Unusually Deep Bonin Earthquake (M7.9) of May 30, 2015 Suggests that Stagnant Slab Transforms into Penetration Stage

Masayuki Obayashi1, Yoshio Fukao1 and Junko Yoshimitsu2, (1)JAMSTEC Japan Agency for Marine-Earth Science and Technology, Kanagawa, Japan, (2)JAMSTEC, Yokosuka, Japan