The Southern California Velocity Model with geotechnical layer (cvms)

The Southern California Velocity Model developed by SCEC, Caltech and USGS with geotechnical layer

CVM-S4 is a three-dimensional (3D) seismic velocity model of southern California developed by the Southern California Earthquake Center. The model consists of detailed, rule-based representations of the major southern California basins (Los Angeles basin, Ventura basin, San Gabriel Valley, San Fernando Valley, Chino basin, San Bernardino Valley, and the Salton Trough), embedded in a 3D crust over a variable depth Moho. Outside of the basins, the model crust is based on regional tomographic results. The model Moho is represented by a surface with the depths determined by the receiver function technique. Shallow basin sediment velocities are constrained by geotechnical data. CVM-S4 updates earlier versions of the model by 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 model element spacing is 20 km. S-wave velocities are determined from laboratory Vp/Vs ratios. The most prominent features imaged in the results are high P-wave velocities (+3%) in the uppermost mantle beneath the northern Los Angeles basin, and high-velocity anomaly (+3%) to depths of 200 km beneath the Transverse Ranges, crosscutting the San Andreas fault. It incorporates the upper mantle seismic velocity heterogeneities into the SCEC Southern California reference seismic velocity model.

Kohler, MD, Magistrale, H, Clayton, RW (2003) Mantle heterogeneities and the SCEC ref three-dimensional seismic velocity model version 3. Bulletin of the Seismological Society of America 93(2): 757–774

Installation

This package is intended to be installed as part of the UCVM framework, version 25.7 or higher.

Contact the authors

If you would like to contact the authors regarding this software, please e-mail software@scec.org. Note this e-mail address should be used for questions regarding the software itself (e.g. how do I link the library properly?). Questions regarding the model's science (e.g. on what paper is the CVMS based?) should be directed to the model's authors, located in the AUTHORS file.

To build in standalone mode

To install this package on your computer, please run the following commands:

  aclocal
  autoconf
  automake --add-missing --force-missing
  ./configure --prefix=/dir/to/install
  make
  make install

By default, the MPI query interface is not built. To build the MPI version, uncomment the appropriate TARGET line ./src/Makefile and change the compiler FC specification to the appropriate Fortran compiler wrapper.

cvms_query

ASCII query interface(C api) accepts points from stdin with format (lat, lon, dep (m)) and write data material p roperties to stdout.

cvms_txt

ASCII query interface(Fortran api) accepts points from stdin with format (lat, lon, dep (m)) and writes data material properties to stdout with format (lat, lon, dep, vp, vs, density).

cvms_bin

Binary query interface reads a configuration file named 'cvm-input' with the following items:

line 1: number of points
line 2: path to input lon file
line 3: path to input lat file
line 4: path to input dep file
line 5: path to output rho file
line 6: path to output vp file
line 7: path to output vs file

The input and output files are in binary (float) format, with each containing the number of points specified on line 1.

MPI query interface cvms_mpi

Reads a configuration file named 'cvm-input' with the following items:

line 1: number of points
line 2: path to input lon file
line 3: path to input lat file
line 4: path to input dep file
line 5: path to output rho file
line 6: path to output vp file
line 7: path to output vs file

The input and output files are in binary (float) format, with each containing the number of points specified on line 1.