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Hub AI
Earth's crust AI simulator
(@Earth's crust_simulator)
Hub AI
Earth's crust AI simulator
(@Earth's crust_simulator)
Earth's crust
Earth's crust is its thick outer shell of rock, comprising less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper part of the mantle. The lithosphere is broken into tectonic plates whose motion allows heat to escape the interior of Earth into space.
The crust lies on top of the mantle, a configuration that is stable because the upper mantle is made of peridotite and is therefore significantly denser than the crust. The boundary between the crust and mantle is conventionally placed at the Mohorovičić discontinuity, a boundary defined by a contrast in seismic velocity.
The temperature of the crust increases with depth, reaching values typically in the range from about 700 to 1,600 °C (1,292 to 2,912 °F) at the boundary with the underlying mantle. The temperature increases by as much as 30 °C (54 °F) for every kilometer locally in the upper part of the crust.
The crust of Earth is of two distinct types:
The average thickness of the crust is about 15–20 km (9.3–12.4 mi).
Because both the continental and oceanic crust are less dense than the mantle below, both types of crust "float" on the mantle. The surface of the continental crust is significantly higher than the surface of the oceanic crust, due to the greater buoyancy of the thicker, less dense continental crust (an example of isostasy). As a result, the continents form high ground surrounded by deep ocean basins.
The continental crust has an average composition similar to that of andesite, though the composition is not uniform, with the upper crust averaging a more felsic composition similar to that of dacite, while the lower crust averages a more mafic composition resembling basalt. The most abundant minerals in Earth's continental crust are feldspars, which make up about 41% of the crust by weight, followed by quartz at 12%, and pyroxenes at 11%.
All the other constituents except water occur only in very small quantities and total less than 1%.
Earth's crust
Earth's crust is its thick outer shell of rock, comprising less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper part of the mantle. The lithosphere is broken into tectonic plates whose motion allows heat to escape the interior of Earth into space.
The crust lies on top of the mantle, a configuration that is stable because the upper mantle is made of peridotite and is therefore significantly denser than the crust. The boundary between the crust and mantle is conventionally placed at the Mohorovičić discontinuity, a boundary defined by a contrast in seismic velocity.
The temperature of the crust increases with depth, reaching values typically in the range from about 700 to 1,600 °C (1,292 to 2,912 °F) at the boundary with the underlying mantle. The temperature increases by as much as 30 °C (54 °F) for every kilometer locally in the upper part of the crust.
The crust of Earth is of two distinct types:
The average thickness of the crust is about 15–20 km (9.3–12.4 mi).
Because both the continental and oceanic crust are less dense than the mantle below, both types of crust "float" on the mantle. The surface of the continental crust is significantly higher than the surface of the oceanic crust, due to the greater buoyancy of the thicker, less dense continental crust (an example of isostasy). As a result, the continents form high ground surrounded by deep ocean basins.
The continental crust has an average composition similar to that of andesite, though the composition is not uniform, with the upper crust averaging a more felsic composition similar to that of dacite, while the lower crust averages a more mafic composition resembling basalt. The most abundant minerals in Earth's continental crust are feldspars, which make up about 41% of the crust by weight, followed by quartz at 12%, and pyroxenes at 11%.
All the other constituents except water occur only in very small quantities and total less than 1%.
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