Reassessment of a reported S-delay under Trindade

• Published in: Geophysical Research Letters
• Main Authors: Nataf, H. C., Lay, T., Anderson, D. L.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 1981
• Subjects: South Atlantic Ocean
• Online Access: https://doi.org/10.1029/GL008i010p01027

We present a correction to a paper by Okal and Anderson (1975) about multiple ScS travel-time anomalies. We have reanalyzed data for ScS_2 surface bounces in the South Atlantic Ocean. From these data an ScS_2-S residual of 23.6 seconds was found by Okal and Anderson (1975). This corresponded to an ScS_2 surface bounce point under Trindade island and was inferred to be due to very slow upper mantle associated with the Trindade hot spot. The analysis we present here invalidates this conclusion. The nature of the upper mantle under Trindade is an open issue. © 1981 by the American Geophysical Union. (Received August 3, 1981; accepted August 21, 1981.) We wish to thank Hiroo Kanamori and Don Helmberger for helpful comments. This research has been supported by the National Aeronautics and Space Administration grant number NSG-7610 and by the National Science Foundation grant number EAR 8106106. Contribution Number 3663, Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125. Published - Nataf_et_al-1981-Geophysical_Research_Letters.pdf