Fig. 12

Temporal evolution of slow slip in sub-regions (0.5° × 0.7°) of the plate interface along the Japan trench (after Uchida and Matsuzawa (2013)). a–c The period before the 2011 Tohoku-oki earthquake. d–f The year that includes the Tohoku-oki earthquake. The regions shown in g are categorized into areas with coseismic slip from the 2011 event with no afterslip (regions 6, 8, 9, 10, 11, and 12, in red); in the vicinity of the coseismic slip area and showing large, almost immediate slip after the Tohoku-oki earthquake (regions 4, 5, 7, 13, and 17, in blue); and areas distant from the coseismic slip showing small or delayed afterslip (regions 1, 2, 3, 14, 15, and 16). Panels a–f correspond to these categories. In g, contours show the coseismic slip distribution of the Tohoku-oki earthquake (Iinuma et al. 2012), stars show the epicenters of the 2011 Tohoku-oki earthquake and its two largest interplate aftershocks, and the thick black line shows the northeastern limit of the Philippine Sea plate in the Kanto region (Uchida et al. 2009a). Dashed ellipsoids show slip rate increases before the Tohoku-oki earthquake