The nature of the Albstadt Shear Zone, Germany

&amp;lt;p&amp;gt;&amp;lt;span&amp;gt;The region around the town of Albstadt, SW Germany, is one of the most seismically active regions in Central Europe. In the last century alone three earthquakes with a magnitude greater than five happened and caused major damage. The ruptures occur along the Albstadt Shear Zone (ASZ), an approx. 20-30 km long, N-S striking fault with left-lateral strike slip. As there is no evidence for surface rupture the nature of the Albstadt Shear Zone can only be studied by its seismicity.&amp;lt;/span&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;span&amp;gt;To characterize the ASZ we &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;continuously&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; complement the earthquake catalog of the &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;State Earthquake Service&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; of Baden-W&amp;amp;#252;rttemberg with additional seismic phase onsets. For the latter we use the station network of AlpArray as well as &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;5 &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;additional, &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;in 2018/2019&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; installed seismic stations from the KArlsruhe BroadBand Array. &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;W&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;e invert&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;ed&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; for &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;a &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;new minimum 1D &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;seismic &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;velocity model&amp;lt;/span&amp;gt; &amp;lt;span&amp;gt;of the study region. &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;We use this seismic velocity model to relocalize the complemented catalog&amp;lt;/span&amp;gt; &amp;lt;span&amp;gt;and to calculate focal mechanisms&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;. &amp;lt;/span&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;span&amp;gt;The majority of the seismicity happens between the towns T&amp;amp;#252;bingen and Albstadt at around 9&amp;amp;#176;E in a depth range of &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;about 1.5 to 16 km &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;and aligns &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;n&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;orth-&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;s&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;outh&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;. &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;Additionally, we see &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;a &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;cluster&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;ing of events at the town&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;s&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; Hechingen and Albstadt.&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; The dominating focal mechanism is strike-slip, &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;but we also observe &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;minor components of &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;normal and reverse faulting.&amp;lt;br&amp;gt;&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;Our results image the ASZ by its mainly micro-seismic activity b&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;etween&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; 2011 &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;and&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; 2018 &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;confirming the N-S striking character, but also indicating a more complex fault system.&amp;lt;/span&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;lt;span&amp;gt;We thank the &amp;lt;/span&amp;gt;&amp;lt;span&amp;gt;State Earthquake Service&amp;lt;/span&amp;gt;&amp;lt;span&amp;gt; in Freiburg for using their data (Az. 4784//18_3303). &amp;lt;/span&amp;gt;&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt;