Seismic tomography reveals a mid-crustal intrusive body, fluid pathways and their relation to the earthquake swarms in West Bohemia/Vogtland
Seismic tomography reveals a mid-crustal intrusive body, fluid pathways and their relation to the earthquake swarms in West Bohemia/Vogtland
复制标题
DOI：
10.1093/gji/ggv338
复制
发表时间：
2015-11
影响因子：
2.8
通讯作者：
S. Mousavi;K. Bauer;M. Korn;B. Hejrani
中科院分区：
文献类型：
--
作者：
S. Mousavi;K. Bauer;M. Korn;B. Hejrani
在捷克 - 德国边境地区的西波希米亚/沃格特兰地区的区域以地震群，二氧化碳散发和莫弗特领域的重复而闻名。与以前的研究相比，地震活动的更广泛的区域群体周围和下方可以在最高的地壳中揭示，这是Cheb Basin和Bublák/HartoušovMofette田地的首次成像Cheb盆地的异常并未继续进入EGER裂谷，表明盆地在裂谷系统中的特殊作用。地震焦点区域到Bublák/Hartoušovmofette田地，作为新特征，高VP的中心体和增加的VP/VS均在地震群的下方和北部。在裂谷系统的形成期间，我们推测出进度的流体流入焦点和地震的范围。冷却不是完全完成的。
S U M M A R Y The region of West Bohemia/Vogtland in the Czech–German border area is well known for the repeated occurrence of earthquake swarms, CO2 emanations and mofette fields. We present a local earthquake tomography study undertaken to image the Vp and Vp/Vs structure in the broader area of earthquake swarm activity. In comparison with previous investigations, more details of the near-surface geology, potential fluid pathways and features around and below the swarm focal zone could be revealed. In the uppermost crust, for the first time the Cheb basin and the Bublák/Hartoušov mofette fields were imaged as distinct anomalies of Vp and Vp/Vs. The well-pronounced low-Vp anomaly of the Cheb basin is not continuing into the Eger rift indicating a particular role of the basin within the rift system. A steep channel of increased Vp/Vs is interpreted as the pathway for fluids ascending from the earthquake swarm focal zone up to the Bublák/Hartoušov mofette fields. As a new feature, a mid-crustal body of high Vp and increased Vp/Vs is revealed just below and north of the earthquake swarm focal zone. It may represent a solidified intrusive body which emplaced prior or during the formation of the rift system. We speculate that enhanced fluid flow into the focal zone and triggering of earthquakes could be driven by the presence of the intrusive body if cooling is not fully completed. We consider the assumed intrusive structure as a heterogeneity leading to higher stress particularly at the junction of the rift system with the basin and prominent fault structures. This may additionally contribute to the triggering of earthquakes.