7/27/2019 FRITA_X.7

1/39

7/27/2019 FRITA_X.7

2/39

Tsunami Description can give a right definition of tsunami,to know the cause of tsunami and where do tsunami occur on

our planet.

7/27/2019 FRITA_X.7

3/39

Tsunami

Description :

1. Definition of Tsunami

2. What causes of Tsunami?

3. Where do tsunamis occurs in the world

7/27/2019 FRITA_X.7

4/39

Tsunami is a Japanese word meaning harbor wave. It

is constituted with two syllables, Japanese language

meaning harbour ("tsu", ) and wave("nami", ).

Tsunami is a wave train or series of waves generated,by impulsive disturbance that vertically displaces the

water column, in water body. Earthquake, landslides,

volcanic eruption, explosion and even the impact of

cosmic bodies like meteorites commonly generate

tsunami. Tsunami savagely attacks coastlines causingdevastating property damage and loss of lives.

7/27/2019 FRITA_X.7

5/39

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 isa 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. Note the normal rise and fall of the

ocean surface, caused by tides, during the early part ofthis record. 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.

7/27/2019 FRITA_X.7

6/39

1. Tsunami can be generated when

the see floor abruptly deforms

and vertically displaces theoverlying water.

2. Tectonic earthquakes are a

particular kind of earthquake that

are associated with the earths

crustal deformation, when theseearthquakes occur beneath the

see, the water above the

deformed area is displayed from

its equilibrium position.

3. Waves are formed as the

displaced water mass, which acts

under the influence of gravity,

attempts to regain its equilibrium

7/27/2019 FRITA_X.7

7/39

Ocean waves are normally

divided into 3 groups,

characterized by depth:

Deep water Intermediate water

Shallow water

Even though a tsunami is

generated in deep water (around

4000 m below mean sea level),tsunami waves are considered

shallow-water waves. As the

tsunami wave approaches the

shallow waters of shore, its time

period remains the same, but itswavelength decreases rapidly,

thus causing the water to pile up

to form tremendous crests, in an

effect known as "shoaling".

7/27/2019 FRITA_X.7

8/39

Most tsunamis are caused by earthquakes generated

in a

subduction zone, an area where an oceanic plate is

being

forced down into the mantle by plate tectonic forces.

The

friction between the subducting plate and the

overriding

plate is enormous. This friction prevents a slow and

steady

rate of subduction and instead the two plates become

" "

Subduction Zones are Potential

Tsunami Locations

7/27/2019 FRITA_X.7

9/39

As the stuck plate continues to descend into the mantle

the motion causes a slow distortion of the overriding

plage.

The result is an accumulation of energy very similar to

the

energy stored in a compressed spring. Energy can

accumulate in the overriding plate over a long period of

time - decades or even centuries.

Accumulated Seismic Energy

7/27/2019 FRITA_X.7

10/39

Energy accumulates in the overriding plate until it

exceeds

the frictional forces between the two stuck plates. When

this happens, the overriding plate snaps back into an

unrestrained position. This sudden motion is the causeof

the tsunami - because it gives an enormous shove to

the

overlying water. At the same time, inland areas of the

overriding plate are suddenly lowered.

Earthquake Causes Tsunami

7/27/2019 FRITA_X.7

11/39

Tsunamis occur most frequently in the Pacific Ocean, butare

a global phenomenon; they are possible wherever large

bodies of

water are found, including inland lakes, where they can be

caused

by landslides.Japan is a nation with the most recorded tsunamis in the

world. The earliest recorded disaster being that of the 684

A.D.

Please refer to the below website of the List of historic

tsunamis by death toll

http://en.wikipedia.org/wiki/List_of_natural_disasters_by_death_t

oll

7/27/2019 FRITA_X.7

12/39

Map of tectonic plates where the earthquake triggered the tsunami

7/27/2019 FRITA_X.7

13/39

7/27/2019 FRITA_X.7

14/39

Definition

Tsunami is a series of sea waves spreading

rapidly in all directions from the area on the seabottom where a large earthquake, volcanic

eruption, or coastal landslide has occurred.

Recabarrenet. al.,I invite you to know the earth, p. 35

Image courtesy NOAAhttp://www.tsunami.noaa.gov/tsunami_story.html

7/27/2019 FRITA_X.7

15/39

Definition

Sea floor movement canbe caused by several

different types ofgeological activity:

Earthquakes

Landslides (~10%)

Submarine volcaniceruptions (< 10%)

Meteorite Impact

LandslideTsunami

EarthquakeTsunami

7/27/2019 FRITA_X.7

16/39

Landslide Tsunami

7/27/2019 FRITA_X.7

17/39

Earthquake Tsunami Formation

From How Stuff Works:

http://science.howstuffworks.com/tsunami.htm

Underwater earthquakes

cause an uplift of one

plate and a subsequent

displacement of water.

The water is pushed

upward above normal

sea level. The resulting

wave can be hundred of

miles long and has been

know to reach heights of

up to 34 ft. The waves

travel as fast or faster

than a commercial jet.

http://science.howstuffworks.com/tsunami.htmhttp://science.howstuffworks.com/tsunami.htmhttp://science.howstuffworks.com/tsunami.htmhttp://science.howstuffworks.com/tsunami.htm

7/27/2019 FRITA_X.7

18/39

Tsunami Generation and

Propagation

QuickTime animation by Professor MihoAoki, University of Alaska-Fairbanks Art

Department, University of Alaska-

Fairbanks of a Tsunami generated by a

subduction zone earthquake.

http://c/Documents%20and%20Settings/INTEL/My%20Documents/Downloads/generation_small.movhttp://c/Documents%20and%20Settings/INTEL/My%20Documents/Downloads/generation_small.movhttp://c/Documents%20and%20Settings/INTEL/My%20Documents/Downloads/generation_small.mov

7/27/2019 FRITA_X.7

19/39

Wave Propagation

Tsunami waves propagate radially from the source.

Tsunami propagation has distinct directionality it willtravel normal to the direction of the fault.

Propagation of the December 24, 2004 Sumatratsunami.

NOAA Animation:http://nctr.pmel.noaa.gov/indo_1204.html

7/27/2019 FRITA_X.7

20/39

Pacific Northwest Model

USGS: Stochastic Model for PotentialTsunamis in the Pacific Northwest.

20 minute simulation

http://walrus.wr.usgs.gov/tsunami/research2.htmlhttp://walrus.wr.usgs.gov/tsunami/research2.htmlhttp://c/Documents%20and%20Settings/INTEL/My%20Documents/Downloads/usgs_hurst_high.movhttp://walrus.wr.usgs.gov/tsunami/research2.htmlhttp://walrus.wr.usgs.gov/tsunami/research2.html

7/27/2019 FRITA_X.7

21/39

In minutes 230,000 people lost their lives, and over 430,000 homeswere reduced to rubble

7/27/2019 FRITA_X.7

22/39

Over 100,000 fishing boats were destroyed. Thelivelihoods of over 5 million people were thrown into jeopardy

7/27/2019 FRITA_X.7

23/39

More than 2,174 miles of roads destroyed. $10billion in damages in barely 24 hours.

7/27/2019 FRITA_X.7

24/39

Effects

Economical Impact

7/27/2019 FRITA_X.7

25/39

Economical Impact

The immediate relief needs in the affected countries in the IndianOcean are gigantic and complicated, and there will be a long termneed for rebuilding in these areas.

The disaster is complicated because there are the effects of the

earthquake near the epicenter (Banda Aceh) and the widespreadeffects of the tsunami wave. In effect, there are two disasters, a very serious earthquake as well

as the effects of the tsunamis generated. The effects are likely to be most severe and apparent for island

economies and countries/cities dependent on the sea and near the

epicenter of the earthquake (Banda Aceh, Andaman and NicobarIslands, Maldives).

7/27/2019 FRITA_X.7

26/39

Undesirable Effects

For the many indigenous fishermen who have no other skills, can nolonger depend on fishing as a means of survival for the time being.

The fish stock has been depleted, as would the fishermen's money.Also, the many of the fishermen's families would have lost their sole

breadwinners, together with the fishing boats and equipment,adding on to their already heightening problems. The tsunamis that affected the coast of Thailand, Indonesia and the

Maldives has destroyed much of the marine biology there, alsodamaging the ecosystem severely.

Even if the fish had detected the incoming tsunami, they would

most probably still have gotten caught up in it, due to its immenseenergy. Any fish trying to swim away from it would also have ended up on

the shores,after being swept ashore. Also, the arrival of a tsunami is marked by a huge receding wave,

which would have left fish flopping on the seabed.

7/27/2019 FRITA_X.7

27/39

Undesirable Effects

Millions of fish were swept ashore by the huge waves, and manymore will continue to die, being unable to survive in the severelydamaged habitat left in the wake of the tsunami.

The marine ecosystem is hence likely to have been affected badly,

with the predators up the food chain, such as dolphins and sharks,dying out due to the lack of food. Many species will not be able toadapt to the sudden change in their lifestyle and will inevitably die.

In addition, even if there were fish to be caught, there would be asubstantial number of people in the region who refuse to consumemarine products such as fish and shellfish, for fear that they couldbe eating the remains of the victims of the tsunami.

Getting them to consume seafood again would be no easy feat. Allthese serve to deal the already battered fishing industry anotherdevastating blow.

7/27/2019 FRITA_X.7

28/39

Undesirable Effects

Fish is also a popular food in these countries due to the affectedcountries being surrounded by water, and the sudden lack of fishand its important nutrients may pose a problem for the people usedto having fish at every other meal.

Seafood farms in countries such as Thailand would also have beendamaged, with their owners suffering enormous losses. Under-Secretary-General for Humanitarian Affairs Jan Egeland said

that relief supplies could be moved to tsunami-hit regions in SriLanka and the Maldives, but ninety percent of the problem remainsin Indonesian archipelago.

He estimated that there are currently over 1.8 million people intsunami-stricken countries in need of food aid around 1 million inIndonesia, and around 700,000 in Sri Lanka, with the remainder inthe Maldives and Somalia.

7/27/2019 FRITA_X.7

29/39

7/27/2019 FRITA_X.7

30/39

Undesirable Effects

In addition, the torrential water deluging entire hectares preventhelicopters from landing. Most of the affected villages were situatedin isolated areas and are extremely hard to get to.

Furthermore, the huge mass of water also broke sewage and water

pipes, contaminating water and food sources. Subsequently, diseases such as cholera, typhoid, dysentery and

dengue then become more rampant. The rotting corpses left behind by the tsunami also helped to spread

diseases to the survivors. Crops, settlements, wildlife, properties were severely destroyed,

with power and communications disrupted, adding on to thedaunting task of rescue work. People clung on to trees for their dear life; some were rescued, but

some were also swept away, right in front of their relatives andfamily members.

The emotional and mental trauma would remain in all those affected

for years, even if they had escaped a watery grave.

7/27/2019 FRITA_X.7

31/39

Undesirable Effects

Skipping to the damage to the economy, the tsunamis of SE Asiahave dealt a heavy blow to the tourism industry in the region.

The huge losses of life suffered by Thailand and the Maldives,which were once extremely popular tourist destinations, only proved

that safety measures in the above countries had been taken lightlyand were inadequate. As such, potential tourists would have lost a sense of security in

visiting these countries. People would also refrain from visiting the countries for fear of

being affected by similar incidences due to this lack of protection.

Furthermore, few people would want to visit a site ravaged by theforces of nature, where countless died, for the time being, eitherout of respect for the dead or due to its pure eeriness itself.

7/27/2019 FRITA_X.7

32/39

Undesirable Effects

The governments of the affected countries would hence losemassive amounts of money which could have been otherwise usedfor improving the general standard of living of the people.

The impact of the tsunami on the Maldives and Phuket is expected

to set the growth rate back for at least two years. It would take halfto two years to rebuild the devastated stretches of beaches, whichwere once tourist havens, and probably even longer to attract backthe tourists.

Countries which would be affected most severely would be Thailandand the Maldives, both of which are still in the developing stage andneed large amounts of resources and finances to provide for anever-growing population. This is especially for the Maldives, whichrelies mainly on tourism revenues to feed its people, and wouldpose a formidable problem.

7/27/2019 FRITA_X.7

33/39

Undesirable Effects

Now, not only do all the above countries stop getting tourism revenue, theyalso have to fork out money and divert government spending to rebuild theresorts and hotels which were destroyed during the tsunami, which wouldbe extremely detrimental to those who lost a lot of assets during thedisaster. Somalia, a country in Africa, would also be badly affected due to

the extreme poverty and lack of government. To quote another example, Banda Aceh was arguably the place which

suffered the most losses during the entire event. Their road to recoverywould be arduous, as the area itself is in political turmoil, with the tsunamiexacerbating the numerous problems it was already facing.

The greatest challenge in the long term however, for all countries, will be inmaking sure that the poor, especially those who fish for a living, those who

are on the margins of the tourist economy and in remoter areas are helpedto recover.

7/27/2019 FRITA_X.7

34/39

Undesirable Effects

On to secondary impacts, they depend very much on the structureof economies and on their tenacity.

The effects are much worse when many other sectors depend a loton the affected sector or if there is a huge impact on the

government expenditure. Generally, the more developed economies are more resilient than

those economies which are less developed. Surprisingly, the large scale economic effects of such natural

disasters are mostly quite short-lived. It has been proven unusual to find large drops in national income or

dips in the annual growth rate from these catastrophes. Sometimes, natural disasters can also have a positive effect,

because of increased spending on the rebuilding of infrastructureand more concerns over safety matters.

7/27/2019 FRITA_X.7

35/39

Undesirable Effects

The refugee camps housing the internally displaced people also hadsqualid conditions, unfit for living in.

Hence many wounds were only hastily treated as there was ashortage of manpower.

Luckily for the injured, many volunteers from over 10 countriesjoined in the relief efforts to provide adequate healthcare servicesfor them.

7/27/2019 FRITA_X.7

36/39

Effects

Environmental Consequences

7/27/2019 FRITA_X.7

37/39

Environmental

Consequences Precious coral reefs and mangrove areas would have been crushed

by the huge tsunami waves that have devastated southern Asia, anenvironmental and economic setback that could take years toreverse.

The reefs around Sri Lanka and Phuket have been severelydamaged due to then bearing the brunt of the forceful walls ofwater.

When the waves get close to shore, their height is amplified andthey release all their energy, decimating everything in their paths.

The atolls of the alluring Maldives and the southern Thai islands

(including Mangrove areas that act as nursery habitats to fish andshrimp) were also destroyed by the strong waves.

7/27/2019 FRITA_X.7

38/39

Environmental

Consequences According to scientists, reef-forming coral grows only about cm,

or 1/5 inch a year, thus for the seaside resorts on the numerousaffected islands to regain their previous splendor could take severalyears to a decade.

The worst marine damage was likely to have been concentrated100m to 1km from shore. Fortunately, large sea mammals such as whales and dolphins

probably suffered little impact. According to Australia's Commonwealth Scientific and Industrial

Research Organization, dolphins can feel disturbances happening in

the water and would have most likely headed for deep water wherethey would be safe. Also, they mostly inhabit the areas far offshore, where the tsunami

has the least damaging capacity.

7/27/2019 FRITA_X.7

39/39

THANKS FOR YOUR ATENTION

NAMA : FRITA LIANY WIYANDARI

KELAS : X.7 (RESBIVENT)

I HOPE THIS PRESENTATION BE USEFULL

ITS ME ->