Automatic detection of microearthquakes in borehole records:
For the first time, an automatic detection workflow was successfully implemented to seismological data recorded in deep boreholes situated in the Koyna-Warna region. This workflow allowed identification of about twice as many events as compared to the time-consuming manual data processing. Also, a two-stage grid-search algorithm provided additionally better constraints on the absolute event locations. Further, a relative location process of these events using a waveform similarity approach was performed. These new events provided a tighter clustering than was obtained earlier. The seismicity trend correlates well with the anomalies obtained from airborne lidar studies. It is believed that the improvements achieved in detection and locations of microearthquakes using the borehole seismograms will provide better understanding of the RTS of the Koyna-Warna region (Shashidhar et al., 2020).