Anatomy of an earthquake

The facts and the results

The earthquake that struck the Tohoku region in Japan in March 2011 was one of the most powerful recorded since the start of the 20th century. Measured with a magnitude of 9, it triggered a tsunami that caused damage along a 600 km coast and partially or completely destroyed a large number of towns and harbours. The ability to anticipate the consequences of major earthquakes, which Japan and Turkey in particular are undoubtedly going to have to deal with in the coming years, is a critical issue in managing populations and infrastructures. In finding answers, the Tohoku earthquake acts as a reference point for the work towards an improved understanding of its “lifecycle”: The triggering of the fracture, the spread of the fault, propagation of seismic waves, surface consequences, etc.

The results

The simulations, impossible to carry out using workstations, were performed in 2012 and 2013 by the BRGM in collaboration with the University of Tokyo, using the Jade computer at GENCI, and made it possible to reproduce this mega-quake in its entirety. This stage requires refinements with the inclusion of temporal changes and spatial heterogeneities at every level, with the aim of building operational scenarios that can be used to support the development of public policy.

Details

110 000 core hours on Jade (Cines)

Principal Investigator: Hideo Aochi - BRGM and Université de Tokyo