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The reasons that people live in tectonically active areas and how this might relate to the level of economic development It is predicted that by 2050, 600 million people will be living in the tectonically active areas of the world. There are many reasons for settling within a tectonically active areas many people do not want to move due to factors such as: No where else to go, a lack of alternatives Through choice, fertile land and tourism will attract residents to stay Inertia; always lived there. Ignorance of risk, underestimating the level of risk Some people are unable to move due to a lack of financial resources or close family links or tradition. Well paid jobs and a pleasant climate outweigh concerns about tectonic risk.
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CASE STUDY: Mt Merapi in Java They have lived there all their lives and see no reason to move They are optimistic about taking their chances, and believe that sacrifices by shamans will appease the volcano and keep them safe If they moved to another part of Java they would still be near an active volcano as there are over 30 on the island The island is very densely populated The people who live on the slopes are farmers who benefit from the very fertile soils produced by the weathered volcanic ash (See above) - this means that any area they are moved to is unlikely to have soil which is as productive People are reluctant to leave friends and family in the area: "we were born here, and we'll die here..." On the slopes of Mt. Merapi in Java, Indonesia live over 30 000 people. They live there for a number of reasons: People are prepared to take a gamble with a volcano when there is food to be grown. In Indonesia, the fertile soils of Mt. Merapi allow up to 3 crops a year to be grown and harvested.
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The benefits of living within a tectonically active area: Volcanoes have some positive effects: They provide minerals and natural resources, such as diamonds, copper and cold. Ancient sea floor volcanoes contributed to huge amounts of metal such as lead, zinc and copper. Volcanoes provide nutrients to the surrounding soils, volcanic ash often contains minerals that are beneficial to plants Geothermal Energy water running through the earths crust is heated by high temperatures rock near the plate margins bringing geothermal energy towards the surface when it emerges from hot springs. Tourism, modern western cultures see volcanoes as beautiful aswell as threatening. Volcanoes generate large interest from visitors which can bring employment to poor remote areas.
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The range of Hazards associated with different types of tectonic activity Definition of natural hazard: A natural hazard is a threat of a naturally occurring event that will have a negative effect on people or the environment List of hazards and disasters: Earthquakes Land slides Tsunami Volcano Lahars Liquefaction Primary Hazards such as volcanoes and earthquakes are hazards that cause immediate and direct impacts. Secondary impacts such as landslides, tsunamis and lahars are all tectonic events that usually occur following a primary hazard. -Earthquakes often cause landslides, liquefaction and Tsunamis as a result of their vibrations and tremors. -Volcanic Activity is often associated with mudflows, landslides and lahars due to deposits and fragments involved within volcanic eruptions. The movement of plates produces different types of plate margins: Destructive - When an oceanic plate is forced under (or subducts) a continental plate Constructive - When two plates move away from each other Conservative - When two continental plates move towards each other
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Earthquakes: Definition: a sudden release of energy in the Earth’s crust, leading to ground shaking at the surface as energy spreads out from the origin (can happen between all plate margins) Volcano: Definition: An opening in the earth's crust through which molten lava, ash, and gases are ejected. They are generally found where tectonic plates are diverging or converging Effects they have on people: Primary casualties – people killed or injured in the event Secondary casualties – people who survive the initial incident but are either injured or killed due to insufficient resources and lack of medical care. No. of casualties tends to be higher in LEDCs Tertiary casualties – People who suffer from pre-existing medical conditions aggravated by the hazard e.g. disease or trauma Economic Impacts Direct costs are immediate costs of repairing damage caused by the event its self Indirect costs include loss of earnings caused by disruption towards working life. Within developed countries major tectonic events tend to cause large economic costs due to investments within buildings and infrastructure In MEDCs they will have higher economic costs because of large investments in buildings and infrastructure. LEDCs tend to have a higher loss of life. Primary Hazards:
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TECTONIC HAZARD HUMAN IMPACTS THE SPECIFIC IMPACTS OF A RANGE OF TECTONIC HAZARDS AT A RANGE OF SCALES AND AT LOCATIONS IN COUNTRIES AT DIFFERENT STAGES OF DEVELOPMENT a tectonic hazard is caused by convectional currents in the earths lithosphere. Tectonic activity is responsible for geo-physical hazards such as earthquakes, volcanic eruptions and tsunamis.
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Factors of Vulnerability Population growth and change Land pressure -> for example the occurrence of deforestation to provide farmland Urbanisation Economic growth Globalisation
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Red = earthquake distributionGreen = volcanoes
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Comparison of Earthquakes KASHMIR EARTHQUAKE, 2005 No resources Instability Criticisms Infrastructure Aid SICHUAN EARTHQUAKE, 2008 Building s collapsing Transport Water reserves damaged Agriculture Economic costs
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determination from other factors Population density Presence or absence of monitoring and alert systems Infrastructure Community preparedness Timing of the eruption
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Volcano Event MOUNT PINATUBO, 1991 Buildings collapsed Crops destroyed Agricultural land ruined
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Tsunamis No. Of Tsunamis Pacific Ocean828 Indian Ocean65 Atlantic Ocean61
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Comparison of Tsunamis THE ASIAN TSUNAMI, 2004 Infrastructure destroyed Economic loss Agriculture Destruction Migration OKUSHIRI TSUANMI, 1993 Properties destroyed Loss Overall damage
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Trends in Frequency and Impact over time Short Term Impacts of volcanic activity: Infrastructure Damage Loss of life Many native animals will leave but may soon return back to habitats usually within a year Food chains will be altered and left unbalanced Long Term impacts of volcanic activity Disease and illness Economic costs Decline in the countries population due to migration or death. Lots of people left homeless Environmental issues such as Lahars will arise these are known as mud flows each time it rains the pyroclastic material will mix with water and cause flooding and burying of houses aswell as towns. The impacts of earthquakes depend on the severity of the magnitude of the earthquakes, the distance from the epicentre and the local geological conditions. Hotspots: Are volcanic regions thought to be fed by the underlying mantle, these may be on, near or quite a distance from tectonic plate boundaries.
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Trends in Frequency and Impact over time Short Term Impacts of Earthquakes: Essential services may be destroyed Loss of life and damage to homes Transport and communication links disrupted Water pipes may burst and contamination of water supply may occur Fires spread due to gas pipeline explosions Tsunamis may cause flooding in coastal areas. Long Term impacts of Earthquakes: Income is lost Psychological affects Disease may spread The costs of rebuilding a settlement is high Investment within the area is based on repairing just the earthquake damage
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Earthquakes: there has been over 65 destructive events in the last 400 years mostly between the pacific and Eurasian plates. CASE STUDY: 1990 Earthquake Luzon, Philippines- 7.8magnitude created 125km long ground rupture as a result of strike slip movements along the Philippine fault line. An estimated 1,621 people were killed due to the earthquake mostly within central Luzon and cordillera region. There are 200 volcanoes within the Philippines 17 of which are active. The Luzon Island is densely populated CASE STUDY: Mt Pinatubo also located on the Luzon Island, second largest eruption of the twentieth century 55miles northwest of the capital city of Manlia up to 800 people killed and 100’000 homeless. With 9hours of eruptions 15million tonnes of sulphur dioxide were discharged into the atmosphere resulting in a decrease in worldwide temperature for the following years. Its part of a chain of composite volcanoes.
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Resources http://tallisa2units.weebly.com/1/post/20 09/8/first-post.html http://tallisa2units.weebly.com/1/post/20 09/8/first-post.html http://www.slideshare.net/jimster11/sichu an-earthquake-2754218 http://www.slideshare.net/jimster11/sichu an-earthquake-2754218 http://graphics.eiu.com/files/ad_pdfs/tsu nami_special.pdf http://graphics.eiu.com/files/ad_pdfs/tsu nami_special.pdf http://nctr.pmel.noaa.gov/okushiri_devas tation.html http://nctr.pmel.noaa.gov/okushiri_devas tation.html
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