Lateral variation of the D″ discontinuity beneath the Cocos Plate

T. Lay, Edward Garnero, S. A. Russell

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


Broadband shear wave signals from 15 deep South American earthquakes reveal small-scale variations of the D″ shear velocity discontinuity beneath the Cocos Plate. Deconvolution by average event source wavelets allows multiple event and California station combinations to be double-array stacked in 4 geographically separate reflection point bins with lateral dimensions of about 200 km. Reflections from the top of D″ are apparent in all 4 bins, with significant variations in timing and strength relative to ScS. The data are compatible with a discontinuous shear velocity increase 264 km above the core-mantle boundary that varies laterally in strength from 0.9% to 2.6%, with corresponding lateral velocity variations within D″.

Original languageEnglish (US)
Pages (from-to)L15612 1-5
JournalGeophysical Research Letters
Issue number15
StatePublished - Aug 16 2004

ASJC Scopus subject areas

  • Geophysics
  • General Earth and Planetary Sciences


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