The network approach plays a distinguished role in contemporary science of complex systems/phenomena. Such an approach has been introduced into seismology in a recent work [S. Abe, N. Suzuki, Europhys. Lett. <Emphasis Type="Bold">65, 581 (2004)]. Here, we discuss the dynamical property of the earthquake network...</emphasis>

The seismic data taken in California is mapped to a growing directed network. Then, statistics of period in the network, which implies that after how many earthquakes an event returns to the initial location, is studied. It is found that the period distribution obeys a power law, showing the...