Fig. 3.

(A) Attack fractions per cluster attributable to AQ and ISIS, 2001 to 2017. (B) First ISIS attack dates per cluster vs. distance from Iraq post-2014. A linear regression yields a spread of roughly 2,400 km/y with correlation $r=0.79$ and a significant $p$ value of 0.006. (C) Near-repeat patterns for AQ $\to$ AQ and ISIS $\to$ ISIS worldwide, 2014 to 2017. Each bar contains data binned over 2 weeks. Deviations from the REH are estimated using KLD. (C1) The distribution of AQ $\to$ AQ attacks separated by less than 20 km deviates from the REH over the first 4 weeks, indicating increased near-repeat likelihood. (C2) For ISIS $\to$ ISIS attacks the enhanced repeat likelihood is over the first 10 weeks. (C3 and C4) AQ $\to$ AQ and ISIS $\to$ ISIS attacks separated by more than 100 km follow the REH, suggesting negligible correlation between repeat events.