TSUNAMI

A tsunami is a series of waves created when water is moved very quickly. Underwater earthquakes are the most common causes of tsunamis, but underwater volcanic activity can also trigger a displacement in the water, and create a mega-wave.

View of a Tsunami Taken By A Satellite

A tsunami is a

series of huge

waves that

happen after a

undersea

disturbance,

such as an

earthquake or

volcano eruption.

WHAT IS TSUNAMIBASICALLY??

CONCEPT:

·Tsunamis are the worst natural

disaster; they happen mostly in

the Pacific Ocean, but may also

occur any where in the world

with a large body of water.

·Tsunamis are large wave of

water that is caused by an

earthquake in the ocean.

Most destructive tsunamis are caused by

earthquakes; other causes may be volcanic

eruptions, landslides, and rarely even a comet

hitting the sea.

Causes of Tsunami

Earthquake

Volcanic eruption

Underwater explosions

Meteorite impacts

It depends on the earthquake on the size of the Tsunamis big or small.

They travel hundreds of miles and cause great devastation to any one in its way.

Tsunamis start at speech at .85 mach, which is close to 600 MPH, and then slow down to around 30 MPH when they reach land.

•An underground earthquake, rock slide, or volcanic eruption can shift the water

•Height increases as the Tsunami reaches closer to shore

On average, two damaging tsunamis occur each year. The speed of a tsunami can go up to 600 mph, the average speed of a jet.

Hawaii is the riskiest state for tsunamis. States such as California, Washington, and Oregon

are also affected by damaging tsunamis Internationally tsunamis are common around the Pacific Ocean and the Mediterranean Sea.

Tsunami "Wave Train"Many people have the mistaken belief that

tsunamis are single waves. They are not.

Instead tsunamis are "wave trains" consisting

of multiple waves. The chart below is a tidal

gauge record from Onagawa, Japan beginning

at the time of the 1960 Chile earthquake. Time

is plotted along the horizontal axis and water

level is plotted on the vertical axis. Then

recorded are a few waves a little larger than

normal followed by several much larger waves.

In many tsunami events the shoreline is

pounded by repeated large waves.

Warning Signs

• An earthquake is a natural tsunami warning. If you feel a strong quake do not stay in a

place where you are exposed to a tsunami. If you hear of an earthquake be aware of the

possibility of a tsunami and listen to the radio or television for additional information.

Remember that an earthquake can trigger killer waves thousands of miles across the

ocean many hours after the event generated a tsunami.

•Witnesses have reported that an approaching tsunami is sometimes preceded by a

noticeable fall or rise in the water level. If you see the ocean receding unusually rapidly

or far it's a good sign that a big wave is on its way. Go to high ground immediately.

•Many people were killed by the Indian Ocean tsunami because they went down to the

beach to view the retreating ocean exposing the seafloor. Experts believe that a receding

ocean may give people as much as five minutes' warning to evacuate the area.

• Remember that a tsunami is a series of waves and that the first wave may not be the

most dangerous. The danger from a tsunami can last for several hours after the arrival

of the first wave. A tsunami wave train may come as a series of surges that are five

minutes to an hour apart. The cycle may be marked by a repeated retreat and advance of

the ocean.

•Survivors of the Indian Ocean tsunami reported that the sea surged out

as fast and as powerfully as it came ashore. Many people were seen

being swept out to sea when the ocean retreated.

•A tsunami surge may be small at one point of the shore and large at

another point a short distance away. Do not assume that because there is

minimal sign of a tsunami in one place it will be like that everywhere

else.

• Tsunamis can travel up rivers and streams that lead to the ocean. Stay

away from rivers and streams that lead to the ocean as you would stay

away from the beach and ocean if there is a tsunami.

• It's always a good idea to keep a store of emergency supplies that

include sufficient medications, water, and other essentials sufficient for

at least 72 hours. Tsunami, earthquake, hurricane—an emergency can

develop with little or no warning.

HISTORY OF TSUNAMI

The Roman historian Ammianus Marcellinus (Res Gestae 26.10.15-19) described the typical sequence of a tsunami, including an incipient earthquake, the sudden retreat of the sea and a following gigantic wave, after the 365 A.D. tsunami devastated AlexandriaWhile Japan may have the longest recorded history of tsunamis, the sheer destruction caused by the 2004 Indian Ocean earthquake and tsunami event mark it as the most devastating of its kind in modern times, killing around 230,000 people. The Sumatran region is not unused to tsunamis either, with earthquakes of varying magnitudes regularly occurring off the coast of the island.

LIST OF TSUNAMIS OF PAST 3YRS

*On Jan 4, 2010, two powerful earthquakes

measuring 6.5 and 7.2 on the Richter scale hit

the western part of the Solomon Islands, followed

by a number of smaller quakes. It triggered a

tsunami that left about 1,000 homeless.

**On Feb 27, 2010, an 8.8-magnitude earthquake

hit Chile, triggering tsunami warnings along the

coasts of the Pacific Ocean.

Disaster Date Affected (no. ofpeople)

Sri Lanka 2004 1,019,306

India 2004 654,512

Indonesia 2004 532,898

Somalia 2004 105,083

Thailand 2004 67,007

Indonesia 2006 35,543

Maldives 2004 27,214

Myanmar 2004 15,700

Papua New Guinea

1998 9,867

Malaysia 2004 5,063

Disaster Date Killed (no. of people)

Indonesia 2004 165,708

Sri Lanka 2004 35,399

India 2004 16,389

Thailand 2004 8,345

Papua New Guinea

1998 2,182

Indonesia 2006 802

Somalia 2004 298

Maldives 2004 102

Vanuatu 1997 100

Malaysia 2004 80

Japan was hit by a 9.0 magnitude earthquake on March

11, 2011, that triggered a deadly 23-foot tsunami in the

country's north. The giant waves deluged cities and rural

areas alike, sweeping away cars, homes, buildings, a

train, and boats, leaving a path of death and devastation

in its wake. Video footage showed cars racing away from

surging waves. The earthquake—the largest in Japan's

history—struck about 230 miles northeast of Tokyo. The

Pacific Tsunami Warning Center issued warnings for

Russia, Taiwan, Hawaii, Indonesia, the Marshall Islands,

Papua New Guinea, Australia, and the west coasts the

U.S., Mexico, Central America, and South America.

According to the official toll, the disasters left 15,839

dead, 5,950 injured, and 3,642 missing.

CONSEQUENCES..

BEFORE TSUNAMI

AFTER TSUnaMI

Tsunamis damage tourism. Also, people are faced with re-building, which is difficult because the people may not have enough money to do so.

DebrisTrashWasteTrees are uprootedRemains

Facts About Tsunamis

•Tsunami is should not be known as tidal waves.

Tsunamis are sometimes incorrectly called "tidal

waves" -- tsunamis are not caused by the tides (tides

are caused by the gravitational force of the moon on

the sea). Regular waves are caused by the wind.

•If the first part of a tsunami to reach land is a

trough—called a drawback—rather than a wave

crest, the water along the shoreline recedes

dramatically, exposing normally submerged areas.

•Most tsunamis, about 80 percent, happen within the Pacific

Ocean’s “Ring of Fire,” a geologically active area where

tectonic shifts make volcanoes and earthquakes common.

•A tsunami may be less than a foot (30 centimeters) in height

on the surface of the open ocean, which is why they are not

noticed by sailors. But the powerful shock wave of energy

travels rapidly through the ocean as fast as a commercial jet.

Once a tsunami reaches shallow water near the coast, it is

slowed down. The top of the wave moves faster than the

bottom, causing the sea to rise dramaticall

As a tsunami leaves the deep water of the open ocean and travels into the shallower water . A tsunami travels at a speed that is related to the water depth . As the water depth decreases, the tsunami slows. The tsunami's energy flux, which is dependent on both its wave speed and wave height, remains nearly constant. Consequently, as the tsunami's speed diminishes as it travels into shallower water, its height grows. Because of this shoaling effect, a tsunami, imperceptible at sea, may grow to be several meters or more in height near the coast. When it finally reaches the coast, a tsunami may appear as a rapidly rising or falling tide.

They can travel at about 600 km an hour across deep oceans (as fast as some jet planes), and can be 10-30 meters high when they reach land.

Tsunami is a Japanese word with the English translation, "harbor wave."

Do not get fooled by the sizes of the waves, a tsunami can be more dangerous than you

think. Each wave may get bigger. Once you see a tsunami it is too late to escape. A

tsunami is a series of waves, not a single wave, so don’t doubt the dangers.

TSUNAMI WARNING SYSTEM

Communication & Transmission of Tsunami Warning to Localities & Civil Defense Authorities

Signboard

TSUNAMIＷＡＲＮＩＮＧ

Central Government

ＴＶ/Radio Station

TSUNAMIＷＡＲＮＩＮＧ

Radio

TV（Telops, Warning maps）

TSUNAMI

ＷＡＲＮＩＮＧ

Local government

13

Safe Evacuation Route

Appropriate Risk Awaweness of Local Communities

Understanding of Hazardous Areas

+Early Warning

=

Safe Evacuation

• Continue listening to a NOAA Weather Radio, Coast Guard emergency frequency station, or other reliable source for emergency information

• Help injured or trapped persons• Use the telephone only for emergency calls• Stay out of the building if waters remain

around it• Examine walls, floors, doors, staircases,

and windows to make sure that the building is not in danger of collapsing.

• Inspect foundations for cracks or other damage

Donations done under the Prime Minister Relief Fund.

Rice, mats, medicines were provided.

ITC distributed over 1 lakhshirts to the victims.

New houses were provided.

AWARNESS PROGRAMS LIKE

SKITS, STAGE SHOWS….

PREPARATIONS OF CHARTS AND BEING AWARE ABOUT TSUNAMI, ITS AFFECTS AND PREVENTION METHODS….

A PRESENTATION BY

P.R.GAYATHRI…

CLASS: X