Detection of Weak Seismic Signals in Noisy Environments from Unfiltered, Continuous Passive Seismic Recordings

摘要

Robust event detection of low signal-to-noise ratio (SNR) events, such as those characterized as induced or triggered seismicity, remains a challenge. The reason is the relatively small magnitude of the events (usually less than 2 or 3 on the Richter scale) and the fact that regional permanent seismic networks can only record the strongest events of a microseismic sequence. Monitoring using temporarily installed short-period arrays can fill the gap of missed seismicity, but the challenge of detecting weak events in long continuous records is still present. Further, for low SNR recordings, commonly applied detection algorithms generally require prefiltering of the data based on a priori knowledge of the background noise. Such knowledge is often not available.