Publication Date:
2019
Description:
Abstract
At the core‐mantle boundary, most observed ultra‐low velocity zones (ULVZ's) cluster along the edges of the large low shear velocity provinces (LLSVP's) and provide key information on the composition, dynamics and evolution of the lower mantle. However, their detailed structure near slab‐like structures beneath the mid‐Pacific remains particularly challenging because of the lack of station coverage. While most studies of ULVZ's concentrate on SKS‐complexity, here we report on the multi‐pathing of ScS which expands the sampling for ULVZ's. We find the strongest multi‐pathing along a ULVZ patch located just south of Hawaii and the far northeastern edge of the LLSVP, in a zone ~200 km in width and extending 600 km southward. The anomalous ScS travel times and distorted Sdiff waveforms further reveal patches interrupted by observed enhanced D" indicative of slab‐debris influence on the complexity of the northeastern boundary of the mid‐Pacific LLSVP.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
