Senior lecturer in oceanography at the University of Southampton Simon Boxall tells Paste BN that today's earthquake is "in the same location" as the 2011 earthquake that killed more than 19,700 people and sparked a disaster at the Fukushima nuclear plant.
Speaking to presenter Jayne Secker, Boxall says that in the coming minutes and hours we'll find out just how damaging today's earthquake is.
But he adds that "not all quakes create tsunamis".
Watch the interview below...