The Restless Earth Flashcards
What are the two types of crust called,and what are the differences between them?
Continental Crust is thicker and less dense.
Oceanic Crust is thinner and more dense.
What are the three types of Plate Margin?
Destructive Margins
Constructive Margins
Conservation Margins
How are Fold Mountains formed?
They form when plates collide at Destructive Plate Margins. The sedimentary rocks that have been built up between them are folded and forced upwards to form mountains.
What do Humans use Fold Mountain areas for?
For Farming Hydro-Electric Power Mining Forestry Tourism
Where are Volcanoes found?
At destructive and constructive plate margins.
How are volcanoes formed at destructive plate margins?
At the destructive plate boundary the oceanic plate goes under as it’s more dense. It gets moved into the mantle,where it is melted and destroyed. This creates a pool of magma,which rises through cracks in the crust called vents,which then erupts onto the surface.
How are Volcanoes formed at Constructive Plate Margins?
The magma rises up into the gap created by the plates moving apart,forming a volcano.
What are the three types of Volcano?
Composite Volcanoes
Shield Volcanoes
Dome Volcanoes
What are the characteristics of a Composite Volcano?
Made up of ash and lava that’s erupted,cooled and hardened into layers.
The lava is thick and flows slowly,hardening quickly,to form a steep sided volcano.
What are the characteristics of a Shield Volcano?
Made up of only lava-which is runny.
It flows quickly and spreads over a large area,forming a low flat volcano.
What are the characteristics of a Dome Volcano?
Made up of only lava. Which is thick,and it flows slowly and hardens quickly,forming a steep sided volcano.
How do Scientists predict Volcano Eruptions?
By monitoring tell-tale signs before an eruption:
Tiny Earthquakes
Escaping Gas
Changes in the shape of the volcano.
What are Supervolcanoes and where do they form?
They are massive volcanoes which are formed at destructive plate margins or over parts of the mantle which are really hot (hotspots).
What are the characteristics of a Supervolcano?
Flat
Cover a large area
Have a caldera
How are Super Volcanoes formed?
Magma rises through cracks in the crust to form a large magma basin beneath the surface. The pressure caused by the Magma creates a circular bulge on the surface which is several kilometres wide. The bulge cracks,creating vents for lava to escape through. This erupts,causing an earthquake and sending up plumes of ash and rock. As the magma basin empties,the bulge collapses. After a big crater is left,called a caldera.
