Toward Advanced Earthquake Cycle Simulation

Recent earthquake cycle simulation based on laboratory derived rate and state friction laws with super-parallel computers have successfully reproduced historical earthquake cycles. Earthquake cycle simulation is thus a powerful tool for providing information on the occurrence of the next Nankai megathrust earthquake, if simulation is combined with data assimilation for historical data and recently ongoing crustal activity data observed by networks extending from the land to the ocean floor. Present earthquake cycle simulation assumes simplifications in calculation, however, that differ from actual complex situations. Executing simulation relaxing these simplifications requires huge computational demands, and is difficult with present supercomputers. Looking toward advanced simulation of Nankai megathrust earthquake cycles with next-generation petaflop supercomputers, we present 1) an evaluation of effects of the actual medium in earthquake cycle simulation, 2) improved deformation data with GPS and InSAR and of inversion for estimating frictional parameters, and 3) the estimation of the occurrence of large inland earthquakes in southwest Japan and of Nankai megathrust earthquakes.