oceans
- Created by: lizzie.cotton
- Created on: 31-05-18 16:17
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- 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
- ocean acidification
- 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
- threats: thermal expansion of water, melting of glaciers, melting of Greenland and Antarctica ice sheets-CO2
- 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
- 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
- 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
- short term adaptions: raise awareness, protect water sources, rebuilding sea walls, homes on stilts
- 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
- Future: when sea ice melts more solar radiation will be absorbed- warming ocean, encourages more melting- irreversible cycle
- 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
- Arctic
- 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
- factors influencing global shipping routes
- 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
- 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
- south China sea conflict zone
- 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
- rise in transoceanic trade has been accompanied by a rise in modern piracy.
- 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
- Eritrea to Europe
- Piracy
- Untitled
- pattern of ocean currents can disperse pollution
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