Constraints on Quaternary processes in the Eastern Alps from a new detailed image of seismicity

该项目的目的是通过对当地震源的多参数研究，估计东阿尔卑斯山和南阿尔卑斯山/迪纳里德斯之间过渡区的阿尔卑斯山地壳变形。在历史上和仪器测量的年代，该地区发生了大多数最大的阿尔卑斯山地震（震级M≥6）。这里打算的高分辨率地震滑动方向和滑动速率图将有助于更好地了解地壳如何对造山力作出反应。我们假设，有争议的阿尔卑斯山脉的可能驱动因素，即构造，气候和侵蚀，对地震活动模式有不同的印记，他们的详细分析将使我们能够破译不同的贡献。与大地测量学和古地震学的合作项目相结合，它还将对阿尔卑斯山古地震、历史地震和未来可能发生的大地震的位置及其复发间隔提供重要的限制，从这次地震研究中得到的变形分布将与全球定位系统和干涉合成孔径雷达的观测相结合，这将有助于解释地震与地震变形的作用。将地震活动性和大地测量学与从结构分析、古地震和侵蚀率中进行的运动学研究相比较，将有助于确定变形是否持续了较长的时间尺度，或者运动模式是否随时间而改变。这项研究依赖于该优先方案第一阶段（AlpArray，SWATH-D）期间记录的新的丰富的地震数据。我们还将受益于我们自己以前在第一阶段的工作，在第一阶段，我们已经开发了一个有效的事件检测工作流程，适用于Alpine网络的大数据量，并实现了能够分析小震级事件的矩张量反演（到目前为止Mw~3）。我们量化地壳形变的目标需要精确测量基于地震活动性的参数，它可以分为两个部分：一方面是精确的震源及其空间和时间模式，另一方面是震源参数（地震矩张量、标量地震矩、应力降和破裂方向性）的集合。第一组将提供活动断层及其分段的位置、几何形状、方向和结构不均匀性。第二组将贡献滑动方向和滑动速率的补充信息。两者都意味着应用强大的，完善的方法，但也有新的方法，更好地表征所观察到的地震活动（地震活动聚类工具采用图论;矩张量反演和破裂方向性相结合）。这两个数据包最终将合并，组成东阿尔卑斯山和南阿尔卑斯山/迪纳里德斯地震滑动分布图。

This project is aimed at estimating the deformation in the Alpine crust in the transition zone between the Eastern Alps and the Southern Alps/Dinarides from a multi-parameter study of local earthquake sources. This region hosted most of the largest Alpine earthquakes in historical and instrumental times (magnitude M≥6). The here intended high-resolution map of seismic slip direction and slip rate will help to better understand how the crust reacts to the mountain building forces. We assume that the controversely debated possible drivers of the Alpine orogeny, i.e. tectonics, climate and erosion, have different imprints on the seismicity patterns, and their detailed analysis will enable us to decipher the different contributions. In combination with cooperating projects from geodesy and paleo-seismology it will also provide important constraints on the locations of paleo-, historical, and possibly of future large earthquakes in the Alps and on their recurrence intervals.The distribution of deformation from this earthquake study will be combined with observations from GPS and InSar, which will allow to decipher the roles of seismic vs. aseismic deformation. Comparison of seismicity and geodesy with kinematic studies from structural analysis, paleo-earthquakes and erosion rates will help to determine if deformation has persisted for a longer time-scale or if motion patterns have changed over time. The study relies on the new rich seismological data recorded during the first phase of this Priority Programme (AlpArray, SWATH-D). We will also benefit from our own previous work within the first phase, where we have developed an efficient event detection work-flow suitable for application to the big data volume of the Alpine networks and an implementation of moment tensor inversion capable of analyzing small magnitude events (so far Mw~3).Our aim of quantifying the crustal deformation requires accurate measurements of seismicity- based parameters, which can be grouped in two parts: Precise hypocenters and their spatial and temporal patterns on the one hand and an assembly of source parameters (seismic moment tensors, scalar seismic moment, stress drop and rupture directivity) on the other hand. The first group will provide the locations, geometry, orientation and structural heterogeneity of active faults and their segmentation. The second group will contribute the complementary information of slip direction and slip rates. Both imply the application of robust, well-established methods, but also of novel approaches for a better characterization of the observed seismicity (seismicity clustering by tools adopted from Graph theory; combination of moment tensor inversion and rupture directivity). The two packages will be finally merged to compose a map of seismic slip distribution in the Eastern Alps and the Southern Alps/Dinarides.