Doctoral Dissertations
Keywords and Phrases
Crustal structure; Crustal thickness; Receiver functions; Vp/Vs
Abstract
"This study investigates crustal characteristics beneath the western United States. Crustal parameters, including crustal thickness (H), mean Vp/Vs, and the sharpness of the Moho as quantified by the amplitude of the P-to-S converted phases from the Moho, are measured at a total of 1000 permanent and portable broadband seismic stations using over 150,000 receiver functions recorded between 1988 and 2012. The study area is composed of a diverse set of tectonic provinces formed by a series of tectonic events, and is thus ideal for investigating crustal formation and modification by different tectonic processes. The resulting crustal thickness varies from 21 km in the Pacific Border to 57 km beneath the Rocky Mountains, with a mean thickness of 38.5±1.8 km. The Vp/Vs varies from 1.70 in the Great Plains to 1.90 in the Columbia River Basalt Group (north Columbia Plateau), with a mean value of 1.77±0.014. We explore relationship between crustal thickness, Vp/Vs, surface elevation, and the age of the crust, and find no positive relationship between crustal thickness and Vp/Vs. In addition, no clear connections between the Vp/Vs and the crustal age are found. High Vp/Vs and relatively low R values are observed at locations with crustal partial melts inferred by seismic tomography, such as Yellowstone, the eastern Snake River Plain, and the southeastern portion of the Rio Grande Rift. Moreover, secondary arrivals that arrive before the P-to-S conversion from the Moho and probably reflect the top of the so-called 7.xx layer, are observed beneath the Cheyenne Belt, boundary of Snake River Plain and Basin Range, as well as beneath the Wyoming craton, Colorado Plateau, and Delaware Basin"--Abstract, page iii.
Advisor(s)
Gao, Stephen S.
Liu, Kelly H.
Committee Member(s)
Eckert, Andreas
Mickus, Kevin
Yang, Wan
Department(s)
Geosciences and Geological and Petroleum Engineering
Degree Name
Ph. D. in Geology and Geophysics
Publisher
Missouri University of Science and Technology
Publication Date
Fall 2014
Pagination
ix, 103 pages
Note about bibliography
Includes bibliographical references (pages 86-102).
Geographic Coverage
West (U.S.)
Rights
© 2014 Uranbaigal Purevsuren, All rights reserved.
Document Type
Dissertation - Open Access
File Type
text
Language
English
Subject Headings
Geology, Structural -- West (U.S.)
Poisson's equation
Seismic waves -- Mathematical models
Thesis Number
T 10620
Electronic OCLC #
902735885
Recommended Citation
Purevsuren, Uranbaigal, "Crustal thickness and Vp/Vs beneath the Western United States: Constraints from stacking of receiver functions" (2014). Doctoral Dissertations. 2354.
https://scholarsmine.mst.edu/doctoral_dissertations/2354