High-resolution 3D earthquake forecasting beneath the greater Tokyo area

Abstract

Abstract We propose an extended 3D space (longitude, latitude, and depth) epidemic-type aftershock sequence (ETAS) model for seismicity forecasts beneath the greater Tokyo area (the Kanto region), which also takes into account the effects induced by the M9 Tohoku-Oki earthquake of 2011. The model is characterized by a number of 3D location-dependent parameters, such as the background seismicity rates, and the productivity rate induced by the Tohoku earthquake. These allow production of high-resolution predictive mappings in zones where hypocenters are densely populated. The optimally inverted 3D spatial images of the characterizing parameters effectively discriminate seismicity features in the crust and near the plate boundaries. The success of the model is demonstrated using short-, intermediate- and long-term probability forecasts of intermediate and large earthquake occurrences beneath the Kanto region.

Keywords

• 3D Delaunay tessellation
• Hierarchical space–time ETAS model
• Induced seismicity
• Penalized log likelihood function
• Akaike‘s Bayesian Criterion
• M9 Tohoku-Oki Earthquake