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Tectonic Hazards - Coggle Diagram
Tectonic Hazards
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Effects of an earthquake
Primary effects - buildings and bridges collapsing, homes destroyed, people injured or killed by collapsed buildings or debris, transport networks are damaged, power, water and communication networks cut off.
Secondary effects - landslides and tsunamis, leaking gas pipes resulting in fires, people left homeless and could die from extreme weather conditions, shortage of clean water and poor sanitation can lead to disease, destroyed transport networks result in difficulties getting emergency vehicles in and trade destroyed which leads to loss of income.
immediate responses - stop loss of life e.g. rescue trapped people and treat injuries, recover dead bodies to reduce spread of disease, put out fires, give shelter to homeless, provide water and food, charities send aid workers.
long term responses - people are rehoused, repair buildings, transport and communication networks, improve building regulators to prevent disaster occuring again
Management strategies
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prediction - using historical data, scientists can make predictions about when a tectonic hazard may occur
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planning - train individuals as well as specialist teams on what to do in the event of a tectonic hazard
continental crust
thick (39-100km), made of granite
light, flexible, will not subduct
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plate margins
constructive - when 2 plates move apart. magma comes to surface and breaks through crust creating earthquakes. Magma will flow far before cooling creating a shield volcano. E.g. North American and Eurasian Plates forming Iceland in the Atlantic Ocean.
destructive - 2 plates move towards each other. Oceanic plate subducts the continental, pulls the tip down and forces an ocean trench. Friction causes earthquakes. As oceanic enters mantle it melts, causing more magma. Eruptions are violent and explosive. Steep sided composite volcanoes are formed here. E.g. Pacific Oceanic Plate dipping under the South American Continental Plate.
conservative - when 2 plates move alongisde each other, friction between the 2 plates can build up and cause earthquakes. E.g. San Andreas Fault.
oceanic crust
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made of basalt, can subduct, 200m years old
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ridge push - occurs when the weight of an elevated ridge pushes an oceanic plate towards a subduction zone.
slab pull - occurs as the weight of the subducting plate pulls the rest of the crust into the subduction zone
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