STRUCTURE OF THE EARTH - created from Mind Map

Seite 1

CRUST

MANTLE

CORE

Discontinuities

OCEANIC CRUST

CONTINENTAL CRUST

Makes up 1% of mass and 2% of volume of earth and have depth of 0 to 35km

Rich in oxygen, silicon and aluminium, and lesser amounts of other elements

Feldspar, which is plagioclase and orthoclase is the most abundant mineral followed by quartz and hydrous minerals

3 - 10km thickness

3.0 gcm³ average density

2.7 gcm³ density

Pressure increases with depth at a rate of about 30MPa km−1, and temperature increase at an average rate of around 25 °C km-1

Upper crust 0 km to 12 km Middle crust 12 km to 23 km Lower crust 23 km to 40 km

UPPER MANTLE

Made up of silicates

Have depth of 35km to 2890km

Temperature varies from 1000°C to 3700°C near the core

Transition zone

Lower mantle is less ductile than upper mantle and transition zone

D''

Have density of 3.4 to 4.4 g/cm^3

Have depth of 35km to 60km

Also contains other elements such as iron, aluminium and calcium

Heat and pressure increase with depth

Rocks change their crystalline structure, becoming denser

Lies around 410km to 660km beneath surface

Area between lower mantle and outer core (around 200km)

May contain iron and silicates

OUTER CORE

INNER CORE

Mainly made up of iron and nickel

Liquid

Density of 9.9 to 12.2 g/cm^3

Depth of 2890km to 5100km

Maintains the magnetic field of the Earth

Temperature around 4500°C to 5500° C

Depth of 5100km to 6378km

Density of 12.8 to 13.1 g/cm^3

Solid

Temperature around 5200° C

Pressure nearly 3.6 million atm

MOHOROVIČIĆ

GUTENBERG

LEHMANN

By Andrija Mohorovičić (1857 – 1936)

Crust - mantle boundary

By Beno Gutenberg (1889–1960)

Mantle - core boundary

P wave reduced, S wave disappear

By Inge Lehmann (1888-1993)

Outer core - inner core boundary

Occurence of shadow zone is seismic velocity