tectonic hazards Flashcards
ways to manage hazards
- prediction
- protection
- preparation
what is prediction
using past evidence to determine when earthquakes may happen and where
what is preparation
identifying the buildings most at risk - eg hospitals and schools - and protecting them
what is protection
designing buildings that will withstand hazards
building controls examples
shutter windows, deep foundations, shock absorbers
what is a natural hazard
a natural hazard is an natural event, like volcanoes and earthquakes, that poses a threat to society
types of natural hazards
geological hazards - volcanoes, earthquakes
meteorological hazards - tropical storms
different factors that affect hazard risk
- urbanisation
- poverty
- capacity to cope
- nature of the hazard (type, magnitude, frequency)
layers of the earth
- crust
- mantle
- outer core
- inner core
types of plate margins
destructive plate margins
constructive plate margins
conservative plate margins
what is a destructive plate margin
in a destructive plate margin, the plates are moving towards each other. this is a zone of subduction
what is a constructive plate margin
in a constructive plate margin, the plates move away from each other, and the magma rises from the mantle to fill the gap, cools, forming new crust
what is a conservative plate margin
in a conservative plate margin the plates are either moving in different speeds in the same direction or moving past each other
where are volcanoes formed
destructive or constructive
how is a volcano formed
in a destructive plate margin, the denser oceanic plate sinks under the less dense continental plate as they move towards each other. as the oceanic plate sinks it is heated by the mantle, and melts. this is less dense than the magma so it rises, breaking through the continental crust, forming a volcano
where are earthquakes formed
at all plate margins
tension build up in each plate margin
constructive - plates move away from each other and
general primary effects of earthquake
- buildings and bridges destroyed, homes collapsed
-people killed or injured by collapsed buildings and debris falling - roads, railways and airports damaged
- water pipes, gas pipes, electricity cables damaged
general secondary effects of earthquake
- can trigger landslides or tsunamis
- leaking gases can be ignited, starting fires
- shortage of clean water, diseases can spread easily
- repairs and reconstruction can be very expensive
general immediate responses to an earthquake
- recovering of dead bodies to prevent spread of disease
- put out fires
- temporary shelters set up for those with homes damaged
- rescue people trapped by buildings
general long term responses to an earthquake
- re-house people who have lost their homes
- reconnect electricity, gas and water pipes
- improve building regulations to keep buildings protected from future earthquakes
- set up initiatives to help economic recovery. eg. tourism promotion
general primary effects of a volcano
- buildings and roads destroyed by lava flows and pyroclastic flows
- people and animals injured or killed
- crops damaged, water polluted by ash
- suffocation by volcanic gases
general secondary effects of a volcano
- transport networks blocked
