This blog will describe the running of FMTT on the AVF.

INSTALLATION

The installation was done by following the instructions obtained from

http://rses.anu.edu.au/~nick/teletomo.html

In fact, all the necessary files are attainable in an all in one download as a compressed Unix gzipped and tarred file specified in that link. In which it includes the instruction manual, a research paper of its application, and a couple of examples.

In a nutshell, to install all we need to do is to run the shell script compileall after the compressed file has been unpacked. But for things to run smoothly, prior to running the shell script what we did was:

  • Edit line 22 of  compileall and line 5 of source/aktimes/Makefile into the appropriate Fortran compiler. In my case this is gfortran.
  • Still in compileall, add ./ before remodl and setbrn in line 82 and 83 respectively so that these can be found during compilation.
  • Edit line and line 19 and line 181 of syntht.f90 source file. Delete (KIND=i10) in both lines to avoid mismatch of function error.

Compilation complete

FMTT itself consist of several individual executable programs. Each one requires an input file which name is identical to the executable except for the .in extension. In these input files we can specify and modify the parameters so that the desirable inversion routine is performed. More details on each program can be found inside the instruction manual.

An executable worth to note is tomo3dt, which perform the whole tomographic inversion as opposed to run the necessary executable programs one after the other. Another notable mention is gmtslicet. This program is used to help plot and visualize the inversion result as depth, E-W, and N-S slices. The complete plotting procedure is based on GMT scripts (GMT stands for Generic Mapping Tools).

Running the Example

Two examples were provided in the compressed file. Prior to do any of the examples, ak135.hed and ak135.tbl need to be copied into the respective example directory. These files can be found in source/aktimes after compilation. Once the files are copied, simply execute tomo3dt from the directory. It should returns the following lines:

gugi@sc-9020-hs:~/AVF/fmtt_v1.0/example1$ tomo3dt
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!
Program fm3dt has finished successfully!

The number of times the line “Program fm3dt has finished successfully!” is repeated depends on the number of iteration specified in the tomo3dt.in, the input file for tomo3dt. This shows that we have managed to perform a successful tomographic inversion.

 

Plotting the Examples

After tomo3dt has been successfully run and the rounding issue in gridi.vtx and gridc.vtx has been adjusted, the results are visualized using gmtslicet and GMT. Go to the subdirectory /gmtplot and execute gmtslicet. Prior to executing gmtslicet, the files gridi.vtx and gridc.vtx might need to be adjusted. In the top lines of both files, the numbers round off differently to each other which could result in an error while running gmtslicet. Equalizing these values will solve the error. Nick Rawlinson kindly provides us with an updated gmtslicet.f90 source file. It meant to tackle the rounding problem. It works in some computer but somehow it could be machine specific.

The execution of gmtslicet will produce three bound .gmt files (among others) for depth, E-W, and N-S strike. These are used by the plotting scripts plotd, plotew, and plotns. Prior to running these scripts, some modification were made. #!/bin/csh was added on the top of each script file. Then, depending on how GMT is called in your computer, gmt may need to be added before each GMT command namely gmtset, xyz2grd, grdimage, psscale, psxy, pscoast. Output file can also be modified.

The results of running the plotting scripts are of .ps file type which can be viewed. Depth or E-W or N-S slice is depicted by their respective script file.