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Flashcards in Natural hazards Deck (19)
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1

4 types of plate margins

Constructive
Destructive
Conservative
Collision

2

Layers of the earth

Crust
Mantle
Outer core
Inner core

3

What happens at a constructive plate margin?

Plates are moving apart

4

What happens at a destructive plate margin?

Oceanic and continental plate are moving together

5

What happens at a conservative plate margin?

Plates slide past each other in opposite direction in the same or different speeds

6

What happens at a collision plate?

2 continental plates pushing into eachother as they're the same density

7

What do the plates move due to?

Convection currents

8

How does a volcano form?

Convection currents cause an oceanic plate to subduct under the continental plate. The friction in the subduction zone causes the magma to rise. The crust fills the gap causing magma to rise causing a volcano

9

What is the Pacific ring of fire?

One of the most famous areas for Volcanic activity

10

What is pyroclastic flow?

-Mixture of volcanic ash, rock and other debris
-ejected from volcanoes

11

What are lahars?

Mudflows made from rock debris
-forms from an eruption melting snow of the top of the volcano

12

Ways an earthquake will occur?

-minor tremors
-seismographs
-animal behaviour
-charts showing previous activity
-stress in rocks

13

What is an earthquake?

A build up of pressure from plate margins. When pressure is too much it cracks causing a focus. Energy released from the focus causes seismic waves.

14

What is a focus?

The place in the earth where the plates crack

15

What is the epicentre?

Closest place to the focus, directly above focus

16

Is a tropical storm a low or high pressure event?

Low pressure

17

What is low pressure?

Molecules in the air closer together and cold

18

What is a drought?

A high pressure event, defined as a long period of abnormally dry weather

19

What is a natural hazard?

An event that happens due to natural causes