Spatiotemporal characterization of interswarm period seismicity in the focal area Nový Kostel (West Bohemia/Vogtland) by a short‐term microseismic study

• Published in: Geophysical journal international Vol. 179; no. 2; pp. 1071 - 1079
• Main Authors: Häge, Martin, Joswig, Manfred
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-11-2009
• Subjects: Neotectonics; Seismicity and tectonics; Statistical seismology
• ISSN: 0956-540X; 1365-246X
• DOI: 10.1111/j.1365-246X.2009.04320.x

SUMMARY
The West Bohemia/Vogtland region is one of the seismically most interesting areas in Europe because of its swarm‐like occurrence of seismicity. The installation of the local West Bohemian seismological network (WEBNET) has made the recording of small magnitude seismicity (detection threshold ML≈−0.5) possible. We investigated if microseismicity exists below the detection threshold of WEBNET. A microseismic field campaign was carried out in the focal area Nový Kostel. The measurement was performed with three small arrays lasting for 6 d in a seismically quiet, interswarm period. We were able to detect and locate 13 microearthquakes in the magnitude range −1.5 ≤ML≤−0.1 and achieved a detection threshold about one magnitude lower than the local network. A relative location suggests that the recorded seismicity is rather related to a specific fault segment than randomly distributed. The determined fault zone is aligned NW–SW and confirms the viability of mapping active faults with short‐term measurements. The results demonstrate that a linear extrapolation of the b‐value, determined by the network bulletin, down to ML=−0.5 fits well with the amount of our recorded events.