Rheological structure of northeastern Japan lithosphere based on geophysical observations and rock mechanics

► Rheology profile across the NE Japan predicts low strength along the volcanic front. ► Geodetic strain and shallow seismicity are concentrated into the low strength zone. ► The presence of partial melt and shear zones reduces viscosity significantly. ► The strain localization along weak zones may cause post-seismic creep. ►Elastic loading by localized deformation along shear zones reactivates old faults.