In a study carried out within the scope of the ITU-BAP Rapid Support project no. 44774, chemical anomalies were detected in the spring waters before the Kahramanmaraş earthquakes. This study was completed by Prof.Dr. Sedat Inan and Dr. Nurettin Yakupoğlu from the ITU Department of Geological Engineering, in collaboration with Prof. Dr. Hasan Çetin from Çukurova University.

Understanding earthquake phenomena is always challenging. Search for reliable precursors of earthquakes are important but requires systematic and long-time monitoring employing multi-disciplinary techniques. Continuous monitoring as mentioned by İnan et al. (2007) no longer exists in the Kahramanmaraş region. Therefore, in search of possible precursors, we obtained commercially bottled spring waters dated before and after the earthquakes of 6 February 2023.

Hydrogeochemical precursors have been detected in commercially bottled natural spring waters (Ayran Spring) which are at a distance of about 100 km and 175 km from the epicenters of the Mw 7.7 and Mw 7.6 Kahramanmaraş (Türkiye) Earthquakes of 6 February 2023, respectively.It was observed that the deformation that occurred in the crust before these earthquakes caused changes in the cation/anion concentration in some commercially bottled spring waters (Ca2+, Mg2+, K+, Na+, Cl–, SO42–) through rock-water interaction (Figure 1). After electrical conductivity measurements of these water samples were made, anion/cation analyzes were performed with an ion chromatography device and reliable anomalies that could indicate crustal deformation before the earthquake were detected. Figure 1 shows the major ion content measured with the ion chromatography device of the pre- and post-earthquake samples collected from Ayran spring water located within the borders of Bahçe district of Osmaniye Province. A positive anomaly that lasted at least six months was detected before the Mw 7.7 and Mw 7.6 earthquakes that occurred on February 6, 2023. It is observed that these anomalies reach up to 4 times the normal value for each ion. An anomaly was also detected before the 20 February 2023 Hatay Mw 6.4 earthquake. It is observed that as of early March 2023, the major ion content of the spring water has decreased and reached its normal level. The article discussing the results of this study (İnan et al., 2023) has been submitted to the journal Natural Hazards and Earth Systems Science and is under publication.

Based on the results of this study and many others worldwide, It is believed that studying pre-earthquake crustal deformations with multidisciplinary methods and continuous observations will enable better understanding the earthquake process and reducing earthquake hazards.

Figure 1. Variations in major ions of the water samples from Ayran Spring (located in Osmaniye Province, Bahçe town) and possible relations with earthquakes (İnan et al. 2023)

REFERENCES

İnan, S., Ergintav, S., Saatçιlar, S., Tüzel, B. and Iravul, Y. (2007) Turkey makes major investments in earthquake research. EOS Transactions 88, 333–334, https://doi.org/10.1029/2007EO340002,

İnan, S., Balderer, W.P., Leuenberger-West, F., Yakan, H., Özvan, A., Freund, F.T. (2012) Springwater chemical anomalies prior to the Mw = 7.2 Van Earthquake (Turkey). Geochemical Journal 46, e11-e16. https://doi.org/10.2343/geochemj.1.0159

İnan, S., Çetin, H., and Yakupoğlu, N. (2023) Spring water anomalies before two consecutive earthquakes (Mw 7.7 and Mw 7.6) in Kahramanmaraş (Türkiye) on 6 February 2023. Natural Hazards and Earth Systems Science [preprint], in review. https://nhess.copernicus.org/preprints/nhess-2023-133/