natural hazards Flashcards
definition of a natural hazard
are extreme natural events that cause loss of life, extreme damage to property and disrupt human activities
types of natural hazard
meteorological-weather, atmosphere or climate eg. hurricanes and bush fires
geological-are caused by the Earth and the movement of tectonic plates eg. volcanoes and earthquakes
factors affecting hazard risk
population-As the world population increases, more people live in areas which are vulnerable to natural hazards
Urbanisation and population density
frequency and magnitude
level of development
prediction
human activities
global distribution of earthquakes and volcanoes
around the Pacific ring of fire
occur at all types of plate boundaries
along the mid-atlantic ridge-underwater mountain range in the Atlantic Ocean
in the Himalayan region-eurasian plate and Indian plate
global distribution of tropical storms
they primarily form at the tropics specifically between 5 degrees and 30 degrees north and south of the equator where sea temperatures
seasonality of tropical storms
they occur in late summer when sea temperatures are highest over 26/27 degrees and tropical storms require high sea temperatures to form
what is the link between surface winds and air pressure?
Sinking air causes high pressure which leads to winds moving away
Hadley Cell:rainforests
it is between the equator and 30 degrees northern latitude
air rises which causes an area of low pressure
cools and condenses to form clouds
climate=hot-heat form the sun and wet due to the rain
rainforests are very common here
Hadley Cell:deserts
heated air has risen at the equator it divides
half=north half=south
30 degrees northern latitude-it becomes cool and starts to sink
sinking air creates high pressure
clouds cannot form-worlds deserts
characteristics of tropical storms
sea temperature to be at least 26 degrees for several days
sea depth
location between 5 and 20 degrees of the equator
formation of tropical storms
begin at sea
very moist and warm rises rapidly
(the warmer the air the more moisture it holds)
forms thunderclouds
why is there a lot of rainfall at the equator?
the air rises rapidly as it is heated by the sun along the equator. then it cools and condenses to form clouds
primary effects of the Haiti earthquake
-an estimated three million people were affected by the quake
-217,000-230,000 people died
-300,000 people were injured
- 1 million made homeless
-30,000 commercial building collapsed
secondary effects of the Haiti earthquake:
-two million people were left with food and water
-regular power cuts occurred
-crime increased-sexual violence and looting escalated
-by November 2010, there were outbreaks of cholera
Immediate responses:
due to the port being damaged aid was slow to arrive
-The USA sent rescue teams and 10,000 troops
-235,000 people moved away from Port-au-Prince
-£20 million pounds were donated by the UK government
