2019 Volume 56 Issue 4 Pages 203-210
It is important to reveal fault structures and stress states in accretionary prisms for understanding the building and releasing of seismic energy as they control the generation of great earthquakes and tsunami. Here we show the evolution process of three-dimensional fault structures on sandbox simulations using a discrete element method (DEM). To realize the real-scale sandbox simulation, we developed state-of-the-art techniques in high performance parallel computing methods for the DEM, and then performed the largest DEM simulation in the world using up to 1.9 billion particles with similar grain size of real sand for identifying the three-dimensional fault structure. The DEM simulations reproduced the undulation of fault structures similar to those found commonly in nature. In addition, the characteristic grain motion was found near the frontal fault before beginning the uplift event of sand bed, which could be a precursor of tectonic events behind accretionary prism formation.