▽関連リンク Nature Communications 6, Article number: 5934 doi:10.1038/ncomms6934 Received 05 May 2014 Accepted 21 November 2014 Published 06 January 2015 A very long-term transient event preceding the 2011 Tohoku earthquake www.nature.com/ncomms/2015/150106/ncomms6934/abs/ncomms6934.html