Seismic anisotropy of northeastern Algeria from shear-wave splitting analysis
- Author(s)
- Zohir Radi, Abdelkrim Yelles-Chaouche, Götz Bokelmann
- Abstract
There are few studies of internal deformation under northern Africa; here we present such a study. We analyze teleseismic shear-wave splitting for northeast Algeria, to improve our knowledge of lithospheric and asthenospheric deformation mechanisms in this region. We study waveform data generated by tens of teleseismic events recorded at five recently installed broadband (BB) stations in Algeria. These stations cover an area 2° across, extending from the Tellian geological units in the North to the Saharan Atlas units in the South. Analysis of SKS-wave splitting results insignificant spatial variations in fast polarization orientation, over a scale length of at most 100. km. The seismic anisotropy shows three clear spatial patterns. A general ENE-WSW orientation is observed under the stations in the north. This polarization orientation follows the direction of the Tell Atlas mountain chain, which is perpendicular to the convergence direction between Africa and Eurasia. Delay times vary significantly across the region, between 0.6 and 2.0. s. At several stations there is an indication of a WNW-ESE polarization orientation, which is apparently related to a later geodynamic evolutionary phase in this region. A third pattern of seismic anisotropy emerges in the South, with an orientation of roughly N-S. We discuss these observations in light of geodynamic models and present-day geodetic motion.
- Organisation(s)
- Department of Meteorology and Geophysics
- External organisation(s)
- Centre de Recherche en Astronomie Astrophysique et Géophysique
- Journal
- Physics of the Earth and Planetary Interiors
- Volume
- 248
- Pages
- 73-82
- No. of pages
- 10
- ISSN
- 0031-9201
- DOI
- https://doi.org/10.1016/j.pepi.2015.08.002
- Publication date
- 11-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105106 Geodynamics, 105122 Seismic, 105102 General geophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Geophysics, Space and Planetary Science, Physics and Astronomy (miscellaneous)
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/seismic-anisotropy-of-northeastern-algeria-from-shearwave-splitting-analysis(c2414a07-fc12-4096-8e35-e947e7ca2b1c).html