Hazardous Earth GCSE Flashcards
What are the 3 cells ?
Hadley
Ferrel
Polar
How is heat transferred by ocean currents?
Surface currents are caused by winds that transfer heat energy away from the equator. E.G the gulf stream
Deep ocean currents are when frozen water sinks causing warmer water to rush up to the surface . This repeated process causes a cycle transferring heat energy around the world
It is called THERMOHALINE CIRCULATION
How are arid climates formed?
Sinking air caused my hadley and ferrel cells cause high pressure preventing rainfall .
How are tropical climates formed ?
Rising air from 2 hadley cells causes low pressure allowing air to rise condense and from clouds which produce precipitation .
How is the polar climate formed?
Sinking air from 2 polar cells
Orbital changes
Eccentricity-when the path from the earth to the sun changes shape
Tilt-axis is tilted at an angle
Wobble- axis wobbles like a spinning top
These factors effect the amount of solar radiation the earth receives
How has volcanic activity effected the earths climate
Eruption emits ash clouds that blocks the sun rays decreasing temperatures in certain areas . E.G the year without summer 1816 Indonesia
What is the evidence of natural climate change
Tree rings - thickness of rings show the temperature of each year. Scarring can show where forest fire took place
Ice core- drills collect long cores of ice . They can analyse what gases are trapped in the ice cores and identify temperatures of years.
Historical recordings.
What human activity has enhanced the green house effect
Farming -live stock produce green house gases and deforestation reduces absorption of carbon dioxide.
Industry- industrial processes release huge amounts of greenhouse gases due to combustion of fossil fuels
Transport- most transport releases pollutants car ownership is increasing
What is the proof of climate change?
Thermal expansion leads to an increase of sea levels
Artic ice has decreased 3 percent in the last 35 years
Temperature has increased by 1 degree since 1880
What are the impacts climate change will have on people
Heat increase can cause death
Lowers crop yields causing starvation
Areas will become barren of water and vegetation leading to an increase of immigration
Why is there an uncertainty when tracking climate change.?
Emissions will vary and is hard to know how much the population will grow
It is extremely difficult to gauge all scenarios of climate change
It is impossible to predict any management schemes that will be put into effect in the future
Formation of a tropical cyclone
Can only develop if the sea temperature is at least 26.5 degrees and when the wind shear is low
Warm moist air rises and condenses releasing a huge amount of energy. Rising air causes low pressure
Earths tilt will cause the storm to spin
The cyclone will intensify as more heat energy is collected from the warm waters
They dissipate when moving over land or cold water because their energy supply runs short
Features of a tropical cyclone
Centre of cyclone is 50 km side . High temp but low pressur
Eye wall is a spiraling wall of rising air around 160 km per h
Physical hazards of a tropical cyclone
High winds Intense rainfall Storm surges Coastal flooding Landslides
Environmental impacts of tropical cyclones
Trees are uprooted
Storm surges causes coastal erosion
Flooding polluted water sources
Landslides deposit sediment in rivers
What physical attributes would a country have to make it vulnerable to a tropical cyclone
Low lying coast line making it more vulnerable to flooding
Steep hillsides increase the risk of landslides
What economic attributes would a country have to make it vulnerable to a tropical cyclone
More dependent on agriculture . Cyclones destroy agriculture therefore a loss of lively hoods would occur .
A lack of funds to repair damages done to buildings and roads
How would a country be socially vulnerable to a tropical cyclone ?
Health care is poor so many go untreated
Little money for flood defenses
Harder to rescue people as there would not be a dedicated emergency response team
Strategies to respond to a tropical cyclone
Forecasting allows countries to priorities certain areas to evacuate and defend . Allowing for a reduction of casualties.
Evacuation plans will allow for a quicker evacuation process as civilians will be prepared
Defences such as sea walls will be built along the coast to reduce damage to major cities . Houses can be specifically built to withstand natural disasters
USA HURRICANE KATRINA CASE STUDY!
29th August 2005
forecasting - sophisticated monitoring system predicted where the cyclone would hit. NHC (national hurricane centre in florida)
Warning and evacuation- warning issued 3 days before the hit allowing for 70-80 percent of new Orleans to get out massively reducing casualties.
Defences- completely failed . 80 percent of the city was flooded causing huge damages to buildings.
Impacts on environment- coastal habitats were destroyed
Flooding causes oil refineries to spill
Half of Brenton national wildlife refuge was washed away
Impacts on people-1800 died
330000houses were destroyed
3 million were left with no electricity
230000 jobs were lost
CYCLONE NARGIS MYANMAR!
2nd May 2008
Forecasting- no monitoring system and no prediction of storm surges.
Evacuation- they had only 48 hours to evacuate. They broadcasted the warning on television and radios. Most people lived in rural communities and could not get access to the technology .
Environmental impacts- 38000 hectares of mangrove forest destroyed
Flooding caused salination
14000 km2 of land was flooded
Impacts on the people- 140000 were killed
450000 houses destroyed
Contaminated waters caused huge spreads of disease
