The Restless Earth, flashcards and questions

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  • Created by: Alicia
  • Created on: 19-04-13 16:51
What is the Earth made up of?
Crust, Mantle, Inner Core, Outer Core.
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What are the two types of crust?
Oceanic and Continental
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What is the difference between these two types of crust?
Oceanic = thin and dense Continental = thick and less dense
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Name the 3 types of plate margins.
Destructive, Constructive, Conservative
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What happens at a destructive plate margin?
Oceanic meets continental, Oceanic forced down and destroyed.Volcanoes, Fold Mountains, Ocean Trenches and earthquakes.
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What happens at constructive plate margins?
Oceanic plates move apart, the space created allows magma to rise magma cools and creates new crust. Creates Volcanoes, Mountains and Earthquakes
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What happens at conservative plate margins?
Two continental plates move past eachother at different speeds and/or different directions. Common cause of earthquakes.
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How are fold mountains formed?
Fold mountains are formed when plates collide(destructive plate margins) sediment builds up under the sea, the sediment is compressed (as the two plates move towards each other) and folds to form a fold mountain
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What do the words Anticline, Syncline and Recumbent mean?
Anticline: a slope folding downwards on both sides Syncline: a slope folding upwards on both sides Recumbent: Over fold
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What are ocean trenches?
They're formed in a subduction zone at destructive plate margins, inaccessible to humans, there are opportunities for fishing and drilling for oil and gas, deepest trench = Marianas Trench
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What type of volcanoes do destructive plate margins make and how?
Composite cone volcanoes: 1: Oceanic plate =destroyed, pool of magma forms 2: Magma rises through the vents 3: Magma erupts onto the surface where it is called lava, forming a volcano.
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What type of volcanoes do constructive plate margins make and how?
Shield Volcanoes: 1: Magma rises into the gap created by the plate moving apart 2: Magma rises through the vents 3: The magma erupts onto the surface where it is known as lava, forming a volcano
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What are the properties of a shield volcano? Name an example.
Wide base, Gentle slopes, Frequent eruptions, non-violent eruptions with Basic Lava, made of lava only, Examples, Mauna Loa, Hawaii
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What are the properties of composite cone volcanoes? Name an example.
Tall cone, narrow base, steep sides, long dormant periods, violent explosions with acid lava, made of alternate layers of ash and lava. Example: Vesuvius, Italy
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What are the effects of a volcano?
Ash and volcanic bombs are thrown out, Pyroclastic flows( hot gases, ash and steam) causes damage, mud flows called lahars form when hot ash melts ice
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How is a caldera formed?
When a volcano is dormant for a long period of time a plug forms, when this plug is blown out, it leaves a large crater called a caldera.
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How can you predict volcanic eruptions?
Signs include: Tiny earthquakes, escaping gas, bulges and changing shape.
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What are the effects of supervolcanoes?
Affect farming as crops and animals would die, damaged communication, great loss of life, global cooling would occur, 1000km³ of ash produced(this would cause a volcanic winter)
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How do earthquakes occur at destructive plate margins?
Tension builds up when one plate gets stuck as it moves down
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How do earthquakes occur at constructive plate margins?
Tension builds up as the plate moves away
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How do earthquakes occur at conservative plate margins?
Tension builds up when plates jerk past eachother
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What is the focus, epicentre and shockwaves with regards to earthquakes?
Focus: Point of the earthquakes origin Epicentre: Point on Earth's surface directly above the focus(shockwaves are most strongest here) Shockwaves: cause the ground to shake
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What is the Richter scale?
Measures magnitude, using a seisometer. It is logarihmic: 1-2 = unfelt, 5+ = major
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What is the Mercalli scale?
Measured in roman numerals, measures the effects, using observations, it goes from I to XI.
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How can we predict exact details of an earthquake?
Changes in the height of the land, levels of underground water, animal behaviour
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Why is the impact higher in LEDC's?
Lack of preparation, Less emergency services, require foreign aid(time consuming), poor communications, diseases spread easily due to lack of sanitation, few educated experts to give advice.
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Other cards in this set

Card 2

Front

What are the two types of crust?

Back

Oceanic and Continental

Card 3

Front

What is the difference between these two types of crust?

Back

Preview of the front of card 3

Card 4

Front

Name the 3 types of plate margins.

Back

Preview of the front of card 4

Card 5

Front

What happens at a destructive plate margin?

Back

Preview of the front of card 5
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