Spatial and temporal seismic imaging of fluid migration through the crust in the W-Bohemia/Vogtland earthquake swarm area

西波希米亚/沃格特兰地区的特点是空间集群群地震活动，典型的震源深度为6-12公里。脱气的上地幔衍生流体，与地震活动性，以及时间变化的排放气体，同位素组成的量和成分，并在震源过程中观察。从震源研究和事件间关系中发现了流体控制地震触发的证据。上地壳和壳幔过渡带都存在流体储集层，但它们的直接观测仍然缺失。震中和气泉在空间上是分离的，流体到地表的路径仍然没有得到解决，它们与地壳地震结构的关系也没有得到解决。这些特征使埃格裂谷/沃格特兰地区成为科学钻探的主要地点。在该项目中，将通过各种方法实现地壳地震结构和流体动力学的空间和时间成像。我们将测试假设存在的流体储层，并估计其空间范围使用地震速度和衰减层析成像以及尾波研究。我们将测量应力和流体动力学的时间演化，提供有关群震周期中上地壳变化的信息。该项目提供的3D和4D地震学模型将限制在埃格裂谷系统中最佳ICDP钻井位置的决策。

The W-Bohemia/Vogtland region is characterized by spatially clustered swarm earthquake activity with a typical source depth of 6-12 km. Degassing of upper mantle derived fluids, correlating with seismicity, is observed as well as temporal variations in the amount and composition of the emitted gas, isotope composition, and in earthquake source processes. Evidence for fluid-controlled earthquake triggering was found from earthquake source studies and inter-event relationships. Fluid reservoirs have been proposed for the upper crust as well as for the crust-mantle transition zone, but their direct observation is still missing. Epicentres and gas springs are spatially separated and the pathways of fluids to the surface remain unresolved as are their relations to the crustal seismic structure. These features make the Eger Rift/Vogtland area a prime site for scientific drilling. In this project spatial and temporal imaging of crustal seismic structures and fluid dynamics will be achieved by various approaches. We will test the hypothetical existence of a fluid reservoir and estimate its spatial extent using seismic velocity and attenuation tomography as well as coda studies. We will measure the temporal evolution of stress and fluid dynamics giving information about changes in the upper crust during a swarm earthquake cycle. The 3D and 4D seismological models delivered by this project will constrain the decision for an optimal ICDP drilling location in the Eger Rift system.