geodesy / ym1992

Geodetic inversion code of Yabuki and Matsu'ura (1992, Geophys. J. Int.)

Geodetic data inversion tool proposed by Yabuki and Matsu'ura (1992)

Note

This Fortran 90 code is the translation of the original F77 code written by T. Yabuki.

Citation

for the methodology

Yabuki, T. and M. Matsu'ura (1992): A geodetic data inversion using a Bayesian information criterion for spatial distribution of fault slip, Geophys. J. Int. 109, 363-375, https://doi.org/10.1111/j.1365-246X.1992.tb00102.x

for the code

Shun-ichi Watanabe, Yusuke Yokota, Yuto Nakamura, & Tetsuichiro Yabuki. (2020, August 14). YM1992 v1.0.0. Zenodo. http://doi.org/10.5281/zenodo.3984875

Directories

|--exe # All compiled scripts are kept under here.
|--fort # F90 source code
|--fort_160129 # F90 source code
|--plate_boundary # Fault geometry data files are kept under here.
|--result # Setup file (.ctp), sample scripts, and plots of the result.
   |--data # Output files of the inversion analysis are saved.
   |--fwd # Input files of the inversion analysis should be kept here.
|--tmp # Where the temporary files created during inversion analysis are saved.

How to run geodetic inversion

Necessary script

gdinv.exe: The main script for running a geodetic inversion analysis.
This script is kept under /exe, and is the only script necessary for running inversion analysis (other scripts in /exe are not needed).

Necessary input files

1. Observation file (.dat): Input file of the coordinates and velocities of the observation points.
   The file should be kept under /result/fwd. (Sample file: /result/fwd/vel_data_YN.dat)

2. Fault geometry file (.cof): Input file of the fault geometry.
   The .cof file used in the inversion analysis should be kept under /result. (Sample file: /result/NE_gsi3.cof)

3. Setup file (.ctp): Setup file that contains inversion parameters and file names of the input/output.
   (See sample file /result/c0_inversion.ctp for details)

Sample script

There is a sample cshell script under /result that executes inversion analysis using sample observation data and setup file.

csh inversion.csh

Inside inversion.csh

$set ctpname = "c0_inversion.ctp" # Set the ctp file (sample: c0_inversion.ctp).

$../exe/gdinv.exe ${ctpname} # Geodetic data inversion analysis is executed,
                             # using the sample setup file (c0_inversion.ctp).

$sh plot_results.sh # Sample GMT (Generic Mapping Tool) script
                    # that plots the results of the inversion analysis.

For details of the Generic Mapping Tools, see http://gmt.soest.hawaii.edu/.

Results of the analysis

The result files of the inversion analysis are saved under /result/data directory.

res.scd # output file of the source displacement

res.cal # output file of the calculated displacements at the input observation points

res.fmp # output file of the B-splined source displacement

res_cal.dat # calculated displacements at the input observation points

res_obs.dat # observed displacements at the input observation points

res_o_c.dat # residuals of the observed vs calculated displacements

Results that are plotted

The plots of the results are saved under /result.

cnt_res.png # Contour map of the slip deficit rate.

scd_res.png # Vector map of the source displacement.

fwd_res.png # Vector map of the observed vs calculated displacements.

o_c_res.png # Vector map of the residuals of the observed vs calculated displacements.

Other scripts contained in this package

All compiled scripts are kept under /exe.

cgscd.exe # A script for scaling the output data,
          # used together with the sample GMT script (plot_results.sh).
          # This script has no effect on the result of the analysis.

mkscd.exe # A script that creates source displacement files from a given slip distribution data.

gdjacfw.exe # A script for calculating the Jacobian matrix of forward analysis.

gdfwd.exe # Main script for running forward analysis.

gdjac.exe # This script was used to calculate the Jacobian matrix for the inversion analysis,
          # but has been deprecated since the Jacobian matrix calculation was merged to gdinv.exe.

Source code

The source codes for the main program of inversion analysis (gdinv.exe) are under /fort_160129. The codes for other scripts (listed above) are kept under /fort.

Compiling the scripts

Makefiles of the scripts are under /fort and /fort_160129, and the bash shell script for running these makefiles are under /exe. When compiling all scripts, execute the command below.

$sh ./exe/compile.sh