1. Monday February 13, 2012
• Question of the Day #93 on page 55
• Return folders & explain how they were
graded
• Review and finish foldable
• Convection currents animations
• Earthquakes & Volcanoes worksheet

2. Green Folders
• Complete Table of Contents 1 point
• Complete Vocab List (page 4) 1 point
• Page 188 questions 1-6 (page 23) 6 points
• “Is the Earth preparing to flip?” (page 25) 1 point
• Magnetic reversals graphing (page 26) 1 point
FOLDER TOTAL 10 POINTS
• We also recorded the score for the “Earth’s Layers Online Activity”
(page 19). This was a 24 point assignment, so if you misplaced
it, that’s a big hole in your grade! Find this and get it to me! There
are extra copies up front, or you can follow the link on my website
in my post from Tuesday 1/31/12 and answer on a separate sheet
of paper.

3. Foldable
Make 3 Cuts –
DON’T CUT ALL THE
WAY ACROSS

4. Foldable
PLATE
TECTONICS
THEORY
Foldable – Front View
CONTINENTAL
DRIFT THEORY
SEA FLOOR
SPREADING
CONVECTION
CURRENTS

5. Plate Tectonics Theory
• Plate – a large slab of solid rock
• Tectonic – to build
• This theory state that the crust is broken into
large pieces (plates) and those plates move
atop a hotter molten layer (mantle)

6. Foldable
PLATE
TECTONICS
THEORY
Foldable – Front View
CONTINENTAL
DRIFT THEORY
SEA FLOOR
SPREADING
CONVECTION
CURRENTS

7. Continental Drift Theory
• Developed by Alfred Wegener
• Continents had once been joined together in
one land mass called Pangaea, but they had
since drifted apart
• Initially met with hostility and skepticism.
Scientists couldn’t believe that whole
continents had moved. Wegener was a
meteorologist, not a geologist – what could
he know about the Earth?

8. Foldable
PLATE
TECTONICS
THEORY
Foldable – Front View
CONTINENTAL
DRIFT THEORY
SEA FLOOR
SPREADING
CONVECTION
CURRENTS

9. Sea Floor Spreading
• Developed by Harry Hess.
• Sea floor is created by cooling lava rising
through a mid-ocean ridge.
• As new lava comes up, older rock sea floor is
moved aside.
• Youngest rocks nearest the ridge; oldest
farthest away.
• Magnetic reversals provide evidence.

10. Foldable
PLATE
TECTONICS
THEORY
Foldable – Front View
CONTINENTAL
DRIFT THEORY
SEA FLOOR
SPREADING
CONVECTION
CURRENTS

11. Convection Currents
• Hot, less dense rock is forced to rise upward
through cooler, denser rock
• As the hot material rises and reaches the top
of the mantle, it cools and sinks back down
• When it reaches the bottom, it heats back up
and rises again, repeating the cycle again and
again and again.
• This is thought to be the driving force behind
plate tectonics.

12. Convection Current Animations
• Animation #1
• Animation #2

13. Today’s Assignment
(Homework if you don’t finish in class!)
• Fast Changes to the Earth’s Surface worksheet
• Read the information on the front and use it
to answer the questions on the back. This will
be good background info for our activity
tomorrow.
• We’ll be interpreting data about earthquakes
and volcanoes and trying to find meaningful
patterns related to plate boundaries.