- Created by: Tom
- Created on: 05-12-11 21:04
Unit 1 World at risk - Global hazards
Natural hazard - a natural process that poses a potential threat to human life or property
Hydrometeorological hazard - caused by climatic processes
Geophysical hazard - caused by land processes
Natural disaster - when a hazard seriously affects humans
Risk - The likelihood that humans will be seriously affected by a hazard
Vulnerability - How susceptible a population is to the damage caused by the hazard
Capacity to cope - the ability to deal with the consequences of a hazard
Constructive plate boundary - 2 plates moving apart
Destructive plate boundary - 2 plates moving together
Conservative plate boundary - 2 plates moving side by side
Continental crust - is thicker but less dense and mostly above sea level
Oceanic crust - is thinner but more dense and mostly below sea level
Subduction zone - when the pressure builds between 2 plates in a conservative plate boundary, causing the pressure to be eventually released as the oceanic plate subducts
Tropical cyclones/hurricanes/typhoons - are big storms with strong winds and torrential rain
Disaster Hotspot Case Study - California
Disaster hotspot - a vulnerable place at risk from 2 or more hazards
San Andreas Fault - Conservative plate boundary
Past disasters include the San Francisco earthquake of 1906 thought to have measured 7.8.
Some hazards can increase the likelihood of other hazards occuring
Droughts - caused by anticyclones (long lasting periods of high air pressure with dry sinking air leads to no rain). Can be caused by La Nina - leads to less evaporation and precipitation. Can also be caused by increased wind blowing westward from desert areas in east California. Causes wildfires.
Tsunamis - can be causedd by earthquakes on the sea bed or landslides into the sea. Earthquake of the coast of Alaska in 1964 caused a tsunami to strike north Californian coast - killed 12 people in Crescent City
Landslides - Land can be made unstable by coastal erosion or extreme weather or earthquakes. Risk of landslides high because there's a lot of building on steep slopes.
Volcanoes - Hasn't been a volcano eruption since 1915 (Lassen Peak).
Population is vulnerable - More than 70% of population within 50km of a fault line. Lots of building on unstable land- can lead to soil liquefaction during earthquake increases risk of landslide - Loma Prieta earthquake of 1989. Building along coast.20% of residents in LA live below poverty line - have lowest capacity to cope.