Standard S 6.1 Students know evidence from plate tectonics is
derived from the fit of the continents and mid ocean ridges. S 6.1
Students know evidence from plate tectonics is derived from the fit
of the continents and mid ocean ridges.
Anticipatory Set Close your eyes Close your eyes Deep in the
ocean, the temperatures are freezing Deep in the ocean, the
temperatures are freezing No light No light There are bizarre
creatures living down there There are bizarre creatures living down
there Giant, red tipped tube worms, giants clams, and spider like
crabs Giant, red tipped tube worms, giants clams, and spider like
crabs This is what the bottom of the ocean looks like This is what
the bottom of the ocean looks like
Slide 6
Sonar is what scientist use in the mid-1900s to map the
mid-ocean ridge. Sonar is what scientist use in the mid-1900s to
map the mid-ocean ridge. Mid ocean ridges are found in all of
Earths oceans. Mid ocean ridges are found in all of Earths
oceans.
Slide 7
Mid ocean ridges curve like the seam of baseball on the ocean
floor. The mountains in this system lie hidden under hundreds of
meters or water. Mid ocean ridges curve like the seam of baseball
on the ocean floor. The mountains in this system lie hidden under
hundreds of meters or water. In a few places the ridge will poke
above the surface In a few places the ridge will poke above the
surface
Slide 8
Sea Floor Spreading Scientists in a submersible saw rocks
formed by the rapid hardening of molten material when they observed
mid-ocean ridges. Scientists in a submersible saw rocks formed by
the rapid hardening of molten material when they observed mid-ocean
ridges. In Sea-floor spreading, molten material rises from the
mantle and erupts along the mid-ocean ridges. In Sea-floor
spreading, molten material rises from the mantle and erupts along
the mid-ocean ridges. The sea floor spreads apart along both sides
of the ocean ridge as new crust is added. The sea floor spreads
apart along both sides of the ocean ridge as new crust is added.
The ocean floor moves like a conveyor belt, carrying the continents
along with them. The ocean floor moves like a conveyor belt,
carrying the continents along with them.
Slide 9
It forms a crack in the oceanic crust It forms a crack in the
oceanic crust Molten materials rises and erupts from the crack
Molten materials rises and erupts from the crack It moves over the
old crust It moves over the old crust Then begins to cool Then
begins to cool It then forms a new strip of rock It then forms a
new strip of rock
Slide 10
Evidence of Sea Floor Spreading Evidence: Evidence: Eruptions
of molten material- Eruptions of molten material- Alvin- small
submarine (withstand crushing forces) and the crew found rocks
shaped liked pillows Alvin- small submarine (withstand crushing
forces) and the crew found rocks shaped liked pillows Magnetic
stripes in the rock of the ocean floor Magnetic stripes in the rock
of the ocean floor Patterns in the rocks, contains iron, creates a
magnetic strip Patterns in the rocks, contains iron, creates a
magnetic strip The ages of the rocks The ages of the rocks Drilling
samples, brought up through pipes Drilling samples, brought up
through pipes Scientists discovered that rocks farther away from
the mid- ocean ridge were older than those near it by determining
the age of rock samples obtained by drilling on the sea floor.
Scientists discovered that rocks farther away from the mid- ocean
ridge were older than those near it by determining the age of rock
samples obtained by drilling on the sea floor.
Slide 11
Subduction at Trenches Part of the ocean floor sinks back into
the mantle at deep ocean trenches Part of the ocean floor sinks
back into the mantle at deep ocean trenches Subduction Subduction
New ocean floor is hot New ocean floor is hot Moves away and cools
and becomes dense Moves away and cools and becomes dense Gravity
pulls the older floor beneath the trench Gravity pulls the older
floor beneath the trench
Slide 12
Together Together they have changed the size and shape of our
oceans Together they have changed the size and shape of our oceans
The Pacific Ocean is shrinking, how can that be? The Pacific Ocean
is shrinking, how can that be? The trenches around the edges are
pulling in the older crust. The trenches around the edges are
pulling in the older crust.
Slide 13
Checking for Understanding ___________________is what scientist
use in the mid-1900s to map the mid-ocean ridge.
___________________is what scientist use in the mid-1900s to map
the mid-ocean ridge. ____________ ______________ _______________are
found in all of Earths oceans ____________ ______________
_______________are found in all of Earths oceans What is
subduction? What is subduction?
Slide 14
Guided Practice Independent Practice Guided Practice Building
Vocabulary Guided Practice Building Vocabulary Stop!!! See Me!!!
Stop!!! See Me!!! Independent Practice: Side one #1-5 Independent
Practice: Side one #1-5 Back side: Homework! Back side:
Homework!