Stuff im shaky on

Question 1

How is heat transferred by ocean currents?

Answer 1

1. Ocean currents are large scale movements of water that transfer heat energy from warmer to cooler regions.
2. Surface currents are caused by winds and help transfer heat away from the equator, e.g. the Gulf Stream brings warm water from the Caribbean and keeps Western Europe warmer than it otherwise would be.
3. There are also deep ocean currents driven by differences in water density.
4. When water freezes at the poles, the surrounding water gets saltier, increasing its density.
5. As it gets denser, it sinks, causing warmer water to flow in at the surface, creating a current.
6. This warmer water is cooled and sinks, continuing the cycle. This cycle of cooling and sinking moves water in a big loop around the earth, known as the thermohaline circulation.

Question 2

How does farming cause global warming?

Answer 2

1. Agricultural land contributes to 12% of GHG emissions.
2. Use of pesticides releases greenhouse gases such as nitrous oxide which contributes to the enhanced greenhouse effect.
3. Cattle ranching is the biggest cause of deforestation in Brazil - 80% of deforerrested areas being used for pasture.
4. Less trees exrtracting CO2 from the atmosphere.
5. Cows release between 10kg and 120kg of methane per year, methane has a 23x stronger effect on the enhancred greenhouse effect than CO2.
6. Rice paddy fields are one of the largest sources of Methane in the world. As populations increase, rice producton will increase as it is a staple food.

Question 3

How does industry cause global warming?

Answer 3

1. Total GHG emissions from industry almost doubled between 1970 and 2010.
2. Most industry uses a lot of energy.
3. Some industrial processes also release greenhouse gases, e.g. cement is made from limestone, which contains carbon. When cement is produced, lots of CO2 is released into the atmosphere.
4. Industrial waste may end up in landfill sites where it decays, releasing methane.

Question 4

Where do tropical cyclones form?

Answer 4

1. Most tropical cyclones occur in a band of low pressure and warm temperatures between 5° and 30° N and S of the equator
2. These conditions are created by global atmospheric circulation
3. They develop when the sea temperature is 27°C or higher and when the wind shear between higher and lower parts of the atmosphere is low
4. Warm, moist air rises and condensation occurs -> this releases huge amounts of energy which makes the storms powerful
5. The rising air creates an area of low pressure, increasing surface winds
6. They move west due to easterly winds near the equator. The earths rotation deflects the winds, making the storm spin
7. The cyclone gets stronger due to energy from the warm water, so wind speeds increase

Question 5

How are interlocking spurs formed?

Answer 5

1. In the upper course of a river most of the erosion is vertically downwards. This creates steep sided V-shaped valleys.
2. The rivers aren’t powerful enough to erode laterally - they have to wind around the spurs that stick out into their paths on either side.
3. These hillsides are often made of a resistant rock which the river can’t erode, so the river erodes the less resistant rock between the spurs as it winds down the valley.
4. The hillsides that interlock with each other as the river winds around them are called interlocking spurs.