Next: 10.5 GMAP, Plotting epicentres with Up: 10. Plotting epicenters Previous: 10.3 W_EMAP, Version Windows based Contents Index
The program can make a standard GMT plot of epicenters, stations, ray traces and fault plane solutions. The input can be standard input from a file, data base or index file. All scaling is done automaticallyi. 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
mapg select.out
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
-s or -S: as above with station file following
f: plot fault plane solutions, size proportional with magnitude
F ————————–, size constant
-m: plot epicenter symbol with constant size, default is proportional to magintude optionally add size in cm
l: plot localities names
L: plot localities with names and symbols
R: plot rays
t: no topography
u: user gives area, question asked later
e: do not plot epicenter
rf, rh, rl or rc: high to low resolution
c: do not plot coast line
-c: fill landmass with color from next argument e.g. -c blue
The rays are generated from the stations in the S-files. Only stations with given phases are used and only with given weights so e.g. all P-phase rays can be plotted. The epicenter coordinates are taken from the S-files and the station coordinates from the STATION0.HYP. The additional question is:
Enter phases to use for ray paths, one per line, terminate with enter Only the chars given will be used so entring e.g. P, all P-type phases will be used
P
Minimum output weight for phase-stat to be used, enter for non zero weight phases
When using the R -option, epicenters are always plotted, also epicenters without rays. Stations are only plotted if s or S options is used and only the stations used are plotted. The map outline is adjusted to include all stations used. The ray paths in GMT format are stored in file mapg.ray.
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. In Windows, a free software pstopdf and be used to convert to PDF so the command could be the following commands put into a BAT file.
pstopdf -i
figure.pdf
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
GMT_LOCALITY_FILE, see above. Format is the same as otjher locations files in SEISAN. Latitude, longitude and name, 2f12.3,a
MAP_LAT_BORDER and MAP_LON_BORDER, the same a sfor EPIMAP, distance to map center (deg) when only one epicenter.
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 t.out R
Options, some by interactive input or as arguments
The first argument is filenme so e.g. mapg select.out f l
s: plot stations as triangles
S: --------- with station code above
-s or -S: as above with station file following
f: plot fault plane solutions, size proportional with magnitude
F --------------------------, size constant
-m: plot epicenter symbol with constant size,
default is proportional to magintude
optionally add size in cm
l: plot localities names
L: plot localities with names and symbols
R: plot rays
t: no topography
u: user gives area, question asked later
e: do not plot epicenter
rf, rh, rl or rc: high to low resolution
-c: fill landmass with color from next argument
e.g. -c blue
Enter phases to use for ray paths, one per line, terminate with enter
Only the chars given will be used so entring e.g. P, all P-type phases will be used
P
S
Minimum output weight for phase-stat to be used, enter for non zero weight phases
1996 0606 0648 27.2 L 62.916 4.491 34.3 BER 6 .30 3.2LBER 2.6CBER 3.0LNAO
1996 0606 0648 35.5 L 62.658 5.449 0.00 BER 9 3.3 3.1LBER 3.0LNAO
1996 6 6 649 2.8 L 60.678 3.180 15.0 BER 6 5.8 2.1LBER 2.6WBER 3.0LNAO
1996 0607 1325 37.3 L 60.899 4.782 12.0F BER 3 6.2 3.4LBER
1996 6 7 1325 37.3 L 60.899 4.782 12.0F BER 3 6.2 3.4LBER
1996 0625 0337 33.6 R 61.595 3.730 0.00 BER 12 .20 4.9CBER 3.2LNAO
1996 625 337 38.9JL 61.476 3.952 1.60 BER 9 1.9 3.4LBER 2.7SBER 3.2LNAO
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: 7
Number of events with fault plane solution: 3
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 7
Number of events with location 7
Lattitude range to use 59.0 63.3
Longitude range to use 2.4 8.0
Grid size in lat and lon: 1.00 2.00
c:\seismo\WOR>pstopdf -i mapg.ps -o figure.pdf
c:\seismo\WOR>figure.pdf
Number of events in input file or data base 7
Number of rays generated 36
Number of stations used for rays 10
File with ray paths is mapg.ray
File with stations used for rays is gmtstxy.out
Output of events in input file with location: mapg.out
Output of postscript file with map: mapg.ps
Output of gmt script: mapg.gmt
c:\seismo\WOR>
Normally the size of the plot in lat long is determied from the data in the epicenter file. However, the u-option can override that and the user is asked for lat lon range. An alternative station file can be given with option -s or _S so specific stations can be plotted instead of the stations corresponging to the content of the CAT file. Whhen option e is used, the map is sclaed by the epicenters is CAT file, but not plotted so this option can be used to plot only stations.
NOTE: first argument is ALWAYS a CAT file, whether used or not.
If an input CAT file is only header lines, station names and cocrdinates must come from a separate file.
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. An example 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 #.
![\begin{figure}
\centerline{\includegraphics[width=0.9\linewidth]{fig/mapg}}
\end{figure}](img105.svg)