seismic network when compared to an acausal network was attributed to the causal con- nections between events. Our results show that features of random networks are universal with the shuffled catalogs of both the regions showing identical network properties. The network from the actual catalog on the other hand shows some region specific features along with exhibiting typical causal attributes. The estimates of rupture length which arise as natural outcomes of the network construction are in good agreement with values estimated by other methods. The anamolies that are shown by the recurrent time distributions in the case of Japan when compared to expectations for a causal network could be a result of the heterogenous nature of seismicity in the region. Japan experiences a high level of seismicity due to its position at the cusp of the Pacific-Philippine-Eurasian triple plate junction. It has a predominantly compressional tectonic regime as compared to Western United States which is dominantly extensional [16]. We expect this aspect, along with the fact that dif- ferent recurrence intervals exist in Japan for earthquakes in subduction zones as compared to areas along crustal faults, to influence the recurrent time distributions which is shown in our results here. However analysis of catalogs for other such regions would have to be done in order to confirm this stand. 

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