Plate Tectonics and Earth's Surface

Front

Plate Tectonics Noun

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[playt tek-ton-iks]

Back

Plate Tectonics

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The scientific theory that Earth's lithosphere is broken into distinct plates that are in slow, constant motion.

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Example: Tectonic plates move slowly, causing Earth's surface to change.

Front

Lithosphere Noun

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[lith-oh-sfeer]

Back

Lithosphere

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The rigid outer part of the Earth, which is composed of the crust and the upper portion of the mantle.

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Example: The image shows Earth's layers, focusing on the crust and upper mantle, which form the lithosphere.

Front

Tectonic Adjective

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[tek-ton-ik]

Back

Tectonic

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Relating to the structure of Earth's crust and the large-scale processes which take place within it.

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Example: Arrows show how Earth's crust layers move, explaining tectonic activity.

Front

Theory Noun

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[thee-uh-ree]

Back

Theory

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A well-substantiated explanation of some aspect of the natural world that is supported by a vast body of evidence.

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Example: The image illustrates the scientific method, which is used to develop theories based on evidence.

Front

Oceanic Crust Noun

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[oh-shee-an-ik krust]

Back

Oceanic Crust

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The relatively thin, dense part of Earth's crust that underlies the ocean basins and is basaltic in composition.

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Example: The image shows oceanic crust forming at a divergent boundary with magma rising between plates.

Front

Continental Crust Noun

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[kon-tuh-nen-tl krust]

Back

Continental Crust

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The relatively thick, less dense part of Earth's crust that forms the large landmasses known as continents.

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Example: The image shows the continental crust as the thick, less dense part of Earth's crust forming the continents.

Front

Convection Noun

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[kun-vek-shun]

Back

Convection

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The movement caused within a fluid by the tendency of hotter, less dense material to rise and colder material to sink.

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Example: Warm water rises and cool water sinks, creating a circular motion in the pot.

Front

Convection Currents Noun

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[kun-vek-shun kur-ents]

Back

Convection Currents

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The slow circulation of material in Earth's mantle, caused by heat, that drives the movement of tectonic plates.

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Example: Heating water in a pot shows convection currents, similar to Earth's mantle.

Front

Pangaea Noun

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[pan-jee-uh]

Back

Pangaea

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A hypothetical supercontinent that included all current landmasses, believed to have existed before the continents broke apart.

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Example: The image shows Pangaea, a supercontinent with all current landmasses joined together.

Front

Plate Boundary Noun

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[playt bown-dree]

Back

Plate Boundary

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The region where two or more of the Earth's tectonic plates meet and interact with one another.

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Example: Two tectonic plates collide, forming mountains at a convergent boundary.