (author)

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

Science.gov (United States)

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

2012-12-01

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

Gallium and germanium geochemistry during magmatic fractionation and post-magmatic alteration in different types of granitoids: A case study from the Bohemian Massif (Czech Republic)

Czech Academy of Sciences Publication Activity Database

Breiter, Karel; Gardenová, N.; Kanický, V.; Vaculovič, T.

2013-01-01

Roč. 64, č. 3 (2013), s. 171-180 ISSN 1335-0552 R&D Projects: GA ČR GAP210/10/1309 Institutional support: RVO:67985831 Keywords : gallium * geochemistry * germanium * granites * ICP -MS Subject RIV: DD - Geochemistry Impact factor: 0.835, year: 2013

Hedberg Research Conference on Fundamental Controls on Flow in Carbonates: Request for Travel Support for Post-Doctoral Fellows

Energy Technology Data Exchange (ETDEWEB)

Pyrak-Nolte, Laura J. [Purdue Univ., West Lafayette, IN (United States)

2013-04-28

Carbonate reservoirs pose a scientific and engineering challenge to geophysical prediction and monitoring of fluid flow in the subsurface. Difficulties in interpreting hydrological, reservoir and other exploration data arise because carbonates are composed of a hierarchy of geological structures, constituents and processes that span a wide spectrum of length and time scales. What makes this problem particularly challenging is that length scales associated with physical structure and processes are often not discrete, but overlap, preventing the definition of discrete elements at one scale to become the building blocks of the next scale. This is particularly true for carbonates where complicated depositional environments, subsequent post-deposition diagenesis and geochemical interactions result in pores that vary in scale from submicron to centimeters to fractures, variation in fabric composition with fossils, minerals and cement, as well as variations in structural features (e.g., oriented inter- and intra layered - interlaced bedding and/or discontinuous rock units). In addition, this complexity is altered by natural and anthropogenic processes such as changes in stress, fluid content, reactive fluid flow, etc. Thus an accurate geophysical assessment of the flow behavior of carbonate reservoirs requires a fundamental understanding of the interplay of textural and structural features subjected to physical processes that affect and occur on various length and time scales. To address this complexity related to carbonates, a Hedberg conference on “Fundamental Controls on Flow in Carbonates” was held July 8 to 13, 2012, to bring together industry and academic scientists to stimulate innovative ideas that can accelerate research advances related to flow prediction and recovery in carbonate reservoirs. Participants included scientist and engineers from multiple disciplines (such as hydrology, structural geology, geochemistry, reservoir engineering, geophysics

Earth Sciences Division annual report, 1976

International Nuclear Information System (INIS)

Hornady, B.; Duba, A.

1977-01-01

This compilation lists abstracts of papers, internal reports, and talks presented during 1976 at national and international meetings by members of the Earth Sciences Division, Lawrence Livermore Laboratory. Subjects include: coal gasification, gas stimulation, geothermal fields, oil shale retorting, radioactive waste management, geochemistry, geophysics, seismology, explosive phenomenology, and miscellaneous studies

Karst aquifer characterization using geophysical remote sensing of dynamic recharge events

Science.gov (United States)

Grapenthin, R.; Bilek, S. L.; Luhmann, A. J.

2017-12-01

Geophysical monitoring techniques, long used to make significant advances in a wide range of deeper Earth science disciplines, are now being employed to track surficial processes such as landslide, glacier, and river flow. Karst aquifers are another important hydrologic resource that can benefit from geophysical remote sensing, as this monitoring allows for safe, noninvasive karst conduit measurements. Conduit networks are typically poorly constrained, let alone the processes that occur within them. Geophysical monitoring can also provide a regionally integrated analysis to characterize subsurface architecture and to understand the dynamics of flow and recharge processes in karst aquifers. Geophysical signals are likely produced by several processes during recharge events in karst aquifers. For example, pressure pulses occur when water enters conduits that are full of water, and experiments suggest seismic signals result from this process. Furthermore, increasing water pressure in conduits during recharge events increases the load applied to conduit walls, which deforms the surrounding rock to yield measureable surface displacements. Measureable deformation should also occur with mass loading, with subsidence and rebound signals associated with increases and decreases of water mass stored in the aquifer, respectively. Additionally, geophysical signals will likely arise with turbulent flow and pore pressure change in the rock surrounding conduits. Here we present seismic data collected during a pilot study of controlled and natural recharge events in a karst aquifer system near Bear Spring, near Eyota, MN, USA as well as preliminary model results regarding the processes described above. In addition, we will discuss an upcoming field campaign where we will use seismometers, tiltmeters, and GPS instruments to monitor for recharge-induced responses in a FL, USA karst system with existing cave maps, coupling these geophysical observations with hydrologic and

Engineering-geophysical criteria for evaluating the development stages of landslides in loess rocks

Energy Technology Data Exchange (ETDEWEB)

Abdullayev, S K

1981-01-01

As a result of conducting geophysical observations on landslide slopes formed by loess rocks, with their artifical moistening, quantitiative engineering-geophysical criteria were obtained which characterize the basic stages of landslide development. The studies were conducted by surface methods of electrical resistance and seismometry conducted directly in the massif. According to the indicators of moisture content, state of comminution, compactness calculated with the help of geophysical parameters, the stage of preparation and movement of landslides are characterized.

SQUID use for Geophysics: finding billions of dollars

Science.gov (United States)

Foley, Catherine

2014-03-01

Soon after their discovery, Jim Zimmerman saw the potential of using Superconducting Quantum Interference Devices, SQUIDs, for the study of Geophysics and undertook experiments to understand the magnetic phenomena of the Earth. However his early experiments were not successful. Nevertheless up to the early 1980's, some research effort in the use of SQUIDs for geophysics continued and many ideas of how you could use SQUIDs evolved. Their use was not adopted by the mining industry at that time for a range of reasons. The discovery of high temperature superconductors started a reinvigoration in the interest to use SQUIDs for mineral exploration. Several groups around the world worked with mining companies to develop both liquid helium and nitrogen cooled systems. The realisation of the achievable sensitivity that contributed to successful mineral discoveries and delineation led to real financial returns for miners. By the mid 2000's, SQUID systems for geophysics were finally being offered for sale by several start-up companies. This talk will tell the story of SQUID use in geophysics. It will start with the early work of the SQUID pioneers including that of Jim Zimmerman and John Clarke and will also cover the development since the early 1990's up to today of a number of magnetometers and gradiometers that have been successfully commercialised and used to create significant impact in the global resources industry. The talk will also cover some of the critical technical challenges that had to be overcome to succeed. It will focus mostly on magnetically unshielded systems used in the field although some laboratory-based systems will be discussed.

Geophysical investigations in the 100 Areas: Fiscal year 1991 through December 1993

Science.gov (United States)

Mitchell, T. H.

1994-09-01

The geophysical investigations identified in this document were conducted by the Westinghouse Hanford Company (WHC) Surface Geophysics Team, Geophysics Group, between October, 1991 and December, 1993. The investigations supported 100-Area activities for the Resource Conservation and Recovery Act of 1976 (RCRA) and the Comprehensive Environmental Response, Compensations and Liability Act of 1980 (CERCLA). The primary intent of this document is to provide a general map location and the associated document number for investigations that have been conducted as of December, 1993. The results of the individual investigations are not included here. The results of all of these investigations have been previously reported individually in WHC supporting documents. The investigations conducted during Fiscal Year (FY) 1992 are summarized in a single WHC document, WHC-SD-EN-TI-204, Rev. O. A brief summary of some of the successful applications of geophysics in the 100-Areas is included.

East-China Geochemistry Database (ECGD):A New Networking Database for North China Craton

Science.gov (United States)

Wang, X.; Ma, W.

2010-12-01

North China Craton is one of the best natural laboratories that research some Earth Dynamic questions[1]. Scientists made much progress in research on this area, and got vast geochemistry data, which are essential for answering many fundamental questions about the age, composition, structure, and evolution of the East China area. But the geochemical data have long been accessible only through the scientific literature and theses where they have been widely dispersed, making it difficult for the broad Geosciences community to find, access and efficiently use the full range of available data[2]. How to effectively store, manage, share and reuse the existing geochemical data in the North China Craton area? East-China Geochemistry Database(ECGD) is a networking geochemical scientific database system that has been designed based on WebGIS and relational database for the structured storage and retrieval of geochemical data and geological map information. It is integrated the functions of data retrieval, spatial visualization and online analysis. ECGD focus on three areas: 1.Storage and retrieval of geochemical data and geological map information. Research on the characters of geochemical data, including its composing and connecting of each other, we designed a relational database, which based on geochemical relational data model, to store a variety of geological sample information such as sampling locality, age, sample characteristics, reference, major elements, rare earth elements, trace elements and isotope system et al. And a web-based user-friendly interface is provided for constructing queries. 2.Data view. ECGD is committed to online data visualization by different ways, especially to view data in digital map with dynamic way. Because ECGD was integrated WebGIS technology, the query results can be mapped on digital map, which can be zoomed, translation and dot selection. Besides of view and output query results data by html, txt or xls formats, researchers also can

Geophysical applications for oil sand mine tailings management

Energy Technology Data Exchange (ETDEWEB)

Parker, D.; Bauman, P. [WorleyParsons, Calgary, AB (Canada)

2009-07-01

Geophysical techniques are applied throughout a mine's life cycle to facilitate siting, constructing and monitoring of tailings dumps and ponds. This presentation described 3 case studies from the Athabasca region in northeast Alberta that demonstrated some of the concerns associated with oil sand mine tailings, and the information that geophysical surveys can provide. The objectives of these studies were to determine the lateral and depth extents of elevated conductivities of soil and groundwater that have high salt concentration from the tailings sand pore fluid. Due to high chloride concentrations within the tailings material, salt within the root zone may affect vegetation. A terrain conductivity survey was designed to map the lateral extents of salinity impact, while an electrical resistivity tomography (ERT) survey was used to delineate the tailings sand leachate at depth. The proper management of oil sand tailings facilities is vital to the life cycle of a mine. It was concluded that geophysical techniques can be instrumental in managing several engineering and environmental challenges, from Pleistocene channel mapping, to tailings pond settling characteristics, to reclaiming tailings sands. 1 ref., 7 figs.

Applied geophysics for civil engineering and mining engineering. 2. rev. and enlarged ed.

International Nuclear Information System (INIS)

Militzer, H.; Schoen, J.; Stoetzner, U.

1986-01-01

In the process of geological and geotechnical prospecting for the exploration and exploitation of deposits, as well as for engineering structures, the knowledge contributed by geophysics is of significance in order to ensure an objective assessment of geological and geotechnical conditions of a given site, and to promote economic efficiency in the field of civil engineering and mining. For this reason, engineering and mining geophysics has become an important special subject field. The present second edition of the textbook offers enhanced information about practical applications of available methods and measuring techniques, and about the information to be obtained by civil and mining engineers from the geophysical science. The material has been arranged with a view to practice, facilitating an overview over potential applications and efficiencies as well as limits of geophysical methods. The methods are also explained in terms of suitability for the various steps of civil engineering or mining geological activities and studies. A major extension of the first edition's material consists of the chapter on basic principles and aspects of well geophysics for shallow well drilling. (orig./HP) [de

Au-bearing magnetite mineralizaion in Kashmar (alteration, mineralization, geochemistry, geochemistry and fluid inclusions;

Directory of Open Access Journals (Sweden)

Alireza Almasi

2017-02-01

Full Text Available Introduction The study area is located in the central part of the Khaf- Kashmar- Bardaskan volcano-plotunic belt (briefly KKBB. Several IOCG deposits such as Tanourjeh Au-bearing magnetite deposit and Kuh-e-Zar Specularite-rich Au deposit have been explored in KKBB. Geology, alteration, mineralization, geochemistry and fluid inclusion results in Kashmar suggest the IOCG type Au-bearing magnetite mineralization. These IOCG deposits at KKBB form at an active continental arc related to SSZ-type Sabzevar oceanic subduction. Materials and methods Use of Landsat 7+, IRS and Aster satellites. Petrography and alteration Studies in 150 thin sections of volcanic and intrusive rocks. Sampling of ore-bearing quartz vein and mineralography. Preparation of 28 geochemistry samples by the chip composite method of ore-bearing quartz vein and analyzing them in the ACME laboratory by Aqua Regia 1DX1. Fluid inclusions studies of 14 samples of quartz and barite related to the ore minerals of ore-bearing quartz vein by THM600 stage of Linkam company. Results Magmatic events in Kashmar occur at Paleocene-Eocene and include: (1 old mafic - intermediate volcano-plutonic series; (2 felsic volcanic and granitoids; and (3 parallel swarm dykes which are youngest (Almasi et al., 2016. Geochemically, Kashmar rocks are metaluminous to highly peraluminous and Tholeitic to calc-alkaline and shoshonitic in composition (Almasi et al., 2016. The field characteristics, together with isotope and geochemical analyses show that all rock types are essentially co-magmatic and post-collisional I-type (Almasi et al., 2016. Alteration of Kashmar is described in two ways: (1 intense ellipsoidal-linear Argillic-Sillicification and low sericitic with Silica caps and with medium widespread and propylitic alterations in triple regions, next to Dorouneh fault; and (2 Medium Hematite-Carbonate-Chlorite-Silicification alterations in Kamarmard heights. In parts of near the Doruneh fault, sometimes

Borehole geophysics in nuclear power plant siting

International Nuclear Information System (INIS)

Crosby, J.W.; Scott, J.D.

1979-01-01

Miniaturized borehole geophysical equipment designed for use in ground-water investigations can be adapted to investigations of nuclear power plant sites. This equipment has proved to be of value in preliminary and comprehensive studies of interior basins where thick sequences of Quaternary clastic sediment, occasionally with associated volcanic rocks, pose problems of stratigraphic correlation. The unconsolidated nature of the deposits generally requires that exploratory holes be cased, which ordinarily restricts the borehole geophysical studies to the radiation functions--natural gamma, gamma-gamma, neutron-gamma, and neutron-epithermal neutron logs. Although a single log response may be dominant in a given area, correlations derive from consideration of all log responses as a composite group. Because major correlations usually are based upon subtle differences in the physical properties of the penetrated sediment, high-resolution logging procedures are employed with some sacrifice of the quantitative parameters important to petroleum technology. All geophysical field data are recorded as hard copy and as digital information on punched paper tape. Digital data are subsequently computer processed and plotted to scales that enhance the stratigraphic data being correlated. Retention of the data in analog format permits rapid review, whereas computer plotting allows playback and detailed examination of log sections and sequences that may be attenuated on hard copy because of the logarithmic nature of the response to the physical property being examined

Re–Os geochemistry and geochronology of the Ransko gabbro–peridotite massif, Bohemian Massif

Czech Academy of Sciences Publication Activity Database

Ackerman, Lukáš; Pašava, J.; Erban, V.

2013-01-01

Roč. 48, č. 7 (2013), s. 799-804 ISSN 0026-4598 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : Re–Os * geochronology * gabbro * Bohemian Massif * Ni–Cu mineralization Subject RIV: DD - Geochemistry Impact factor: 2.667, year: 2013

A geomechanical model of a sinkhole formation

Science.gov (United States)

Danchiv, Alexandru; Zamfirescu, Florian; Mocuta, Marius; Popa, Iulian; Zlibut, Alexandru; Huggenberger, Peter; Zechner, Eric; Dresmann, Horst; Scheidler, Stefan; Wiesmeier, Stefan

2016-04-01

On December 2010 a sinkhole was suddenly formed close to the eastern flank of Ocna-Mures salt dome. Soon after the collapse the sinkhole was filled with brine forming a salt lake called Plus Lake. The total volume of sinkhole of about 100000 m3 remained constant since February 2011. The Ocna Mures salt dome is situated on the western border of the Transylvanian basin (Romania) and has been exploited for a long time. The ceilings of some shallow mine chambers are now collapsed and filled with brine. Along the eastern flank of the salt dome there is a disturbed zone due to diapirism. Its presence is suggested by the strong fragmentation of rock in the boreholes drilled along the salt-sterile contact, as it resulted from the low values of RQD index. The sinkhole is probably due to a pressure increase along the diapir flank. The causes of this sudden increase of pressure are not well known. Most probably it is due to the damage of the tubing of a flank borehole as mentioned in a technical report of the exploiting company. The injected fresh water expelled through the breaches of the damaged borehole and, due to the high pressure flushed up the crushed material of the disturbed zone. In order to better understand the setting up of the Plus Lake joint research efforts were performed by teams from Bucharest and Basel Universities since 2013. For the geomechanical approach a numerical model was performed using the Flac 7.0 code. In a first stage the creep behavior of salt was analyzed considering a Norton creep law. It resulted that after 100 years the salt reached equilibrium, the creep could be neglected and in a first approximation mechanical equilibrium could be analyzed considering only an elasto-plastic behavior of both the salt and the sterile. For both the salt and the surrounding sedimentary rocks the Mohr-Coulomb criterion was considered. The properties of sterile rocks were estimated following the GSI system. Due to poor rock quality the strength parameters have

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

Science.gov (United States)

2014-09-01

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

Development of nuclear physics and its connections to borehole geophysics

International Nuclear Information System (INIS)

Loetzsch, W.

1990-01-01

Starting from the discovery of radioactivity, the development of nuclear physics and its close connections to geoscience, especially to borehole geophysics, are outlined. The discovery of a nuclear physical phenomenon is always followed by an examination for its applications in nuclear geophysics, which since about 1960 has developed into a special discipline of applied geophysics. As an example for this development in the GDR the application of neutron capture γ-ray spectroscopy for iron ore exploration is described. A table listing important present-day nuclear well logging techniques with detectable elements and their detection limits is presented. Examples of measurements with some of these logging techniques reveal their particularities and show their element-specific character and the nuclear physical mechanisms involved. Finally the state of art of nuclear well logging and prospects in this field are outlined. (author)

Airborne geophysics in Australia: the government contribution

International Nuclear Information System (INIS)

Denham, D.

1997-01-01

Airborne geophysical data sets provide important cost-effective information for resource exploration and land management. Improved techniques, developed recently, now enable high-resolution aeromagnetic and gamma-ray surveys to be used extensively by the resource industries to improve the cost effectiveness of exploration and by governments to encourage resource development and sustainable management of natural resources. Although airborne geophysical techniques have been used extensively and are now used almost routinely by mineral explorers, it is only in the last few years that governments have been involved as major players in the acquisition of data. The exploration industry pioneered the imaging of high-resolution airborne geophysical data sets in the early 1980s and, at the same time, the Northern Territory Government started a modest program of flying the Northern Territory, at 500 m flight-line spacing, to attract mineral exploration. After the start of the National Geoscience Mapping Accord in 1990, the then BMR and its State/Territory counterparts used the new high-resolution data as an essential ingredient to underpin mapping programs. These new data sets proved so valuable that, starting in 1992/93, the annual expenditure by the Commonwealth and States/Northern Territory increased from roughly $2 million per year to a massive $10 million per year. These investments by governments, although unlikely to be permanently sustainable, have been made to encourage and expand exploration activity by providing new high-quality data sets in industry at very low cost. There are now approximately 11 million line-km of airborne geophysical data available in databases held by the Commonwealth, States and Northern Territory. The results so far have seen a significant increase in exploration activity in States that have embarked on this course (e.g. South Australia and Victoria), and the information provided from these surveys is proving crucial to understanding the

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

Data.gov (United States)

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

The Medical Geochemistry of Dusts, Soils, and Other Earth Materials

Science.gov (United States)

Plumlee, G. S.; Ziegler, T. L.

2003-12-01

"Town clenched in suffocating grip of asbestos"USA Today, article on Libby,Montana, February, 2000"Researchers find volcanoes are bad for your health… long after they finish erupting"University of WarwickPress Release, 1999"Toxic soils plague city - arsenic, lead in 5 neighborhoods could imperil 17,000 residents"Denver Post, 2002"Ill winds - dust storms ferry toxic agents between countries and even continents"Science News, 2002A quick scan of newspapers, television, science magazines, or the internet on any given day has a fairly high likelihood of encountering a story (usually accompanied by a creative headline such as those above) regarding human health concerns linked to dusts, soils, or other earth materials. Many such concerns have been recognized and studied for decades, but new concerns arise regularly.Earth scientists have played significant roles in helping the medical community understand some important links between earth materials and human health, such as the role of asbestos mineralogy in disease (Skinner et al., 1988; Ross, 1999; Holland and Smith, 2001), and the role of dusts generated by the 1994 Northridge, California, earthquake in an outbreak of Valley Fever ( Jibson et al., 1998; Schneider et al., 1997).Earth science activities tied to health issues are growing (Skinner and Berger, 2003), and are commonly classified under the emerging discipline of medical geology (Finkelman et al., 2001; Selinus and Frank, 2000; Selinus, in press).Medical geochemistry (also referred to as environmental geochemistry and health: Smith and Huyck (1999), Appleton et al. (1996)) can be considered as a diverse subdiscipline of medical geology that deals with human and animal health in the context of the Earth's geochemical cycle ( Figure 1). Many medical geochemistry studies have focused on how chemical elements in rocks, soils, and sediments are transmitted via water or vegetation into the food chain, and how regional geochemical variations can result in disease

The role of the geophysical template and environmental regimes in controlling stream-living trout populations

Science.gov (United States)

Penaluna, Brooke E.; Railsback, Steve F.; Dunham, Jason B.; Johnson, S.; Bilby, Richard E.; Skaugset, Arne E.

2015-01-01

The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams.

Preparation of peat samples for inorganic geochemistry used as palaeoenvironmental proxies

Directory of Open Access Journals (Sweden)

G. Le Roux

2010-07-01

Full Text Available This article provides a brief review of protocols used in peat inorganic geochemistry. We emphasise the key issues that could lead to inter-comparison problems. For each section (drying, grinding, non-destructive analyses, acid digestions and destructive analyses, recommendations are provided to guide the reader through an idealised protocol, which is the only workable approach for studies incorporating long-term comparisons.

EXPLORATION BY MEANS OF GEOPHYSICAL METHODS OF GEOTHERMAL FIELDS AND CASE STUDIES

Directory of Open Access Journals (Sweden)

Züheyr KAMACI

1997-01-01

Full Text Available Geothermal energy which is one of the reuseable energy resources, can save as much as 77 million barrels of petroleum equivalent annually when used in the production of electricity and heating-environment. Geophysical exploration methods plays in important role in the fields of geothermal exploration, development and observational studies. Thermal and geoelectrical methods are the most effective methods which shows the temperature variation anomalies and mechanical drilling places. But, when the other methods of gravity, magnetic, radiometric, well geophysics and well logs can be used in conjunction with seismic tomography, apart from the mentioned geophysical exploration method, better results could be obtained. From the above mentioned facts various case history reports are given from our country and worldwide to determine geothermal energy resources by using geophysical exploration technique application. From these results of studies a 55 °C hot water artessian aquifer is found in the Uşak-Banaz geothermal field by applying geoelectrical methods.

Pollution distribution in floodplain structure visualised by electrical resistivity imaging in the floodplain of the Litavka River, the Czech Republic

Czech Academy of Sciences Publication Activity Database

Faměra, Martin; Kotková, Kristýna; Tůmová, Štěpánka; Elznicová, J.; Matys Grygar, Tomáš

2018-01-01

Roč. 165, JUN (2018), s. 157-172 ISSN 0341-8162 R&D Projects: GA ČR(CZ) GA15-00340S Institutional support: RVO:61388980 Keywords : Electric resistivity * Floodplain structure * Geophysical methods * Pollution chemostratigraphy * Post-depositional migration * Shallow subsurface Subject RIV: DD - Geochemistry OBOR OECD: Geology Impact factor: 3.191, year: 2016

A Bayesian trans-dimensional approach for the fusion of multiple geophysical datasets

Science.gov (United States)

JafarGandomi, Arash; Binley, Andrew

2013-09-01

We propose a Bayesian fusion approach to integrate multiple geophysical datasets with different coverage and sensitivity. The fusion strategy is based on the capability of various geophysical methods to provide enough resolution to identify either subsurface material parameters or subsurface structure, or both. We focus on electrical resistivity as the target material parameter and electrical resistivity tomography (ERT), electromagnetic induction (EMI), and ground penetrating radar (GPR) as the set of geophysical methods. However, extending the approach to different sets of geophysical parameters and methods is straightforward. Different geophysical datasets are entered into a trans-dimensional Markov chain Monte Carlo (McMC) search-based joint inversion algorithm. The trans-dimensional property of the McMC algorithm allows dynamic parameterisation of the model space, which in turn helps to avoid bias of the post-inversion results towards a particular model. Given that we are attempting to develop an approach that has practical potential, we discretize the subsurface into an array of one-dimensional earth-models. Accordingly, the ERT data that are collected by using two-dimensional acquisition geometry are re-casted to a set of equivalent vertical electric soundings. Different data are inverted either individually or jointly to estimate one-dimensional subsurface models at discrete locations. We use Shannon's information measure to quantify the information obtained from the inversion of different combinations of geophysical datasets. Information from multiple methods is brought together via introducing joint likelihood function and/or constraining the prior information. A Bayesian maximum entropy approach is used for spatial fusion of spatially dispersed estimated one-dimensional models and mapping of the target parameter. We illustrate the approach with a synthetic dataset and then apply it to a field dataset. We show that the proposed fusion strategy is

The lithospheric structure beneath Ireland and surrounding areas from integrated geophysical-petrological modelling of magnetic and other geophysical data

Science.gov (United States)

Baykiev, E.; Guerri, M.; Fullea, J.

2017-12-01

The availability of unprecedented resolution aeromagnetic data in Ireland (Tellus project, http://www.tellus.ie/) in conjunction with new satellite magnetic data (e.g., ESÁs Swarm mission) has opened the possibility of detailed modelling of the Irish subsurface magnetic structure. A detailed knowledge of the magnetic characteristics (susceptibility, magnetite content) of the crust is relevant for a number of purposes, including geological mapping and mineral and geothermal energy prospection. In this work we model the magnetic structure of Ireland and surrounding areas using primarily aeromagnetic and satellite observations but also other geophysical data sets. To this aim we use a geophysical-petrological modelling tool (LitMod) in which key properties of rocks (i.e., density, electrical conductivity and seismic velocities) that can be inferred from geophysical data (gravity, seismic, EM) are self consistently determined based on the thermochemical conditions (using the software Perple_X). In contrast to the mantle, where thermodynamic equilibrium is prevalent, in the crust metastable conditions are dominant, i.e. rock properties may not be representative of the current, in situ, temperature and pressure conditions. Instead, the rock properties inferred from geophysical data may be reflecting the mineralogy stable at rock formation conditions. In addition, temperature plays a major role in the distribution of the long wavelength crustal magnetic anomalies. Magnetite retains its magnetic properties below its Curie temperature (585 ºC) and the depth of Curie's isotherm provides an estimate of the thickness of the magnetic crust. Hence, a precise knowledge of the crustal geotherm is required to consistently model crustal magnetic anomalies. In this work LitMod has been modified to account for metastable crustal lithology, to predict susceptibility in the areas below Curie's temperature, and to compute magnetic anomalies based on a magnetic tesseroid approach. The

A conceptual hydrogeologic model for the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

Science.gov (United States)

Thomas, Jonathan V.; Stanton, Gregory P.; Bumgarner, Johnathan R.; Pearson, Daniel K.; Teeple, Andrew; Houston, Natalie A.; Payne, Jason; Musgrove, MaryLynn

2013-01-01

The Edwards-Trinity aquifer is a vital groundwater resource for agricultural, industrial, and municipal uses in the Trans-Pecos region of west Texas. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system in the 4,700 square-mile study area was developed by the U.S. Geological Survey (USGS) in cooperation with the Middle Pecos Groundwater Conservation District, Pecos County, City of Fort Stockton, Brewster County, and Pecos County Water Control and Improvement District No. 1. The model was developed to gain a better understanding of the groundwater system and to establish a scientific foundation for resource-management decisions. Data and information were collected or obtained from various sources to develop the model. Lithologic information obtained from well reports and geophysical data were used to describe the hydrostratigraphy and structural features of the groundwater system, and aquifer-test data were used to estimate aquifer hydraulic properties. Groundwater-quality data were used to evaluate groundwater-flow paths, water and rock interaction, aquifer interaction, and the mixing of water from different sources. Groundwater-level data also were used to evaluate aquifer interaction as well as to develop a potentiometric-surface map, delineate regional groundwater divides, and describe regional groundwater-flow paths.

rights reserved Geophysical Identification of Hydrothermally Altered

African Journals Online (AJOL)

ADOWIE PERE

Geophysical Identification of Hydrothermally Altered Structures That Favour .... aircraft. Total line kilometers of 36,500 were covered in the survey. Magnetic ... tie lines occur at about 2000 metres interval in the ... visual inspection of the map.

The 'glass earth' - geochemical frontiers in exploration through cover

International Nuclear Information System (INIS)

Carr, G.; Denton, G.; Giblin, A.; Korsch, M.; Andrew, A.; Whitford, D.

1999-01-01

'Glass Earth' represents a number of current and planned projects within CSIRO aimed at making 'transparent' the top 1000 m of the Earth's crust It builds upon current technologies developed within a number of CSIRO divisions as well as the Australian Mineral Exploration Technologies CRC (AMET CRC), the Australian Geodynamics CRC (AG CRC) and the CRC for Landscape Evolution and Mineral Exploration (CRC LEME). New geophysical and geochemical technologies will be developed to complement these, together with new capabilities in modelling, data integration and visualisation, including hydrogeochemistry, hydrogeology, surface geochemistry and isotope geochemistry, modelling of chemical, fluid and heat flows in rock and regolith, advanced visualisation and data fusion. This paper describes some recent work in the field of isotope geochemistry, with the principal aim of 'seeing through' cover to understand basement geology and detect hidden ore systems

Smartphones - the Geophysics Lab in Your Students' Pocket

Science.gov (United States)

Salaree, A.; Stein, S.; Saloor, N.; Elling, R. P.

2017-12-01

Many interesting topics are hard to demonstrate in geophysics classes without costly equipment and logistic hassles. For instance, the speed of P-waves in the Earth's crust is usually calculated using printed seismic sections from published studies, giving students little insight into the recording process. This is mainly due to the complex, costly, and weather-dependent logistics of conducting seismic reflection experiments using arrays of - either purchased or borrowed - expensive seismometers and recording units. Smartphones, which students own and are (perhaps unduly) comfortable with, have many otherwise expensive instruments as built-in sensors. These instruments are nifty tools that make labs easier, faster, and more fun. We use smartphones in several labs in an introductory geophysics class. In one, students use their phones to measure the latitude and longitude of a point on campus. Combining the data shows a nice spread of positions illustrating the precision of measurements, spatial trends in the scatter, and even differences between Android and iPhone data. Hence concepts about data that are often presented with ideal theoretical examples emerge from the students' measurements. Another uses the phones' accelerometers and available software to measure the speed of P-waves using a linear array of smartphones/seismometers along a table, similar to the procedure used in reflection seismology. In a third, students used their smartphones in an elevator to measure the acceleration of gravity in a moving reference frame, and thus explore key concepts that arise in many geophysical applications. These three applications illustrate the potential for using smartphones in a wide variety of geophysics teaching, much as their value is being increasingly recognized in other educational applications. Here are some links to an instructions document and a video from the seismic experiment: Instructions: http://www.earth.northwestern.edu/ amir/202/smartphone

WLS software for the Los Alamos geophysical instrumentation truck

International Nuclear Information System (INIS)

Ideker, C.D.; LaDelfe, C.M.

1985-01-01

Los Alamos National Laboratory's capabilities for special downhole geophysical well logging has increased steadily over the past few years. Software was developed originally for each individual tool as it became operational. With little or no standardization for tool software modules, software development became redundant, time consuming, and cost ineffective. With long-term use and the rapid evolution of well logging capacity in mind. Los Alamos and EG and G personnel decided to purchase a software system. The system was designed to offer: wide-range use and programming flexibility; standardization subroutines for tool module development; user friendly operation which would reduce training time; operator error checking and alarm activation; maximum growth capacity for new tools as they are added to the inventory; and the ability to incorporate changes made to the computer operating system and hardware. The end result is a sophisticated and flexible software tool and for transferring downhole geophysical measurement data to computer disk files. This paper outlines the need, design, development, and implementation of the WLS software for geophysical data acquisition. A demonstration and working examples are included in the presentation

Integrated geophysical surveys for searching of podiform chromite in Albania

Energy Technology Data Exchange (ETDEWEB)

Kospiri, Aleksander; Zajmi, Asim [Geophysical and Geochemical Center, Tirana (Albania)

1995-12-31

The purpose of this paper is to describe the application of geophysical methods to the search for chromite in Albania. Albania is well known for its chromite resources and ranks third amongst world producers of high-quality chromite. The ultramafic massif of Bulqiza, is the most important chromite bearing one. Surveying a surface of about 120 square kilometers (30% of massifs area) in that massif with integrated geophysical methods a considerable number of targets has been discovered, from which some are already objects under mine activity. In the integrated methods for chromite exploration in Bulqiza ultramafic massif are included: geological, gravity, magnetic and electrical mapping of the scale 1:2000 with survey grids 40x20m, 20x5m. Based on the interpretations of geophysical exploration were projected drilling which led to the discovery of some big ore deposits. (author). 12 refs., 3 figs

76 FR 68720 - Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Geophysical Survey...

Science.gov (United States)

2011-11-07

... Marine Mammals Incidental to Specified Activities; Low- Energy Marine Geophysical Survey in the Western... conducting a low-energy marine geophysical (i.e., seismic) survey in the western tropical Pacific Ocean... Science Foundation (NSF), and ``Environmental Assessment of a Low-Energy Marine Geophysical Survey by the...

Geophysical analysis for the Ada Tepe region (Bulgaria) - case study

Science.gov (United States)

Trifonova, Petya; Metodiev, Metodi; Solakov, Dimcho; Simeonova, Stela; Vatseva, Rumiana

2013-04-01

According to the current archeological investigations Ada Tepe is the oldest gold mine in Europe with Late Bronze and Early Iron age. It is a typical low-sulfidation epithermal gold deposit and is hosted in Maastrichtian-Paleocene sedimentary rocks above a detachment fault contact with underlying Paleozoic metamorphic rocks. Ada Tepe (25o.39'E; 41o.25'N) is located in the Eastern Rhodope unit. The region is highly segmented despite the low altitude (470-750 m) due to widespread volcanic and sediment rocks susceptible to torrential erosion during the cold season. Besides the thorough geological exploration focused on identifying cost-effective stocks of mineral resources, a detailed geophysical analysis concernig diferent stages of the gold extraction project was accomplished. We present the main results from the geophysical investigation aimed to clarify the complex seismotectonic setting of the Ada Tepe site region. The overall study methodology consists of collecting, reviewing and estimating geophysical and seismological information to constrain the model used for seismic hazard assessment of the area. Geophysical information used in the present work consists of gravity, geomagnetic and seismological data. Interpretation of gravity data is applied to outline the axes of steep gravity transitions marked as potential axes of faults, flexures and other structures of dislocation. Direct inverse techniques are also utilized to estimate the form and depth of anomalous sources. For the purposes of seismological investigation of the Ada Tepe site region an earthquake catalogue is compiled for the time period 510BC - 2011AD. Statistical parameters of seismicity - annual seismic rate parameter, ?, and the b-value of the Gutenberg-Richter exponential relation for Ada Tepe site region, are estimated. All geophysical datasets and derived results are integrated using GIS techniques ensuring interoperability of data when combining, processing and visualizing obtained

Simulation of Water Chemistry using and Geochemistry Code, PHREEQE

Energy Technology Data Exchange (ETDEWEB)

Chi, J.H. [Korea Electric Power Research Institute, Taejeon (Korea)

2001-07-01

This report introduces principles and procedures of simulation for water chemistry using a geochemistry code, PHREEQE. As and example of the application of this code, we described the simulation procedure for titration of an aquatic sample with strong acid to investigate the state of Carbonates in aquatic solution. Major contents of this report are as follows; Concepts and principles of PHREEQE, Kinds of chemical reactions which may be properly simulated by PHREEQE, The definition and meaning of each input data, An example of simulation using PHREEQE. (author). 2 figs., 1 tab.

Mathematics applied to nuclear geophysics

International Nuclear Information System (INIS)

Pereira, E.B.; Nordemann, D.J.R.

1987-01-01

One of the powerful auxiliary to nuclear geophysics is the obtention and interpretation of the alpha and gamma radiation spectra. This work discuss, qualitative and quantitative, the lost information problem, motivated by the noise in the process of information codification. The decodification process must be suppield by the appropriate mathematical model on the measure system to recovery the information from nuclear source. (C.D.G.) [pt

Conceptual Design of Geophysical Microsatellite

Directory of Open Access Journals (Sweden)

Matviyenko, S.A.

2014-10-01

Full Text Available The article covers the issue of Earth gravitational field (EGF parameters measurement from space. The radiophysical method of measurement of gravitational frequency shift of electromagnetic radiation using existent GNSS and its two variants are developed by the author. The designlayout drawing of geophysical microsatellite, which implements the radiophysical method of EGF measurement and provides Earth plasmasphere and magnetosphere monitoring, is offered.

Results of integrated geophysical measurements on a landslide endangered brown coal dump

Energy Technology Data Exchange (ETDEWEB)

Militzer, H; Lindner, H; Kaeppler, R

1984-01-01

The measurements revealed occurrence of geophysical anomalies across artificial soils with low content of cohesive material. The proven anomalies varied with time with regard to their magnitude and position. Possible relations between the temporal variations of the geophysical fields and a landslide on the boundary of the object are discussed.

Solid state nuclear track detection: a useful geological/geophysical tool

International Nuclear Information System (INIS)

Khan, H.A.; Qureshi, A.A.

1994-01-01

Solid State Nuclear Track Detection (SSNTD) is a relatively new nuclear particle detection technique. Since its inception, it has found useful application in almost every branch of science. This paper gives a very brief review of the role it has played in solving some geological/geophysical problems. Since the technique has been found useful in a wide spectrum of geological/geophysical applications, it was simply not possible to discuss all of these in this paper due to severe space restrictions. However, an attempt has been made to discuss the salient features of some of the most prominent applications in the geological and geophysical sciences. The paper has been divided into two parts. Firstly, applications based on radon measurements by SSNTDs have been described. These include: Uranium/thorium and mineral exploration, search for geothermal energy sources, study of volcanic processes, location of geological faults and earthquake prediction, for example. Secondly, applications based on the study of spontaneous fission tracks in geological samples have been described briefly. The second group of applications includes: fission track dating (FTD) of geological samples, FTD in the study of emplacement times, provenance studies, and thermal histories of minerals. Necessary references have been provided for detailed studies of (a) the applications cited in this paper, and (b) other important geological/geophysical applications, which unfortunately could not be covered in the present paper. (author)

A geological and geophysical data collection system

Digital Repository Service at National Institute of Oceanography (India)

Sudhakar, T.; Afzulpurkar, S.

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

Geophysics Under Pressure: Large-Volume Presses Versus the Diamond-Anvil Cell

Science.gov (United States)

Hazen, R. M.

2002-05-01

Prior to 1970, the legacy of Harvard physicist Percy Bridgman dominated high-pressure geophysics. Massive presses with large-volume devices, including piston-cylinder, opposed-anvil, and multi-anvil configurations, were widely used in both science and industry to achieve a range of crustal and upper mantle temperatures and pressures. George Kennedy of UCLA was a particularly influential advocate of large-volume apparatus for geophysical research prior to his death in 1980. The high-pressure scene began to change in 1959 with the invention of the diamond-anvil cell, which was designed simultaneously and independently by John Jamieson at the University of Chicago and Alvin Van Valkenburg at the National Bureau of Standards in Washington, DC. The compact, inexpensive diamond cell achieved record static pressures and had the advantage of optical access to the high-pressure environment. Nevertheless, members of the geophysical community, who favored the substantial sample volumes, geothermally relevant temperature range, and satisfying bulk of large-volume presses, initially viewed the diamond cell with indifference or even contempt. Several factors led to a gradual shift in emphasis from large-volume presses to diamond-anvil cells in geophysical research during the 1960s and 1970s. These factors include (1) their relatively low cost at time of fiscal restraint, (2) Alvin Van Valkenburg's new position as a Program Director at the National Science Foundation in 1964 (when George Kennedy's proposal for a Nation High-Pressure Laboratory was rejected), (3) the development of lasers and micro-analytical spectroscopic techniques suitable for analyzing samples in a diamond cell, and (4) the attainment of record pressures (e.g., 100 GPa in 1975 by Mao and Bell at the Geophysical Laboratory). Today, a more balanced collaborative approach has been adopted by the geophysics and mineral physics community. Many high-pressure laboratories operate a new generation of less expensive

Practices to enable the geophysical research spectrum: from fundamentals to applications

Science.gov (United States)

Kang, S.; Cockett, R.; Heagy, L. J.; Oldenburg, D.

2016-12-01

In a geophysical survey, a source injects energy into the earth and a response is measured. These physical systems are governed by partial differential equations and their numerical solutions are obtained by discretizing the earth. Geophysical simulations and inversions are tools for understanding physical responses and constructing models of the subsurface given a finite amount of data. SimPEG (http://simpeg.xyz) is our effort to synthesize geophysical forward and inverse methodologies into a consistent framework. The primary focus of our initial development has been on the electromagnetics (EM) package, with recent extensions to magnetotelluric, direct current (DC), and induced polarization. Across these methods, and applied geophysics in general, we require tools to explore and build an understanding of the physics (behaviour of fields, fluxes), and work with data to produce models through reproducible inversions. If we consider DC or EM experiments, with the aim of understanding responses from subsurface conductors, we require resources that provide multiple "entry points" into the geophysical problem. To understand the physical responses and measured data, we must simulate the physical system and visualize electric fields, currents, and charges. Performing an inversion requires that many moving pieces be brought together: simulation, physics, linear algebra, data processing, optimization, etc. Each component must be trusted, accessible to interrogation and manipulation, and readily combined in order to enable investigation into inversion methodologies. To support such research, we not only require "entry points" into the software, but also extensibility to new situations. In our development of SimPEG, we have sought to use leading practices in software development with the aim of supporting and promoting collaborations across a spectrum of geophysical research: from fundamentals to applications. Designing software to enable this spectrum puts unique

Proceedings of 1. international symposium on applied isotope geochemistry (AIG-1)

International Nuclear Information System (INIS)

Aaberg, G.; Joergensen, E.B.

1993-09-01

The publication is a compilation of abstracts from the ''1. international symposium on applied isotope geochemistry (AIG-1)'' in Norway. The symposium was the first of its kind taking up different applications of most of the available isotopic systems and thus covered a wide range of topics from: 1) Water resources, hydrology, geomedicine and environmental problems, 2) Petroleum exploration and production, 3) Mineral exploration and 4) Analytical methods

Under the pile. Understanding subsurface dynamics of historical cities trough geophysical models interpretation

Science.gov (United States)

Bernardes, Paulo; Pereira, Bruno; Alves, Mafalda; Fontes, Luís; Sousa, Andreia; Martins, Manuela; Magalhães, Fernanda; Pimenta, Mário

2017-04-01

Braga is one of the oldest cities of the Iberian NW and as of so, the research team's studying the city's historical core for the past 40 years is often confronted with the unpredictability factor laying beneath an urban site with such a long construction history. In fact, Braga keeps redesigning its urban structure over itself on for the past 2000 years, leaving us with a research object filled with an impressive set of construction footprints from the various planning decisions that were taken in the city along its historical path. Aiming for a predicting understanding of the subsoil, we have used near surface geophysics as an effort of minimizing the areas of intervention for traditional archaeological survey techniques. The Seminário de Santiago integrated geophysical survey is an example of the difficulties of interpreting geophysical models in very complex subsurface scenarios. This geophysical survey was planned in order to aid the requalification project being designed for this set of historical buildings, that are estimated to date back to the 16h century, and that were built over one of the main urban arteries of both roman and medieval layers of Braga. We have used both GPR as well as ERT methods for the geophysical survey, but for the purpose of this article, we will focus in the use of the ERT alone. For the interpretation of the geophysical models we've cross-referenced the dense knowledge existing over the building's construction phases with the complex geophysical data collected, using mathematical processing and volume-based visualization techniques, resorting to the use of Res2Inv©, Paraview© and Voxler® software's. At the same time we tried to pinpoint the noise caused by the past 30 year's infrastructural interventions regarding the replacement of the building's water and sanitation systems and for which we had no design plants, regardless of its recent occurring. The deep impact of this replacement actions revealed by the archaeological

The relationship of fractals in geophysics to 'the new science'

International Nuclear Information System (INIS)

Turcotte, Donald L.

2004-01-01

Many phenomena in geophysics satisfy fractal statistics, examples range from the frequency-area statistics of earthquakes to the time series of the earth's magnetic field. Solutions to classical differential equations cannot give this type of behavior. Several 'cellular automata' models have successfully reproduced the observed statistics. For example, the slider-block model for earthquakes. Stephen Wolfram's recent book A New Kind of Science sets forth a 'new science' based on cellular automata. This paper discusses the role of cellular automata in geophysics

Yucca Mountain Project: A summary of technical support activities, January 1987--June 1988

International Nuclear Information System (INIS)

1989-05-01

The activities in the Geochemistry and Mineralogy section of our program support three independent and interrelated subject areas which are: Geochemical retardation/transport of radionuclides to the accessible environment, site-specific mineralogy and geophysical studies to establish the hydrogeology of the vadose zone, and past climate and related genesis of authigenic desert carbonates and silicates

A tool for Exploring Geophysical Data: The VGEE-IDV

Science.gov (United States)

Pandya, R. E.; Murray, D.

2002-12-01

The Visual Geophysical Exploration Environment (VGEE) is a suite of computer tools and accompanying online curricular units that enable students to develop physical insight from geophysical data sets. The VGEE curriculum is inquiry and visualization based. The curriculum begins by asking students to compare visualizations they construct from authentic geosciences data to their own conception of the geophysical phenomenon. This comparison encourages students to identify and challenge their own prior conceptions of the phenomenon, a necessary prerequisite to successful learning. Students then begin building correct understandings by identifying patterns and relationships within their visualizations. Students use idealized concept models that highlight physical principles to explain these patterns and relationships. Research, however, has shown that the physical insight gained from these idealized models isn't often applied to either the real world or to the data visualized. To address this, students can easily embed these idealized concept models into their visualizations; there the idealized models respond to the real physical conditions of the geophysical data. The entire inquiry process is built around multi-dimensional and multi-variable visualizations of real geophysical data. Advantages of visualization include its using a natural human talent and its removing mathematics as a barrier to insight. Multi-dimensional and multi-variable visualizations offer the additional advantage of integrated perspectives; rather than asking learners to mentally combine two-dimensional representations of different variables, the learners can navigate through a three-dimensional time-varying representation and get a holistic view. Finally, learner constructed visualizations offer the students a experience with scientific tools, a chance to tailor their investigation to their own misconceptions, and the potential for more robust understanding than prepared visualizations. The

Major Changes in AGU Publication Fees

Science.gov (United States)

Cook, Bill

2010-12-01

Effective with any manuscript submitted after 31 December 2010, AGU is eliminating color charges in all formats. At the same time that we eliminate color charges, we are simplifying publication fees. Articles published in Journal of Geophysical Research; Geochemistry, Geophysics, Geosystems; and Radio Science will each have a flat fee of $1000, and Geophysical Research Letters (GRL) articles will each have a flat fee of $500. These prices represent a small drop from the average cost currently paid by authors. We will retain the excess page charges for full articles longer than 13 pages (including Water Resources Research) and 4 pages for letters, comments, and replies. This simplification means we can streamline the “calculator” authors must use when submitting manuscripts to AGU.

Geochemistry and petrology of pyroxenite xenoliths from Cenozoic alkaline basalts, Bohemian Massif

Czech Academy of Sciences Publication Activity Database

Ackerman, Lukáš; Špaček, Petr; Medaris Jr., G.; Hegner, E.; Svojtka, Martin; Ulrych, Jaromír

2012-01-01

Roč. 57, č. 4 (2012), s. 199-219 ISSN 1802-6222 R&D Projects: GA ČR(CZ) GA205/09/1170 Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z30120515 Institutional support: RVO:67985831 ; RVO:67985530 Keywords : pyroxenite * xenolith * Cenozoic * basalt * Sr-Nd isotopes * geothermobarometry Subject RIV: DD - Geochemistry Impact factor: 0.804, year: 2012

Controlled drilling technology for HLW management. Directional drilling and mechanics/stress measurements in the borehole

International Nuclear Information System (INIS)

Kiho, Kenzo; Shin, Koichi; Okada, Tetsuji; Obuchi, Yasuyoshi; Sunaga, Takayuki; Hase, Kazunori

2013-01-01

Since 2000, Central Research Institute of Electric Power Industry (CRIEPI) has been conducting the project on controlled drilling and the logging/measurement technologies in its boreholes. Especially borehole pressure meter and bore hole stress measurement apparatus which can apply to the controlled drilling system was developed. The bore hole was drilled to the 1000 m long in order to intersect the Omagari fault located at Horonobe town in Hokkaido and its core recovery was 99.8% as of FY. 2011. Using borehole logging/measurement/survey, the geological, hydrological, geo-mechanical, geophysical and geochemical data were collected and the Omagari fault was characterized. (author)

Integrating microsatellite DNA markers and otolith geochemistry to assess population structure of European hake (Merluccius merluccius)

Science.gov (United States)

Tanner, Susanne E.; Pérez, Montse; Presa, Pablo; Thorrold, Simon R.; Cabral, Henrique N.

2014-04-01

Population structure and natal origins of European hake were investigated using microsatellite DNA markers and otolith geochemistry data. Five microsatellites were sequenced and otolith core geochemical composition was determined from age-1 hake collected in the northeast Atlantic Ocean and the Mediterranean Sea. Microsatellites provided evidence of a major genetic split in the vicinity of the Strait of Gibraltar, separating the Atlantic and the Mediterranean populations, with the exception of the Gulf of Cádiz. Based on classification models using otolith core geochemical values, individual natal origins were identified, although with an increased error rate. Coupling genotype and otolith data increased the classification accuracy of individuals to their potential natal origins while providing evidence of movement between the northern and southern stock units in the Atlantic Ocean. Information obtained by the two natural markers on population structure of European hake was complementary as the two markers act at different spatio-temporal scales. Otolith geochemistry provides information over an ecological time frame and on a fine spatial scale, while microsatellite DNA markers report on gene flow over evolutionary time scales and therefore act on a broader spatio-temporal resolution. Thus, this study confirmed the value of otolith geochemistry to complement the assessment of early life stage dispersal in populations with high gene flow and low genetic divergence.

pyGIMLi: An open-source library for modelling and inversion in geophysics

Science.gov (United States)

Rücker, Carsten; Günther, Thomas; Wagner, Florian M.

2017-12-01

Many tasks in applied geosciences cannot be solved by single measurements, but require the integration of geophysical, geotechnical and hydrological methods. Numerical simulation techniques are essential both for planning and interpretation, as well as for the process understanding of modern geophysical methods. These trends encourage open, simple, and modern software architectures aiming at a uniform interface for interdisciplinary and flexible modelling and inversion approaches. We present pyGIMLi (Python Library for Inversion and Modelling in Geophysics), an open-source framework that provides tools for modelling and inversion of various geophysical but also hydrological methods. The modelling component supplies discretization management and the numerical basis for finite-element and finite-volume solvers in 1D, 2D and 3D on arbitrarily structured meshes. The generalized inversion framework solves the minimization problem with a Gauss-Newton algorithm for any physical forward operator and provides opportunities for uncertainty and resolution analyses. More general requirements, such as flexible regularization strategies, time-lapse processing and different sorts of coupling individual methods are provided independently of the actual methods used. The usage of pyGIMLi is first demonstrated by solving the steady-state heat equation, followed by a demonstration of more complex capabilities for the combination of different geophysical data sets. A fully coupled hydrogeophysical inversion of electrical resistivity tomography (ERT) data of a simulated tracer experiment is presented that allows to directly reconstruct the underlying hydraulic conductivity distribution of the aquifer. Another example demonstrates the improvement of jointly inverting ERT and ultrasonic data with respect to saturation by a new approach that incorporates petrophysical relations in the inversion. Potential applications of the presented framework are manifold and include time

Increasing diversity in the geosciences through the AfricaArray geophysics field course

Science.gov (United States)

Vallejo, G.; Emry, E.; Galindo, B. L.; Carranza, V.; Gomez, C. D.; Ortiz, K.; Castro, J. G.; Guandique, J.; Falzone, C.; Webb, S. J.; Manzi, M.; Mngadi, S. B.; Stephens, K.; Chinamora, B.; Whitehead, R.; de Villiers, D. P.; Tshitlho, K.; Delhaye, R. P.; Smith, J. A.; Nyblade, A.

2014-12-01

For the past nine years, the AfricaArray diversity program, sponsored by industry, the National Science Foundation, and several partnering universities have supported outstanding U.S. STEM underrepresented minority undergraduates to gain field experience in near-surface geophysical techniques during an 8-week summer program at Penn State University and the University of Witwatersrand (Wits). The AfricaArray geophysics field school, which is run by Wits, has been teaching field-based geophysics to African students for over a decade. In the first 2-3 weeks of the program, the U.S. students are given basic instruction in near-surface geophysics, South African geology, and South African history and culture. The students then join the Wits AfricaArray geophysics field school - working alongside Wits students and students from several other African universities to map the shallow subsurface in prospective areas of South Africa for platinum mining. In addition to the primary goals of collecting and interpreting gravity, magnetic, resistivity, seismic refraction, seismic reflection, and EM data, students spend time mapping geologic units and gathering information on the physical properties of the rocks in the region (i.e. seismic velocity, density, and magnetic susceptibility). Subsurface targets include mafic dikes, faults, the water table, and overburden thickness. Upon returning to the U.S., students spend 2-3 weeks finalizing their project reports and presentations. The program has been effective at not only providing students with fundamental skills in applied geophysics, but also in fostering multicultural relationships, preparing students for graduate work in the geosciences, and attracting STEM students into the geosciences. Student presenters will discuss their experiences gained through the field school and give their impressions about how the program works towards the goal of increasing diversity in the geosciences in the U.S.

Results from the University of Calgary environmental geophysics test range

Energy Technology Data Exchange (ETDEWEB)

Duckworth, K; Lawton, D.C.; Juigalli, J; Parry, D. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

1995-12-31

The Spy Hill Research Farm, operated by the University of Calgary as a test range site where geophysical equipment and methods related to environmental monitoring can be operated under controlled conditions, was described. The site is used by students in the geophysics courses offered at the University, but it is also intended to be available to other users for equipment tests. The site is underlain by glacial gravels and clays which reach thicknesses in excess of 30 m. Surveys of the site have been completed with the following geophysical systems: Geonics EM-31 and EM-34; Apex Max-Min; Huntec Mk4 IP with Phoenix IP-T1 transmitter; Geometrics Proton Magnetometer; McPhar vertical field Fluxgate magnetometer; Androtex TDR6 IP with Phoenix IP-T1 transmitter; Geometrics 12 channel refraction seismic system; and Pulse Echo Ground Penetrating Radar. The site has proved to be well suited to serve as a test range. The addition of yet more features to the site is being planned.

Early geophysical maps published by A. Petermann

Czech Academy of Sciences Publication Activity Database

Kozák, Jan; Vaněk, Jiří

2012-01-01

Roč. 56, č. 4 (2012), s. 1109-1122 ISSN 0039-3169 Institutional research plan: CEZ:AV0Z30120515 Keywords : August Petermann * Geographische Mitteilungen * geophysical maps Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.975, year: 2012

Infrared Spectroscopy and Stable Isotope Geochemistry of Hydrous Silicate Glasses

Energy Technology Data Exchange (ETDEWEB)

Stolper, Edward

2007-03-05

The focus of this DOE-funded project has been the study of volatile components in magmas and the atmosphere. Over the twenty-one year period of this project, we have used experimental petrology and stable isotope geochemistry to study the behavior and properties of volatile components dissolved in silicate minerals and melts and glasses. More recently, we have also studied the concentration and isotopic composition of CO2 in the atmosphere, especially in relation to air quality issues in the Los Angeles basin.

Numerical modeling of regional stress distributions for geothermal exploration

Science.gov (United States)

Guillon, Theophile; Peter-Borie, Mariane; Gentier, Sylvie; Blaisonneau, Arnold

2017-04-01

Any high-enthalpy unconventional geothermal projectcan be jeopardized by the uncertainty on the presence of the geothermal resource at depth. Indeed, for the majority of such projects the geothermal resource is deeply seated and, with the drilling costs increasing accordingly, must be located as precisely as possible to increase the chance of their economic viability. In order to reduce the "geological risk", i.e., the chance to poorly locate the geothermal resource, a maximum amount of information must be gathered prior to any drilling of exploration and/or operational well. Cross-interpretation from multiple disciplines (e.g., geophysics, hydrology, geomechanics …) should improve locating the geothermal resource and so the position of exploration wells ; this is the objective of the European project IMAGE (grant agreement No. 608553), under which the work presented here was carried out. As far as geomechanics is concerned, in situ stresses can have a great impact on the presence of a geothermal resource since they condition both the regime within the rock mass, and the state of the major fault zones (and hence, the possible flow paths). In this work, we propose a geomechanical model to assess the stress distribution at the regional scale (characteristic length of 100 kilometers). Since they have a substantial impact on the stress distributions and on the possible creation of regional flow paths, the major fault zones are explicitly taken into account. The Distinct Element Method is used, where the medium is modeled as fully deformable blocks representing the rock mass interacting through mechanically active joints depicting the fault zones. The first step of the study is to build the model geometry based on geological and geophysical evidences. Geophysical and structural geology results help positioning the major fault zones in the first place. Then, outcrop observations, structural models and site-specific geological knowledge give information on the fault

Geophysical methods in uranium mining

International Nuclear Information System (INIS)

Koehler, K.

1989-01-01

In uranium prospecting, exploration, milling, and mining there is an urgent need to have information on the concentration of uranium at all steps of handling uranium containing materials. To gain this information in an effective way modern geophysical methods have to be applied. Publications of the IAEA and NEA in this field are reviewed in order to characterize the state of the art of these methods. 55 refs

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

Science.gov (United States)

McAdoo, B. G.

2003-12-01

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

EMSL Geochemistry, Biogeochemistry and Subsurface Science-Science Theme Advisory Panel Meeting

Energy Technology Data Exchange (ETDEWEB)

Brown, Gordon E.; Chaka, Anne; Shuh, David K.; Roden, Eric E.; Werth, Charles J.; Hess, Nancy J.; Felmy, Andrew R.; Rosso, Kevin M.; Baer, Donald R.; Bailey, Vanessa L.; Bowden, Mark E.; Grate, Jay W.; Hoyt, David W.; Kuprat, Laura R.; Lea, Alan S.; Mueller, Karl T.; Oostrom, Martinus; Orr, Galya; Pasa-Tolic, Ljiljana; Plata, Charity; Robinson, E. W.; Teller, Raymond G.; Thevuthasan, Suntharampillai; Wang, Hongfei; Wiley, H. S.; Wilkins, Michael J.

2011-08-01

This report covers the topics of discussion and the recommendations of the panel members. On December 8 and 9, 2010, the Geochemistry, Biogeochemistry, and Subsurface Science (GBSS) Science Theme Advisory Panel (STAP) convened for a more in-depth exploration of the five Science Theme focus areas developed at a similar meeting held in 2009. The goal for the fiscal year (FY) 2011 meeting was to identify potential topical areas for science campaigns, necessary experimental development needs, and scientific members for potential research teams. After a review of the current science in each of the five focus areas, the 2010 STAP discussions successfully led to the identification of one well focused campaign idea in pore-scale modeling and five longer-term potential research campaign ideas that would likely require additional workshops to identify specific research thrusts. These five campaign areas can be grouped into two categories: (1) the application of advanced high-resolution, high mass accuracy experimental techniques to elucidate the interplay between geochemistry and microbial communities in terrestrial ecosystems and (2) coupled computation/experimental investigations of the electron transfer reactions either between mineral surfaces and outer membranes of microbial cells or between the outer and inner membranes of microbial cells.

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

Science.gov (United States)

2012-04-01

6 Figure 2-3. Flowchart illustrating the old, ad-hoc approach of processing...Figure 2-3. Flowchart illustrating the old, ad-hoc approach of processing and integrating multiple geophysical datasets. Each color represents a... beginner , intermediate, and expert user. Most users agreed that the software is very effective for beginners because: (1) it provides a geophysics

Geophysical investigation programme of Northern Switzerland: Gravimetric measurements 81/82

International Nuclear Information System (INIS)

Klingele, E.; Schwendener, H.

1984-10-01

Within the frame of the geophysical investigations of the NAGRA in the northern part of Switzerland the Swiss Geophysical Commission has measured 4954 gravity stations. The gravity data were processed and presented as Bouguer-anomaly and residual anomaly maps. The densities used for the corrections were 2.40 and 2.67 g/cm 3 . The residual field showed a negative anomaly along an axis passing through Weiach and Villigen. This anomaly can be interpreted quantitatively in terms of depth of the crystalline basement. (author)

Geophysical data fusion for subsurface imaging. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-10-01

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

Geophysical data fusion for subsurface imaging. Final report

International Nuclear Information System (INIS)

1995-10-01

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

Development and implementation of the software for visualization and analysis of data geophysical loggers

Science.gov (United States)

Gordeev, V. F.; Malyshkov, S. Yu.; Botygin, I. A.; Sherstnev, V. S.; Sherstneva, A. I.

2017-11-01

The general trend of modern ecological geophysics is changing priorities towards rapid assessment, management and prediction of ecological and engineering soil stability as well as developing brand new geophysical technologies. The article describes researches conducted by using multi-canal geophysical logger MGR-01 (developed by IMCES SB RAS), which allows to measure flux density of very low-frequency electromagnetic radiation. It is shown that natural pulsed electromagnetic fields of the earthen lithosphere can be a source of new information on Earth's crust and processes in it, including earthquakes. The device is intended for logging electromagnetic processes in Earth's crust, geophysical exploration, finding structural and lithological inhomogeneities, monitoring the geodynamic movement of Earth's crust, express assessment of seismic hazards. The data is gathered automatically from observation point network in Siberia

Geophysical considerations of geothermics

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, M

1967-01-01

The development and utilization of geothermal energy is described from the standpoint of geophysics. The internal temperature of the Earth and the history and composition of magmas are described. Methods of exploration such as gravity, magnetic, thermal and electrical surveys are discussed, as are geochemical and infrared photogrammetric techniques. Examples are provided of how these techniques have been used in Italy and at the Matsukawa geothermal field in Japan. Drilling considerations such as muds, casings and cementing materials are discussed. Solutions are proposed for problems of environmental pollution and plant expansion.

geophysical and geochemical characterization of zango abattoir

African Journals Online (AJOL)

Dr A.B.Ahmed

disposal of hazardous materials, fresh groundwater supplies ... in the groundwater flow system may change considerably the conductivity of the polluted zone; hence the Geo-electric and. Electromagnetic (EM) geophysical methods could effectively be ... this field strength and phase displacement around a fracture zone.

Geochemical mapping in polluted floodplains using handheld XRF, geophysical imaging, and geostatistics

Czech Academy of Sciences Publication Activity Database

Hošek, Michal; Matys Grygar, Tomáš; Popelka, J.; Kiss, T.; Elznicová, J.; Faměra, Martin

2017-01-01

Roč. 19, APR (2017) ISSN 1607-7962. [EGU General Assembly 2017. 23.04.2017-28.04.2017, Vienna] Institutional support: RVO:61388980 Keywords : Dipole electromagneting profilling * electric resistivity tomography * floodplain contamination * geochemical mapping Subject RIV: DD - Geochemistry http://meetingorganizer.copernicus.org/EGU2017/EGU2017-3573-3.pdf

Geophysical Monitoring of Hydrological and Biogeochemical Transformations associated with Cr(VI) Bioremediation

International Nuclear Information System (INIS)

Hubbard, Susan; Williams, Kenneth H.; Conrad, Mark E.; Faybishenko, Boris; Peterson, John; Chen, Jinsong; Long, Philip E.; Hazen, Terry C.

2008-01-01

Understanding how hydrological and biogeochemical properties change over space and time in response to remedial treatments is hindered by our ability to monitor these processes with sufficient resolution and over field relevant scales. Here, we explored the use of geophysical approaches for monitoring the spatiotemporal distribution of hydrological and biogeochemical transformations associated with a Cr(VI)bioremediation experiment performed at Hanford, WA. We first integrated hydrological wellbore and geophysical tomographic datasets to estimate hydrological zonation at the study site. Using results from laboratory biogeophysical experiments and constraints provided by field geochemical datasets, we then interpreted time-lapse seismic and radar tomographic datasets, collected during thirteen acquisition campaigns over a three year experimental period, in terms of hydrological and biogeochemical transformations. The geophysical monitoring datasets were used to infer: the spatial distribution of injected electron donor; the evolution of gas bubbles; variations in total dissolved solids (nitrate and sulfate) as a function of pumping activity; the formation of precipitates and dissolution of calcites; and concomitant changes in porosity. Although qualitative in nature, the integrated interpretation illustrates how geophysical techniques have the potential to provide a wealth of information about coupled hydrobiogeochemical responses to remedial treatments in high spatial resolution and in a minimally invasive manner. Particularly novel aspects of our study include the use of multiple lines of evidence to constrain the interpretation of a long-term, field-scale geophysical monitoring dataset and the interpretation of the transformations as a function of hydrological heterogeneity and pumping activity

Cyclic Investigation of Geophysical Studies in the Exploration and Discovery of Natural Resources in Our Country

International Nuclear Information System (INIS)

Gonulalan, A. U.

2007-01-01

Although the methods of exploration geophysics were first utilized after the discovery of an oil field in 1921, they have also applied in the old centuries. Likewise, the half of the total production in the United States of America is covered by new oil fields discovered by utilizing geophysical methods. The industry's energy necessity increases the interest to oil. The investments in the field of geophysics by the companies which makes large amount of money in order to discover new oil fields, widespread use of computers, the developments of space technology and world-wide nuclear competition even though its great danger for human beings have great share in the development of geophysics. Our country has 18 different types mines which has more than 10 billion $ potential. Geophysical engineers have great Kowledge and labor in the discovery of 1,795 trillion wealth from borax to building stone, and 60 billion $ oil and gas. On the other hand, as 1,5 billion investment in the field of geophysics is only 0.08 % of total investments, the increase of investments will add more contribution

Advances in geochemistry during the last four decades: A personal perspective

International Nuclear Information System (INIS)

Galimov, Eric M.

2009-01-01

This is the author's speech at the meeting in Cologne (2007) to celebrate the 40th anniversary of the International Association of Geochemistry and Cosmochemistry, which the author served as the President in 2000 to 2004. The paper narrates the author's personal involvement in important scientific programs during the last 4 decades, including implementation of isotope techniques, oil-and-gas research, diamond research, deep-sea drilling, space research, molecular biology and the origin of life.

Relationship between geochemical and geomechanical properties of magnesia building material. Final report; Zusammenhang von Chemismus und mechanischen Eigenschaften des MgO-Baustoffs. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Freyer, Daniela [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Anorganische Chemie; Gruner, Matthias [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Bergbau und Spezialtiefbau; Popp, Till [Institut fuer Gebirgsmechanik GmbH (IFG), Leipzig (Germany); and others

2015-06-15

Long-term isolation of radioactive wastes from the biosphere imposes particular demands an potential building materials for engineered barrier systems (EBS). Due to its proposed longterm stability in salt formations MgO-based (''Sorel'') mortar or concrete is the preferred material option for construction of dam or shaft seals based and more than 100 years practical experiences. Fundamental investigations concerning geochemical and geomechanical properties of the Sorel-building material were performed in the framework of an interdisciplinary research project of the IfAC (Institut fuer Anorganische Chemie) and the IfBUS (Institut fuer Bergbau und Spezialtiefbau) both of University TU Bergakademie Freiberg in cooperation with the IfG Leipzig (Institut fuer Gebirgsmechanik GmbH). The sophisticated investigation approach consisting of a step-by-step procedure, which delivers a comprehensive understanding of the strongly interrelated aspects and processes. This facilitates development of tailored building material mixtures for all technical purposes, e.g. for shotcrete or site concrete applications. Chemical phase formation and stability of sorel binder phases of the magnesia building material were investigated focusing and the solubility equilibria in the basic system Mg(OH){sub 2} - MgCI{sub 2} - H{sub 2}O and Mg(OH){sub 2} - MgSO{sub 4} - H{sub 2}.Two building material mixtures were developed. Both mixtures are optimized under consideration of their flow and solidification behavior and the rheology of the binder suspension, which was modified by adding filler materials. In particular, the used magnesium oxide reactivity was found to be the prime factor for the temporary binder phase formation and heat supply, e.g. too reactive MgO leads to earlier and higher setting temperatures correlating to earlier hardening which affects the material workability. The reliability of results was proven by comparisons with measured properties during large in situ

Stress field sensitivity analysis within Mesozoic successions in the Swiss Alpine foreland using 3-D-geomechanical-numerical models

Science.gov (United States)

Reiter, Karsten; Hergert, Tobias; Heidbach, Oliver

2016-04-01

The in situ stress conditions are of key importance for the evaluation of radioactive waste repositories. In stage two of the Swiss site selection program, the three siting areas of high-level radioactive waste are located in the Alpine foreland in northern Switzerland. The sedimentary succession overlays the basement, consisting of variscan crystalline rocks as well as partly preserved Permo-Carboniferous deposits in graben structures. The Mesozoic sequence represents nearly the complete era and is covered by Cenozoic Molasse deposits as well as Quaternary sediments, mainly in the valleys. The target horizon (designated host rock) is an >100 m thick argillaceous Jurassic deposit (Opalinus Clay). To enlighten the impact of site-specific features on the state of stress within the sedimentary succession, 3-D-geomechanical-numerical models with elasto-plastic rock properties are set up for three potential siting areas. The lateral extent of the models ranges between 12 and 20 km, the vertical extent is up to a depth of 2.5 or 5 km below sea level. The sedimentary sequence plus the basement are separated into 10 to 14 rock mechanical units. The Mesozoic succession is intersected by regional fault zones; two or three of them are present in each model. The numerical problem is solved with the finite element method with a resolution of 100-150 m laterally and 10-30 m vertically. An initial stress state is established for all models taking into account the depth-dependent overconsolidation ratio in Opalinus Clay in northern Switzerland. The influence of topography, rock properties, friction on the faults as well as the impact of tectonic shortening on the state of stress is investigated. The tectonic stress is implemented with lateral displacement boundary conditions, calibrated on stress data that are compiled in Northern Switzerland. The model results indicate that the stress perturbation by the topography is significant to depths greater than the relief contrast. The

EGS Richardson AGU Chapman NVAG3 Conference: Nonlinear Variability in Geophysics: scaling and multifractal processes

OpenAIRE

D. Schertzer; S. Lovejoy; S. Lovejoy

1994-01-01

1. The conference The third conference on "Nonlinear VAriability in Geophysics: scaling and multifractal processes" (NVAG 3) was held in Cargese, Corsica, Sept. 10-17, 1993. NVAG3 was joint American Geophysical Union Chapman and European Geophysical Society Richardson Memorial conference, the first specialist conference jointly sponsored by the two organizations. It followed NVAG1 (Montreal, Aug. 1986), NVAG2 (Paris, June 1988; Schertzer and Lovejoy, 1991), five consecutive annual ...