Abstract
An automated, PC-based logging system has been developed to investigate marine sediment cores by full waveform transmission seismograms. High-resolution P-wave velocity and amplitude attenuation profiles are simultaneously derived from the transmission data to characterize the acoustic properties of the sediment column.
A pair of ultrasonic, piezoelectric wheel probes is used to generate and record the transmission signals travelling radially through the sediment core. Both unsplit and split cores are allowed. Mounted in a carriage driven by a stepping motor via a shaft the probes automatically move along the core liner, stopping at equidistant spacings to provide a quasi-continuous inspection of the core by the transmission data. The axial travel distance and the core diameter are determined by digital measuring tools.
First arrivals are picked automatically from the transmission seismograms using either a threshold in the seismogram's envelope or a cross-correlation algorithm taking the ‘zero-offset’ signal of both wheel probes into account. Combined with the core diameter these first arrivals lead to a P-wave velocity profile with a relative precision of 1 to 2 m s−1. Simultaneously, the maximum peak-to-peak amplitudes of the transmission seismograms are evaluated to get a first idea on the amplitude attenuation along the sediment core.
Two examples of gravity cores taken during a recent cruise of R.V. METEOR in the Western Equatorial Atlantic are presented. They yield that the P-wave profiles can be used for locating strong and fine-scale lithological changes, e.g. turbidite layers and slight variations in the sand, silt or clay content. In addition, the transmission seismograms and their amplitude spectra obviously seem to reveal a correlation between the relative amount of low-frequency spectral components and the sediment grain size, and thus provide a tool for the determination of additional, related physical or sedimentological parameters in future investigations.
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References
Baldwin, K. C., Celikkol, B., and Silva, A. J., 1981, Marine Sediment Acoustic Measurement System,Ocean Eng. 8 481–488.
Boyce, R. E., 1973, Appendix I. Physical Properties — Methods, in: Edgar, N. T., Saunders, J. B.et al. (eds.)Initial Reports of the Deep Sea Drilling Project 15, Washington (U.S. Government Printing Office), p. 1115–1127.
Boyce, R. E., 1976, I. Definitions and Laboratory Techniques of Compressional Sound Velocity Parameters and Wet-Water
Content, Wet-Bulk Density, and Porosity Parameters by Gravimetric and Gamma Ray Attenuation Techniques. in: Schlanger, S. O., Jackson, E. D.et al. (eds.),Initial Reports of the Deep Sea Drilling Project, 33, Washington (U.S. Government Printing Office), p. 931–958.
Dahlke, H. E., and Southworth, J. H., 1971, Portable Sound Velocimeter and its Application on Unopened Marine Sediment Cores, Liquids, and Solids,IEEE Transactions on Geoscience Electronics, GE-9, 74–80.
Engelhard, L., 1985, Shear Wave Well Logging from Wavetrain Analysis, in: Dohr, G. (ed.)Handbook of Geophysical Exploration, Seismic Shear Waves, Part A: Theory,15, Geophysical Press, London, p. 283–351.
Hamilton, E. L., 1971, Prediction ofin situ Acoustic and Elastic Properties of Marine Sediments,Geophysics,36 266–284.
Medwin, H., 1975, Speed of Sound in Water: A Simple Equation for Realistic Parameters,Journal of the Acoustical Society of America 58 1318–1319.
Philipp, J., 1989, Bestimmung der Kompressions- und Scherwellengeschwindigkeit Mariner Sedimente an Kastenlotkernen: Entwicklung einer Meβapparatur und Vergleich mit Sedimentologischen Parametern,Berichte Sonderforschungsbereich 313,16, Universität Kiel, 95 pp.
Schultheiss, P. J., and McPhail, S. D., 1989, An Automated P-Wave Logger for Recording Fine-Scale Compressional Wave Velocity Structures in Sediments, in: Ruddiman, W. and Sarnthein, M. (eds.),Proceedings of the Ocean Drilling Program, Scientific Results, 108, College Station TX (Ocean Drilling Program), p. 407–413.
Schumway, G., 1956, A resonant Chamber Method for Sound Velocity and Attenuation Measurement in Sediments,Geophysics 21 305–319.
Toulis, W. J., 1956, Theory of resonance method to measure the acoustic properties of sediments,Geophysics 21 299–304.
Wille, P., 1986, Acoustical properties of the ocean, in: Hellwege, K. H. and Madelung, O. (eds.),Landolt-Börnstein. Zahlenwerte und Funktionen aus Naturwissenschaften und Technik, V/3a, Springer Verlag, p. 265–382.
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Breitzke, M., Spieβ, V. An automated full waveform logging system for high-resolution P-wave profiles in marine sediments. Mar Geophys Res 15, 297–321 (1993). https://doi.org/10.1007/BF01982387
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DOI: https://doi.org/10.1007/BF01982387