Figure 1. Maps of earthquake rate change following the Landers earthquake (a) and the Hector Mine earthquake (b). The quantity that is mapped is N in equation (1) that is calculated for nonoverlapping spatial windows with dimensions of 0.5 x 0.5 deg. The time windows are t_post = 10 days, t_pre = 100 days, and t_lt is between January 1985 and January 2002. The stars indicate the epicenters of the Landers and the Hector Mine earthquakes. Aftershock activities are examined in four regions that are indicated by solid rectangles and are labeled as North1, North2, LVC, and South.