How Many Tectonic Plates Are There?

Tectonic plates are gigantic segments or pieces of the Earth's crust and uppermost mantle that together constitute the Lithosphere. Tectonic Plates are of two types, namely oceanic crust and continental crust that differ in composition. Tectonic plates are not fixed but move above the molten mantle below them.Tectonic plates form either divergent, transform, or convergent boundaries when they come in contact. Such boundaries are highly susceptible to earthquakes and volcanic eruptions. Orogeny also takes place at such boundaries. Tectonic plates are defined as major and minor plates depending on their size. There are a total of seven major tectonic plates which cover nearly 95% of the Earth's surface. 

Major Tectonic Plates By Size

Pacific Plate - 103,300,000 sq km 

The Pacific Plate is estimated to be 103,300,000 square kilometers in size. Found underneath the Pacific Ocean, it is the largest of all tectonic plates. Most of the Pacific Plate is made up of oceanic crust, except for areas around New Zealand and parts of California. The nature of the Pacific Plate was notably responsible for forming the islands of Hawaii. The Hawaiian Islands were originally volcanoes that rose above the water over millions of years to form landmasses. These volcanoes were formed at hot spots in the Pacific Plate. This tectonic plate hosts the Ring of Fire, an area on the floor of the Pacific Ocean where volcanic activity and earthquakes are most active.

North American Plate - 75,900,000 sq km 

The North American Plate is the world’s second-largest tectonic plate. It consists of both continental crust and oceanic crust. The plate’s continental crust is made up of most of North America and Iceland. The North American plate is responsible for the formation of the Mid-Atlantic Ridge, a mountain chain beneath the Atlantic Ocean. A few hot spots underneath the plate are responsible for active seismic activity, the most famous example of which may be the Yellowstone geyser. 

Eurasian Plate - 67,800,000 sq km 

The Eurasian Plate has an estimated area of 67,800,000 square kilometers. It is the third-largest of the major tectonic plates. Most of the continents of Europe and Asia are in the Eurasian Plate. Several geological formations can be found on this plate, the most prominent of which is the Himalayan Range. The Himalayan mountains formed as a result of the collision between the Eurasian Plate and the Indian Plate. The Eurasian Plate is a geologically active plate, with volcanoes and earthquakes occurring in its territory. 

African Plate - 61,300,000 sq km 

The African plate is the fourth largest tectonic plate with an estimated area of 61,300,000 square kilometers. Most of the African continent is on the African Plate. The African Plate also includes substantial parts of the Indian and Atlantic Oceans. The Plate is slowly splitting at the East African Rift Valley which runs from the Red Sea to Kenya. Notably, the Italian island of Sicily is also a part of the African Plate.

Antarctic Plate - 60,900,000 sq km 

The Antarctic Plate encompasses the entire continent of Antarctica, as well as the nearby oceans. It is the fifth-largest plate on earth. It is also the world’s southernmost plate. 

Indo-Australian Plate - 58,900,000 sq km 

The Indo-Australian Plate was formed out of a merger of the Australian and Indian plates millions of years ago. When the Eurasian Plate and the Indo-Australian plates collided many many years ago, the Himalayan mountains were formed. Some scientists, however, believe that the Indian Plate and the Australian Plate are separate plates, and have been so for millions of years. 

South American Plate - 43,600,000 sq km 

The South American Plate is a major tectonic plate that covers 43 million square kilometers including South America and the surrounding Atlantic Ocean. Tectonic activity at the boundary between the South American Plate and the Nazca Plate is held responsible for the volcanic activity and orogeny in the region.

Minor Tectonic Plates By Size

Somali Plate - 16,700,000 sq km 

The Somali Plate is a minor tectonic plate encompassing the African country of Somalia. Currently, the Somali Plate is moving away from continental Africa at a very small pace which equates to around 20 millimeters per annum. At this pace, Somalia may separate from Africa after millions of years, leading to the formation of a new continent and ocean. 

Nazca Plate - 15,600,000 sq km 

The second largest of all minor plates, the Nazca Plate, stretches for 15.6 square km off the western coast of South America, to the south of the much smaller Cocos Plate. 

Philippine Sea Plate - 5,500,000 sq km

The Philippine Sea Plate comprises of over 5 million square km of ocean space adjacent to the Philippines, in the Philippine Sea. The plate also touches upon both Taiwan and Japan in its northern reaches. 

Arabian Plate - 5,000,000 sq km

The Arabian Plate measures 5 million square km, mostly across the Arabian Peninsula. The plate also includes parts of the Levant. 

Caribbean Plate - 3,300,000 sq km 

The Caribbean Plate is found in the Caribbean Sea, as well as the island of Hispaniola, and Central America. It lies to the north of South America and south of the islands of Cuba and Jamaica. 

Cocos Plate - 2,900,000 sq km 

The Cocos Plate is a minor plate that stretches for 2.9 million square km. It is geographically located off the coast of western Central America. The plate is around 23 million years old, which is relatively young in tectonic plate terms. The formation of the Cocos Plate can be traced to seafloor spreading, which generally occurs at mid-ocean ranges. The shifting of the Cocos Plate underneath the North American Plate (these movements are called subduction) led to several earthquakes in recent times.

Caroline Plate - 1,700,000 sq km

The Caroline Plate is a minor plate found in South Asia. It is moving at a speed of around 87 mm every year.

Scotia Plate - 1,600,000 sq km

The Scotia Plate stretches for 1.6 square km just north of the Antarctic Plate. The majority of the plate is deeply submerged beneath the Scotia Sea.

Burma Plate - 1,100,000 sq km

As its name suggests, the Burma Plate encompasses the country of Burma(Myanmar).

New Hebrides Plate - 1,100,000 sq km

The New Hebrides Plate is found in the south Pacific Ocean, where it stretches for 1,100,000 square km. It is closest to the country of Vanuatu.

Bonus: Juan de Fuca Plate - 250,000 sq km 

The Juan de Fuca Plate is one of the smallest of tectonic plates. At only 205,000 square km, it is technically not a minor plate but a microplate - but it may be one of the world’s most notorious ones. The Juan de Fuca Plate is part of the infamous Ring of Fire, a zone responsible for volcanic activity, orogeny, and earthquakes.