oceans


HideShow resource information
View mindmap
  • Oceans
    • pattern of ocean currents can disperse pollution
      • Debris enters the oceans from rivers, beaches and vessels, deliberately or not. Some bio degrades but vast quantities don't - marine debris poses dangers e.g creatures being tangled in it. biggest issue is plastic- don't bio degrade but break into micro plastics which organisms ingest. passes through food chains into different trophic levels
      • Great Pacific garbage patch
        • 2 giant pools of plastic soup, slowly rotating due to gyres, 1 million pieces of plastic per square mile , creates landfill along the shorelines of many wilderness regions, Pacific Hawaiian islands, srctic circle islands e.g. muffin islands
        • plastics: created in the late 1800s, low cost so adds perceptions of 'throwaway' ,unnecessary packaging and growth of bottled water, 1/3 of of plastic is designed as throwaway- lifespan less than a year, plastic bags are made of petro chemicals so don't bio degrade- just gets smaller
    • climate change
      • ocean acidification
        • oceans are carbon sinks- absorbed 30% of carbon generated over the last 250 years. 25% increase in acidity in the past 200 years
        • impacts on ecosystem- marine organisms require calcium carbonate. increase in acidity reduces ability of marine organisms to build skeletons e.g zooplankton are less likely to reach maturity and breed. a collapse in numbers will affect the food chain at all trophic levels.
          • affects carbon cycle - when marine organisms die they fall to the seabed and store carbon for millions of years.
        • impacts on people
          • threatens catching of shellfish and fish. put food security at millions at risk. EDCs and LIDCs depend on fish for protein e.g Gambia- 50% of their dietary needs
      • warming oceans and coral ecosystems
        • Algae give coral its colour, they release nutrients via photosynthesis which polyps feed on- algae are protected by coral- warming oceans stress coral and algae- too much stress and the algae is expelled and coral bleaching occurs.
        • Great barrier reef
          • importance- Australian icon, 2 million visitors a year, 69,000 jobs supported, $6 million contributed to Australia economy, one of 7 natural wonders of the world, 600+ types of coral, 2000 species of fish
          • threats: rapid human induced climate change: increased severe weather events--> intense cyclones destroy reef. Rising sea temp--> risk of heat stress+ coral bleaching. Ocean acidification--> changes ocean chemistry. Rising sea level--> higher seas can impact many areas including erosion
          • extent of damage: 2/3 of coral in North have died in worst coral bleaching event. Cape York- 50% coral loss
    • climate change and sea levels
      • Thermal expansion of water-  as temp rises, density decreases and volume increases
      • melting of glaciers- as atmosphere warms ice melts and goes into the ocean
      • Kiribati Islands
        • located: central tropical pacific- 32 atolls, 1 raised coral,population of 112,850.poorest countries in the world, bulk of production is fish
        • low lying in the middle of the ocean
          • threats: thermal expansion of water, melting of glaciers, melting of Greenland and Antarctica ice sheets-CO2
            • Thermal expansion of water-  as temp rises, density decreases and volume increases
            • melting of glaciers- as atmosphere warms ice melts and goes into the ocean
        • Water levels increasing due to CO2 emitions
          • primary impacts: crops cant grow because of salt water, mass loss of land, storm surges,king- coastal erosion, loss of coconut trees, flooding of houses, loss of fresh water
            • Secondary impacts:production of coconuts and breadfruit will decrease, islands becoming narrower, Tarawa is suffering from over crowding, cyclones and hurricanes are occurring frequently,sewage contamination in coastal waters
        • no more food, housing being destroyed
          • short term adaptions: raise awareness, protect water sources, rebuilding sea walls, homes on stilts
            • long term adaptions: Buy land in Fiji, buy land in England- dense forest £8.77 million, land in India + Sri Lanka- agriculture and fishing projects, apply for jobs in neighbouring countries e.g. New Zealand
    • climate change is altering high latitude oceans
      • Arctic
        • Albedo effect- arctic has high albedo, solar radition is reflected into space due to ice cover
        • Climate change effects:
          • Future: when sea ice melts more solar radiation will be absorbed- warming ocean, encourages more melting- irreversible cycle
            • Albedo effect- arctic has high albedo, solar radition is reflected into space due to ice cover
          • military activity has been measuring ice thickness- 1960's- 4M thick now 1.25M thick
          • Social impacts: inuits loose hunting ground-loss of ice, low adaptive culture- at risk however reduction in sea ice means more transport and communication
          • Environmental impacts: Enhanced agriculture and forestry, increased access for marine shipping, however, water from sea ice increases sea level, herd animals change migration routes
          • Economic impacts: when ice melts it will expose land to exploitation of oil gas and fish, 80% of Inuits hunt caribous, fish, marine mammals and they are declining however, tourist ships able to visit northern Canada- 30% on Inuits income e.g. sculpture making
        • Geopolitical: USA and Russia confront each other over short distances, Canada and UK have interest sin the region , tension between competing powers has increased
          • ' melting in Alaska Arctic'-council meet up to address ongoing efforts on a range of topics- climate change, undiscovered resources under Arctic- raised stakes in unsettled border disputes- harden negotiation positions
    • globalisation and oceans
      • factors influencing global shipping routes
        • shape of coastline, winds, ocean currents, water depths and offshore reefs, sea ice
        • Panama Canal- built 1855- first ocean land bridge. Atlantic- Pacific transit- revolutionised sea trade, given importance to Panama- widening locks to 55m, takes 14 hours- saves 10 days
        • Suez canal-17 hours, saves 20 days, located in Egypt, allows transportation directly between Europe and Asia- alternatives would be navigating around Africa. 2007 more than 7,700 ships passed through- 7.5 % of ocean trade
      • containerisation- reduces costs at every stage from factory to customer. efficiently loaded and unloaded- dramatic change in the past 50 years. one ship can carry up to 18,000 containers- promotes globalisation.
      • Submarine cables- unseen connections:by 20th century a network of cables had been installed in Atlantic ocean, Internet could not function without the network of fibre-optic cables in the ocean
    • countries challenge each other over oceans
      • south China sea conflict zone
        • causes: dispute over territory, china has backed its claims with Island building, largely linked to mineral wealth of neighbouring areas, sea is a major shipping route and home to fishing grounds, china claims largest portion of territory
          • impacts: rising in military funding, tension between countries involved, countries becoming secretive, world leaders involved, threats from china to avoid harming the peace
        • 2016, Obama backed Vietnam- all territory should be respected- must abide by the rules
        • Sea is very important due to trade passing though it
        • China has claimed many islands, constructing facilities to service ships and aircraft on them
    • Oceans present hazardous obstacles to humans
      • Piracy
        • rise in transoceanic trade has been accompanied by a rise in modern piracy.
          • growth in piracy- poverty, dysfunctional gov. links to organised crime networks, profits from piracy launder. Fisherman in Somalia- link piracy with loss of their traditional fishing industries.
        • Petro piracy-Gulf of guinea tankers, drilling platforms and supply vessels have become targets
        • Management- international action, EU, NATO, USA and other countries patrol the vulnerable areas, surveillance has reduced attacks in Indian Ocean in recent years. 2010-445 attacks 1026-191 attacks
      • escape for refugees
        • Eritrea to Europe
          • push factors- low economy, famine, military dictatorship, forced to join military, conflict, civil unrest
          • pull factors: good economy, healthcare, freedom, can support family, jobs, safety
          • Problems- overcrowding- illness, no life jackets- cant swin, denied closure, expensive, face kidnapping, dont get asylum till in the country
    • Untitled

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all oceans resources »