Unit 1A Flashcards
What’s inside the earth?
Core
outer core
mantle
crust
What are the two types of crust?
Oceanic Crust
Continental Crust
What is a Plate Margin?
Place where two plates meet.
What is a destructive plate margin?
Where two plates are moving towards each other.
Where an oceanic plate meets a continental plate, the denser oceanic plate is forced down into the mantle and destroyed.
This creates volcanoes and ocean trenches.
How are mountain ranges created?
Two continental plates meet, the plates collide and the ground is folded and forced upwards to create mountain ranges.
What is a Constructive plate margin?
Constructive margins are where two plates are moving away from each other.
Magma rises from the mantle to fill the gap and cools, creating new crust.
What is a Conservative Margin
Conservative margin are where two plates are moving sideways past each other, or they are moving in the same direction at different speeds.
Crust isn’t created or destroyed.
How are volcanoes formed?
At destructive plate margins, the oceanic plate goes under the continental plate because it is more dense.
The oceanic plate goes into the mantle where it is melted and destroyed.
Magma rises through cracks in the crust called vents.
Magma erupts into the surface forming a volcano.
What happens when a volcano erupts?
It emits lava and gases. Some volcanoes emit lots of ashes which can cover the land and block out the sun.
People may find it hard to breath.
Where does Earthquakes occur?
Destructive margins- the tension builds up when one plate gets stuck as it’s moving down past each other into the mantle
Constructive- tensions builds along cracks within the plates as they move away from each other.
Conservative Margins- tensions build up when the plates are grinding past each other .
This sends out shock waves. (VIBRATIONS)
How do we measure Earthquakes?
Using the moment magnitude scale.
What does the word Logarithmic mean?
It means that a magnitude 7 earthquake is 10 times more powerful than a magnitude 6 earthquake.
What are the Primary effects of an earthquake?
Buildings and bridges collapse.
Homes are destroyed.
People are injured or killed by collapsed buildings.
Roads, railways and airports are damaged.
Electricity cables, gas and water pipes and communication networks are damaged.
Cutting of supplies.
What are the secondary effects of an earthquake?
People are left homeless.
Shortage of clean water.
Lack of proper sanitisation meaning disease can spread.
Due to blocked or destroyed roads, aid and emergency vehicles cant get through, and trade is difficult.
Businesses are damaged or destroyed causing unemployment.
Repairs and reconstruction can be very expensive.
