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

西波希米亚/沃格特兰流体流动动力学：成像和检测 (Bohemian FluID)

• 批准号: 419455546
• 负责人: Dr. Matthias Ohrnberger, since 10/2021
• 金额: --
• 依托单位: Abteilung Geophysik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/419455546?language=en
• 关键词: Dynamics; fluid; flow; Westbohemia; Vogtland

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.

在ICDP-Eger裂谷内，安装三个地震三维阵列将构成观察和调查西波希米亚/沃格特兰地区地球动力学过程的综合实验室的主要组成部分。在这项提议中，我们将永久安装一个3D阵列的表面部分，并为战略地点的地震观测提供额外的临时移动阵列。该项目将利用流体运动产生的周围地震噪声场，对西波希米亚/沃格特兰地区深层(几公里)流体通道的时间和空间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的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被认为是一种有用的工具，可以用来研究与浅层地下流体流动有关的噪声源的时空分布。我们将进一步开发MFP，以增强其成像和探测几公里深噪声源的能力。在该项目中，我们将使用永久地面阵列记录的地震学数据，安装在兰德伍斯特(沃格特兰)附近的ICDP钻探地点S1，使用临时移动阵列，并在可用时尽快安装井下设备。我们将重点放在位于11月11日科斯特尔焦点区域南部和北部的两个目标区域。在诺维科斯特勒南部，最近的地震学和大地电磁研究确定了一条与该地区发生的震群有直接联系的流体通道。诺维科斯特勒以北地区在过去几年中表现出浅层地震活动增加(不到8公里)，目前正在活跃。由于这两个区域的观测可能与地壳中的流体流动有关，我们将进一步开发和使用MFP来研究这些现象的时空行为。为此，我们将使用多阵列分析，加权输入数据以增强成像能力，并在处理中包括关于复杂速度模型的先验信息。同时，我们将使用多个阵列收集对目标区域深层流体路径的长期连续观测，这些观测将特别侧重于与震群发生有关的时间变化。总的来说，该提案旨在扩大可用于研究ICDP-Eger裂谷西波西米亚/沃格特兰地区深层流体流动和震群地震的地球动力学过程的方法学工具箱。