Sebastian Rost

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a r t i c l e i n f o Some regions of the Earth's lowermost mantle exhibit anomalous seismic properties within a thin zone, less than tens of kilometers in thickness, that directly overlies the core-mantle boundary (CMB). These regions have been dubbed Ultra-Low Velocity Zones (ULVZs) due to their greater than 10% drop in seismic velocities. High resolution(More)
Recent seismological discoveries have indicated that the Earth's core-mantle boundary is far more complex than a simple boundary between the molten outer core and the silicate mantle. Instead, its structural complexities probably rival those of the Earth's crust. Some regions of the lowermost mantle have been observed to have seismic wave speed reductions(More)
The Earth's magnetic field is generated by a dynamo in the liquid iron core, which convects in response to cooling of the overlying rocky mantle. The core freezes from the innermost surface outward, growing the solid inner core and releasing light elements that drive compositional convection. Mantle convection extracts heat from the core at a rate that has(More)
[1] Using an unusually large earthquake near the big island of Hawaii, we study the core mantle boundary (CMB) beneath the north‐northeastern Pacific between Hawaii and North America. A dense sampling of the CMB is achieved using the core‐reflected phase PcP recorded at a large number of high‐quality stations in North America, including networks in(More)
We analyzed vertical component short-period ScP waveforms for 26 earthquakes occurring in the Tonga-Fiji trench recorded at the Alice Springs Array in central Australia. These waveforms show strong precursory and postcursory seismic arrivals consistent with ultralow-velocity zone (ULVZ) layering beneath the Coral Sea. We used the Viterbi sparse spike(More)
[1] We collected a new data set of 1354 broadband SPdKS waveforms sampling the western Pacific Ocean region. These data indicate that multiple ultralow-velocity zones (ULVZs) exist in this region. We compared these data to 2.5-D synthetic seismograms computed with the PSVaxi method for a suite of 517 ULVZ models. The region beneath the North and South(More)
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