Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 1984 | Published
Journal Article Open

Measurements of mantle wave velocities and inversion for lateral heterogeneity and anisotropy - II. Analysis by the single-station method

Abstract

Phase and group velocities of G_2, G_3, R_2 and R_3 (100-330_s) are measured by the single-station method and are inverted to give a spherical harmonic representation of the velocity lateral variation. Approximately 200 paths have been studied. The results are presented for degrees and orders up to 6. The even harmonics of the phase velocity representation are consistent with those obtained from great circle phase velocities (Paper I). The odd harmonics are less constrained and generally have larger standard deviations than the even harmonics. To suppress the poorly determined harmonics in the velocity contour maps we construct a filter which is derived from an inverse problem formulation. The filter reduces the amplitudes of regional variations, but does not change the overall pattern. The patterns of the regional variations are generally consistent with those obtained by regionalized inversion of great circle data (Paper I). The velocity maps show significant differences within oceans and continents. An analysis is made of correlations of surface wave velocities with heat flow and the non-hydrostatic geoid. The slownesses correlate well with heat flow for l = 1-6. The correlation peaks at l = 2 and 5. The geoid has an anticorrelation with the slownesses at l = 2 and 3, and a positive correlation from l = 4 to 6.

Additional Information

© 1984 Royal Astronomical Society. Received 1984 January 20; in original form 1983 July 31. The authors wish to thank Henri-Claude Nataf, Hiroo Kanamori, and Bradford Hager for suggestions. Jeffrey Given, Fumiko Tajima, and Jeanne Sauber helped us retrieve the seismograms from the GDSN day tapes at an early stage of this study. The IDA data used in this study were made available to us by courtesy of the IDA project team at the Institute of Geophysics and Planetary Physics, University of California, San Diego. This research was supported by National Aeronautics and Space Administration grant No. NSG-7610 and National Science Foundation grant No. EAR811-5236. Contribution No. 3902, Division of Geological and Planetary Sciences, California Institute of Technology.

Attached Files

Published - DLAgjras84.pdf

Files

DLAgjras84.pdf
Files (2.2 MB)
Name Size Download all
md5:14ef25246bcf0f73a673cae332d48795
2.2 MB Preview Download

Additional details

Created:
August 23, 2023
Modified:
October 26, 2023