Premium
The Snake River Plain Experiment revisited. Relationships between a Farallon plate fragment and the transition zone
Author(s) -
Beucler Eric,
Chevrot Sébastien,
Montagner JeanPaul
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl008345
Subject(s) - classification of discontinuities , discontinuity (linguistics) , geology , seismology , transition zone , hotspot (geology) , plume , induced seismicity , mantle (geology) , mantle plume , plate tectonics , seismic array , geophysics , geodesy , physics , meteorology , tectonics , lithosphere , mathematical analysis , mathematics
We reconsider the analysis of the 93 PASSCAL‐OREGON SRP experiment data. The techniques applied to the processing of Pds waves, which are P to S conversions at seismic discontinuities at depth d in the receiver region, differ from those employed by Dueker & Sheehan [1997]. We perform global move‐out corrections and migration, taking advantage of the alignment of seismicity along the great circle described by the array (South America, and the Kuril and Aleutians islands). We do not detect a deep signature of a mantle plume. The 410 km discontinuity exhibits a fragmented aspect, which prevents us from reliably estimating the transition zone thickness. The 660 km discontinuity is clearly more visible, and largely deflected in a large part of the profile. We associate this anomalous behaviour and the noisy aspect of the discontinuities with the presence of a Farallon plate fragment.