Transcript Divergent Boundary

• Take out a sheet of paper and set it up as shown
below. Use the whole sheet of paper.
Divergent
Type of
Movement
Sketch of
boundary
Landforms
created
Convergent Transform
Today’s Schedule
• 1. Schedule for the week.
• 2. Continue with Ch. 7 Section 3 Discussion
• 3. Begin work on Plate Tectonics WS
• land masses have slowly
moved over time
• Plates move on top of
asthenosphere
• Two plates slip past each
other in opposite directions
Matching Game
• Convergent boundary
• Sea-floor spreading
• Plate tectonics
• Happens at divergent
boundaries, allows magma to
rise to the ocean floor
• Continental drift
• Two plates collide with each
other
• Divergent boundary
• Two plates separate with
each other
• Transform boundary
Ch. 7 Section 3 The Theory of Plate
Tectonics
Things you should know: what plates are,
directions plates move, and some landforms
that plate movement creates.
Now, you need to figure out what causes the
plates to move.
Observe these demonstrations to discover
the answer.
Convection
• Convection- heat transfer by the movement of
currents within a fluid
• Caused by differences of temp. and density
within the fluid
Convection Currents in Earth
• 1. What is the heat source?
• 2. What is flowing?
• Heat from the core and the mantle itself causes
convection currents in the mantle.
•
Google Image Result for http://www.windows.ucar.edu/earth/interior/e_thermal_history_animated.gif
Plate Boundaries
• Divergent Boundary- place where 2 plates
move apart or diverge.
• Most DB’s are at mid-ocean ridges.
• On land DB’s form deep valleys called rift
valleys
•
Fig. 19.21 - Evolution of a Divergent Plate Boundary
Convergent Boundary
• Place where 2 plates come together, or
converge.
• Oceanic plate + Continental plate = subduction
• Continental plate + Continental plate =mountains
•
OptIPuter Outreach
Subduction at Trenches
• Deep-ocean trench- underwater canyon where
ocean crust sinks into the mantle.
• Subduction- process by which ocean crust
sinks beneath a deep-ocean trench and back
into the mantle
•
Subduction Animation - Earthguide Online Classroom
Transform Boundary
• Place where two plates slip past each other in
opposite directions.
• Transform Boundaries = Earthquakes
•
Observe animations of processes that occur along plate boundaries.
The Big Picture
• Sea-floor spreading and subduction change the
size and shape of the ocean floor.
• 200 million years for a rock to be “born” at a
mid-ocean ridge, move across the ocean floor,
and then sink into the mantle.
• The Pacific Ocean is sinking and The Atlantic
Ocean is growing.
Transform
Plate Boundaries Contest
Convergent
Divergent
Assignment
Points
Received
1. Signed Rules & Procedures
2. All About You
3. Brain Pop Sci. Meth. WS
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10
5
10
4. Observation vs. Inference Unit1
Section 2 Notes
5. Sci. Meth Quiz
6. Tootsie Pop Lab
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10
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10
7. Science Pre-Test
8. Earth’s Layers WS
9. Ch. 7 Section 1 Quiz
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10
10
15
10. Pangaea Lab or Ch. 7 Section 2
Review
11. Ch. 7 Section 2 & 3 Outline
Total Points
Possible
10
10