Tectonic Hazards Flashcards
What are the different types of natural hazards
Volcanic eruption, earthquakes, storms, tsunami, landslides and floods.
Factors affecting risk from natural hazard
Urbanisation, poverty, climate change, farming.
What is an earthquake
Sudden and violent period of ground shaking.
What is oceanic crust
Dense, thin
What is continental crust
Less dense, thick
Where do volcanoes form
Long belts that follow the plate margins.
What happens at a constructive margin
Two plates are moving apart. Magma forces its way to the surface. As it breaks through the overlying crust it causes earthquakes. On reaching the surface it forms volcanoes such as Eyjafjallajokull in Iceland.
What happens at a destructive margin
Two plates are moving towards one another, the oceanic plate (dense) is subducted beneath the less dense continental plate. As the oceanic plate moves downwards it melts. This creates magma which is less fluid than at a constructive margin. It breaks through to the surface to form a volcano
What happens at a conservative margin
Two plates move alongside each other. Friction between the plates then causes earthquakes.
What did the earthquake hitting Nepal measure on the richer scale
7.9
What margin caused the earthquake in Nepal
Destructive plate margin
Measurement of the earthquake that hit Chile
8.8 on the Richter scale
What margin caused the earthquake that hit Chile
Destructive plate margin
Primary effects in Chile
500 killed, 220000 homes destroyed, airport damaged, cost 30 billion. DHC
Secondary effects in Chile
1500km of roads damaged, tsunami waves destroying coastal towns, fire at a chemical plant.
Primary effects in Nepal
9000 dead, 3 million left homeless, cost of damage 5 billion, Airport destroyed.
Secondary effects in Nepal
Landslides, avalanches on mount Everest killed 19 people.
Chile immediate responses
Power and water restored emergency shelters.
Chile long-term responses
Launched a housing reconstruction plan, Chiles’s strong economy based on copper exports could be rebuilt without the need for much foreign aid.
Nepal immediate responses
Search and rescue teams, Finacial aid, field hospitals set up.
Nepal long-term responses
Roads repaired, stricter controls on building codes, tourism reopened, seek financial support from other countries.
Why do people live in hazardous areas
Poverty, not aware of risks, volcanoes bring benefits such as fertile soils, better building design and protection, earthquakes and volcanic eruptions don’t happen very often.
Tectonic activity benefits in Iceland
Hot water from the earth’s crust provides heat and hot water for nearly 90% of all buildings in Iceland. Volcanic rocks are used in construction, dramatic landscape is loved by tourists, Geothermal energy is used to generate 25% of the countries electricity.
What is monitoring
Using scientific equipment to detect warning signs of events such as a volcanic eruption.
What is Prediction
Using historical evidence and monitoring, to make predictions when a hazard will take place.
What is protection
designing buildings that will withstand tectonic hazards.
What is planning
Identifying and avoiding places most at risk.
