Physical Science

Interior of the Earth

Earthquake And Volcano Map

Earthquake Information

http://www.earthquake.gov/eqcenter/

http://www.earthquake.gov/eqcenter/

http://earthobservatory.nasa.gov/NaturalHazards/category.php?cat_id=12

We understand the components of our earth by looking at Seismic wave – waves traveling

through the earth

From Yahoo Images

Seismic Waves

• Body Waves – travel through the earths interior• Surface Waves – travel on the earths surface

From Yahoo Images

Body Waves

Primary waves (p wave) longitudinal type waves

travel in all directions from source

move faster than s waves

Secondary waves (s wave) Transverse type wave

Similar to waves produced from a violin string

Cannot propagate through liquid

Surface wave

• Rayleigh waves – move in an

up and down motion

• Love waves – move in a side

to side motion

S Waves

Do Not Travel Through Liquids

From Yahoo Images

Waves Through the Earth

Waves Through the Earth

The core

• Inner core – composed of Iron and nickel solid

• Outer core – liquid iron and nickel – the flow of these metals produces the magnetic

field

From Yahoo Images

The mantle

Composed of hot iron rich silicate rocks

Upper mantle

• Asthenoshphere – lower portion plastic like properties

• Lithosphere – floats on the asthenoshpere and

includes the crust

Continental crust is less dense than ocean crust – floats

Continental drift

Pangaea – having all the continents together as on land mass

Evidences for such a theory

• Mountain chain similarities

• Identical rock compositions

• Similar fossil findings

• Climatic data – ice sheets

• Change of the earths magnetism