Modeling the development of a complex fault configuration in the source region of two destructive intraplate earthquakes in the mid-Niigata region

► We investigate the cause of two destructive earthquakes in the mid-Niigata region. ► We model the development of a complex fault configuration. ► The buried rift and weak zones in the basement are considered. ► Fault zones develop in the parts of the basement with a small frictional coefficient. ► Fault zones of the 2004 and 2007 earthquakes are reproduced in the present model.