1) There is a difference between a tidal wave and a tsunami. Tidal waves are much less dangerous and are generated by correlating factors between the sun, moon, and Earth. The wave begins much closer to land so it doesn’t build up in height and strength. Many times, a tidal wave can burn itself out before it reaches land.
Tsunamis are due to earthquakes. As the land shifts in the ocean it pushes the water up and through gravity directs itself towards land; of course, the lower the sea level of the land, the more the wave takes a hard, downward path towards it.
2) The oldest recorded tsunami occurred in 479 BCE. It destroyed a Persian army that was attacking the town of Potidaea in Greece.
3) Around forty years later (439 BCE), a Greek historian published a report that the monster waves hitting Greece were caused by earthquakes.
4) Japan has experienced more devasting tsunamis than any other place in the world; the highest wave that hit the island was 132 feet tall.
5) The largest wave from a tsunami ever recorded occurred in 1964, and it was 220 feet tall. The reason only 136 people died during the tragedy is that Alaska has such a small population; especially on the large mountain the wave crashed into. The tsunami was created due to the largest earthquake ever recorded in the U.S., and it reached 9.2 on the Richter Scale. San Francisco’s devastating earthquake, in 1989, reached 7.9 on the scale but it was much more devastating as around 3,000 people died and around 80% of the city was destroyed.