Introduction

This tutorial provides a complete data set for regional moment tensor inversion. Download the following:

` After downloading, execute the following steps:

Source inversion

The PDF document MomentTensorCourse.pdf provides details on the steps required to perform a regional moment tensor inversion using a grid-search technique.

If you must skip reading the tutorial, do the following:

cd RMT/MECH.NA
DO
cp RAW/*seed /home/cps/MTTEST/RMT/MECH.NA/20080418093700/20080418093700
cd /home/cps/MTTEST/RMT/MECH.NA/20080418093700/20080418093700
cd Sac
rdseed -f ../*.seed -R -d -o 1
cd ..
IDOEVT
IDOROT
IDODIST
IDOQC
cd ..
cd GRD.REG
DOGRD
DODELAY
DOPLTSAC
DOCLEANUP
cd ../HTML.REG
DOHTML
NOTES:

Advanced steps

The Greens functions distributed for this example are only the subset of distances required for the tutorial. The reason that a complete set is not provide is because of the large size of the download file.

In the directory RMT/GREEN/CUS.REG is a shell script DOIT.WK.big which computes Greens functions at finer distance intervals out to 790 km.

If you wish to work with another veolocty model, do the following:

Updates May 9, 2016

The 0XXXREG now contains prototypes for comptuoing ML and mLg as well as for applying the grid search for the full and deviaoric moment tensors. The use of these scripts is illustrated at http://www.eas.slu.edu/eqc/eqc_mt/MECH.NA/20160307004336/index.html. The differences are as follow.

The EVENT directory will now contrin the ML.REG and MLG.REG subdirectories. If the EVETN/EVENT/FINAL/rotated_sac_files has not been removed, then

cd ML.REG
DOML

cd ../HTML.REG
DOHTML
will compute ML and put the results in the HTML.REG directory.

Currently my DOSETUP will also create the directories EVENT/MTGRD.REG, EVENT/MTGRD.REG.DC and EVENT.MTGRD.REG.DEV. The grid search for the best double couple solution will give the same results at the use of wvfgrd96 in the EVENT/GRD.REG directory. The deviatoric grid search takes longer since the search is over 4 parameters instead of 3. The full moment tensor search is ove five parameters and will take much, much longer than for the double couple search. So, do the following: (a) copy the DOSTA from GRD.REG to the MTGRD.REG.DEV. Edit the DOMTGRD files to select the depth ranges. In the case of the full moment tensor, just do a few depths about the best depth for the deviatoric solution.

Extra software

Besides Computer Programs in Seismology, you will require the following:

Last changed April 15, 2012