Yes, the Earth's mantle is divided into different layers. Specifically, it is commonly understood to be divided into the upper and lower mantle.
Divisions of the Mantle
The mantle, which lies between the Earth's crust and core, isn't a uniform layer. Instead, it exhibits variations in composition, temperature, and pressure that lead to distinct zones. The primary division is between the upper and lower mantle:
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Upper Mantle: Extends from the base of the crust down to approximately 660 kilometers (410 miles). Key features of the upper mantle include:
- The lithosphere: The rigid outer layer, comprising the crust and uppermost mantle.
- The asthenosphere: A partially molten layer beneath the lithosphere, which allows the tectonic plates to move.
- The transition zone: A region between 410 km and 660 km marked by significant changes in mineral structure due to increasing pressure.
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Lower Mantle: This extends from 660 kilometers down to the core-mantle boundary at approximately 2,900 kilometers. The lower mantle is hotter and under much greater pressure than the upper mantle. It's primarily composed of silicate perovskite.
While the upper and lower mantle are the major divisions, further subdivisions and complexities exist within these layers.
