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geography - Coggle Diagram
geography
Natural hazards are extreme natural events that can cause loss of life, extreme damage to property and disrupt human activities.
Tectonic hazards occur when the Earth's crust moves. For example, when the plates move, friction can cause them to become stuck. Tension builds until the plates release, which leads to an earthquake.
Climatic hazards occur when a region has certain weather conditions, for example heavy rainfall can lead to flooding.
earth
The inner core is in the centre and is the hottest part of the Earth. It is solid and made up of iron and nickel with temperatures of up to 5,500°C.
The outer core is the layer surrounding the inner core. It is a liquid layer, also made up of iron and nickel.
The mantle is the thickest section of the Earth at approximately 2,900 km. The mantle is made up of semi-molten rock called magma.
Oceanic crust - found underneath the oceans. It is denser than continental crust and can be subducted.
Continental crust - found under land masses or continents. It is generally older than oceanic crust and is less often destroyed.
A destructive plate margin usually involves an oceanic plate and a continental plate. The plates move towards one another and this movement can cause earthquakes.
As the plates collide, the oceanic plate is forced beneath the continental plate. This is known as subduction. This happens because the oceanic plate is denser (heavier) than the continental plate.
At a constructive plate margin the plates move apart from one another. When this happens the magma from the mantle rises up to make (or construct) new land in the form of a shield volcano. The movement of the plates over the mantle can cause earthquakes.
At a conservative plate margin, the plates move past each other or are side by side moving at different speeds. As the plates move, friction occurs and plates become stuck. Pressure builds up because the plates are still trying to move. When the pressure is released, it sends out huge amounts of energy, causing an earthquake. The earthquakes at a conservative plate boundary can be very destructive as they occur close to the Earth's surface. There are no volcanoes at a conservative plate margin.
. The highest rates of population growth are occurring in low income countries (LICs), such as Zimbabwe, Malawi and Niger
Today more than 50% of the world's population live in urban areas. The number of cities with over 10 million people is increasing. These are called megacities. There are now 34 megacities in the world.
Natural increase (or decrease) - this is the difference between the number of births and the number of deaths.
Migration - this is the movement of people into or out of the city.
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