TsunamisTsunamisTsunamisTsunamis

Jonny and DannyJonny and DannyJonny and DannyJonny and Danny

What are Tsunamis?What are Tsunamis?WHAT IS A TSUNAMI? –

• A wave train, (or series of waves), generated in a body of water, by a disturbance that vertically displaces the water column.

• Essentially, Tsunamis are caused/triggered by other natural hazards.

• Tsunamis savagely attack coastlines, causing devastating property damage and loss of life.

WHAT IS A TSUNAMI? –

• A wave train, (or series of waves), generated in a body of water, by a disturbance that vertically displaces the water column.

• Essentially, Tsunamis are caused/triggered by other natural hazards.

• Tsunamis savagely attack coastlines, causing devastating property damage and loss of life.

Tsunamis can:– Travel 500km/h– Be 30 (up to 100) feet

high (10m up to 30m)– Flood several hundred

metres inland– A tsunami consists of a

series of waves. Often the first wave may not be the largest.

– Sometimes a tsunami causes the water near the shore to recede, exposing the ocean floor.

– Large rocks weighing several tons along with boats and other debris can be moved inland hundreds of feet by tsunami wave activity.

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

Tsunamis can:– Travel 500km/h– Be 30 (up to 100) feet

high (10m up to 30m)– Flood several hundred

metres inland– A tsunami consists of a

series of waves. Often the first wave may not be the largest.

– Sometimes a tsunami causes the water near the shore to recede, exposing the ocean floor.

– Large rocks weighing several tons along with boats and other debris can be moved inland hundreds of feet by tsunami wave activity.

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

WHAT ARE THE CAUSES OF TSUNAMIS ?

WHAT ARE THE CAUSES OF TSUNAMIS ?

Tsunamis – • Tsunamis are large water waves,

typically generated by seismic activity, that have historically caused significant damage to coastal communities throughout the world.

Tsunamis – • Tsunamis are large water waves,

typically generated by seismic activity, that have historically caused significant damage to coastal communities throughout the world.

How do landslides, volcanic eruptions and cosmic collisions generate Tsunamis ? –•Tsunamis can be generated by any disturbance that displaces a large water mass from its equilibrium position.

• Earthquakes, explosions, and even the impact of

cosmic bodies (i.e. meteorites) can generate tsunamis.

How do landslides, volcanic eruptions and cosmic collisions generate Tsunamis ? –•Tsunamis can be generated by any disturbance that displaces a large water mass from its equilibrium position.

• Earthquakes, explosions, and even the impact of

cosmic bodies (i.e. meteorites) can generate tsunamis.

Explosions, landslides and Earthquakes provide energy that violently displaces the water upwards

Explosions, landslides and Earthquakes provide energy that violently displaces the water upwards

This energy Travels as a wave, easily propagated through the oceanThis energy Travels as a wave, easily propagated through the ocean

EruptionEruption“Land” Slide “Land” Slide

EarthquakeEarthquake

•Earthquake generated Tsunamis – Water column disturbed by the uplift/subsidence of the sea floor.

•A violent submarine Volcanic eruption can create an impulsive force that uplifts the water column and generates a Tsunami.

• Super marine landslides and cosmic body impacts disturb the water from above. Tsunamis generated from these mechanisms dissipate quickly and rarely affect coastlines distant from the source area.

•Earthquake generated Tsunamis – Water column disturbed by the uplift/subsidence of the sea floor.

•A violent submarine Volcanic eruption can create an impulsive force that uplifts the water column and generates a Tsunami.

• Super marine landslides and cosmic body impacts disturb the water from above. Tsunamis generated from these mechanisms dissipate quickly and rarely affect coastlines distant from the source area.

The island of La Palma, in the Canaries is unstable.

Half a Trillion tonnes of rock could slip into the sea at any time.

The Tsunami generated could be 500m high, travel at 800km/h and could potentially destroy the American East coast.

The island of La Palma, in the Canaries is unstable.

Half a Trillion tonnes of rock could slip into the sea at any time.

The Tsunami generated could be 500m high, travel at 800km/h and could potentially destroy the American East coast.

Where do Tsunamis Happen?

Where do Tsunamis Happen?

Tsunamis occur on coastlines of wide oceans, with active plate boundaries within close proximityJapan, Australia, New Zealand and the USA are prone to Tsunamis in the Pacific

Tsunamis occur on coastlines of wide oceans, with active plate boundaries within close proximityJapan, Australia, New Zealand and the USA are prone to Tsunamis in the Pacific

New GuineaNew Guinea

JapanJapan

Japan is famous for Tsunamis, which means “harbour wave”They occur when the energy of the wave hits shallower water, so are very dangerous to land on shallow continental shelves.

Japan is famous for Tsunamis, which means “harbour wave”They occur when the energy of the wave hits shallower water, so are very dangerous to land on shallow continental shelves.

Impacts of TsunamisImpacts of Tsunamis

• Social Impacts– People Killed– Homes and

Business Destroyed– Livelihood lost– Homelessness– Lack of Basic

Amenities– Disease – Forced Migration

• Social Impacts– People Killed– Homes and

Business Destroyed– Livelihood lost– Homelessness– Lack of Basic

Amenities– Disease – Forced Migration

• Economic Impacts– Businesses

Damaged– Loss of Tourism– Loss of Earnings– Cost of

Repair/Defence– Cost of Insurance– Harbours/Fishing

Fleets Damaged– Agriculture Damage

• Land Flooded• Salinisation• Livestock

Drowned/Diseased/Escaped

• Economic Impacts– Businesses

Damaged– Loss of Tourism– Loss of Earnings– Cost of

Repair/Defence– Cost of Insurance– Harbours/Fishing

Fleets Damaged– Agriculture Damage

• Land Flooded• Salinisation• Livestock

Drowned/Diseased/Escaped

• Environmental Impacts– Habitats Flooded

• Salinisation• Fresh Water

Sources Become Salty

• Food Sources Lost• Shelter Lost• Forced Migration

– Animals Killed• Drowned• Disease

– Reefs Damaged

• Environmental Impacts– Habitats Flooded

• Salinisation• Fresh Water

Sources Become Salty

• Food Sources Lost• Shelter Lost• Forced Migration

– Animals Killed• Drowned• Disease

– Reefs Damaged

LEDC: Papua/New Guinea

LEDC: Papua/New Guinea

• 17th July, 1998• Caused by a 7.0

Earthquake, on a Sub-ducting Boundary.

• 3 Successive Waves

• Villages of Sissano, Warupu, Arop and Malol destroyed

• 17th July, 1998• Caused by a 7.0

Earthquake, on a Sub-ducting Boundary.

• 3 Successive Waves

• Villages of Sissano, Warupu, Arop and Malol destroyed

Sissano Lagoon

Impacts in New GuineaImpacts in New Guinea

• AT LEAST 2100 people killed.

• 5,000+ displaced• 15,000 people

lived in Tsunami area

• Trees uprooted, farmland flooded, debris up to 500m inland

• AT LEAST 2100 people killed.

• 5,000+ displaced• 15,000 people

lived in Tsunami area

• Trees uprooted, farmland flooded, debris up to 500m inland

MEDC: JapanMEDC: Japan• Japan experiences

tsunamis because of its location in the Pacific, and close to tectonic boundaries.

• They can flood large areas of the predominantly coastal communities.

• They are engrained within the Japanese psyche, causing a great deal of fear around Japan.

• July 1993– 7.8 earthquake, 180+ killed, $600million in damage.

• Japan experiences tsunamis because of its location in the Pacific, and close to tectonic boundaries.

• They can flood large areas of the predominantly coastal communities.

• They are engrained within the Japanese psyche, causing a great deal of fear around Japan.

• July 1993– 7.8 earthquake, 180+ killed, $600million in damage.

Impacts on JapanImpacts on Japan• Huge economic

loss• Fishing industry

damaged• Cost of monitoring,

and coastal defences.

• Relatively low death toll

• Impact on Japanese “fatalistic” psyche

• Huge economic loss

• Fishing industry damaged

• Cost of monitoring, and coastal defences.

• Relatively low death toll

• Impact on Japanese “fatalistic” psyche