A short ferry ride from Setana lies Okushiri-toh (奥尻島 / literally ‘centre buttocks island’ – yes, as usual, your guess is as good as mine), which on the night of 12th July 1993 was witness to one of Japan’s worst natural disasters of recent times.
Following a 7.8-magnitude earthquake just off the coast, within three minutes the island was hit by the first wave of a tsunami, and just seven minutes after that by a second, even bigger wave. 233 people lost their lives – some as far afield as Aomori in northern Honshu and Russia on the other side of the Japan Sea – and among the dead were 4% of Okushiri’s population.
(There’s some news footage of the aftermath about a minute and a half into this video – which is in Japanese – and then at various points throughout.)
– Even if it were possible to speed up the transmission of tsunami warnings, depending on the location of an earthquake’s epicentre, the fact that some warnings will not arrive in time is unavoidable.
– If people who live in coastal areas feel the tremors from a large earthquake, they should evacuate to higher ground or the tops of tall buildings straight away, and without waiting for tsunami warnings.
– Depending on their location, tsunami can be higher than predicted, hit many times over, and subesequent waves from a tsunami are sometimes higher than the initial one.
The tragedy is that despite these lessons having supposedly been ‘learned’ after the Okushiri Earthquake, by the time of the Great East Japan Earthquake in 2011, the Japanese people, the authorities and the so-called ‘experts’ had for a long time been underestimating not just the probability of something similar happening elsewhere in the country, but perhaps more importantly, its scale.
For example, the largest wave from the tsunami caused by the Okushiri Earthquake in 1993 (or to be more specific, the highest point above sea level that was inundated by waves from the tsunami) was thirty metres, while the largest wave from the tsunami caused by the Great East Japan Earthquake in 2011 was forty metres.
In both cases, many people died because they either failed to evacuate to higher ground, because they evacuated by car and were caught in traffic jams, because the coming tsunami was estimated in official warnings as being no more than a few metres high, because in some areas, the tsunami arrived within just ten minutes of the earthquake, and because the initial waves from the tsunami were not necessarily its highest.
Much more so than western Hokkaido, the north-east coast of Honshu has a long history of off-shore earthquakes, including some within living memory. For example, the largest wave from the tsunami caused by the Shohwa-sanriku Earthquake (昭和三陸地震) in 1933 was twenty-eight metres high.
In the same way that residential areas are now in the process of being moved to higher ground in Tohoku, laws were introduced after the Sanriku quake in an effort to prevent people from building houses on low-lying ground that might be vulnerable to tsunami. Sadly, though, these laws were never properly enforced, and many of the same communities which had been destroyed in 1933 were destroyed all over again in 2011.
That evening the owner of the Tsuji Ryokan gave me a map of Esashi with all of the town’s restaurants and bars marked on it, and I followed a roundabout route through the deserted backstreets on the way to and from my evening meal at a local izakaya.