Robinson Point Earthquake, Jan 28 07:11pm PST

Provided by: Seismology Lab
Dept. of Earth and Space Sciences, AK-50
University of Washington
Seattle, Washington 98195

UNIVERSAL DATE/TIME: 95/01/29 03:11:23
LOCAL DATE/TIME: 95/01/28 07:11:23 PM PST
DEPTH: 11 miles ( 16 km)
MAGNITUDE: 5.0
QUALITY: BB (A: high quality, D: poor quality)
LOCATION: 47.39 N latitude, 122.36 W longitude
10.9 miles ( 17.6 km) NNE of Tacoma
14.8 miles ( 23.8 km) S of Seattle

Felt in western Washington from Bellingham to Portland and east to Yakama.

• Map and X-section of earthquake activity in the mainshock area
• First motion Focal mechanism
• Moment tensor solution by Oregon State from Broad-band data
• Sample broad-band seismograms
• Map of strong-motion recorder sites, some of which recorded the Robinson Pt. earthquake and peak acceleration is given. Two sites are for instruments being tested by Terra Technology who kindly provided us with their data.
• Accelerograms from two Terra Technology IDS-3602A accelerographs (stations ZTER and ZMAG on map).
• Acceleration records generated from four broad-band seismograph stations located at Tolt Resevior (TTW), Longmire (LON), Satsop (SSW), and Liberty (LTY) are available in GIF format (21KB), or in PostScript format (168KB). The labels on this figure give the station name, component (horizontals rotated into radial and transverse), distance, azimuth, and maximum peak acceleration in m/s/s. We are planning to provide a map soon showing the position of peak ground acceleration at the sites for which these data are availablbe.
• Special Preliminary report by Shawn Dewberry.
• Special Felt Report via WEB study.
• Map of selected historic felt earthquakes in western Washington
• Major faults in the Puget Sound Region
• Sketch of possible interpretations of the fault responsible for the earthquake