MILD EARTHQUAKE HITS NORTHERN IDAHO/WESTERN WASHINGTON

An earthquake of Ml 3.4 (PNSN) occurred today near the northern
Idaho/Washington border. PNSN gives the following parameters for
this and a series of aftershocks:

ML=2.3 2001/06/25 09:49:16 47.739N 117.472W 0.0 SSE of Colville, WA
ML=2.8 2001/06/25 08:06:06 47.710N 117.447W 0.4 SSE of Colville, WA
ML=2.8 2001/06/25 08:01:26 47.671N 117.428W 5.0 (not available)
ML=3.4 2001/06/25 07:15:21 47.650N 117.434W 5.0 (not available)

This is in the same general vicinity as the location cited in an
earthquake prediction Don made to this board last week regarding the
possibility of an earthquake within 40 km of Coeur d'Alene Idaho located
in Northern Idaho near the Washington border.

Historically, earthquakes in an area including both the epicenter and
the forecast epicenter (limited by 47N - 48N and
118W - 116W) do not occur often in the Ml>=3 range. In fact, this is
the largest event in this region since a Ml 5.0 on Dec. 19, 1957.
There have been only 13 earthquakes in this region since 1900 with
Ml>=3, about one every 8 years. The last occurred in March 1999 (Ml 3.1).

In evaluating Don's prediction, it is necessary to give him credit
for identifying the locale of an unusual earthquake within several
days of that earthquake's occurrence, even if the exact parameters
of the earthquake fall outside his predicted range. I'm sure
Don would agree with credit for a near miss on this one - how's
that bullseye scoring system work on this one, Roger?

That said, Don's prediction was:

Earthquake Forecast For Coeur d'Alene area, ID
Posted by Don in Hollister on June 14, 2001 at 22:43:18:

Magnitude: 2.0-3.0
From: 06/18/2001 - To: 06/23/2001
Location: Coeur d'Alene area, ID
Lat: 47.257N - Long: 116.281W - Range: 40

Hi All. The old tummy is rumbling tonight so I listened to it to see if it
was trying to tell me something. Getting mixed signals. Not sure if its
something I ate, or something I'm going to eat. Mainly my words.

Looking for a 2.0Md to a 3.0Md at 47.257N/116.281W in the Coeur d'Alene area,
ID on 06/20/2001. Radius 40K starting on 06/18/2001 through 06/23/2001.
Take Care...Don in creepy town.

This earthquake is about 1 day later than the predicted time frame,
the mainshock is larger than expected, although the aftershocks
fall in the predicted range, and the epicenter is about 80 km from
the predicted epicenter whereas Don's estimate of closeness was
40 km.

Clearly, this is a miss, but a near miss on a very unusual
earthquake. I would have to agree that scoring for near misses
is justified in a case like this.

By the way, data for the period Jun 18 through Jun 23 2001 is still
not available for this area, so it is still possible that an event
will be listed which is within Don's parameters.

For further information on today's events see:
http://www.geophys.washington.edu/recenteqs/Quakes/quakes0.html

P.S. Any relationship between this and the Peru event has yet
to be determined.

• Earthquakes in the Pacific Northwest