Abstract: Locating the microseismic events is important in the safety assessment of mines and the reservoir impoundment and in the
quality control of the hydraulic fracturing in the exploitation of gas and oil. However, due to the close arrivals of the microseismic
clusters, it is a great challenge to accurately locate the microseismic clusters using the methods based on arrival times. Based on the
reverse-time migration method, we proposed an approach using the joint of the reversed P wave field and S wave field to locate the
microseismics. In this approach, we use the absolute records as the source functions in the reverse-time process and calculate the
reversed wave fields (both P and S waves). Then, we pick out the origin times and the source locations of the microseismic clusters on
the imaging condition of the focusing-to-scattering transformation of the wave front. We used synthetic data to test this approach, and
the results indicate that this approach can successfully retrieve all the sources of the clusters.

Key words: microseismics, seismic location, reverse-time method, real-time monitoring