Accurate earthquake source parameters such as fault mechanism, depth, and moment magnitude are not only important in seismic-hazard assessment, but also are crucial to studies of earthquake rupture processes and seismotectonics. Although large earthquakes (Mw 7+) may cause substantial damage, they occur less frequently. In contrast, moderate earthquakes (Mw 5.0–6.5) occur with much higher frequ...

We present a method for joint inversion of teleseismic and ambient noise Rayleigh wave data for phase velocity maps from 18 to 50 s period. We adapt the two-plane wave method for teleseismic data to include ambient noise phase data. We apply themethod to data from Iceland’s ICEMELT and HOTSPOT arrays. Checkerboard tests show that the joint inversion improves phase velocity model recovery over m...

We present observations on a new precursory phase of seismic waves scattered in the deep Earth. This arrives prior to PKPab wave at epicentral distances larger than 155°, and we call it precursor. show that presence precursor is necessary consequence scattering D?, which commonly accepted cause PKPdf smaller 145°. propagate through inner core should arrive before but those, are strongly attenua...

We present, for the first time, evidence for triggered tremor beneath the island of Sumbawa, Indonesia. We show triggered tremor in response to three teleseismic earthquakes: theMw 9.

The 20 May and 14 November 1986 Hualien earthquakes occurred in a seismically active region of Taiwan. Locally determined focal mechanisms and aftershock patterns from the Taiwan Telemetered Seismographic Network indicate that both earthquakes occurred on steeply dipping reverse faults that trend NNE. This agrees with teleseismic first-motion data for the May event but not for the November even...

Converted and multiply reflected phases from teleseismic events are routinely used to create structural images of the crust-mantle boundary (Moho) and the elasticity contrasts within the crust and upper mantle. The accuracy of these images is to a large extent determined by the background velocity model used to propagate these phases to depth. In order to improve estimates of 3-D velocity varia...

The amount of seismic energy radiated from an earthquake is a key macroscopic parameter for understanding the physics of earthquakes. To resolve the important details of the earthquake process, we require more accurate estimates of energy than are currently available. In this study, we determine the energy radiated from the Mw 7.1 16 October 1999 Hector Mine, California, earthquake using region...