geography sec.solihull.sch.uk/aqa-rivers-revision.pdf
Post on 22-Dec-2015
219 Views
Preview:
TRANSCRIPT
GEOGRAPHYhttp://
www.langley-sec.solihull.sch.uk/AQA-Rivers-Revision.pdf
Restless EarthDistribution of plates; contrasts between
continental and oceanic plates.Destructive, constructive and conservative
plate margins.
1. More dense – heavier
2. Darker
3. Younger
4. Basalt
1. Less dense
2. Lighter (in colour)
3. Older
4. Granit
1. Density2. Colour3. Age4. Rock
Type
Restless EarthDestructive, constructive and conservative
plate margins.
• oceanic and continental plate move towards each other.
• The dense oceanic plate is forced under the continental plate.
• As it sinks below the continental plate the oceanic plate melts due to friction in the subduction zone.
• The crust becomes molten called magma.
• This may be forced to the surface of the earth causing a volcanic eruption.
• The movement of the oceanic plate is not smooth.
• Due to friction the plate gets stuck. Pressure then builds up.
• The plate will eventually slip sometimes causing an earthquake.
Mid ocean ridge?
• Plates move away from each
other due to convection currents
in the magma
• Magna rises from the mantle
through the opening.
• The magna erupts to the surface
of the earth.
• When the magma reaches the
surface the lava cools and
creates new crust.
• Formation of ocean trenches?
ShieldVolcanoes
Gentle slopes
frequent
Low-wide base coneThin-runny
lava
Non violent
Constructive PB
E.g.. Mauna loa
Composite
VolcanoesDestructiveSteep sidesExplosiveLess frequentMade of alternative layers of ash + lava
Eg mount fuji
Andes: fold mountain• FarmingGrow crops on low valleys. Cash crops:
• HEP: Hydroelectic actionSteep slopes, narrow valleys = easily dammed. Snow melt increases supplies. El Platinal dam 2nd biggest in Peru • MiningLot of important minable material. Iron, nickel, silver, Gold, Coal, Oil. Mining in Yanacocha is open cast (largest in the world)• Tourism
• The length of the west coast of south America.
• Oceanic and continental crust
Warning signs Monitoring techniques
Hundreds of small earthquakes are caused as magma rises up through cracks in the Earth's crust.
Seismometers are used to detect earthquakes.
Temperatures around the volcano rise as activity increases.
Thermal imaging techniques and satellite cameras can be used to detect heat around a volcano.
When a volcano is close to erupting it starts to release gases. The higher the sulfur content of these gases, the closer the volcano is to erupting.
Gas samples may be taken and chemical sensors used to measure sulfur levels.
Key techniques for monitoring a volcano
• Preparing for an eruption• A detailed plan is needed for dealing with a possible
eruption. Everyone who could be affected needs to know the plan and what they should do if it needs to be put into action. Planning for a volcanic eruption includes:
• creating an exclusion zone around the volcano• being ready and able to evacuate residents• having an emergency supply of basic provisions,
such as food• funds need to be available to deal with the emergency
and a good communication system needs to be in place
EarthquakesPredicting & Preparing
• Seismometer: used to pick up the vibrations in the Earth’s crust. An increase may indicate earthquake.
• Radon gas: escapes from cracks in crust. Sudden increase= earthquake.
• Training: holding drills, education via TV, Radio.
• Emergency kits: stored in homes, tinned food. First aid, blankets.
• Earthquake proof buildings: designed to absorb the energy from earthquake.
Measuring Tool
Seismograph Observation
Measures The energy released by earthquake
The effects caused by earthquake
Calculation Information resulted from seismometers that measure the shock waves and movement
Quantified from observation of effect on earth’s surface, human, objects and man made structures.
Scale 1 – 10+ I – XII
Richer Scale Mercalli Scale
San Andreas
Conservative Plate Boundary :
CASE STUDY: Haiti (LEDC)
EFFECTS
280,000 buildings collapsed =90% of all
16,500 schools damaged
316,000 killed
3m affected
Transport & communication links damaged
Flattened homes= living on the streets n cars.
Huge economy impact
1/5 jobs lost
Roads blocked 10 days after
CASE STUDY: Japan (MEDC)
EFFECTS
10 trains were derailed
A 500m wall of flame swept through the city
180,000 buildings were damaged.
Thousands trapped in the rubble
5,390 died
Risk of disease-No sewage system &disposal of dead bodies were delayed
After shocks
230,000 homeless
Such as Panasonic were forced to close
HAITI
Caribbean + N. American plates moving same direction.
Shallow focus of 13km below surface.
Epicentre 16km west of capital, Port-au-Prince.
Seismologists warned of huge earthquake as fault been ‘locked’ for 250yrs.
JAPAN,KOBE
top related