Reassessment of a reported S-delay under Trindade

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 S...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Nataf, H. C., Lay, T., Anderson, D. L.
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 1981
Subjects:
Online Access:https://authors.library.caltech.edu/55125/
https://authors.library.caltech.edu/55125/1/Nataf_et_al-1981-Geophysical_Research_Letters.pdf
https://resolver.caltech.edu/CaltechAUTHORS:20150224-071608312
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Summary: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.