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The Persistence of Tectonics: Directed by Joe Ann Fogle. With Amy Brenneman, Dan Futterman, Richard T. Jones, Jessica Tuck. Maxine refuses to cook for Thanksgiving the 40th year in a row and is most skeptic when Amy announces she'll cook instead to give Lauren a good first one in Hatford, when her dad Michael Cassidy is visiting; they agree to formalize their divorce.
- (42)
- Drama
- Joe Ann Fogle
- 1999-11-23
Oct 19, 2023 · Colliding tectonic plates created mountain ranges, and a shift in global climate allowed glaciers to spread as far as the Equator. A new supercontinent named Pannotia formed in the south polar region. Tectonic plates, the massive slabs of Earth’s lithosphere that help define our continents and ocean, are constantly on the move.
Feb 10, 2024 · The size and shape of these plates continually change over geological time due to the dynamic nature of plate tectonics. The thickness of tectonic plates also varies, but generally they range from about 100 kilometers (62 miles) to 200 kilometers (124 miles) thick.
Mar 7, 2024 · Plate tectonics is a scientific theory that explains how major landforms are created as a result of Earth’s subterranean movements. The theory, which solidified in the 1960s, transformed the earth sciences by explaining many phenomena, including mountain building events, volcanoes, and earthquakes. In plate tectonics, Earth’s outermost ...
- Overview
- Principles of plate tectonics
German meteorologist Alfred Wegener is often credited as the first to develop a theory of plate tectonics, in the form of continental drift. Bringing together a large mass of geologic and paleontological data, Wegener postulated that throughout most of geologic time there was only one continent, which he called Pangea, and the breakup of this continent heralded Earth’s current continental configuration as the continent-sized parts began to move away from one another. (Scientists discovered later that Pangea fragmented early in the Jurassic Period.) Wegener presented the idea of continental drift and some of the supporting evidence in a lecture in 1912, followed by his major published work, The Origin of Continents and Oceans (1915).
Read more below: Development of tectonic theory
Pangea
Learn more about Pangea.
What is the cause of plate tectonics?
Although this has yet to be proven with certainty, most geologists and geophysicists agree that plate movement is caused by the convection (that is, heat transfer resulting from the movement of a heated fluid) of magma in Earth’s interior. The heat source is thought to be the decay of radioactive elements. How this convection propels the plates is poorly understood. Some geologists argue that upwelling magma at spreading centres pushes the plates, whereas others argue that the weight of a portion of a subducting plate (one that is forced beneath another) may pull the rest of the plate along.
In essence, plate-tectonic theory is elegantly simple. Earth’s surface layer, 50 to 100 km (30 to 60 miles) thick, is rigid and is composed of a set of large and small plates. Together, these plates constitute the lithosphere, from the Greek lithos, meaning “rock.” The lithosphere rests on and slides over an underlying partially molten (and thus weaker but generally denser) layer of plastic partially molten rock known as the asthenosphere, from the Greek asthenos, meaning “weak.” Plate movement is possible because the lithosphere-asthenosphere boundary is a zone of detachment. As the lithospheric plates move across Earth’s surface, driven by forces as yet not fully understood, they interact along their boundaries, diverging, converging, or slipping past each other. While the interiors of the plates are presumed to remain essentially undeformed, plate boundaries are the sites of many of the principal processes that shape the terrestrial surface, including earthquakes, volcanism, and orogeny (that is, formation of mountain ranges).
The process of plate tectonics may be driven by convection in Earth’s mantle, the pull of heavy old pieces of crust into the mantle, or some combination of both. For a deeper discussion of plate-driving mechanisms, see Plate-driving mechanisms and the role of the mantle.
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Oct 24, 2022 · Evidence of when plate tectonics started is hard to come by because the oldest pieces of crust are thrust into the interior mantle, never to resurface. Only 5 percent of all rocks on Earth are older than 2.5 billion years old, and no rock is older than about 4 billion years.
Dec 1, 2021 · Abstract. The theory of plate tectonics is widely accepted by scientists and provides a robust framework with which to describe and predict the behavior of Earth’s rigid outer shell – the lithosphere – in space and time. Expressions of plate tectonic interactions at the Earth’s surface also provide critical insight into the machinations ...
