Natural Hazards Flashcards
(19 cards)
What are natural hazards?
Natural events that has the potential to cause damage, destruction and death.
Describe the distribution of earthquakes and volcanoes.
Earthquakes and volcanoes are located along tectonic plates
What happens on destructive plate margins ?
Two tectonic plates converging or coming together. Oceanic plate is sub-ducted beneath the continental plate. (Pressure causes magma to rise or creates an earthquake)
What happens on conservative plate margins?
Tectonic plates slide past each other (causing friction and pressure to build up).
What happens on constructive plate margins?
Tectonic plates more apart from one another. (Allowing magma to rise or causing a small earthquake)
What are earthquakes and their main features ?
A sudden or violent movement within the earth’s crust flowed by a series of shocks.
- the focus (where the earthquake starts)
-epicenter (the surface above the focus)
-seismic waves (the waves of energy)
How do we measure earthquakes? (name 2 ways)
- Seismometers
- Richter scale
Give an example of a tectonic hazard that occurred in a LIC.
-why did it happen?
Haiti earthquake (12 January 2010)
- Destructive plate margin (7.0 Richter scale)
Explain the primary and secondary effects of the Haiti 2010 earthquake
Primary-
220,000 killed
300,000 injured
100,000 houses destroyed
200,000 houses damaged
1.3 million homeless
Main port badly damaged
8 hospitals collapsed
Secondary-
2 million without food and water
Frequent power cuts
Increase in crime (looting and sexual violence)
Temporary shelters
Outbreaks of cholera
Explain the immediate and long term responses because of the Haiti 2010 earthquake
Immediate-
Aid slow to arrive (because of the damaged port)
10,000 rescue troops (sent by USA)
235,000 people moved into less damaged cities
UK government donated £20 million
Long-term -
Haiti dependent on overseas aid
New homes built to a higher standard (responds was slow)
1 million people still in temporary shelters a year after the earthquake
Port rebuilt (expensive)
Give an example of a tectonic hazard that occurred in a HIC.
-why did it happen ?
Christchurch earthquake (22 February 2011)
-conservative plate margin (6.3 Richter scale)
Explain the primary and secondary effects of the Christchurch 2011 earthquake
Primary-
181 killed
2,000 injured
50% of buildings damaged
City’s cathedral spire collapsed
Water and sewage pipes damaged
Secondary-
Businesses closed for a long time
Unable to hold 5 rugby World Cup matches
Schools closed for 2 weeks
Explain the immediate and long term responses because of the Christchurch 2011 earthquake
Immediate-
International aid was provided (estimated $6-7 million)
Aid workers from charities (e.g Red Cross) assisted
Areas zones to assess damage
300 Australian police officers flown in
Long-term-
$898 million in building insurance claims
Water and sewage were restored by August ( 6 months)
Temporary housing was provided
Why do earthquakes cause more loss of life in poorer countries than richer countries?
Poorly built infrastructure.
- buildings collapse more easily
What is the layer of air around the Earth called ?
Atmosphere
What 3 mechanisms cause plate movement ?
Slab pull
Ridge push
Convection currents
What is the pint under the Earth where an earthquake starts ?
Focus
What happens to tropical storms when they reach land?
They lose energy
Name the tectonic plate margin where two tectonic plates slide past each other
Conservative
