Water and Carbon 2 The Water Cycle

Global Distribution and Size of Major Stores of Water:

• Water distribution: 
• Water moves between different spheres:
  • lithosphere: water in the rocks and soil
    • Groundwater
  • hydrosphere: water on Earth’s surface
    • Rivers, lakes, seas, oceans
  • cryosphere: water held in ice form
    • glaciers, ice caps, ice sheets, sea ice, permafrost
    • Sea ice: 
      • When sea water freezes
      • Found in Artic Ocean
      • Grows and shrinks in summer and winter
      • Does not raise sea levels when it melts because it came from the sea
    • Ice shelves:
      • Platforms of ice that form where ice sheets and glaciers move out into the oceans
      • Found in Artic near Canada and Alaska and in Antartica and Greenland
    • Ice Sheets: 
      • A mass of glacial land use extending more than 50,000km²
      • Form in areas where snow that falls in the winter does not melt entirely over the summer
      • If the Greenland ice sheet melted then the sea level would rise 6m
      • If the Antarctic ice sheet melted then the sea level would rise 60m
    • Ice caps:
      • Thick layers of ice on land that are smaller than 50,000km²
      • Usually found in mountainous regions e.g. the Furtwangler Glacier on Kilimanjaro
    • Alpine glaciers:
      • Thick masses of ice found in deep valleys or in uplands hollows
      • Most glaciers are fed by ice from ice caps
      • Glaciers provide a reservoir of water e.g. 15,000 Himalayan glaciers provide water for The Three Rivers (Ganges, Brahmaputra and Indus) which in-turn provides a lifeline for millions of people in South Asia
    • Permafrost: 
      • Ground that has remained at or below 0℃ for at least two consecutive years
      • As permafrost melts, it releases carbon dioxide and methane into the atmosphere
      • Permafrost covers most of Russia
  • atmosphere: water held in the atmosphere as water vapour
    • Clouds
      • Water vapour absorbs, reflects and scatters incoming solar radiation keeping the atmosphere at a temperature that can maintain life
      • Cold air cannot hold as much water vapour
  • biosphere:
    • Plants
    • Animals 

Terrestrial Water:

• Surface water:
  • Rivers
    • Act as a store and transfer of water
    • The Amazon River has the greatest discharge of water in the world 200,000㎥/s and drains an area of 7,000,000km²
  • lakes: 
    • Fresh water found in hollows on the land surface
    • Larger than 2 hectacres
  • wetlands:
    • Areas of marsh, fen, peatland, or water, whether natural or artificial, permanent or temporary, with water that is static or flowing where there is a dominance by vegetation
    • Areas where water covers the soil
    • Pantanal, South America, is the largest wetland system 
    • Arctic wetlands store large amounts of greenhouse gases
• Groundwater
  • Water that collects underground in the spore spaces of rocks
  • Groundwater eventually flows to the surface
  • The amount of groundwater is decreasing because of irrigation systems used in agriculture in dry areas
• Soil Water
  • Water that is held together with air in the unsaturated upper weathered layers of Earth
  • Soil moisture plays a role in weather patterns and the production of precipitation
• Biological Water:
  • Water stored in all the biomass
  • Deforestation causes a loss of…