NEIS is reporting the following earthquake in the Colorado
Rocky Mountains at 4:38 MST today.

2001/08/09 22:38:54 39.63N 107.35W ML=4.0 COLORADO

This is the largest event within 100 km of this epicenter
since Jan 7, 1971 (30+ years) when a Ml 4.3 occurred nearby.
It is also the first event of Ml>=3 within 100 km since a Ml 3.6
on April 2, 1997.

Since this is a 30-year earthquake for the central Colorado
Rockies, it must be considered a regionally significant event.

What is especially remarkable about this earthquake is
that three days ago in the far-field aftershock forecast
from the Pacific-Antarctic Ridge event (Mw 6.6), the
following observation (prediction?) was made:

"In the United States seismic events in Colorado often
follow earthquake in this area of the Pacific. "

and the possible location of a far-field event was noted in the aftershocks
of the September 1944 events as follows:
"Sept 3, 1944 57S 122W Mw 7.0?

==> Sept 9, 1944 Colorado 39N 107W Mb 5.0
This is one of the 3 largest earthquakes ever recorded
in Colorado."

This was the only other event in the area within 70 km of today's
event with Ml>=4.0.

Several artificial earthquakes in the Rangely area did exceed
this magnitude and may show up on an NEIS earthquake search. The
Rangely artificial earthquakes were an experiment in whether
artificial earthquakes could be induced by water injection. It
was thought that strain could be relieved in this manner avoiding
a larger event.

Any comments are welcome. I think the coincidence of the two largest
events in that region of the Pacific-Antarctic-Ridge and the two
largest earthquakes in this area of Colorado in especially interesting
in terms of earthquake prediction based on patterns.

And, no, Don, I did not feel this earthquake, did you Roger?

NEIS earthquake data at:

http://wwwneic.cr.usgs.gov/neis/bulletin/bulletin.html

P.S. Petra was a bit surprised that waves from as far away as the Antarctic
could trigger earthquakes in Colorado - but that was two days ago (in e-mail)
What do you think now, Petra?