"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 interaction of oceanic plates, including the formation of oceanic ridges and trenches, and the causes of earthquakes and volcanic activity.
Plate Tectonics: The study of the movement and interaction of the Earth's lithosphere plates.
Seafloor Spreading: The process of ocean floor creation as new crust is formed at mid-ocean ridges and pushes old crust away.
Subduction Zones: A tectonic boundary where one lithospheric plate is forced underneath another into the Earth's mantle.
Mid-Ocean Ridges: A continuous chain of undersea volcanoes and mountains that circles the globe, created by divergent plate boundary forces.
Volcanoes: An opening in the Earth's surface formed by the upward movement of magma which solidifies in the form of lava.
Earthquakes: The vibrations caused by the sudden release of energy within the Earth's crust or mantle, resulting in seismic waves.
Tsunamis: A series of ocean waves caused by large-scale disturbances of the ocean, such as earthquakes, landslides, or volcanic eruptions.
Seamounts: Submerged volcanic mountains that rise from the ocean floor but do not reach the surface, often forming hotspots for biodiversity.
Oceanic Crust: The unique composition of the Earth's crust beneath the ocean basin, formed mainly of basalt and gabbro.
Continental Drift: The theory that the Earth's continents were once joined together in a single supercontinent and have since drifted apart over time.
Paleomagnetism: The study of the Earth's magnetic field and its relationship to the rocks and sediments that have been magnetized over time.
Geological Time Scale: A division of Earth's history into units of time based on major geological events and evolutionary milestones.
Tectonic Plates: Large pieces of the Earth's lithosphere that move horizontally across the surface of the planet, coming into contact with one another at plate boundaries.
Mantle Plumes: Columns of hot rock that rise from the Earth's mantle and may cause volcanic hotspots or other surface features.
Bathymetry: The measurement of the depth and underwater topography of the ocean floor using sonar and other instruments.
Divergent boundary: When two plates move away from each other.
Convergent boundary: When two plates move towards each other.
Transform boundary: When two plates slide past each other in opposite directions.
Subduction zone: When one plate sinks beneath another plate and forms a deep ocean trench.
Hotspots: When molten rock rises from deep within the mantle and creates a volcanic island or seamounts.
Oceanic spreading: A type of divergent boundary where new oceanic crust is formed by volcanic activity from a rift in the ocean floor.
"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."