Shallow structure of the Cascadia subduction zone beneath western Washington from spectral ambient noise correlation

2011 ◽  
Vol 116 (B7) ◽  
Author(s):  
Josh A. Calkins ◽  
Geoffrey A. Abers ◽  
Göran Ekström ◽  
Kenneth C. Creager ◽  
Stéphane Rondenay
Keyword(s):  
Subduction Zone ◽  
Ambient Noise ◽  
Cascadia Subduction Zone ◽  
Noise Correlation ◽  
Western Washington ◽  
Shallow Structure

Slope failures within and upstream of Lake Quinault, Washington, as uneven responses to Holocene earthquakes along the Cascadia subduction zone

2017 ◽  
Vol 89 (1) ◽  
pp. 178-200 ◽  
Author(s):  
Elana L. Leithold ◽  
Karl W. Wegmann ◽  
Delwayne R. Bohnenstiehl ◽  
Stephen G. Smith ◽  
Anders Noren ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Coastal Marsh ◽  
Seismic Survey ◽  
Cascadia Subduction Zone ◽  
Survey Analysis ◽  
Delta Front ◽  
Data Set ◽  
Reflection Seismic ◽  
Partial Channel ◽  
Western Washington

AbstractInvestigation of Lake Quinault in western Washington, including a reflection seismic survey, analysis of piston cores, and preliminary mapping in the steep, landslide-prone Quinault River catchment upstream of the lake, reveals evidence for three episodes of earthquake disturbance in the past 3000 yr. These earthquakes triggered failures on the lake’s underwater slopes and delta front, as well as subaerial landsliding, partial channel blockage, and forced fluvial sediment aggradation. The ages of the three Lake Quinault disturbance events overlap with those of coseismically subsided, coastal marsh soils nearby in southwest Washington that are interpreted to record ruptures of the Cascadia megathrust. Absent from Lake Quinault, however, are signals of obvious disturbance from five additional subduction earthquakes inferred to have occurred during the period of record. The lack of evidence for these events may reflect the limitations of the data set derived from the detrital, river-dominated lake stratigraphy but may also have bearing on debates about segmentation and the distribution of slip along the Cascadia subduction zone during prior earthquakes.

Performance of Lightly Confined Reinforced Concrete Columns in Long-Duration Subduction Zone Earthquakes

2005 ◽  
Vol 1928 (1) ◽  
pp. 184-192
Author(s):  
Seth E. Stapleton ◽  
Cole C. McDaniel ◽  
William F. Cofer ◽  
David I. McLean
Keyword(s):  
Reinforced Concrete ◽  
Subduction Zone ◽  
Concrete Columns ◽  
Cascadia Subduction Zone ◽  
Longitudinal Reinforcement ◽  
Reinforced Concrete Columns ◽  
Lap Splice ◽  
Western Washington ◽  
Subduction Zone Earthquake ◽  
Subduction Zone Earthquakes

The main goals of this research were to evaluate typical 1950s and 1960s as-built bridge columns in western Washington State in large subduction zone earthquakes and to investigate the dependency of failure mechanisms on loading history. Eight displacement histories were applied to eight nominally identical, half-scale, circular reinforced concrete columns expected to respond primarily in flexure (flexure-dominated). The main design deficiencies were a short longitudinal reinforcement lap splice at the base of the column (35 db) and inadequate transverse reinforcement. Test results showed that the failure mode of reinforced concrete columns was controlled by the column loading history. Three distinct failure mechanisms were observed for columns with an aspect ratio of approximately 4.2, assuming symmetric, double-curvature behavior. Large initial displacements greater than six times the effective yield displacement (Δ y) were likely to result in shear failures. Columns experiencing many displacements less than 4Δ y were likely to fail because of longitudinal reinforcement buckling. Columns subjected to several displacement excursions less than 4Δ y followed by an excursion greater than 6Δ y were likely to fail by longitudinal reinforcement slipping within the splice region. Despite the deficiencies present in circular reinforced concrete bridge columns built before 1975 in western Washington State, this study showed that flexure-dominated columns with a 35 db lap splice in multiple-column bent, three-or four-span bridges were not likely to experience significant damage in the predicted Cascadia Subduction Zone earthquake. However, other components of the bridge need to be assessed to determine whether the global bridge response is acceptable under the predicted Cascadia Subduction Zone earthquake.

Source Investigation and Comparison of the 1939, 1946, 1949 and 1965 Earthquakes, Cascadia Subduction Zone, Western Washington

2007 ◽  
Vol 164 (10) ◽  
pp. 1905-1919 ◽  
Author(s):  
Katy R. Wiest ◽  
Diane I. Doser ◽  
Aaron A. Velasco ◽  
James Zollweg
Keyword(s):  
Subduction Zone ◽  
Cascadia Subduction Zone ◽  
Western Washington

ASSESSING THE UTILITY OF δ13C AND BULK GEOCHEMISTRY IN ESTUARIES ALONG THE CASCADIA SUBDUCTION ZONE FOR COASTAL PALEOSEISMOLOGY

2017 ◽  
Author(s):  
Robert J. O'Donnell ◽  
◽  
Andrea D. Hawkes ◽  
Chad S. Lane ◽  
Simon E. Engelhart ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Cascadia Subduction Zone

scholarly journals A maximum rupture model for the central and southern Cascadia subduction zone—reassessing ages for coastal evidence of megathrust earthquakes and tsunamis

2021 ◽  
Vol 261 ◽  
pp. 106922
Author(s):  
Alan R. Nelson ◽  
Christopher B. DuRoss ◽  
Robert C. Witter ◽  
Harvey M. Kelsey ◽  
Simon E. Engelhart ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Cascadia Subduction Zone ◽  
Megathrust Earthquakes ◽  
Rupture Model

Electrical structure of the central Cascadia subduction zone: The EMSLAB Lincoln Line revisited

2014 ◽  
Vol 402 ◽  
pp. 265-274 ◽  
Author(s):  
Rob L. Evans ◽  
Philip E. Wannamaker ◽  
R. Shane McGary ◽  
Jimmy Elsenbeck
Keyword(s):  
Subduction Zone ◽  
Cascadia Subduction Zone ◽  
Electrical Structure

Simulation of Tsunamis from Great Earthquakes on the Cascadia Subduction Zone

Science ◽  
1990 ◽  
Vol 250 (4985) ◽  
pp. 1248-1251 ◽  
Author(s):  
M. K.-F. Ng ◽  
P. H. Leblond ◽  
T. S. Murty
Keyword(s):  
Subduction Zone ◽  
Cascadia Subduction Zone ◽  
Great Earthquakes
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