Fig. 2.
From: Nearly complete stress drop in the 2011 Mw 9.0 off the Pacific coast of Tohoku Earthquake
(a) P (red square), B (green) and T (blue) axes of focal mechanisms and (b) best fit principal stress σ1 (red circle), σ2 (green triangle) and σ3 (blue square) projected on the lower focal hemisphere by equal area projection for earthquakes that occurred before the Tohoku earthquake in region A. (c) and (d) show those for events in region B. In (b) and (d), principal stresses falling within 68% and 95% confidence levels are shown by lighter colors. Focal mechanisms for the period of 1997–March 10 2011 are used for the inversions.