Hazards Flashcards
LICs
Low Income Countries have a GNI per capita below $1045
HICs
High Income Countries have a GNI per capita greater than $12,746
NEEs
Newly Emerging Economies are countries that have begun to experience higher rates of economic development, usually due to higher levels of industrialisation
Hazard Risk
The probability or chance that a natural hazard may take place
Natural Hazard
A natural event that threatens people or has the potential to cause damage, destruction and death
Conservative Plate Margin
Tectonic plate margin where two tectonic plates slide past each other
Constructive Plate Margin
Tectonic plate margin where plates moving apart (diverging) allow magma to rise and form new land
Destructive Plate Margin
Tectonic plate margin where plates are moving towards each other (converging) and the oceanic plate subducts
Can cause violent earthquakes and explosive volcanic eruptions
Plate Margin
Boundary between two tectonic plates
Planning
Actions taken to enable people and communities to respond to, and recover from, natural disasters e.g. emergency evacuation plans, warning systems, etc.
Prediction
Attempts to forecast when and where a natural hazard will strike, based on current knowledge
Earthquake
A sudden or violent movement within the Earth’s crust, followed by a series of shocks
Immediate Responses
The reaction of people as the disaster happens and in the immediate aftermath
Long-term Responses
Later reactions that take place in the months and years following the disaster
Monitoring
Recording physical changes, such as earthquake tremors around a volcano, to help forecast when and where a natural hazard may strike
Primary Effects
The initial impact of a natural event on people and property, caused directly by it
Protection
Actions taken before a hazard strikes to reduce its impact
Secondary Effects
The after-effects that occur as an indirect result of a natural event, sometimes on a longer timescale
Tectonic Hazard
A natural hazard caused by the movement of tectonic plates (including volcanoes and earthquakes)
Tectonic Plate
A rigid segment of the Earth’s crust which floats across the heavier, semi-molten magma below
Volcano
An opening in the Earth’s crust from which lava, gases and ash erupt
Economic Impact
The effect of an event on the wealth of an area or community
Environmental Impact
The effect of an event on the landscape and ecology of the surrounding area
Extreme Weather
When a weather event is significantly different from the average or usual weather pattern, and is especially severe or unseasonal
Global Atmospheric Circulation
The worldwide system of winds which transports heat from tropical to polar latitudes
Management Strategies
Techniques of controlling, responding to, or dealing with an event
Social Impact
The effect of an event on the lives of people or community
Tropical Storm
An area of low pressure with powerful winds moving in a spiral around the calm central point (the eye) and heavy rainfall
Adaptation
Actions taken to adjust to natural events, such as climate change, to reduce potential damage, limit the impacts, take advantage of opportunities, or cope with the consequences
Climate Change
A long-term change in the earth’s climate, especially due to an increase in the average atmospheric temperature
Mitigation
Actions taken to reduce or eliminate the long-term risks to human life and property from natural hazards
Orbital Changes
Changes in the pathway of the Earth around the Sun
Quaternary Period
The period of geological time from about 2.6million years to the present, characterised by the appearance and development of humans and includes the Pleistocene and Holocene Epochs
Examples of Tectonic Hazards
Volcanoes
Earthquakes
Tsunamis
Avalanches
Examples of Climatic Hazards
Flooding
Tornadoes
Tropical Storms
Droughts
Mantle
Thickest part of the Earth (around 2900km) made up of semi-molten rock, known as magma
Outer Core
Liquid layer of iron and nickel surrounding the inner core
Inner Core
Centre of the Earth, with temperatures up to 5500 C, made up of iron and nickel
Oceanic Crust
Found underneath oceans, and is dense enough to be subducted at converging plate margins
Continental Crust
Found under land mass or continents, less dense than oceanic crust so rarely subducts
Ring of Fire
An area located along the plate margin of the Pacific plate, with a lot of volcanic activity
Richter Scale
A measure of how powerful an earthquake is (magnitude)
Examples of Earthquake protection in buildings
- rubber shock absorbers in foundations
- steel frames that sway during Earth movements
- open areas outside for evacuation
Magma Chamber
Where molten rock is stored beneath the ground
Main Vent
Channel through which magma reaches the surface
Secondary Vent
Some magma may escape through the side of the volcano, particularly if the main vent gets blocked
Crater
The top of the volcano, where the lava erupts from
Positive effects of volcanoes
- geothermal power generation
- ash acts as a good soil fertilizer
- attract tourists
Negative effects of volcanoes
- risk to life during eruptions
- economic activity can suffer, as it is hard to operate a business
- habitats and landscapes damaged by lava flow
Characteristics of composite volcanoes
- acidic, viscous lava
- steep sides, as lava solidifies quickly
- alternate layers of ash and lava (stratovolcanoes)
- violent eruptions
- longer periods between eruptions
Shield volcanoes
- basic, runny lava
- gentle sides, as lava flows far before it solidifies
- no layers; only consists of lava
- less violent eruptions
- more frequent eruptions
Seismometer
Used to measure earthquakes near an eruption
Tiltmeters / GPS
Monitor changes in landscape to predict eruptions
Ways of monitoring volcanoes
- seismometers
- tiltmeters / GPS
- measuring gases released from volcano
- measuring temperature
- past history of eruptions
Benefits of living by a volcano
- fertile land from volcanic rock and ash increases crop yields
- tourists increase money to the local economy
- geothermal energy provides cheaper electricity for locals
- minerals in lava e.g. diamonds, can be mined to make money
Hurricanes
Tropical storms in the US and the Caribbean, characterized by powerful winds and heavy rainfall
Cyclones
Tropical storms in South Asia, characterized by powerful winds and heavy rainfall
Typhoons
Tropical storms in East Asia, characterized by powerful winds and heavy rainfall
Explain how tropical storms develop
- form between 5 and 30 degrees latitude and move westward because of easterly winds
- warm ocean (at least 27 C) heats the air above it, causing an area of low pressure
- rising air draws up more warm moist air leading to strong winds
- rising warm air spirals upwards, cools, condenses and forms large clouds
- these clouds form the eye wall, producing heavy rainfall
- cold air sinks in the centre of the storm, creating calm, dry conditions
The effect of climate change on tropical storms
- warmer ocean temperatures are more likely to cause hurricanes
- wind speeds potentially increasing 2-11%
- rainfall rates in these storms projected to increase by around 20%
Depressions
Areas of low atmospheric pressure, which bring changeable weather as they travel
Anticyclones
Areas of high pressure formed when cool air sinks, that spin in an anticlockwise direction
Brings hot, sunny weather in summer and cold weather (e.g. fog, frost) in winter
Relief Rainfall
- warm, moist air rises over mountains
- cools and condenses, forming clouds and rain
- having passed over the mountain, it descends and cools
- this creates drier conditions, known as a rain shadow
Convectional Rainfall
- sun heats the land, creating convection currents
- warm air rises, cools and form clouds
- clouds produce heavy rainfall or thunderstorms
Frontal Rainfall
- warm front meets a cold front, so cold air sinks, forcing the warm air to rise
- warm air rises, cools and condenses to form clouds
- clouds can bring heavy rain
Greenhouse Effect
- short-wave radiation from the sun passes through atmosphere and heats the Earth’s surface
- Earth’s surface gives off heat as long-wave radiation
- some of this heat is trapped and reflected back to Earth by greenhouse gases
- this process heats up the Earth
Examples of greenhouse gases
Carbon Dioxide Methane Sulphur Dioxide Water Vapor Nitrous Oxides
Human factors increasing global warming
- fossil fuel use
- deforestation
- landfill
- agriculture
Physical factors affecting global warming
- orbital changes
- volcanic activity
- solar output
Impacts of climate change in the UK
- rising sea levels cover low-lying areas, particularly in the East
- droughts, floods and other extreme weather becomes more likely
- pressure on water supplies during hotter summers
- industry may be impacted, damaging local economy e.g. Scottish ski resorts
Impacts of climate change around the world
- sea levels rising will affect 80 million people
- tropical storms will increase in magnitude
- species in affected areas (e.g. the Arctic) may become extinct
- diseases, such as malaria, become extinct, affecting up to another 280 million people
Climate change mitigation strategies
- alternative energy
- carbon capture
- planting trees
- international agreements
Climate change adaptation strategies
- agriculture
- water supply
- reducing risk from sea level rise
How does alternative energy mitigate the effects of climate change
Fossil fuels release carbon dioxide, which is a greenhouse gas, so generating power in other ways slows down global warming
Carbon Capture
The removal of carbon dioxide and its storage underground, reducing emissions into the atmosphere
Afforestation
The planting of more trees to absorb more CO2 (which trees use for photosynthesis) and mitigate the effects of global warming
Agriculture (climate change adaptation)
Some farmers may not be able to grow their crops in warmer climates, so they must plant other crops
Water Supply (climate change adaptation)
Water transfer schemes transport water to areas with water shortage to cope with rising temperatures and droughts
Marginal Land
Land that is difficult to develop and yields little profit
Convection Currents
Movements within the Earth’s mantle caused by the heat of the core
Subduction
When one tectonic plate is forced under another
Moment Magnitude Scale (MMS)
Used to measure the magnitude of Earthquakes, in terms of the amount of energy released
Hotspot
Occurs when there is intense heat in the mantle which rises towards the crust. When the magma reaches the surface, it creates volcanoes e.g. the Hawaiian islands
Lahar
A destructive volcanic landslide or mudflow, consisting of a mixture of volcanic debris, mud, rock and water
Pyroclastic Flow
A current of hot gas and rock that flows downhill at high speed
Volcanic Bombs
Large blocks of hot rock thrown from a volcano
Coriolis Force
Apparent force, due to the spinning of the Earth, which deflects movement of particles and wind
Cumulonimbus
A type of large, dense, tall, grey cloud which produces rain, hail or snow
Displacement
When people are forced to leave their homes or countries, usually due to war or natural disaster
Rain Shadow
An area with reduced rainfall because it is behind higher land
Ice Core
A sample of ice, taken by drilling through a glacier or ice sheet
Milankovitch Cycles
A theory that describes the effects of the Earth’s movements on its climate
