Wogan, Nicholas2016-10-252016-10-252016-06https://hdl.handle.net/1794/2039339 pages. A thesis presented to the Department of Physics and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2016.I have produced four 2-D magnetotelluric conductivity inversions of MOCHA data roughly between the latitudes of 43N and 46N that indicate fluid variation along strike in the Cascadia subduction zone. I directly compare these results to Wannamaker et al. 2014 EMSLAB inversion and find the models to be very similar despite the use of different data sets and inversion methods. Conductivity structure along the plate interface supports the hypothesis that there is "partial creeping" occurring in the locked zone in central Cascadia, as well as the possible presence of a secondary, inboard locked zone at 44.5N in the ETS region. The variability of conductivity along strike also suggests a more permeable crust in the northern region of Cascadia directly overhead the ETS zone, and more fluid accumulation in this same region. This study indicates that a more permeable overlying crust, combined with larger amounts of fluid present may be critical components of rapid ETS occurrence.en-USCreative Commons BY-NC-ND 4.0-USGeophysicsGeologyMagnetotelluricsCascadiaSubduction ZoneMegathrustEarthquakeThesis / Dissertation