Abstract
The local subduction geometry at a site south of Puget Sound in western Washington is investigated using teleseismicP-waveforms recorded on a three-component event triggered seismograph. The data are processed using source equalization deconvolution in order to isolate locally convertedP-to-S arrivals and stacked to improve the signal-to-noise ratio. Stable arrivals in the radial component indicate an oceanic Moho within the subducted slab at a depth of about 53 km beneath the station. Observed amplitude variations with azimuth in the radial data, as well as qualitative aspects of the tangential data, are used to establish a slab dip of 16° to the southeast. Our results are compatible with previous results from a site 60 km to the west, and further confirm a substantial warp in the regional geometry of the subducted Juan de Fuca plate.
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Lapp, D.B., Owens, T.J. & Crosson, R.S. P-waveform analysis for local subduction geometry south of Puget Sound, Washington. PAGEOPH 133, 349–365 (1990). https://doi.org/10.1007/BF00877168
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DOI: https://doi.org/10.1007/BF00877168