Displacements and Kinematics of the February 1, 1944 Gerede Earthquake (North Anatolian Fault System, Turkey): Geodetic and Geological Constraints

Ayhan, Mehmet Emin
Kocyigit, Ali
The North Anatolian Fault System (NAFS) is an approximately 2-110-km-wide, 1600-km-long right-lateral intra-continental transform fault boundary between the Anatolian platelet and the Eurasian plate. The Gerede fault zone is one of the major active structures in the western section of the NAFS. It is a 1-9-km-wide, 325-km-long and ENE-trending dextral strike-slip fault zone, with a total accumulated offset since its initiation (Late Pliocene) of about 43 km. This offset indicates an average geological slip rate of 16.5 mm/yr. The 1 February 1944 Gerede earthquake occurred within the Gerede fault zone. Based on recent field geological mapping of the rupture traces and offsets on it, the average and peak lateral offsets were measured to be 4.37 m and 7.16 m, respectively. A triangulation network covering the region was first set up between 1936 and 1943. Twentyeigth existing points of the network were reoccupied by GPS receivers between 1995 and 2004. Coseismic displacements for the February 1, 1944 Gerede earthquake were obtained at the reoccupation points by removing interseismic deformation and coseismic displacements of recent earthquakes. Modelling the coseismic displacements in elastic half space resulted in a rupture surface slippage of 4.40 +/- 0.11 m and 1.02 +/- 0.17 m in dextral and normal dip-slip directions, respectively. The 191-km-long and 16-km-deep rupture surface strikes N76 degrees E and dips at 85 degrees +/- 5 degrees both to north and south. In the present study the estimated geodetic scalar moment and moment magnitudes are M(o) = 4.02 x 10(20) Nm and M(w) = 7.74, respectively. The rupture surface was extended down dip to a depth of about 28 km, and a significant slip distribution was recovered. Based on both the geodetic and geological data, the recurrence intervals for great seismic events to be sourced from the Gerede fault zone were calculated as 232 +/- 25 years and 266 +/- 35 years, respectively.


Lake Hazar basin: A negative flower structure on the east anatolian fault system (EAFS), SE Turkey
Aksoy, Ercan; Inceoez, Murat; Kocyigit, Ali (2007-01-01)
The East Anatolian Fault System ( EAFS) is a 30-km-wide, 700-km-long and NE-trending sinistral strike-slip megashear belt between the Anatolian platelet in the northwest and African-Arabian plates in the southeast. It is located between Karliova County in the NE and Karatas ( Adana)-Samandag ( Antakya) in the SW. In the Lake Hazar region, the EAFS consists of five fault zones. These are, from north to south, the Elazig fault zone, the Uluova fault zone, the Sivrice fault zone, the Adiyaman fault zone and th...
Earthquake focal mechanism and stress tensor analysis along the central segment of the North Anatolian fault
Karasözen, Ezgi; Özacar, Atilla Arda; Kaymakcı, Nuretdin; Department of Geological Engineering (2010)
The North Anatolian Fault (NAF) is one of the world’s largest active continental strikeslip faults, and forms the northern margin of the Anatolian plate. Although its geologic and geomorphologic features are well defined, crustal deformation and associated seismicity around central segment of the NAF is relatively less-known. In this study, we analyzed locations and focal mechanisms of 172 events with magnitude ≥ 3, which are recorded by 39 broadband seismic stations deployed by the North Anatolian Passive ...
Shear wave splitting along a nascent plate boundary: the North Anatolian Fault Zone
Biryol, C. Berk; Zandt, George; Beck, Susan L.; Özacar, Atilla Arda; Adiyaman, Hande E.; Gans, Christine R. (Oxford University Press (OUP), 2010-06-01)
P>The North Anatolian Fault Zone (NAFZ) is a transform structure that constitutes the boundary between the Anatolian Plate to the south and the Eurasia Plate to the north. We analysed the properties of the upper-mantle strain field and mantle anisotropy in the vicinity of NAFZ via splitting of SKS and SKKS phases. We used data from the North Anatolian Fault (NAF) passive seismic experiment. This is the first study that analyses the upper-mantle anisotropy in this region and our results indicate that the obs...
Neotectonics of the southeast Marmara region, NW Anatolia, Turkey
Gürer, Ömer Feyzi; Kaymakcı, Nuretdin; Çakır, Şerafeddin; Kaymakcı, Nuretdin (Elsevier BV, 2003-7)
The North Anatolian Fault Zone (NAFZ) bifurcates into three branches in the Marmara Region, which is a transition zone between the strike-slip tectonics manifested by the NAFZ and the N-S directed extensional regime of western Anatolia. The southern Marmara region is characterized by the middle and the southern branches while the northern branch controls the north Marmara region. The south Marmara region is characterized by approximately E-W trending rhomb-like horst and graben complexes bounded by strike s...
Neo- and seismo-tectonic characteristics of the Yenigediz (Kütahya) area
Gürboğa, Şule; Koçyiğit, Ali; Department of Geological Engineering (2011)
Erdoğmuş-Yenigediz graben is one of the major structural elements of Akşehir-Simav Fault System (ASFS), which is a major extensional structure in the southwestern Anatolian extensional neotectonic province (SWAEP). It is about 6-10-km-wide, 15-km-long and approximately ENE-trending and is actively growing structure as indicated by the 1970.03.28 (Mw= 7.2) Gediz earthquake. The graben is characterized by two distinct units, separated by an angular unconformity: (i) Miocene-middle Pliocene Arıca formation and...
Citation Formats
M. E. Ayhan and A. Kocyigit, “Displacements and Kinematics of the February 1, 1944 Gerede Earthquake (North Anatolian Fault System, Turkey): Geodetic and Geological Constraints,” TURKISH JOURNAL OF EARTH SCIENCES, pp. 285–311, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/65607.