Upper mantle anisotropy beneath Japan from shear wave splitting

Details Upper mantle anisotropy beneath Japan from shear wave splitting Upper mantle anisotropy beneath Japan from shear wave splitting

Aug 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005pepi..151..206l&link_type=abstract

Physics of the Earth and Planetary Interiors, Volume 151, Issue 3-4, p. 206-222.

Physics

31

Scientific paper

In this study, we utilize data from 64 broadband seismic stations of the Japanese F-net network to investigate the three-dimensional pattern of anisotropy in the subduction system beneath Japan. We have compiled a database of approximately 1900 high-quality splitting measurements, selected by visual inspection of over 25,000 records of S, SKS, and SKKS phases at F-net stations, covering a wide range of incidence angles, incoming polarization angles, and backazimuths. Analysis of the variations of measured splitting parameters with these parameters allows us to consider complexities in structure such as multiple anisotropic layers, dipping symmetry axes, and small-scale lateral variations in anisotropic properties. Here we focus on the presentation of the splitting measurements themselves; a detailed interpretation in terms of tectonics and mantle flow is beyond the scope of this paper. In the southern part of the F-net array, along the Ryukyu arc, we find that fast directions are consistently trench-parallel, with splitting times of 1 s or more. Moving northward along the array, the measured splitting patterns become more complicated, with significant variations in apparent splitting parameters that indicate complex anisotropic structure. Additionally, measured fast directions vary significantly over short length scales, and stations separated by less than 100 km often exhibit very different splitting behavior. This increase in complexity of anisotropic structure coincides geographically with the complicated slab morphology of the subducting Pacific plate. At stations on Hokkaido, to the north, and Kyushu, to the south, we see some evidence that the fast direction of anisotropy may rotate from trench-parallel close to the trench to subduction-parallel further away from the trench, which may correspond either to a change in stress conditions and/or volatile content, or to a change in flow regime.

Affiliated with

Also associated with

No associations

Rating

Upper mantle anisotropy beneath Japan from shear wave splitting does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Upper mantle anisotropy beneath Japan from shear wave splitting, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Upper mantle anisotropy beneath Japan from shear wave splitting will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-798160