- Sometimes called seismic sea waves (or, incorrectly, tidal waves), a tsunami is a series of waves generated by large earthquakes that create vertical movement on the ocean floor.
- Tsunamis can reach more than 50 feet in height, move inland several hundred feet and threaten life and property.
- Often, the first wave of a tsunami is not the largest.
- Tsunamis can occur on all coastal regions of the world, but are most common along margins of the Pacific Ocean.
- Tsunamis can travel from one side of the Pacific to the other in a day, at a velocity of 600 miles an hour in deep water.
- A locally generated tsunami may reach the shore within minutes.
[Information from: "Frequently Asked Earthquake Questions" - "Earthquakes - A Whole Lotta Shakin’ Goin’ On" - State of California - Department of Conservation]