Geography Notes Chapter 2 Let us Use the Graticule Class 6 Maharashtra Board

1. What is a Graticule?

• The graticule is a network of latitude and longitude lines on the globe or a map.
• It helps us find the exact location of any place on Earth.
• A location is described using one latitude and one longitude.

2. How to Describe the Location of a Place?

• To find the location of a city, country, or region, we use latitudes and longitudes.
• Example: Delhi is located at 28° 36′ 50” N latitude and 77° 12′ 3” E longitude.
• Every place has a unique latitude and longitude.

3. How to Describe the Extent of a Region?

• The extent of a country or region is given using:
  • Two latitudes (northernmost and southernmost points).
  • Two longitudes (easternmost and westernmost points).

Example:

• • Australia’s extent: 10°30′ S to 43°39′ S latitude, 113° E to 153° E longitude.

4. How to Describe the Extent of a Road, River, or Linear Feature?

• The extent of a road or river is described by giving:
  • Latitude and longitude of the starting point.
  • Latitude and longitude of the ending point.

Example:

• • River Nile in Africa:
    • Starts at Lake Victoria (0° 45′ 21” S, 33° 26′ 18” E).
    • Ends at Mediterranean Sea near Alexandria (31° 12′ N, 29° 55′ 07” E).

5. Important Parallels of Latitude

• Parallels are imaginary horizontal lines on Earth.
• Important parallels:
  1. Equator (0° latitude) → Divides Earth into Northern and Southern Hemispheres.
  2. Tropic of Cancer (23.5° N) → Northern limit of the sun’s perpendicular rays.
  3. Tropic of Capricorn (23.5° S) → Southern limit of the sun’s perpendicular rays.
  4. Arctic Circle (66.5° N) → Beyond this, the sun is visible for 24 hours in summer.
  5. Antarctic Circle (66.5° S) → Beyond this, the sun is visible for 24 hours in summer.
  6. North Pole (90° N) & South Pole (90° S) → The extreme ends of the Earth.

6. Important Meridians of Longitude

• Meridians are imaginary vertical lines on Earth.
• Important meridians:
  1. Prime Meridian (0° longitude) → Divides Earth into Eastern and Western Hemispheres.
  2. 180° Meridian (International Date Line) → Opposite the Prime Meridian, changes the date when crossed.
  3. Other meridians: 90° E, 90° W, 45° E, 45° W, 135° E, 135° W.

7. Time and the Prime Meridian

• The Prime Meridian (0° longitude) is used to measure time worldwide.
• The time at this meridian is called Greenwich Mean Time (GMT).
• Countries have different time zones based on their longitude.

8. Why is the Graticule Important?

• It helps to find locations using latitudes and longitudes.
• It is used in navigation, GPS, and map reading.
• It helps in dividing the Earth into climate zones.
• It helps in understanding day and night durations in different regions.