Tectonic Hazards Flashcards
(29 cards)
What is a natural hazard?
A natural event that threatens people or has the potential to cause damage, destruction, or death.
What is hazard risk?
The probability that a natural hazard will cause harm to people, property, or the environment.
Name the 4 main types of natural hazards.
Tectonic, atmospheric, hydrological, biological.
What are tectonic hazards?
Hazards caused by movements of the Earth’s crust (e.g. earthquakes, volcanoes).
What is a constructive plate boundary?
Where two tectonic plates move apart, allowing magma to rise and form new crust.
What is a destructive plate boundary?
Where two plates move towards each other and one is forced under the other (subduction), causing volcanoes and earthquakes
What is a conservative plate boundary?
Where two plates slide past each other, causing earthquakes but no volcanoes.
What type of volcano is found at destructive plate margins?
Composite volcanoes – steep-sided and explosive.
What type of volcano is found at constructive margins or hotspots?
Shield volcanoes – wide and gently sloping with runny lava.
What causes earthquakes?
Sudden release of pressure due to tectonic plates grinding against each other.
What is the focus of an earthquake?
The point inside the Earth where the earthquake starts.
What is the epicentre?
The point on the Earth’s surface directly above the focus. Usually experiencing the most damage.
Give 3 primary effects of earthquakes.
Building collapse, injury/death, infrastructure damage.
Give 3 secondary effects of earthquakes.
Fires, disease, homelessness.
What is the difference between primary and secondary effects?
Primary = immediate impacts. Secondary = results of the primary effects.
Name two theories of plate movement.
Convection currents, slab pull, ridge push.
What is ridge push?
Gravity pulls newly formed, denser oceanic crust away from a mid-ocean ridge.
What is slab pull?
A sinking oceanic plate pulls the rest of the plate with it at a subduction zone.
What factors affect hazard risk?
Population density, level of development, capacity to cope, nature of the hazard.
Give an example of a tectonic hazard in an LIC.
2015 Nepal Earthquake.
What are the primary effects of a tropical storm?
Strong winds damage buildings, roads, and power lines
Heavy rain causes flooding and landslides
Storm surges lead to coastal flooding
Deaths and injuries from flying debris or collapsing structures
What are the secondary effects of a tropical storm?
Homelessness due to destroyed homes
Shortages of clean water, food, and medical supplies
Spread of disease (e.g. cholera)
Economic disruption: damage to businesses, transport, and agriculture
Long-term trauma or loss of income
What are immediate (short-term) responses to tropical storms?
Evacuation and rescue efforts
Emergency aid (food, water, shelter, medical help)
Temporary shelters set up
Restoring basic services (electricity, water, communication)
What are long-term responses to tropical storms?
Rebuilding homes and infrastructure
Improving flood defences and warning systems
Promoting education and awareness
Strengthening building regulations
Supporting economic recovery
