How Many Tectonic Plates Are There?

By Antonia Čirjak on June 16 2020 in Geography

Tectonic plates are large segments that form the crust of our planet.
Tectonic plates are large segments that form the crust of our planet.
  • There are seventeen plates altogether, and out of those 17, seven are major while the other ten is considered minor.
  • The largest major plate is the Pacific Plate, with a surface size of 103, 300 000 square kilometers. This tectonic plate is found under the Pacific Ocean, and its majority is made up of oceanic crust.
  • All of the minor tectonic plates are smaller than 20 million square kilometers in size.
  • The largest minor plate is the Somali plate found around the east coast of Africa, and its size is 16,700,000 square kilometers.

Tectonic plates are large segments that form the crust of our planet. Ever since the plate tectonics theory became widely recognized in the middle of the 20th century, scientists have been researching these plates as much as they could. This theory explains how these plates move, researches their characteristics, and also gives us explanations on how earthquakes occur and how mountains are formed.

By revealing the existence of these plates, we managed to learn many important things about our planet. Tectonic plates are usually divided into two main groups, the major and minor plates. There are seventeen plates altogether, and out of those 17, seven are major while the other ten is considered minor.

Size is the main criteria by which we determine if a tectonic plate is considered major or minor. The size of major tectonic plates ranges from around 40 million to about 100 million square kilometers. On the other hand, the largest minor plate is only 16,700,000 square kilometers in size, while the smallest one measures at 1,100,000 square kilometers.

Major Plates

Seven tectonic plates are considered major. The largest one is the Pacific Plate, with a surface size of 103, 300 000 square kilometers. This tectonic plate is found under the Pacific Ocean, and its majority is made up of oceanic crust. This plate is responsible for the formation of the Hawaiian Islands, which were previously volcanoes.

The North American Plate is the second-largest tectonic plate with the surface of 75,900,000 square kilometers, and it makes up the majority of North America, a part of Siberia and the entirety of Greenland. It formed the large mountain range known as the Mid-Atlantic Ridge.

The Eurasian Plate contains the continents of Europe and Asia, and its size is 67,800,000 square kilometers. It is known for containing the Himalayan mountain range.

By revealing the existence of these plates, we managed to learn many important things about our planet.
By revealing the existence of these plates, we managed to learn many important things about our planet.

The fourth-largest major tectonic plate is the African Plate, which makes up Africa and parts of the ocean east from the continent. Its surface size is 61,300,000 square kilometers.

The Antarctic Plate is the next on the list, and as the name suggests, it is made up of the continent of Antarctica and its surrounding oceans. The size of this tectonic plate is 60,900,000 square kilometers.

The final two major plates are the Indo-Australian and the South American Plate, and their sizes are 58,900,000 and 43,600,000 square kilometers, respectively. The South American plate is notable for its volcanic activity.

Minor Plates

As previously mentioned, there are ten minor tectonic plates, but their impact on the structure of our planet is not that big. They are often not even shown on the maps that portray the structure of tectonic plates, and they do not take up significant portions of land for the most part. All of the minor tectonic plates are smaller than 20 million square kilometers in size. Still, they are all larger than 1 million square kilometers.

The Afar Triple Junction is located along a divergent plate boundary dividing the Nubian, Somali, and Arabian plates in Djibouti
The Afar Triple Junction is located along a divergent plate boundary dividing the Nubian, Somali, and Arabian plates in Djibouti

The largest minor plate is the Somali plate found around the east coast of Africa, and its size is 16,700,000 square kilometers. It is closely followed by the Nazca plate, which has a surface area of 15,600,000 square kilometers and is found in the eastern part of the Pacific Ocean.

The other minor plates are significantly smaller, with sizes ranging from 5,500,000 square kilometers to only 1,100,000 square kilometers. These are, in order, Philippine Sea Plate near the Philippines, the Nazca Plate, the Arabian Plate, the Caribbean Plate, the Cocos Plate, and finally, Caroline, Scotia, Burma, and New Hebrides Plate.

All tectonic plates vary in size greatly, but nearly all of them are somewhere around 60 miles thick. They form the crust of our planet, which is most often referred to as the lithosphere. An interesting thing about tectonic plates is that they are all always moving around, albeit extremely slowly. This movement causes major changes in the crust of our planet, such as the formation of volcanoes and earthquakes.

How Many Tectonic Plates Are There?

RankTectonic PlateTypeSize (Square Km)
1Pacific PlateMajor103,300,000
2North American PlateMajor75,900,000
3Eurasian PlateMajor67,800,000
4African PlateMajor61,300,000
5Antarctic PlateMajor60,900,000
6Indo-Australian PlateMajor58,900,000
7South American PlateMajor43,600,000
8Somali PlateMinor16,700,000
9Nazca PlateMinor15,600,000
10Philippine Sea PlateMinor5,500,000
11Arabian PlateMinor5,000,000
12Caribbean PlateMinor3,300,000
13Cocos PlateMinor2,900,000
14Caroline PlateMinor1,700,000
15Scotia PlateMinor1,600,000
16Burma PlateMinor1,100,000
17New Hebrides PlateMinor1,100,000

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