The Restless Earth

1
The Restless Earth

• Nicole Duval
• Hon 251
• March 1, 2006

2
Earth is always changing

• Inside earth
• Radio active elements are decaying
• Energy converted to heat
• Heat moves to surface
• Rise, cool, sink warm, rise, cool, sink warm

3
Only planet still being born

• Continents float, collide, tear apart, and link
  together again.
• Ocean basins open and close
• Mountains thrown up and weathered down
• Rocks move about 1 inch a year

4
Heat

• Drives the motion of the mantle
• Comes from
• Radio active decay
• Heat left over from the formation of the earth

5
Plate Tectonics

• Plates
• Thin brittle slabs of crust
• 4/5 of the earth
• Plate boundaries
• Divergent
• Convergent
• Neutral

6
Continents Plates????

• Nope!
• 6 continents, at least 12 plates
• If only 1 plate carries continent crumbles at
  region of contact
• If 2 plates continents crash and form high
  mountains

7
More fun with these plates

• Evidence measurements of rock magnetism on ocean
  floor
• Extragalactic astronomy-measurements of the
  radiation from distant quasars
• YAY New England for having the only quasar
  observatory

8
Why is it important

• Its not! Just kidding! It might be if you get
  into this kind of stuff
• Common language
• Common ground for all scientists studying the
  earth
• Know the whys behind
• Earthquakes
• Volcanoes
• Ore deposits
• Rocks and fossils matching across oceans

9
No mountains on mars? What about us northern
hikers?

• Way too small
• Heat generated in the interior flows to surface
  and is radiated away
• No plates, no collisions

10
Seismology

• Measuring sound on a global level
• Helps understand earths layers
• Core
• Mantle
• Crust
• Can deduce location and force of earthquakes

11
Gas prices and plates

• If we know where the plates are we can get
  untapped natural resourcesBush what are you
  doing over in Iraq?
• Fossil fuel search expanded

12
Some people devout their lives to understanding
the earthcan you imagine?!

• Mineral physicists
• Supercomputers
• Discovered earths poles have not always been
  where they are.
• One day it could be opposite

13
The moon

• Differentiation accumulated heat from collisions
  raised earths temp, rocks melted, heavy materials
  melted to center
• Big Splash after differentiation, one meteorite
  crashed into earth, threw mantle material into
  space, moon formed from this material