The understanding of parallels, latitude, longitude, and meridians is essential for accurately locating and identifying positions on the Earth’s surface. These geographic concepts form the foundation for navigating, mapping, and organizing global activities.
Parallel of Latitude| Class 11 Geography Practical Work
Parallels of Latitudes
Latitude is a geographic coordinate that specifies the north-south position of a point on the Earth’s surface. It is measured in degrees, minutes, and seconds of angle north or south of the equator. The equator is defined as 0° latitude, and the poles are located at 90° north (North Pole) and 90° south (South Pole) latitude, respectively.
Lines of latitude, also known as parallels, are imaginary horizontal lines drawn on maps and globes to indicate latitude values. These lines are parallel to the equator and are spaced evenly apart from each other. If parallels of latitude are drawn at intervals of one degree, there will be a total of 89 parallels in both the northern and southern hemispheres, excluding the equator. Including the equator, the total number of parallels will be 179.
The length of one degree of latitude (a one-degree arc of a meridian) is not constant across the Earth’s surface due to the Earth’s slightly ellipsoidal shape. However, if the Earth were a perfect sphere, the length of one degree of latitude would be a constant value. On average, the length of one degree of latitude is approximately 111 kilometers. This value is nearly consistent at different latitudes but varies slightly from the equator to the poles.
At the equator, one degree of latitude corresponds to approximately 110.6 kilometers, while at the poles, it is approximately 111.7 kilometers. This variation in length is due to the Earth’s oblate spheroid shape, where the distance from the center of the Earth to its surface is shorter at the poles and longer at the equator.
The latitude of a place can be determined using various methods, including measuring the altitude of the sun or observing the position of the Pole Star (Polaris) in the night sky. These methods involve astronomical observations and trigonometric calculations to determine the angle between the horizon and the celestial object, thereby determining the latitude of the observer’s location.
Drawing the Parallels of Latitudes
To draw parallels of latitude on a circle, follow these steps:
- Draw a circle representing the Earth’s surface. This circle will serve as the basis for drawing parallels of latitude.
- Divide the circle into two equal halves by drawing a horizontal line in the center. This horizontal line represents the equator, which is 0° latitude.
- Place a protractor on the circle in such a way that the 0° and 180° lines on the protractor coincide with the equator on the paper. This ensures that the protractor is aligned properly for accurate measurement of angles.
- To draw a parallel of latitude, such as 20°S (20 degrees south), locate two points on the lower half of the circle at an angle of 20° from the equator, one to the east and one to the west. Use the protractor to measure this angle accurately.
- The arms of the angle will intersect the circle at two points. Mark these points.
- Join the two marked points by drawing a line parallel to the equator. This line represents the parallel of latitude at 20°S.
- Repeat the same process to draw additional parallels of latitude at different angles, both north and south of the equator, as needed.
By following these steps, you can accurately draw parallels of latitude on a circle, representing different latitudinal lines on the Earth’s surface. This method allows you to visualize and understand the distribution of latitudes across the globe.
Major Parallel Lines
1. The Equator (0° Latitude):
– The Equator is the 0-degree latitude line that divides the Earth into the Northern and Southern Hemispheres.
– It is the largest parallel and is the reference point for measuring latitude.
2. The Tropic of Cancer (23.5°N Latitude):
– The Tropic of Cancer is the parallel line at 23.5 degrees north of the Equator.
– It marks the northernmost point where the sun can be directly overhead.
3. The Tropic of Capricorn (23.5°S Latitude):
– The Tropic of Capricorn is the parallel line at 23.5 degrees south of the Equator.
– It marks the southernmost point where the sun can be directly overhead.
4. The Arctic Circle (66.5°N Latitude):
– The Arctic Circle is the parallel line at 66.5 degrees north of the Equator.
– It marks the northernmost point where the sun can be seen above the horizon for 24 hours during the summer solstice.
5. The Antarctic Circle (66.5°S Latitude):
– The Antarctic Circle is the parallel line at 66.5 degrees south of the Equator.
– It marks the southernmost point where the sun can be seen above the horizon for 24 hours during the summer solstice.
6. The North Pole (90°N Latitude):
– The North Pole is the northernmost point on the Earth’s surface, located at 90 degrees north latitude.
7. The South Pole (90°S Latitude):
– The South Pole is the southernmost point on the Earth’s surface, located at 90 degrees south latitude.
Conclusion
The mastery of these fundamental geographical principles allows for the effective utilization of the Earth’s coordinate system, which underpins a wide range of applications, from weather forecasting and climate analysis to transportation and communication across the globe.
Parallels of Latitude-FAQs
What is the difference between parallels and meridians?
Parallels are the east-west running, latitude-measuring lines, while meridians are the north-south running, longitude-measuring lines on the Earth’s surface.
How are the heat zones on Earth defined by latitude?
The Earth is divided into the Torrid Zone (near the Equator), Temperate Zones (between the Tropics and Arctic/Antarctic Circles), and Frigid Zones (near the Poles) based on latitude.
What is the significance of the Horse Latitudes?
The Horse Latitudes are the subtropical high-pressure belts located around 30 degrees north and south of the Equator, known for their calm, dry conditions that were challenging for sailing ships in the past.
What is the purpose of the Prime Meridian and the International Date Line?
The Prime Meridian serves as the 0-degree longitude reference point, while the International Date Line marks the place where the date changes, roughly opposite the Prime Meridian.
How are time zones related to meridians of longitude?
Each time zone covers a 15-degree span of longitude, with the meridians used to define the boundaries between these time zones.