A joint geophysical investigation of the Cascadia subduction system in central Washington using dense arrays of passive seismic and magnetotelluric station data
Abstract
The use of multiple geophysical methods to explore a given region provides better constraints and more robust interpretation than can be obtained using a single method. We explore the Cascadia subduction system using seismic and magnetotelluric data that has been collected along a profile running roughly east-west through west-central Washington State. We present images generated from the Generalized Radon Transform migration of teleseismic data collected from 41 three-component broadband stations from the CAFÉ (Cascadia Array for Earthscope) experiment, Earthscope Transportable Array, and the Pacific Northwest Seismic Network over a period of roughly 26 months. We also present results from the 2-D non-linear conjugate gradient inversion of magnetotelluric data recently acquired from 60 broadband and 21 long period stations along a collocated profile. Taken together, these results enable us to explore the constraints to slab geometry, volatile release, fluid transport, and melting within the subduction zone structure. We consider how each geophysical method informs us about the subsurface, and explore how the two sets of results can be used to constrain one another. Finally, we compare the results of these experiments to similar previous work conducted along profiles to the north and south, gaining insight into along-strike variations and their potential connections to the surface expressions of the subduction process.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.V54B..03M
- Keywords:
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- 0600 ELECTROMAGNETICS;
- 3060 MARINE GEOLOGY AND GEOPHYSICS / Subduction zone processes;
- 7240 SEISMOLOGY / Subduction zones