Plate Movement, Volcanoes & Mitigation: Tectonics & Human Response, Lecture notes of Geography

Download Plate Movement, Volcanoes & Mitigation: Tectonics & Human Response and more Lecture notes Geography in PDF only on Docsity!

A Level geography Revision lesson

Learning objective:

To review our learning so far

and identify gaps in our

knowledge

Revision session based on lesson so far (Nov

Revision session based on lesson so far (Nov

1. Concepts of

Hazards

2. Plate tectonics

3. Storm Hazards

4. Volcanic Hazards

When does a hazard become a hazard?

Natural Event (^) Population

No hazard

Natural Event Population

If there is an interaction= hazard!

Nature of the hazard

Complete the mind map below; what factors

change the impacts of a hazard?

Factors that affect the nature of the hazard

Scale of the disaster e.g. size of earthquake or volcano.

Think back over the last couple of lessons..

There are a number of ways we can classify

hazards.

Look at the list below and think of the

categories that you could sort them into.

How can we classify hazards?

CATEGORIES

Nature of the hazard (e.g. geomorphological, biological, tectonic)

Natural or man made

Magnitude

Frequency

Impact

Think..

Are these categories suitable? Is there overlap? Can you

see any issues with using them?

Effects Primary Secondary Short Term Long Term Death Economic Loss Loss of wildlife Storm Surge Poverty Climate Change Flood Infrastructure Damage Disease Homelessness Injury Food Scarcity Emotional Stress Evacuation Tsunami Fires Shaking Pyroclastic Flow

Effects Task: more effects and repeat the process. Identify using a tick which of the categories each of the effects can be grouped in. Can you think of two

Adaptation: Implementing strategies to prevent the event becoming a hazard. Earthquake proof buildings.

Fatalistic: An optimistic approach Some believe that hazards are God’s will. Losses are inevitable People stay where they are.

Prediction: Using technology available to them to predict and prepare for the event. E.g. weather forecasts and seismic monitoring.

Risk Sharing: Insurance to ensure that the cost of a hazard is spread between a number of parties. Quick questions: Which of these is more suited to an LIC? Which of these is more suited to a HIC? Why?

Responses

There are 3 different types of responses that people can have to hazards:

1. Fatalism (acceptance)
2. Adaptation
3. Fear

For each of the 7 influences identify which responses are likely to occur. E.G. High level of education will likely have the response of adaptation.

1. Socio-economic status
2. Level of education
3. Occupation/ employment status
4. Religion, cultural/ethnic background
5. Family and material status
6. Past experience
7. Values, personality and expectations.

Fatalism (Acceptance) = Such hazards are natural events that are part of living in an area. Some communities would go as far as to say that they are ‘God’s will’. Action is therefore usually direct and concerned with safety. Losses area accepted as inevitable and people remain where they are. Adaptation = People see that they can prepare for, and therefore survive the event(s) by prediction, prevention and technological circumstances of the area in question. Fear = The perception of the hazard is such that people feel so vulnerable to an event that they are no longer able to face living in the area and move away to regions perceived to be unaffected by the hazard.

The park model for responding

to a hazard

Look at the model in front of you. What do you think the model is trying to show?

The Risk Management cycle.

Both before and after a disaster, whether that be hydrological, atmospheric or geophysical strategies can be used to reduce the damage of the current and future hazards.

The Risk Management cycle outlines the appropriate strategies that can be taken.

Construct your own cycle and try to come up with an example for each stage.

1. Earth structure and internal energy sources.

2. Plate tectonic theory of crustal evolution: tectonic plates;

plate movement; gravitational sliding; ridge push, slab

pull; convection currents and sea-floor spreading.

3. Destructive, constructive and conservative plate margins.

4. Characteristic processes: seismicity and vulcanicity.

5. Associated landforms: young fold mountains, rift valleys,

ocean ridges, deep sea trenches and island arcs,

volcanoes.

6. Magma plumes and their relationship to plate movement

Characteristics Continental Crust Oceanic Crust

Thickness 6 -10 km 30-70 km

Age Less than 200 million years Over 1.500 million years

Density 2.6 (lighter) 3.0 (heavier)

Composition Mainly granite; silicon, aluminium, oxygen (SIAL)

Mainly basalt; silicon, magnesium, oxygen (SIMA)

Crust Characteristics

Plate Tectonics

• This picture shows the plates of the

world and the way they are moving.