Seismotectonic investigation of the Alborz Mountains, Northern Iran, by means of an innovative algorithm for seismic moment tensor retrieval

在伊朗北部的阿尔博尔茨山脉，一个复杂但尚未被很好理解的走滑和逆冲断裂系统适应了NNE-SSW向的缩短作用。到目前为止，一个不均匀的、空间上不同的地震网络和缺乏适当的方法阻碍了在该地区进行详细的矩张量研究。地震矩张量提供了地震物理过程和震级的一般描述。因此，他们的知识是地震构造和地震危险性评估研究的基础。矩张量反演的可行性受到多种条件的制约，这限制了世界各地许多震源研究中可用观测的范围。为了克服这一问题，我们将开发一种及时的、概念上的创新算法来结合宽带台的波形数据，以及短周期台站和加速度计的初动体波极性以及可能的P波和S波的振幅比。我们将在阿尔博尔茨山脉恢复一个新的和有代表性的地震矩张量，并将它们用于地震构造解释。因此，我们的工作将有助于扩展阿拉伯-欧亚碰撞带这一关键地区的地震构造解释和地震危险性分析的结构和地貌数据库。除了区域地震构造方面的这些优势外，该项目开发的方法也可以应用于世界其他构造活动区。

A complex and not well understood system of strike-slip and thrust faults accommodates NNE-SSW oriented shortening in the Alborz Mountains of northern Iran. To date, a heterogeneous, spatially disparate seismic network and a lack of appropriate methods have prevented detailed moment tensor studies in this region. Seismic moment tensors provide a general description of the physical processes and the magnitude of earthquakes. Their knowledge is therefore fundamental for seismotectonic and seismic hazard assessment studies. The feasibility of moment tensor retrieval is controlled by several conditions, limiting the available observations in many earthquake source studies worldwide. To overcome this, we will develop a timely and conceptually innovative algorithm to combine waveform data of broadband stations, as well as first motion body-wave polarities and probably also amplitude ratios of P- and S-waves of short-period stations and accelerometers. We will retrieve a new and representative number of seismic moment tensors in the Alborz Mountains and use them for seismotectonic interpretation. Our work will thus help extend the structural and geomorphic data base for seismotectonic interpretation and seismic hazard analysis in this crucial area of the Arabia-Eurasia collision zone. Beyond these advantages concerning regional seismotectonic aspects, the methodology developed in this project can also be applied to other tectonically active regions worldwide.