Rapid mantle flow with power-law creep explains deformation after the 2011 Tohoku mega-quake

• DOI: 10.1038/s41467-019-08984-7
• Publication Date: 2019-03-26T11:03:26Z
• Authors: Ryoichiro Agata; Sylvain D. Barbot; Kohei Fujita; Mamoru Hyodo; Takeshi Iinuma; Ryoko Nakata; Tsuyoshi Ichimura; Takane Hori
• Keywords: Asthenosphere; Seafloor Spreading

Abstract The deformation transient following large subduction zone earthquakes is thought to originate from the interaction of viscoelastic flow in asthenospheric mantle and slip on megathrust that are both accelerated by sudden coseismic stress change. Here, we show combining insight laboratory solid-state creep friction experiments can successfully explain spatial distribution surface first few years after 2011 M w 9.0 Tohoku-Oki earthquake. reduction effective viscosity resulting dislocation asthenosphere explains peculiar retrograde displacement revealed seafloor geodesy, while acceleration accounts for displacements land offshore outside rupture area. Our results suggest a rapid takes place with temporarily decreased response stress, presumably due activation power-law during post-earthquake period.