Locating Scattered Energy in Vogtland's Earthquake Swarm Source Area through Double 3D-Array Beamforming and Inter-Event Coda Correlation Imaging (D3D)

我们的目标是从瞬时地震信号中检测和量化位于西波希米亚/沃格特兰地区震源区及其周围的地壳散射体的特征。散射强度的量化及其对不同角度的依赖提供了对散射体作为结构元素的性质的洞察，以及它们与假设的持续的深部流体流动的可能的物理关系。我们将利用在多个阵列上观察到的弱尾波相位所获得的信息。为了提高观测的高频含量，我们将在经典的地面阵列下安装一个深孔阵列，用于连续观测瞬变信号和环境振动波场。这种3D阵列装置(接收器阵列/RA)将与被称为震源阵列(SA)的相互作用的3D阵列记录几何结构结合使用，以一致地将弱散射能量定位在靠近震群产生的体积内。此外，我们还建议使用源到源尾波关联技术来生成源间格林函数数据库。该数据库将从最近几年的现有群体数据中得出，但随后通过对新部署的设施的观察进一步扩大。它将被用来得出震群区域源区的速度结构，并将不仅可以调查速度异常的空间特征，还可以调查速度异常的时间特征，作为震群触发的可能原因或深部流体路径的指示。

We aim to detect and quantify the characteristics of crustal scatterers located within and around the source area of the West Bohemian / Vogtland region from transient Earthquake signals. The quantification of scattering strength and its dependence on variable angles provides insight into the nature of scatterers as structural elements and their possible physical relation with the postulated ongoing deep fluid flow. We will exploit the information from the observation of weak coda phases at multiple arrays. In order to improve the high frequency content of the observations we will install a deep borehole array beneath a classical surface array for the continuous observation of transient signals as well as the ambient vibration wave field. This 3D-array installation (receiver array / RA) will be used in combination with the reciprocal 3D array recording geometry known as source array (SA) for consistently locating weak scattered energy close and within the volume of earthquake swarm generation. Furthermore we propose to use a source to source coda correlation technique to generate an inter-source Green’s function database. This database will be derived from existing swarm data in recent years but then further augmented by observations at the newly deployed installations. It will be used to derive the velocity structure in the source volume of the swarm region and will allow investigating not only the spatial but also the temporal character of velocity anomalies as possible cause for swarm triggering or indications for fluid pathways in depth.