The Great East Japan Earthquake and Tsunami (GEJET) disaster is the deadliest disaster after the Second World War in Japan. The earthquake happened at 2:46 pm, 11st of March in 2011. The total casualty number is 19,846 based on the EM-DAT. The max. tsunami height is 40m at Sanriku ria coast. The first wave arrival is approx. 30 min. after the earthquake.
The Sanriku areas have a special geographical condition mentioned as a Sanriku ria coast. The coast has mountains close to the sea, so residential areas are limited only in the distributed narrow and lower zones near to the sea and the areas become very vulnerable against the tsunamis. The bays in the coast are small and the sea inside the bays is very deep. This makes tsunami faster and higher, this is why the Sanriku ria coast makes the highest tsunami risk area in the world.
Because of these characteristics, the communities in Sanriku ria coast, mainly in Iwate prefecture historically has been severely affected by tsunami disasters such as Meiji Sanriku Tsunami (Meiji (1896)), Sowa Sanriku Tsunami (Sowa (1933)), and Chilean Earthquake Tsunami (Chilean (1960)) disasters compared to the flat coast mainly in Miyagi prefecture and other areas in Japan.
I will explain a little bit about the Meiji (1896). This disaster is so-called a surprise attack, tsunami disaster happened at approx. 7:30 pm, 15th of June in 1896 mainly in the Sanriku ria coast. The dead and missing number has reported over 22,000. The earthquake is not so strong (Japanese earthquake scale indicates Shindo 1-2), however, the tsunami is very strong and high (max. height is 38.2m at Ayasato area (present Ofunato city)) compared to the earthquake movement scale. This makes severe impacts.We call this huge tsunami caused by a weak earthquake, Tsunami Earthquake. The first wave arrival is approx. 35m after the earthquake. The Meiji (1896) has been the worst tsunami disaster ever in Japan.
In 1611, the larger tsunami (Keicho Sanriku Tsunami*) than Meiji hit the Sanriku area. That could be also “tsunami earthquake”. After that, every 40 years, the people in the area tended to have a big tsunami. Even though they had such experiences, they did not have good tsunami disaster countermeasures and also the tsunami was “tsunami earthquake”. In addition, they had some ancient traditions like a tsunami is a punishment from the Gods and Buddha. These are the main causes to make the Meiji worse.
* Keicho Sanriku Tsunami
The Kyodo news company has obtained the pictures on the Meiji(1896)