Lowermost mantle anisotropy beneath the northwestern Pacific: Evidence from PcS, ScS, SKS, and SKKS phases

Lowermost mantle anisotropy beneath the northwestern Pacific: Evidence from PcS, ScS, SKS, and SKKS phases

[1] In this study, we utilize data from broadband seismic stations of the Japanese F-net network to investigate anisotropic structure in the lowermost mantle beneath the northwestern Pacific. The comparison of shear wave splitting from phases that have similar paths in the upper mantle but different paths in the lowermost mantle, such as PcS/ScS or SKS/SKKS, can yield constraints on anisotropy ...

Complex anisotropy in D′′ beneath the eastern Pacific from SKS–SKKS splitting discrepancies

Imaging the Lowermost Mantle ( D " ) Beneath the Pacific Ocean with SKKS Coda Waves

We apply a generalized Radon transform (GRT) to SKKS data to obtain a large-scale high-resolution image of the lowermost mantle (400 kilometers above the core-mantle boundary) beneath the Pacific Ocean (1250 E-750 W, 450 S-650 N in this work). More than 4,000,000 radial teleseismic traces from about 8,000 events (mb >= 5.8) between 1990 and 2015, globally recorded by one or more of a total ~27,...

Complex seismic anisotropy at the border of a very low velocity province at the base of the Earth’s mantle

[1] We constrain the anisotropy associated with a very low velocity province (VLVP) at the base of the Earth’s mantle using the SKS and SKKS waves sampling the region. Our selected high-quality data sets consist of 415 SKS and 111 SKKS waveforms for 127 deep earthquakes recorded at distances between 90 and 150 by the seismic stations in three temporary broadband PASSCAL seismic arrays: the Kaap...

Upper mantle deformation beneath the North American–Pacific plate boundary in California from SKS splitting

[1] In order to constrain the vertical and lateral extent of deformation and the interactions between lithosphere and asthenosphere in a context of a transpressional plate boundary, we performed teleseismic shear wave splitting measurements for 65 permanent and temporary broadband stations in central California. We present evidence for the presence of two anisotropic domains: (1) one with clear...