Curtis Bellisi, age 14, of Montgomery, Ala., for his question:

WHAT CAUSES A TIDAL WAVE?

Destructive tidal waves are caused by hurricanes or by undersea earthquakes, called seaquakes. Hurricane Hugo just a few weeks ago brought some to Caribbean area and to parts of the eastern seaboard in the United States.

Tidal waves are not related to true tides. Many scientists call them (ital) tsunami, (unital) the Japanese word for storm wave. Hurricane related tidal waves are caused by unbelievably strong winds.

Seismographs are used by scientists to predict almost exactly when a tidal wave will arrive at a given seacoast. An earthquake off the Aleutians, for example, might cause a tidal wave that will hit the coast of Hawaii.

In 1755, a tidal wave 50 feet high hit Lisbon, Portugal. Great damage was suffered in Galveston, Texas, when a tidal wave hit there in 1900. More than 200,000 were killed when a cyclone and tidal wave hit Bangladesh in 1970.  A giant tidal wave struck the islands of the South Pacific in 2006 and caused tremendous damage of property and thousands died as a result.