Keywords and Phrases
Anisotropy; Mantle Dynamics; Mantle Flow; Shear wave splitting
"Various tectonic features and the recent availability of high-quality broadband seismic data from the USArray and other seismic stations in the central and western United States (CWUS) provide a distinct opportunity to test different anisotropy-forming mechanisms. For the first part of the study, a total of 4138 pairs of well-defined shear wave splitting (SWS) parameters observed at 445 stations on the northern Great Plains show systematic spatial variations of anisotropic characteristics. Azimuthally invariant fast orientations subparallel to the absolute plate motion (APM) direction are observed at most of the stations on the Superior Craton and the southern Yavapai province, indicating that a single layer of anisotropy with a horizontal axis of symmetry is sufficient to explain the anisotropic structure. Based on the splitting measurements and previous results from seismic tomography and geodynamic modeling, we propose a model involving deflecting of asthenosphere flow by the bottom of the lithosphere and channeling flow by a zone of thinned lithosphere approximately along the northern boundary of the Yavapai province.
The second part of the study created an up-to-date SWS database for CWUS in the area of 125⁰ W to 90⁰ W, 26⁰ N to 52⁰ N to upgrade a previous database [Liu et al., 2014]. A total of 7452 pairs of high-quality measurements recorded by 1202 digital broadband seismic stations (both permanent and portable seismic networks) over the period of 1989-2014 is obtained. The current version includes 23448 pairs of well-defined splitting parameters in three phases, i.e. PKS, SKKS and SKS.
The dissertation is a combination of two journal papers published in 2014 and 2016, respectively"--Abstract, page iv.
Liu, Kelly H.
Gao, Stephen S.
Flori, Ralph E.
Rogers, J. David
Gertsch, Leslie S.
Geosciences and Geological and Petroleum Engineering
Ph. D. in Geology and Geophysics
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Seismic anisotropy and mantle flow beneath the Northern Great Plains of North America
- A uniform database of teleseismic shear wave splitting measurements for the western and central United States: December 2014 update
xii, 137 pages
© 2016 Bin Yang, All rights reserved.
Dissertation - Open Access
Library of Congress Subject Headings
Shear waves -- Measurement
Electronic OCLC #
Yang, Bin, "Seismic anisotropy and mantle dynamics beneath the central and western United States" (2016). Doctoral Dissertations. 2521.