Fig. 3.

Comparison of schematic views of source processes and related seismic activities for the (a) 2011 Tohoku, (b) 1964 Alaska, and (c) 2004 Sumatra earthquakes. Epicenters are shown by red stars, areas of major seismic moment release by orange patches and possible tsunami-excitation areas by red patches. In (a), the thick dashed lines represent the segments similar to Fig. 1(a), slow earthquakes including the 1896 great tsunami earthquake close to the trench are shown by four green patches, recent large Miyagi-Oki earthquakes by two blue patches, and five moderate Fukushima-Oki earthquakes in 1938 by light blue circles with a region of large excitation of high-frequency waves (Honda et al., 2011) and many aftershocks in light yellow. In (b), the orange patch is called the Prince William Sound asperity (PWS), two blue circles near the Kodiak Island represent intraplate earthquakes in 1999 and 2001 with the Kodiak Island asperity (KI) in yellow, and a creeping segment between them is shown in green (Ratchkovski and Hansen, 2001; Freymueller et al., 2008). In (c), the areas of large slips are estimated by teleseismic body waves in orange (Ammon et al., 2005) and those estimated by tsunami waveforms in red (Tanioka et al., 2006) with the three along-strike segments proposed by Lay et al. (2005).