• formed through lava flows
    • formed due to ejection of volcanic materials/volcanic ejecta
  • This is the state/condition of the atmosphere of a given place at a given time or over a short period of time

    • Faulting is the cracking or fracturing of the rocks of the earth's crust due to earth movement while folding is the bending of the rocks of the earth's crust due to earth movement
    • simple symmetric fold
    • assymetric fold
    • overfold
    • isoclinal fold
    • Recumbent fold
    • Nape or overthrust fold
    • Anticlinorium and synclinorium complex
  • (i) tectonic plates move toward each other

    • fold mountains
    • ocean trench

    ii) tectonic plates move away from each other

    • mid ocean ridges
    • faults
    • Changes in the position of the midday sun at different times of the year
    • Variation in the length of day and night at different times of the year.
    • Causes seasons
    • Causes lunar eclipse
    • painted white to reflect heat and light
    • is made of wood because wood is a poor conductor of heat
    • it has louvres to allow free circulation of heat
    • It has metallic legs/stand to prevent termites from destroying the wood
    • It is raised about 1.2 metres above the ground to prevent terrestrial radiation
  • (i) Canada - Praires

    (ii) Russia - Steppes

    • The area has scanty vegetation because of low rainfall
    • The high temperatures/ high rate of evaporation leave the ground dry leading to scanty vegetation
    • The long periods of drought causes seeds to remain dormant state only to germinate during short rains
  • Aridity refers to the state of land being deficient in moisture leading to scanty vegetation or lack of vegetation completely while desertification is the slow and steady encroachment of large areas of barren land covered with sand onto formerly productive agricultural land

    • Deforestation leads to severe soil erosion / interferes with hydrological cycle and arid conditions set in
    • Setting up of irrigation schemes and reclamation of swampland has led to the lowering of the water table level causing arid conditions to set in
    • Poor irrigation practices can lead to soil salinisation which would not eventually support plant life
    • Poor agricultural practices such as over cultivation, monoculture , shifting cultivation, ploughing up and down  the slope all lead to soil degeneration
  • The Contraction Theory

    After the formation, the earth's surface rocks cooled faster than those of the interior. As the interior continued to cool the surface rocks wrinkled to fit on the contracting interior leading to fold mountains

    The Convection Theory

    Convectional currents within the molten rock in the mantle move in circular motion towards the crust. These currents exert a frictional drag with the sima rocks causing crustal rocks to move horizontally resulting into the formation of fold mountains

    Plate Tectonics Theory

    When an oceanic plate meets a continental plate, the dense oceanic plate sinks beneath the higher continental one. The lighter continental plate due to compression crumbles to form fold mountains

    • Environment is the external conditions that surround an organism
    • Conditions that influence the behaviour and development of an organism
    • Climatology
    • Biogeography
    • Geomorphology
    • Hydrology
    • Pedology
    • They are made up of frozen gases/dust/small rocky particles
    • They have a head and tail
    • They move along oval-shaped orbit
    • They cross orbits followed by planets