Surface Structure beneath the Pacific

Seismic Structure of the Mantle Beneath the Southwestern Pacific

We jointly invert 1396 frequency-dependent travel times of turning and surface waves such as S, sS, SS, sSS, SSS, Sa, R1, and G1, together with 82 travel times of multiple ScS waves, to obtain a high-resolution, two-dimensional (2-D) vertical tomogram for the corridor between the Ryukyu subduction zone and Hawaii, which traverses the Hawaiian Swell between Midway and Oahu. The data analysis, in...

Whole mantle shear structure beneath the East Pacific Rise

[1] We model broadband seismograms containing triplicated S, S, and S along with ScS to produce a pure path one-dimensional model extending from the crust to the core-mantle boundary beneath the East Pacific Rise. We simultaneously model all body wave shapes and amplitudes, thereby eliminating depth-velocity ambiguities. The data consist of western North American broadband recordings of East Pa...

Upper mantle structure beneath the eastern Pacific Ocean ridges

[1] We analyze vertical component body and surface waves for 10 Mw > 5 earthquakes, recorded by ocean bottom seismometers at regional and teleseismic distances. Through waveform modeling, we place new constraints on along-axis variation in temperature and partial melt beneath the eastern Pacific ridges. The resulting best fit models show over 9% variation in average lithosphere shear velocities...

Looking beneath the surface.

Slab‐plume interaction beneath the Pacific Northwest

[1] The Pacific Northwest has undergone complex plate reorganization and intense tectono‐volcanic activity to the east during the Cenozoic (last 65 Ma). Here we show new high‐resolution tomographic images obtained using shear and compressional data from the ongoing USArray deployment that demonstrate first that there is a continuous, whole‐ mantle plume beneath the Yellowstone Snake River Plain...