Region-Time-Magnitude Analyses of the Seismicity in and around the Central Anatolian Region and Current Earthquake Potential

Öz

The purpose of this study is to make detailed statistical analyses of earthquake occurrences in and around the Central Anatolian Region of Turkey and to forecast the possible earthquake regions in the future. In this scope, by performing the region-time-magnitude analyses of seismotectonic variables such as Mc-value, b-value, Dc-value, Z-value, the current/future earthquake potential was defined. b-value was computed as 1.26±0.07 by taking Mc=2.6 and this large value indicates that the earthquakes with small magnitude are dominant. Dc-value was calculated as 1.31±0.03 and this relatively small value shows that distance between the epicenters approaches the diameter of cluster, and earthquake activity is more clustered in larger regions/at smaller scales. Anomaly regions with low b-value and large Z-value at the beginning of 2019 were found in and around Tuz Gölü Fault Zone, Central Anatolian Fault Zone, Salanda and Niğde faults. As an important result, these regions may be considered as the most likely regions for strong/large earthquakes in the future.

Anahtar Kelimeler

• Central Anatolia,b-value,Dc-value,Z-value,Earthquake potential

Orta Anadolu Bölgesi ve Civarındaki Depremselliğin Bölge-Zaman-Magnitüd Analizleri ve Güncel Deprem Potansiyeli

Öz

Bu çalışmanın amacı, Türkiye’nin Orta Anadolu Bölgesi ve civarındaki deprem oluşumlarının detaylı istatistiksel analizlerini yapmak ve gelecekteki olası deprem bölgelerini tahmin etmektir. Bu kapsamda, Mc-değeri, b-değeri, Dc-değeri, Z-değeri gibi sismotektonik değişkenlerin bölge-zaman-magnitüd analizleri yapılarak, güncel/gelecek deprem potansiyeli ortaya konulmuştur. Mc=2.6 alınarak b=1.26±0.07 olarak hesaplanmıştır. Bu büyük değer küçük magnitüdlü depremlerin baskın olduğuna işaret etmektedir. Dc-değeri 1.31±0.03 olarak hesaplanmıştır ve bu nispeten küçük değer, episantrlar arasındaki uzaklığın kümelenme çapına yaklaştığını ve deprem aktivitesinin daha küçük ölçeklerde veya daha büyük alanlarda kümelendiğini göstermektedir. 2019 yılı başında düşük b-değerli ve yüksek Z-değerli anomali bölgeleri, Tuz Gölü Fay Zonu ve civarında, Orta Anadolu Fay Zonunda, Salanda ve Niğde faylarında gözlenmiştir. Önemli bir sonuç olarak, bu bölgeler gelecekteki büyük/güçlü depremler için en olası bölgeler olarak düşünülebilir.

Anahtar Kelimeler

• Orta Anadolu,b-değeri,Dc-değeri,Z-değeri,Deprem potansiyeli

Kaynakça

1. Ali S.M., 2016. Statistical analysis of seismicity in Egypt and its surroundings, Arab. J. Geosci. 9, 52, doi.org/10.1007/s12517-015-2079-x.
2. Bozkurt E., 2001. Neotectonics of Turkey-a synthesis, Geodin. Acta 14, 3-30, doi.org/10.1016/S0985-3111(01)01066-X.
3. Chen C.C., Wang W.C., Chang Y.F., Wu Y.M., Lee Y.H., 2006. A correlation between the b-value and the fractal dimension from the aftershock sequence of the 1999 Chi-Chi, Taiwan, earthquake, Geophys. J. Int. 167, 1215-1219, doi.org/10.1111/j.1365-246X.2006.03230.x.
4. Chiba K., 2019. Spatial and temporal distributions of b-values related to long-term slow-slip and low-frequency earthquakes in the Bungo Channel and Hyuga-nada regions, Japan, Tectonophysics 757, 1-9, doi.org/10.1016/j.tecto.2019.02.021.
5. Console R., Montuori C., Murru M., 2000. Statistical assessment of seismicity patterns in Italy: Are they precursors of subsequent events? J. Seismol. 4, 435-449, doi.org/10.1023/A:1026540018598.
6. Frohlich C., Davis S., 1993. Teleseismic b-values: Or, much ado about 1.0, J. Geophys. Res. 98(B1), 631-644, doi.org/10.1029/92JB01891.
7. Gentili S., Peresan A., Talebi M., Zare M., Giovambattista R.D., 2019. A seismic quiescence before the 2017 Mw 7.3 Sarpol Zahab (Iran) earthquake: Detection and analysis by improved RTL method, Phys. Earth Planet. Inter. 290, 10-19, doi.org/10.1016/j.pepi.2019.02.010.
8. Grassberger P., Procaccia I., 1983. Measuring the strangeness of strange attractors, Physica D: Nonlinear Phenomena 9(1-2), 189-208, doi.org/10.1016/0167-2789(83)90298-1.

9. Gutenberg R., Richter C.F., 1944. Frequency of earthquakes in California, B. Seismol. Soc. Am. 34, 185-188, doi.org/10.1038/156371a0.
10. Hirata T., 1989. Correlation between the b-value and the fractal dimension of earthquakes, J. Geophys. Res. 94, 7507-7514, doi.org/10.1029/JB094iB06p07507.
11. Kagan Y.Y., 2007. Earthquake spatial distribution: the correlation dimension, Geophys. J. Int. 168, 1175-1194.
12. Kahraman S., Baran T., Saatci İ.A., Salk M., 2008. The effect of regional borders when using the Gutenberg-Richter model, case study: Western Anatolia, Pure Appl. Geophys. 165, 331-347, doi.org/10.1007/s00024-008-0306-z.
13. Katsumata K., 2011. Precursory seismic quiescence before the Mw = 8.3 Tokachi‐oki, Japan, earthquake on 26 September 2003 revealed by a re‐examined earthquake catalog, J. Geophys. Res. 116, B10307, doi.org/10.1029/2010JB007964.
14. Oncel A.O., Wilson T.H., 2002. Space-time correlations of seismotectonic parameters and examples from Japan and Turkey preceding the İzmit earthquake, B. Seismol. Soc. Am. 92, 339-350, doi.org/10.1785/0120000844.
15. Oncel A.O., Wilson T.H., 2004. Correlation of seismotectonic variables and GPS strain- measurements in western Turkey, J. Geophys. Res. 109(B11), B11306. doi.org/10.1029/2004JB003101.
16. Ozmen B., Bayrak E., Bayrak Y., 2014. An investigation of seismicity for the Central Anatolia region, Turkey, J. Seismol. 18(3), 345-356, doi:10.1007/s10950-013-9411-2.
17. Ozmen B., 2015. Assessment of the statistical earthquake hazard parameters for the Central Anatolia region, Turkey, Arab. J. Geosci. 8, 6341-6351, doi.org/10.1007/s12517-014-1591-8.
18. Ozsayin E., Dirik K., 2007. Quaternary activity of the Cihanbeyli and Yeniceoba fault zones: İnönü-Eskişehir fault system, Central Anatolia, Turk. J. Earth Sci. 16, 471-492.
19. Ozturk S., 2011. Characteristics of Seismic Activity in the Western, Central and Eastern Parts of the North Anatolian Fault Zone, Turkey: Temporal and Spatial Analysis, Acta Geophys. 59(2), 209-238, doi.org/10.2478/s11600-010-0050-5.
20. Ozturk S., 2012. Statistical correlation between b-value and fractal dimension regarding Turkish epicentre distribution, Earth Sci. Res. J. 16(2), 103-108.
21. Ozturk S., 2013. A statistical assessment of current seismic quiescence along the North Anatolian Fault Zone: Earthquake precursors, Austrian J. Earth Sci. 106(2), 4-17.
22. Ozturk S., 2015. A study on the correlations between seismotectonic b-value and Dc-value, and seismic quiescence Z-value in the Western Anatolian region of Turkey, Austrian J. Earth Sci. 108(2), 172-184, doi.org/10.17738/ajes.2015.0019.
23. Ozturk S., 2017. Space-time assessing of the earthquake potential in recent years in the eastern Anatolia region of Turkey, Earth Sci. Res. J. 21(2), 67-75, doi.org /10.15446/esrj.v21n2.50889
24. Ozturk S., 2018. Earthquake hazard potential in the Eastern Anatolian region of Turkey: seismotectonic b and Dc-values and precursory quiescence Z-value, Front. Earth Sci. 12(1), 215-236, doi.org/10.1007/s11707-017-0642-3.
25. Öztürk S., 2009. Deprem tehlikesi ve artçı şok olasılığı değerlendirme yöntemlerinin Türkiye’deki depremlere bir uygulaması. Doktora Tezi, Karadeniz Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Trabzon, 346s.
26. Pailoplee S., Choowong M., 2014. Earthquake frequency-magnitude distribution and fractal dimension in mainland Southeast Asia, Earth Planets Space 66, 8, doi.org/10.1186/1880-5981-66-8 .
27. Polat O., Gok E., Yilmaz D., 2008. Earthquake hazard of the Aegean Extension region (West Turkey), Turk. J. Earth Sci. 17, 593-614.
28. Radziminovich N.A., Miroshnichenko A.I., Zuev F.L., 2019. Magnitude of completeness, b-value, and spatial correlation dimension of earthquakes in the South Baikal Basin, Baikal Rift System, Tectonophysics 759, 44-57, doi.org/10.1016/j.tecto.2019.04.002.
29. Reasenberg P.A., 1985. Second-order moment of Central California seismicity, 1969-1982, J. Geophys. Res. 90(B7), 5479-5495, doi.org/10.1029/JB090iB07p05479.
30. Rodriguez-Perez Q., Zuniga F.R., 2018. Imaging b-value depth variations within the Cocos and Rivera plates at the Mexican subduction zone, Tectonophysics 734-735, 33-43, doi.org/10.1016/j.tecto.2018.03.019.
31. Roy S., Ghosh U., Hazra S., Kayal J.R., 2011. Fractal dimension and b-value mapping in the Andaman-Sumatra subduction zone, Nat. Hazards 57, 27-37, doi.org/10.1007/s11069-010-9667-6.
32. Scholz C.H., 1968. The frequency-magnitude relation of microfracturing in rock and its relation to earthquakes, B. Seismol. Soc. Am. 58, 399-415.
33. Saroglu F., Emre O., Kuscu O., 1992. Active fault map of Turkey; General Directorate of Mineral Research and Exploration, Ankara, Turkey.
34. Singh C., 2016. Spatial variation of seismic b-values across the NW Himalaya, Geomat. Nat. Haz. Risk. 7(2), 522-530, doi.org/10.1080/19475705.2014.941951. Telesca L., Chen Ch-ch., 2019. Fractal and spectral investigation of the shallow seismicity in Taiwan, J. Asian Earth Sci. 174, 1-10, doi.org/10.1016/j.jseaes.2018.10.009.
35. Ulusay R., Tuncay E., Sonmez H., Gokceoglu C., 2004. An attenuation relationship based on Turkish strong motion data and iso-acceleration map of Turkey, Eng. Geol. 74(3-4), 265-291, doi.org/10.1016/j.enggeo.2004.04.002.
36. Utsu T., 1971. Aftershock and earthquake statistic (III): Analyses of the distribution of earthquakes in magnitude, time and space with special consideration to clustering characteristics of earthquake occurrence (1), J. Fac. Sci., Hokkaido Univ. Ser. VII (Geophysics) 3, 379-441.
37. Wiemer S., Wyss M., 1994. Seismic quiescence before the Landers (M=7.5) and Big Bear (6.5) 1992 earthquakes, B. Seismol. Soc. Am. 84(3), 900-916.
38. Wiemer S., Wyss M., 2000. Minimum magnitude of completeness in earthquake catalogs: Examples from Alaska, the Western United States, and Japan, B. Seismol. Soc. Am. 90(3), 859-869, doi.org/10.1785/0119990114.
39. Wiemer S., 2001. A software package to analyze seismicity: ZMAP, Seismol. Res. Lett. 72(2), 373-382, doi.org/10.1785/gssrl.72.3.373.
40. Wu Y.M., Chiao Y.L., 2006. Seismic quiescence before the 1999 Chi-Chi, Taiwan, MW7.6 Earthquake, B. Seismol. Soc. Am. 96(1), 321-327, doi.org/10.1785/0120050069.
41. Wyss M., Martirosyan A.H., 1998. Seismic quiescence before the M7, 1988, Spitak earthquake, Armenia, Geophys. J. Int. 134, 329-340.