Non-Double-Couple components in moment tensors of various types of seismicity and their relation to anisotropy and fluid flow

关于地震矩张量中非双偶(NDC)分量的存在、起源和物理解释的讨论是一个长期和持续的争论，其相关性越来越大。由于最近在数据采集技术以及改进的反演算法方面取得的进展，现在有可能以前所未有的精度确定震源参数，彻底研究NDC分量的性质是一个现实的研究目标。在这里，我们建议系统地分析最近获得的关于NDC内容的不同类型地震的最新地震记录及其与地震各向异性和流体流动的关系。我们的研究重点是新发展的矩张量反演算法在以下方面的应用：1.1999年Mw=7.4和Mw=7.1的土耳其伊兹米特和杜兹塞地震后的余震活动；2.监测到的与火山有关的地震活动。Kolumbo，希腊，3.德国东南部KTB深井注入流体诱发的地震活动4.实验室岩石变形实验中观察到的声发射(微震)。通过这里提出的研究方案，我们试图论证NDC断层在四种不同类型地震中的作用。此外，我们希望弥合地球物理场研究(其中边界条件是固定的，但不是精确知道的)和实验室实验(其中边界条件是明确定义的)之间的差距。

The discussion on the existence, origin and physical interpretation of Non-Double-Couple (NDC) components in the seismic moment tensor of earthquakes is a long-standing and ongoing debate with increasing relevance. Due to recent progress achieved in data-acquisition technology as well as by improved inversion algorithms it is now possible to determine earthquake-source parameters with unprecedented precision and a thorough study of the nature of NDC components is a realistic research target. Here, we propose to systematically analyse recently acquired state of the art seismic recordings of different types of earthquakes with regard to NDC contents and their relation to seismic anisotropy and fluid flow. Our study focuses on the application of newly developed moment tensor inversion algorithms to 1. Aftershock activity following the 1999 Mw=7.4 and Mw=7.1 Izmit and Düzce, Turkey, earthquakes, 2. Volcano-related seismicity monitored at the submarine Mt. Kolumbo, Greece, 3. Fluid-injection induced seismicity at the KTB deep borehole, SE Germany and 4. Acoustic Emissions (microearthquakes) observed during rock-deformation experiments in the laboratory. With the here proposed research programme we attempt to argue on the role of NDC faulting in the four different types of earthquakes. Furthermore, we wish to bridge the gap between geophysical field studies (where boundary conditions are fixed but not known precisely) and laboratory experiments (where boundary conditions are well defined).