The Once in a Hundred Years Earthquake

The tsunami that followed the big earthquake in Chile was close to a non-event in Okinawa, which is good. The earthquake the day before made a much bigger impression. Like most of Japan, Okinawa experiences frequent tremors, but hardly anyone alive today can remember one as strong as the one that rocked Okinawa last weekend.

It was rated five on Japan's magnitude scale. This is not the Richter scale, but the one in common use in Japan.

Magnitude One is easily overlooked. Magnitude Two is noticeable to people who have nothing else going on around them to distract them. Magnitude Three rattles windows and doors as it gently rocks buildings. You might not notice it if you are walking outdoors or driving. Magnitude Four knows how to get attention, and beyond level four, matters begin to get serious.

During a Magnitude Five earthquake, it is difficult to stand up. Things will topple off shelves, window glass might break, weakly constructed concrete walls and the like are likely to topple, signs hung outside buildings are quite likely to break loose and crash onto the streets, and pavements might ripple and crack.

Okinawa's recent earthquake was the first Magnitude Five quake in a hundred years.

One of the victims was the castle that gave its name to my first novel, Katsuren. Parts of the remaining stone wall from the 12th century structure crumbled and fell apart. The good news is that, because Katsuren has been designated a world cultural heritage site by UNESCO, it will be rebuilt.