4. TSUNAMI
What is a Tsunami?
Tsunami Characteristics
Causes of Tsunami
Types of Tsunamis
Ring of fire
Historical Tsunamis
Tsunami Effects
Tsunami signs and Preventions
5. What is a Tsunami?
Tsunami is a series of
water waves caused by
the displacement of
large volume of a body
of water, usually an
ocean.
6. Tsunami Characteristics
In deep water ,Tsunamis can travel at speeds
of even up to 600 mph (jet speed). In
shallow water, as they approach coastlines,
they slow down, bunch up, and can get
enormously tall.
Out in the deep open ocean, the waves are
only one to two feet tall. But when they
approach the shore, waves encounter
shallow water. They slow down and the
waves height increases dramatically and may
reach even up to more than 100 ft.
8. Types of Tsunamis
There are three types of Tsunamis:
Local Tsunami
• 100 km
• One hour
Regional Tsunami
• 100-1000 km
• 1-3 hours
Distant Tsunami
• More than 1000 km
• More than 3 hours
9. Ring of Fire
Tsunamis happen most
frequently in the Pacific Ocean
because of the many large
earthquakes associated with
subduction zones along the
margins of the Pacific Ocean
basin, which is called the "Ring
of Fire". Ninety percent of the
world's earthquakes occur
along the Ring of Fire.
10. Historical Tsunamis
First tsunami was recorded in 1480 B.C. in Eastern Mediterranean, when Minoan
civilization was wiped out.
North and South American records have dated such events back to 1788 for Alaska
and 1562 for Chile. Records of Hawaiian tsunami go back to 1821.Several tsunamis
have occurred throughout many years which include
1883,1929,1933,1946,1952,1958,1960,1979,1983,1992,1998,2004,2006, 2010,2011
and 2013.
Amongst all these, the 2004 Indian Ocean tsunami is among the deadliest natural
disasters in human history with at least 230,000 people killed or missing in 14
countries bordering the Indian Ocean. It was spawned by an earthquake of
magnitude 9.0 off the coast of Sumatra.
16. Tsunami Signs and Prevention
Following are few tsunami signs :
Strong ground shaking from an earthquake
Unusual sea-level fluctuations
Abnormally huge wave
Loud ocean roar
If you see any of these signs, run immediately to some higher ground or
inland, avoiding river valleys.