Full waveform inversion of a p ? marine data set from the Gulf of Mexico provides estimates of the long-wavelength P-wave background velocity, anisotropic seismic source, and three high-frequency elastic parameter reeectivities which explain 70% of the total seismic data and 90% of the data in an interval around the gas sand target. The forward simulator is based on a plane-wave viscoelastic mo...

We combine classic and state-of-the-art techniques to characterize the seismic and volcanic features in the Coso area in southern California. Seismic tomography inversions are carried out to map the variations of Vp, Vs, and Vp/Vs beneath Coso. The velocities in the top layers of our model are correlated with the surface geological features. The Indian Wells Valley, with high silica content sed...

Temporal changes in seismic velocity during the earthquake cycle have the potential to illuminate physical processes associated with fault weakening and connections between the range of fault slip behaviors including slow earthquakes, tremor and low frequency earthquakes1. Laboratory and theoretical studies predict changes in seismic velocity prior to earthquake failure2, however tectonic fault...

S U M M A R Y Rayleigh wave phase velocity maps in southern Africa are obtained at periods from 6 to 40 s using seismic ambient noise tomography applied to data from the Southern Africa Seismic Experiment (SASE) deployed between 1997 and 1999. These phase velocity maps are combined with those from 45 to 143 s period which were determined previously using a two-planewave method by Li & Burke. In...

[1] The 3D Vp, Vp/Vs, Pand S-wave attenuation structure of the Cocos subduction zone in Mexico is imaged using earthquakes recorded by two temporary seismic arrays and local stations. Direct P wave arrivals on vertical components and direct S wave arrivals on transverse components from local earthquakes are used for velocity imaging. Relative delay times for P and PKP phases from teleseismic ev...

accurate measurements of physical characteristics of bone are essential for diagnosis, assessment of change following treatment, and therefore, indirectly, for evaluation of new forms of therapy. this is particularly true of osteoporosis and aging skeleton, in which fractures occur easily. methods: in this study an ultrasonic system was set-up and calibrated on plexiglas tubes of variable thick...

We collected SH-wave seismic reflection data over a shallow aquifer in southwestern British Columbia to investigate the use of such data in hydrogeologic applications. We used this data set in developing a methodology that uses cone penetrometer data as an integral part of the inversion and interpretation of the seismic data. A Bayesian inversion technique converts the seismic amplitude variati...

Removing the crustal signature from teleseismic travel times is an important procedure to reduce the trade-off between crustal and mantle velocity heterogeneities in seismic tomography. Because reverberations of longand short-period body-wave arrivals in the crust affect the waveforms of the direct arrivals differently, the crustal effects on travel times measured by waveform cross correlation ...

We deployed a dense linear array of 45 seismometers across and along the San Andreas fault near Parkfield a week after the M 6.0 Parkfield earthquake on 28 September 2004 to record fault-zone seismic waves generated by aftershocks and explosions. Seismic stations and explosions were co-sited with our previous experiment conducted in 2002. The data from repeated shots detonated in the fall of 20...