5.1a

• flows/transfers?

  movement of matter or energy between stores
• input?

  matter or energy is added to the system
• output?

  matter or energy leaves a system
• store?

  where matter or energy builds up
• closed system?

  energy or matter is contained in the system
• dynamic equilibrium?

  the inputs and outputs are balanced but can fluctuate
• positive feedback?

  moving away from the norm
• negative feedback?

  returning to the norm
• what type of system is the global hydrological cycle?

  Closed system --> no external inputs or output of water

  water is continuously cycled between different stores
• what is the global hydrological system driven by?

  solar energy --> heat moves water from the surface of the Earth to the atmosphere (evaporation)

  gravitational potential energy --> the force that causes water to flow downhill, both on the surface and through soil, and precipitation
• why is the global hydrological cycle a closed system?

  • outputs are restricted by the atmosphere which acts as a boundary
  • inputs aren't likely to occur unless asteroids were to contribute to the Earth's water content