Microseismic feasibility study: detection of small magnitude events (Ml<0.0) for mapping active faults in the Betic Cordillera (Spain)

摘要

We present the results of the first application of the newly developed concept «Nanoseismic Monitoring» on active
faults in the region close to Murcia, Spain. The aim of this microseismic feasibility study is to test if it is possible
to record small magnitude events (ML<0.0) within a short period of time with surface installations and to investigate
if these events are related to the regional catalog in terms of amount of events. The seismic monitoring
was performed with one small array called the Seismic Navigating System. It consists of one central three component
and three one component seismometers arranged tripartitely around the central station. In the measurement
period of two nights at two different sites we were able to detect 19 microearthquakes down to ML = -2.6. The results
correlate well with the frequency-magnitude distribution of the regional bulletin. This in turn will allow for
estimation of monitoring rates before actual field measurements just from bulletin data. Given an activity rate of
5 to 10 events per night one may map active fault zones within just a few weeks of field campaign.