Data Services Products: EMC-LLNL-G3Dv3 Earth model LLNL-G3Dv3

Summary

Simmons, Myers, Johannesson & Matzel (2012) , is a global-scale model of the crust and mantle P-wave velocity with regional-scale details. The model is parameterized using a spherical tessellation with node spacing of ~1 degree in the upper mantle and ~2 degrees in the lower mantle.

Description

Name LLNL-G3Dv3
Title A global P wave tomography model based on regional and teleseismic travel times
Type 3-D Tomography Earth Model
Sub Type P velocity
Year 2012
Short Description   LLNL-G3Dv3 is a global-scale model of the crust and mantle P-wave velocity with regional-scale details. The model is parameterized using a spherical tessellation with node spacing of ~1 degree in the upper mantle and ~2 degrees in the lower mantle. Although a spherical tessellation was used to define the lateral positioning of nodes, the model itself is aspherical with Earth’s ellipticity, mantle stretching and undulating discontinuities in the crust and upper mantle built-in. In total, the model consists of 57 layers from the surface to the core and ~1.6 million nodes. 3-D ray tracing and a multi-scale imaging technique (PMTI, Simmons et al., 2011 ) were employed to create the image.
Authors:  
Nathan A. Simmons
  Atmospheric, Earth and Energy Division
  Lawrence Livermore National Laboratory
  Livermore, California, USA
Stephen C. Myers
  Atmospheric, Earth and Energy Division
  Lawrence Livermore National Laboratory
  Livermore, California USA
Gardar Johannesson
  Systems and Decision Sciences
  Lawrence Livermore National Laboratory
  Livermore, California USA
Eric Matzel
  Atmospheric, Earth and Energy Division
  Lawrence Livermore National Laboratory
  Livermore, California USA
 
Previous Model
Reference Model
Model Download
LLNL_G3Dv3_Vp_Model.zip (~34 MB) — Complete model package containing:
  • plain text files with the raw model defined on a spherical tessellation grid
  • plain text files with the model interpolated to a regular 1-degree lat/lon grid
  • plain text files with model layer average properties
Velocity values are expressed as absolute velocity and percentage variations relative to the layer average.
Model Homepage
Depth Coverage Surface to core-mantle boundary (CMB)
Areal Coverage Global (-90°/90°, -180°/180°)
 
Data Set Description The model was developed using over 2.8 million groomed and reprocessed P and Pn travel times with events located with the Bayesloc global multiple event location technique (Myers et al. 2007, 2009, 2011 ). Original data sources include the EHB bulletin (Engdahl et al., 1998 ) provided by the International Seismological Centre (ISC), the National Earthquake Information Center (NEIC) bulletin, and a variety of regional bulletins. Additional data are derived from seismic deployments for Peaceful Nuclear Explosions (PNE’ss), large refraction surveys, the USARRAY Transportable Array (TA) and temporary PASSCAL deployments around the world (IRIS ).
 
Supplemental Information The supplemental information page for this model that also includes the LLNL-Earth3D code for extracting model parameters, tracing rays, and computing travel times.
 

LLNL-G3Dv3 P-wave velocity in selected upper mantle layers

LLNL-G3Dv3 P-wave velocity in selected upper mantle layers (lower mantle not shown). See Simmons, Myers, Johannesson & Matzel (2012) for more details.

Citation

  • Simmons, N.A., S.C. Myers, G. Johannesson, and E. Matzel. 2012. “LLNL-G3Dv3: Global P wave tomography model for improved regional and teleseismic travel time prediction.” J. Geophys. Res. 117:B10302, doi:10.1029/2012JB009525.
  • Trabant, C., A. R. Hutko, M. Bahavar, R. Karstens, T. Ahern and R. Aster (2012), Data products at the IRIS DMC: stepping-stones for research and other application, Seismological Research Letters, 83(6), 846:854. doi: 10.1785/0220 120032

References

  • Engdahl, E.R., R. van der Hilst, and R. Buland. 1998. “Global teleseismic earthquake relocation with improved travel times and procedures for depth determination.” Bull. Seismol. Soc. Am., 88:722-743.
  • Myers, S.C., G. Johannesson, and W. Hanley. 2007. “A Bayesian hierarchical method for multiple-event seismic location.” Geophys. J. Int., 171:1049-1063, doi:10.1111/j.1365-246X.2007.03555.x.

Credits

  • N.A. Simmons, S.C. Myers, G. Johannesson, and E. Matzel

DOI

doi:10.1029/2012JB009525

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