What are tsunamis?
Why talk about tsunamis?
All tsunamis are potentially, if rarely, dangerous. Twenty-four tsunamis have caused damage in
the United States and its territories in the past 200 years. Since 1946, six tsunamis have killed
more than 350 people and caused significant property damage in Hawaii, Alaska, and along the
West Coast. Tsunamis have also occurred in Puerto Rico and the Virgin Islands. When a
tsunami comes ashore, it can cause great loss of life and property damage. Tsunamis can travel
upstream in coastal estuaries and rivers, with damaging waves extending farther inland than the
immediate coast. A tsunami can occur during any season of the year and at any time, day or
night.
What are tsunamis?
Tsunamis are large ocean waves generated by major earthquakes beneath the ocean floor or
major landslides into the ocean. Tsunamis caused by nearby earthquakes may reach the coast
within minutes. When the waves enter shallow water, they may rise to several feet or, in rare
cases, tens of feet, striking the coast with devastating force. People on the beach or in low
coastal areas need to be aware that a tsunami could arrive within minutes after a severe
earthquake. The tsunami danger period can continue for many hours after a major earthquake.
Tsunamis also may be generated by very large earthquakes far away in other areas of the
ocean. Waves caused by these earthquakes travel at hundreds of miles per hour, reaching the
coast several hours after the earthquake. The International Tsunami Warning System monitors
ocean waves after any Pacific earthquake with a magnitude greater than 6.5. If waves are
detected, warnings are issued to local authorities who can order the evacuation of low-lying
areas if necessary.
How can I protect myself from a tsunami?
If you are in a coastal community and feel the shaking of a strong earthquake, you may have
only minutes until a tsunami arrives. Do not wait for an official warning. Instead, let the strong
shaking be your warning, and, after protecting yourself from falling objects, quickly move away
from the water and to higher ground. If the surrounding area is flat, move inland. Once away
from the water, listen to a local radio or television station or NOAA Weather Radio for
information from the Tsunami Warning Centers about further action you should take.
Even if you do not feel shaking, if you learn that an area has experienced a large earthquake
that could send a tsunami in your direction, listen to a local radio or television station or NOAA
Weather Radio for information from the Tsunami Warning Centers about action you should take.
Depending on the location of the earthquake, you may have a number of hours in which to take
appropriate action.
Posted by Aneka Tips
on 17.26. Filed under