From what I'm reading, scientists and observers are classifying the recent event as "rare tidal waves" and the tsunami warning is lifted, so that would imply it doesn't happen too often, and hopefully won't happen often in the future. I hope for the sake of those in the dangerous areas, that the event is done and the danger is over for now.
Natural disasters in Japan: the danger is over for now, but the reality is that it is just a matter of time before disaster strikes again. That is bound to happen when you build a country on top of one of the world's biggest fault lines. They aren't very smart in that regard.
Japan is a special place. Japan is located right on the edge of a tectonic plate, and so, earthquakes will keep happening along with the Global Warming situation. I don't know how much of an effect Global Warming will have on this, but it might. As we all know by now, Global Warming is basically just heat increasing around the world. This means that atoms in different items, objects, or maybe the earths crust, will increase speed and movement. The hotter the object/item, the more it will move. This meaning that it's possible for the crust on earth will have more movement. That also means that Japan will have more earthquakes, causing more tsunamis, causing more destruction. Over time this will only get worse and worse. And since all of Japan is surrounded by water, it is going to take less time for the water level to be covering Japan's surface. Also underwater earthquakes and erosion caused by the water and moving tectonic plates will affect Japan at one point or another. I hope this response will help any people going by this opinion. And yes, it is possible that Japan is safe for a month or so, but over time this stuff will happen. In the next 100 years, it's possible that Japan will be completely uninhabitable.
No, the danger is not over for now because something could happen at any minute. There is no telling what comes next when dealing with natural disasters. They can strike whenever, wherever, regardless of what people do to stop them. We cannot sit back and assume the danger has passed.
Japan is an island that is very well developed. There are a lot of risks for natural disasters in Japan, including earthquakes and tsunamis. The risk can never be fully mitigated. Man cannot control nature. There are only so many things than man can do to protect himself, and the rest is up to God.