Carl Tape home)
Seismic Tomography of Southern California Using Adjoint
Carl Tape, PhD thesis, California
Institute of Technology, 2009
can be used to improve three-dimensional (3D) images
of Earth's interior. These images provide a
starting point for understanding (1) the present thermal and compositional structure of the Earth, and (2) the
past and future evolution of the Earth. With
better images, we are able to provide more accurate
simulations of earthquake ground motion, which
facilitates better assessment of seismic hazard.
My PhD thesis involved developing --- along with collaborators Jeroen
Tromp and Qinya
Liu --- a seismic tomographic technique
that employs accurate earthquake simulations
performed on supercomputers. Two papers
illustrate the theoretical background of the
technique and also demonstrate how it works using
synthetic examples (2005,
2007). Two papers show applications
of the tomographic technique to southern California,
where very strong (+/- 30%) variations are applied
to an initial 3D model in order to better fit
full-length three-component seismograms (Science
2009, Geophysical Journal
Two software packages used within our studies can be found at
for Geodynamics (CIG) :
SPECFEM3D -- a seismic
wave propagation code (Dimitri Komatitsch and Jeroen Tromp)
FLEXWIN -- a code for
automated time-window selection for seismograms (Alessia Maggi
2. ShakeMovie, a website for
downloading movies of wavefield simulations
earthquakes in southern California.
My PhD thesis (PDF format) can be downloaded from the
Caltech library here.
Download the full thesis as 00_CarlTapePhDThesis.pdf, or
pick a particular section.
2. Article in Geophysical
Tape, Liu, Maggi, Tromp:
Seismic tomography of the
southern California crust
based on spectral-element and adjoint methods (PDF)
3. Article in Science
(2009) by Tape, Liu, Maggi, Tromp:
Adjoint tomography of the
southern California crust (PDF)
Article that summarizes the research published in Science:
Land, by Sid Perkins, Science News
Explore a nice interactive
website made by Faria Chowdhury at the
Earthquake Data Center at Caltech.
Click around to view our tomographic model ("m16") of the
southern California crust.
6. The crustal model m16, along with all seismograms
and plotted comparisons.
All files are here;
first read the instructions in
(See also point 3 below.)
3. Harvard University website for the
Southern California Earthquake Center
Community Velocity Model, SCEC CVM-H 6.2.
The CVM-H 6.2 model includes
the crustal model m16 of Tape et al. (2009).