Transcript File

Earth’s Interior
and How It Affects the Earth’s Exterior
Earth’s Spheres
Atmosphere (air)
Biosphere (life)
Hydrosphere (water)
Geosphere (rock)
Parts of the Geosphere
Inner Core

solid
Outer Core

Liquid (molten rock)
Mantle

solid
Asthenospere

Hot, soft rock that flows
like tar. Crustal plates
float on this
Crust (lithosphere)

7km-70km deep
Our Dynamic Planet
Dynamic—powerful or active or
ever-changing
(from a report by J.-P. Bardet at USC and others at Gifu Univ.; used by
permission; and from Japanese TV)
Eruption of Etna
volcano at dusk.
Copyright 2002
by Ben Kennedy
www.peakbagger.com
What Other Ways Has the
Earth Possibly Changed?
Pangaea
(one massive
piece of land)
Present-Day
How Did Scientists Come Up
With ‘Pangaea’?
Continental Drift
Theory (same as
plate tectonics)


Alfred Wegener
Apparent fit of South
America and Africa
Evidence



Fossils
Plants
Landforms
Why do the plates move?
Convection





Occurs in the mantle
Part of mantle close to outer core are
heated.
Those parts expands, makings it less dense
(mass/volume).
Less dense parts rise until it cools off again
Continuous cycle (p. 24)
Convection Creates:
mid-oceanic ridges



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Continuous mountain range in all oceans
Rise due to the hot rock (mantle) rising
under the cool sea water
Causes sea floor to expand
New crust created during sea-floor
spreading; made of basalt