DEFORMATION PATTERN AND STRUCTURAL ANALYSIS ALONG THE WESTERN TERMINATION OF THE NORTH ANATOLIAN FAULT

Postgraduate Thesis uoadl:2847356 438 Read counter

Unit:
Κατεύθυνση Τεκτονική
Library of the School of Science
Deposit date:
2019-01-29
Year:
2019
Author:
Trikalinou Georgia
Supervisors info:
Κράνης Χαράλαμπος, Επίκουρος Καθηγητής, τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Σακελλαρίου Δημήτρης,Διευθυντής ερευνητής, ΕΛΚΕΘΕ
Λέκκας Ευθύμης, Καθηγητής, τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Original Title:
DEFORMATION PATTERN AND STRUCTURAL ANALYSIS ALONG THE WESTERN TERMINATION OF THE NORTH ANATOLIAN FAULT
Languages:
Greek
Translated title:
DEFORMATION PATTERN AND STRUCTURAL ANALYSIS ALONG THE WESTERN TERMINATION OF THE NORTH ANATOLIAN FAULT
Summary:
The deformation pattern and the structural analysis along North Aegean Trough (NAT) is a research topic for many researchers over the last decades. In the present master thesis, the western termination of the NAT was examined, in order to analyze the tectonic structures that consist the North Anatolian Fault.
The database utilized in the present analysis, i.e. swath bathymetry data and seismic profiles, was acquired in the framework of the nationally funded "YPOTHER/Aegean Explorations" project, implemented by the Institute of Geology & Mining Exploration (IGME) and the Hellenic Centre for Marine Research (HCMR). Swath bathymetry data were acquired with a 20 kHz SeaBeam 2120 (L3 ELAC Nautic), hull-mounted, multibeam system and were complemented with data obtained by HCMR in 2000, reprocessed at 25m grid. The fault network across the western branch of NAF was analyzed using 53 seismic profiles, of which 38 are airgun 10 in3 seismic profiles and 15 are airgun 40 in3 seismic profiles.
Firstly, the submarine morphology map was created utilizing the swath bathymetry data. Using the aforementioned map, the morphological characterization of the study area was conducted, dividing it in 5 areas (Alonnisos Deep, Psathoura Ridge, Psathoura Deep, Myrina Ridge and Lemnos Deep) regarding their horizontal and vertical differentiation. Following, a slope map was constructed in order to verify the existence of active tectonic structures. Additionally, the preparation (filtering) and the analysis of the 53 seismic profiles was made, that is the identification of distinctive seismic layers, basement rocks and faults.
Regarding the conclusions of this research, the western termination of the NAF is a fault – controlled region. The NAF is not a linear strike – slip fault with vertical fault plane, but rather a fault zone with numerous parallel to subparallel faults, overlapping each other. The areas between the fault segments are presented either relatively uplifted or subsided, consisting 5 morphological areas with particular characteristics, 3 releasing bends (Alonissos, Psathoura and Lemnos Deeps) and 2 restraining bends (Psathoura and Myrina Ridge). The fault segments of the NAF zone are interpreted as the upper parts of positive and negative flower structures, they are almost vertical and accommodate dip – slip component which increases towards SW. In addition, the projection of fault segments on the slope map that was previously constructed, confirmed that these fault segments are active, since their location coincides with the areas that present abrupt change of slope. Lastly, the projection of determined focal mechanisms for all the earthquakes with magnitude Mw > 3.5 that occurred in the vicinity of the study area, from 2006 until present, verified the pure dextral strike – slip motion with a dip – slip component along the fault segments of the NAF zone.
Main subject category:
Science
Keywords:
North Anatolian Fault, North Aegean Trough, strike-slip, transtension, transpression
Index:
Yes
Number of index pages:
2
Contains images:
Yes
Number of references:
184
Number of pages:
108
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