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

Let Us Use The Graticule

Make Friends With The Globe!

Observe the globe and answer the following.

What are the horizontal lines on the globe called?

List the continents and oceans through which the equator passes.

Encircle the intersection of 0° meridian and 0° parallel on the globe.

The Equator and the Prime Meridian are labelled in degrees in figure 2.2. Can you write the values of other meridians and parallels?

Which oceans are spread in all the four hemispheres?

Which continents are spread in all the four hemispheres?

At which two parallels do all the meridians converge?

When we talk about various places, regions, rivers, roads, etc. we are actually talking with reference to the earth. The location of a place, the extent of a region and the extent of any linear feature can be described precisely with the help of parallels and meridians. Let us see how to use the graticule for this purpose.

Verify the following description with the help of a world map or a globe in the school.

While describing the location of a place, we need to consider only one parallel and one meridian, e.g., Delhi is located at 28°36' 50'' N latitude and 77°12' 3'' E longitude.

For describing the extent of a region we need to consider two parallels and two meridians at the extreme ends of the region. For example, the extent of Australia is described as 10°30' S to 43°39' S latitude and 113° E to 153° E longitude.

For describing the extent of linear features like a river, road etc., we need to consider the latitude and longitude of their terminal points. For example, the River Nile in Africa originates in Lake Victoria, flows north and meets the Mediterranean Sea near the city of Alexandria in Egypt. The location of Lake Victoria is 0° 45' 21''S latitude and 33°26' 18''E longitude. Similarly, the location of Alexandria is 31°12'N latitude and 29° 55'07''E longitude. These latitudes and longitudes are considered to describe the extent of the River Nile. This extent is from 0°45'S latitude and 33°26'E longitude (origin) to 31°12'N latitude and 29°55'E longitude (up to the mouth).

Teacher's Note

You can find your school's location using Google Maps. This is just like finding Delhi at 28°N and 77°E on a globe.

Exam Trick

Remember: One parallel and one meridian = Location of one place. Two parallels and two meridians = Extent of a region.

Points to Remember

Location needs one latitude and one longitude.
Extent of a region needs two latitudes and two longitudes.
Rivers and roads need the starting and ending points.
Graticule means the lines of latitude and longitude on a map.
Parallels are horizontal lines and meridians are vertical lines.

Make Friends With Maps!

Answer the following questions about location and extent with the help of figure 2.3.

Which latitude and longitude define the location of the capital of Brazil – Brasilia?

What would be the longitudinal extent of Brazil that spreads from 5° 15' N to 33° 45' S latitude?

In which hemispheres does Brazil extend in the north - south direction?

In which hemisphere does Brazil extend in the east - west direction?

Which parallels and meridians should be used to describe the extent of River Sao Francisco?

Describe the location of Marajo island using the graticule.

Teacher's Note

Brazil is a very big country in South America. We use two latitudes and two longitudes to show how big it is.

Exam Trick

When a question asks about extent, always write two latitudes and two longitudes. For location, write only one of each.

Points to Remember

Location of Brasilia needs its latitude and longitude.
Extent shows the size of a country from north to south and east to west.
Brazil is in both Northern and Southern hemispheres.
Island location is found using graticule like any other place.
Different regions need different degrees and minutes.

Important Parallels And Meridians

Let us get acquainted with some important parallels and meridians.

All places between 23° 30' north and south of equator receive perpendicular rays on two days in a year. Other areas of the earth never get perpendicular rays. The parallels at 23° 30' N and 23° 30' S of equator are called Tropic Of Cancer and Tropic Of Capricorn respectively.

The parallels at 66° 30' north and south of the equator are also important parallels. In the area between these two parallels, throughout the year, daytime lasts within the limit of 24 hours. These are called the Arctic Circle and the Antarctic Circle respectively.

Depending on the seasons, daytime (sun being visible in the sky) can be greater than 24 hours in the areas between the polar circles and the Poles. The maximum duration of the sun's appearance in the sky can be of six months at the Poles based on the seasons. During this period, the sun continues to move in a spiral on the horizon.

We have seen in Std V that the earth's axis is inclined. These important parallels arise because of its inclination by 23° 30'.

Due to the duration and intensity of sunlight, different temperature zones are formed on the earth. These zones give rise to pressure belts.

Variation in the intensity of sunlight leads to regional diversity in plant and animal life.

The 0° longitude or Prime Meridian is an important meridian. The main purpose of this is to fix the global standard time and coordinate the standard times of different countries. This meridian is also called as Greenwich Meridian. Global standard time is known as GMT – Greenwich Mean Time.

The 180° meridian is also important. From the Prime Meridian, other meridians are marked east and west up to 180°. The 180° meridian lies opposite to the Prime Meridian.

The International Date Line is marked with reference to this meridian.

The equator as well as all pairs of opposite meridians form Great Circles. Great Circles are used for finding the minimum distance between any two places on the surface of the earth.

Teacher's Note

India passes through the Tropic of Cancer. This is why India gets very hot in some areas and gets perpendicular sun rays twice a year.

Exam Trick

Remember: Tropic of Cancer is 23° 30' N. Arctic Circle is 66° 30' N. The difference is always 43°!

Points to Remember

Tropic of Cancer is at 23° 30' N latitude.
Tropic of Capricorn is at 23° 30' S latitude.
Arctic Circle is at 66° 30' N latitude.
Antarctic Circle is at 66° 30' S latitude.
Prime Meridian (0°) helps fix world standard time.

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