South-Central Section - 45th Annual Meeting (2729 March 2011)
Paper No. 16-3
Presentation Time: 8:00 AM-12:00 PM


ELSHEIKH, Ahmed, Geological Sciences and Engineering, Missouri University of Science and Technology, 1400 N. Bishop Avenue, 129 McNutt Hall, Rolla, MO 65409, and GAO, Stephen, Geological Sciences and Engineering, Missouri University for Science and Technology, 129 McNutt Hall, 1400 North Bishop Avenue, Rolla, MO 65409

Splitting of P-to-S converted phases (XKS, including PKS, SKKS, and SKS) at the core-mantle boundary on the receiver side is one of the most effective tools to measure the direction and strength of fabrics in the mantle. This work presents new XKS splitting measurements obtained from broadband seismic stations in the vicinity of Hawaii. Limited quality and quantity of previous XKS studies in Hawaii resulted in contradicting conclusions regarding the characteristics of mantle fabrics and the causes that are responsible for generating the observed seismic anisotropy. This study adapted a robust procedure for measuring and objectively ranking XKS splitting parameters, which include the splitting time and the polarization direction of the fast wave. Manual visualization check was applied to the results of the automatic calculations to ensure that no high quality events were neglected and no low quality results were included. The resulting splitting parameters show systematic variation with the arriving azimuth of the XKS rays, suggesting a two-layer model. The lower layer is consistent with the current absolute plate motion (AMP) direction, implying that mantle flow in the asthenosphere is responsible for generating the observed anisotropy. The fast direction in the upper layer is close to the direction of major fracture zones, suggesting a lithospheric origin.

South-Central Section - 45th Annual Meeting (2729 March 2011)
General Information for this Meeting
Session No. 16--Booth# 3
General Geology (Posters)
Chateau Bourbon: Pre-Function Area
8:00 AM-12:00 PM, Tuesday, 29 March 2011

Geological Society of America Abstracts with Programs, Vol. 43, No. 3, p. 42

© Copyright 2011 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.