Co‐seismic slip, post‐seismic slip, and largest aftershock associated with the 1994 Sanriku‐haruka‐oki, Japan, earthquake

We analyzed continuous GPS data to investigate the spatio‐temporal distribution of co‐seismic slip, post‐seismic slip, and largest aftershock associated with the 1994 Sanriku‐haruka‐oki, Japan, earthquake (Mw = 7.7). To get better resolution for co‐seismic and post‐seismic slip distribution, we imposed a weak constraint as a priori information of the co‐seismic slip determined by seismic wave analyses. We found that the post‐seismic slip during 100 days following the main‐shock amount to as much moment release as the main‐shock, and that the sites of co‐seismic slip and post‐seismic slip are partitioning on a plate boundary region in complimentary fashion. The major post‐seismic slip was triggered by the mainshock in western side of the co‐seismic slip, and the extent of the post‐seismic slip is almost unchanged with time. It rapidly developed a shear stress concentration ahead of the slip area, and triggered the largest aftershock.