INTERIOR OF EARTH

INTERIOR OF EARTH

Earth is composed of three layers (major concentric zones). Their names are given below as:

Crust:

The crust is the outermost layer of Earth.

•      “Crust” describes the outermost shell of a terrestrial planet .Beneath the crust lies Mantle.

•      The between crust and mantle is called is the Moho boundary.

•      Just as the depth of the crust varies so as the temperature and pressure

•      The crust is primarily (roughly 95%) made up of igneous rock and metamorphic rock. The remaining 5% is made up of sedimentary rock

Types of Crust

Earth’s crust is divided into two types:

Continental Crust

•      Continental crust is mostly composed of different types of granites.

•      Geologists often refer to the rocks of the continental

  Crust as “sial.” Sial stands for silicate and aluminum,

  The most abundant minerals in continental crust.

•      Its density is 2.7 grams per cubic centimeter.

Oceanic Crust

•      Oceanic crust, extending 5-10 kilometers beneath

•      the ocean floor

•      It is mostly composed of different types of basalts.

•       Geologists often refer to the rocks of the

     Oceanic crust as “sima.” It stands silicate and magnesium,

    The most abundant minerals in oceanic crust.

•       Oceanic crust is dense, almost 3 grams

     Per cubic centimeter

Mantle

•      The mantle is the mostly-solid bulk of Earth's interior.

•       The mantle lies between Earth's dense, super-heated core and its thin outer layer, the crust.

•       The mantle is about 2,900 kilometers thick, and makes up a 84% of Earth’s total volume.

Layers of Mantle

Upper Mantle

•      The upper mantle extends from the crust to a depth of about 410 kilometers. The upper mantle is mostly solid, but its more malleable regions contribute to tectonic activity.

Lower Mantle

•      The lower mantle extends from about 660 kilometers to about 2,700 kilometers beneath Earth’s surface. The lower mantle is hotter and denser than the upper mantle and transition zone

Core

•      Earth’s core is the very hot, very dense center of our planet.

•      It lies beneath the cool, brittle crust and the mostly-solid mantle.

•      The core is found about 2,900 km below

    Earth’s surface, and has a

    Radius of 3,485 km.

•      Unlike the mineral-rich crust and mantle,

   The core is made almost entirely of

    Metal—specifically, iron and nickel

Outer Core

The outer core, about 2,200 kilometers thick, is mostly composed of liquid iron and nickel. The NiFe alloy of the outer core is very hot, between 4,500° and 5,500° Celsius. The liquid metal of the outer core has very low viscosity, meaning it is easily deformed and malleable. It is the site of violent convection.

  Inner Core

•      The inner core is a hot, dense ball of (mostly) iron. It has a radius of about 1,220 kilometers. Temperature in the inner core is about 5,200° Celsius. The pressure is nearly 3.6 million atmosphere (atm).