About Tectonic Plates
Tectonic Plates are huge slabs of solid rocks of irregular shapes. Tectonic Plate is also known as Lithospheric Plates as it is composed of continental and oceanic lithosphere. The size of the various plates vary from a small few 100 kms to thousands of kms. Plate thickness also ranges from less than 15 km for young oceanic lithosphere to more than about 200 km for old continental lithosphere. The Pacific, North American and Antarctic Plates are among the largest tectonic plates.
Tectonic plates developed very early in the Earth's 4.6-billion-year history and have continued to drift about on the surface since their formation billions of years ago and moving like dashing cars repeatedly bumping together, pushing with pressure and then breaking or separating. Boundaries between individual plates are not mostly visible as they are under the oceans. GEO satellites are used to map the boundaries of the plates. Earthquake and volcanic activity is concentrated near these boundaries.
Geological theories state that the variations in plate thickness compensates the imbalance of the weight and density of lighter but thicker continental crust (about 100 km) composed of basaltic rocks and the heavier but thinner oceanic crust (about 5 km thick) composed of granitic rocks.
Tectonic Plates are huge slabs of solid rocks of irregular shapes. Tectonic Plate is also known as Lithospheric Plates as it is composed of continental and oceanic lithosphere. The size of the various plates vary from a small few 100 kms to thousands of kms. Plate thickness also ranges from less than 15 km for young oceanic lithosphere to more than about 200 km for old continental lithosphere. The Pacific, North American and Antarctic Plates are among the largest tectonic plates.
Tectonic plates developed very early in the Earth's 4.6-billion-year history and have continued to drift about on the surface since their formation billions of years ago and moving like dashing cars repeatedly bumping together, pushing with pressure and then breaking or separating. Boundaries between individual plates are not mostly visible as they are under the oceans. GEO satellites are used to map the boundaries of the plates. Earthquake and volcanic activity is concentrated near these boundaries.
Geological theories state that the variations in plate thickness compensates the imbalance of the weight and density of lighter but thicker continental crust (about 100 km) composed of basaltic rocks and the heavier but thinner oceanic crust (about 5 km thick) composed of granitic rocks.