Felt in western Washington and from southern British Columbia to northern Oregon and east to Wenatchee.

Maps
• Regional Map of mainshock area and first-motion focal mechanism.
• Local Map of mainshock and first month of aftershocks (355 located > Mag 1.0).
• Very Close Map of all earthquake locations through July 22, 1996.
• Map showing the 1996 Duvall earthquake in relation to other historical shallow earthquakes in the Pacific Northwest.

Seismicity Plots and Aftershocks

• Seismic Activity at Duvall and magnitude versus time for a 75-day period.
• Cross-Sections and Relocations of mainshock and best-located aftershocks
• Complete catalog of analyzed aftershocks.

Notes

• Details about the earthquake magnitude
• Notes on felt reports, aftershocks and other earthquakes

MomentTensors from Broadband Seismograms

• Mainshock moment tensor solution by Oregon State
• Mainshock moment tensor solution by Univ of Washington
• Mainshock moment tensor solution by UC-Berkeley
• moment tensor solution for M 3.6 aftershock on May 4 (7:38am PDT)

Mainshock Acceleration Seismograms - explanation

• Green Mountain (Olympic Peninsula)
• Liberty Mine (Central Cascades)
• Longmire (Mt. Rainier)
• Additional Acceleration Seismograms from Terra Technology (manufacturer of seismic recording equipment in Redmond, WA).
• Special USGS report on Chasing Duvall aftershocks with portable Seismographs.

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Summary of the Public's Web Responses

By the end of May, 1996 we had received over 1,000 responses to a WEB based felt-report form of which 845 were determined to be legitimate, unique responses. A summary of these responses indicates we have recieved information mostly from people who felt this earthquake fairly strongly. Such information helps us to understand more about this earthquake as well as older, pre-instrumental events. A contour map shows the felt intensities estimated from these responses and averaged over zipcode areas.

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Other Sources of Information

• Earthquakes in the Pacific Northwest
• University of Washington Dept. of Earth and Space Sciences
• Cascade Region Earthquake Workgroup (CREW)

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Seismology Laboratory
Dept. of Earth and Space Sciences, Box 351310
University of Washington
Seattle, Washington 98195
Last updated Oct. 2, 1996

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University of Washington Dept. of Earth and Space Sciences, Box 351310 Seattle, WA, 98195-1310
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