Montiel-López David, Molina Sergio, Galiana-Merino Juan José, Gómez Igor, Kharazian Alireza, Soler-Llorens Juan Luís, Huesca-Tortosa José Antonio, Guardiola-Villora Arianna, Ortuño-Sáez Gonzalo
Multidisciplinary Institute for Environmental Studies, University of Alicante, Ctra. San Vicente del Raspeig, s/n, 03080 Alicante, Spain.
Department of Applied Physics, University of Alicante, Ctra. San Vicente del Raspeig, s/n, 03080 Alicante, Spain.
Sensors (Basel). 2025 Feb 4;25(3):933. doi: 10.3390/s25030933.
Radon gas anomalies have been investigated as potential earthquake precursors for many years. In this work, we have studied the possible correlations between radon emissions and the seismic activity rate for a given region to test if the existing correlation may be later used to forecast the occurrence of earthquakes larger than a given magnitude. The Vrancea region (Romania) was chosen as a study area since it is being surveilled by a multidisciplinary real-time monitoring network, and at least seven earthquakes with magnitudes greater than 4.5 Mw have occurred in this area in the period from 2016 to 2020. Our research followed several steps: First, the recorded radon signals were preprocessed (detrended, deseasoned and smoothed). Then, the station's signals were correlated in order to check which stations are recording radon anomalies due to the same regional tectonic process. On the other hand, the seismic activity rate was computed using the earthquakes in the main catalogue of the region that are able to generate radon emissions and can be registered at several stations. The obtained results indicate a significant correlation between the seismic activity rate and the temporal series of radon anomalies. A temporal lag between the seismic activity rate and the radon anomalies was found, which can be related to the proximity to the epicentre of the main earthquake in each of the studied subperiods. Changes in the regional tectonic stress field could explain why the seismic activity rate and radon anomalies are correlated over time. Further research could focus on obtaining a function to forecast the seismic activity rate using the following as dependent variables: the radon anomalies recorded at several stations, the distance from the stations, and tectonic factors such as the fault system, azimuth, type of soil, etc.
多年来，氡气异常一直作为潜在的地震前兆进行研究。在这项工作中，我们研究了给定区域内氡排放与地震活动率之间的可能相关性，以检验现有的相关性是否可用于预测大于给定震级的地震的发生。选择罗马尼亚的弗勒恰地区作为研究区域，因为该地区受到多学科实时监测网络的监测，并且在2016年至2020年期间该地区至少发生了7次震级大于4.5Mw的地震。我们的研究遵循了几个步骤：首先，对记录的氡信号进行预处理（去趋势、去季节化和平滑）。然后，对各站点的信号进行相关性分析，以检查哪些站点记录的是由于相同区域构造过程导致的氡异常。另一方面，利用该地区主目录中能够产生氡排放并可在多个站点记录的地震来计算地震活动率。所得结果表明地震活动率与氡异常的时间序列之间存在显著相关性。发现地震活动率与氡异常之间存在时间滞后，这可能与每个研究子时段内主震震中距离有关。区域构造应力场的变化可以解释为什么地震活动率和氡异常随时间相关。进一步的研究可以集中在获得一个函数，该函数以多个站点记录的氡异常、站点距离以及断层系统、方位角、土壤类型等构造因素作为自变量来预测地震活动率。
