SEISAN has several programs for extracting and writing out data for plotting or printing statistics, most of which will be listed in this section.
The program extracts parameter data from all header lines in a CAT file and rearranges the data in a table. In additions, there is an option to rearrange order and location of magnitudes on the header line. Below is an example of a run where the input CAT file is called collect.out :
report collect.out Below is shown parameters which can be chosen for output. A return will chose all, placing any character under a field will chose that parameter in the output. Each field starts with a capital letter and ends within the following blank. The order of the output can be changed by placing a number under the field and fields will be written out in the order of the numbers. E after time, lat, lon and dep are errors, L E is distance and event id s, F is both fix flags and A is agency for magnitude. The following example shows that Mc, Depth(Dep) and Time with error are selected and written out in given order. Date TimeE L E LatE LonE Dep E F Aga Nsta Rms Gap McA MlA MbA MsA MwA Fp Spec 30 45 20 10 Date TimeE L E LatE LonE Dep E F Aga Nsta Rms Gap McA MlA MbA MsA MwA Fp Spec x x x x x x x Number of output fields 8 Number of events 12 Number of events with spectra: 1 Number of events with fault plane solution: 3 Number of events with error estimates: 16 Number of events with mc : 10 Number of events with ml : 10 Number of events with mb : 8 Number of events with ms : 5 Number of events with mw : 12 Output report file is report.out Output nordic file is report_n.out Output of choices used in report.inp
The report.inp is a file with the choices used. Report can use that file (or a file with the same format and a different name) as second argument:
report collect.out report.inp
in order to use a fixed set of choices.
Content of report.out
Year Date Latitud Longitud Depth NST GAP Ml STRIK DIP RAKE 1996 6 3 47.776 153.222 0.1 12 348 1996 6 6 62.652 4.940 15.0 13 270 2.9 28 61 -41 1996 6 6 62.634 5.068 15.0 13 2.9 1996 6 6 62.652 4.940 15.0 13 270 2.9 28 61 -41 1996 6 7 59.841 5.127 12.0 12 1.9 8 41 75 1996 610 -13.481 167.130 200.1 301 1996 625 61.656 3.363 14.9 35 3.2 1996 7 5 61.282 4.825 7.1 10 2.0 1996 713 61.416 3.870 12.1 9 1.5 1996 718 60.156 2.070 15.0 9 1.8 1996 718 51.438 157.737 29.9 18 1996 726 61.755 2.293 22.1 9 1.8
The file report_n.out contains the input data with the only difference
that the magnitudes have been moved around on the header line. This
can be practical for later plotting with EPIMAP. If no magnitude
selection has been made, the magnitudes will come in the order Mc,
Ml and Mb. If no magnitude of that type is available, the output
field is blank. The magnitude selected
is the first to occur of the corresponding type. If other magnitudes
are to be selected, numbers can be used to select any 3 magnitudes
in any order. If it is important to select magnitudes by agency
also, use program MAG.
REPORT can also give a numbered output by adding the second or third argument
NORHEAD, making a compact Nordic file from a Nordic file
You must give arguments: First is input file, optional second is output file, if an optional second or third argument is -mag, magnitudes from following header lines are moved up to empty magnitude spaces on first line. The program was earlier called COMPACT (version 7.2 and earlier).
STATIS, statistics of databases
This is a simple program for making statistics of stations used in the database or in a file. The program will ask the following questions:
The output from the program could be as follows:
Station Local Ev. Local S. Distant E Distant S KONO 0 21 8 KMY 24 10 6 0 ODD 0 EGD 28 0 3 1 ASK 29 0 3 0 HYA 16 1 0 SUE 16 4 2 0 FOO 18 1 3 0 NRA0 86 9 0 MOL 38 17 14 1 NSS 9 6 7 0 MOR 0 LOF 25 13 12 0 TRO 12 2 13 1 BJO 0 KBS 3 2 8 6 JMI 16 0 KTK1 22 1 2 0 ARA0 66 6 0 NET NWAW NSN 147 JMI 21 KNN 10 W_L 2 W_E 1 W_S 2 Number of events selected with given stations 222 Number of events selected with more than --- 98 Number of events with no phases 0 Number of events with waveforms 168 Number of events with only waveforms 0 Number of events with 2 or more waveforms 9 Total number of waveform files 183 Total number of local events 200 Total number of regional events 0 Total number of distant events 34 Total number of events 234 Total number of records 2830 Output files are: statis.out statab.out (station statistics only)
The top part shows the event statistics by station. Local Ev is number of local events (readings if so specified above) (type L and R) at the station, Local S means number of local events ONLY recorded at that station, Distant E and distant S is the same for distant events (type D). The middle parts shows the number of waveform files NWAV from different networks NET as indicated by the first 3 letters of the waveform file name after the "." At the bottom is a summary statistics most of which should be self-explanatory. The information about ".. more than given stations" means that in addition to the stations searched for, the event had additional stations not used in the statistics.
This program calculates the yearly, monthly and daily number of events from a given earthquake catalogue and plots the results (written by Mario Villagrán). The input is a standard Nordic file containing only the header lines (compact file). The output is given in three different files with following default file names:
|catyear.out :||Output catalogue of the yearly number of events. This file contains two columns of data corresponding to year and the number of events.|
|catmonth.out :||Output catalogue of the monthly number of events. This file contains three columns of data, corresponding to the year, month and the number of events, respectively.|
|catday.out :||Output catalogue of the daily number of events. This file contains four columns of data corresponding to the year, month, day and the number of events, respectively.|
|cathour.out :||Hourly distribution of events within a day interval.|
In addition, a series of files with gmt in name give similar output for use with gmtxy (only Unix). The output files can then be used for plotting the histograms for the desired time interval at yearly, monthly or daily intervals. If desired, the corresponding histograms can be plotted interactively on the screen or can be printed. Several other routine programs such as grapher, xyplot, gnuplot or GMT, etc., can also be used for this purpose. The general purpose of this program is to evaluate the catalogue completeness. When run for different magnitude intervals, one can detect the magnitude thresholds above which the catalogue can be considered complete.
SWARM, finding earthquake swarms
The program is used to identify seismic swarms in a catalog. Input to the program is a CAT file with many events and some manually entered parameters. Output is identified swarms. The output file swarm.out contains all swarms organized as 'events'. In the header line is given the center for area identified and the 'magnitude' is the number of events in the area divided by 10. The rest of the line is information from first event in swarm.
Principle of selection:
The area is divided into a lat-lon grid. Around each grid point, there is a cell with radius small_r. The program first checks the number of events in each cell for the whole catalog. It then checks each cell to find which has more than the minimum number of events to constitute a swarm under the condition that enough events are within the required time window. For each time window, with enough events, a swarm is declared so a swarm lasting e.g. twice the time window will be declared as two swarms. An additional condition is that the number of events is larger than the normalized background activity. The normalized activity is calculated as the activity in the large cell normalized for area to the small cell, and normalized in time to the window for the swarm.
STATSTAT, number of events per seismic station in catalog
The program reads Nordic file input data and writes out text files giving the number of events per station.
LSQ, plotting a linear relation or a curve
A simple program to make and plot a least squares or maximum likelihood relation between
two parameters, plot a curve using the xy parameters or plot a hsitogram using the xy parameters. Input is from a file with two columns x and y. If a linear fit is made, the program also makes an output used with GMT in order to make nice plots. The PostScript output file is lsq.eps and the GMT file is lsq_gmt.out. In order to produce the GMT plot (only Unix), use command gmtxy lsq_gmt.out. The curve can be plotted with points only, lines joining the points with points plotted or just lines between points. X and y-axis for the curve plotting can be linear or logaritmic.
For plotting histograms, the input data must be equally spaced in x like e.g.
Examples of plots are found under program GETSTRESSDROP