The delta front of the Duwamish River valley near Elliott Bay and Harbor Island is founded on young Holocene deposits shaped by sea-level rise, episodic volcanism, and seismicity. These river-mouth deposits are highly susceptible to seismic soil liquefaction and are potentially prone to submarine landsliding and disintegrative flow failure.
A highly developed commercial-industrial corridor, extending from the City of Kent to the Elliott Bay/Harbor Island marine terminal facilities, is founded on the young Holocene deposits of the Duwamish River valley. The deposits of this Holocene delta have been shaped not only by relative sea-level rise but also by episodic volcanism and seismicity. Ground-penetrating radar (GPR), cores, in situ testing, and outcrops are being used to examine the delta stratigraphy and to infer how these deposits will respond to future volcanic eruptions and earthquakes in the region. A geotechnical investigation of these river-mouth deposits indicates high initial liquefaction susceptibility during earthquakes, and possibly the potential for unlimited-strain disintegrative flow failure of the delta front.
|Publication Subtype||USGS Numbered Series|
|Title||Seismic stability of the Duwamish River Delta, Seattle, Washington|
|Series title||Professional Paper|
|Publisher||U.S. Geological Survey|
|Publisher location||Reston, VA|
|Contributing office(s)||Western Coastal and Marine Geology|
|Description||iii, 11 p.|
|Larger Work Type||Report|
|Larger Work Subtype||USGS Numbered Series|
|Larger Work Title||Earthquake Hazards of the Pacific Northwest Coastal and Marine Regions, USGS Professional Paper 1661|
|Other Geospatial||Duwamish River Delta|
|Google Analytic Metrics||Metrics page|