10 Ağustos 2025 Mw 6.1 Sındırgı (Balıkesir) Depremi Sırasında Gözlenen Jeomanyetik Alan Değişimleri

Abstract

Batı Anadolu, aktif normal faylarla karakterize edilen genişlemeli bir tektonik rejime sahiptir. Bu çalışmada, 10 Ağustos 2025 tarihinde Balıkesir-Sındırgı yakınlarında meydana gelen Mw 6.1 büyüklüğündeki depremin eş-sismik jeomanyetik etkileri incelenmiştir. İznik (IZN) jeomanyetik gözlemevine ait 1 saniyelik H, D ve Z bileşenleri ile AFAD 1657 istasyonunun ivme kayıtları birlikte analiz edilmiştir. Ana şok sırasında tüm jeomanyetik bileşenlerde kısa süreli anomaliler belirlenmiştir. Genlik zarfı analizleri, enerji yoğunlaşmasının ilk yaklaşık 60 saniye içinde gerçekleştiğini göstermektedir. Manyetik piklerin, P ve S dalga varışları ile maksimum ivme değerleriyle zamansal uyumlu olduğu saptanmıştır. Kp, Hp30 ve SYM-H indeksleri jeomanyetik fırtına olmadığını göstermektedir. Sonuçlar, sinyallerin kabuksal elektromanyetik üretimden çok aletsel kaynaklı olabileceğini ortaya koymaktadır.

Keywords

• Batı Anadolu
• Sındırgı depremi
• Eş-sismik jeomanyetik değişim
• Jeomanyetik alan
• Aletsel yanıt

Geomagnetic Field Perturbations Observed During the 10 August 2025 Mw 6.1 Sındırgı (Balıkesir) Earthquake

Abstract

Western Anatolia is characterized by an extensional tectonic regime dominated by active normal fault systems. In this study, the co-seismic geomagnetic effects of the Mw 6.1 earthquake that occurred near Balıkesir-Sındırgı on 10 August 2025 were investigated. One-second resolution H, D, and Z components from the İznik (IZN) geomagnetic observatory were analyzed together with acceleration records from the AFAD 1657 station. During the main shock, transient anomalies were identified in all geomagnetic components. Envelope analyses indicate that the maximum energy concentration occurred within the first approximately 60 seconds. The magnetic peaks were found to be temporally consistent with the arrivals of P and S waves and the peak ground acceleration values. The Kp, Hp30, and SYM-H indices indicate the absence of a geomagnetic storm. The results suggest that the observed signals reflect an instrumental response to strong ground motion rather than crustal electromagnetic generation.

Keywords

• Western Anatolia
• Sındırgı earthquake
• Coseismic geomagnetic perturbations
• Geomagnetic field
• Instrumental response

References

1. Aydın N.G., 2024. Elazığ - Sivrice ve Gezin Civarının Yeraltı Yapısının Gravite Verileri Kullanılarak Modellenmesi, İstanbul Teknik Üniversitesi Lisansüstü Eğitim Enstitüsü, Doktora Tezi.
2. Bekler F.N., Demirci A., Bekler T., 2026. Recent Earthquake Activities and Seismic Sources in Northwestern Türkiye, Eng. Proc., 125, 2.
3. Büyüksaraç A., Avcil F., Alkan H., Işık E., Harirchian E., Özçelik A., 2025. Seismic Hazard Implications of the 2025 Balıkesir Earthquake of Mw 6.1 for Western Türkiye, GeoHazards, 6, 64.
4. Eleman F., 1965. The response of magnetic instruments to earthquake waves, J. Geomag. Geoelectr., 18(1), 43-72.
5. Emre Ö., Duman T.Y., Özalp S., Elmacı H., Olgun Ş., Şaroğlu F., 2013. 1/1.250.000 Ölçekli Türkiye Diri Fay Haritası, Maden Tetkik ve Arama Genel Müdürlüğü Özel Yayınlar Serisi, Ankara, Türkiye.
6. Emre Ö., Duman T.Y., Özalp S., Saroğlu F., Olgun S., Elmacı H., Çan T., 2018. Active fault database of Türkiye, Bull. Earthq. Eng., 16, 3229-3275.
7. Gao Y., Chen X., Hu H., Wen J., Tang J., Fang G., 2014. Induced electromagnetic field by seismic waves in Earth’s magnetic field, J. Geophys. Res. Solid Earth, 119, 5651-5685.
8. Gao Y., Hu H., 2010. Seismoelectromagnetic waves radiated by a double couple source in a saturated porous medium, Geophysical Journal International, 181, 873-896.

9. Gao Y., Jiang P., Xu Y., Jiang L., Cheng C-H., Zhao G., Tang J., Chen X., Han B., Chong J., Yao C., 2021. On magnetic disturbances induced by rotation of coil-type magnetometer driven by seismic waves, Geophysical Journal International, 226, 1948-1974.
10. Gao Y., Zhao G., Chong J., Klemperer S.L., Han B., Jiang F., Wen J., Chen X., Zhan Y., Tang J., Xiao Q., Wan L., 2020. Coseismic electric and magnetic signals observed during 2017 Jiuzhaigou Mw 6.5 earthquake and explained by electrokinetics and magnetometer rotation, Geophysical Journal International, 223, 1130-1143.
11. Guglielmi A., 1992. Elastomagnetic waves in a porous medium, Physica Scripta., 46, 433-434.
12. Hayakawa M., Ito T., Smirnova N., 1999. Fractal analysis of ULF geomagnetic data associated with the Guam earthquake on August 8, 1993, Geophys. Res. Lett., 26, 2797-2800.
13. Hu H., Gao Y., 2011. Electromagnetic field generated by a finite fault due to electrokinetic effect, J. Geophys. Res., 116, B08302.
14. Huang Q., 2002. One possible generation mechanism of co-seismic electric signals, Proc. Jpn. Acad. Ser. B, 78, 173-178.
15. Iyemori T., Kamei T., Tanaka Y., Takeda M., Hashimoto T., Araki T., Okamoto T., Watanabe K., Sumitomo N., Oshiman N., 1996. Coseismic geomagnetic variations observed at the 1995 Hyogokennanbu earthquake, J. Geomag. Geoelectr., 48, 1059-1070.
16. Johnston M.J.S., 1997. Review of Electric and Magnetic Fields Accompanying Seismic and Volcanic Activity, Surveys in Geophysics, 18, 441-476.
17. Johnston M.J.S., Sasai Y., Egbert G.D., Muller R.J., 2006. Seismomagnetic effects from the long-awaited 28 September 2004 M 6.0 Parkfield earthquake, Bull. Seismol. Soc. Am., 96(4B), 206-220.
18. Koshevaya S.V., Grimalsky V.V., Burlak G.N., Pérez Enríquez R., Kotsarenko A.N., 2001. Magnetic perturbations excited by seismic waves, Phys. Scr., 64, 172-176.
19. Kutoğlu Ş.H., Softa M., Akgün E., Nas M., Topal S., 2026. Analyzing Fault Reactivation Behavior Using InSAR, Stress Inversion, and Field Observations During the 2025 Sındırgı Earthquake Sequence, Simav Fault Zone, Western Türkiye, Sensors, 26, 760.
20. Masci F., Thomas J.N., 2016. Evidence of underground electric current generation during the 2009 L’Aquila earthquake: Real or instrumental?, Geophys. Res. Lett., 43, 6153-6161.
21. Matsushima M., Honkura Y., Oshiman N., Barış Ş., Tunçer M.K., Tank S.B., Çelik C., Takahashi F., Nakanishi M., Yoshimura R., Pektaş R., Komut T., Tolak E., Ito A., Iio Y., Işıkara A.M., 2002. Seismoelectromagnetic effect associated with the İzmit earthquake and its aftershocks, Bull. Seismol. Soc. Am., 92, 350-360.
22. Nenovski P., 2015. Experimental evidence of electrification processes during the 2009 L’Aquila earthquake main shock, Geophys. Res. Lett., 42, 7476-7482.
23. Ren H., Wen J., Huang Q., Chen X., 2015. Electrokinetic effect combined with surface-charge assumption: a possible generation mechanism of coseismic EM signals, Geophys, J. Int., 200, 835-848.
24. Soysal H., Sipahioğlu S., Kolçak D., Altınok Y., 1981. Türkiye ve çevresinin tarihsel deprem kataloğu, M.Ö. 2100-M.S. 1900, TÜBİTAK Proje No: TBAG 341, 87 s, İstanbul.
25. Ujihara N., Honkura Y., Ogawa Y., 2004. Electric and magnetic field variations arising from the seismic dynamo effect for aftershocks of the M7.1 earthquake of 26 May 2003 off Miyagi Prefecture, NE Japan, Earth Planets Space, 56, 115-123.
26. Zhao J., Gao Y., Cheng Q., Zhou G., Chen C-H., Zhang X., Sun Y., 2024. Numerical simulation of electromagnetic responses to an earthquake source due to the piezoelectric effect of ‘∞m’ symmetry, Journal of Geophysical Research: Solid Earth, 129, e2023JB027756.
27. Zhao J., Gao Y., Tang J., Klemperer S.L., Wen J., Chen C-H., Chong J., 2021. Electromagnetic field generated by an earthquake source due to motional induction in 3D stratified media, and application to 2008 Mw 6.1 Qingchuan earthquake, Journal of Geophysical Research: Solid Earth, 126, e2021JB022102.