Stress State in the Largest Displacement Area of the 2011 Tohoku-Oki Earthquake

• DOI: 10.1126/science.1229379
• Publication Date: 2013-02-07T19:02:41Z
• Authors: Weiren Lin; Marianne Conin; J. Casey Moore; Frederick M. Chester; Yasuyuki Nakamura; James J. Mori; Louise Anderson; Emily E. Brodsky; Nobuhisa Eguchi; ; Becky Cook; Tamara Jeppson; Monica Wolfson-Sc...; Yoshinori Sanada; Saneatsu Saito; Yukari Kido; Takehiro Hirose; Jan H. Behrmann; Matt Ikari; Kohtaro Ujiie; Christie Rowe; James Kirkpatrick; Santanu Bose; Christine Regalla; Francesca Remitti; Virginia Toy; Patrick Fulton; Toshiaki Mishima; Tao Yang; Tianhaozhe Sun; Tsuyoshi Ishikawa; James Sample; Ken Takai; Jun Kameda; Sean Toczko; Lena Maeda; Shuichi Kodaira; Ryota Hino; Demian Saffer
• Keywords: [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics; 550; borehole; coseismic process; earthquake magnitude; fault displacement; in situ stress; integrated approach; Ocean Drilling Program; seismic moment; Tohoku earthquake 2011; 13. Climate action; [SDU.STU.TE] Sciences of the Universe [physics]/Earth Sciences/Tectonics; Oceanography and Atmospheric Sciences and Meteorology; 551; 01 natural sciences; 0105 earth and related environmental sciences

Stressed Out

Large seismic events such as the 2011 magnitude 9.0 Tohoku-Oki earthquake can have profound effects not just on the severity of ground motion and tsunami generation, but also on the overall state of the crust in the surrounding regions.

Lin et al.

(p. 687 ) analyzed the stress 1 year after the Tohoku-Oki earthquake and compared it with the estimated stress state before the earthquake. In situ resistivity images were analyzed from three boreholes drilled into the crust across the plate interface where the earthquake occurred. Stress values indicate a nearly complete drop in stress following the earthquake such that the type of faulting above the plate boundary has changed substantially. These findings are consistent with observations that the sea floor moved nearly 50 meters during the earthquake.