A temporary network for seismological monitoring in West-Saxony: First results

Since December 1997 a network of 10 autanomously recording digital seismic stations operates in W-Saxony to monitor microseismic activity generated by tectonic movements in the Gera-Jachymov fault zone and induced by the floo ding of the uranium mining area near Aue. Further goals to be followed with these data are the in situ verification of engineering seismological param eters and the study of the transmission properties of seismic waves across the Gera-Jachymov fault zone to improve seismic risk evaluation. So far 19 tectonic and more than 50 induced events have been located and so urce parameters have been determined Event clusters near Zwickau and within the Arte mining nl ea could be spatially resolved with a master event tech nique. The cluster Hear Zwickau occured on a common fault plane striking pa rallel to the Gera-Jachymov fault zone and dipping at an angle of about 60 degrees towards ENE. The induced events near Arte occured within a volume o f approximately 5 km(3). The majority of these events were located in the g ranite body underneath the mining area. Fault plane solutions show a variet y of focal mechanisms with no clear relation to the regional stress field.