Similarity of Waveforms at Stations Moxa and Plauen for the 1985/86 Swarm

A peculiarity of the Vogtland/West Bohemia earthquake region is the appearance of earthquake swarms. The strongest swarms in this century occurred in 1908 and 1985/86. The swarm in 1985/86 is the first one, for which digital data (about 220 events, 400 waveforms, sampling rate 100 Hz) are available for stations Moxa (MOX) and Plauen (PLN). The waveforms of the swarms in the Vogtland show a high similarity. The similarity is quantified by cross-correlation applied to approximately 400 waveforms. The results are shown in the form of similarity matrices.Four types of events have been detected using the results of the cross-correlation between the S-waveforms recorded at station PLN. Type IV occurs predominantly at the end of the swarm. The waveforms of type IV are clearly different from the waveforms of the other types. The differences between the waveforms of the first three types are less pronounced. Especially the first three types occur alternately.