The Earth’s lithosphere is divided into rigid sections known as plates, which float and move horizontally over the semi-molten asthenosphere in the mantle.
Types of Plate Tectonics
1. Continental Plates: These plates are made up of the continental crust, commonly called “sial.”
2. Oceanic Plates: These plates consist of oceanic crust, referred to as “sima.”
Classification Based on Size
Lithospheric plates are categorized further based on their size:
Major Lithospheric Plates
- Antarctic Plate: Covers Antarctica and its surrounding oceanic areas.
- North American Plate: Comprises the western Atlantic seabed, separated from the South American Plate along the Caribbean region.
- South American Plate: Includes the western Atlantic seabed and is separated from the North American Plate near the Caribbean region.
- Pacific Plate: Occupies a large portion of the Pacific Ocean basin.
- Indo-Australian Plate: Encompasses the landmasses of India, Australia, and New Zealand.
- African Plate: Covers the African continent and adjacent parts of the eastern Atlantic Ocean.
- Eurasian Plate: Includes Europe, Asia, and their neighboring oceanic areas.
Minor Lithospheric Plates
- Cocos Plate: Positioned between Central America and the Pacific Plate.
- Nazca Plate: Located between South America and the Pacific Plate.
- Arabian Plate: Primarily comprises the landmass of Saudi Arabia.
- Philippine Plate: Lies between the Asiatic Plate and the Pacific Plate.
- Caroline Plate: Found between the Philippine Plate and Indian Plate, north of New Guinea.
- Fiji Plate: Situated to the northeast of Australia.
- Juan de Fuca Plate: Found southeast of the North American Plate.
Previous Year Questions
- Which of the following phenomena might have influenced the evolution of organisms?(2014)
- Continental drift
- Glacial cycles
Correct Answer: (c) Both 1 and 2
- Consider the following factors responsible for dynamic changes on the Earth’s surface:(2013)
- Electromagnetic radiation
- Geothermal energy
- Gravitational force
- Plate movements
- Rotation of the Earth
- Revolution of the Earth
Correct Answer: (d) 1, 2, 3, 4, 5, and 6
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