Tectonic geomorphology of Bozdoğan and Karacasu grabens, western Anatolia


  • Erman Özsayın Hacettepe University https://orcid.org/0000-0003-3948-5482
  • Kadir Dirik Prof. Dr.
  • Faruk Ocakoğlu Prof. Dr.
  • Sanem Açıkalın Cartigny
  • Azad Sağlam Selçuk Assoc. Prof. Dr.




Karacasu graben, Bozdoğan graben, Geomorphic indices, Uplift rate, Seismic activity, Western Anatolia


Western Anatolia is one of the most rapidly extending and seismically active regions in the world. The circa N-S extension since the Early Miocene caused the formation of E-W trending major grabens and intervening horsts, having earthquake potentials with magnitude ≥5. The E-W oriented Büyük Menderes graben cross-cuts the broadly N-S oriented Bozdoğan and Karacasu grabens, of which the boundary faults of the latter are the source of seismic activity. Geomorphic indices, including drainage basin asymmetry, mountain front sinuosity, valley-floor width to valley height ratio, stream length-gradient index and normalized channel steepness index, were used to evaluate the boundary fault segments of the Bozdoğan and Karacasu grabens. The results indicate that both grabens are tectonically active and therefore regions of earthquake potential, consistent with the epicenters of earthquakes. Thus, it can be inferred that fault segments of second-order grabens, which are crosscut by the boundary faults of seismically active main depressions, are apparently reactivated by ongoing tectonism and may represent seismic activity. This suggestion applies also for similar basins located in the western Anatolia.

Author Biographies

Kadir Dirik, Prof. Dr.

Hacettepe University, Dept. of Geological Engineering, 06800, Ankara-Turkey

Faruk Ocakoğlu, Prof. Dr.

Eskişehir Osmangazi University, Dept. of Geological Engineering, 26040, Eskişehir-Turkey

Sanem Açıkalın Cartigny

New Castle University, School of Natural and Env. Sci., Newcastle upon Tyne NE1 7RU - UK

Azad Sağlam Selçuk, Assoc. Prof. Dr.

Van Yüzüncü Yıl University, Dept. of Geological Engineering, 65080, Van-Turkey