Social Science Geography Gr8 Term 1

• Earth's axis tilts at 23 ½ degrees away from perpendicular, affecting the length of day and night and causing the seasons
• Different parts of Earth tilt towards or away from the sun at certain times of the year due to the tilt of Earth's axis
• It takes 365 1/4 days for Earth to complete one revolution around the sun, resulting in the four seasons due to the tilt of Earth's axis
• The tilt of Earth's axis and its revolution around the sun give rise to the four seasons in different parts of the world
• Satellite images in agriculture are used to:

  • Detect plant diseases
  • Determine plants needing nitrogen-rich fertilizers
  • Identify drought-stressed plants in need of water
  • Assess crop yields and soil quality
• In the environment, satellite images are used to:

  • Measure air quality and pollution levels
  • Detect pollution sources in areas with poor air quality
  • Monitor declines in fish species in bodies of water
• Satellites are human-made objects put into space to orbit around Earth
• Satellite images are used to study weather patterns, tropical cyclones, land use patterns, soil erosion, and vegetation cover
• Seasonal temperature changes are influenced by the amount of sunlight received, with places near the equator being warmer
• Equinoxes occur on 21 March and 23 September, with equal day and night hours
• Solstices occur on 21 December and 21 June, marking the longest and shortest daylight hours in each hemisphere
• South Africa has a 15° and 30° longitude line, resulting in two different time zones
• Earth takes 365.25 days to complete one revolution around the sun, with leap years adding an extra day to February
• Time zones are adjusted by governments to fit their country's borders, with each country calculating time based on their time zone and the Greenwich Meridian
• China has one time zone despite its longitudinal expanse that should technically have four time zones
• The International Date Line follows the 180° line of longitude, dividing the world into the eastern and western hemispheres in the Pacific Ocean
• Travelling from east to west results in losing a day, while travelling from west to east gains a day
• The Earth's axis is an imaginary line passing between the north and south pole, around which the Earth rotates from west to east in 24 hours
• Latitude measures distance north and south of the equator, while longitude measures distance east or west of the Prime Meridian
• An atlas is a book containing different kinds of maps representing the Earth's surface, with world, regional, and local scale maps
• Maps


  Scaled versions of real areas, designed to fit on a piece of paper. Distances in the real world can be worked out using the scale on a map
• Earth's rotation

  The rotation of planet Earth around its own axis in an eastwards direction
• Earth's revolution

  Earth revolving around the Sun. It takes much longer than its rotation on its axis. One complete revolution takes 365 days, or one year. Gravity keeps the Earth in a roughly circular orbit around the Sun
• Latitude


  Imaginary lines stretching from east to west on the globe and measured in degrees
• Longitude

  Imaginary lines stretching from north to south on the globe and measured in degrees
• Earth is one of the eight planets in our solar system
• Scale


  The amount by which things are made bigger or smaller. Scale is used to reduce real objects to fit in a small space
• Word scale


  Tells us in words how much 1 centimetre (cm) on a map represents on the ground
• Line scale


  A line divided into equal sections, each section representing a certain distance on the ground
• Ratio scale


  Shows the ratio of one unit of measurement on the map to that same unit of measurement on the ground. For example, 1:8,000,000 means 1cm on the map represents 8,000,000 cm on the ground
• Large-scale map


  Shows a small area, such as a town or a farm. The larger the scale, the more detail a map can show
• Small-scale map


  Shows a large area, such as a province or a country. A world map has a very small scale
• Winter solstice is when the sun's rays fall directly on the Tropic of Cancer, occurring on 20 or 21 June, the shortest day of the year in the southern hemisphere and summer in the northern hemisphere
• Equinox is when Earth's axis is in line with the sun, the sun's rays fall directly onto the equator, and both hemispheres get the same amount of sunlight. Autumn equinox in the southern hemisphere is around 20 March
• Spring equinox is on 22 or 23 September, with days and nights of equal length (12 hours each) around the globe. It is autumn equinox in the northern hemisphere
• Summer solstice is when the sun's direct rays fall directly onto the Tropic of Capricorn, occurring on 21 or 22 December, the longest day of the year in the southern hemisphere
• Satellite


  Any object found in orbit around a star or planet in space. The moon is a satellite of the Earth and the Earth is a satellite of the sun
• Deforestation


  Cutting down of trees, leaving the land bare
• Meteorologist


  Scientists who study weather and climate