"Plate tectonics is the scientific theory that Earth's lithosphere comprises a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago."
The study of the movement and interactions of the Earth's lithospheric plates and how they impact geological processes.
Continental drift: A theory proposed by Alfred Wegener, suggesting that continents were once joined together in a single landmass and have since drifted apart.
Seafloor spreading: The process of new oceanic crust being formed at mid-ocean ridges and spreading outwards.
Plate boundaries: The boundaries between two or more tectonic plates, including divergent, convergent, and transform boundaries.
Volcanoes: Geological features that form from the eruption of molten rock (magma) onto the earth's surface.
Earthquakes: Sudden movements of the earth's crust caused by tectonic plate movement.
Rift zones: Areas where the earth's crust is being pulled apart, often resulting in the formation of a new ocean basin.
Subduction zones: Areas where one tectonic plate is forced beneath another, resulting in the formation of volcanic arcs and deep ocean trenches.
Hotspots: Areas of the earth's surface where molten rock rises from deep within the mantle and creates volcanic activity.
Mantle convection: The process by which heat from the earth's core causes convective currents within the mantle, driving plate tectonics.
Geological time scale: A timeline that organizes and divides the history of the earth into different periods based on geological events and the evolution of life.
Divergent Plate Boundary: This occurs where two plates move away from each other. As they move away, the space between them is filled with magma, leading to the formation of a new crust.
Convergent Plate Boundary: This occurs where two plates move towards each other, causing one to be subducted (pushed underneath) the other. This results in the formation of mountain ranges as well as volcanoes and earthquakes.
Transform Plate Boundary: This occurs where two plates slide past each other. The movement results in the formation of faults that cause earthquakes.
Subduction Zones: This happens when a denser oceanic plate slides beneath a lighter continental plate at a convergent boundary. This results in volcanic activity and can cause large earthquakes.
Rift Valley: This is a type of divergent boundary that occurs on land. It results in the formation of a valley due to the pulling apart of two plates.
"The model builds on the concept of continental drift, an idea developed during the first decades of the 20th century."
"Plate tectonics came to be accepted by geoscientists after seafloor spreading was validated in the mid-to-late 1960s."
"Earth's lithosphere is broken into seven or eight major plates."
"Where the plates meet, their relative motion determines the type of plate boundary: convergent, divergent, or transform."
"Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries."
"The relative movement of the plates typically ranges from zero to 10 cm annually."
"Tectonic plates are composed of the oceanic lithosphere and the thicker continental lithosphere, each topped by its own kind of crust."
"Along convergent plate boundaries, the process of subduction, or of one plate moving under another, carries the edge of one plate down under the other plate and into the mantle."
"The lost surface is balanced by the formation of new oceanic crust along divergent margins by seafloor spreading."
"This process of plate tectonics is also referred to as the conveyor belt principle."
"Tectonic plates are able to move because Earth's lithosphere has greater mechanical strength than the underlying asthenosphere."
"Plate movement is driven by a combination of the motion of the seafloor away from spreading ridges due to variations in topography and density changes in the crust."
"At subduction zones, the relatively cold, dense oceanic crust sinks down into the mantle forming the downward convecting limb of a mantle cell. This is the strongest driver of the plates."
"The relative importance of other proposed factors such as active convection, upwelling and flow inside the mantle, and tidal drag of the moon, and their relationship to each other is still the subject of debate."