Geography Unit 1 World At Risk

My exam is on Thursday and I made this little revision guide for Unit 1, I basically went through the specification and got down everything I needed to know. Hope this helps!

HideShow resource information
  • Created by: emrana
  • Created on: 21-05-12 19:30
Preview of Geography Unit 1 World At Risk

First 491 words of the document:

Geography Revision: World at Risk
There are two types of hazards, geophysical (to do with tectonic/geological processes) and
hydro-metrological (to do with water and atmosphere).
Geophysical hazard Hydro-metrological hazard
Volcano Cyclone
Opening within Earth's crust, where magma, Area of low atmospheric pressure created when
gases, ash and dust are ejected. air rises from surface of Earth. It is then cooled
~ Volcano lava helps create Volcano lava helps and condensation occurs. After that clouds form
create new land, e.g. Iceland was created this and then precipitation. The air that is rising is
was and now 300,000 people live near it unstable which brings wind.
~ They can be dormant (sleeping) or extinct ~They are formed by warm ocean water
Earthquakes ~Cyclones can also be called: hurricanes,
Series of vibrations on earth. They are caused by typhoons, wet willies.
movements of rock within the Earths lithosphere ~They grow in size and strength when over
Landslides and Avalanches warm water but when they go to land it loses
Landslides ~ large amounts of rock or soil strength.
moving down a slope (usually by gravity) Droughts
Avalanches ~ large amounts of snow or ice Extended long period of lower than average
moving down mountainous regions precipitation: causes water shortage
**Both triggered by specific event e.g. rainfall or Floods
earthquakes Land that is dry becomes inundated.
~Often occurs after long period of rainfall
which causes water to burst banks and overflow.
~Mainly happen to low lying countries
Types of plate boundaries
Conservative; 2 plates pulled in different directions, or different
speeds because of convection currents in the mantle. Plates lock
together as the crust isn't smooth and then pressure builds up along
the fault line because the plates are being pulled and then then
plates move suddenly and slide past each other causing an
earthquake due to friction.
Divergent; 2 plates pulled apart from each other because of
convection currents in mantle. As plates move apart there's a gap
which is filled by magma rising from the mantle and that creates
new crust. Volcanoes are very common and so are earthquakes
(due to friction from plates being pulled).
Continent to Continent; happens at convergent plate boundary. The two continent plates
are pulled towards each other and the plates buckle and fole to make a mountain as neither
plate is heavy enough to sink.
Ocean to Ocean; happens at convergent plate boundary. Two ocean plates colliding, the
heavier oceanic plate goes under the other plate because it's heavier. A deep ocean trench
is formed because the ocean plate starts to subduct. Oceanic plate melts into magma
because of friction and pressure, magma then ruses up and volcanoes and earthquakes
Emrana Khatun 1

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

After several eruptions, the volcano will grow above sea level to from an island and
make an island arc.
Ocean to Continent; ocean and continent plate go towards each other because of
convection currents in the mantle. The ocean plate is forced to go under because it is heavier.
Deep ocean trench is formed because the ocean plate starts to subduct.
~Fold mountains form beacause the pressure builds up on land.…read more

Page 3

Preview of page 3

Here's a taster:

Global Hazard Patterns
Deaths Cost
Better technology to predict these hazards, even the small ones
More prepared, better technology, equipment and buildings
More developed insurance companies.…read more

Page 4

Preview of page 4

Here's a taster:

El Nino
Warm ocean current that appears off the west coast of South America.
It replaces the cool ocean current which is usually found.
It is used to describe a pro longed period of warmer-than-average conditions that occurs
because of the warm ocean current
It usually happens for 12-18 months
El Nino events happen every 2-7 years
Increases number of hazards:
~Droughts in S.E. Asia, S. Africa, E. Australia
~Floods in east of pacific e.g.…read more

Page 5

Preview of page 5

Here's a taster:

West coast of USA
North American plate and the Pacific Plate
The San Andreas Fault (fracture within crust of Earth, forms the boundary between the two
plates). Fault travels nearly the entire length of coast,
Cities located on this fault. E.g. LA, Santa Barbra, San Diego
50mm of movement each year
Experiences between 100 and 150 earthquakes annually
Experiences impacts from ENSO:
~drought which leads to a strain in water supplies as there is a rising population
~River flooding, e.g. LA.…read more

Page 6

Preview of page 6

Here's a taster:

Long Term:
CO2 levels; bubbles trapped in ice from Greenland and Antarctica ice cores. Cores removed
from ice sheet reveal layers going down. Each layer records reason of snowfall.
Oxygen isotope record; sampled from ice cores and ocean sediments. Ratio of oxygen 16 to
oxygen 18 isotopes is a good indicator of past sea levels
Pollen; extracted from sediment cores in lake beds. Pollen sequences show how ecosystem
has changed
Medium Term:
Historic records; analysis photos, painting, etc.…read more

Page 7

Preview of page 7

Here's a taster:

TIPPING POINT: When damage from climate change occurs irreversibly at an increasing rate
Vegetation shifts; going northwards, which will destabilise the food webs but will benefit
Thawing permafrost; 40% expected to thaw e.g. Siberia. This will release large amounts of
methane. Also lakes and rivers will draw as frozen ground under them thaws. Whereas in
other areas rising rivers create new wetlands which will impact species e.g.…read more

Page 8

Preview of page 8

Here's a taster:

Examples: setting targets to reduce CO2 emissions, `capturing' carbon emissions from power
stations and storing them for instance in spent oil wells, switching to renewable resources e.g. wind
1997, Japan, reduce emissions by 5% by 2012.
Only USA didn't sign
Not been a huge success, lots of countries off track e.g. Germany, Spain and Japan.…read more

Page 9

Preview of page 9

Here's a taster:

Carbon Offsetting
Carbon offsetting is a credit system, called carbon credits, which aims to reduce greenhouse
gas emissions
Carbon credits allow companies to pollute, but at a cost
Each credit costs money which polluters have to pay, and is in proportion to the pollution
The cost encourages companies to look for other ways of production by polluting less or not
at all
National Strategies
UK; aims to reduce CO2 emissions by 60% by 2050.…read more

Page 10

Preview of page 10

Here's a taster:

Lack of water leads to dehydrations, also diseases spread quickly
Lack of work, can't afford to look after family
Bad housing, prone to collapse dies to hazards
Population growth, poverty increases
Little healthcare, diseases spread
Debt, can't afford to pay off, stuck in debt
Sustainable development: strategies
Developing eco-friendly and green strategies; Working with nature, conservation of
biodiversity clean development of mechanisms ( e.g.…read more


No comments have yet been made

Similar Geography resources:

See all Geography resources »See all resources »