Chapter 1 – The earth system
Earth science: interactions among the four parts of the earth system: atmosphere (air, water), hydrosphere aka cryosphere
(water, ice), biosphere (plants, animals) and geosphere (land, rocks). The exosphere is sometimes considered the 5
system and consists of the sun and features from space.
A system is defined as inter-related elements comprising a unified whole. It consists of elements which are connected
together in order to facilitate the flow of information, matter or energy.
Components of the earth system:
1. Lithosphere: the solid earth; the upper part of the solid earth which interacts with the other components of the earth
system. It includes the physical layers. The crust of the earth interacts with everything else.
2. Atmosphere: a mixture of gases that consists of 78% nitrogen and 21% oxygen
3. Hydrosphere: total of earth’s liquid and solid water. ‘Sub-sphere’ = cryosphere which means frozen water
4. Biosphere: living and dead organic components. It is where living organisms can live or is suitable for living. It includes
vegetation on land and ocean, animals, plants, forests, ponds.
How is ecosphere different from the biosphere? – they are NOT the same. Ecosphere is the interaction between the
biosphere and with the other 3 (atmosphere, lithosphere and hydrosphere)
Technosphere is the sum of industrial, technological and agricultural components of human activity. Eg: manufacturing,
agriculture, transportation and energy production. It affects the natural system of the earth (ecosphere).
Sources of energy
1. External energy from solar radiation: drives the hydrologic cycle and the cir