EARTH LAYERS TO SCALE

The image below is a photo of the exhibit poster. A text transcript follows.

Photo of the poster from the exhibit.

Poster from Science Kit & Boreal Laboratories

This poster shows the scaled depth of the Earth's layers and atmosphere.
Scale: 1 millimeter (mm) = 1 kilometer (km)
Total depth from the center of the Earth to the highest mountain peak: ~6381 km

Transcription of poster from Outside Earth to Inside:

ATMOSPHERE
Distance from Earth's surface to top (no true boundary between atmosphere and space): ~ 480 km

  • Ionosphere
    Temperature: ~ -63 C (at 100 km altitude)*
    Thickness: ~ 400 to 1000 km**
    * Ionosphere cannot be defined by temperature difference. Nothing marks the end of the ionosphere and the beginning of space.
    ** Ionosphere thickness varies with day and night, with seasons, and with latitude.
  • Mesosphere
    Temperature: ~ -93 C (at 80 km altitude)*
    Thickness: ~ 30 km
    * Mesosphere is the coldest layer.
  • Stratosphere
    Temperature: ~ 0 C (at 47 km, almost at boundary)*
    Thickness: ~ 38 km
    * Stratosphere heats with altitude because it is warmed by ozone absorbing ultraviolet radiation.
  • Troposphere
    Temperature: ~ 15 to -58 C (as altitude increases)*
    Thickness: ~ 12 km
    * Troposphere cools with increase in altitude because some ultraviolet energy is absorbed at the Earth's surface, and the rest is emitted back out to the atmosphere as infrared energy. Additionally, the Earth's surface emits heat by conduction and convection.
  • Mount Everest 8.85 km high
  • Mariana Trench 11 km deep

CRUST 31.15 km thick on average
Temperature: ~ 15 C (average on surface)
Composition: Silicates*; Oceanic -- basalts* mafic rock (magnesium and iron);
     Continental -- granitic rock** sialic rocks (aluminum silicates)
Thickness: Oceanic: ~ 5 km; Continental: ~30-40 km
The Crust floats on the Mantle because the Crust is less dense.
* Basalt forms when molten materials harden.
** Granite also forms when molten materials harden.

  • Thickest part of the crust: 40 km thick
  • Thinnest part of the crust: 5 km thick

MANTLE ~2900 km thick
Temperature: ~ 1000 C
Composition: Solid* (mostly) Magnesium & Iron Silicates**
The Crust floats on the Mantle because the Crust is less dense.
* The upper mantle is made of rocks that flow when subjected to long periods of stress.
The upper mantle and crust together form a rigid layer of rock called the Lithosphere, which is 0-100 km thick.
The Lithosphere has broken into plates that float on the Asthenosphere. The Asthenosphere is 100-700 km deep.
** Silicates are a combination of Silicon, Oxygen, and other elements.

OUTER CORE ~2250 km thick
Temperature: ~ 3600 C
Composition: Liquid Iron* & Nickel (other materials to lower density)
* Movement of liquid iron makes a dipole magnetic field -- this is known as the "dynamo" theory.

INNER CORE ~1200 km thick
Temperature: ~ 4200 C
Composition: Solid Iron & Nickel