[SSS04-P07] Direct and precise geodetic measurement across the Japan Trench after the 2011 Tohoku-oki earthquake
Keywords:2011 Tohoku-oki earthquake, Tohoku Earthquake, seafloor geodesy, acoustic ranging
In September 2015, we installed five instruments at the same, the region of large coseismic slip (e.g., Iinuma et al., 2012, JGR) and recovered in September 2016 (~360-days observation). The result shows no significant movement across the trench axis like as in the previous surveys. This result shows fully locked state and may clarify the absence of postseismic slip in the shallower part in this area and at least 2013-2016.
In March 2017, we plan to install five instruments across the Japan Trench off-Fukushima, where instead large postseismic slip (e.g., Sun and Wang, 2015, JGR; Iinuma et al., 2016, Nature Comm.). This auxiliary observation may reveal spatial variation of convergence rate along the trench axis.
Acknowledgement: This observation is supported by JSPS KAKENHI (26000002). The installation and recovery of the instruments were carried out during the KAIREI (KR15-15) and SHINSEIMARU (KS-16-14) cruises.