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TSUNAMI

AMANO MAISEKIYA HIDEHIKO

YAMAGUCHI HIROSHI

CIVIL ENGINEERING ENGLISH 1

2007/2/6

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CONTENTS

ACCIDENTSCASE 1~3

MECHANISMCAUSESOCCURRENCETRANSMISSION

• VELOCITY• HEIGHT

SUBMERGENCE

MITIGATION MEASURESCONCLUSIONS

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ACCIDENTS ~CASE 1~

FIG. 1 Picture of tsunami

1993/07/12

Okushiri Island was

damaged by tsunami.

Big earthquake

Big tsunami

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ACCIDENTS ~CASE 2~

Aona port was damaged

by tsunami.

FIG. 2 Damage of Aona port

FIG. 3 Damage of breakwater

Fishing boat and the breakwater were destroyed.

(http://www.bo-sai.co.jp/sub8.html)

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ACCIDENTS ~CASE 3~

FIG. 4 Damage of Inaho elementary school

Inaho elementary school

was damaged by tsunami.

TSUNAMI DAMAGE A LOT OF INFRASTRUCTURE!!

(http://www.bo-sai.co.jp/sub8.html)

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MECHANISM ~CAUSES~

The causes of tsunamiEarthquakesVolcanic activitiesFalls of meteors

95 ％ of causes is earthquakes!!!!

tsunami is constructed by three parts.

1. OCCURRENCE2. TRANSMISSON3. SUBMERGENCE

FIG. 5 Sequence of tsunami（http://ja.wikipedia.org/wiki/%E6%B4%A5%E6%B3%A2）

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When earthquake occurs,the bottom of the sea raises or sinks.

The reaction from changing crustlifts or pulls down seawater abovethat point.

TSUNAMI OCCURS

FIG. 5-a Before tsunami

FIG . 5-b After tsunami

MECHANISM ~OCCURRENCE~

Mechanism of tsunami

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1. VELOCITY

The velocity of tsunami is only influenced bydepth of water.

For example

VelocityDepth of sea

500m4000m

252km/h712km/h

This is that of Boeing 707!!

10m 36km/h

MECHANISM ~TRANSMISSION~

g×d

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MECHANISM ~TRANSMISSION~

The height of tsunami isinfluenced by depth ofWater. Because depthof shore is low, height becomes too high.

2. HEIGHT

Too dangerous!!Maximum of height

Japan 38,2m (1896, Meijisanrikutsunami)

World 520m (1958, Alaska)

FIG. 6 Relationship of tsunami 　

(http://ja.wikipedia.org/wiki/%E6%B4%A5%E6%B3%A2)

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MECHANISM ~SUBMERGENCE~

FIG. 7-a

FIG. 7-b

Tsunami isdifferent from tidal wave.

Tsunami has potential energy.

Potential energy can concentratein particular topography.

Ex) Saw-toothed coastline

It's too dangerous!!!

Concentration of tsunami

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MITIGATION MEASURES

Actually, there are few provisions.

1. Build a breakwater

2. Live in a concrete building

3. Flee into the second floor if tsunami happens etc.

FIG. 8 　 water gate “byuuo” FIG. 9 Model of “MONE’S HOUSE”(http://www.pref.shizuoka.jp/doboku/buchou1/talk/talk17.htm)

(http://www.k3.dion.ne.jp/~monet/sub2zennkei.html)

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CONCLUSIONS

KNOWLEDGEREFUGERECONSTRUCT