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

西波西米亚/沃格特兰地区以其频繁的板块内群活动而闻名，这些活动与上地幔向地壳的流体流动有关。外部强迫对该地区的地震活动起着重要作用。特别是最初的触发似乎受到地壳内部流体流动的高度影响。这些知识来源于地震矩张量解，它部分显示了Vogtland地区的高非剪切分量（non-DC）。然而，迄今为止，可用矩张量的数量有限以及确定的非直流分量的模糊性阻碍了对群体活动与流体流动之间关系的更详细分析。本项目旨在通过分析完整的地震矩张量，特别是它们的非直流电部分，有助于理解流体流动与地壳变形之间的联系。通过提高非直流电分量测定的准确度和精密度，我们能够更好地理解它们对地壳内地震构造过程的影响。我们将采取几种新方法来实现我们的目标。一种是结合旋转地面运动的测量。因此，我们测量了地震波场的六个分量，而不仅仅是三个分量，这在理论上已经证明了地震矩张量的波形反演是有价值的。另一个有希望的方法是实现非对称矩张量理论。它可以通过包括破裂期间的物质旋转来更好地解释变形，这将更好地约束该地区的构造。此外，我们还研究了三维结构模型的好处，以及各向异性对地震矩张量非直流部分的可分辨性的可能影响。

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.