The region around the town Albstadt, SW Germany, was struck by four damaging earthquakes with magnitudes greater than 5 during the last century. These earthquakes occurred along the Albstadt Shear Zone (ASZ), which is characterized by more or less continuous microseismicity. As there are no visible surface ruptures that may be connected to the fault zone, we study its characteristics by its seismicity distribution and faulting pattern. We use the earthquake data of the state earthquake service of Baden-Württemberg from 2011 to 2018 and complement it with additional phase picks beginning in 2016 at the AlpArray and StressTransfer seismic networks in the vicinity of the ASZ. This extended data set is used to determine new minimum 1-D seismic v_p and v_s velocity models and corresponding station delay times for earthquake relocation. Fault plane solutions are determined for selected events, and the principal stress directions are derived.The minimum 1-D seismic velocity models have a simple and stable layering with increasing velocity with depth in the upper crust. The corresponding station delay times can be explained well by the lateral depth variation of the crystalline basement. The relocated events align about north–south with most of the seismic activity between the towns of Tübingen and Albstadt, east of the 9^∘ E meridian. The events can be separated into several subclusters that indicate a segmentation of the ASZ. The majority of the 25 determined fault plane solutions feature an NNE–SSW strike but NNW–SSE-striking fault planes are also observed. The main fault plane associated with the ASZ dips steeply, and the rake indicates mainly sinistral strike-slip, but we also find minor components of normal and reverse faulting. The determined direction of the maximum horizontal stress of 140–149^∘ is in good agreement with prior studies. Down to ca. 7–8 km depth $S_{{\text{H}}_{\text{max}}}$ is bigger than S_V; below this depth, S_V is the main stress component. The direction of $S_{{\text{H}}_{\text{max}}}$ indicates that the stress field in the area of the ASZ is mainly generated by the regional plate driving forces and the Alpine topography.

中文翻译：

---

阿尔卑斯山北部前陆阿尔布施塔特剪切带的地震活动性和地震构造

上个世纪，德国西南部阿尔布施塔特镇周围地区遭受了四次 5 级以上的破坏性地震。这些地震发生在阿尔布施塔特剪切带 (ASZ)，其特征是或多或少是连续的微地震。由于没有可见的可能与断层带相连的地表破裂，我们通过其地震活动分布和断层模式来研究其特征。我们使用了 2011 年至 2018 年巴登-符腾堡州地震服务部门的地震数据，并从 2016 年开始在 ASZ 附近的 AlpArray 和 StressTransfer 地震网络中补充了额外的相位选择。该扩展数据集用于确定新的最小一维地震v _p和v _s地震重定位的速度模型和相应的台站延迟时间。为选定的事件确定断层面解，并推导出主应力方向。最小一维地震速度模型具有简单而稳定的分层，随着上地壳深度的增加速度增加。相应的台站延迟时间可以用结晶基底的横向深度变化很好地解释。9 ^∘以东的图宾根和阿尔布施塔特镇之间的大部分地震活动与重新定位的事件大致呈南北对齐 E子午线。这些事件可以分为几个子集群，表明 ASZ 的分段。确定的 25 个断层平面解决方案中的大多数具有 NNE-SSW 走向，但也观察到了 NNW-SSE 走向的断层平面。与 ASZ 相关的主断层面急剧下降，前倾角主要显示左旋走滑，但我们也发现了正断层和逆断层的次要成分。的140-149的最大水平应力的所确定的方向^∘与先前的研究吻合。到约。7-8 公里深度${秒}_{{\text{H}}_{\text{最大限度}}}$大于S _V；在此深度以下，S _V是主要应力分量。的方向${秒}_{{\text{H}}_{\text{最大限度}}}$ 表明 ASZ 区域的应力场主要由区域板块驱动力和高山地形产生。