STP501: An Analysis of Piston Coring through Corehead Camera Photography

    McCoy, FW
    Research assistant, Harvard UniversityWoods Hole Oclanographic Institution, CambridgeWoods Hole, Mass.Mass.

    Pages: 16    Published: Jan 1972


    Abstract

    Cameras were mounted within the corehead of a piston sampler to photograph coring operations at 35 stations in the North Atlantic ocean. Through the analysis of these photographs, the operation of the corer during descent, tripping, impact with the bottom, and ascent has been studied, providing information on its effectiveness in obtaining a representative sample of submarine soil and its influence on the surrounding sea floor. Direct determinations of the amount of penetration were possible, allowing comparisons to be made with the indirect methods of determining penetration and with the length of core recovered. These comparisons indicated that the piston cores were shortened and disturbed, often with as much as a meter of surface material missing. No consistent relationship was found between the length of core recovered and the amount of penetration. Dips of layers within the core evidently had been produced by the coring processs. Problems in piston immobilization are discussed relative to these results and a number of recommendations made for decreasing core disturbances.

    Keywords:

    coring, soils, sampling, soil profiles, marine geology, sediments, submarine topography, ocean bottom, photography, borehole cameras, penetration, deep water


    Paper ID: STP38796S

    Committee/Subcommittee: D18.02

    DOI: 10.1520/STP38796S


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