Let us Use the Graticule Class 6 Geography Notes Maharashtra State Board
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).
Important Parallels and Meridian
Let us get acquainted with some important parallels and meridians.
All places between 23° 30′ north and south of the 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 the equator are called the 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 (the sun is 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 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 of 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.
Vatican City is known as the smallest country in the world. It is spread over an area of 0.44 sq. km. This country is located in Italy on the Italian peninsula. See the latitudinal and longitudinal extent of this country in the figure.
From west to east and also from north to south, there is no difference in the degrees or minutes of latitude or longitude but the difference is only in seconds. From this, you will get an idea about the use of the smaller units of minutes and seconds in angular measurements.
Good Maharashtra State Board Class 6 Geography Notes Let us Use the Graticule can simplify complex concepts and make studying more efficient.