Research School of Earth Sciences
This web page distributes an iterative non-linear traveltime tomography code
in 2-D spherical shell coordinates (constant radius, variable latitude and longitude).
One possible application of the code is surface wave tomography using, for example,
traveltimes of high frequency interstation rayleigh waveforms extracted from the
ambient seismic noise field. The forward problem is solved using a grid based
eikonal solver known as the fast marching method (FMM), and the inverse problem is
solved using a subspace inversion method. Note that the code is not suitable for
models which require the Earth's poles or its periodicity to be taken into account.
The software is written in Fortran 90, and uses shell scripts to
iteratively apply the various pieces of code in order to solve the complete
non-linear tomography problem. The code has been tested
on a number of platforms, and should work on most computers that have acces to
compilers distributed by the likes of GNU, NAG, Portland, Pathscale, Intel,
Fujitsu and Sun. A detailed instruction manual is supplied with the distribution, and can
also be downloaded below in PDF format:
15/04/2008 - Bug fix: division by zero in fm2dss repaired.
Version 1.1 posted on 30/07/2008
Version 1.1 does not introduce any new features compared to version 1.0, but does include several bug fixes. These include:
To obtain the complete source code, detailed documentation and example input files, download the Unix gzipped and tarred file below:
fmst_v1.1.tar.gz (2.6 Mb)
To unpack the contents of this file, type something like:
gunzip -c fmst_v1.1.tar.gz | tar xvof -
tar -xvzf fmst_v1.1.tar.gz
at the command prompt. The contents of the tar archive will be placed in the extraction directory. Instructions on how to use the code can be found in the directory docs.