hazardous earth

What are possible consequences of global warming?

• Biodiversity loss on land and in the oceans

• Coastal flooding from sea-level rise

• More frequent, stronger hurricanes

• Spread of pests and disease

• Changing in farming could affect food supplies

What is the enhanced greenhouse effect?

1. Heat (UV rays) from the Sun reaches the Earth’s atmosphere; some is reflected back into space

2. Land + oceans absorb the heat

3. Land + oceans then radiate infrared heat back into the atmosphere

4. Greenhouse gases in the atmosphere trap some of the heat

5. Human activity increases greenhouse gases in the atmosphere

What are 3 key characteristics of a tropical cyclone?

1. Low pressure

2. Rotation; Coriolis force

3. Structure; eye of the storm, etc

How do tropical cyclones form?

1. Warm sea temperatures of 26°C

2. Lots of moisture in the atmosphere

3. Rapid cooling

4. Rising air must condense quickly to generate energy

5. Winds cannot blow in different directions

6. Coriolos force for the cyclone to spin

7. Smaller storms come together to form tropical cyclones

What are the physical hazards of tropical cyclones?

• Storm surges

• Coastal flooding

• Landslides

What causes storm surges?

• Water pushed up by the wind in front of the storm has nowhere to go but onto land

• Low pressure in the tropical cyclone increases the surge

• Slow moving tropical cyclones cause biggest surges

How does coastal flooding occur?

• If the land is low lying, storm surges can flood the areas

What triggers landslides?

• Rainfall causes flash flooding and triggers landslides on unstable slopes

What is used to predict tropical cyclones?

• Satellites spot a tropical cyclone forming and tracks its progress

What factors make a country more or less vulnerable? (+ examples)

• Physical — low-lying coastal areas

• Social — low quality housing

• Economic — better prediction, protection + evacuation technology

How do convection currents contribute to plate movement?

1. The core heats the molten rock in the mantle to create a convection current

2. Heated rock from the mantle rises to the Earth’s surface

3. At the surface, the convection current moves the tectonic plates in the crust

4. Molten rock cools and flows back to the core to be reheated

What are hotspots?

Points on the Earth’s crust with very high heat flow, which is linked to increased volcanic activity

Where does the energy produced from earthquakes come from?

• Epicentre — the point directly above the focus

• Focus — the central point of the earthquakes, greatest release

How to strengthen a building for a earthquake?

• Installing a ring beam — stops walls falling outwards

• Very strong framework

• Strengthen walls

• Reinforcing gas + water pipes

What to write to describe the trend of (eg. ice) in a graph?

• “Overall, ice increases/declines in the period shown”

• If there are fluctuations or not

• Range

• First ice drop below average

2 reasons tropical cyclones lose energy?

1. Reach land (1) so they lose access to warm water; source of power (1)

2. Move into areas with cooler water (1) as they need temperatures of over 26.5°C (1)

One cause of a tsunami?

Earthquakes (1) caused by plate movement (1)

What is one way global atmospheric circulation determines location of high rainfall areas?

At the equator (1) less dense air rises (1) cools and condenses forming clouds (1)

Explain one role of ocean currents?

Redistribution of heat (1) to regulate uneven global temperatures (North Atlantic Drift) (1)

How might climate change affect food? (2)

• High temperatures might destroy some crops (1) limiting supply of food (1)

Explain one reason why some places are arid (low rainfall)?

• Air cannot rise in high pressure areas (1) so clouds cannot form (1)

What are sunspots and how are they linked to climate change?

Black spots on the surface of the sun, that are hotter areas.

• The more sunspots, the higher level of heat given out

• Lack of sunspots has caused ice ages

Does a circular or elliptical orbit lead to warmer periods and why?

• The more circular the orbit, the warmer temperatures on Earth

• The Earth is closer to the sun, so it receives more solar radiation

What is the greenhouse effect?

A natural process by which the natural layer of gases in our atmosphere trap some of the energy from the sun

• Keeps our temperature suitable for life