Plate Tectonics A Land in Motion Although we think of the land on Earth as being fixed and stable, it turns out that it is constantly moving. This movement is way too slow for us to notice, however, because it only moves between one to 6 inches per year. It takes millions of years for the land to move a significant amount.
Lithosphere The word lithosphere is derived from the word sphere, combined with the Greek word lithos, meaning rock. The lithosphere extends from the surface of Earth to a depth of about 44—62 mi 70— km.
This relatively cool and rigid section of Earth is believed to "float" on top of the warmer, non-rigid, and partially melted material directly below. Earth is made up of several layers.
The thickness of the crust varies. Under the oceansthe crust is only about 3—5 mi 5—10 km thick. Under the continents, however, the crust thickens to about 22 mi 35 km and reaches depths of up to 37 mi 60 km under some mountain ranges. Beneath the crust is a layer of rock material that is also solid, rigid, and relatively cool, but is assumed to be made up of denser material.
The combination of the crust and this upper part of the upper mantle, which are both comprised of relatively cool and rigid rock material, is called the lithosphere. This zone which lies directly below the lithosphere is called the asthenospherefrom the Greek word asthenes, meaning weak.
This motion creates stress in the rigid rock layers above it, forcing the slabs or plates of the lithosphere to jostle against each other, much like ice cubes floating in a bowl of swirling water. See also Continental drift theory; Earth planet ; Earth, interior structure Cite this article Pick a style below, and copy the text for your bibliography.The lithosphere is the solid, outer part of the Earth.
The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth’s structure.
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Covering The Lithosphere Although soil has many uses, it is really just a layer of dirt between the atmosphere and the bedrock in the tectonic monstermanfilm.com top layer of the planet is called the monstermanfilm.com is the loose stuff on the surface of the lithosphere.
Earth science is the study of planet Earth.
It covers all aspects of the planet from the deep inner core to the outer layers of the atmosphere. Plate tectonics, theory dealing with the dynamics of Earth’s outer shell—the lithosphere—that revolutionized Earth sciences by providing a uniform context for understanding mountain-building processes, volcanoes, and earthquakes as well as the evolution of Earth’s surface and reconstructing.
Kids learn about the Earth science subject of plate tectonics including major and minor plates, convergent, divergent, and transform boundaries.