near-surface geophysics Articles

  • Coupled ADCPs can yield complete Reynolds stress tensor profiles in geophysical surface flows

    We introduce a new technique to measure profiles of each term in the Reynolds stress tensor using coupled acoustic Doppler current profilers (ADCPs). The technique is based on the variance method which is extended to the case with eight acoustic beams. Methods to analyze turbulence from a single ADCP rely on questionable assumptions on turbulence anisotropy ratios and on the requirement of ...


    By Teledyne RD Instruments

  • The Mycenaean drainage works of north Kopais, Greece: a new project incorporating surface surveys, geophysical research and excavation

    The attempt to drain the Kopais Lake was one of the most impressive and ambitious technical works of prehistoric times in Greece, inspiring myths and traditions referring to its construction and operation. The impressive remnants of the Mycenaean hydraulic works represent the most important land reclamation effort during prehistoric Greek antiquity, thus attracting the attention of the ...


    By IWA Publishing

  • Integrated Geophysics: GPR and EMI surveys at an air force base

    PROJECT: GPR and EMI surveys at closed metallic waste disposal sites LOCATION: Hill Air Force Base Annex near Ogden, Utah PROJECT DESCRIPTION: Designed and performed a GPR survey in tandem with an EM-31 terrain conductivity survey regarding two suspected Mg/Th aeronautical debris dump sites at an Air Force base in Utah.  Survey was designed to ...


    By ECA Geophysics

  • Integrated Geophysics: Magnetic / EMI surveys at an air force base

    PROJECT: EMI and Magnetic surveys at closed waste disposal sites LOCATION: Holloman Air Force Base near Alamogordo, New Mexico PROJECT DESCRIPTION: Designed and performed total-field magnetometer surveys in tandem with EM-31 terrain conductivity (EMI) surveys of approximately 53 acres of closed landfills at an Air Force base in New Mexico.  Survey ...


    By ECA Geophysics

  • Astrobiological significance of minerals on Mars surface environment

    Despite the large amount of geomorphological, geodynamic and geophysical data obtained from Mars missions, much is still unknown about Martian mineralogy and paragenetic assemblages, which is fundamental to an understanding of its entire geological history. Minerals are not only indicators of the physical– chemical settings of the different environmentsand their later changes, but also they could ...


    By Springer

  • Integrated Geophysics: GPR and EMI surveys at an air force site in the Mojave desert

    PROJECT: GPR and EMI surveys at closed waste disposal sites LOCATION: Cuddeback Air-to-Ground Gunnery Range in the Mojave Desert near Ridgecrest, California PROJECT DESCRIPTION: Designed and performed a GPR survey in tandem with an EM-31 terrain conductivity survey of nine closed landfilling areas at an abandoned Air Force gunnery range located in the ...


    By ECA Geophysics

  • Technology array enables linked surveys above and below the surface

    CONSULTANTS at GEL Geophysics LLC, a geophysical and subsurface utility engineering consulting firm based in Charleston, South Carolina, in collaboration with the Ontario, California, office of David Evans and Associates Inc., a professional consulting firm, have combined existing surveying technology to create a system that is far more than a sum of its parts. The innovation is a multi-sensor ...


    By ImpulseRadar

  • Surface borehole resistivity survey case study 1

    Surface borehole method can be used to effectively maximise the value of existing boreholes. This is because surface-boreholre method can give operator more geological and geophysical information around the borehole. For example, we did a surface-borehole survey, where there was already well-known mineralisation existing between 60-80m in Figure one and 100-115m. The inversion resistivity ...

  • Multilevel Groundwater Assessment of Confining Unit in a Bedrock Sequence near Sarnia, Ontario

    Untitled Document INTRODUCTION Two sites in southern Ontario were studied through instrumentation ...


    By Solinst Canada Ltd.

  • Researchers date ancient water deep beneath earth’s surface

    When a pocket of ancient water was discovered deep beneath the Earth in 2013, a team of Canadian researchers estimated it to be roughly 1.5 billion years old. At the same site, they discovered a deeper pocket of water estimated to be at least 2 billion years old, making it the oldest water on the planet. Barbara Sherwood Lollar, a University of Toronto professor who led the team that discovered ...


    By Fluence Corporation

  • Combined interpretation of radar, hydraulic, and tracer data from a fractured-rock aquifer near Mirror Lake, New Hampshire, USA

    An integrated interpretation of field experimental cross-hole radar, tracer, and hydraulic data demonstrates the value of combining time-lapse geophysical monitoring with conventional hydrologic measurements for improved characterization of a fractured-rock aquifer. Time-lapse difference-attenuation radar tomography was conducted during saline tracer experiments at the US Geological Survey ...


    By Springer

  • Case Study - Pipeline Subsidence

    Looking for sinkholes Pyramid Environmental recently performed a geophysical investigation for the National Park Service at Carlsbad Caverns National Park in Carlsbad, NM. The survey used electrical resistivity mapping (ER) to look for potential underground caves or caverns near an area designated for the construction of an underground utility line. A 2D resistivity survey ...


    By Advanced Geosciences, Inc.

  • Reservoir Monitoring in Delvina, Albania Monitoring - Case Study

    Reservoir Monitoring At the end of December 2011, STREAM OIL&GAS Ltd had planned to apply the technique of hydraulic acid fracturing in the Well D-12 of the Delvina block, aiming to increase the well’s natural gas productivity rate. In this context, Seismotech Geophysical Solutions was asked to monitor and analyze the possible microseismic activity on this area, ...


    By SeismoTech Ltd

  • A GIS-based methodology to delineate aquifer recharge areas

    A GIS-based methodology to delineate risk areas for contamination of groundwater resources is presented by identifying recharge conditions to the aquifer. Identifying the recharge areas is based upon surface and subsurface geologic conditions that may control the risk of potential oil spill contaminants into the aquifer. This study uses the Chicot aquifer system in southwest Louisiana as a pilot ...


    By Inderscience Publishers

  • Case Study - Remedial Investigation - Former Vickers Refinery, Potwin, Kansas

    MWH carried out this comprehensive investigation in order to characterize soil, geology, surface water, and groundwater and identify possible source areas and potential contaminant migration pathways. Additionally, this investigation evaluated hydraulic pathways and the interaction between aquifers, evaluate the performance of the recovery wells, and evaluate groundwater and surface water ...


    By EI LLC

  • Seismic study at the Pacific and Atlantic locks of the panama canal case study

    Panama Canal Zone Grupo Unidos Por el Canal (GUPC) was tasked with characterizing subsurface conditions within the Third Set of Locks Project for the Panama Canal. In support of their characterization efforts, GUPC requested that seismic geophysical data be acquired at four locations within the project area.  These locations include portions of the: Miraflores ...


    By GeoView, Inc.

  • Underground storage tanks case study

    MacDill Air Force Base A Phase II environmental site assessment was conducted at a military base in the southeastern United States. As part of the ESA, GeoView was contracted to perform the geophysical site assessment. The purpose of the geophysical investigation was to determine the presence and location of any underground storage tanks that may be buried within the boundaries of the ...


    By GeoView, Inc.

  • Groundwater resource exploration

    Resistivity method is very suitable for groundwater exploration. Two methods can be used, the surface method and crosshole method. Surface method is cost effective, though it is sometime not as accurate as the crosshole method. Geologists usually narrow down the exploration area and then operators can use geophysical methods to find groundwater.  Surface method involves laying two cables on ...

  • UXO discrimination using time domain electromagnetic induction

    Introduction An explosive ordnance is a munition that is either launched or fired with the intent of detonation at a specified target. An unexploded ordnance (UXO) is an explosive ordnance that, due to some malfunction, remains undetonated. As a result, the ordnance can be found at the ground surface, partially buried, or buried at a depth of up to 8 m beneath the surface. Practical and ...


    By Geonics Limited

  • Methods used to carry out six roadway investigations of sinkholes

    Abstract Karst conditions are a prevalent problem impacting many roads, bridges and highways of the United States. Six case-histories present an overview of investigations made to determine the presence of karst (sinkholes and cavities) and their possible impact on existing or new construction. These six case-histories represent projects which range from reconnaissance investigations to ...


    By Geonics Limited

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