[1] We investigate temporal variations in the polarization of surface waves determined using ambient seismic noise cross‐correlations between station pairs at the time of the Mw 6.0 Parkfield earthquake of September 28, 2004. We use data recorded by the High Resolution Seismic Network’s 3‐component seismometers located along the San Andreas Fault. Our results show strong variations in azimuthal...

Shear wave splitting of SK(K)S phases is often used to examine upper mantle anisotropy. In specific cases, however, splitting of these phases may reflect anisotropy in the lowermost mantle. Here we present SKS and SKKS splitting measurements for 233 event-station pairs at 34 seismic stations that sample D′′ beneath Africa. Of these, 36 pairs show significantly different splitting between the tw...

Abstract Many factors can drive seismic anisotropy, whether it is the intrinsic condition of rock, external force, or longwave anisotropy. Saturated fluid, as one reservoir’s elements, known to trigger an anisotropic effect in far offset with Vertical Transverse Isotropic character. Anisotropy on presents hockey stick curving that a combination two-parameter could correct during move-out: V NMO...

The Nazca, Caribbean, and South America plates meet in northwestern South America where the northern end of the Andean volcanic arc and Wadati-Benioff zone seismicity indicate ongoing subduction. However, the termination of Quaternary volcanism at ~5.5°N and eastward offset in seismicity underneath Colombia suggest the presence of complex slab geometry. To help link geometry to dynamics, we ana...

Despite its importance for ourunderstandingof physical processes associatedwith subduction, the geometry of mantle flow in subduction zones remains poorly understood, particularly in the mantle wedge above subducting slabs. Constraints onmantle flowanddeformation canbeobtainedbymeasurements of shearwave splitting, a valuable tool used to characterize the geometry and strength of seismic anisotr...

[1] We apply seismic interferometry to strong-motion records to detect the near-surface (i.e., an upper few hundred meters deep) change in anisotropy caused by the MW 9.0 Tohoku-Oki earthquake on 11 March 2011. We show that the earthquake increased the difference between fast and slow shear-wave velocities arising from shear-wave splitting in most parts of northeastern Japan, but it did not sig...