The 2017 July 20M w 6.6 Bodrum-Kos earthquake illuminates active faulting in the Gulf of Gökova, SW Turkey

Karasözen, Ezgi; Nissen, Edwin; Büyükakpınar, Pinar; Cambaz, Musavver Didem; Kahraman, Metin; Ertan, Esra Kalkan; Abgarmi, Bizhan; Bergman, Eric; Ghods, Abdolreza; Özacar, Atilla Arda
July 2018
Geophysical Journal International;Jul2018, Vol. 214 Issue 1, p185
Academic Journal
The 2017 July 20 Bodrum-Kos earthquake (Mw 6.6) is the largest instrumentally recorded earthquake in the Gökova graben, one of the primary physiographic features of SW Turkey. Using seismology and satellite geodesy, we investigate its source characteristics, aftershock distribution, relationship with earlier instrumental seismicity, and association with known surface faulting. We show that the earthquake ruptured a planar (non-listric) normal fault that dips gently (~37°) northwards beneath the northern Gulf of Gökova coastline, initiating at a depth of ~11 km and rupturing upwards and bilaterally. Aftershocks concentrate around (but not necessarily on) the western, eastern and downdip edges of the ~25 km-long rupture plane, and have maximum focal depths of ~15 km. The main shock surface trace bounds a bathymetric ridge east of Kos island, and may be one of the several faults imaged previously in this area using seismic profiling and multibeam sonar. The fault thus lies within the hangingwall of the lower-angle (~20° N-dipping) South Datça fault, which it presumably cross-cuts at depth. Through calibrated relocations,we confirmthat sequences of moderate (Mw 5-5.5) earthquakes in 1989, 2004 and 2005 occurred in the eastern and central Gulf of Gökova, many of them likely within the hangingwall of the S-dipping Gökova fault. Overall, our results indicate a switch from dominant S-dipping normal faulting in the eastern graben to dominant N-dipping faulting in the west, but we find no support for a proposed NE-SW-trending left-lateral fault in the central Gulf; most colocated focal mechanisms involve ~E-W normal faulting. Finally, the Bodrum-Kos main shock adds to growing set of examples from across the Aegean region of large normal faulting earthquakes that cut the seismogenic layer as simple planar structures.


Related Articles

  • Anisotropy and rift systems. Savage, Martha Kane // Nature;9/8/1994, Vol. 371 Issue 6493, p105 

    Focuses upon the study of S. Gao and others on the direction of asthenospheric flow beneath a continental rift. Theory of plate tectonics; Explanation of seismic anisotropy; Causes and application of anisotropy; Method and results of the study; Questions raised about anisotropy and continental...

  • Role of transverse tectonics in the Himalayan collision: Further evidences from two contemporary earthquakes. Dasgupta, Sujit; Mukhopadhyay, Basab; Mukhopadhyay, Manoj; Nandy, D. // Journal of the Geological Society of India;Feb2013, Vol. 81 Issue 2, p241 

    Two contemporary earthquakes originating in the central Himalayan arc and its foredeep (Sikkim earthquake of 18.09.2011, M 6.9, h: 10-60 (?) km and Bihar-Nepal earthquake of 20.08.1988, Mw 6.8, h: 57 km) are commonly associated with transverse lineaments/faults traversing the region. Such...

  • Eastern Turkey shakes. Zukerman, Wendy // New Scientist;10/29/2011, Vol. 212 Issue 2836, p4 

    The article discusses earthquakes in Turkey and examines the Bitlis suture zone, an area where the Anatolian plate is compressed by both the Arabian and Eurasian tectonic plates.

  • Crustal Structure of Turkey from Aeromagnetic, Gravity and Deep Seismic Reflection Data. Ates, Abdullah; Bilim, Funda; Buyuksarac, Aydin; Aydemir, Attila; Bektas, Ozcan; Aslan, Yasemin // Surveys in Geophysics;Sep2012, Vol. 33 Issue 5, p869 

    In this paper, aeromagnetic and gravity anomalies obtained from the General Directorate of Mineral Research and Exploration were subjected to upward continuation to 3 km from the ground surface to suppress shallow effects and to expose only regional, deep sources. Then, a reduction to pole (RTP)...

  • Earthquakes and slip rate of the southern Sagaing fault: insights from an offset ancient fort wall, lower Burma (Myanmar). Wang, Yu; Sieh, Kerry; Aung, Thura; Min, Soe; Khaing, Saw Ngwe; Tun, Soe Thura // Geophysical Journal International;Apr2011, Vol. 185 Issue 1, p49 

    Field investigations of an ancient fortress wall in southern Myanmar reveal an offset of ∼6 m across the Sagaing fault, the major right-lateral fault between the Sunda and Burma plates. The fault slip rate implied by offset of this 16th-century fortress is between 11 and 18 cm yr. A...

  • Geo-archeology at Khajnawar in Western Uttar Pradesh plain. Thakur, V. C.; Pandey, A. K.; Nautiyal, C. M.; Sundriyal, Y. P.; Khanduri, B. M.; Shinde, D. P.; Suresh, N.; Singhvi, A. K. // Current Science (00113891);4/25/2010, Vol. 98 Issue 8, p1112 

    Khajnawar village in Saharanpur district of western Utter Pradesh is inhabited over the remains of an ancient archaeological settlement. Field observations and archaeological investigation reveal two periods of settlement: settlement I with grey ware and iron objects and settlement II with...

  • New Updated Classification of Shallow Earthquakes Based on Faulting Style. Salih Al-Heety, Emad Abulrahman Mohammed // Iraqi Journal of Science;2020, Vol. 61 Issue 1, p103 

    Earthquakes occur on faults and create new faults. They also occur on normal, reverse and strike-slip faults. The aim of this work is to suggest a new unified classification of Shallow depth earthquakes based on the faulting styles, and to characterize each class. The characterization criteria...

  • Seismicity of Kachchh and Shillong Plateau and their connectivity to plate margins. Mishra, D. // Journal of Seismology;Jan2016, Vol. 20 Issue 1, p265 

    Kachchh and the Shillong plateau are located in the intraplate region but are seismically active almost on par with the plate boundaries. This is an enigma and requires suitable explanation. Bouguer anomaly and isostatic residual anomaly maps of Kachchh and adjoining region in Pakistan derived...

  • An approach to jointly invert hypocenters and 1D velocity structure and its application to the Lushan earthquake series. Qian, Hui; Mechie, James; Li, Haibing; Xue, Guangqi; Su, Heping; Cui, Xiang // Journal of Seismology;Jan2016, Vol. 20 Issue 1, p213 

    Earthquake location is essential when defining fault systems and other geological structures. Many methods have been developed to locate hypocenters within a 1D velocity model. In this study, a new approach, named MatLoc, has been developed which can simultaneously invert for the locations and...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics