SEATTLE, Sept. 28 (UPI) -- Seismologists say Seattle sits in a deep, complex sedimentary basin known to amplify earthquake shaking, and have made a seismic assessment of the area.
Existing models can predict ground motions on rock sites but not in the more complex crustal and sedimentary basins found in the Seattle area, a release from the Seismological Society of America said Wednesday.
Measurements by University of Washington seismologists show a pronounced low velocity zone just north of the Seattle Fault in the vicinity of Elliott Bay, as well as more subtle variations in other parts of the city suggesting diverse underground geological features.
The knowledge of the internal structure of the sedimentary basin beneath Seattle, particularly the top 2.1 miles, will improve predictions of amplified ground motion, they said.
