earths life support systems

Question 1

whys water important

Answer 1

• supports all forms if life
• carries substances in and out of all living cells
• maintains the correct living requirements for all fauna and humans
• helps to regulate the earths surface temp
• helps to maintain atmospheric temps
• Is used in a wide range of economic activities

Question 2

whats carbon important

Answer 2

• occurs in mineral form, in living form and as a gas
• forms the buildings block for much of the natural world
• provides the basis of the most of the worlds energy supply
• provides a major raw material for a wide range of manufactured products

Question 3

water stores key features

Answer 3

• of the worlds water 97% is saline sea water
• almsot 80% of total fresh water is locked up in ice and glaciers
• another 20% of fresh water is in the ground
• surface fresh water sources, such as rivers and lakes, constitute only about 1/150th of 1% total water

Question 4

the hydrosphere (water store)

Answer 4

• oceans hold the vast majority of all water on earth
• oceans supply about 90% of the evaporated water that goes into the water cycle

Question 5

the atmosphere (water store)

Answer 5

• contains a very small store of water
• is the main vector that moves water around the globe

Question 6

the cryosphere (water store)

Answer 6

• antartica holds almsot 90% of the global ice mass
• the Greenland ice cap contains 10% of total global ice mass
• ice caps and glaicers collectively cover about 10% of the earths surface

Question 7

the lithosphere (water store)

Answer 7

• surface fresh water represetns around 2.5% of all water on earth
• river hold onto about 0.006% of total fresh water reserves
• large quantities of water are also held deep underground aquifers
• water form aquifers van take thousands of Yeats to move back to the surface

Question 8

whats an aquifer

Answer 8

a body of porous rock or sediment saturated with groundwater. Groundwater enters an aquifer as precipitation seeps through the soil. It can move through the aquifer and resurface through springs and wells.

Question 9

whats an artesian basin

Answer 9

a low-lying region where groundwater is cramped under pressure from surrounding layers of rock. These basins are usually found where an aquifer is present in a syncline, by impenetrable layers above as well as below. Whenever a fissure breaks the surface, the underground water blow up

Question 10

examples of carbon stores

Answer 10

• volcanoes
• ocean loss
• ocean uptake
• plants
• burning fossil fuels
• plant respiration
• photosynthesis
• fossil fuels
• earths crust

Question 11

carbon stores

Answer 11

• most of the earths carbon is stored in the lithosphere (99%)
• much of this is in fossil fuel rocks and limestones
• carbon flows between each of these stores in a complex set of exchanges
• any change that shifts carbon out of one store puts more carbon in another store

Question 12

types of water inputs, outputs and flows

Answer 12

• evaporation
• evoptranspiration
• condensation and cloud formation
• precipitation
• snow melt

Question 13

whats evaporation

Answer 13

• heat is necessary for evaporation to occur
• this is why water easily evaporates ar the boiling point
• evaporation from the oceans is the primary mechanism supporting the surface to atmosphere transfer of water

Question 14

whats evapotranspiration

Answer 14

• this is the combined water loss to the atmosphere by evaporation form the ground surface and capillary fringe of the water table, and the transpiration of groundwater by plants whose roots tap the capillary fringe of the water table

Question 15

whats condensation and cloud formation

Answer 15

• condensation occurs when saturated air is cooled, usually by a rise in altitude to below the dew point
• condensation is responsible for the formation of clouds
• clouds may produce precipitation, a route by which water returns to the earths surface

Question 16

whats precipitation

Answer 16

• occurs when tiny water droplets condense on microscopic dust, salt or smoke particles, which act as condensation nuclei
• droplets may grow due to additional condensation of water vapour or where droplets collide

Question 17

whats snow melt

Answer 17

• runoff from snowmelt varies in importance both geographically and over time
• in areas with colder climates, much springtime flow in rivers is attributable to melting snow and ice

Question 18

whats sequestration

Answer 18

the long-term storage of carbon in plants, soils, geologic formations, and the ocean.

Question 19

name the carbon inputs, outputs and flows

Answer 19

• weathering
• photosynthesis, respiration, decomposition and combustion

Question 20

whats weathering

Answer 20

• atmospheric co2 combines with water vapour to form a weak carbonic acid that falls as precipitation
• this acid dissolves rocks and reads calcium maghenisum, potassium and sodium ions
• plants through their growth also break up surface granites

Question 21

whats photosynthesis, respiration, decomposition and combustion

Answer 21

• plants and phytoplankton are key components of the carbon cycle
• during photosyentheis, plants absorb c02 and sunlight to create glucose and other sugars for building plant structures
• phytoplankton also take co2 from the atmosphere by absorbing it into their cells
• using energy from the sun, both plants and phytoplankton combine co2 and water to form carbohydrate and oxygen

Question 22

carbon can be returned to the atmosphere by

Answer 22

• respiration, plants break down the carbohydrate to get the energy they need to grow: animals and people eat the plants and break down the sugar to get energy
• decomposition, plants and plankton die, decay and are eaten by bacteria at the end of the growing season
• combustion, natural fire consumes plants

Question 23

drainage basins

Answer 23

• the drainage basin hydrological cycle allows the water cycle to be examined at a local scale
• inputs include energy from the sun
• outputs include evoptranpiration, water percolating into deep groundwater stores and runoff into the sea
• stores take place on vegetation, on the ground, in the soil and in underlaying bedrock

Question 24

stores and flows in a drainage basin

Answer 24

• groundwater flow, the movement of groundwater this is the slowest transfer of water within the drainage basin and provides water for a river during drought
• groundwater store, water that collect underground in pore spaces in the rock
• infiltration, the movement of water from the surface downwards into the soil
• interception, the process by which precipitation is prevented from reaching the soils by the leaves and branches of trees as well as by the plants

Question 25

what are the carbon natural variations

Answer 25

wildfires and volcanic acitivty

Question 26

wildfires

Answer 26

• cam be caused by lighting strikes
• most are started by humans but go out of control
• forest fires can release more carbon into the atmosphere than forests can capture
• everyyear wildfires burn 4millionkm2 of the earths land area, and release tonnes of co2 into the atmosphere

Question 27

volcanic activity

Answer 27

• carbon is emitted to the atmosphere through volcanoes about 0.1Pg of co2 per year
• during subduction heated rocks recombines into silicate minerals releasing co2
• when volcanoes erupt they vent the gas to them atmosphere and cover the land with fresh silicate rocks

Question 28

human impacts on carbon

Answer 28

• people have influenced the carbon cycle where fossil fuels have been mined and subsequently burnt
• fossil fuels range from volatile materials with low carbon to hydrogen ratios such as methane to liquid petroleum and to non volatile materials composed of almost pure carbon, such as athraitce