STP1420: Spatial Scale Analysis in Geophysics — Integrating Surface and Borehole Geophysics in Groundwater Studies

    Paillet, FL
    Project Chief, U.S. Geological Survey, Denver, CO

    Pages: 15    Published: Jan 2003


    Abstract

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

    Keywords:

    geophysics, borehole geophysics, electromagnetic surveys, seawater intrusion


    Paper ID: STP10915S

    Committee/Subcommittee: D18.01

    DOI: 10.1520/STP10915S


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