Roger:

You can get a list of faults and their coordinates here:

http://geohazards.cr.usgs.gov/eq/html/faults.shtml

The listing is by state. Hope this helps. (Click the link).

This standard CA quake map would be the ideal map to use, IMO. It is found (as you know) at:

http://www.scecdc.scec.org/recenteqs/

It has the underlying lat/long coordinate system embedded in it and the fault lines also showing as well.

One way to get a grid overlay would be to ask the USGS for assistance by way of email for the CA map(?!) The other way is to skip the lat/long grid overlay altogether and just use the fault line lat/long file internal to check for a fault line intersection (with range ring). If one is found then you would plot the fault again overlaying it with perhaps a different colored line (if that's something that is do-able in True Basic) or just add an "X" or other icon to the map to indicate the intersection. Is that within striking range Roger ?

Meanwhile, it you modified the ring-map program to produce a text file which justs lists which fault lines are being intersected (using the lat/long per fault line in a search mode looking for intersections) then this could be used in the short-term. I would call any range ring which gets closer than 10-25 km or so a "hit" in this regard.

This will allow you to continue to battle the software, etc. to get things working perfectly while still providing this output in a non-graphical format (text file).

One other point is that the CA map at the link above can be converted to a BITMAP (*.bmp) file and then directly edited (with a program...ring-map subroutine?) with a utility which adds the ring trajectories. Since it already has the fault data embedded in it...it's a quick Slam-Dunk ....

Go get 'em Roger

.02

• Fault coordinates by state