Cold, subducted lithosphere has relatively fast seismic velocity which leads to early arrivals for some vent-station paths. The effect is very large for events in the Tonga-Kermadec ep seismic zone recorded at certain New Zealand stations. These particular arrivals are very high-frequency (3 Hz or greater) and sometimes r emble two distinct phases, the later arrival appearing at about the time ...

An inversion method is presented for the reconstruction of interface geometry between two or more crustal layers from teleseismic traveltime residuals. The method is applied to 2-D models consisting of continuous interfaces separating constant-velocity layers. The forward problem of determining ray paths and traveltimes between incident wave fronts below the structure and receivers located on t...

We determine upper mantle seismic velocity heterogeneities below Southern California from the inversion of teleseismic travel-time residuals. Teleseismic P-wave arrival times are obtained from three temporary passive experiments and Southern California Seismic Network (SCSN) stations, producing good raypath coverage. The inversion is performed using a damped least-squares conjugate gradient met...

Most of the largest volcanic activity in world occurs remote places such as deep oceans or poorly monitored oceanic island arcs. Thus, our capacity monitoring volcanoes is limited to sensing and global geophysical observations. However, rapid estimation eruption parameters needed for scientific understanding eruptive process hazard estimation. We present a method rapidly identify large explosio...

All quality teleseismic recordings of the great 1906 San Francisco earthquake archived in the 1908 Carnegie Report by the State Earthquake Investigation Commission were scanned and digitized. First order results were obtained by comparing complexity and amplitudes of teleseismic waveforms from the 1906 earthquake with well calibrated, similarly located, more recent earthquakes (1979 Coyote Lake...

Abstract Tremors and low-frequency earthquakes (LFEs), which occur in the plate interface, can provide useful information about state of aseismic stress transfer mega-earthquake fault zones. We estimated distribution triggered LFEs subducted interface. Specifically, we detected Ryukyu Trench by surface waves large teleseismic using waveform records broadband short-period seismometers installed ...