The North Anatolian Fault Zone (NAFZ) in Turkey is a major continental strike-slip fault, 1200 km long and with a current slip rate of 25 mm/yr. Historical records show that the NAFZ is capable of producing high-magnitude earthquakes, activating different segments of the fault in a westward progression. Currently, the NAFZ poses a major seismic hazard for the city of Istanbul, which is situated close to one of the two strands into which the fault splays in northwestern Turkey. Understanding of fault zone structure and properties at depth is essential to constrain where deformation occurs within the lithosphere and how strain localises with depth. In fact, geodynamic models explaining surface deformation require knowledge of the width and depth extent of the fault zone in both the crust and upper mantle. In this framework, this thesis aims to provide better constraints on fault zone geometry within the lithosphere. To achieve this objective P and S wave teleseismic tomography have been applied to the data recorded by a dense array of broadband seismic stations (DANA, Dense Array for Northern Anatolia); through teleseismic tomography it was possible to image the NAFZ structure in both the crust and uppermost mantle. In addition, joint inversion i of P-wave teleseismic data and local earthquake data collected using the same array provided a greatly improved resolution within the upper 20 km of the crust. Results from this work highlighted the presence of a shear zone associated to the northern branch of the NAFZ in the study area. The fault zone appears to be 15 km wide within the upper crust and narrows to < 10 km within the lower crust and to Moho depth. In the uppermost mantle its width is constrained to be 30 to 50 km.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:767325 |
| Date | January 2018 |
| Creators | Papaleo, Elvira |
| Contributors | Cornwell, David G. ; Rawlinson, Nicholas |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=239855 |
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