Living With The Physical Environment - Natural Hazards Flashcards
Natural Hazards
A natural event that poses as a threat to humans and/or property
Atmospheric hazards
Tornadoes
Droughts
Geological hazards
Earthquakes
Volcanoes
Flooding hazards
Avalanches
Tsunami’s
Hazard risk
Chance of being affected by a natural hazard
Factors affecting risk
Urbanisation
Poverty
Farming
Climate change
Earthquakes
A sudden or violent movement within the earth crust
Volcano
An opening in a planets crust through which molten rock, hot gases, and other materials erupt
Convection currents
Heat-driven cycles that occur in the mantle
Constructive plate margins/boundaries
Two plate boundaries move apart
As a gap appears magma forces its way upwards breaking through the overlying crust
This causes earthquakes
E.g. Azares
Destructive plate margins/boundaries
Two plates are moving towards each other
The oceanic plate is subducted beneath the continental plate
Friction is built up and released through an earthquake
The continental plate melts, forming magma that breaks through the surface to form a steep-sided volcano
E.g. Andes
Collision plate margins/boundaries
Two plates are moving towards each other
The two plates collide and the crust uplifts forming folded mountains
This process causes earthquakes
E.g. San Andreas Fault
Conservative plate margins/boundaries
Two plates move past each other
Friction causes earthquakes
E.g. The Himalayas
Nepal case study - Facts
Date - 25/4/2015
Magnitude - 7.9
Plate boundary - destructive
Nepal case study - Primary effects
Social - 9000 died, 20000 injured, 8 million (1/3 of the population) affected
Economic - cost $5 billion, 50% of shops destroyed
Environmental - no power or water supplies