"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."
A brief history of the scientific discovery of plate tectonics and the basic concepts behind the theory.
Continental drift: This is the hypothesis that the continents have moved over time and were once all connected.
Seafloor spreading: The theory that new oceanic crust is formed at mid-ocean ridges and separates the older oceanic crust farther from the ridge.
Plate boundaries: The interactions between tectonic plates that can form different types of boundaries (convergent, divergent, and transform).
Volcanoes: A geological feature that occurs at subduction zones and rift valleys, and is formed when magma reaches the surface.
Earthquakes: A sudden movement of the Earth's crust caused by the release of energy stored in rocks.
Subduction zones: These occur when a denser oceanic plate collides with a less dense continental plate and is forced beneath it into the mantle.
Mid-ocean ridges: These are underwater mountain ranges where new oceanic crust is formed.
Plate tectonic history: The story of how Earth's tectonic plates have moved over time, leading to the formation of continents, mountains, and other geological features.
Mantle convection: The motion of hot, molten material in the Earth's mantle that helps drive tectonic plate movement.
Plate tectonic models: The many different ways scientists have tried to explain how plates move, often using computer simulations and complex mathematical formulas.
Historical Introduction: This type of introduction provides a brief history of the study of plate tectonics, highlighting the key discoveries and scientists who contributed to its development.
Geological Introduction: This type of introduction describes the basic geological features of the Earth's surface and how they relate to plate tectonics, such as continents, mountains, and ocean basins.
Seismic Introduction: This type of introduction focuses on the seismic activity and earth movements associated with plate tectonics, such as earthquakes, volcanic eruptions, and tsunamis.
Geographic Introduction: This type of introduction examines how plate tectonics affects global geography and how the movement of tectonic plates has created and continues to create land masses, ocean basins, and other features.
Lithospheric Introduction: This type of introduction discusses the structure and composition of the Earth's lithosphere, which is made up of tectonic plates, and how this impacts plate tectonics.
Plate Boundary Introduction: This type of introduction explores the different types of plate boundaries, including divergent, convergent, and transform boundaries, and how they form and interact.
Paleontological Introduction: This type of introduction examines the paleontological evidence that supports plate tectonic theory, such as the distribution of fossils and the evolution of species.
Geodynamic Introduction: This type of introduction explores the mechanics of plate tectonics, including the driving forces behind plate movement, the processes of subduction and crustal deformation, and the role of mantle convection.
Astrobiological Introduction: This type of introduction considers plate tectonics in the context of the search for life on other planets, exploring how plate tectonics shapes the habitability of Earth and other planets.
Environmental Introduction: This type of introduction focuses on the environmental implications of plate tectonics, including natural hazards such as earthquakes and volcanoes, and the impact of plate tectonics on climate and ocean currents.
"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."