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Shear wave splitting observations in the Chinese Tianshan orogenic belt
Author(s) -
Chen YunPing,
Wang LiangShu,
Mi Ning,
Li Hua,
Yu DaYong,
Xu MingJie,
Liu ShaoWen,
Li Cheng,
Xu Zhen
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl021686
Subject(s) - geology , seismology , subduction , mantle (geology) , shear (geology) , crust , shear wave splitting , broadband , geodesy , tectonics , geophysics , paleontology , telecommunications , computer science
A linear array of 26 3‐component broadband digital stations across the Chinese Tianshan Orogenic Belt (CTOB) was deployed for 13 months to measure the shear wave splitting. Fast direction of teleseismic shear waves beneath the southern CTOB is NWW‐SEE and gradually turns into NEE‐SWW in the north. Delay times are 0.65∼1.48s with average value of 0.97 ± 0.15s and the maximum delay time is observed in the middle mountain and decrease in the south and the north. Fast directions are generally parallel to the strike of the orogenic belt, indicating that more than one hundred kilometers of upper mantle is involved in collisional deformation. Compared to other stations, change in fast direction for stations in the south and north ends of the array is probably resulted from subduction of the Tarim block and the Junggar block into the Tianshan range, respectively.