Tsunamis Pres
DONE BY TAMOY LOGAN
GRADE 8E
What is a Tsunamis?
Tsunami are waves caused by sudden movement of the ocean due to earthquakes, landslides on the sea floor, land slumping into the ocean, large volcanic eruptions or meteorite impact in the ocean.
•
Tsunamis generally consist of a series of waves withperiods ranging from minutes to hours, arriving in a so-called
"wave train".[4] Wave heights of tens of metres can be generated by large events. Although the impact of tsunamis is limited to coastal areas, their destructive power can be enormous and they can affect entire ocean basins; the 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history with at least 290,000 people killed or missing in 14 countries bordering the Indian Ocean.
What causes
Tsunamis?
1.
Earthquakes
→ Most tsunami are caused by large earthquakes on the seafloor when slabs of rock move past each other suddenly, causing the overlying water to move. The resulting waves move away from the source of the earthquake event.
Landslides
Underwater landslides can cause
2.
tsunami as can terrestrial land which slumps into the ocean.
3. Volcanic eruptions
Less common are tsunami initiated by volcanic
eruptions. These occur in several ways:
destructive collapse of coastal, island and underwater volcanoes which result in massive landslides pyroclastic flows, which are dense mixtures of hot blocks, pumice, ash and gas, plunging down volcanic slopes into the ocean and pushing water outwards
a caldera volcano collapsing after an eruption causing overlying water to drop suddenly.
The Size of a
Tsunami
• Tsunamis have an extremely long wavelength
(wavelength is the distance between the crest
(top) of one wave and the crest of the next wave) -- up to several hundred miles long. The period (the time between two successive waves) is also very long -- about an hour in deep water.
• In the deep sea, a tsunami's height can be only about 1 m (3 feet) tall. Tsunamis are
GRADE 8E
What is a Tsunamis?
Tsunami are waves caused by sudden movement of the ocean due to earthquakes, landslides on the sea floor, land slumping into the ocean, large volcanic eruptions or meteorite impact in the ocean.
•
Tsunamis generally consist of a series of waves withperiods ranging from minutes to hours, arriving in a so-called
"wave train".[4] Wave heights of tens of metres can be generated by large events. Although the impact of tsunamis is limited to coastal areas, their destructive power can be enormous and they can affect entire ocean basins; the 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history with at least 290,000 people killed or missing in 14 countries bordering the Indian Ocean.
What causes
Tsunamis?
1.
Earthquakes
→ Most tsunami are caused by large earthquakes on the seafloor when slabs of rock move past each other suddenly, causing the overlying water to move. The resulting waves move away from the source of the earthquake event.
Landslides
Underwater landslides can cause
2.
tsunami as can terrestrial land which slumps into the ocean.
3. Volcanic eruptions
Less common are tsunami initiated by volcanic
eruptions. These occur in several ways:
destructive collapse of coastal, island and underwater volcanoes which result in massive landslides pyroclastic flows, which are dense mixtures of hot blocks, pumice, ash and gas, plunging down volcanic slopes into the ocean and pushing water outwards
a caldera volcano collapsing after an eruption causing overlying water to drop suddenly.
The Size of a
Tsunami
• Tsunamis have an extremely long wavelength
(wavelength is the distance between the crest
(top) of one wave and the crest of the next wave) -- up to several hundred miles long. The period (the time between two successive waves) is also very long -- about an hour in deep water.
• In the deep sea, a tsunami's height can be only about 1 m (3 feet) tall. Tsunamis are