Revision Summary 00 GEO


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Revision Summary 00 GEO

  1. 1. planets starMilky seasons globe 1
  2. 2. Imaginary lines of latitude and longitude on the Earth Imaginary lines are drawn on maps to describe where places are on the Earth. positionsThese lines appear in the same positions on all maps The Earths axis goes through the centre of the Earth from the North Pole to the South Pole. The Earth rotates on this axis The lines of latitude are parallel circles that go horizontally around the Earth. They south indicate distance north or south from the Equator. The Equator is the middle line that divides the Earth into two equal parts. These two parts are Northern Hemisphere and the Southern Hemispheres The lines of longitude go vertically from pole to pole. Every point on Earth is measured iin n terms of how far east or west it is from theline of zero longitude. This line is called the Greenwich Meridian because it passesthrough Greenwich in England The movements of the Earth Celestial bodies move in the sky. For this reason, we know that the Earth andthe Moon move in the sky. This happens even if we cannot feel the movement. TheEarth has two movements, called orbit and rotation. orbit. The Earth is a planet which moves around the Sun. This movement is called orbit.The Earth takes 365 days and 6 hours (one year) to complete one orbit of the Sun.The amount of light and heat received form the Sun is not equal everywhere on Earthbecause of the Earths tilt. This causes different climates in different areas of theworld. It is also responsible for the changes in season during the year: spring, summer, 2
  3. 3. hemispheres.autumn and winter. The seasons happen at different times in the two hemispheres.When it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere. itself, rotation. When the Earth rotates on itself, the movement is called rotation. The Earthtakes 24 hours or one entire day, to rotate on itself. This movement causes us to night.have day and night. Because the Earth is round, the Sun can illuminate only one area of it. The other thearea of the planet is in the shade. It is day time in the area that the Sun isilluminating. It is night time in the area that is in the shade. When the Earth rotates,the area that is illuminated gradually gets darker. The area that is in the shadegradually gets illuminated. Maps, Maps, scale and projections A map is a two dimensional description of a specific area of land. Maps helpgeographers understand in a visual way, important things about the surface of theEarth. They have been used by humans for hundreds of years, but it is impossibility impossibilityof recreating the surface of a round planet on a flat map. Maps are not perfect! 3
  4. 4. Maps can represent a variety of information. This information includes things such roads, tourist attractions or towns. Something can help us understand maps. For example, title, legend, scale, geographic coordinates or projection. The objects on a map are represented using symbols. A symbol picture is a picture on the map that represents something in the real world. To read a map you need to understand compass directions(showing which way is up —North-), grid references (numbered squares), the maps key North-(the reader knows what the symbols on the map represent) and scale (the reader can (thetranslate distances shown on the map into distances on the ground). Make sure ground). theyou read the title of a map before you start to use it (eg land use or vegetation cover).This will give you a general idea about the information it stores. The scale below is for a 1:50,000 scale The scale is the proportion between the real size of map. At this scale, 1 cm on the map represents 50,000 cm on the ground the represented territory and the corresponding size on (= 500 m or 0.5 km) the map. For example, your map has a scale of 1:25 000, which means that every 1 cm on the map represents 25000 25000 of those same units of measurement on the ground (for example, 25000 cm = 250 metres). There 25000 are three common methods used by map makers to depict depict scale: graphic method and fractional method. 3- A map projection is any of many methods used to represent the 3-dimensional 2-surface of the Earth on a 2-dimensional plane in cartography. There are three map plane.projection types: cylindrical, cone and plane. 4