Hydrate Ridge is an accretionary thrust ridge located on the lower slope of the central Cascadia convergent margin. Structural mapping based on two-dimensional and three-dimensional multichannel seismic reflection profiles and gridded bathymetry coupled with deep-towed sidescan sonar data and Ocean Drilling Program (ODP) biostratigraphy suggests that seafloor fluid venting patterns...
Bathymetry and magnetic anomalies indicate that a seamount on the Juan de Fuca plate has been subducted beneath the central Cascadia accretionary complex and is now located similar to 45 km landward of the deformation front. Passage of this seamount through the accretionary complex has resulted in a pattern of...
Increasing public awareness that the Cascadia subduction zone in the Pacific Northwest is capable of great earthquakes (magnitude 9 and greater) motivates the Cascadia Initiative, an ambitious onshore/offshore seismic and geodetic experiment that takes advantage of an amphibious array to study questions ranging from megathrust earthquakes, to volcanic arc structure,...
From December 2006 to November 2011, the Pacific Northwest Seismic Network (PNSN)
reported 467 earthquakes in a swarm 60 km east of Mt Hood near the town of Maupin, Oregon.
The swarm included 20 M[subscript D] ≥ 3.0 events, which account for over 80 per cent of the cumulative
seismic...
The Queen Charlotte Fault (QCF) is a major strike-slip fault that forms the boundary between the Pacific and North American plates from 51° to 58° N. Near 53.2° N, the angle of oblique convergence predicted by the Mid-Ocean Ridge VELocity (MORVEL) interplate pole of rotation decreases from >15° in the...
The Queen Charlotte fault (QCF) is a dextral transform system located offshore of southeastern Alaska and western Canada, accommodating ∼4.4 cm/yr of relative motion between the Pacific and North American plates. Oblique convergence along the fault increases southward, and how this convergence is accommodated is still debated. Using seismic reflection...
Several approaches to interpreting the Cascadia paleoseismic record are used to derive relationships between fault area, slip, and moment and to compare the results with the scaling relationships determined by Somerville et al. (2015) for recent subduction-zone events. In two models (CA12a and CA12b), taken from Goldfinger et al. (2012),...
Several approaches to interpreting the Cascadia paleoseismic record are
used to derive relationships between fault area, slip, and moment and to compare the
results with the scaling relationships determined by Somerville et al. (2015) for recent
subduction-zone events. In two models (CA12a and CA12b), taken from Goldfinger
et al. (2012),...
Several approaches to interpreting the Cascadia paleoseismic record are
used to derive relationships between fault area, slip, and moment and to compare the
results with the scaling relationships determined by Somerville et al. (2015) for recent
subduction-zone events. In two models (CA12a and CA12b), taken from Goldfinger
et al. (2012),...