1) Hazardous Earth Flashcards
What are winds?
Movements of air on a large scale
What causes winds?
Differences in air pressure
What causes differences in air pressure?
Different temperatures causing movement
How does air pressure affect winds?
WInds mmove from high pressure areas to lower pressure areas
What are the 3 atmospheric circulation cells called?
Hadley
Ferrel
Polar
What does cool sinking air form?
High pressure belts of wind
What does warm rising air form?
Low pressure belts on wind
How many global atmospheric circulation cells do the North and Suth poles have each?
3
What are westerlies?
Surface winds that blow from 30 degrees to the poles
What direction do westerlies blow in the southern hemisphere?
North-west to south-east
What direction do westerlies blow in the northern hemisphere?
South-west to north-west
What are trade winds?
Surface winds that blow from 30 degrees to the equator
What direction do trade winds blow in the southern hemisphere?
South-east to north-west
What direction do trade winds blow in the northern hemisphere?
North-east to south-west
What does the global atmospheric circulation model describe?
How air circulates between low and high pressure belts
What happens to air at 30 degrees?
Cool air falls
High-pressur ebelt with minimal rainfall and no clouds
What happens to air at 60 degrees?
Cold air blown from poles meets warm surface winds
RIses and forms a low pressure belt
Air splits, some to equator and some to poles
What happens to air at the poles?
Cool air sinks
High pressure belt
Moves back towards equator as surface winds
What do ocean currents transfer?
Heat from warmer to cooler areas
What do surface currents do?
Transfer heat from the equator to cooler regions
What are deep ocean currents caused by?
Differences in water density
What is thermohaline circulation?
1) Water freezing at the poles causes the surrounding water to become saltier and denser
2) Sinking of dense water lets warm water flow near the surface which cools and sinks creating a cycle
What are surface currents caused by?
Winds
What determines arid and dry regions?
Pressure belts
What causes tropical climate zones?
Air rising where Hadley cells meet creating low pressure belt
What causes arid climate zones?
Air sinking where Ferrel and Hadley cells meet creating high pressure belt
What is the name of the circulation system that causes deep ocean currents?
Thermohaline circulation
At what latitude does cool air sink?
30 degrees
What climate period are we currently in?
Quaternary period
Which period came before the quaternary period?
Neogene
How long do glacial periods last for?
Roughly 100,000 years
How much do scientists predict the earth’s temperature to have risen by by 2100?
4 degrees since 1880
When does the greenhouse effect happen?
When greenhouse gases absorb heat that has been reflected off the Earth and re-radiate this heat back towards Earth
What 4 methods are evidence for climate change?
Tree rings
Ice cores
Temperature records
Pollen analysis
How does pollen analysis provide evidence for climate change?
Plant pollen can be preserved in sediment
Comapring pollen from sediment to current plant pollen can indicate differences
How do temperature records show climate change?
Temperatures have been recorded since 1850
Very reliable but not very old
How do ice cores show climate change?
Each year a new layer of ice freezes on top of an ice sheet
Examining gases in each layer shows what temperatrue was like hundreds of years ago
How do tree rings show climate change?
Every year a new ring forms
Rings are thicker in good conditions for growth (wet, warm)
Gives data for up to the last 10,000 years
What are natural causes of climate change?
Oribtal changes
Asteroid collisions
Volcanic activity
Solar output variation
What is the Milankovitch cycle?
Earth’s orbit changes from circular to elliptical and back every 96,000 years
How do oribtal changes cause climate change?
When the Earth is closer to the sun, more of the sun’s radiation will warm the Earth
How do asteroid collisions cause climate change?
Collisions with Earth cause last amounts of dust particles to reduce the amount of sunlight reaaching Earth
How does volcanic activity cause climate change?
Eruptions can release carbon dioxide
Particles can reflect the sun’s radiation
What is a volcanic winter?
When particles from volacnic eruptions prevent sunlight from warming the earth
What human factors cause climate change? (4)
Industry
Energy
Transport
Farming
How does farming cause climate change?
Livestock produce methane during digestion
How does transport cause climate change?
Most modern cars run on fossil fuels
How does energy cause climate change?
Fossil fuels are burnt releasing carbon dioxide
How does industry cause climate change?
Cement production produces greenhouse gases
Decay of industrial waste produces methane
What evidence is there that human activity is causing climate change? (4)
Declining arctic ice
Global temperature rise
Sea level rise and warming oceans
Increased extreme weather events
What are effects of climate change on the environment? (5)
Changing precipitation patterns Changing distribution of species Sea surface temperature increase Reduction of biodiversity Melting ice
What are rising sea surface temperatures casuing to happen?
Bleaching of corals
More severe cyclones
What negative effects does a changing distribution of species have on the UK?
Malaria and exotic diseases will become present
What are effects of climate change on people? (5)
More deaths due to heat Lower crop yields Problems with water availability Loss of coastal areas More extreme weather events
How uses projection graphs to predict temperature and sea level changes?
The Intergovernmental Panel on Climate Change (IPCC)
What are the 4 predicted temperature scenarios?
1) Greenhose gas levels peak and fall (government must reduce carbon emissions)
2 + 3) greenhouse gas levels continue to rise until they flatten out
4) Emissions continue to increase without any action taken
Why is there uncertainty about the future of climate change?
We don’t know what technologies could produce more efficient energy
We don’t know what governments will do
Catastrophe could kill billions
What type of system is predicting climate change?
A complex system
What are the conditions needed for tropical storms to form?
Water over 26.5 degrees
Difference in wind speeds between the upper and lower atmosphere
What is dissipation?
The strength of a storm faling as it moves away from warm water
Where is the source area for most cyclones?
Between 5 and 30 degrees of the equator
What effect causes cyclones to spin?
The Coriolis Effect
What direction do tropical storms move in?
East to west
What causes the Coriolis effect?
The rotation of the Earth
What are features of tropical storms? (3)
Hundreds of km wide
Last 7-14 days
Circular shape
What are features of the eye of the storm?
Central
Cool air descending from eyewall creats eye up to 50km wide
No rain and low pressure
What are features of the eyewall?
Surrounds sides of the eye
Hot air rises
Strong winds
Lots of rain
What are conditions at the egde of cyclones?
Intermediate
Moderate wind, rain, temperature
Clouds small and scattered
What are physical hazards of tropical cyclones? (5)
Intense rainfall High winds Coastal flooding Landslides Storm surges
What are storm surges?
Large sea level rises brought about by high winds and low pressure
What can intense rainfall lead to?
Mudslides / landslides
What are impacts of tropical cyclones on the environment?
Uprooted and killed trees
River and lake widlife harmed by sewage
Coastal habitats amaged
Land salinated
What are impacts of tropical cyclones on people?
Death and injury
Damaged transport infrastructure
Food shortages
What 3 main features determine the vulnerability of a country to tropical storms?
Geographic
Economic
Social
How does social vulnerability effect impacts of cyclones?
Lower-income nations have lower quality housing and worse emergency services
How does economic vulnerability effect impacts of cyclones?
Less money to spend on flood defenses or aid
Higher % of population in agriculture
What kind of areas are vulnerable to cyclones?
Low-lying coasts
Regions on the tropical cuclone path
How can impacts of tropical cyclones be reduced? (3)
Weather forecasting
Protection
Evacuation
Who builds models to try and forecast the weather?
Meteorologists
When did Hurricane Katrina strike?
29th August 2005
Where did Katrina strike?
Mississippi and Lousiana
New Orleans
What category was Katrina?
3
Why did New Orleans suffer badly from Katrina?
Its flood defenses (levees) broke
How did USA prepare for Katrina?
Weather forecasting
Poorly engineered levees
What were impacts of Katrina on the environment?
Sewage entered water supply
Oil spills from damaged oil refineries
Conservation areas flooded
What are the 3 layers of Earth?
Core
Mantle
Crust
What are features of Earth’s core?
Solid inner core
Liquid outer core
Iron and nickel
5,000 degrees
What are features of Earth’s mantle?
Semi-molten rock 3 layers: Rigid core layer Semi-molten middle asthenosphere Solid top layer like crust 3,000 degrees
What are features of Earth’s crust?
5-100km thick
Floating on semi-solid mantle
Broken into pieces called tectonic plates
Continetnal crust / oceanic crust
What are features of the oceanic and continental crust?
Oceanic- thinner, denser
Continental- thicker, less dense
How do tectonic plates move?
1) Earth’s core produces heat through radioactive decay
2) Heat transmitted to lower layer of asthenosphere which gets hotter and rises towards surface as it becomes less dense
3) Magma in asthenosphere gets cooler as it is further away from core so becomes denser and sinks
Called convection currents
What are plate margins?
Places where 2 tectonic plates meet or sit next to each other
What are the 3 main types of plate margin?
Destructive (converging)
Constructive (diverging)
Conservative
What happens at a convergent plate boundary?
1) Oceanic plate slides beneath continental plate (subduction zone)
2) Rocks catch agaisnt each other as plates aren’t smooth
3) Ressure between plates builds
4) Plates slip past each other and may cause an earthquake
What is a subduction zone?
The place where to plates come together at convergent plate boundaries
What happens at a conservative plate boundary?
1) Plates slide past each other
2) Jagged edges catch agaisnt each other
3) Friction builds
4) Plates slip past each other and may cause an earthquake
What happens at a divergent plate boundary?
1) Plates more apart
2) Convection current causes a gap between plates which magma rises up to fill
What is a volcano?
An opening in Earth’s crsut that is formed when magma rises from inside the Earth
Where can volcanoes be formed?
Constructive and destructive plate margins
How do volcanoes form at convergent plate margins?
1) Denser oceanic plate is forced under continental plate
2) Friction causes cracks (vents) to form in continental plate
3) Magma rises to surface thrugh cracks
4) Creats highly explosive volcanoes that produce lots of gas and lava
Where do hotspots form?
Parts of Earth’s crust over hotter parts of the mantle
How do hotspots form?
Rising hot air from mantle weakens Earth’s crust and magma can reach the surface, bubbling through the weakness in the crust
What are the 2 main types of volcano?
Composite
Shield
What are features of composite volcanoes?
Found at convergent boundaries
Erput explosively
Andesitic lava (viscous)
What are features of shield volcanoes?
Found at divergent boundaries or hotspots
Not particularly explosive
Basaltic lava (not viscous
No ash produced
What 4 things can erupting volcanoes produce?
Lava (magma above surface)
Gases (sulfur)
Ash (tiny pieces of burnt rock fragments)
Pyroclastic flows (flows of hot ash, lava, gas)
What is an earthquake?
A sudden or violent movement within the Earth’s crust followed by a series of shocks
Where can earthquakes happen?
All 3 plate margins
How are earthquakes measured?
Using the moment magnitude scale
What is created when plates move past each other?
Vibrations
What are shock (seismic) waves
Energy released from the focus
Where does the most damage occur from earthquakes?
Where the seismic waves are the strongest, near the epicentre
What is the epicentre?
The point on the Earth’s crust directly above the centre of the Earthquake
What is an earthquake’s focus?
Where pressure is released underground and radiates out from
What are the 2 main types of earthquake?
Shallow-focus
Deep-focus
What are shallow-focus earthquakes?
Earthquakes where the focus is close to the Earth’s surface (0-70km)
What are deep-focus earthquakes?
Earthquakes where the focus is far away from the Earth’s surface (>70km)
What are features of deep-focus earthquakes?
Usually happen at convergent plate margins
Less damaging
Whare are features of underwater earthquakes?
Moves the seabed
Dispalces water and creates tsunamis
When did the Japan Eathquake hit?
11th March 2011
What magnitude was the Japan earthquake?
9.0
What were primary impacts of the Japan earthquake?
1 million buildings damaged
120,000 buildings destroyed
Many buildings sunk into the ground due to liquefaction
What were secondary impacts of the Japan earthquake?
Thousands of deaths
150,000 homeless
Damaged nuclear power station caused nucelar meltdown and no electricity
Destroyed railway lines
What are long-term impacts and responses of the Japan earthquake?
$200bn total damage
58% paid attention to tsunami warnings
5,000 aftershocks in the year after
When was the Kashmir earthquake?
8th October 2005
What magnitude was the Kashmir earthquake?
7.6
What were primary impacts of the Kashmir earthquake?
79,00 died
4 million homeless
Infrastructure damaged (water, electricity)
What were secondary impacts of the Kashmir earthquake?
Landslides destroyed towns
Sewage pipes broke spreading disease
Cold winter followed and froze homeless
What were immediate responses to the Kashmir earthquake?
Charities and foreign governments sent funds, air workers and helicopters
Warm clothes, tents given out
What were long term responses to the Kashmir earthquake?
Thousands relocated
Pakistan gvernment gave out money to rebuild homes
Thousands still lived in tents a decade later
Government changed building regulations
How does Japan predict earthquakes?
Seismic waves monitored by Japan Meterological Agency
Rapid warning system inroduced before 2011
How does Japan prepare for earthquakes?
Building regulations ensure shock absorber buildings
Bullet trains automatically stop
1st september is national earthquake day
How does Pakisatin predict earthquakes?
Upgraded systems to moitor seismic activity in 2005
How does Pakistan prepare for earthquakes?
Houses made of wood (less dangerous to collapse than concrete houses)
Poor infrastructure meant a lack of warning systems
What are lahars?
Mudflows generated as secondary effects of eruptions
