Quake View (QUAKEVU) 
Seismic Display Software for the PC

Version 7
January, 1998

Ted Blank
954 Foxswallow Ct.
San Jose, CA 95120

ted_blank@pobox.com


Disclaimer
The software in this package is provided free of charge for non-commercial purposes only.  It 
may be copied and redistributed without restriction.  Please report all bugs to the author.  This 
documentation is distributed with version 7 of the software.  

What is QUAKEVU?
The QUAKEVU program displays the quake files captured by EMON or SDR. It uses the Color 
Graphics Adapter (CGA) in high resolution (640x200) mode. This is equivalent to SCREEN 2 in 
IBM BASIC.   QUAKEVU requires only DOS 3.1 or higher and about 320K of memory, so it 
should run on almost any PC that supports even basic graphics.
QUAKEVU is a part of the EMON package which is available from the PSN web site, 
http://psn.quake.net.  The EMON package provides a full set of software to record seismic 
activity on a PC running only DOS.  QUAKEVU is the file viewer for the EMON package, but it is 
packaged here separately for the convenience of people who only wish to view existing files.
What is the difference between QUAKEVU and WinQuake?
WinQuake by Larry Cochrane is a full-function quake file viewer with many more features than 
QUAKEVU.  However, it requires Windows and therefore more memory and more powerful 
processors.  WinQuake is also available from the PSN web site.
Contents of the QUAKEVU package
The following files are contained in this package.
File Name
Description
QUAKEVU.EXE
Displays data files on CGA graphics screen; 
computes P-S interarrival time and distance; 
allows user to enter comments
QUAKEVU.INI
Initialization file for QUAKEVU.  Edit this file with 
any text editor which does NOT insert tab 
characters to customize how QUAKEVU starts.
971204AE.FOX
Sample data file used for examples in this 
document.
EL.EXE  (EmonList)
Displays list of quake data files in any directory;  
allows you to invoke QUAKEVU from a full screen 
menu.
HOWFAR.EXE
Program to compute great circle distance between 
any two points on the earths surface given their 
latitude and longitude.
HOWFAR.LOC
File containing your stations latitude and longitude; 
saves you typing this information in every time you 
use HOWFAR program.
Table 1
Note: If you are running QUAKEVU under DOS version 3.1 or higher, you must issue the DOS 
command GRAPHICS or GRAFTABL once each time you power-on or re-boot the machine. If 
you do not execute this command before running QUAKEVU, the screen will look very strange 
with lots of fuzzy square characters in the menus. DOS began to require this in version 3 as part 
of their support for languages other than English. If you find you have this problem, the simplest 
solution would be to add a line with the proper command to your PCs AUTOEXEC.BAT file. 
QUAKEVU will remind you when it starts if you need to run the GRAFTABL command but have 
not done so. 
QUAKEVU features
Functions supported by QUAKEVU are: 
  Multiple files from the same event (from the same or different recording stations) can be 
displayed simultaneously 
  Mouse support with pull-down menus 
  Online help 
  Variable scale, on both X (Time) and Y (Amplitude) axes 
  Interactive P- and S-wave identification via graphic pointers 
  Automatic epicenter distance and travel time calculations as the P and S pointers are moved 
  Expanded view (zoom) on a subset of the data in a file 
  Ability to create a new data file containing only a subset of data in the original file (and a 
comment if you wish) 
  Connect data points with lines, or plot as points only 
Mouse Interface to QUAKEVU
If your PC has a mouse, you can use it to do all of the above functions via pop-down menus. 
Several pop-down menu items list a keyboard function key (like F1 or F2) that does the same 
thing as the menu bar. You can use either one. 
Arrow keys while Zoomed
If you are zoomed in on a small section of a file, you can use the left and right keyboard arrow 
keys to move left and right through the file. Each keypress moves one screen left or right. 
Further help is available in the program. Enter QUAKEVU ? for details or select HELP while 
running the program. 
Printing the screen from QUAKEVU
Use the Shift-PRTSC key to print the screen if you want to save a hard copy. However, the DOS 
Print Screen function prints only in character mode and QUAKEVU runs in graphics mode. 
Luckily, DOS supplies a command called GRAPHICS which takes care of this problem. Execute 
the GRAPHICS command once each time you power-on your PC. Once you run this command, 
the Print Screen key will print your QUAKEVU screens properly. As with the GRAFTABL 
command the easiest solution may be to add the GRAPHICS command to the AUTOEXEC.BAT 
file of the PC where you usually run QUAKEVU. 
QUAKEVU example
We will use QUAKEVU to examine a recording of a recent earthquake recorded in San Jose, 
California.  We issue the command QUAKEVU 971204AE.FOX, and we see the following 
screen:
 
We can now see for the first time the actual earthquake record.  You can see at the left the 
baseline signal, then the arrival of the P waves and later the arrival of the S waves.  (The L 
waves are off the recording and were recorded in the next file).  
Now lets tell QUAKEVU where we think the P and S wave arrivals are.  We click on Distance (or 
press F2) which brings up the next screen.  
 

We move the P pointer to the arrival of the first P wave (using the left and right arrow keys or the 
mouse).  Notice that the time of arrival of the P wave is updated as we move the pointer.  
 
QUAKEVU cannot compute the distance to the quake until we provide it with an estimate of 
when the S wave arrives so lets do that.  Select Distance (or press F2) again and the S pointer 
appears.  Move it to the arrival of the S wave.

Now that the P and S wave arrival times are both identified, QUAKEVU can compute the 
estimated distance from the recording station to the quake location.  Notice that as you move the 
P or S pointers, the estimate of distance changes.
You can fine tune the placements of the P and S waves by selecting Distance again (or pressing 
F2).

Saving a subset of the original file
You can use  File/Save (F8) to save a smaller size file containing only the portion of the original 
file currently being displayed.  Select File/Save (or press F8) and you will be prompted to specify 
up to 7 characters of a file name. (The 8th character and the file extension are copied from the 
original file name).You can enter names like the following:
a:* 		Saves file on a: drive with same name as large file 
b:myquake 	Saves file as b:myquake.lll (where lll is station ID) 
\quakes\* 	Saves file in QUAKES directory with same name  
myquake 	Saves file in current drive/directory as myquake.lll 
* 		Replaces input file (large) with subset file (small)
Printing the screen contents
You might want to print what is on the screen to have a hard copy for your files. To print the 
screen contents, you must have issued the DOS command GRAPHICS in the DOS session 
before entering QUAKEVU. This command tells DOS that all future PrintScreen key presses 
should assume the screen is in graphics mode (like QUAKEVU uses), rather than just as text. If 
you did not issue the GRAPHICS command before invoking QUAKEVU, you can do so now via 
the DOS Command key. Then just press the Shift-PrtSc key and DOS will print your screen 
image on the printer. Note - some laser printers will not properly print this type of screen. You 
may have to use an old-fashioned dot-matrix printer or some other type of screen-capture 
program. 

