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
