layers of the earth

• layer of the earth

  A) lithosphere

  B) asthenosphere

  C) crust

  D) mantle

  E) core

  F) mesosphere

  G) outer core

  H) inner core

  
• The Earth can be subdivided into layers based on two criteria: (1) composition (density) differences and (2) physical properties.
• (2) type of layer

  1. compositional 2. mechanical
• (3) primary compositional layer

  1. crust
  2. mantle
  3. core
• crust- thinnest and outermost layer of the Earth.
• (2) types of crust

  * continental crust- thicker but less dense, older and more buoyant type of crust.

  * oceanic crust- thinner but denser, younger and denser type of crust.
• mantle- comprises most of the Earth’s volume (more than 80%) and begins where the crust ends.
• Mohorovičić discontinuity- The boundary between the crust and mantle

  *It can be divided into the upper and lower mantle, separated by the Repetti discontinuity.
• core- the center of the earth, Inner layer. consist of two part: outer- extreme high temperature, inner- so much pressure
• (4) mechanical layer

  1. lithosphere
  2. asthenosphere
  3. mesosphere
  4. outer & inner core
• lithosphere-  thick and brittle layer comprising the entire crust and uppermost layer of the upper mantle.
• asthenosphere- is a mechanically weak layer consisting of the lower portion of the upper mantle, top portion
• mesosphere- (from the Greek word mesos meaning “middle”), comprised of the lower mantle. Level of pressure starting to build up.

  *The dominant rock type in this layer is a silicate rock called perovskite.
• outer core- liquid iron and nickel, only made out of liquid–melted Fe-Ni alloy, to be exact.
• inner core- solid iron and nickel, solid ball of mostly Fe.