Gravitational body forces focus North American intraplate earthquakes

• DOI: 10.1038/ncomms14314
• Publication Date: 2017-02-17T11:45:04Z
• Authors: Will Levandowski; Mark Zellman; Rich Briggs
• Keywords: Science; Q; 01 natural sciences; Article; 0105 earth and related environmental sciences

Abstract Earthquakes far from tectonic plate boundaries generally exploit ancient faults, but not all intraplate faults are equally active. The North American Great Plains exemplify such earthquake localization, with both natural and induced seismicity clustered in discrete zones. Here we use seismic velocity, gravity topography to generate a 3D lithospheric density model of the region; subsequent finite-element modelling shows that focuses regions high-gravity-derived deviatoric stress. Furthermore, predicted principal stress directions align those observed independently moment tensors borehole breakouts. Body forces therefore appear control state thus location style earthquakes central United States no influence mantle convection or crustal weakness necessary. These results show mapping where gravitational body encourage is crucial understanding appraising hazard.