Earth's Axis and Rotation

Study Notes

The Earth's axis is an imaginary line that passes through the North and South Poles.
A globe is a model of the Earth, and it can be moved around its axis, just like the Earth.
The axis of the globe is like the needle of a knitting needle, and it passes through the North and South Poles.

The Equator is an imaginary circular line that divides the globe into two equal parts: the Northern Hemisphere and the Southern Hemisphere.
The Northern Hemisphere is the part of the Earth above the Equator, and the Southern Hemisphere is the part below the Equator.
The Equator is a very important reference point to locate places on the Earth.

Latitudes are measured in degrees, and they range from 0° at the Equator to 90° at the North and South Poles.
The Equator represents 0° latitude, and the North and South Poles represent 90° latitude.
Parallels of latitude are circles that run parallel to the Equator, and they are measured in degrees.
Longitudes are also measured in degrees, and they range from 0° at the Prime Meridian to 180° east and west.
The Prime Meridian is the reference point for measuring longitudes, and it is located at 0° longitude.

The Earth has three heat zones: the Torrid Zone, the Temperate Zones, and the Frigid Zones.
The Torrid Zone is located near the Equator and receives maximum heat because the sun's rays are directly overhead.
The Temperate Zones are located between the Tropic of Cancer and the Arctic Circle in the Northern Hemisphere, and between the Tropic of Capricorn and the Antarctic Circle in the Southern Hemisphere.
The Frigid Zones are located near the North and South Poles, and they are very cold because the sun's rays are always slanting.

A grid is a network of parallels of latitude and meridians of longitude.
The grid is used to locate points on the Earth by their latitude and longitude.
For example, Dhubri in Assam is located at 26° N latitude and 90° E longitude.
The location of a point can be found by finding the intersection of its latitude and longitude on the grid.