Morphometric and Kinematic Analysis of Gumuldur Fault and Its Seismotectonic Implications for Western Anatolia

Yerli B., SOFTA M., SÖZBİLİR H.

TURKIYE JEOLOJI BULTENI-GEOLOGICAL BULLETIN OF TURKEY, cilt.64, sa.3, ss.349-382, 2021 (ESCI) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 64 Sayı: 3
  • Basım Tarihi: 2021
  • Doi Numarası: 10.25288/tjb.846813
  • Dergi Adı: TURKIYE JEOLOJI BULTENI-GEOLOGICAL BULLETIN OF TURKEY
  • Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI)
  • Sayfa Sayıları: ss.349-382
  • Anahtar Kelimeler: Gumuldur Fault, kinematic analysis, morphometric analysis, Western Anatolia, RELATIVE TECTONIC ACTIVITY, BALIKESIR TRANSFER ZONE, BUYUK MENDERES GRABEN, ACTIVE TECTONICS, AEGEAN SEA, GEDIZ GRABEN, NEOTECTONIC EVOLUTION, SURROUNDING REGIONS, BASIN FORMATION, EMPIRICAL RELATIONSHIPS
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

Kusadasi Bay, which is controlled by active normal faults, is located in an evolving graben in the west of the Western Anatolian Extension System. Gumuldur Fault (GF), which restricts Kusadasi Bay to the north, has approximately 30 km long, fragmented structure between Urkmez and Ahmetbeyli. GF, which strikes N (50 degrees-55 degrees) W direction, forms a sharp morphological escarpment between Urkmez and Ahmetbeyli starting from Paleozoic basement rocks to Quaternary alluvium units. The dip angle of the fault planes increases to the west (40 degrees-85 degrees SW), and the fault is a dip-slip active normal fault with convex structure and geometry toward the northeast. To unravel the Quaternary activity of Gumuldur Fault and the evaluation of the regional uplift, morphometric and kinematic analysis was performed for the first time on the fault that includes well-preserved geomorphological markers. Quantitative measurement of morphometric indices such as mountain front sinuosity (S-mf: 1.13-1.56), valley floor width to height ratio (V-f : 0.10-1.00), percentage faceting L-f/L-s ([L: 4.75-88.35, S: 0.12-9.30]), asymmetry factor (AF: 19-78), basin shape geometry (B-s: 1.05-5.98), stream length gradient (Hack) index (SL: 25-6094.44), hypsometric curve and hypsometric integral (HI: 0.16-0.53) and rock strength and climate parameters indicate that the footwall of the GF has been uplifting toward the west with more than 0.5 mm per year. According to kinematic studies of the GF, which is geometrically composed of three parts, the region developed under the control of an extensional regime oriented NNE-SSW. If it is broken into seperate segments, it has the potential to produce earthquakes with a magnitude of 6.12, 6,45 and 5.78, respectively. If considered as a single segment, it has the potential to produce earthquakes with a magnitude of 6.81 in Kusadasi Bay. For this reason, trench-based paleoseismological studies are needed to reveal the past activity of Gumuldur Fault and to determine the seismic hazard level in the region.