Accurate P-wave arrival detection via MODWT

P-wave arrivals of many weak events cannot be precisely determined manually. We use maximal overlap discrete wavelet transform (MODWT) for manually determining clear P-wave arrivals of weak events. We introduce an automatic onset detection and picking algorithm that uses the multi resolution analysis (MRA) components of this MODWT. Parameter settings are not needed, as the algorithm will work on data generated by either short or very broad band seismometers. The application of the proposed algorithm on data of three stations extracted from the Egyptian National Seismic Network (ENSN) in Cairo region shows a maximum standard deviation of 0.17 seconds for the corresponding manual picks.