Assessment of crustal thinning and tectonic stress distribution of Gülbahçe fault zone and its surroundings (İzmir, West Türkiye) using gravity and magnetic anomalies

Year 2022, Volume: 169 Issue: 169, 105 - 119, 05.12.2022

Oya Pamukçu Ayça Çırmık Fikret Doğru Ece Ünlü Barış Can Malaliçi

https://doi.org/10.19111/bulletinofmre.1029265

Abstract

Gülbahçe Fault Zone (GFZ) is a significant tectonic structure and seismic source for İzmir city and its surroundings. The major earthquakes occurred at the surroundings of GFZ are 2005 Seferihisar, 2020 Samos Island-Aegean Sea and 2021 Seferihisar earthquakes. In this study, the crustal thinning and tectonic stress distribution of GFZ and its surroundings were analyzed by using the new gravity and magnetic data. The correspondence analysis was applied by appraising together the magnetic and free-air anomaly data. Moreover, the average density of the subsurface structure was calculated by applying the Parasnis method. The deviatoric stress calculation was executed and the change of the physical properties that controls the gravity and magnetic anomaly of the crustal structure of the GFZ and its surroundings from north to south was investigated. Therefore, the average density values, which were obtained from gravity anomalies, were computed as 2.59 gr / cm3 in the north of the study region and it decreased to 2.06, 1.8 and 1.49 gr / cm3 towards to the south. The freeair gravity anomaly values were between 0-70 mGal and the magnetic anomalies were between -450-150 nT. The deviatoric stress values were between -0.2-0.1 MPa.

Keywords

Bouguer Gravity Anomaly, Gülbahçe Fault Zone (GFZ), Magnetic, Microgravity, Parasnis Method.

Supporting Institution

In this study the microgravity and magnetic data of the projects (Project No: 2018.KB.FEN.010) funded by Dokuz Eylül University Scientific Research Project and The Scientific and the Technological Research Council of Turkey (TUBITAK) (Project No: 108Y285) were used.

Project Number

Project No: 2018.KB.FEN.010-Project No: 108Y285

References

• Aadnoy, B., Looyeh, R. 2019. Petroleum Rock Mechanics: Drilling Operations and Well Design. Gulf Professional Publishing. 460.
• Akıncı, A., Eyidoğan, H., Göktürkler, G., Akyol, N., Ankaya, O. 2000. İzmir ili çevresinin depremselliği ve deprem tehlikesinin incelenmesi. Batı Anadolu’nun Depremselliği Sempozyumu (BADSEM 2000) İzmir, Bildiri Kitabı, 231-238 (in Turkish).
• Aktuğ, B., Kılıçoğlu, A. 2006. Recent crustal deformation of Izmir, Western Anatolia and surrounding regions as deduced from repeated GPS measurements and strain field. Journal of Geodynamics 41, 471-484.
• Ambraseys, N. N. 1988. Engineering seismology. Earthquake Engineering Structural Dynamical 17, 1–105.
• Arslan, S., Akın, U., Alaca, A. 2010. Gravite verileri ile Türkiye' nin kabuk yapısının incelenmesi. Bulletin of the Mineral Research and Exploration 140, 57-73.
• Baba, A, Şaroğlu, F., Akkuş, I., Özel, N., Yeşilnacar, M. İ., Nalbantçılar, M. T., Demir, M. M., Gökçen, G., Arslan, Ş., Dursun, N., Uzelli, T., Yazdani, H. 2019. Geological and hydrogeochemical properties of geothermal systems in the southeastern region of Turkey. Geothermics 78, 255-271.
• Barka, A. A., Kadinsky Cade, K. 1988. Strike‐ slip fault geometry in Turkey and its influence on earthquake activity. Tectonics 7, 663-684.
• Bozkurt, E. 2001. Neotectonics of Turkey- a synthesis. Geodinamica Acta 14, 3-30.
• Çetiner, M. 2012. İzmir ve çevresindeki mikrogravite verilerinin değerlendirilmesi. MSc Thesis, Dokuz Eylül University, The Graduate School of Nature and Applied Sciences, 78, İzmir.
• Çırmık, A., Ozdag, O. C., Doğru, F., Pamuk, E., Gonenc, T., Pamukcu, O., Akgün, M., Arslan, A. T. 2016. The soil behaviours of the GNSS station. Earth Sciences 5(5), 70-81.
• Çırmık, A., Pamukçu, O. 2017. Clarifying the interplate main tectonic elements of Western Anatolia, Turkey by using GNSS velocities and Bouguer gravity anomalies. Journal of Asian Earth Science 148, 294-304.
• Çırmık, A., Doğru, F., Gönenç, T., Pamukçu, O. 2017a. The stress / strain analysis of kinematic structure at Gülbahçe Fault and Uzunkuyu Intrusive (İzmir, Turkey). Pure and Applied Geophysics 174(3), 1425-1440.
• Çırmık, A., Pamukçu, O., Gönenç, T., Kahveci, M., Şalk, M., Herring, T. 2017b. Examination of the kinematic structures in İzmir (Western Anatolia) with repeated GPS observations (2009, 2010 and 2011). Journal of African Earth Sciences 126, 1-12.
• De Ritis, R., Ventura, G., Chiappini, M., Carluccio, R., Von Frese, R. 2010. Regional magnetic and gravity anomaly correlations of the Southern Tyrrhenian Sea. Physics of the Earth and Planetary Interiors 181(1-2), 27-41.
• Dewey, J. F., Şengör, A. M. C. 1979. Aegean and surrounding regions: complex multi plate and continuum tectonics in a convergent zone. Geological Society of America Bulletin Part 1 90, 84-92.
• Doğru, F., Pamukcu, O., Ozsoz, I. 2017. Application of tilt angle method to the Bouguer gravity data of Western Anatolia. Bulletin of the Mineral Research and Exploration 155(155), 213-222.
• Doğru, F., Pamukcu, O., Gonenc, T., Yildiz, H. 2018. Lithospheric structure of western Anatolia and the Aegean Sea using GOCE-based gravity field models. Bollettino di Geofisica Teorica ed Applicata 59(2), 135-160.
• Doğru, F., Pamukçu, O. 2019. Analysis of gravity disturbance for boundary structures in the Aegean Sea and Western Anatolia. Geofizika 36(1), 53-76.
• Emre, O., Ozalp, S., Dogan, A., Ozaksoy, V., Yıldırım, C., Goktas, F. 2005. İzmir yakın çevresinin diri fayları ve deprem potansiyelleri. Maden Tetkik Arama Genel Müdürlüğü, Rapor No: 10754, Ankara (unpublished).
• Erbek, E., Dolmaz, M. N. 2014. Geophysical researches (gravity and magnetic) of the Eratosthenes Seamount in the eastern Mediterranean Sea. Acta Geophysica 62(4), 762-784.
• Heiskanen, W. A., Moritz, H. 1967. Physical geodesy. Bulletin Geodesique 86, 491–492.
• Hinze, W. J., Von Frese, R. R. B., Saad, A. H. 2013. Gravity and Magnetic Exploration Principles, Practices and Applications. Cambridge University Press, 502.
• Göktaş, F. 2016. Ildır Körfezi güneyindeki bölgenin Neojen stratigrafisi Çeşme Yarımadası, Batı Anadolu. Türkiye Jeoloji Bülteni 59(3), 299–321 (in Turkish).
• Ketin, İ. 1948. Uber die tektonisch - mechanischen Folgerungenaus den grossen Anotolischen Erdbeben des letzten Dezenniums. Geologische Rundschau 36, 77-83.
• Malaliçi, B. C. 2019. Gülbahçe fayı ve çevresinin jeodinamik yapısının irdelenmesi. MSc Thesis, Dokuz Eylül University, The Graduate School of Nature and Applied Sciences, 77, İzmir.
• McKenzie, D. 1972. Active tectonics of the Mediterranean region. Geophysical Journal of the Royal Astronomical Society 30, 109-185.
• Mount, V. S., Suppe, J. 1987. State of stress near the San Andreas fault: implications for wrench tectonics. Geology 15(12), 1143-1146.
• Ocakoğlu, N., Demirbağ, E., Kuşçu, İ. 2005. Neotectonic structures in İzmir Gulf and surrounding regions (western Turkey): evidences of strike-slip faulting with compression in the Aegean extensional regime. Marine Geology 219(2-3), 155-171.
• Pamuk, E. 2019. Investigating edge detection, Curie point depth, and heat flow using EMAG2 magnetic and EGM08 gravity data in the northern part of Eastern Anatolia, Turkey. Turkish Journal of Earth Sciences 28(6), 805-821.
• Pamukçu, O., Akçığ, Z., Demirbaş, Ş., Zor, E. 2007. Investigation of crustal thickness in eastern Anatolia using gravity, magnetic and topographic data. Pure Applied Geophysics 164, 2345-2358.
• Pamukçu, O., Yurdakul, A. 2008. Isostatic compensation in Western Anatolia with estimate of the effective elastic thickness. Turkish Journal of Earth Sciences 17, 545-557.
• Pamukçu, O. A., Akçığ, Z. 2011. Isostasy of the Eastern Anatolia (Turkey) and discontinuities of its crust. Pure and Applied Geophysics 168(5), 901-917.
• Pamukçu, O., Gönenç, T., Yurdakul, A., Özyalın, Ş., Sözbilir, H. 2012. Application of boundary analysis and modelling methods on Bouguer gravity data of the Gediz Graben and surrounding area in Western Anatolia and its tectonic implications. Journal of the Balkan Geophysical Society 15, 19-30.
• Pamukçu, O., Gönenç, T., Yurdakul, A., Kahveci, M. 2013. Sismik riski yüksek olan İzmir - Karaburun’un güneyinde yapılmış mikrogravite ve GPS çalışmaları. Jeofizik 18, 59-66 (in Turkish).
• Pamukçu, O., Gönenç, T., Çirmik, A., Sindirgi, P., Kaftan, I., Akdemir, Ö. 2015. Investigation of vertical mass changes in the south of Izmir (Turkey) by monitoring microgravity and GPS / GNSS methods. Journal of Earth System Science 124(1), 137-148.
• Pamukçu, O. 2017. Stress analysing with gravity data. 3. International Conference on Engineering and Natural Science, 3 - 7 May 2017, Budapest, 600-602.
• Pamukçu, O., Gönenç, T., Çırmık, A., Pamukçu, Ç., Ertürk, N. 2019. The geothermal potential of Büyük Menderes Graben obtained by combined 2.5 - D normalized full gradient results. Pure and Applied Geophysics 176(11), 5003-5026.
• Parasnis, D. S. 1952. A study of rock densities in English Midlands. Geophysical Journal International 6, 252–271.
• Saleh, S., Jahr, T., Jentzsch, G., Saleh, A., Abou Ashour, N. M. 2006. Crustal evaluation of the northern Red Sea rift and Gulf of Suez, Egypt from geophysical data: 3-dimensional modeling. Journal of African Earth Sciences 45(3), 257–278.
• Sözbilir, H., Sümer, Ö., Uzel, B., Ersoy, Y., Erkül, F., İnci, U., Helvacı, C. Özkaymak, Ç. 2009. 17 - 20 Ekim 2005 - Sığacık Körfezi (İzmir) depremlerinin sismik jeomorfolojisi ve bölgedeki gerilme alanları ile ilişkisi, Batı Anadolu. Türkiye Jeoloji Bülteni, 52 (2), 217–238 (in Turkish).
• Sözbilir, H., Softa, M., Eski, S., Tepe, Ç., Akgün, M., Pamukçu, O., Çırmık, A., Utku, M., Özdağ, C. Ö., Özden, G., Özçelik, Ö., Evlek, D.A., Çakır, R., Baba, A., Uzelli, T. and Tatar O. 2020. 30 October 2020 Sisam (Samos) Earthquake (Mw: 6.9) Evaluation Report, Dokuz Eylül University Earthquake Research and Application Center (in Turkish).
• Şengör, A. M. C., Yılmaz, Y. 1981. Tethyan evolution of Turkey: a plate tectonic approach. Tectonophysics 75, 181-241.
• Şengör, A. M. C., Görür, N., Şaroğlu, F. 1985. Strike - slip faulting and related basin formation in zones of tectonic escape: Turkey as a case study. Special Publications of the Society of Economic Palaeontologists and Mineralogists 37, 227–264.
• Taymaz, T., Jackson, J., McKenzie, D. P. 1991. Active tectonics of the North and Central Aegean Sea. Geophysical Journal International 106, 433–490.
• Turcotte, D. L., Schubert, G. 2002. Geodynamics. Cambridge University Press, 456.
• USGS (United States Geological Survey earthquake catalog). https://earthquake.usgs.gov/earthquakes/search/. 1 June 2021.
• Uzel, B., Sözbilir, H. 2008. A first record of strike - slip basin in western Anatolia and its tectonic implication: The Cumaovası basin as an example. Turkish Journal of Earth Sciences 17, 559–591.
• Uzel, B., Sözbilir, H., Özkaymak, Ç. 2012. Neotectonic evolution of an actively growing superimposed basin in western Anatolia: the inner bay of Izmir, Turkey. Turkish Journal of Earth Sciences 21(4), 439-471.
• Von Frese, R. R. B., Hinze, W. J., Braile, L. W. 1982. Regional North American gravity and magnetic anomaly correlations. Geophysical Journal International 69, 145-761.
• Von Frese, R. R., Jones, M. B., Kim, J. W., Kim, J. H. 1997a. Analysis of anomaly correlations. Geophysics 62(1), 342-351.
• Von Frese, R. R., Jones, M. B., Kim, J. W., Li, W. S. 1997b. Spectral correlation of magnetic and gravity anomalies of Ohio. Geophysics 62(1), 365-380.
• Watts, A. B. 2001. Isostasy and Flexure of the Lithosphere. Cambridge University Press, 458.
• Xu, C., Wang, H. H., Luo, Z. C., Ning, J. S., Liu, H. L. 2015. Multilayer stress from gravity and its tectonic implications in urban active fault zone: a case study in Shenzhen, South China. Journal of Applied Geophysics 114, 174-182.