Flashcards
Volcanoes and earthquakes: MEDC and LEDC case studies
Flashcards do conjunto (13)
- 1Mauna Loa (shield) and Mount Pinatubo (composite) – contrasting volcanoes • Mauna Loa is in Hawaii • It is one of the most active volcanoes on the planet • It is the widest volcano on the planet and forms half the main Hawaiian ‘Big Island’ • Shaped like a shield with gently sloped sides • Lava is runny and the volcano is rarely violent • The most common eruptions are ‘fountains in a long line at the summit of the volcano• Mount Pinatubo is a level 6 on the ‘explosivity’ index
• Erupted in 1991 for the first time in 500 years
• The magma is sticky andesitic lava which frequently blocks the vent
• Pressure builds up so explosions are very violent
• There is also clouds of ash, gas and pyroclastic flows when the volcano erupts
• The shape of the volcano is steep sided like a cone - 2Haiti and New Zealand – the effects of an earthquake in an MEDC & LEDC • Haiti is in the Caribbean, on the island of Hispaniola • There was an earthquake in 2010 that measured 7.0 on the Richter scale with the epicentre near the capital Port-au-Prince • 3 million were affected with 230,000 dead, 300,000 injured, 1,000,000 homeless and 30,000 commercial buildings collapsed • Poor infrastructure meant that more building collapsed leaving more people dead injured and homeless • There was looting as a result of all the collapsed buildings and the economy was ruined due to the damage • Overcrowding + poor people = Large number of deaths + small costs• New Zealand is near Australia and its capital is Christchurch
• In 2010 there was a earthquake that measured 7.1 on the Richter scale with the epicentre 40 kilometres west of Christchurch
• Only two people were seriously injured with just one dead
• This was because New Zealand has strict building codes and whilst there was damage, buildings did not collapse
• The economic costs were larger than Haiti because New Zealand is an MEDC and Haiti is an LEDC
• The earthquake cost the government $4bn
• Less population density + rich people = Small number of deaths + large costs - 3Sakurajima Volcano, Japan and Mount Nyriagongo in the Congo – the effects of a volcano in MEDCs & LEDCs • In the Congo, people live near active volcanoes as the ground is very fertile for growing food • People are very poor, can’t afford well built homes, have no insurance, the Government has no money to provide aid and there is poor communication • There were volcanic bombs, ash clouds, a pyroclastic flow as well as lava that poured out at 40mph • 100 died and 120,000 were left homeless as 20% of homes were destroyed • This meant that many people became refugees and a volcano monitoring station was set up• The Sakurajima Volcano in Japan is closely monitored for eruptions as Japan is an MEDC and can afford to do this
• Tilt meters detect when the volcano is filling with lava, hot springs are closely monitored, seismometers inside tunnels in the volcano measure earthquakes (as number of earthquakes increase as the magma rises) and aircrafts are used to measure the amount of gas a volcano gives off
• There are also concrete shelters that protect against volcanic bombs and ash, concrete channels divert dangerous mudflows, evacuation routes are clearly signposted; people have regular evacuation drills
• If this volcano did erupt it would be likely that there would be a low death toll in comparison to Mount Nyriagongo as there are methods put in place to predict eruptions and to protect people from them - 4Tsunami in Japan – effects • The Tsunami happened in 2011 and even though Japan is an MEDC, there were devastating consequences • 12,431 people died with 15,153 left missing • Over 163,000 people were evacuated • The tsunami damaged the Fukushima power plant meaning that those who lived within a 12-mile radius of the nuclear plant were evacuated (over 70,000 people0 • 165,000 households were left without electricity, 170,000 households left without water and 46,000 buildings were destroyed, washed away or burnt down • The estimated damage cost the damage 16-25 trillion yen making it the world’s costliest natural disasterMontserrat – safely predicting and evacuating a volcano
• The island of Montserrat was home to less than 10500 people in the early 1990s
• Many small earthquakes were detected beneath Montserrat and although they were too small to be felt, seismologists realized they were caused by magma forcing its way up through the crust and scientists arrived on Montserrat to monitor activity
• The Soufriere Hills volcano began erupting on 18 July, 1995 and erupted for months meaning that ash covered the south of the island as the eruptions were explosive but fairly small
• In August 1995 scientists saw that the activity was intensifying and evacuated the south. Minor evacuation continued up until mid-1996 when pyroclastic flows became larger and more frequent and once again the south was evacuated to the north
• On 25 June, 1997, a huge pyroclastic flow rushed down the volcano at 100mph and 19 people were killed and after many other major eruptions, the south of the island was effectively lost - 5Izmit, Turkey and Kashmir, Pakistan - evaluating the responses and long term planning in earthquakes • In Izmit, an earthquake struck on October 19th, 1999 • 17,000 died and 40,000 were injured • The government was slow to respond as it was unprepared and there was no long term planning, this made it into a major disaster • The Red Crescent, US and Europe were all involved in the relief effort• Kashmir is a disputed territory between India and Pakistan
• A 7.6 earthquake happened there in 2005 with many casualties and 75,000 dead
• There was no long term planning for the earthquake and both India and Pakistan are poor countries meaning that there is no building regulations causing a higher death toll
• India, Pakistan, UN, US and UK were all involved in the relief effort however Pakistan was criticised for wasting money it could have given as aid on training and services - 6Natural climate change: Little Ice age (historical climate change) the effects on people and ecosystems • Lasted from around 1300 to 1870, was probably caused by sunspot activity and meant that average temperatures were 1 degree lower than normal • Winters became much colder and longer and this reduced the growing season by several weeks. This would have affected the amounts of crops produced and meant that there was widespread famine • Remote areas like Greenland was abandoned by settlers as survival became impossible • The price of grain increased everywhere leading to social unrest and revolt • Some ecosystems suffered as a result of the lower temperatures and growing glaciers however some thrived in the colder conditionsMegafauna (geological climate change) – the effects on the ecosystem
• 10,000-15,000 years ago the ice age ended due to a rise in temperatures by as much as 5 degrees in 1,000 years
• During this natural period of global warming, large animals called megafauna (130 different species) became extinct
• The reason they became extinct was that these species at the top of different food-chains were not able to adapt to other ecosystems and this is important as their food in their own eco-systems was unable to survive the temperature change - 7UK – the economic and environmental effects of climate change (developed country) • Environmental effects include: • New bird and animal species will migrate to the UK while others will disappear • There will be a change to fish species available for fishing e.g. cod will move north out of the North Sea • Increased numbers of storms will cause more coastal erosion• Economic effects include:
• It will be expensive to protect low-lying areas such as London from rising sea levels
• It will be even more expensive to run the NHS as a result of extra problems caused by frequent heat waves
• More floods would mean the government would have to spend a lot on flood protection
• Domestic tourism could increase but the Scottish skiing industry could disappear
• Farmers will have to change crops and irrigation costs could rise - 8Bangladesh – the economic and environmental effects of climate change (developing country) • Environmental effects include: • More frequent cyclones in the Bay of Bengal • Rising sea levels would erode the country’s coastal mangrove swamps • Northwest Bangladesh could have more droughts• Economic effects include:
• Costs of dealing with more frequent floods as a result of an increase in rainfall and Himalayan glaciers melting
• 10% of land could be lost to rising sea levels, this would make people homeless and unable to grow crops
• Severe water shortages if the monsoon rains fail - 9The Adis people in northern India – how mountain rainforests are used sustainably • The Adis people practice a ‘slash and burn’ method to help them do subsistence farming • There are five steps to slash and burn: an area of forest is burnt after clearing, ash is then spread over the cleared soil, crops are planted and grow well in nutrient rich soil, after 4-5 years the nutrients in the soil become exhausted and then the farmers move into a new area of forest whilst the previous area recovers • There are a few threats to this sustainable method of farming: some tribes have had land taken for timber use, tribes have bought modern materials, schools and roads have been built leading to a huge threat to traditional land. As soon as the tribes start buying modern materials, they have to sell crops, hunt more and sell timber leading to more pressure being put on the landKilum, Cameroon (Africa) – local scale management of biomes - Core conservation and buffer zone.
• The forest covers a relatively small area of 20000 hectares and is important for the 200,000 locals who live less than a day’s walk away
• In 1994, a 20 year management plan was agreed for Kilum to become a community forest and it recognised the conflict between the locals who wanted the forest for goods and services, and the government who wanted it for conservation and biological diversity
• The forest was split into different zones. The core reserve protects the biodiversity and allows the forest to grow naturally. It is protected by signs fences and patrols. In this zone, it is illegal to farm, hunt or create fires. The Fulani people have been living in the forest for generations so they are allowed to farm sustainably
• Around the core there are buffer zones that can be used in small amounts. In these buffer zones, diversification is required to encourage farmers to produce things other than crops e.g. beehives. The aim of this is for people to be able to make money without having to clear areas of the forest to farm. Areas for eco-tourism have also been set up within the buffer zone to give local people another way to make money - 10The Tropical Rainforest: Ecosystem Goods and Services • Goods include: • Trade (timber and other natural resources) • Food for both animals and people • Water for both animals and people• Services include:
• The nutrient cycle – dense vegetation means twigs and leaves fall to ground and become litter, this litter decomposes thanks to termites, fungi and bacteria, this decomposed litter means that its nutrients enter the soil causing fertile soil
• Green lungs – essentially the oxygen cycle and means that many ecosystems provide a service of recycling air
• Water control – forests and plants intercept rainwater and store it in their leaves, branches and roots, some water is used for growth and some evaporates, when plants and trees are cut down rainfall often reduces as the land is no longer protected from heavy rain, so fertile soil is washed away and the land is ruined. Essentially, plants and trees provide the service of making the water cycle work and they provide a protection layer to the soil
• Habitat and gene pool- the more diverse the ecosystem, the more diverse the range of animals, this increases genetic diversity which is key to the survival of life on earth - 11Amazon rainforest – how is the rainforest been degraded by direct destruction – deforestation, mining, conversion to farmland • Logging – trees are being cut down as the prices of certain trees are high due to demand from consumers in developed countries, random logging means that for every tree cut down, thirty more can be destroyed in the process and as a result of this 5m hectares are destroyed annually • Mining – There is iron ore, gold, platinum, copper, lead and aluminum in the Amazon. To mine these minerals, large areas have to be cleared. The largest mine in Brazil is the Carajas project which is about the size of the UK and France combined. Rivers are also polluted with metals during the mining process• Cattle ranching – Large areas are cleared to grow grass for cattle. Since the 1950s, around 60% of the Amazon’s lowland forest has been turned into pasture for cattle. The soil in the rainforest is infertile as the heavy rains wash the nutrients away. This means that the grass grown for the cattle soon declines and nutrients are lost. As a result, larger areas of the rainforest are cleared to grow even more grass
• Hydro-electric power (HEP) – About 75% of Brazil’s electricity comes from HEP as there is a large amount of daily rainfall. Dams and reservoirs have to be built to create HEP and they mean that large areas of tropical rainforests have to be flooded causing large scale destruction - 12Antarctica – indirect degrading of the biome by climate change – declining krill & fish • Global warming is leading to warmer air and sea surface temperatures in Antarctic. • This leads to a reduction in Sea ice. Krill feed on the algae found under the surface of the sea ice. • This in turn leads to less Emperor penguins, which feed on the krill. The numbers of Emperor Penguins fell by 50% in Adelie Land Antarctica when the temperatures rose by 30 degrees C. • In fact it disturbs the whole Antarctic food chain as Killer Whales feed on Emperor Penguins.UK & birds – indirect degrading of the biome by climate change – declining birds
• Global warming is likely to cause an increase in severe heat waves.
• Both these heat waves and warmer winters will lead to trees having less water than they need.
• The stress placed on trees will lead them to die and grass to dominate instead.
• Scientists believe that birds will face difficulties to these changing conditions. Half of the UK’s migratory birds have already experienced a severe decline e.g. Yellow wagtail – declined by 70% and Turtle Dove– declined by 82% - 13CITES – Global scale approaches to biosphere managements • CITES stands for the Convention on International Trade in Endangered Species and is an international agreement between governments. Its aim is to ensure that international trade in specimens of wild animals and plants does not threaten their survival • It does this by tightening and enforcing legislation through: • Helping countries comply with CITES regulations • Helping to create new national, state, and local laws • Running training workshops for customs officers, border police, nature conservation officials, scientists, and traders to give them the appropriate skills and tools to comply with and enforce wildlife trade laws • Assisting with enforcement efforts. For example, giving information to the police that led to a raid in 2003 on an illegal Thai wildlife slaughterhouse that was supplying restaurants with tiger, orang-utan, and bear products • Helping with anti-poaching efforts and encouraging cross-border cooperation• CITES also works through public education by:
• Raising public awareness of issues that include:
• Discouraging purchases of certain wildlife goods e.g. ivory
• Encouraging production and purchases of sustainable wildlife goods
• Working with local communities to overcome poverty and help them use their local wildlife in a sustainable way
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- FlashCards sobre Sem título, criado por davidjfiler em 09-04-2014.
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