RIGGS III: Seismic Short-Refraction Studies Using an Analytical Curve-Fitting Technique

  1. Charles R. Bentley and
  2. Dennis E. Hayes
  1. Joseph F. Kirchner1 and
  2. Charles R. Bentley2

Published Online: 16 MAR 2013

DOI: 10.1029/AR042p0109

The Ross Ice Shelf: Glaciology and Geophysics

The Ross Ice Shelf: Glaciology and Geophysics

How to Cite

Kirchner, J. F. and Bentley, C. R. (1990) RIGGS III: Seismic Short-Refraction Studies Using an Analytical Curve-Fitting Technique, in The Ross Ice Shelf: Glaciology and Geophysics (eds C. R. Bentley and D. E. Hayes), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR042p0109

Author Information

  1. 1

    Atlantic Richfield Company, Houston, Texas 77056

  2. 2

    Geophysical and Polar Research Center, University of Wisconsin, Madison, Wisconsin 53706

Publication History

  1. Published Online: 16 MAR 2013
  2. Published Print: 1 JAN 1990

ISBN Information

Print ISBN: 9780875901954

Online ISBN: 9781118664735

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Keywords:

  • Data analysis;
  • Short-refraction profiles;
  • Stations C-16, J9DC and Q13;
  • Stations H13, M14 and N19;
  • Travel time curves;
  • Velocity-depth curves

Summary

Several short-refraction profiles completed on the Ross Ice Shelf, Antarctica, during the 1976–1977 summer (austral) season (RIGGS III) have been analyzed and interpreted. Instead of estimating slopes from the travel time curves graphically, we have fit the travel times with an analytical function of a hybrid exponential and linear form by means of a nonlinear regression computer program. Differentiation of the resulting expression for the best fitting curve produces the velocity-distance function. Velocity-depth curves were evaluated via the WHB integral, and from these, density-depth values were computed using Kohnen's (1972) empirical relation. Comparisons of P waves and S waves (both horizontally and vertically polarized) along different azimuthal directions at three sites indicate substantial anisotropy in at least the upper 30–40 m and show further that transverse isotropy cannot serve as a good model for this region. Velocity gradients calculated and fit segmentally by exponential functions after the manner of Kohnen and Bentley (1973) and Robertson and Bentley (1975) yielded estimates of depths to different densification horizons. The results are in agreement with those of other similar studies.