Abstract In this study, the possible changes in microbial communities after the occurrence of an earthquake were investigated. To this end, the effects of the 2016 Gyeongju earthquake (ML 5.8) on the microbial communities in nearby aquifers were analyzed together with associated hydrochemistry data. Fourteen water samples were collected from two types of wells (alluvial and fractured rock formation); hydrogeochemical parameters, groundwater level, radon concentration, strontium isotopes, and microbiological features were monitored. The results obtained for microbial compositions and special bacteria were consistent with the hydrochemical results. Distinctive microbial communities in groundwater samples taken adjacent to the earthquake epicenter were also observed. The predominant bacteria in most samples were Pseudomonas and Flavobacterium. Radon concentrations, helium isotopes, and the helium/neon ratio showed anomalies in one well (KW8) compared to microbial composition data. Strontium data indicated that the study site may have been affected by seawater intrusion; this was corroborated by the microbiological features of archaea. The results indicate that an earthquake can change the number of species or their abundance in groundwater ecosystems. Therefore, microbial features might be a good additional indicator for analyzing the effects of earthquakes on groundwater, together with major chemical parameters such as radon, strontium, and helium. The microbiological features indicate that levels of bacteria such as Pseudomonas and Flavobacterium in the groundwater were highly correlated with the Gyeongju earthquake and the associated hydrochemical data.

中文翻译：

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地震对地下水生态系统中细菌和古菌群落的影响

摘要 本研究考察了地震发生后微生物群落可能发生的变化。为此，分析了 2016 年庆州地震 (ML 5.8) 对附近含水层微生物群落的影响以及相关的水化学数据。从两种类型的井（冲积岩层和裂隙岩层）中收集了 14 个水样；监测了水文地球化学参数、地下水位、氡浓度、锶同位素和微生物特征。微生物组成和特殊细菌的结果与水化学结果一致。在地震震中附近采集的地下水样品中也观察到了独特的微生物群落。大多数样品中的优势细菌是假单胞菌和黄杆菌。与微生物组成数据相比，氡浓度、氦同位素和氦/氖比在一个井 (KW8) 中显示异常。锶数据表明研究地点可能受到海水入侵的影响；古细菌的微生物特征证实了这一点。结果表明，地震可以改变地下水生态系统中的物种数量或其丰度。因此，微生物特征可能是分析地震对地下水影响的一个很好的附加指标，以及氡、锶和氦等主要化学参数。微生物学特征表明，地下水中假单胞菌和黄杆菌等细菌的含量与庆州地震和相关的水化学数据高度相关。与微生物组成数据相比，氦/氖比在一口井 (KW8) 中显示异常。锶数据表明研究地点可能受到海水入侵的影响；古细菌的微生物特征证实了这一点。结果表明，地震可以改变地下水生态系统中的物种数量或其丰度。因此，微生物特征可能是分析地震对地下水影响的一个很好的附加指标，以及氡、锶和氦等主要化学参数。微生物学特征表明，地下水中假单胞菌和黄杆菌等细菌的含量与庆州地震和相关的水化学数据高度相关。与微生物组成数据相比，氦/氖比在一口井 (KW8) 中显示异常。锶数据表明研究地点可能受到海水入侵的影响；古细菌的微生物特征证实了这一点。结果表明，地震可以改变地下水生态系统中的物种数量或其丰度。因此，微生物特征可能是分析地震对地下水影响的一个很好的附加指标，以及氡、锶和氦等主要化学参数。微生物学特征表明，地下水中假单胞菌和黄杆菌等细菌的含量与庆州地震和相关的水化学数据高度相关。