# Competitive Exams: Measurement of the Earth

The earth's axis, or the imaginary line round which the earth rotates, is about 12, 712 kilometres long. It's upper and is called the North Pole while its lower end is known as the South Pole. The polar circumference of the earth is 40, 024 kilometres. Exactly mid-way between the two poles and dividing the surface of the globe into two halves-the Northern Hemisphere and the Southern Hemisphere-runs an imaginary line called the Equator. This is 40, 075 kilometres round. The area of the surface of the Earth is nearly 510 million square kilometres, while the volume of the globe is a little over a billion cubic kilometers.