Tectonic Landscapes

My revision notes for the first part of my re-sit.

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Earthquake: Causes

Turkey is being squeezed between three tectonic plates: the Eurasian, the African and the Arabian. This has created numerous faults or cracks on the Earth's surface. Izmit (the city on the Epicentre of the 1999 earthquake) is on the North Anatolian fault. The North Anatolian fault slipped between 2cm and 5cm thus causing the earthquake. The land underneath Izmit is made of soft clay and sand which moves easier than solid rock.

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Earthquake: Effects on People and Enviroment

18,000 people died as a result of the earthquake, mostly from falling buildings. 300,000 people were made homeless because their houses were destroyed. The motoway between Ankara and Istanbul buckled leading to cars crashing into each other and causing transport to be disrupted. The waste treatment plant at Petkim was damaged leading to raw sewage spilling into the rivers and killing fish. A 6m tidal wave struck Digirmendere causing costal erosion and damaging the town park. There was a chemical leakage from a chlorine factory in Yalova, making water undrinkable.

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Living near Volcaneos: Ecomonical and Social

By volcanoes, there is rich, vertile soil which is used for crop growing, so people can make money. E.g. Vineyards in Italy to make wine. Tourism is popular in volcanic areas so locals can get money through trips to volcaneos e.g. The Canary Islands. People also live near volcaneos because all their family live there and they are too poor to move away. Plus, there might be a low risk of eruption or the volcaneo might be dormant e.g. Mt Teide in Tenerife.

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Mercalli and Richter Scale

The Mercalli Scale is subjective, measured by people, is measured on a scale 1-12 and it measures the damage in one area. The Richter Scale is scientific, measured by Seismographs, the scale is infinant and it measures the magnitude of the earthquake. Most scientists use the Richter scale because it is more reliable.

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Volcaneo: Causes

Monserrat is situated on a destructive plate bountary. The North American plate is slowly being forced under (subducted) the Caribbean plate. This is because the oceanic North American plate is denser than the continental Caribbean plate. Convection currents pull the denser North American plate into the mantle where the heat causes the plate to melt. This molten rock is lighter then the surrounding rock, forcing it to rise towards the Earth's surface forming the volcanic island of Monserrat. On 25th June 1997, at one o'clock, Chances Peak volcaneo erupted catastrophically.

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Volcaneo: Effects on People and Enviroment

During the eruption 5 million cubic mertres of rock and ash were deposited, covering 4 square kilometres of land. The pyroclastic flows broke and flattened thousands of trees. Vegetable beds were bare of plants and the soil was baked hard. The pyroclastic flows extended westwards causing the Belham River to flood. Nineteen people, mostly farmers were killed by the pyroclastic flows. 100-150 houses were destroyed, they were partially buried or burned by the intense heat.

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How are volcaneos formed at Convergent plate bound

At this plate boundary, an oceanic and continental plate are pushed due to convection currents in the mantle. As the oceanic plate is denser, it subducts into the mantle where it begins to melt. A deep ocean trench is often formed and fold mountains are formed as the land is buckled. The motlen rock is then forced though the gap and erupts on the Earth's surface as a volcaneo. E.g. Andes

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Epicentre and Focus shtuff

Focus:
A point below the ground.
The depth below ground can vary.
Shockwaves radiate out from here.
Where crustal tension is released.

Epicentre:
A point on the surface.
Area of greatest destruction.
Visible sign of earthquake.

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Prediction and Prevention: Volcaneo

Scientics analyse the gases coming out of the vents to see if the volcaneo is ready to erupt. Remote sensing satellites record changes in the shape of the volcaneo. At Monserrat (25 June 1997) the Chances Peak volcaneo erupted. There were exclusion zones made to limit the amount of people becoming affected my the volcaneo. People were educated and told to leave the exclusion zones if a Siren sounded, this was also to reduce fatalities. Other ways to reduce damage are to build barriers to divert the flow of lava away from villages and towns. Diversion channels were created also to divert lava flow away from populated areas. And lava flow can be cooled by spraying water on the to slow them down, giving people a chance to evacuate.

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Living near Earthquakes

People live near places with earthquake activity because places like Japan educate people and provide a disaster planto avoid casualties. Turkey is a popular tourist area which provides jobs for locals which gives them money. Place that are known for their beautiful scenery like Iceland made it more enjoyable to live there. People also mine for copper in Chile which allows them to get money.

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Prediction and Building Design: Earthquake

Seisometers are used to moniter shockwaves within an area. Tiltmeters record the movement of the ground with would tell scientists if a fault would emerge. In Japan, there are buildings with reinforced latticework foundations placed deep in bedrock which stop the building for falling over and crushing people. They also have automatic shutters prevent glass from falling and hitting pedestrians below. Some buildings even have rolling weights on top which counteract shock waves, this also stops the building from falling down. If Izmit (the city most affected by the 1999 Turkey earthquake) then maybe 18,000 people wouldn't have died from falling buildings.

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How are volcaneos formed at Divergent plate bounda

At this place boundary, it doesn't matter what type of plates are involved as the result would be the same. Two plates move apart or in opposite directions due to convection currents in the mantle. Minor earthquakes often occur here. As the plates move apart a gap is left where magma can go up and fill. The sea floor speads and a new crust is formed and where volcaneos emerge above the sea, islands are formed. An island that has been created at this type of plate boundary is Iceland.

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