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Tsunami at Kamaishi port, Iwate Prefecture

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• published: 13 Mar 2012
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The 311 Tsunami at Kamaishi port in Iwate Prefecture, Japan. Notes: This video is somehow unique, since it shows the actual comings and goings of the tsunami and not just the arrival of the biggest wave. It starts a couple of minutes after the earthquake, probably somewhere around 2:50 and 2:55 pm and then goes on for at least one and a half hour, plus some footage of the night and the next day. You can see how the water level falls in the minutes after the earthquake, the sign of an approaching tsunami. Then around 18:00 the tsunami begins to flood the port. The most impressive footage occurs during the two minutes after 24:00, then the tsunami overcomes the seawalls and smashes with incredible force into the city. The building from which this video was shot can be seen on a NHK video which was shown often on TV: http://www.youtube.com/watch?v=wBt5VlZkdyY It's behind the road bridge, on the right side. The building with the pyramid shaped tower. The video was probably shot out of this tower. At the entrance of the bay, a large structure can be seen. That structure is the Kamaishi Breakwater. It was intended to save the town from tsunamis and took 30 years to build until being completed in 2009. In 2010 it got its own entry in the Guinness Book of World Records, for it was the deepest breakwater on the planet. At 18:00 the waves begin flowing over the breakwater and for the next ten minutes it disappears in foam. When it reappears at 34:00 it is torn apart - it took Mother Nature merely ten minutes to smash something which took humans 30 years to build. Still it probably wasn't completely useless. Kamaishi was inundated in water up to 38 feet / 11.5 metres high, but that was behind the breakwater. In front of the breakwater, the water reached up to 100 feet / 30.5 metres. Ryoishi, a little fishing village further north Kamaishi Bay, which was not protected by the breakwater, got destroyed by waves up to 64 feet / 19.5 metres high. So the breakwater probably absorbed some of the tsunami's energy and deflected some more to the north side of the bay, which effectively halved the tsunami's height in Kamaishi city. Unfortunately that doesn't help at all if you're confronted with a monster tsunami, which even with its height halved is still higher than your defenses. Video recorded by Kamaishi Port Office, Ministry of Land, Infrastructure, Transport and Tourism. Provided by EERI member Shunsuke Otani.