A liquid layer made up of iron and nickel. Is extremely hot but not the hottest.
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Continental crust is...
A type of crust that carries land. It is the less dense crust.
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A constructive plate boundary is when..
The plates move apart.
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A destructive plate boundary is when...
The plates move towards each other.
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Define subduction.
When the plate goes under another plate.
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Which best describes convection currents?
Unstable temperatures generated by radioactive decay in core, move plates, diverge near crust pulls plates apart, converge moves plates together.
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Explain what happens at a destructive plate boundary.
1 The oceanic plate denser than continental plate 2 moving together, the oceanic plate forced underneath continental; called subduction 3 Oceanic plate melts to form magma, earthquakes are triggered 4 magma rises through cracks, eruption occurs
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How are fold mountains made and give an example?
As plates push together, the continental crust is squashed together and forced upwards. E.g. Himalayas, Alps
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How are earthquakes measured?
On an instrument called a seismometer using the Richter scale.
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Where can earthquakes occur?
On any type of plate boundary.
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Whats the focus of pressure of an earthquake called?
Epicentre.
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How are earthquakes measured?
On a Richter scale, 0-10
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Social impacts of earthquakes?
Death, injury, burst water pipes, disease spread, re-housing
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Environmental impacts of earthquakes?
Fire damage, landslides, tsunamis, landmarks lost.
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Factors affecting impacts of earthquake?
Closer distance from epicentre, high population, LEDC, busy time of day, high on Richter scale
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How do earthquakes affect LEDC's?
Communication to under developed, homes suffer more damage, building collapse increase death toll, evacuation plans difficult to put into action, clearing up difficult.
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What do volcanic eruptions cause?
Ash, smoke, lava, magma,
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What are shield volcanoes?
Found at constructive boundaries, low gently sloping sides, formed by eruptions of thin runny lava, eruptions frequent but gentle.
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What are composite volcanoes?
Made up of lava and ash layers, found at destructive boundaries, eruptions may be of pyroclastic flow, roll down at high speeds at 400 degrees
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What is pyroclastic flow?
A mixture of hot steam, ash, rock and dust.
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Whats a supervolcano and an example?
Erupts 1000 km3 of material, erupts less frequently, E.g. Yellowstone
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What is basaltic lava?
Fastest flowing, made up of iron and magnesium, expelled from shield volcanoes
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What is andesitic lava?
Flows at a slower rate, originates from stratovolcanoes, block flow
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Preparing and predicting earthquakes?
Detect radon gas, seismometer, laser beams, drills, training, construction of sturdy buildings
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Preparing and predicting volcanoes?
Exclusion zone, evacuations, communications, sulphur gas testing, rising temperatures
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What does VEI stand for?
Volcanic Explosivity Index
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Other cards in this set
Card 2
Front
Continental crust is...
Back
A type of crust that carries land. It is the less dense crust.
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