Physical Paper Flashcards
Describe how plate tectonics causes volcanic activity.
Oceanic plate is more dense than continental plate so is subjected and plate moves towards the mantle, melting the plate.
This causes magma to rise and viscous magma and explosive means volcanoes erupt.
Case study of phillipines ‘ring of fire’
Philipines is seismically active Pacific ‘Ring of Fire’ a band of volcanoes and fault lines
It is located in cyclone belt aprrox 5 - 25 degrees north and is affected by storms as they blow west in Pacific Ocean
The sea temp around 26 degrees allowing warm, moist body of air to develop due to intense evaporation.
Philipines has low lying areas (e.g. Manila) which are prone to flooding.
Floods can also be secondary hazard following on from cyclones
Low income countries are limited to flood defence
What happens when oceanic and continental plates meet?
Oceanic is more dense and subducts under continental plate towards the mantle.
Produces ANDESITIC LAVA - high silica content and a higher percentage of volatile gases. which moves through fissures and gaps.
Which plate causes larger damage?
Destructive plate boundaries generate larger magnitude volcanic eruptions that constructive or hot spots.
What other factors can cause impact due to volcanic eruptions?
Population density - more living at a hotspot or a area with high vulnerability then higher chance of damage and impact caused to them
What type of coastlines form when isostatic sea level rise, eustatic sea level rise.
Isostatic sea level rise - Emergent coastline formed
Isostatic sea level is local sea level risk due to the land sinking, crustal material is forced down into the mantle. Changing the relative sea level
Eustatic sea level rise - Submergent coastline formed
What is the rate of erosion at Holderness coastline.
2 metres per year
soft boulder clay and chalk
How can storm surges cause coastal erosion
Storm surges means more destructive wave - higher height, produce plunging breakers where backwash>swash.
So more coastal recession compared to constructive wave.
What did the COP21 Paris Agree to do
COP21 agreed in Paris 2015, aim to rebalance carbon cycle by cutting global emissions to below 20Gt per year by 2040 - reduces risk.
What other alternatives are there to prediction and forecasting.
It may be difficult to predict hence some countries invest in aseismic building as well as education and training to reduce vulnerability.
How are fjords created?
Fjords are created when the very deep coastal glacial at U shaped valleys called glacial troughs are flooded by rising sea level.
Fjords have steep valley sides and uniformly deep water (1000m)
In the UK, what percentage of energy Is renewable
43% of energy
Which volcano has a lot of frequency in eruption
Mount Merapi, Indonesia is a decade volcano and has frequent pyroclastic flows affecting the vulnerability of the community.
Explain the differences in the characteristics of beach between summer and winter?
Storm berm in winter is created by large destructive waves progressing further up the beach than normal, carrying large sediment when is then deposited.
Explain two ways in which a warming climate can lead to a rise in global sea level.
More greenhouse gas, so temperature rises and more glaciers and ice sheets melt hence can lead to rise in global sea level rise.
Thermal expansion of ocean water as molecule move more vigorously. Hence sea level rises.
Suggest economic impacts of rising sea level on developing countries.
Increased cost of medical care if more coastal defences.
Rely on primary industry (agriculture) for source of income. If flooding occur this is destroyed and cannot be sold so causes economic impact.
Explain how the planting of new forests could assist with:
1. Climate change mitigation
New forest increase uptake of CO2
Reduces impact of enhanced greenhouse effect
Explain how the planting of new forests could assist with:
adapting to climate change
Increase forest could help reduce effect of flooding - interception of water from vegetation such as mangroves.
Explain how the risk of disaster can increase as a risk of:
1. frequency of the hazard
2. magnitude of the hazard
- Less recovery/planning time, constant damage
- Larger damage and effect, capacity to cope is overwhelmed by scale of disaster.
Explain how changes in sea level ice extent may accelerate global warming.
Darker ocean surface lowers albedo levels reflects less light
This warms air/ sea surface temperature
This warms air / sea surface temperatures
Positive feedback
Explain why earthquakes are often experienced in coastal areas of California
California has the San Andreas fault lines, so earthquakes are frequent. Majority of the coastal area lie within 50 km of the San Andreas Fault line.
Conservative boundary - plates slide past one another at different rates. The friction produces pressure which travels in the form of seismic waves to the epicentre.
Name two natural hazards which could be caused by high rainfall
Flooding
Landslides/Mass movement
How would farmers adapt to
1. changing annual rainfall
2. Rising temperatures
- Irrigation, finding ways to collect rainfall (micro dams)
Use of GM crops, use land for new purpose. - Plants that are resistant to heat. Irrigation.
Explain two natural causes of short term climate change
Sunspot - affect temperatures because more UV radiation. More storms are warmer
Periodic movements of jet stream/ocean currents can affect rainfall temperatures
What are the two constructive (divergent) plates that can form.
2 oceanic = mid ocean ridge
Oceanic plates diverge extend underwater as mountain chains with transform faults cut across. - earthquakes and volcanoes
2 continental = Rift valleys
Crust forms parallel cracks and the land between them collapse, creating steep valleys - earthquake
What are the three types of seismic waves
P- fastest wave and travels through solid liquid, least damaging
S- move slower, travel only through solids.
L - love waves, slowest and most damaging.
Case study of Christchurch - earthquake
earthquake 2010
Magnitude of 7.1
Significant Liquefaction - infrastructure sinking
$12 bn losses
Old buildings destroyed
Many companies refused to insure people that live in dangerous prone areas, heavily rely on their own means of recovery - government –> natural disadvantage.
Successful - post management where temporary housing in caravans and cathedral
GP and emergency care
72 specialist workers arrived
Case study of Kashmir - earthquake
2005 Kashmir Earthquake - magnitude 7.6
At least 79,000 people were killed and more than 32,000 buildings collapsed in Kashmir.
Remote regions, so difficult to reach. Lack of maps. Harsh Himalayan winter blocked access for 6 months.
Local ideas and cultural design - Dhajji Dewari house design made from timber and earth infill, gave strong foundation and more resistant to the high magnitude earthquake.
Modern design buildings and collapsed in the area and did not withstand the pressure.
Tension with Indian government so less aid provided to help with recovery
Pakistani economic focus rather than aseismic construction
Iceland - Eyjafallajokulll eruptions - volcanic
2010 April
Atmospheric circulation, ash clouds affected flights over Northern Europe
100,000 flights were cancelled
1.7 billion US dollars lost in airline revenue
Kenya impact most - rely on export of fruit and veg , 1.3 million US lost daily
How is a tsunami formed?
Give a case study
An earthquake rocks the ocean floor
Displaces volume of water pushing it up
sets off an oscillation which develops underwater at great speed
sea water is sucked back from the shore
waves get bigger as water gets shallower
Indian Ocean tsnumani - 2004
magnitude 9
No early warning system
5 million people affected, 14 countries
10 billion dollar damage
Nepalese Earthquake
2015
magnitude 7.8
over 8000 deaths
lost 65 billion dollars
extremely poor, half population in poverty
Kathmandu buildings collapsed
Mountainous so landslides so difficult to rescue
Unable to cope relied on oversea aid
