Of all Earth’s natural hazards, tsunamis are
among the most irregular and infrequent. Yet,
they pose a major threat to coastal populations.
Although tsunamis cannot be prevented, community
preparedness, accurate and timely warnings and effective
response can save lives and protect property. The 2011
tsunami in Japan and the 2004 Indian Ocean tsunami
have focused world attention on the rare but very real
threat of tsunamis and underscored the value of a
comprehensive warning system and an educated public.
A tsunami is a series of ocean waves created by a
sudden displacement of seawater. Most tsunamis are
caused by undersea earthquakes, but they can also be
caused by landslides, volcanic activity, meteorites and
even certain weather-related phenomena. A tsunami
could strike the U.S. coastline at any time and can be
very dangerous to life and property when it reaches the
shore. It may arrive like a fast-rising flood and can strike
with devastating force. Tsunami waves can range in size
from inches to more than a hundred feet high and can
flood low-lying areas more than a mile inland. Waves
may continue for several hours, and the first one may
not be the largest.