Abstract
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 language | English (US) |
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Pages (from-to) | L15612 1-5 |
Journal | Geophysical Research Letters |
Volume | 31 |
Issue number | 15 |
DOIs | |
State | Published - Aug 16 2004 |
ASJC Scopus subject areas
- Geophysics
- General Earth and Planetary Sciences