Science: Layers of the Earth

Crust

where we live - thinner outermost layer- 35 km

oceanic crust

made up of silica magnesium basalt- young

continental crust

made up of copas and granite- old

AAndrija Mohorovicic

Geophysicist from croatia - found the velocity of seismic waves

Mohorovicic Discontinuity or Moho

interface between crust and mantle

Mantle

found beneath the crust - 2900 km - thickestlayer- made up of SIMO

Beno Gutenberg

german seismologist- observed P waves

Shadow Zone

about 35. wide- a belt where direct P waves are absent

Gutenberg Discontinuity

marks the bondary between mantle and outer core

Core

beneath the mantle- innermost layer- composed of irn alloy and nickel

Outer Core

liquid layer - 2270 km - zone that generates earth’s magnetic field

Inner Core

solid layer - materials stronger than the outer coere

Inge Lehmann

danish seismologist - discovered the solid inner core inside the molten outer core

Lehmann Discontinuity

Interface between the liquid outer core and the solid inner core

Lithosphere

divided into separate plates which move very slowly in response

Asthenosphere

soft layer of mantle

Core

greatest temperature and density

Seismic Waves

waves of energy caused by the sudden breaking of the rock

Body Wave ( P wave)

first kind of body wave is the P wave. fastest kind of seismic wave. can move through solid rocks and fluid

S wave

S wave is slower than P wave. can only move through solid

Love Waves

first kind of surface wave. named after Augustus Edward Hough love. Fastest Surface Wave

Rayleigh Wave

rolls along the ground