Non-double-couple moment tensor components and their relation to fluid flow in the West-Bohemia/Vogtland region

非双偶矩张量分量及其与西波希米亚/沃格特兰地区流体流动的关系

• 批准号: 457073417
• 负责人: Dr. Stefanie Donner
• 金额: --
• 依托单位: Forschergruppe Allgemeine Geophysik, FSP Seismologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/457073417?language=en
• 关键词: Non; double; couple; moment; tensor

The West Bohemia/Vogtland region is well known for its frequent intraplate swarm activity connected to fluid flow from the upper mantle into the crust. External forcing plays an important role for the seismic activity of the region. Especially the initial triggering seems to be highly influenced by the fluid flow within the crust. This knowledge is derived from seismic moment tensor solutions, which partly show high non-shear-components (non-DC) for the Vogtland region. However, the limited number of available moment tensors and the ambiguity of the determined non-DC components have so far hampered a more detailed analysis of the connection between swarm activity and fluid flow. This project aims to contribute to the understanding of the connection between fluid flow and crustal deformation by analysing full seismic moment tensors, especially their non-DC part. By improving the accuracy and precision of the determination of non-DC parts, we are able to better understand their implications for seismotectonic processes within the crust. We will take up several new approaches to reach our goals. One is to incorporate measurements of rotational ground motions. Thus, we measure six instead of only three components of the seismic wavefield which already proved to be valuable for waveform inversion for seismic moment tensors in theory. Another promising approach is to implement the theory of the asymmetric moment tensor. It enables to better account for deformation by including material rotations during the rupture which will give better constraints on the tectonics of the region. In addition, we examine the benefits of a 3D structural model and the possible influences of anisotropy to the resolvability of non-DC parts of the seismic moment tensor.

西波希米亚/沃格特兰地区以其频繁的板内震群活动而闻名，这些活动与从上地幔流入地壳的流体有关。外部强迫对该地区的地震活动起着重要作用。特别是初始触发似乎受到地壳内流体流动的高度影响。这方面的知识是来自地震矩张量的解决方案，其中部分显示高非剪切分量（非DC）的Vogtland地区。然而，有限数量的可用的时刻张量和确定的非直流分量的模糊性，到目前为止，阻碍了更详细的分析群活动和流体流动之间的联系。该项目旨在通过分析完整的地震矩张量，特别是其非直流部分，帮助理解流体流动与地壳变形之间的联系。通过提高非直流分量测定的准确度和精度，我们能够更好地理解它们对地壳内地震构造过程的影响。我们将采取几种新的方法来实现我们的目标。一个是将旋转地面运动的测量。因此，我们测量的地震波场的六个而不是只有三个分量，这已经被证明是有价值的波形反演地震矩张量在理论上。另一个有希望的方法是实现非对称矩张量理论。它能够更好地解释变形，包括在破裂过程中的材料旋转，这将给该地区的构造更好的约束。此外，我们研究的好处，一个三维结构模型和各向异性的地震矩张量的非DC部分的可分辨性的可能影响。