LATEST UPDATE ON July 12, 2004 Magnitude 4.9 Offshore Oregon Earthquake

Monday July 12, 2004 at 09:45:0.41 AM (PDT), a magnitude 4.9 earthquake occurred off the coast of Oregon, about 50 km southwest of Newport Oregon. The earthquake was felt by many people along the coast.

More Info - from the PNSN More info - from the USGS

The distribution of stations near this earthquake is not optimal and the location quality is poor, but our location for this earthquake places it at a depth of about 29 km, placing it within the mantle beneath the subducting Juan de Fuca plate. The focal mechanism indicates a combination of normal and strike-slip faulting along a northwest-southeast striking fault. Faults of similar orientation are known to break the surface in this offshore area, but whether these faults could extend to depths as great as 25 km is unknown, and seems improbable. A map showing historic earthquakes and mapped faults in Oregon is available from DOGAMI

Historic seismicity in this area is sparse, but a magnitude 5.0 earthquake did occur not far away in 1960:

From: United States Earthquakes, 1960
By H. Carroll Talley, Jr. and William K. Cloud, 1962, U.S. Department of
Commerce, Coast and Geodetic Survey, U.S. Government Printing Office, pp.
27-29.

November 8: 03:36:27.2*. Epicenter 45.1 degrees
        north, 125.2 degrees west, about 50 miles off coast of
        Oregon, W. Reported felt with moderate in-
        tensity at scattered communities along the
        coastal areas of Washington and Oregon, from
        Aberdeen and Montesano, Grays Harbor County,
        Wash., south to Yachats, Lincoln County, Oreg.,
        a distance of approximately 185 miles. In
        Oregon, it was felt inland to distances of about
        35 miles. Maximum intensity (damage) IV.
   INTENSITY (DAMAGE) IV IN OREGON: Agate
        Beach, Alpine, Alsea, Buxton, Nashville, New-
        port, Rockaway, Tidewater, Toledo, and Yachats.
   INTENSITY (DAMAGE) IV IN WASHINGTON:
	Ilwaco and Long Beach.
   INTENSITY (DAMAGE) I TO III IN OREGON: Can-
        non Beach, Corvallis, Depoe Bay, Hammond,
        and Umpqua.
   INTENSITY (DAMAGE) I TO III IN WASHINGTON:
        Aberdeen and Montesano.