>> reporter: this could happen in the next hour, hour and a half. just because we had the blip in hawaii doesn't mean there won't be significant ones. as we look back at history, the most powerful earthquake happened on chile, 9.5 magnitude in 1960, that generated a huge tsunami and killed thousands of people in japan. so we know that this is something that could potentially be happening. this is a map of some of the japanese meteor logical agencies here, and this shows you the degree of the threat. so think of it as yellow is lower, red highest. and to put it in perspective for you, tokyo's down here, okinawa's down here, we have fishing villages more than anything else in this area, there's still literally thousands of people who live in this area, it's the red highlighted spot where a major tsunami could still happen. and that's at 10 feet or more, potentially.