Dynamics of fluid flow in Westbohemia/ Vogtland: Imaging and Detection (Bohemian FluID)

在ICDP-Eger裂谷内，三个地震三维阵列的安装将构成综合实验室的主要组成部分，用于观察和研究西波西米亚/ Vogtland地区的地球动力学过程。在这个建议中，我们将永久安装一个三维阵列的表面部分，并在战略点提供额外的临时移动阵列用于地震观测。该项目将利用流体运动产生的环境地震噪声场，对西波西米亚/Vogtland地区深部（几公里）流体路径的时空演变进行地震调查和成像。我们将采用匹配场处理（MFP），这是一种通过比较合成地震波场和记录地震波场来成像和检测地下噪声源的处理方法。在以往的研究中，MFP已被确定为研究浅层地下流体流动相关噪声源时空分布的有用工具。我们将进一步发展MFP，以提高其成像和探测数公里深噪声源的能力。在该项目中，我们将使用安装在靠近landw<e:1> st （Vogtland）的ICDP钻井位置S1的永久地面阵列记录的地震数据，通过临时移动阵列记录的地震数据，以及一旦可用的井下设备记录的地震数据。我们的重点是位于Nový Kostel震源区南部和北部的两个目标区域。在Nový Kostel南部，最近的地震学和大地电磁研究确定了一条流体通道，并提出了与该地区发生的地震群直接相关的建议。Nový Kostel北部地区在过去几年中显示出浅层地震活动增加（小于8公里），目前很活跃。由于这两个区域的观测都可能与地壳中的流体流动有关，我们将进一步发展和使用MFP来研究这些现象的时空行为。为此，我们将采用多阵列分析、权重输入数据来增强成像能力，并在处理过程中包含有关复杂速度模型的先验信息。同时，我们将利用多个阵列收集目标区域深层流体路径的长期连续观测数据，并将重点研究与地震群发生相关的时间变化。总体而言，该提案旨在扩大可用的方法工具箱，以研究与ICDP-Eger裂谷中西波西米亚/ Vogtland地区深部流体流动和群震有关的地球动力学过程。

Within the ICDP-Eger Rift the installation of three seismic 3D arrays will form a major component of the comprehensive laboratory to observe and investigate the geodynamic processes in the region West Bohemia/ Vogtland. In this proposal, we will permanently install the surface part of one 3D array and provide an additional temporary mobile array for seismological observations at strategic points. The project will seismically investigate and image the temporal and spatial evolution of deep (several kilometres) fluid pathways in the region West Bohemia/Vogtland by using the ambient seismic noise field generated by fluid movements. We will employ matched field processing (MFP), a processing approach aiming at imaging and detecting noise sources in the subsurface by comparing synthetic and recorded seismic wavefields. In previous studies, MFP has been identified as a useful tool to investigate the temporal and spatial distribution of noise sources related to fluid flow in the shallow subsurface. We will further develop MFP to enhance its capabilities to image and detect several kilometres deep noise sources. In the project, we will use seismological data recorded by a permanent surface array to be installed at the ICDP drilling location S1 near Landwüst (Vogtland), by a temporary mobile array and by downhole installations as soon as they will be available. We focus on two target regions located South and North of the Nový Kostel focal zone. In the South of Nový Kostel, recent seismological and magnetotelluric studies identified a fluid channel for which a direct link to the earthquake swarms occurring in this region was proposed. The region North of Nový Kostel showed an increased shallow earthquake activity (less than 8 km) within the last few years and is currently active. As the observations in both regions are potentially linked to fluid flow in the crust, we will further develop and use MFP to investigate the spatio-temporal behaviour of these phenomena. For this purpose, we will employ multi-array analysis, weight input data to enhance imaging capabilities, and include a priori information concerning complex velocity models in the processing. In parallel, we will collect long-term continuous observations of deep seated fluid pathways in the target regions using multiple arrays which will be investigated with special emphasis on the temporal changes in relation to the occurrence of earthquake swarms. Overall the proposal aims to enlarge the methodological tool box available to investigate the geodynamic processes related to deep fluid flow and swarm earthquakes in the region West Bohemia/ Vogtland in the ICDP-Eger Rift.