Question

How many major tectonic plates are there on earth?
A. 5
B. 7
C. 8
D. 10

Answer 1

Hint: Tectonic plates are huge slabs of solid rocks of irregular shapes. There are both continental and oceanic tectonic plates. These plates are responsible for the formation of many landform features. These plates float on a semi-fluid present beneath the earth surface, known as the asthenosphere.

Complete Answer:
The major tectonic plates comprise most of the continents and the Pacific Ocean. In total there are seven major tectonic plates on the earth surface which covers an area greater than 20 million sq. km. The seven major tectonic plates are:
African Plate: This plate stretches from west of Africa to the East African Rift and covers an area of about 61,300,000 sq. km.
Antarctic Plate: This plate consists of the continent of Antarctica and extends outwards under the nearby ocean and covers an area of about 60,900,000 sq. km.
Eurasian Plate: This is a plate that consists most part of the continents of Europe and Asia and covers an area of about 67,800,000 sq. km.
Indo-Australian Plate: This is one of the most important tectonic plates of the earth’s surface. This is formed by the combination of the Indian and Australian plates covering an area of about 58,900,000 sq. km.
North American Plate: This is a large tectonic plate consisting of North America, Greenland and parts of siberia. This plate covers an area of about 75,900,000 sq. km.
Pacific Plate: This is an oceanic plate under the Pacific Ocean that covers an area of about 103,300,000 sq. km.
South American Plate: This is a plate which consists of South America and a large part of the south Atlantic and covers an area of about 43,600,000 sq. km.
Therefore, option B, which says there are 7 tectonic plates on the earth is the correct answer.

Note: These plates are continuously in motion which is responsible for many earth movements. The geoscientific community accepted the plate tectonic theory after the theory of sea-floor spreading was accepted in the late 1950s and early 1960s.