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

我们的目标是从瞬态地震信号中探测和量化位于西波西米亚/沃格特兰地区震源区内及其周围的地壳散射体的特征。散射强度的量化及其对可变角度的依赖提供了对散射体作为结构元素的性质及其与假定的持续深部流体流动的可能物理关系的深入了解。我们将利用在多个阵列上观察到的弱尾相的信息。为了提高观测的高频含量，我们将在经典表面阵列下安装一个深钻孔阵列，用于瞬态信号和环境振动波场的连续观测。这种3D阵列装置（接收器阵列/ RA）将与互反3D阵列记录几何形状（称为源阵列（SA））结合使用，以始终定位地震群产生的附近和体积内的弱散射能量。此外，我们建议使用源到源尾数据相关技术来生成源间格林函数数据库。这个数据库将来自近年来现有的蝗群数据，然后通过对新部署的设施的观察进一步扩充。它将用于推导群区源体积中的速度结构，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，这可能是引发群的原因，或者是深度流体通道的指示。

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.