Tectonic Hazards Flashcards
1
Q
What is convection?
A
- Mantle is heated by the core
- Heated magma rises towards the crust
- It cools, more dense, sinks again
- Repeats
- Causes the plates to move
2
Q
What is the difference between oceanic and continental crust?
A
- Oceanic is heavy, dense, thinner
- Continental is lighter, thicker less dense
3
Q
What is continental drift?
A
Process of plates moving over time which changes the position of continents.
4
Q
Destructive Plate Boundary:
A
- One O plate and C plate push together
- Denser O plate subducts
- O plate sinks, melts , creates magma
- Once the magma reaches the surface, volcanoe
- Phillipine and Eurasian plate
5
Q
Collision Plate Boundary
A
- Two C plates of same density collide
- Push upwards, making fold mountains.
- Himalayas
6
Q
Constructive Boundary:
A
- Plates are moving away from each other
- Creates fissures and faults
- E-16 & Mid-Atlantic Ridge
7
Q
Conservative Plate Boundary:
A
- Plates slide past each other
- Friction builds up until one plate snaps
- Creates an earthquake
8
Q
Focus
A
Where the earthquake begins
9
Q
Epicentre
A
Land directly above the focus is called the epicentre
10
Q
Composite Volcano:
A
- Destructive plate boundary
- Magma is more viscous
- More explosive
- Steep sided volcanoes
- Ash
11
Q
Shield Volcano:
A
- Constructive
- Liquid magma
- Gentle volcano slope
12
Q
Fissure Volcano:
A
- Constructive plate boundary
- Eruption flows from a fault line
13
Q
Caldera Volcano:
A
- Erupts so explosively the magma chamber empties and the crater collapses into itself
14
Q
Hotspot:
A
- Oceanic plate is moving over a particularly hot area of the mantle
- Super plume of hot magma rising towards the crust
- Punches through the plates
15
Q
How to mitigate earthquakes?
A
- Roof made from reinforced cement concrete
- Windows fitted with shatter-proof glass
- Counter weights to the roof to help balance the swaying
