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9 Cards in this Set
- Front
- Back
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What are tsunamis? |
series of ocean waves
send surges of water
onto land |
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What are tsunamis typically caused by? |
under sea earthquakes
at destructive plate boundaries |
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What conditions are needed for a tsunami to occur? |
earthquake 6/7 richter scale
sea bed lifted/lowered by earthquake
epicentre of earthquake near earths surface |
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In what geographical location do most tsunamis occur? |
most occur in the ring of fire |
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Other than earthquakes, what two other instances can trigger tsunamis? |
under water volcanoes
landslides |
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Draw/explain the formation of a tsunami diagram: |
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Outline a tsunami formation:
initial triggering |
-plate subducts -gets cause -tension -tension to great -plate comes loose/shifts -tension released suddenly -earth quake |
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Outline a tsunami formation:
inital reaction after the earthquake |
-energy from quake vertically jolts seabed up/downwards -displaces hundreds of cubic km of water -water column shoved up above sea level |
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Outline a tsunami formation
final occurrence: |
-horizontally large waves move through ocean -move away from epicentre -deep water = great speeds -shallow water = friction - forces water up wards -water increases in height near coast -water line retreats exposing hundred metres of beach/sea bed |
