Summary AQA GCSE Geography Section A: The Challenges of natural hazards Grade 9 notes
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Course
Geography
Institution
GCSE
These notes are for Paper 1 AQA Geography written into concise notes that can get you a Grade 9 when memorised. They include notes for all topics for Section A, Case Studies ( listed below) & topic specific exam questions .
Section A: The challenges of natural hazards, topics:
Natural Hazard...
AQA GCSE Geography Paper 1 notes:
Section A: Living with the physical
environment.
PAPER, I
SECTION A
Natural Hazards
● A natural hazard is a natural process which could cause death, injury, disruption to
people or destruction of property
● A natural disaster is a natural disaster that has actually happened
● Extreme events that do not pose any threat to human activity are not counted as
hazards
The two main types of hazards are:
● (1) Tectonic/Geological Hazards – volcanic eruptions, earthquakes
● (2) Weather hazards – these include tropical storms, heatwaves, floods, landslides
,TJ NOTES
● Hazard risk is the probability of people being affected by a hazard in a particular
area
The factors that affect hazard risk are:
(1) Vulnerability
● The more people exposed in an area at risk of natural hazards (population density),
the greater the probability that they will be affected by a natural hazard
● For example, an area with high population density on a flood plain is vulnerable to
flooding by extreme weather
● Vulnerability due to population density is often worsened by things like
urbanisation which leads to huge, densely-populated urban areas at great risk from
natural events as so many live in one place
● Also, poverty means more people are forced to live in these areas of high risk for
reasons like farming (because often flood plains have fertile deposits of silt), causing
people to move there for economic reasons
(2) Capacity to cope
● The better a population can cope with an extreme event, the lower the risk of them
being severely affected by the hazard
● Poverty often reduces capacity to cope as HICs tend to cope better as they have
better healthcare, response teams, search-and-rescue, more developed evacuation
protocols and defences than LICs so wealth is another major part of hazard risk
(3) Nature of Natural hazards
● This includes the type, frequency and magnitude of the hazard
● Type can influence how easy it can be predicted and protected against (e.g., tropical
storms can be predicted and monitored, earthquakes no, so slower response time)
● Higher frequency and magnitude means it is more likely people are going to be at
risk of injury or death because it is hitting more frequently and with a higher force
● The frequency and magnitude of extreme weather hazards are worsened by climate
change
,TJ NOTES
✔️Exam q check:
1.3 Explain how living in areas that are at risk from a tectonic hazard(s) may
have both advantages and disadvantages. (6marks)
Advantages of living in areas at risk from volcanic hazards:
• In volcanic areas geothermal energy can be harnessed by using steam from underground
heated by magma.
• Geothermal power stations produce electricity eg Iceland and New Zealand.
• Volcanoes, including hot springs and geysers, attract tourists. This creates employment
and may have a multiplier effect.
• Magma and lava may contain minerals including gold, silver, diamonds, copper and zinc.
Basalt can be used in construction and to build roads.
• Weathered lava may form nutrient rich soil which can be cultivated to produce crops and
rich harvests.
• New land may be created following a volcanic eruption.
• People believe the chances of the volcano erupting are very slim. Poor people, especially
in LICs cannot afford to live away from volcanoes as they provide jobs, and their families
and friends live there. Some places are well prepared for volcanic hazards so people feel
safe.
Disadvantages of living in areas at risk from volcanic hazards:
• Volcanic eruptions can kill people and damage property.
Economic activity can suffer as it is hard for businesses to operate after an eruption.
• Habitats and landscapes are damaged by lava flows.
• Ash disperses in the air, and together with volcanic gases can affect breathing. It may
cover the land, including fields, houses, roads, and industrial plants.
• Pyroclastic flows can destroy houses and trees. Eruptions may trigger tsunamis, which
lead to destructive flooding of the coastline.
Advantages of living in areas at risk from seismic hazards:
• Plate margins often coincide with favourable areas for settlement, such as coastal areas
where ports are developed. Large settlements in seismic zones offer job opportunities, such
as San Francisco and Los Angeles.
• Perception that risk is outweighed by economic or social opportunities.
• Engineering can make people feel safe eg Buildings can constructed to be earthquake
proof. Protection, planning and monitoring may be advanced, so potential risks are
reduced.
• Fault lines associated with earthquakes can allow water supplies to reach the surface.
Disadvantages of living in areas at risk from seismic hazards:
• In seismic areas ground shaking causes bridges and buildings to collapse, windows to
shatter, power lines to collapse, water/gas mains and sewers to fracture.
• Immediate deaths and injuries result from crushing, falling glass, fire and transport
accidents.
• People become homeless.
, TJ NOTES
• Slope failures set off avalanches.
• There may be panic, fear and hunger.
• Longer term disadvantages include diseases spread from polluted water, civil disorder,
looting, power cuts, reduced emergency services, unemployment, disability, loss of
farmland and food production.
Tectonic Plate Boundaries
● The Earth’s crust is divided into slabs called tectonic plates that float on the mantle
(a layer of semi-molten rock)
● Plates can either be continental (thick and less dense) or oceanic (thin and denser)
● Plates move around due to convection currents in the mantle
● The places where plates meet are plate margins/boundaries
● There are 3 different types of plate boundaries:
(1) Destructive
-Plates are moving towards each other due to
convection currents in the mantle
-The denser, oceanic plate subducts underneath
the less dense continental plate into the mantle,
creating gas-rich magma pools as the crust melts.
-These magma pools then rise to the surface
through cracks in the crust called vents, erupting
and forming a volcano as the lava cools
-As subduction takes place, the oceanic plate gets
stuck as it moves through, causing tension to
build and the pressure releasing in the form of
violent seismic waves
-Ocean trenches also form
-When two continental plates meet at a
destructive boundary, ground folds upwards to
form fold mountains
(2) Constructive
This is where two plates are moving away from
each other due to convection currents in the
mantle
Magma will rise to fill the gap created, and will
cool to form a volcano
As the plates move away, tension builds along
the cracks where they are moving away and, as
magma forces its way through them, minor
earthquakes take place
(3) Conservative
-Plates are moving past each other or in the
same direction at different speeds due to
convection currents in the mantle
-As the plates grind past each other, they get
stuck, tension builds and energy is released in
the form of seismic waves
-No magma is involved in this, so no new crust is
created or destroyed and no volcanic eruptions
happen at conservative plate boundaries
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