Hypocentre estimation of induced earthquakes in Groningen
Hypocentre estimation of induced earthquakes in Groningen
复制标题
DOI：
10.1093/gji/ggx020
复制
发表时间：
2017-04
影响因子：
2.8
通讯作者：
J. Spetzler;B. Dost
中科院分区：
文献类型：
--
作者：
J. Spetzler;B. Dost
自1986年以来，荷兰东北部格罗宁根省发生了因天然气生产而诱发的地震。在地震活动的最初几年，使用了一个稀疏的地震网络，距离格罗宁根的孕震区有很大的台站距离。诱发地震的位置受到台站数量少、分布广的限制。最近，监测站网络得到了显著扩展，格罗宁根诱发地震的定位已成为日常工作。除了事件的深度估计。在荷兰皇家气象研究所（KNMI）用于震源定位的震源方法中，诱发地震的深度默认设置为3 km，这是气藏的平均深度。或者，将用于震源定位的P波差分走时方法应用于来自扩展网络的记录数据。估计了2014年至2016年7月87次诱发地震的震中和深度。新估计的震中接近KNMI目前采用的方法所引发的地震位置。据观察，诱发地震大多发生在水库水位。在以岩盐为主的碳酸盐岩覆盖层中的脆性硬石膏层附近发现了几个相同量级的地震。
Induced earthquakes due to gas production have taken place in the province of Groningen in the northeast of The Netherlands since 1986. In the first years of seismicity, a sparse seismological network with large station distances from the seismogenic area in Groningen was used. The location of induced earthquakes was limited by the few and wide spread stations. Recently, the station network has been extended significantly and the location of induced earthquakes in Groningen has become routine work. Except for the depth estimation of the events. In the hypocentre method used for source location by the Royal Netherlands Meteorological Institute (KNMI), the depth of the induced earthquakes is by default set to 3 km which is the average depth of the gas-reservoir. Alternatively, a differential traveltime for P-waves approach for source location is applied on recorded data from the extended network. The epicentre and depth of 87 induced earthquakes from 2014 to July 2016 have been estimated. The newly estimated epicentres are close to the induced earthquake locations from the current method applied by the KNMI. It is observed that most induced earthquakes take place at reservoir level. Several events in the same magnitude order are found near a brittle anhydrite layer in the overburden of mainly rock salt evaporites.