S U M M A R Y Upper-mantle seismic anisotropy has been observed using a variety of methods, including S and SKS splitting, P and Pn traveltimes, P polarization anomalies and P to S conversions, and surface waves. Care must be taken when comparing the results from different methods because of bias introduced by depth sensitivity, frequency dependence, and simplifying assumptions concerning the f...

Broadband vertical P-wave records are analyzed from 63 of the largest shallow subduction zone earthquakes which have occurred in the circum-Pacific in the last 45 yr. Most of the records studied come from a common instrument, the Pasadena, California, Benioff 1-90 seismometer. Propagation and instrument effects are deconvolved from the P-wave records using a damped least-squares inversion to ob...

Comparing teleseismic array back-projection source images of the 2011 Tohoku-Oki earthquake to results from static and kinematic finite source inversions has revealed little overlap between the regions of high and low frequency slip. Motivated by this interesting observation, backprojection studies extended to intermediate frequencies, down to about 0.1Hz, have proposed that a progressive trans...

The simulated annealing method has recently been applied to several multiparameter optimization problems, including those of geophysical inversion. A new variant of simulated annealing, called very fast simulated annealing (VFSA), overcomes some of the drawbacks of a conventional simulated annealing; it has been found to be a practical tool for geophysical inversion (Sen & Stoffa 1995). The met...

Localization tools such as the CTBTO's GA (Global Association) system work by analyzing detections of arriving phases; these detections constitute a discretized, thresholded summary of information from the underlying seismic waveforms. By contrast, our SIG-VISA (SIGnal-based Vertically Integrated Seismic Analysis) system operates directly at the level of the raw waveforms or envelopes, applying...

Seismological data recorded in the Ionian Sea by a network of seven Ocean Bottom Seismometers (OBSs) during 2017–2018 SEISMOFAULTS experiment provides close-up view seismogenic structures that are potential sources medium-high magnitude earthquakes. The high-quality signal-to-noise ratio waveforms observed for earthquakes at different scales: teleseismic, regional, and local as well single stat...