👉 Globe is a true model of the earth.
👉 Globe is the true miniature model of the Earth.
👉 On the globe, countries, continents, and oceans are shown in their correct size.
👉 A needle is fixed through the globe in a tilted manner, which is called its axis.
👉 The globe can be moved around this needle from west to east just as the earth moves. But in the real earth has no such needle it moves around its axis, which is an imaginary line.
👉 Two points on the globe through which the needle passes are two poles-NORTH POLE AND SOUTH POLE.
👉 The equator is an imaginary circular line on the globe.
👉 It divides the globe into two equal parts.
👉 The northern half of the earth is known as the Northern Hemisphere and the southern half is known as the Southern Hemisphere.
👉 They are both equal halves.
👉 It is a very important reference point to locate places on the earth.
👉Latitudes are parallel circular lines from the equator up to the poles.
👉Latitudes are measured in degrees.
👉The equator represents the Zero degree latitude.
Important Paralles of Latitudes:
There are four important parallels of latitudes-
(1) Tropic of Cancer(23.5 degrees N) in the Northern Hemisphere
(2) Tropic of Capricorn(23.5 degrees S) in the Southern Hemisphere
(3) Arctic Circle at 66.5 degrees north of the equator
(4) Antarctic Circle at 66.5 degrees south of the equator
Heat Zones of the Earth:
👉Heat zones are the different zones of the earth, where the sun’s rays fall differently so that it causes different climate patterns.
👉 These are the Torrid Zone, the two Temperate Zones, and the two frigid Zones.
👉This zone receives the maximum heat.
👉This zone is lies between the Tropic of cancer and the Tropic of Capricorn.
👉 The mid-day sun is exactly overhead at least once a year on all latitudes between this zone.
👉These zones receive Moderate temperatures because the angle of the sun’s rays goes on decreasing towards the poles.
👉 These zones are bounded by the Tropic of cancer and Arctic Circle in the Northern Hemisphere, and the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere.
👉Areas lying between the Arctic Circle and the North Pole in the Northern Hemisphere and the Antarctic Circle and the South Pole in the Southern Hemisphere, are very cold. It is because here the sun does not rise much above the horizon. Therefore, its rays are always slanting and provide less heat. These are, therefore, called Frigid Zones.
👉The distance between them is measured in ‘degrees of longitudes’.
👉 All meridians are of equal length.
👉 The meridians passed through Greenwich, where the British Royal Observatory is located. This meridian is called the Prime Meridian.
👉 The value of Prime Meridian is 0° longitude and from it, we count 180° eastward as well as 180° westward.
👉 The Prime Meridian and 180° meridian divide the earth into two equal halves, the Eastern Hemisphere and the Western Hemisphere.
Longitude And Time:
👉When the Prime Meridian of Greenwich has the sun at the highest point in the sky, all the places along this meridian will have mid-day or noon.
👉 We know that the Earth rotates from West to East, those places east of Greenwich will be ahead of Greenwich time and those to the west will be behind it.
👉 The earth rotates 360° in about 24 hours, which means 15° = 1 hour, 1° = 4 minutes.
👉 The local time of places which are on different meridians are bound to differ so it is necessary to adopt the local time of some central meridian of a country as the standard time for the country.
👉 In India, the longitude of 82° 30’E is treated as the standard meridian.
👉 It is also known as the Indian Standard Time (IST).
👉 Some countries have a great longitudinal extent and so they have adopted more than one standard time.