The Mantle

84% of Earth's total vol The mantle is the mostly solid layer between the core and the surface layer, or crust. This layer extends nearly 3,000 kilometers beneath the Earth'surface. The upper mantle extends from the crust to a depth of 410 kilometers, and mostly solid but has malleable regions which contribute to tectonic activity. Within the upper and lower mantle exists the transition zone. This zone extends from 410 to 660 kilometers beneath the Earth'surface. Rocks in this region undergo structural changes, making them much more dense. The transition zone prevents large exchange of materials between the upper and lower mantle. Within the transition zone, there is an abundance of water existing as hydroxide, an ion formed from olivine acylicate. Crystals in this zone hold as much water as Earth's oceans combined. The lower mantle extends from 660 to 2,700 kilometers below the surface. It is much hotter and denser than the upper mantle and transition zone. Intense pressure keeps the lower mantle solid. Below the lower mantle is a shallow region called D-double prime. The thickness of this layer varies between the mantle and outer core. D-double prime has thick acc The core mantle boundary, or CMB, is called the Gutenberg discontinuity. There has yet to be any successful drilling of the mantle. However, geologists study this region by observing xenoliths, which are rocks trapped inside other rocks. They also observe seismic waves and mantle maps created from cutting edge technology. Wednesday, January 8th will look further into Earth's mantle, exploring the lithosphere and esthenosphere. Don't forget to tune into the monthly What's What on New Year's Day. In the meantime, please subscribe to Mr. Weather's World on YouTube for new videos in 2020. Happy holidays!