Frederiksen, AW, Thompson, DA, Rost, S et al. (8 more authors) (2015) Crustal thickness variations and isostatic disequilibrium across the North Anatolian Fault, western Turkey. Geophysical Research Letters, 42 (3). 751 - 757. ISSN 0094-8276
Abstract
We use teleseismic recordings from a dense array of seismometers straddling both strands of the North Anatolian Fault Zone to determine crustal thickness, P/S velocity ratio and sedimentary layer thickness. To do this, we implement a new grid search inversion scheme based on the use of transfer functions, removing the need for deconvolution for source normalization and therefore eliminating common problems associated with crustal-scale receiver function analysis. We achieve a good fit to the data except at several stations located in Quaternary sedimentary basins, where our two-layer crustal model is likely to be inaccurate. We find two zones of thick sedimentary material: one north of the northern fault branch, and one straddling the southern branch. The crustal thickness increases sharply north of the northern strand of the North Anatolian Fault Zone (NAFZ), where the fault nearly coincides with the trace of the Intra-Pontide Suture; the velocity ratio changes across the southern fault strand, indicating a change in basement composition. We interpret these changes to indicate that both strands of the NAFZ follow preexisting geological boundaries rather than being ideally aligned with the stress field. The thick crust north of the northern NAFZ strand is associated with low topography and so is inconsistent with simple models of isostatic equilibrium, requiring a contribution from mantle density variations, such as possible loading from underthrust Black Sea oceanic lithosphere.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | Turkey; North Anatolian Fault; Moho; Crustal thickness; Vp/vs |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Funding Information: | Funder Grant number NERC NE/I028017/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 10 Mar 2015 13:47 |
Last Modified: | 20 Oct 2015 10:04 |
Published Version: | http://dx.doi.org/10.1002/2014GL062401 |
Status: | Published |
Publisher: | Blackwell |
Refereed: | Yes |
Identification Number: | 10.1002/2014GL062401 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:84076 |