Isotopic responses of hot and cold groundwaters to the 2023 Kahramanmaraş earthquakes: Evidence from oxygen-18 (δ18O), deuterium (δ2H), and tritium (3H, TU)
JOURNAL OF HYDROLOGY, ss.1-69, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.jhydrol.2026.136298
- Dergi Adı: JOURNAL OF HYDROLOGY
- Derginin Tarandığı İndeksler: Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Scopus, Science Citation Index Expanded (SCI-EXPANDED), Artic & Antarctic Regions, BIOSIS, Compendex, Environment Index, Geobase, INSPEC
- Sayfa Sayıları: ss.1-69
- Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet
Özet
The extensive surface ruptures created by the February 6, 2023, Kahramanmaraş earthquake sequence (Mw 7.7 and Mw 7.6) along the East Anatolian Fault Zone have provided data for the detailed evaluation of earthquake-induced hydrogeochemical responses in groundwater systems. This study investigates the spatial variability of groundwater responses in a structurally complex tectonic setting by assessing post-seismic changes in hot and cold springs using stable isotopes (δ18O and δ2H) and radioactive isotope (3H) data. The isotopic compositions indicate that the studied waters are mainly of meteoric origin and lie between the Global Meteoric Water Line and the Mediterranean Meteoric Water Line. Tritium data were further evaluated using a piston-flow model and Monte Carlo uncertainty analysis to provide a comparative assessment of apparent ground-water ages. Comparison of isotope data before and after the earthquake showed that the groundwater responses were very heterogeneous spatially. Three typical response patterns were identified: (i) large changes in tritium with no associated shifts in stable isotopes, (ii) large shifts in stable isotopes with no detectable changes in tritium, and (iii) no measurable change in either tracer. The different response patterns suggest that stable isotopes and tritium can be used as tracers for different characteristics of the groundwater system and may have different responses to seismic disturbances. Variable isotope responses were observed even for springs near the mapped surface rupture, suggesting that proximity to the rupture alone does not govern post-seismic hydrogeochemical behaviour. Instead, the observed responses reflect the influence of local geological and hydrogeological conditions on the groundwater systems. Results emphasise the utility of combining stable isotopes and tritium to characterise pre- to post-earthquake differences in groundwater systems and provide a regional isotopic baseline for future post-seismic hydrogeochemical studies in tectonically active areas.