Paper 1 Section A Flashcards
What are natural hazards
Natural hazards are sudden, severe events which make the natural environment difficult to manage.
What 4 factors affect risk
Urbanisation,poverty,farming and climate change
What are the 2 types of crust and their characteristics
Oceanic-Dense and thin
Continental-Less dense and thicker
Describe the movements of plates at plate margins
Constructive-Plates separate forming new crust, causing volcanic eruptions
Destructive-Plates collide causing subduction, earthquakes, volcanic eruptions and fold mountains
Conservative-Plates slide by each other causing earthquakes
Hot spots is where….
some volcanoes occur due to the crust being thin allowing magma to break through the surface
Cause of the Chile earthquake
Subduction of one plate beneath another just off the coast of central Chile
Cause of Nepal earthquake
Plates colliding
Magnitude of Chile earthquake
8.8 shallow focus
Magnitude of Nepal earthquake
7.9 very shallow focus
Chile primary effects
.500 killed
.12,000 injured
.800,000 people affected
.$30bn damage
Nepal primary effects
.9,000 killed
.20,000 injured
.8m affected
.$5bn damage
Chile secondary effects
.Communities cut off by landslides
.Chemical plant fire near Santiago forced evacuations
Nepal secondary effects
.Communities cut off by landslides and avalanches
.Avalanches on Mount Everest killed 19 people
Chile immediate responses
.Key roads repaired within 24hrs
.Most power and water restored within 10 days
.$60m national appeal built 30,000 emergency wooden shelters
Nepal immediate responses
.Overseas aid included widely active NGOs-Oxfam
.300,000 people migrated from Kathmandu for shelter and support
Chile long-term responses
.Government reconstruction plan to help 200,000 households
.Full recovery within 4yrs likely
Nepal long-term responses
.International conference to seek technical and financial support
.Indian blockade in 2015 caused crippling fuel, medicine and construction material shortage
Why do people live at risk from tectonic hazards
.No experience or knowledge of the risks
.Volcanoes bring fertile soils, rich mineral deposits and geothermal energy
.Effective monitoring of hazards allow evacuation warnings to be given
How can risks from hazards be reduced
.Monitoring-Remote sensing(V) and microquakes(E)
.Prediction-Monitoring of volcanoes allows accurate prediction,accurate predictions for earthquakes are impossible due to a lack of clear warning signs but historical records can help determine possibility
.Protection-Earth embankments and explosives used to divert lava, drills for earthquakes helps keep people alert and prepared as well as strong infrastructure
.Planning-Risk assessment(V+E)
What do sinking and rising air create
.Sinking air-High pressure
.Rising air-Low pressure
Describe the movement of surface winds and what it creates
Surface winds move from high to low pressure, transferring heat and moisture from one area to another
What does the tilt and rotation of the earth cause
.Surface winds to curve and change seasonally
.Causes relative changes in the position of the overhead sun
Why is it cloudy and wet in the UK
Because 60 degrees north is close to where cold polar air from the north meets with the warm subtropical air from the south.Surface winds bring warm and wet weather as rising air cools and condenses forming clouds and rain.