Abstract
Microearthquake data recorded on four ocean bottom seismometers are used to study shear‐wave splitting on the Endeavour Segment of the Juan de Fuca Ridge. The covariance matrix decomposition method is used to determine the sensor orientation from explosive shot data and to estimate the anisotropy parameters for 238 earthquake records. At three of the four sites, the results show a remarkably consistent fast direction parallel to the ridge axis. The time delays between the fast and the slow waves range from 40 to 200 ms, with an average of 90 ms. They are not clearly related to earthquake range, focal depth or source‐receiver azimuth. The splitting of the shear waves is interpreted as an effect of structural anisotropy due to the presence of ridge‐parallel cracks in the shallow crust. If we assume that anisotropy is concentrated in the upper 1–2 km, the splitting times require a high crack density of ∼0.1.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
