GCSE Geography AQA - Restless Earth

These are revision cards for GCSE geography AQA, I'm making ones for restless earth, the coastal zone, rocks, tourism, population and urban. In some parts its hard to describe processes without pictures, so just try to imagine it! These include case studies :)

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Structure of the Earth

Continental Crust:

  •  30 - 50km thick
  • Over 1500 mil years old
  • Mainly granite, silicon, O2, aluminium
  • Can't sink, can't be destroyed, 2.6 density

Oceanic Crust:

  • 6 - 10km thick
  • Less than 200 mil years old
  • Mainly bascut, silicon, magnesium, O2
  • Can sink, can be destroyed, 3.0 density

Inner core < outer core < mantle < oceanic crust < continental crust

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Plate Margins

  • Constructive plate margins - 2 plates move away from each other, magma rises to surface to form volcanic islands, volcanoes & earthquakes
  • Collision zones - 2 cont. plates move towards each other, neither can be destroyed so form fold mountains, no volcanoes but some earthquakes
  • Destructive plate margins/subduction zones - 2 plates move towards each other, heavier oceanic crust sinks below cont. crust, causes deep sea trenches, volcanoes & earthquakes
  • Conservative plate margins - 2 plates move sideways next to each other, same direction or different directions, violent earthquakes
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Fold Mountains & Ocean Trenches

Fold mountains:

  • many places e.g. Alps, Himalayas, Carcasas
  • Rivers carry sediment into sea between 2 plates, sediments build on sea bed
  • Geosycline  filled with sediment, compression as plates move towards each other
  • Continued compression from 2 plates, sediments folded into fold mountains

Ocean trenches:

  • found in subduction zones, edge of Pacific ocean e.g. Peru-Chile trench
  • Oceanic plate sinks below cont. crust, causes a trench
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Shield & Composite Volcanoes

Volcanoes found in long narrow belts e.g. 'Pacific Ring of Fire' & mid Atlantic ocean, south Europe & centre of Pacific ocean

Shield volcanoes:

  • Constructive plate margins
  • Lava - runny, basic, hot
  • Cone - wide base, gentle slopes made of lava
  • e.g. Mauna Loa, Hawaii; Hekla & Heimaey, Iceland

Composite volcanoes:

  • Destructive plate margins
  • Lava - acidic, sets quickly
  • Cone - tall, narrow base, steep sides made of layers of lava & ash
  • Pyroclastic flows, secondary cones
  • e.g. Mt St Helens, USA; Pinatubo, Philippines
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Earthquakes

  • Caused by sudden release of pressure due to movement along faults
  • Most occur along plate margins, strongest at destructive, constructive & conservative
  • Plates suddenly lurch, point where pressure is released called the focus
  • At destructive plate margins focus is deep & sinking of subducting plate & its subsequent melting can trigger strong earthquakes
  • Longitudinal & transverse waves, surface of focus called the epicentre
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Plate Margin Case Studies

  • Constructive - Mid-Atlantic Ridge, Iceland
  • Destructive/subduction - Nazca & South American plate boundaries, Andes mountains (fold mountains), Peru-Chile Trench (8km deep, 45,00km long from Panama to Tierra del Fuego) 
  • Collision - Indo-Australian & Eurasian plate boundaries, Himalayas
  • Conservative - Pacific plate (faster) & North American plate (slower), San Andreas Fault
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Fold Mountains - The Alps

  • Why is human activity hard? - relief high & steep, accessibility hard; narrow mountain valleys, making roads/railways hard; soil is stony, thin & infertile; colder, windier & wetter as you go up

Human activity:

  • Forests - timber from coniferous forests main building material & winter fuel, pulp & paper
  • Farming - on south-facing slopes are warmer, transhumance - seasonal movement of animals, summer cattle on higher alp, fodder grows on valley floor, winter cattle to valley floor, feed on fodder; new techology - cable cars carry milk to valley floor, turn milk into butter & cheese
  • HEP - Hydro-electric Power, power generated from fast-moving rivers due to steep slopes, precipitation & melting glaciers; cheap, renewable, used by sawmills etc, supplies with electricity
  • Tourism - skiing, snowboarding, e.g. St Montz Chomonix; glacial lakes, scenery e.g. Interlaken
  • Safety - building tunnels & shelters along roads from avalanches, expensive, needs technology
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Mount Pinatubo

  • 9th June 1991, not erupted since 1380; largest eruption of 20C, near city of Manila, destructive plate margin; Philippines plate (oceanic) & Eurasian plate (cont.)
  • Primary effects - 200,000 homes destroyed, local hospital, schools & factories, contaminated water, unusable roads & bridges, ash ruined harvest of 1991, 6 died as direct result of eruption
  • Secondary effects - planting in 1992 impossible, over 1 mil animals died, farmers forced to city, disease like malara & diarrhoea, 1991 & 1993 monsoon rains - flooding & lahars, lowered world temps & blocked sun, 700 died from disease/lahars
  • Immediate responses - many didn't believe it would happen, fled with panic to refugee camps, emergency aid from Japan - food, medicine, blankets, April - June 1991 early warning signs, evacuation of 58,000, 15,000 at Clark Air Base
  • Long term responses - Nov 1991 US abandoned CAB, Aeta tribe returned to slopes, Japan granted materials for rehabilitation, people from Angeles stayed in refugee camps due to lahars, 10 years later CAB now a thriving tourist resort, 1993 Clark Development Corporation for Aeta, 7 industries
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Pinatubo - predicting & preparing

Predicting:

  • Magma moving causes small earthquakes, measure using seismomenters, recorded 2 months before eruption
  • Ground temps increased - heat seeking cameras
  • Bulging lava dome - tiltmeasures by CAB
  • Gurgling magma, gas & steam
  • GPS - detect movement

Preparing

  • Forecast eruption, predict how powerful it will be
  • Evacuate those in danger area, provide transport, accommodation & food
  • Train more emergency service teams
  • 2nd April, first evacuation of 2,000 people
  • Organise emergency supplies & water
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Yellowstone Supervolcano

Supervolcano characteristics:

  • erupts at least 1000km3 of material
  • formed by boiling reservoir of magma, grows to enormouse size & colossal pressure
  • when it erupts & collapses, it causes a huge depession called a caldera

Facts: north-west Wyoming, USA; 55km by 65km; recurrence interval of 600,000 years; geysers, mud pits & hot springs; ground risen by 70cm in some places

Local effects - devastating for 100 mile radius; pyroclastic flows for 50-100 miles at 500 mph; ash rise 80,000 feet, then 20-30 feet would fall; 400,000 people at risk; inhaling ash is dangerous; animals & crops die; day turns to night

National effects - north-west USA devastated; ash particles stay in air for years, crops fail for 6 years, biggest supplier of grain so big consequences

International effects - severe air traffic disruption; global temps & climates effected; ash particles in air for 6 years

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Kobe Earthquake

Location - epicentre on Awaji Island in Osaka Bay off coast of Kobe, south Japan

Magnitude & duration - Philippine plate under Eurasian plate along Nokima fault, 7.2 Richter scale, 20 seconds

Date & time - Jan 17th 1995, 5:46 am

Primary effects - 200,000 buildings destroyed; bullet train bridges collapsed; 120/150 quays destroyed; 1km of Hanshin Expressway collapsed; almost every house flattened

Secondary effects - electricity, water, gas supplies cut off; fires; massive traffic jams help up emergency crews; 230,000 homeless; Panasonic & Mitsubshi temporarily closed; 5,500 dead & 40,000 injured

Immediate responses - Hanshin Expressway still closed; hospitals struggled to cate for everyone

Long term responses - all services working by July; fire areas by Aug; total damage £56 bn, Sept 1996 H. Expressway open again, buildings further apart, flexible steel frames, rubber blocks 

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Sichuan Earthquake

Location - Sichuan country, central China, epicentre in Wenchuan

Magnitude & duration - Indian Plate & Eurasian plate along Longmenshan fault; 7.9 Richter scale, 120 seconds

Date & time - May 12th 2008 at 2:28 pm

Primary effects - 8,700 dead initially, 374,000 injured; 5-10 mil homeless; 5 million buildings collapsed, Juyuan school in Dujiangyuan 900 pupils killed; communications stopped

Secondary effects - 69,000 dead, 18,000 missing; landslides blocked roads & rivers; fear of flooding; £75 bn damage

Immediate responses - 20 helicopters bring relief & rescue; army troops parachuted & hiked to worst areas; clean water, food supplies & tents

Long term responses - teams from Japan, Russia & South Korea helped; donation of £100 mil from Red Cross, went to running camps

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Indian Ocean Tsunami

Location - epicentre in Sumatra

Magnitude - 9.1 Richter scale, 10m vertical displacement of seabed along 750 mile fault line

Date - 26 Dec 2004

Effects - highest wave 25m; 220,000 died, 650,000 injured; 2 mil homeless; tourist resorts damaged, affected local economy, many foriegn nationals died

Responses - rescue services & emergency teams swamped by scale of disaster; wounds turned gangerous; fresh water, water purification tablets, food, sheeting & tents from whole world; £75 million from UK, build 20,000 new homes; Indian Ocean Tsunami Warning System set up in June 2006

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Comments

elllieeeeeeeee

these are really good!:') im doing wjec but most of the above is the same!:D

thankyouu!

<3

Jenny Hoper

thats ok! good luck:)

Jenny Hoper

yes its for higher but I think most foundation is on this

shahrukh

ty , i have an exam on thursday :)

Jenny Hoper

me too :)

megan

is this everything that we need to know for AQA Higher Geography for Thursdays Exam on Restless Earth? The notes just seem quite few and for the notes i have already done of other topics which has been 10+ A4 pages i'm just really surprised xo

Vanessa

so helpful! thankyou very much:)

Vanessa

so helpful! thankyou very much:)

Jenny Hoper

basically yes, just in note form. I've tried to put the most important key words & figures for case studies etc, there isnt anything big missing but expand on these notes in the exam. I have proper A4 notes as well, these are just revision cards to remind me :)

megan

these notes are missing some quite key things, like the difference between volcanos and supervolcano etc

my friend and I have tried using these but then have had to do more ourselves. overall good notes and say msot things we need to know but are not full, so if anyone does use these be aware they are PROMPTS more than NOTES

Jimjim

Thanks m8 :)

Jenny Hoper

I made them according to the AQA syllabus, the difference between volcanoes & supervolcanoes wasn't there. They contain the most important information, hence why I said expand on them.

mia

Well i found these notes really helpful and they have all the key information! And It didn't ask the difference between the volcanoes anyway so I think that if you didn't find them helpful you should have made your own

Jenny Hoper

hahaha mia ;)

Princeeeee

you say that "plates move towards each other", which i take to mean 2 continental plates (destructive collision zone) and i was just wondering what the ocean is in this. Is it an oceanic plate being subducted beneath the two continentals or what? I am a bit confused with that.... Do I need to know the relevance of the ocean in this and is there an oceanic plate involved at all? P.S your notes are fab!! I bet you get an A*!!

Princeeeee

P.P.S the difference between super and normal volcanoes is in the syllabus, we learned it in class and also its in the text book. (Yellowstone.)

Princeeeee

what do you mean by "basic" lava?

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