Restless Earth

Restless Earth

1. Plate Tectonics

   • There are two type of crusts
     • Oceanic crust
       • Newer- most less than 200 million years old
       • Denser
       • Can sink
       • Can be renewed and destroyed
     • Continental Crust
       • Older- most over 1500 million years old
       • Less dense
       • Cannot sink
       • Cannot be renewed or destroyed
   • Destructive Margin
     • Ocean crust sinks under the continental crust. The ocean crust melts in the mantle what increases the pressure.
     • An example of the plates is the Nazca (oc) and the south America (cont)
     • The features at these plate margins are a composite volcanic eruption, Earthquakes, Ocean trenches, Fold mountains and a tsunamis
     • An example of a destructive margin is Andes (Ring of Fire)
   • Constructive Plate Margin
     • Two plates move apart from each other allowing magma to rise to the surface from the mantle and creates shield volcanoes and sometimes weak earthquakes.
     • An example of the plates are North America (cont) and Eurasian (cont)
     • The features of a constructive margin is a Shield Volcano eruption and minor earthquakes
     • An example of a constructive plate margin is the Midi Atlantic Ridge (Iceland)
   • Conservation Plate Margin
     • Two plates slide past each other but they get caught and pressure builds up as they try to pull apart. and when they do break free they create a huge earthquake
     • An example of the plates are the Pacific and North American plates
     • The features of a conservation plate margin are major earthquakes
     • An example of a conservation plate margin is San Andreas Fault Line (L.A)
   • Collision Plate Margin
     • When two continental plates collide together and they fold upward to create a mountain range.
     • An example of the plates are the African Plate and the Eurasian Plate
     • The features of a collision plate margin are fold mountain ranges and earthquakes
     • An example of a collision plate margin is The Himalayas
   • Landforms at a collision margin and a Destructive Margin
     • A collision margin is made up of two continental plates what are both moving towards each other. The mountains are made because of a geosyncline (what is a depression in the earths crust) this will have rivers running into it, sediments settle on the bottom. As the plates move towards each other it compress the sediments and turns it to rock and eventually sediment will fold and become fold mountains and because plates have pushed the sediments up into the mountains it will have a pattern were there are anticline and syncline where they go up and down.
     • Ocean Trenches are formed at a destructive margin they can be up to 11,035 meters below sea level

2. Human Activity in fold mountains

   • Alps
     • Were created 35 million years ago
     • They spread over the country's of Italy, France, Switzerland, Austria and Slovenia
     • They are 4810 metres above sea level
     • There highest mountain is Mount Blanc
     • It is on a collision margin
   • 1. Farming
     • Cattle, Sheep, crops (graphs/apples)
     • They farm on the south facing slope
     • The farms are on the valley
     • Transhumance-is the movement of animals you have to make your animals have down the mountain when it gets colder
   • 2. Tourism
     • Winter- Snowsports
     • Summer-Walking, Mountain bikes, Cycling and climbing
     • Local business do well due to the tourism
   • 3. Energy
     • Steep sided mountains
     • Narrow Valleys
     • Easy to make a dam
     • Hydro-electric power (HEP)
     • High precipitation (snow melting)
   • 4) Industry
     • Logging
     • Paper, Fuel, Conifers
     • Coniferous Trees
     • Salt (Gold/ Iron ore/ Silver and Copper)

3. Volcanoes

   • A volcano is an opening or vent in the earths surface through which moltens material erupts and solidifies as lava
   • Key word of Volcanoes
     • Main vent- This the pipe up the middle of the volcano
     • Magma chamber- This is the source of the molten rock
     • Crater- This is the depression at the top of the vent
     • Parasitic cone- This the secondary cone forming on the side of a volcano
     • Volcano bombs- This is airborne materails from the volcano ash and gas clouds
     • Lahar- A lahar is a mudflow created when snow melt and mixes together with ash.
     • Pyroclastic flow- Is hot dust that races down the volcano at 350mph
     • Hot spot volcano is found at a weak spot in a plate e.g. Hawii
   • Shield Volcano
     • A shield volcano is formed as the plates move apart, magma rises upwards from the mantle to fill the gap. This adds new rock to the spreading plates. Some of the magma may also be forced out to the surface through the vent. Some volcanoes grow high enough to form volcanic islands.
     • The characteristics of a Shield Volcano
       • Has Basic lava
       • Cone with wide base and gentle slopes
       • Made of lava only
       • Regular and frequent eruptions
       • Lava pours out with little violence
     • Examples are Hekla and Surtsey in Iceland and Mauna Loa and Kilauea in Hawaii
   • Composite cone Volcano
     • When the plates collide, the denser oceanic plate is pushed down into the mantle. Here the plate melts and is destroyed in the subducted zone. In the subduction zone the plate form a pool of magma. The greatest heatand pressure may force the magma along a crack where it erupts at the surface to build up a volcano.
     • The characteristics of a Composite cone volcano
       • Has acid lava
       • Tall cone with narrow base and steep side
       • Made of alternate layers of lava and ash
       • Irregular eruptions with long dormant periods
       • Violent eruptions with explosions possible
     • Examples are Mount Etna, Mount Vesuvius and Stromboli in Italy and Krakatoa in Indonesia
   • Volacic eruptions MEDC
     • Mount Saint Helens
       • Facts
         • It is located in Washington State about 55 miles northeast from Portland, Oregon and 95 miles south of Seattle Washington.
         • Mount Saint Helens is a volcano in the Cascade Mountains
         • The volacanic ash cloud drifted eastward in 3 days and encircled the Earth in 15 days
         • Washinton State workers had to remove 900,000 tons of ash from highways and roads.
         • The damage covered 230 square miles
         • Mount Saint Helens was 9,677 ft high but after the eruption it was 8,477 ft high
       • Primary Effects
         • Pyroclastic flow, 300mph, 350 degrees C, 230 sq miles of forest habitat destroyed and 7000 animals killed
         • 390 metres lost off volcano, 1/2 billion tonnes of ash 15 miles high polluting the atmosphere, 10 metre deep in rivers, 12 million salmon killed
         • Snow melt, 90mp Lahar/Mudflow 200 m thick destroyed habitats, 250 homes and57 deaths
       • Secondary Effect
         • Ash cloud over 3 states deposits 40 miles away caused traffic accidents (5 deaths), 5000 motorists trapped and electric failure as ash broke power lines.
         • 'seared zone' every tree 230 sq miles forest destroyed (9.4mm3 timber) resulting in important indudtry lost
         • Lahar 200m deep, 14 million m3 debris, removing bridges, blocked harbour.
       • Immediate Respounce
         • Scientists monitoring
         • Exclusion zone 12 miles
         • Evacuation of residents
       • Long Term Respounce
         • State of emergency PORTLAND
         • Air ports eastern Washington closed and motorway due to ash
         • US army takes 18 months to dig out Toutle river

4. Super Volcanoes

   • Super volcanoes are different to normal volcanoes as they are not found in a linear pattern and are not found plate boundarys like normal ones are instead they are found in hotspots a weak spot in a plate and there are only 7 known super volcano for example Yellowstone and Lake Toba.
   • 1) Rising magma cannot escape and a large bulge appears on the surface
   • 2) Cracks appear in the surface and gas and ash erupt from magma chamber
   • 3) The magma chamber collapses forming a depression called a Caldera
   • Yellow Stone
     • Yellow stone is located in USA in North American plate and it is on a hot spot
     • Local Effects
       • 90% death toll in a 100km=500,000
       • Power lines break
       • Pyroclastic flow what goes on for 80km
     • National Effects
       • Possible Nuclear Meltdown as rivers clogged with ash and power stations will over heat, radiation.
       • Air, road and rail communication lost
       • 1000 KM 90% dead
     • Global Effects
       • 3 to 4 days before ash is in Europe
       • Monsoon rains in Asia stop leading to drought and Famine
       • Climate change- Mini Ice age due to a drop by 12 degrees this could uses to human extinction

5. Earthquakes

   • Earthquakes are vibrations most are caused by earth movements at a plate boundaries and at major fault lines (cracks in the earth's surface).
   • Most of the earthquakes are found in a liner pattern for example the Pacific and South American. Most earthquakes happen because they are at a plate margin like a destructive and collision margin. As the plates move friction build up, a Earthquake is a release of friction what causes vibrations.
   • Measurement of Earthquakes
     • Richer scale
       • Goes up by 10
       • Magnitude is how powerful
       • 9
       • 8*10
       • 7*10
       • 6*10
       • 5*10
       • 4*10
       • 3*10
       • 2*10
       • 1*10
       • 0*10
     • Mercalli scale
       • Roman Nurmerals
         • Access the damage= a level
       • Max XII
       • Not Scientific
   • The focus is a the centre of the Earthquake underground
   • The epicentre is the centre of an earthquakes on the ground surface.
   • Earthquakes case studys
     • MEDC
       • KOBE
         • Facts
           • KOBE, Japan 7.3 RS
           • 1995
           • Pacific- Eurasian
           • Destructive plate margin
         • Primary Effect
           • Liquefaction on 60 square miles reclaimed land.
           • 6,434 deaths and 40,000 injured
           • 10% of infrastructure destroyed including road, rail, gas and electric
         • Secondary Effect
           • 300,000 homeless refugees
           • 2 million had no electricity for 10 days
           • Loss of industry e.g. Panosonic
         • Immediate Response
           • Motorola let every one have free phone connection
           • Assessment of building and demolition
           • 7 eleven provided essentials
         • Long Term Response
           • Building built to modern safety standard e.g. spaced apart to prevent domino, flexible steel frames and shock absorbers
           • Cost $220 million to repair roads and railways up to 80% in a month
           • Practise drill on anniversary of KOBE to educate and Rainbow house was opened
     • LEDC
       • Nepal
         • Facts
           • Nepal 7.5 RS
           • 2015
           • Eurasian-Indo autralian
           • Collision
         • Primary Effects
           • UNESCO is a world Heritage sites what was destroyed in Kathmandu Durbar square
           • 9000 killed and 2300 injured
           • Avalanche on MT Everest 19 deaths at base camp, huge block sof ice within blast, climbers at camp 1 cut off from Basecamp
         • Secondary Effect
           • Over 8 million people have been affected
           • 450,000 homeless
           • 29% of children underweight (3 month after)
         • Immediate Responce
           • Nepal declined international help
           • Human chain to move rubble
           • Hospitals spills onto street
         • Long Term Response
           • International rescue Denmark, USA, Australia, China and India
           • Crisis mapping used with the help of satellite and drones to organise relief..
           • Red Cross support using heartbeat dectors
         • An immediate response was that the local people made up of men, women, boys and girls of all ages all formed human chains. The chain was to remove rubble from areas of supposed trapped people mainly in the city of Kathmandu. Then passed material along the chain in a rather disorganised way and put the rubble in a designated area elsewhere. This was a good response because it was freeing trapped people immediately allowing urgent medical care to treat them. This was a bad response because they weren't organised in their response, it was not targeting a key area of trapped people and could be wasted valuable time.
         • A long term response was the modern use of technology. Charitable groups from USA and UK brought drones with them with cameras attached. They could fly over parts of Nepal and observe and map where there was total devastation or partial destruction. This is called crisis mapping and prioritises where help should be sent. This is good because aid can be targeting to certain areas that need it rather than guessing, helping people who desperately need aid. This is bad because hep may be too late and people in need of aid may expect help rather than a drone hovering overhead.

6. How can hazard dangers (volcanoes and Earthquakes) be reduced

   • Volcanoes
     • Plan
       • Prepare an evacuation and organise transport for the people who need to go and take food as well.
       • Warning system
     • Predict
       • An increase in earthquake suggest magma is rising beneath the volcano and it might erupt
       • Tiltmeter will measure changes in the ground
       • Digital cameras are placed on the crater to record small eruptions
       • Drones
       • GPS
     • Protect
       • Concrete Barries
       • Exclusive zone
   • Earthquake
     • Predict
       • Hazard map
       • Frequency graph
       • Tiltmeter
       • Laser Beams
       • Siesometer wave
       • Animal behaviour
     • Plan
       • Practise drills
       • Training
       • Warning system
       • Building resistant
     • Protect
       • Shock absorers
       • Flexible frame
       • Bird cage
       • Fire resistance

7. Why people do not move away from these areas

   • LEDC
     • Too poor to move
     • The agriculture
     • Family live there
     • Your home is there
   • MEDC
     • Building Regulation
     • Warnings
     • They feel safe
     • Money to apply tech
     • Jobs, climate, lifestyle

8. Tsunami

   • Japan Tsunami
     • Facts
       • It happened at Sendai, Japan in 2011
       • Plates what cause the tsunami were Pacific and the Eurasian plates what is a destructive margin.
     • Primary Effects
       • The National Police Agency has confirmed 15,889, 6,152 injured and 2,601 people missing
       • Within 24 minutes the tsunami was 10 metres high, and was travelling 15 km inland.
       • Building swayed for 5 minutes
       • Gas pipes breaks a fires rage
     • Secondary Effects
       • 500,000 people were made homeless
       • Nuclear power plant at Fujkashima over heated and exploded what will cause long term contamination. 167 workers dosed with radiation and 156,000 displaced from there homes.
       • Japan stock market decline due to loss in trade what caused them to loss $47 billion.
     • Immediate Responce
       • Early warning system to evacuate
       • japan army (100,000) search using infra red cameras
       • They made a 60km evacuated around the nuclear power plant.
       • They build new tsunami walls what were 12m high
     • Long Term Responce
       • Scientific research into Earthquakes and tsunamis
       • Infra structure prioritised to rebuild