Natural Hazards Flashcards
Define natural hazard
A natural hazard is a natural event that has the potential to cause damage, destruction and death when it interacts with humans.
What are the types of natural hazards?
Earthquakes, volcanic eruptions, tropical storms, floods
What are some factors affecting hazard risk?
Population
Level of development and wealth
Magnitude
Frequency
Location
The 3 Ps
What happens at a conservative plate margin?
The two tectonic plates slide past each other.
What happens at a constructive plate margin?
Rising magma adds new material to plates that are moving apart from each other.
What happens at a destructive plate margin?
The two plates are coming together and the oceanic plate is subducted.
What is monitoring?
Recording physical changes such as earthquake tremors around a volcano to help forecast when and where a natural hazard might strike.
What is planning?
Actions taken to enable communities to respond to, and recover from natural disasters like emergency evacuation plans, information management communications and warning systems.
What is prediction?
Attempts to forecast when and where a natural hazard will strike, based on current knowledge. This can be done to some extent for volcanic eruptions, but less for earthquakes.
What is protection?
Actions taken before a hazard strikes to reduce its impact, such as educating people or improving building design.
Oceanic crust characteristics:
Most less than 200 million years old
less than 10km thick
very dense - sinks
Continental crust characteristics:
Most over 150 million years old
Between 25-70km thick
not very dense - cannot sink
What happens at a collision plate margin?
The plates collide, pushing up the land, forming mountains
Where can volcanoes occur?
constructive and destructive plate boundary, and hotpots
What are hazards of volcanoes?
Volcanic gases
Landslides
Lahars
Lava flows
Pyroclastic flows
Tephra (volcanic bombs)
