Istituto Nazionale di Geofisica e Vulcanologia, Piazza Roma, 2 - 95123 Catania, Italy.
J Environ Radioact. 2011 Sep;102(9):863-70. doi: 10.1016/j.jenvrad.2011.05.002. Epub 2011 Jun 25.
This study concerns measurements of radon and thoron emissions from soil carried out in 2004 on the eastern flank of Mt. Etna, in a zone characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds for both parameters and producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. The seismic activity occurring in and around the study area during 2004 was analyzed, producing maps of hypocentral depth and released seismic energy. Both radon and thoron anomalies were located in areas affected by relatively deep (5-10 km depth) seismic activity, while less evident correlation was found between soil gas anomalies and the released seismic energy. This study confirms that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover or faults that are not clearly visible at the surface. The correlation between soil gas data and earthquakes depth and intensity can give some hints on the source of gas and/or on fault dynamics.
本研究关注的是 2004 年在埃特纳山东侧进行的土壤中氡和钍射气排放测量，该地区存在大量的发震和非发震断层。对地球化学数据的统计处理允许识别这两个参数的异常阈值，并生成分布图，突出显示土壤气体异常与构造线性之间存在显著的空间相关性。对研究区域内及周围 2004 年发生的地震活动进行了分析，生成了震源深度和释放地震能量的地图。氡和钍射气异常都位于受相对深（5-10 公里深度）地震活动影响的区域，而在土壤气体异常与释放的地震能量之间发现的相关性则不那么明显。本研究证实，绘制土壤气体中氡和钍射气的分布可以揭示被最近土壤覆盖物埋藏的隐伏断层或在地表上无法明显看到的断层。土壤气体数据与地震深度和强度之间的相关性可以提供有关气体来源和/或断层动力学的一些线索。
