TsunamiIn 1854, a tsunami struck the coast of Japan. In the harbor of Simoda the water was agitated so that its depth varied between 8 and 40 feet. Twelve hours later this giant tidal wave reached the Pacific coast of the U.S. Notice of the earthquake waves was observedon newly installed self-registering tide gauges, a new technology at the time. The information derived from this event enabled Alexander D. Bache, Superintendent of the U.S. Coast and Geodetic Survey, to apply a newly derived law relating ocean depth to wave speed and provide the first relatively accurate scientific estimate of the depth of an ocean between Japan and the Pacific coast of the U.S. The velocity of the sea wave from Simoda to San Francisco was 369 mph. |
