The program can make a standard GMT plot of epicenters, stations and fault plane solutions. The input can be standard input from a file, data base or index file. All scaling is done automatically Both standard s-files and compact files can be input. If the program is started without argument, it will ask for input data and whether stations and/or fault plane solutions should be plotted. The program uses the standard SEIGMT program to prepare the data for GMT and the stations plotted are therefore the stations found in the input data and not all possible stations in the area. The program can also be started with input on the prompt line, but then only with input from a file like
With input from the prompt line there is also more options like
mapg select.out f s
which will plot fault plane solutions and stations. All options are:
s: plot stations as triangles
S: ------------- with station code above
f: plot fault plane solutions, size scaled with magnitude
F: -------------, fixed scale
m: plot epicenter symbol with constant size, default is proportional to to magnitude
The output is a PostScript file mapg.ps and a script file mapg.gmt. The script file can be used to do modifications to the plot that is not possible with the program. Some modifications are obvious but others require knowledge of GMT. On Linux, the file can be executed by command 'source mapg.gmt'. On windows, rename file to e.g. m.bat and execute by typing 'm'. Do not use name mapg.bat since the program would no longer run by using the mapg command, only the script if started from directory with the script.
Some parameters for the program is set in SEISAN.DEF:
PLOT_PS_COMMAND: The command used for displaying the ps file, usully GhostScript. GMT_GRIDFILE: The GMT grid file used. A reasonably detailed world file is found at ftp://ftp.geo.uib.no/pub/seismo/SOFTWARE/GMTEXAMPLES/DATA/newbathy.grd
The map projection is hardwired to Mercator. The maximum horizontal size is 17 cm. The horizontal size will be reduced if the vertical size is more than 1.5 times the horizontal size. The minimum lat-lon division is 0.25 deg. The title is hardwired to Epicenters, can be changed in script.
The program uses latest version of GMT.
An example run is c:\seismo\WOR>mapg select.out s F 1990 1213 1109 19.8 LE 60.328 5.167 0.0F BER 6 1.3 0.9CBER 1995 822 0141 6.2 L 60.389 2.597 30.3 TES 13 0.7 2.3LTES 2.7CTES 2.2LNAO 1995 1120 0401 59.1 L 60.052 5.402 1.5 TES 12 0.5 2.0LTES 2.3CTES 2.1LNAO 1996 6 6 0648 30.4 L 62.636 5.050 15.0 TES 13 0.9 2.9LTES 3.0CTES 3.0LNAO 1996 6 7 1325 29.2 L 59.846 5.130 12.0F TES 12 0.6 1.9LTES 2.2CTES 2.0LNAO 1996 625 0337 32.9 L 61.587 3.496 15.2 TES 31 1.0 3.2LTES 3.0CTES 3.2LNAO 1996 7 5 0220 46.5 L 61.287 4.829 8.0 TES 10 0.4 2.0LTES 2.2CTES 1.9LNAO 1996 713 0556 46.0 L 61.419 3.872 12.2 TES 9 0.5 1.5LTES 2.1CTES 1.6WBER 1996 718 0946 51.4 L 60.158 2.070 15.0 TES 9 1.1 1.8LTES 2.5CTES 2.1WBER 1996 726 0742 12.0 L 61.756 2.316 20.8 TES 9 0.4 1.8LTES 2.4CTES 2.0WBER 1997 812 0814 24.1 L 59.818 6.646 12.0F TES 14 0.6 2.8LTES 2.7CTES 3.4LNAO 1999 529 0031 43.6 L 62.201 4.587 15.0F TES 32 0.7 3.9LTES 3.2CTES 3.8LNAO 2000 2 1 1242 20.2 L 61.606 4.693 0.0 TES 13 0.7 2.3LTES 2.1CTES 2.3LNAO 2000 210 0617 57.4 L 61.760 4.539 6.0F TES 20 0.7 3.6LTES 2.9CTES 3.3WBER 2000 210 1740 7.2 L 61.847 4.414 2.4 TES 16 0.7 3.0LTES 2.5CTES 3.0LNAO 2002 411 1316 27.9 LE 58.202 6.203 0.0F BER 7 0.9 1.8LBER 2.0CBER 2004 5 2 1924 53.9 L 59.893 6.271 5.0F TES 16 0.9 1.5LTES 1.3CTES 2.0LNAO 2004 511 0050 47.7 L 60.017 5.305 7.0F TES 16 0.7 1.8LTES 1.7CTES 2.3LNAO 2004 7 5 1809 36.9 L 57.505 7.139 15.0FFDNK 5 1.0 2.2LDNK 1.9CDNK End of s-file Grid file to use: c:\a\gmt\newbathy.grd Nordic input file Return to use largest magnitude, or enter magnitude order (e.g. CLBSW) scale: size = mag * scale (for example 0.01) Input file is Nordic. Number of events: 19 Number of events with fault plane solution: 6 epicenter location input file for GMT psxy/psxyz: gmtxy.out/gmtxyz.out epicenter locations with day counter from first event gmtdays.out station location input file for GMT psxy: gmtstxy.out time and magnitude to be used with GMT psxy: gmttime.out travel path input file for GMT psxy (option -M): gmtpath.out Coordinates are given as longitude - latitude input file for psmeca (Aki and Richards convention): psmeca.out Number of events in input file 19 Number of events with location 19 Lattitude range to use 57.0 63.1 Longitude range to use 1.5 7.6 Grid size in lat and lon: 2.00 2.00 psmeca: Number of records read: 6 Number of events in input file or data base 19 Output of events in input file with location: mapg.out Output of postscript file with map: mapg.ps Output of gmt script: mapg.gmt
Most of the output is self explanatory. Only events with locations are used so number of events plotted might be different from number of events in input file. The events used are output in mapg.out. The plot is seen in Figure 10.4.
The script file (Windows) corresponding to the above run is:
REM REM Set font, size and color of title REM gmt gmtset FONT_TITLE = 14p,Helvetica,black REM REM Cut out desired area from grid file, area is 1.500/7.600/57.00/63.100 REM gmt grdcut c:\a\gmt\newbathy.grd -R1.500/7.600/57.00/63.100 -Gmapg.grid REM REM Make color table, global colors REM gmt makecpt -Cglobe -T-8500/8500/50 -Z > mapg.cpt REM REM Plot base map, midpoint is 60.05/4.55/ horizontal size in cm is 07 REM Longitude and latitude grids are: 2.00 2.00 REM gmt psbasemap -Bxa002.00g002.00 -Bya002.00g002.00 -B+t"Epicenters" -JM60.05/4.55/07c -R1.500/7.600/57.00/63.100 -K -P >mapg.ps REM REM Compute directional gradients from a grid REM gmt grdgradient mapg.grid -Nt1 -A225 -Gmapg.gradient REM REM Make the map REM gmt grdimage -JM60.05/4.55/07c -R1.500/7.600/57.00/63.100 mapg.grid -Imapg.gradient -O -K -Cmapg.cpt >> mapg.ps REM REM Plot coast line REM gmt pscoast -JM60.05/4.55/07c -B -R1.500/7.600/57.00/63.100 -Dh -N1/1.00p,- -K -O -W >> mapg.ps REM REM Plot epicenters, size proportinal to magnitude REM gmt psxy gmtxy.out -R -J -Sc -G200/0/0 -W0.3 -O -K >> mapg.ps REM REM Plot stations, blue triangles, size 0.4 REM gmt psxy gmtstxy.out -R -J -St0.4 -Gblue -W1 -O -K >> mapg.ps REM REM Plot fault plane solutions, -1 to avoid date on top of REM of fps, 1.0 is size proportinal to magnitude, to make REM fixed size, add parameter -M REM gmt psmeca psmeca.out -R -J -V -Sa1.0/-1 -M -P -O >> mapg.ps REM REM REM REM Plot map on screen REM gswin32 mapg.ps
In Linux REM is replaced by #.