Cover Image

Double layer anisotropy beneath the New Madrid seismic zone and adjacent areas: insights from teleseismic shear wave splitting

Moikwathai Dax Moidaki
  • Moikwathai Dax Moidaki
    Physics Department, University of Botswana, Gaborone, Botswana | moidaki@mopipi.ub.bw

Abstract

A total of 93 well-defined PKS, 54 SKKS, and 126 SKS shear-wave splitting parameters are determined at 25 broadband seismic stations in an approximately 1000 by 1000 km2 area centered at the New Madrid seismic zone (NMSZ) in order to test the existence of two anisotropic layers and to map the direction and strength of mantle fabrics. The individual splitting parameters suggest a significant and systematic spatial and azimuthal variation in the splitting parameters. The azimuthal variations at most stations can be explained as the results of present SW ward asthenospheric flow and NNE trending lithospheric fabrics formed during past orogenic events. In the NMSZ, rift-parallel fast directions (potentially related to a long-rift flow) and rift-orthogonal fast directions from small-scale mantle convection are not observed. In addition, reduction in splitting times as a result of vertical asthenospheric flow is not observed.

Keywords

shear wave splitting, New Madrid Seismic Zone, anisotropy, splitting time.

Full Text:

PDF
Submitted: 2013-08-07 15:55:35
Published: 2014-02-28 16:41:35
Search for citations in Google Scholar
Related articles: Google Scholar
Abstract views:
1129

Views:
PDF
222

Article Metrics

Metrics Loading ...

Metrics powered by PLOS ALM


Copyright (c) 2014 Moikwathai Dax Moidaki

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
 
© PAGEPress 2008-2018     -     PAGEPress is a registered trademark property of PAGEPress srl, Italy.     -     VAT: IT02125780185     •     Privacy