Restless Earth
This mindmap contains the informations and some case studies for the GCSE Edexcel Geography Restless Earth Topic.
- Created by: Lauren
- Created on: 20-03-13 15:37
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- Restless Earth
- Inside the Earth
- Planet Earth is made up of 4 layers. The crust, mantle, outer core and inner core.
- The crust is made up of rock and sits on top of the mantle. It is separated into different sections called tectonic plates, as they move freely.
- Continental crust is very thin and is mainly made up of granite, which has a low density.
- Oceanic crust is even thinner than continental crust, but is made up of a denser material called basalt.
- The second layer is the mantle which is thought to be a solid. Convection currents, caused by heated gas from the outer core, moves the tectonic plates above.
- The third layer is the outer core, which is molten rock.
- The final layer is the inner core, which is supposedly a solid ball of iron and nickel.
- The crust is made up of rock and sits on top of the mantle. It is separated into different sections called tectonic plates, as they move freely.
- Planet Earth is made up of 4 layers. The crust, mantle, outer core and inner core.
- Plate Boundries
- Conservative
- When the two plates rub against each other.
- This leads to earthquakes, as their jagged edges lock together and burst apart suddenly.
- Case Study: San Andres Fault
- This leads to earthquakes, as their jagged edges lock together and burst apart suddenly.
- When the two plates rub against each other.
- Constructive
- When two plates seperate
- There are small earthquakes here.
- Volcanoes also happen here, as rising basalt lava fills the gap, causing a shield volcano.
- Shield volcanoes are the less violent.
- Case Study: Iceland
- When two plates seperate
- Destructive
- When one continental and one oceanic plate collide.
- During this process, the denser oceanic plate slides beneath the less dense continental plate.
- This creates earthquakes, during which a tsunami can form.
- They also create very destructive composite volcanoes.
- Case Study: Andes Mountains
- During this process, the denser oceanic plate slides beneath the less dense continental plate.
- When one continental and one oceanic plate collide.
- Collision
- When two continental plates collide.
- Earthquakes happen here, sometimes causing landslides.
- They rarely form volcanoes, but do create fold mountains, as the plates buckle under the pressure.
- Case Study: Himilayers
- When two continental plates collide.
- Conservative
- Volcanoes
- Types of volcanoes
- Shield Volcanoes
- They have basaltic lava (very fluid)
- Violent eruptions are rare
- The most common is lava fountains, which feed lava flows.
- Case Study: Mauna Loa, Hawaii
- Composite Volcanoes
- They have sticky, andesitic lava.
- Blocking the vents and causing violent eruptions
- They are prone to large explosions of ash and rocks.
- They have the power to affect the temperature of the planet on a global scale.
- Case Study: Mt Pinatubo, Philippines
- They have sticky, andesitic lava.
- Shield Volcanoes
- Volcanoes Statues
- Active-when a volcano is currently erupting
- Dormant-when it hasn't erupted for a long time, but the possibility is still there
- Extinct-when it no longer erupts
- Volcanoes in the Developed World
- Can afford to equipment that can predict an eruption
- Evacuation messages can be sent out and routes set more clearly
- The people have insurance and the government can afford to help
- Case Study: Japan since 1950's Erupts 200 times per year. Monitors volcano. Locals insured, government will help to rebuild. 40% of land surrounding volcano is fertile due to ash.
- Volcanoes in the Developing world
- Can't afford safe housing or insurance
- Communications for evacuations are poor
- Live is risky locations du to good farming land
- Case Study: Republic of Congo, January 2002. 14 Villages destroyed. 100 dead. 400,000 evacuated. United Nations and Oxfam sent 260 tonnes of food. $35 million raised globally.
- Types of volcanoes
- Earthquakes
- In the Developed world
- They cannot be predicted, even in richer countries
- They are measured on their magnitude (Richter Scale) using a seisometer
- Long term planning such as: earthquake drills, emergency services specially trained, kits at home, stronger housing foundations
- Case Study: Japan, July 2007. 6.8 earthquake. 350 buildings destroyed. 11 deaths. Earthquake drills, emergency services specially trained, people had emergency kits in their homes.
- Earthquakes in the Developing world
- They don't have finances for monitoring equipment
- Have difficulty putting evacuation plans in place
- Often rely on international support and aid
- Case Study: China, May 2008. Primary: 70,000 people killed. 5 million made homeless. Local responses include 50,000 soldiers and $5 billion raised in aid. International aid include funding, tents and medicine.
- In the Developed world
- Inside the Earth
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