NEWS ITEM - June 30, 2004

LATEST UPDATE ON EARTHQUAKE ACTIVITY NEAR LAKEVIEW, OREGON

An earthquake sequence is currently occurring near Lakeview, Oregon. The first event in the area was located on June 4, and picked up on June 25, with 6 located events. The sequence continues to accelerate, and a magnitude 4.4 earthquake occurred at 5:22 AM June 30, 2004.

These earthquakes lie in an area where seismicity is infrequent, and there are few stations nearby. This area is also between the Pacific Northwest and California networks, so two different groups are providing data and analysis. The PNSN and California Integrated Seismic Network are exchanging data for these events.

The apparent north-south alignment seen in our standard network locations is most likely due to location errors because of the limited data. A careful relocation of some of the larger earthquakes suggests that the events likely originate fairly close together. A PDF Map - from Oregon DOGAMI shows the relocation of the best-constrained earthquakes with topography and faults. The earthquakes do not appear to lie on the Goose Lake Fault, which dips to the west. Fault maps of the area may be incomplete, or the fault producing these earthquakes may not reach the surface.

  • Frequently updated list of earthquakes in the sequence
  • Frequently updated map of the sequence - Most recent earthquakes highlighted
  • Additional details on the sequence - from PNSN
  • Additional Details - from California Integrated Seismic Network - Includes focal mechanisms, which indicate normal faulting, as is typical in the Basin and Range area.

    A previous sequence in this area (near Adel, Oregon in 1968) included twenty earthquakes of magnitude 4.0 or larger, with two of them magnitude 5.0 or above. Based on the geology of the area, and its previous history, we consider it possible - and probable - that the currrent sequence will continue, and may produce larger earthquakes.

    Links 

    
 Warner Valley Oregon Sequence, May-June, 1968
From: Couch, R. and Johnson, S., 1968, The Warner Valley Earthquake Sequence,
May and June of 1968, The Ore-Bin, v. 30, #10, pp. 191-204.

    
 DATE-(UTC)-TIME   LAT(N) LON(W)   DEP  MAG QUAL COMMENTS
yy/mm/dd hh:mm:ss   deg.   deg.    km   Ml
1968/05/28 00:08:48  42.25N 119.66W  21.0 4.4   19.4 km ENE of Adel, OR
1968/05/28 00:51:03  42.25N 119.76W  33.0 4.1   12.5 km  NE of Adel, OR
1968/05/28 12:55:42  42.25N 119.80W  34.0 4.4    9.3 km  NE of Adel, OR
1968/05/30 00:35:58  42.33N 119.84W  22.0 5.1   15.7 km NNE of Adel, OR
1968/05/31 03:06:38  42.09N 119.77W  33.0 4.1   14.6 km  SE of Adel, OR
1968/06/03 13:27:39  42.25N 119.80W  20.0 5.0    9.9 km  NE of Adel, OR
1968/06/04 02:34:14  42.24N 119.87W  25.0 4.6    5.6 km NNE of Adel, OR
1968/06/04 02:38:29  42.31N 119.78W  25.0 4.0   16.2 km NNE of Adel, OR
1968/06/04 03:35:49  42.31N 119.75W  33.0 4.1   18.0 km  NE of Adel, OR
1968/06/04 05:52:32  42.28N 119.81W  34.0 4.0   12.2 km NNE of Adel, OR
1968/06/04 06:22:17  42.20N 119.83W  26.0 4.4    5.2 km   E of Adel, OR
1968/06/04 10:58:22  42.25N 119.76W  25.0 4.2   12.6 km  NE of Adel, OR
1968/06/05 04:51:56  42.22N 119.98W  25.0 4.6    9.1 km WNW of Adel, OR
1968/06/05 05:12:35  42.29N 119.76W  33.0 4.4   15.6 km  NE of Adel, OR
1968/06/05 07:37:45  42.25N 119.91W  33.0 4.0    6.7 km NNW of Adel, OR
1968/06/05 08:20:38  42.29N 119.83W  33.0 4.0   12.0 km NNE of Adel, OR
1968/06/12 01:46:21  42.13N 119.79W   8.0 4.3   10.9 km  SE of Adel, OR
1968/06/21 20:33:27  42.20N 119.65W  23.0 4.3   20.1 km   E of Adel, OR
1968/06/22 09:39:52  42.18N 119.72W   0.0 4.3   14.3 km   E of Adel, OR
1968/06/24 11:03:17  42.29N 119.83W  33.0 4.2   11.7 km NNE of Adel, OR