School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
Department of Geology, Kangwon National University, Chuncheon, 24341, Republic of Korea.
Sci Rep. 2024 Oct 29;14(1):25955. doi: 10.1038/s41598-024-77011-7.
Earthquakes have a significant impact on groundwater environments as well as human life. However, identifying active and affected zones from seismic events using isotopic and microbial diversity indicators remains a challenging frontier. To validate the applicability of this coupled method for real-time analysis, we analyzed thoron (Rn), radon (Rn), microbial community compositions, and hydrochemistry in groundwater samples during the 2017 Pohang earthquake for the first time. We observed the detection of Rn in groundwater right before the aftershocks, with a high correlation to Rn concentrations. This indicates that Rn and Rn can serve as reliable seismic indicators for real-time analysis. The microbial data can assist in identifying affected groundwater zones, particularly when real-time detection of Rn is not feasible. At the phylum level, Peregrinibacteria and Firmicutes were only found in samples with detected thoron. At the genus level, hydrogen-oxidizing or sulfur-oxidizing bacteria could serve as indicators of active zones. Two statistical analyses, self-organizing map (SOM) and principal component analysis (PCA) using hydrochemical parameters, also correlated with the results from these coupled indicators. This study demonstrates the theoretical and practical applicability of Rn, Rn, and microbial community compositions as new multi-faceted ecological indicators, whether for real-time analysis or otherwise.
地震对地下水环境和人类生活都有重大影响。然而，利用同位素和微生物多样性指标来识别地震事件中的活动区和受灾区仍然是一个具有挑战性的前沿领域。为了验证这种耦合方法在实时分析中的适用性，我们首次分析了 2017 年浦项地震期间地下水中的氡（Rn）、钍（Rn）、微生物群落组成和水化学。我们观察到在余震前地下水中 Rn 的检测，与 Rn 浓度高度相关。这表明 Rn 和 Rn 可以作为实时分析的可靠地震指标。微生物数据可以帮助识别受灾区地下水，特别是在实时检测 Rn 不可行时。在门水平上，仅在检测到氡的样品中发现 Peregrinibacteria 和Firmicutes。在属水平上，氢氧化或硫氧化细菌可以作为活动区的指示菌。使用水文化学参数的自组织映射（SOM）和主成分分析（PCA）两种统计分析方法也与这些耦合指标的结果相关。本研究证明了 Rn、Rn 和微生物群落组成作为新的多方面生态指标的理论和实际适用性，无论是实时分析还是其他方面。
