Investigation of twelve earthquakes off the Oregon and northern California coasts

• Main Author: Rinehart, Verill Joanne
• Other Authors: Dehlinger, Peter
• Language: en_US
• Published: 2012
• Subjects: Earthquakes; Faults (Geology)
• Online Access: http://hdl.handle.net/1957/30255

Twelve earthquakes off the Oregon and Northern California coasts were used in this research to study whether faulting associated with these quakes was of the San Andreas type as observed in California. The first motions of the incident P and S waves recorded at various seismic stations in the Pacific Northwest were used to obtain a fault plane solution for these earthquakes. Nine earthquakes exhibited faulting which could be consistent with San Andreas type of motion, where one of these motions was based on first P and S data, six others were consistent with either northwesterly right-lateral or northeasterly left-lateral motions, and two were recorded at so few stations that faulting could not be defined through a fault plane solution. One earthquake was located in the region of the Gorda Escarpment west of Cape Mendocino, California, and displacements appear to be associated with that zone, one earthquake had Garlock-type displacements as defined through P and S motions, and one earthquake was not associated with any of the above types of faults. === Graduation date: 1964