mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis mini-tsunamis earthquake with a magnitude of 6.9 struck northern Japan mini-tsunamis mini-tsunamis mini-tsunamis