P-Time delay measurement of a doublet of microearthquakes

The measurement of temporal changes in crustal properties is important for earthquake prediction studies. This note shows that P-time delays of doublets of earthquakes recorded by standard seismic networks can be timed by crosscorrelation with a precision of a few milliseconds. Such precision is at least 50 times better than that of usual analysis of natural earthquakes and compares with that achieved with artificial sources experiments.