Form of the Earth

Axis and Direction of Rotation

The Earth rotates about an imaginary line called the polar axis, which passes through the North Geographic Pole (True North) and the South Geographic Pole (True South).

Looking down on the Earth from above the North Pole, the Earth rotates in an anti-clockwise direction.

Geographic and Magnetic Poles

The Earth has a magnetic field which influences the direction of a freely suspended magnetic compass needle.

The magnetic poles are known as the North Magnetic Pole and South Magnetic Pole. They are not in the same locations as the geographic poles and their positions change over time.

A magnetic compass aligns itself with the Earth's magnetic field and indicates Magnetic North, which is the datum used for measuring magnetic directions.

The Equator

The Equator is an imaginary line around the Earth, equidistant from the North and South Poles. It divides the Earth into the Northern Hemisphere and Southern Hemisphere.

The Equator:

• is 0° latitude,
• is the datum from which latitude is measured, and
• is a great circle.

Parallels of Latitude

Latitude is the angular distance north or south of the Equator, measured along a meridian of longitude.