Open AccessImaging the basin and fault geometry from the multichannel seismic reflection data in the Tekirdağ Basin, Marmara Sea, Turkey
Author(s) -
Kanbur Zakir,
Alptekin Ömer,
Utkucu Murat,
Kanbur Süveyla
Publication year - 2007
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2007.03356.x
Subject(s) - structural basin , geology , seismology , fault (geology) , north anatolian fault , pull apart basin , reflection (computer programming) , transform fault , basin and range topography , tectonics , geomorphology , sedimentary basin , computer science , programming language
SUMMARY Determination of the fault geometry in the Marmara Sea has been a major problem for the researchers after the occurrence of the 1999 August 17 Golcuk ( M = 7.4) earthquake. To shed a light to the problem we applied the pre‐stack Kirchhoff depth migration technique to the multichannel seismic reflection data of three profiles to investigate the basin and fault geometry in the Tekirdağ Basin in the western Marmara Sea. The boundary of the basin and its sediments were revealed in N–S and NE–SW directions in depth sections. We identify major fault types involving these structures at different locations in Tekirdag Basin showing that the basin is developed under their movement. The North Anatolian Fault is imaged and interpreted as transtensional character at the centre of the Tekirdağ Basin that is symmetrically divided with a large distributed zone. The fault plane is imaged through the depth of 2 km dipping to the north with 90° in the upper 350 m and 82° in the lower part. The basin thickness reaches about 2.5 km at that point. Syn‐transform sediments of the basin are disturbed by some normal faults dipping to the north. These faults are represented by notable displacements of the reflections which prompted us to consider them as a potential tsunami source if they move during a large earthquake along the major fault. Another major fault is identified at the westernmost of the basin. Because it shows the same character as Ganos fault, it might be submarine part of it. It has reverse component with the dip angle of 65° to the north and trending along the western flank of the basin. A reverse fault is identified appearing in low angle (∼20°) surrounding the edge of the submarine slide at southwest of the basin. From its geometry it is interpreted as a local fault formed between two main faults. From the sketch of the basin and the fault geometry obtained from the images we suggest that the basin should be formed by a pull‐apart system.