A real-time earthquake detector with prefiltering by wavelets

Abstract With the recent development and the growth of personal computers technology, we decided to implement a new earthquake detector. This detector, WDetect, can register in continuous mode all signals received from all our stations of the Local Seismic Network in the province of Alicante in the South-East of Spain. Simultaneously, our program can detect and store seismic events using the classical algorithm based on short- and long-term averages (STA and LTA, respectively). As a new improvement in the detection process, we have added signal prefiltering using the discrete wavelet transform, which increases the detection rate and reduces the false alarm rate, in contrast to other detectors like XDetect or XRTP. All this has been achieved without losing any meaningful event. These improvements were verified by an analysis performed during March 2001 on data from the Local Seismic Network in the province of Alicante, where WDetect has been running since the end of year 2000.