Pacific Northwest Seismograph Network Operations
1434-95-A-1302
S.D. Malone, R.S. Crosson, and A.I. Qamar, P.I.s
Dept. of Earth and Space Sciences, University of Washington
Seattle, WA 98195
Phone:(206)543-8020 FAX:(206)543-0489
e-mail: steve, bob, tony, or ruth@ess.washington.edu
Key words: Seismology, Education-lay, Real-time earthquake information
Oct. 1, 1995 - Sept. 30, 1996
Non-Technical Summary
Operation of the Pacific Northwest Seismograph Network (PNSN)
and preliminary analysis of earthquakes in Washington and Oregon
continues under this agreement. The PNSN operates 85 stations
west of 120 degrees west longitude under this agreement, and 58
additional stations under other support. In addition to network operation, the
PNSN conducts an educational outreach program on
seismicity and natural hazards.
Our web-site is located at:
/SEIS/
The PNSN
processed 5,041 events between Oct. 1, 1995 and Sept. 30, 1996.
Of these, 4,129 were earthquakes or blasts within the network
(1,297 of which were too small to locate). Within our network
area, 2,288 earthquakes were located west of 120.5 degrees west
longitude (including 623 near Mount St. Helens, which has not
erupted since 1986), and 140 east of 120.5 degrees west longitude.
The remaining events were blasts within the network, regional
earthquakes (266) or teleseisms (646).
Thirty-two earthquakes were reported felt west of the Cascades
in Washington, ranging in magnitude from 2.2 to 5.3,
and one earthquake (magnitude 3.1) was felt east of the Cascades.
The Duvall Earthquake:
The largest earthquake during this reporting period was the magnitude
5.4 Duvall earthquake of 3 May 1997 at 04:04:23 UTC
(2 May 1997 at 9:04:23 PM PDT). The epicenter was located at about 7 km depth
in the Cascade foothills, about 35 km east-northeast of Seattle and
9 km east-northeast of Duvall. In addition to the mainshock, 22 aftershocks
were reported felt. Information on the Duvall earthquake is available through a
PNSN
Duvall web-page:
(/SEIS/EQ_Special/Duvall/).