..., probably due to near-lithostatic fluid pressure on the décollement horizon. Recent multichannel seismic and sidescan sonar studies have demonstrated the existence of an oblique, basement-involved, left-lateral strike-slip fault, termed the Wecoma fault. It cuts abyssal plain sediments and oceanic basement...

... by the opposite block of a strike-slip fault, which is same as the relative slip direction of the opposite block. (B) Composite block diagram of intersection between the Wecoma fault and deformation front (after Goldfinger et al., 1992 ). (C) Interpretation of two seismic profiles adjacent to the Daisy Bank...

..., not restricted to tearing only the inclined portion of down-going lithosphere, but often traverses across the trench within the proximal ‘intra-plate’ oceanic domain. The Wecoma fault, a left-lateral strike slip active fault traverses the floor of the Cascadia basin, seaward of the Oregon convergent margin...

... and ocean tides were recorded on tiltmeters installed within the seismometer packages. Microearthquakes show a strong correlation with tidal lows, suggesting that faulting is occurring preferentially when ocean loading is at a minimum. The harmonic tremor, interpreted as the movement of superheated fluid...

.... For a few high slip‐rate (>5 mm/yr) faults off the coast of the Pacific (Alvin Canyon, Daisy Bank, and Wecoma), model slip rates are consistently lower than their geologic rates, especially for Wecoma. Because we do not have any seafloor GPS observations to constrain their motions, model slip rates...

... a strong lateral velocity contrast in the lower crust. This velocity contrast is beneath the surface trace of the San Andreas fault and tracks along the fault to the triple junction and then along the Mendocino fracture zone. Velocity values appropriate for mafic rocks are more than 5 km shallower...

... the development of productive seep environments. Although strike-slip faults have been previously considered to be effective dewatering conduits in other accretionary settings (e.g., Wecoma fault, Oregon; Tobin et al., 1993 ), the lack of observed focused seepage along such faults on the southern margin supports...

.... Mitchell, D. Wiens, the R/V Wecoma crew, M. Cunningham, and the Emergency Management Office in Saipan, Commonwealth of the Northern Mariana Islands. The Ocean Drilling Program (ODP) provided sediment and serpentinite samples. ODP is sponsored by the National Science Foundation (NSF) and participating...

..., suggest that the seismicity occurred at plate boundary depths, possibly on the Cascadia megathrust. This concentrated activity in the seismogenic zone may represent patches on the fault plane with anomalous frictional characteristics, possibly caused by subducted topographic features, which can affect...

... depths. The morphology of the shelf is dominated by tectonics associated with the northward-migrating Mendocino triple junction, modified by sediment accumulations sourced by the coastal rivers ( Burger et al., 2003 ). North-south compression has formed uplifting anticlines and faults that trend north...