Chapter 5 - Hazards - Complete Flashcards Preview

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Flashcards in Chapter 5 - Hazards - Complete Deck (126)
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1

Define a hazard?

Something that's a potential threat to human life or property

2

Define natural hazard?

A hazard caused by the earth and our atmosphere

3

Define geophysical hazard?

Caused by land processes
- Earthquakes
- Volcanic eruptions
- Landslides
- Tsunamis

4

Define atmospheric hazards?

Caused by climatic processes
- Tropical cyclones
- Storms
- Droughts
- Extreme hot/ cold weather
- Wildfires

5

Define hydrological hazards?

Caused by water movement
- Floods
- Avalanches

6

Define disaster?

When a hazard actually seriously affects humans.

7

What's the difference between a natural hazard and a disaster?

A natural hazard is a volcano erupting in a deserted place but becomes a disaster when it affects people.

8

Define risk?

The likelihood that humans will be seriously affected by a hazard.

9

Define vulnerability?

How susceptible a population is to the damage caused by a hazard.

10

Define 5 factors that affect peoples perceptions of a hazard?
W
R
E
P E
P

- Wealth = rich people afford to move house.
- Religion = view hazard as act of God.
- Education = More education better understanding of risks.
- Past experiences = People live in hazard-prone areas, adapt and know circumstances.
- Personality = People fear hazards/ others think they're exciting.

11

Define 4 things governments try to do to reduce their vulnerability of a hazard?
P
P
P
F

- Preparation to reduce its magnitude. Building flood defences. Cost risk sharing.
- Prediction of hazard, when, where a hazard will occur.
- Protection of property.
- Fatalism - accept the hazard cannot be avoided.

12

Define the Park Model?

Shows the different phases of response to a hazard.

13

Define the 5 stages in the Park Model?
P D
D
R
R
R

- Pre-Disaster
- Disruption
- Relief
- Rehabilitation
- Reconstruction

14

Define PRE-DISASTER in the Park Model?

Before the event, situation is normal.

15

Define DISRUPTION in the Park Model?

During & directly after the hazard occurred, destruction of property, loss of life.

16

Define RELIEF in the Park Model?

In the aftermath of event, rescue efforts focus on saving people & preventing further damage.

17

Define REHABILITATION in the Park Model?

Once the immediate impacts are under control, people start to resolve longer-term problems (shelter, aid).

18

Define RECONSTRUCTION in the Park Model?

Involves rebuilding permanent houses, infrastructure.

19

Define the 4 phases in the hazard Management Cycle?
M
P
R
R

- Mitigation = minimise impacts in future, build defences.
- Preparedness = Planning how to respond in future, warning systems.
- Response = How people react in disaster situation, emergency services rescue people.
- Recovery = Getting affected area back to normal, repairing rebuilding houses, restoring services.

20

Define the Earth's core?

- Centre of earth
- Inner core = solid ball containing Iron & Nickel.
- Outer core = semi-molten containing Iron & Nickel.
- 6000oC hot

21

Define the Earth's mantle?

- Around core is mantle (Silicate rock).
- Nearest to core/ quite rigid.
- Asthenosphere above mantle (semi-molten).
- 1000-3500oC hot.

22

Define the layers of the Earth?

- Inner core
- Outer core
- Mantle
- Asthenosphere
- Crust

23

Define 2 types of Crust?

- Continental = Is thicker (30-70km thick) less dense.
- Oceanic = Is thinner (6-10km thick) more dense.

24

Define tectonic plates?

- Lithosphere divided into many slabs, which move in relation to each other.
- Plates meet at plate boundaries/margins.

25

Define 3 theories why tectonic plates move?

- Convectional currents
- Slab pull
- Ridge push (Gravitational sliding)

26

Define CONVECTIONAL CURRENTS as a theory why tectonic plates move?

- Parts of asthenosphere heat up from core, less dense, slowly rise, then cool down and slowly sink.
- Circular movements of semi-molten rock called convection currents.
- Create drag on base of tectonic plate, making them move.

27

Define SLAB PULL as a theory why tectonic plates move?

- At destructive plate margins, denser crust is forced under less dense crust.
- Sinking plate edge pulls rest of plate towards boundary.

28

Define RIDGE PUSH as a theory why tectonic plates move?

- Constructive plate margin, magma rises to surface forms new crust.
- Surrounding rock heats, expands, rises above surface forming slope.
- New crust cools down, dense, gravity shifts denser rocks downslope, away from plate margin.
- Puts pressure on tectonic plate, causing then to move apart.

29

Define sea-floor spreading?

- As tectonic plates diverge, magma rises to fill gap.
- Sea bed gets wider as plates diverge, more magma fills gap.
- Creates mid-ocean ridges.

30

Define constructive margin?

Occurs where two plates move APART from eachother.