plate tectonics

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plate tectonics

n.
1. (used with a sing. verb) A theory that explains the global distribution of geological phenomena such as seismicity, volcanism, continental drift, and mountain building in terms of the formation, destruction, movement, and interaction of the earth's lithospheric plates.
2. (used with a sing. or pl. verb) The dynamics of plate movement.

plate′-tec·ton′ic adj.

plate tectonics

n
(Geological Science) (functioning as singular) geology the study of the structure of the earth's crust and mantle with reference to the theory that the earth's lithosphere is divided into large rigid blocks (plates) that are floating on semifluid rock and are thus able to interact with each other at their boundaries, and to the associated theories of continental drift and seafloor spreading

plate′ tecton′ics


n.
a geologic theory that describes the earth's crust as divided into a number of rigid plates, movement of which accounts for such phenomena as continental drift and the distribution of earthquakes.
[1965–70]
plate′-tecton′ic, adj.

plate tectonics

In geology, a theory that the Earth's lithosphere (crust and upper mantle) is divided into a number of large, plate-like sections that move as distinct masses. See Notes at fault, Gondwanaland, See more at tectonic boundary.
Did You Know? Have you ever noticed that the Earth's continents seem to fit together like pieces of a puzzle? This observation is what led the German meteorologist Alfred Wegener to propose the theory of continental drift in 1915. Since rocks and fossils were found to match up in parts of different continents, it seemed that they must have once been joined, but no one could explain how such large landmasses could move so far apart. This problem was not solved until the 1960s, when the theory of plate tectonics was proposed. According to this theory, the continents move apart by riding piggyback on plates—huge slabs of the Earth's lithosphere—that are much larger than the continents themselves. The plates move like parts of a conveyor belt powered by huge convection currents of molten rock that many geologists believe is heated by the decay of radioactive elements deep within the Earth. Although they only move a few inches per year, over hundreds of millions of years the continents are carried thousands of miles. Along their boundaries, the plates crumple, scrape, or pull apart from one another, giving rise to volcanoes and earthquakes and creating and destroying rock on the ever-changing surface of the planet.

plate tectonics


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The study of how lithospheric plates move around.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.plate tectonics - the branch of geology studying the folding and faulting of the earth's crust
geomorphology, morphology - the branch of geology that studies the characteristics and configuration and evolution of rocks and land forms
Pangaea, Pangea - (plate tectonics) a hypothetical continent including all the landmass of the earth prior to the Triassic period when it split into Laurasia and Gondwanaland
References in periodicals archive ?
Up to now, it has only been possible to extrapolate, for example using land observations, whether the plate boundaries there are moving or locked.
relating the occurrence of earthquakes and volcanic activity to constructive and destructive plate boundaries;
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The country lies along the 'Pacific Ring of Fire,' home to several tectonic plate boundaries that stretch from Indonesia to the coast of Chile within a 40,000-km arc of seismic violence that triggers volcanic eruptions and unleashes earthquakes almost every day.
A spokesperson for the Department of the Environment said: "Larger earthquakes occur at plate boundaries but the closest plate boundary to Donegal is the mid-Atlantic ridge."
This leads to slower subduction, which may allow for mountains to grow at plate boundaries as the force of the two plates running into each other causes uplift.
Multiplet earthquakes are believed to happen when chunks of crust are stuck in faults, or plate boundaries have irregular shapes, meaning the tension is not fully released when a singular earthquake happens.
These forces do not simply move the plates around, they can also cause plates to rupture, forming a rift and potentially leading to the creation of new plate boundaries. The East African Rift system is an example of where this is currently happening.
'Most earthquakes do not occur along the plate boundaries, they are interpolated and that is why it has been a puzzle to geoscientist.
The most obvious mountain belts today (the Himalayas, the Alps and the Andes, for example) are situated at currently active plate boundaries. Others, such as the Caledonian mountains of the British Isles and Scandinavia, are the product of a plate collision that happened far in the geological past and have no present relationship to a plate boundary.
In fact this is similar to those occurring near the plate boundaries, in agreement with the geological observations.
Quakes at plate boundaries usually involve larger faults and thus release more energy, generating shaking over larger areas.