Upper Crustal Structure from the Santa Monica Mountains to the Sierra Nevada, Southern California: Tomographic Results from the Los Angeles Regional Seismic Experiment, Phase II (LARSE II)

Abstract

In 1999, the U.S. Geological Survey and the Southern California Earth-

Testing Waveform Predictions of 3D Velocity Models against Two Recent Los Angeles Earthquakes

“…We have digitized and recolored their tomography map and a comparison with the P-wave velocities in the three CVMs along the LARSE-II profile is shown on the right side of Figure 1. In general, the P-wave velocities in CVM-S4.26 have the highest correlation with the 2D model of Lutter et al (2004). In CVM-S4, the ▴ Figure 5.…”

“…At both stations, synthetics computed using CVM-S4.26 provide the best fit to observed seismograms than those computed using the other two CVMs . A 2D P-wave velocity model was obtained by Lutter et al (2004), who inverted a dense collection of active-source travel-time data. We have digitized and recolored their tomography map and a comparison with the P-wave velocities in the three CVMs along the LARSE-II profile is shown on the right side of Figure 1.…”

“…At depths of 4-6 km, for example, the seismic velocities are observed to change by more than 100% across horizontal distances of less than 10 km. Figure 1 compares sections through three of the SCEC models-CVM-S4, CVM-S4.26, and CVM-H11.9-with 2D tomographic models derived from a dense collection of reflection/refraction data along the two lines of the Los Angeles region seismic experiments (LARSE), LARSE I (Lutter et al, 1999) and LARSE II (Lutter et al, 2004). The models show significant differences at the basin scales, as well as deeper in the crust (Fig.…”

Full‐3‐D tomography for crustal structure in Southern California based on the scattering‐integral and the adjoint‐wavefield methods

“…In Figure 8, we compare 2-D cross sections through the three CVMs with the 2-D active-source refraction tomography models along the two profiles of the Los Angeles Region Seismic Experiments, LARSE-I [Lutter et al, 1999] and LARSE-II [Lutter et al, 2004]. Along the LARSE-I profile, underneath the San Gabriel Mountains (SGM), a low-velocity body extends down to 7 km depth in both CVM-S4.26 and Lutter et al [1999].…”

Eos, Transactions, American Geophysical Union Volume 86, Number 17, 26 April 2005

“…Controlled-source surveys using vibroseis and/or explosion sources have facilitated fi ne-scale source imaging of active fault systems such as the San Andreas [e.g., Li et al, 2004], basins [e.g., Lutter et al, 2004], and deep continental roots [e.g., Gorman et al, 2002]. Access to data sets incorporating increasingly larger numbers of high-quality instruments has also furthered data processing methodologies [e.g., Hole et al, 2001].…”