Tidal Waves’ Wake of Death

Tidal waves, known often by the Japanese word tsunami, are most common in the Pacific Ocean and since 1946 have twice caused substantial death and destruction in Hawaii and once in California.

Such waves, which have crested as high as 210 feet, are usually caused by earthquakes at sea, such as the one that struck Flores island in the Indonesian Archipelago on Saturday, although occasionally the cause can be land-based earthquakes, landslides or volcanic eruptions.

Tsunamis can reach speeds of 600 m.p.h., and, while difficult to detect in the open sea where the crest is not dramatic, grow in height as they reach shore.

In the Krakatoa eruption near Indonesia in 1883, many of the 36,000 deaths were caused by tsunamis.