AS Physical Revision

1 hour 15 minutes (40% AS)

The AS exam will test 4 key areas: hydrological systems; ecosystems; atmospheric systems; the lithosphere. The paper will be marked out of 100 (25 marks per topic). You need to be familiar with the detail of each topic and should concentrate on learning definitions, case studies and understanding processes. Make yourself a glossary, fact file and be familiar with the command words telling you what to do.

Hydrological Systems

• Hydrology: the global water cycle: inputs, processes and outputs. (Hart p.2-3)

• The local hydrological cycle. (Hart p.7)

o Inputs: precipitation & transfers. (Hart p.8-10)

o Outputs: evaporation; transpiration; evapotranspiration; runoff. (Hart p.10-12)

o Stores: atmosphere; vegetation/interception; surface; soil; groundwater; channel. (Hart p.12-15)

o Flows & transfers: throughfall; stemflow; infiltration; percolation; capillary action; run-off; throughflow; interflow; baseflow. (Hart p.16-19)

• Storm hydrograph. (Hart p.22-24)

• Annual hydrograph. (Hart p.26)

• Human impacts on the hydrological cycle. (Hart p.28)

• Flood protection methods, pros & cons. (Hart p.29-31)

• River Severn basin: CASE STUDY.

Ecosystems

• Energy flows. (Hart p.36-37)

• Nutrient stores and flows. (Hart p.37-40)

• Nutrient cycling between stores: Fig. 2.5. (Hart p.38)

• Soil profiles and influences of climate, vegetation, parent material, relief, rate of weathering, time (succession), human activity. (Hart p.43-51)

• Gley soils & podsols; the catena sequence. (Hart p.46-48)

• Broad-leaved deciduous forest ecosystem: structure, nutrient cycling & human activity; CASE STUDY (Hart p.41-43)

• Xerosere: dry conditions plant succession: the psammosere. CASE STUDIES - Braunton Burrows & Oxwich in Gower (Hart p.52-54)

• Human impact on sand dunes. (Hart p.54-55)

• Climax vegetation.

Atmospheric systems

• Earth-atmosphere systems. (Hart p.58-59)

• Processes: radiation; convection; conduction. (Hart p.60-62)

• Radiation (SW & LW) exchange: Fig. 3.7. (Hart p.62)

• Earth-atmosphere energy budget: Fig. 3.8. (Hart p.63)

• Absorbtion, scattering, reflection (albedo); latent heat. (Hart p.64)

• Energy budget variation with latitude. (Hart p.65)

• Energy transfers: ocean currents; general atmosphere circulation; weather systems (depressions & anticyclones). (Hart p.66-67)

• Depressions: features & weather conditions. (Hart p.68-70)

• Anticyclones: summer & winter. (Hart p.70)

• Air masses. (Hart p.71)

• Air stability.

• Local energy budget. (Hart p.70-74)

• Daytime budget. (Hart p.74-76)

• Nightime budget. (Hart p.76-77)

• Influence of ground surface temperatures on air temperatures. (Hart p.77-78)

• Snow, sleet, glazed frost and hail.

• Dew, hoar frost, mist and fog.

• Temperature inversions.

Lithosphere

Tectonic processes:

• Earth structure. (Hart p.85)

• Causes of plate movement. (Hart p.86-87)

• Types of plate boundary: constructive. (Hart p.88-89)

• Sea floor spreading; mid ocean ridges; rift valleys.

• Types of plate boundary: destructuve. (Hart p.89-90)

• Subduction zones; earthquakes; island arcs; fold mountains; collision zones.

Weathering:

• Physical: freeze-thaw; heating & cooling; solution; oxidation; wetting/drying; organic action; pressure release (Hart p.95-97)

• Chemical: hydrolysis; hydration; carbonation; solution; oxidation; organic action/chelation. (Hart p.97-100)

• Factors controlling weathering: climate; rock type; rock structure; vegetation; relief. (Hart p.98-100)

• Human activities affecting weathering.

• Limestone (pavement) and chalk (scarp & dip). (Hart p.100-104)

• Granite including tors. (Hart p.104-105)

Slope systems: