A deep outer-rise reverse-fault earthquake immediately triggered a shallow normal-fault earthquake: The 7 December 2012 off-Sanriku earthquake (M-W 7.3)

作者：Harada Tomoya^*; Murotani Satoko; Satake Kenji

来源：Geophysical Research Letters, 2013, 40(16): 4214-4219.

DOI：10.1002/grl.50808

• outer-rise earthquake
• teleseismic body-wave analysis
• finite-fault slip model
• static change in the Δ CFF
• earthquake triggering
• the 2011 Tohoku earthquake
• outer-rise earthquake
• teleseismic body-wave analysis
• finite-fault slip model
• static change in the Δ CFF
• earthquake triggering
• the 2011 Tohoku earthquake

Teleseismic body wave analysis revealed that the 7 December 2012 off-Sanriku earthquake (M-W 7.3) at the outer rise of Japan Trench consisted of two successive subevents. The first subevent with reverse-fault mechanism (Event 1, M-W 7.1) at 56 km depth was followed by, approximately 20 s later, the second subevent with normal-fault mechanism (Event 2, M-W 7.2) at 6 km depth. Finite-fault slip models show that the slip of Event 1 was concentrated around the initial rupture point with the maximum of 2.7 m and that Event 2 had two asperities with the maximum of 4.5 m at both sides of the initial rupture point. The static Coulomb Failure Function analyses suggested that Event 1 triggered Event 2 and that both subevents were promoted by the 2011 Tohoku earthquake (M-W 9.1).

• 出版日期2013-8-28