Magnitude 6.8 near Seattle, WA

Information from the NEIC/USGS Golden
Location: 10.9 miles / 17.6 km NE of Olympia, WA	47.1525 N     -122.7197
Date & Time (Local):	2001/02/28 10:54:33
Date & Time (UTC):	2001/02/28 18:54:33
Depth (km):	52.4
Mw (preferred):	6.8
ML:	6.3

The following is from the United States Geological Survey, National Earthquake Information Center:

The following is a revised REPEAT revised release by the United States Geological Survey, National Earthquake Information Center: Preliminary hypocenter for earthquake of 2001 Feb 28, WASHINGTON, about 10 miles (20 km) NE of OLYMPIA, Washington: latitude 47.2 degrees north, longitude 122.7 degrees west, origin time 18 54 33.0 utc, depth 52 km, magnitude 6.8. The magnitude has been revised based on further processing of available data. The preliminary mechanism for this earthquake is tensional (normal) faulting in the subducting (downgoing) Juan de Fuca Plate, caused by bending of the plate. Damage and injuries have occurred in the Olympia-Seattle area. The earthquake was felt as far away as Salt Lake City. This earthquake is located in the same general area as a magnitude 7.1 earthquake on April 13, 1949. In terms of energy released, today's earthquake is about one-third as strong as the 1949 quake. The location for this earthquake was furnished by the Geophysics Program, University of Washington, Seattle.

• Details
  • UCB Moment Tensor
    • Preliminary moment tensor based on data from YBH
    • Revised moment tensor showing depth resolution
  • Special Event Pages - Seismological
    • University of Washington
    • USGS
    • IRIS
  • Special Event Pages - Engineering
    • University of Washington
    • Pacific Earthquake Engineering Research Center
    • Earthquake Engineering Research Institute

• Seismograms
  • Seismogram from WDC LHZ via "Make Your Own Seismogram"
    WDC is one of many BDSN stations that recorded this earthquake. Note the earlier event in the Loyalty Islands.
  • Seismogram from CMB
  • BDSN record section

  • A tracing in sand from a pendulum in Port Townsend, WA

• Maps
  • Recenteqs map for Seattle
  • Seattle-area earthquakes 1960-2001
  • Cross-section view of Seattle seismicity
    This figure shows a depth slice of the seimicity. The line of earthquakes growing deeper to the east (toward the right hand side of the figure) are in the Juan de Fuca plate, which is subducting under the North American plate. The 02/28/01 earthquake occurred in the Juan de Fuca plate.
  • Map and cross sections of Washington seismicity
    The map view shows ~30 years of earthquakes as reported in the CNSS catalog, along with the approximate location of the Juan de Fuca/North American plate boundary. The blue lines mark the slices for the depth cross-sections and the green circle indicates the location of the 02/28 event. The cross sections show the seismicity in the Juan de Fuca plate as it subducts under North America. Other examples of subduction zone seismicity are available. Special thanks to David Dolenc of UC Berkeley for these figures.
  • Map of Western US plate boundaries
  • 3D visualization of the Seattle earthquake

• Ground shaking information
  • Map of strong ground shaking - aka ShakeMaps
  • Community Internet Intensity Maps - see what other people felt and report your observations!

• Links to other resources
  • The Seismology of megathrust earthquakes from the Geological Survey of Canada
  • Seismic Hazard Map for Washington and Oregon from the USGS
  • Earthquake History of Washington from the USGS
  • Earthquake History of Cascadia from the University of Washington
  • Earthquake Hazards in Oregon and Washington from the University of Washington
  • FAQ on EQs in Washington and Oregon from the University of Washington
  • EQ Hazards in the Portland-Vancouver Area from the USGS