About Tsunamis
Tsunamis are NOT surfing waves!!! Never
attempt to surf or ride a tsunami! Although a deadly
tsunami wave may have the same height as a surfing wave,
its characteristic is turbulent, unpredictable, powerful,
rubble filled, and deadly. A tsunami is series of waves
powerful enough to move house-sized boulders weighing many
tons.
A Tsunami can move faster than a person
can run. Unlike surfing waves which quickly wash up
and down the shore, the crest of the next tsunami wave is
out on the horizon which allows its waves to keep coming
and coming far inland with tremendous power. A tsunami event
can last several hours and destroy everything in its path.
A tsunami is a series of great waves most
commonly caused by violent movement of the sea floor - usually
an earthquake. Tsunamis are also caused by nearshore or
underwater landslides, or volcanic eruptions. This differs
from regular ocean waves that are generated from the wind.
Tsunami are characterized by great speed (up to 590 mph),
long wave length (up to 120 miles), long period between
successive crests (varying from 5 minutes to a few hours,
generally 10 to 60 minutes), and low height in the open
sea. Often the first wave of a tsunami may not be the largest.
The danger from a tsunami can last for several hours after
the arrival of the first wave. Sometimes a tsunami causes
the water near the shore to recede, exposing the ocean floor.
Tsunami can be very large. In coastal areas their height
can be as great as 30 feet or more (100 feet in extreme
cases), and they can move inland several hundred feet. Tsunami
can travel up rivers and streams that lead to the ocean.