Hazardous Earth Flashcards
What two ways is heat redistributed globally?
Pressure difference (low and high pressure) and ocean currents (hot and cold water moving in different ways)
What causes pressure differences?
Heat creates zones of low pressure on land mostly ( land is easier to heat and quicker to cool so it makes the air is hotter and rises) and the sea creates zones of high pressure (absorbs a lot of heat and dose not give a lot of it off )
Which ocean current affects the UK’s climate and how?
The Gulf Stream begins in Mexico, blowing northeast where it branches towards Europe to become North Atlantic drift. It goes toward the UK creating an area of high pressure, unlike what it should be
What is the ITCZ?
A band of clouds, rain and occasional thunderstorms (low pressure). Follows the Sun to move around and causes wet and dry seasons.
What is in a high pressure zone and how is it caused?
The cold air sinks creating: No clouds Clear skies Heatwaves in summer Crisp clear frosty days in winter
What is in a low pressure zone and how is it caused?
The sun heats the ground, the warm air rises that contains water vapour and forms clouds. Then, the water vapor condenses to form precipitation
What is the global circulation model?
A theory that explains how the atmosphere operates in a series of 3 cells each side of the equator
Why is it hotter at the equator?
The Sun shines vertically there so the solar radiation is more concentrated in a smaller area resulting in it becoming hot rapidly.
What is the Hadley cell?
30 degrees either side of the equator. Low pressure at the equator but high pressure at 30 degrees
What is the Ferrel cell?
Between 30 and 60 degrees (only cell not caused by temperature)
What is the Polar cell?
Between 60 and 90 degrees. High pressure at 90 degrees and low pressure at 60 degrees
What were the past causes of global cooling?
Asteroid collisions- millions of tonnes of ash and dust enter the atmosphere and block sunlight for 5-10 years
Eruption theory- a large and explosive reaction gives off ash and sulphur dioxide; blocking sunlight for a short period
Orbital theory- oval shaped orbit causes cooling for a period as we are further away from the Sun (not as much as the other two)
What were the past causes of global warming?
Sunspot theory- sunspots are points on the Sun that are emitting more energy, so the more spots, the hotter the Earth for a long period
Orbital theory- at a point in elliptical orbit, we are closer to the Sun, causing and increase in heat
What is weather?
Daily changes in temperature, sunshine, wind direction etc
What is climate?
The pattern of weather over a longer period of time (usually 30 years)
What evidence is there for past climate change?
Ice cores- layers of ice that trap air containing CO2 for the year the ice was formed from snow
Tree rings- the thicker the ring for that year, the more CO2
Historical sources- paintings, diaries and records but these are often unreliable
Physical features- U shaped valleys etc
What gasses make up the air without human interference?
Nitrogen- 78.1%, carbon dioxide- 0.03%, oxygen- 20.9% and water vapour- 1%
What are the 4 main greenhouse gasses and their sources?
CO2- 89% and is found in fossil fuels, deforestation, factory fumes and wats
Methane- 7% and is found in rice farming, gas pipe leaks, cattle farmers and geysers
Nitrous oxide- 3% and is found in fumes from transport and fertiliser from agriculture
Halocarbons- 1% and is found in hair spray cans, deodorant cans and cleaning products
What is the human enhanced greenhouse effect?
The impact on the climate due to human activity creating increased amounts of greenhouse gasses, therefore creating additional heat
What evidence is there for current global warming?
Fossil fuels emitting greenhouse gases, CO2 and Methan at their highest levels, arctic sea ice shrinking by 10% and over 90% of the world’s valley glaciers are melting/shrinking
What future predictions are there for the climate?
More frequent extreme weather like floods, droughts and heat waves
Europe will experience less tourism due to winter snow
Crop yields will increase in countries further away from the equator
Traditional way of life will be losses as sea ice melts and temperatures increase in arctic regions
Huge loss of biodiversity
Coastal areas being lost or flooding often and areas becoming too hot inhabit
What are cyclones?
A rotating system of clouds and storms that from and develop over tropical and subtropical waters
Why are predictions for global temperatures uncertain?
Uncertain population growth, lack of knowledge about natural processes that occur which effect climate and the willingness for people to switch to more renewable energy sources
What happens in a hurricane/cyclone/typhoon
Intense rainfall- not usual for 1000mm of rain to fall in a single storm
Strong winds- whip up objects / vehicles or even take down a whole building
Storm surges- flooding usually caused by unusually high tides (created because there is less air on top of the water)
Landslides- movements of rock, debris and earth downhill, typically when the ground is saturated by rain causing it to slump
What three conditions are required for cyclones to form?
A large, warm still ocean- surface temperature needs to exceed 26.5 over a long period of time. Strong winds (118km/h) in the troposphere, 10-12km above the Earth’s surface (needed to draw up warm air rapidly from the ocean’s surface) A strong force caused by the Earth’s rotation known as the Coriolis effect (can only form 5-30 degrees either side of the equator)
When and why do cyclones decay?
On land due to lack of warm water sources.
What are the 5 stages of a cyclone formation?
Warm air currents rise from the ocean
Up currents of air hold large volumes of water which condenses to form clouds
Coriolis effect causes the rising current of air to spiral, making it cool, and descend to form the eye of the cyclone
As the cyclone moves away from the ocean, it’s fed with more heat and moisture, making it grow
It then reaches land where it losses a lot of energy, air pressure rises as temperature falls, winds drop, rainfall decreases and decays to a mere storm
Where was Hurricane Katrina?
Formed in the Atlantic
Went from a 2 to a 5 due to the Gulf of Mexico feeding it more hot water
Went through Florida as a 2 but met the Gulf of Mexico, became a 5 and then going through New Orleans, it was a 4
What key facts are there for Hurricane Katrina?
24th - 30th August 2005
80% of New Orleans flooded due to levees breaking
90000 miles squared affected
It hit land at 6 am so people were unprepared
Levees broke in 20 places
What were the social impacts of Hurricane Katrina?
1 million people displaced
1836 people died
300000 homes were destroyed
3 million left with no electricity
What were the economic impacts of Hurricane Katrina?
$110 billion worth of damage $300 billion worth of damages including secondary damages Oil platforms destroyed Shops looted Tourism decreased Fuel price increased
What were the environmental impacts of Hurricane Katrina?
Storm surges flooded large areas of the coast
Sugar cane and cotton plants were destroyed
Delicate coastal habitats were destroyed
What were the responses to Hurricane Katrina?
Awareness of hurricanes has increased Building requirements are stricter Defences like levees were improved to withstand higher categories of hurricanes $50 billion given as aid by government National Guard mobilised
What is a primary effect?
Things that happen instantly
What is a secondary effect?
Things that happen in hours, days and weeks after the initial hazard
Where was Cyclone Aila?
Formed in the Indian Ocean
Bay of Bengal
Asia, affecting mostly Bangladesh, some of Nepal and India
What were the key facts of Cyclone Aila?
Bangladesh had no computers to plot all the data
21st - 22nd May 2009 (formed)
23rd May 2009 (hit Bangladesh at a category 1 cyclone with winds of 120km/h)
What were the social impacts of Cyclone Aila?
Flooding and winds left over 750000 people homeless
200 deaths
No sanitation which led to an outbreak of diarrhoea only a week after the cyclone hit
3.5 million people affected
Sickness, typhoid and malaria
What were the environmental impacts of Cyclone Aila?
Loss of animals caused a loss of animal dung being used as a fuel source, resulting in pressure of firewood sources
The endangered Bengal Tiger was affected, with 30 being killed
What were the economical impacts of Cyclone Aila?
Crops covered in saltwater died
$550 million worth in damages
Due to lack of skills, people had to take labouring jobs
What is vunerability?
A measure of the extent to which a community or area is likely to be damaged or disrupted by the impact of a hazard
What is a risk?
The probability a hazard will cause harmful consequences
What are the factors affecting vulnerability?
Preparation- some hazards are easier to predict like flooding and drought
Population density- urban areas= more deaths / rural areas= less deaths
Building design- secure, flat land > steep, unstable hills
Time of day- people may not be awake so there would be more deaths
Economy- wealthier people tend to lose more money due to their valuable properties
Education- learn how to reduce and avoid the impacts of hazards
What methods does the USA (a developed country) use to respond to hurricanes?
Weather forecasting- frequent, accessible but system isn’t up to date, people don’t always follow advice
Satellites- help to predict and track hazard but predictions are broad and sometimes, incorrect
Warning systems and evacuation strategies- risk services mean emergency services don’t become overwhelmed but zones aren’t always accurate
Storm surge defences- saves money on property and insurance with cheaper options but aren’t always reliable and goverment isn’t able to maintain them
What methods does Bangladesh (a developing country) use to respond to a cyclone?
Weather forecasting- warning over TV and radio, results in fewer deaths, not as accessible in rural areas
Satellite- US’s, China’s and Japan’s shared satellite currently, developing their own, expensive and takes time to build
Warning systems- early warning, allows coastal communities to evacuate, time consuming and expensive
Evacuation strategies- 3500 shelters, death rate is doubled without them, more still needed and are costly
Storm surge defences- embankments, protection against flooding, doesn’t protect the whole country and can fail
Where are rainforests located?
Around 0 degrees due to the area of low pressure causing rainfall
Where are deserts located?
At areas of high pressure, such as 30 degrees
What are the key components of the Earth?
The inner core, the outer core, the lower mantle, the upper mantle and crust
What order does the components of the Earth go in?
Crust (continental then oceanic), lithosphere, asthenosphere (upper mantle), lower mantle, outer core and then the inner core
What are the features of the crust?
50 km thick (0-70 km thick in some parts) and can be continental or oceanic
What are the features of the mantle?
2900 km thick, made of molten rock/magma
What are the features of the outer core?
2266 km thick, 4700-5700 degrees and is made of liquid iron and nickel
What are the features of the inner core?
Diameter of 1200 km, 5700 degrees and mostly solid iron and nickel
What is the lithosphere like?
It is cool and brittle as well as being the closest part to the crust
What is the asthenosphere like?
Hot, semi-molten, viscous, quicker and lies beneath the tectonic plates
What is radioactive decay?
50% of the Earth’s heat caused by elements in the Earth
Why is the Earth’s crust unstable?
Heat source from the core
Convection current happen in the outer core
Heated rock from the mantle rises
Heat moves towards the surface creating magma plumes
Semi-molten rock spreads out carrying the tectonic plate
Magma cools down and shrinks
This cycle continues
What evidence is there for continental drift?
Some continents appear to fit together like a jigsaw and fossils from the same animal found in two different continents.
What are the features of continental crust?
Made of thick granite, has a lower density than the basalt of oceanic crust, floats on the mantle and it forms the land
What are the features of oceanic crust?
Very thin basalt and is denser than the granite therefore, it is bellow the sea
What are the features of a divergent plate boundary?
Between two oceanic crusts, they move away from each other, earthquakes tend to be gentle and volcanoes aren’t as violent but more constant
What are the features of a convergent plate boundary?
Between an oceanic and continental plate boundary, towards each other (one goes under the other), earthquakes are caused by pressure between the two plate boundaries, fold mountains and volcanoes are formed
What are the features of a collision plate boundary?
Between two continental plates, they collide and big earthquakes are formed by a massive build up of friction and pressure
What re the features of a conservative plate boundary?
Between two continental plates, moving alongside each other and massive earthquakes are caused due to the build up in pressure
What is a hotspot volcano?
Where in the center of a plate, magma rises. This causes the lithosphere to melt and magma pushes through the crust to form a volcano.
What are the features of a composite volcano?
Layers of ash and lava layered on top of each other to form a cone shaped peak
Violent eruptions with landslides, poisonous steam/ ash is ejected into the sky and rock bombs
Thick, slow lava (pyroclastic flow) that runs down the slope
Happens at convergent plate boundaries
What are the features of shield volcanoes?
Broader, wider peaks that covers a larger area
Runny lava that flows down the gentle slope quickly
Happens at a divergent plate boundary
What is the epicentre?
The point on the Earth’s surface above the focus (above the crust as well)
What is the focus?
The point in the crust where the most pressure and tension is being released (inside of the crust)
What are seismic waves?
The earthquake’s energy being released
What is happening at a convergent plate boundary when an earthquake is taking place?
The movement of the tectonic plates (oceanic and continental) creates friction which builds up and plate boundaries move against each other until the energy is released.
Energy is sent out in shockwaves
Fractures in the crust between the two plates are concentrated along the fault line
What is the Richter scale?
A scale that measures the strength/ magnitude of earthquakes. It is logarithmic meaning it goes up in x10 each level
What is seismometer?
It is a device that measures and records seismic waves
How is a tsunami formed?
An earthquake is caused underwater
Seismic waves spread quickly outward
Sea above earthquake forced upwards
Sea movement causes tsunami
What is the key information about the Haiti earthquake?
12th January 2010 at 4:53 pm
Magnitude 7
Conservative plate boundary (two continental)
The epicentre was 25 km from the capital (Port-Au-Price)
What caused so many deaths during the Haiti earthquake?
The buildings collapsed and fell on people as well as a cholera outbreak
What were the primary effects of the Haiti earthquake?
230000 dead
300000 injured
250000 dwellings destroyed or badly damaged
Infrastructure completely destroyed (government buildings, hospitals, roads and electricity)
What were the secondary effects of the Haiti earthquake?
Cholera outbreak due to poor sanitation
Airports unusable
Mass graves dug
1 in 5 jobs lost
What were the immediate responses to the Haiti earthquake?
Delays caused anger, looting and sporadic violence
Mass graves were dug
People attempted to save other
Supplies were given to limit the spread of disease
What were the longer term responses of the Haiti earthquake?
4.3 million provided food rations
Water and sanitation provided for 1.7 million
$430 million donated as aid
What is the key information about the Japan earthquake?
11th March 2011 at 2:45 pm
Happened on the east coast of Japan with the nearest town being Sendai
There was already a 7.2 earthquake on the 9th
The tsunami was travelling at speeds of 500 mph
Buildings were already built to be earthquake proof
40% of Japan’s coastline had sea walls up to 10 metres
What were the primary effects of the Japan earthquake?
More than 1700 people dead or missing with many unaccounted for (9500 people in a single town)
4 million without electricity
A million with no water
What were the secondary effects of the Japan earthquake?
Radiation leaks from a damaged nuclear plant
3 workers suffered radiation poisoning
215000 live£ in government housing
$15 billion in insured damages
What were the immediate responses for the Japan earthquake?
Warnings
Specially trained groups sent as aid by the government
NGOs and other aid agencies donated $1 billion as aid
340000 people were displaced and given required supplies
What were the longer term responses of the Japan earthquake?
6 days after the earthquake, the motorway was repaired
What is the greenhouse effect?
The incoming shortwave radiation from the Sun and the outgoing long wave radiation into space. The greenhouse gases trap the some long wave radiation and the rest is lost into space.
Where are arid climate zones and what are they like?
Sinking air from the Hadley and Ferrel cells meeting causes high pressure and prevents rainfall with hot temperatures
Where are tropical climate zones and what are they like?
Rising air from the two Hadley cells meeting causes low pressure and lots of rainfall. Temperatures are hot because it’s on the equator but rainfall remains constant.
Where are polar climate zones and what are they like?
Sinking air from polar cells creates an area of high pressure at the poles. Temperatures are low all year round and there’s little rainfall.
