Plate Tectonics Goal: Homework: Warm-up: Locate different types of plate boundaries on the sea floor map. DR 4.3 “Plate Tectonics” due tomorrow In your science journal  Look at the diagram on p. 108 – 109. What happens when a continental plate and oceanic plate collide? What is this process called, and why does it happen?

Plate Boundaries To view this animation, click “View” and then “Slide Show” on the top navigation bar. Animation

Geology Articles

Plate Boundary Diagrams On the back of your map: Transform Boundary Divergent Boundary Convergent Boundary (oceanic/continental) Convergent Boundary (oceanic/oceanic) Convergent Boundary (continental/continental)

Tectonic Plates

Mid-Ocean Ridges

Deep-Sea Trenches

Plate Boundaries Goal: Homework: Warm-up: Draw diagrams for each of the types of plate boundaries. none In your science journal  After watching BrainPop, list and describe each of the three types of plate boundaries. Tell what features you’d expect to find at each type.

Seafloor Map

Plate Boundaries Divergent Convergent Transform

Plate Boundaries To view this animation, click “View” and then “Slide Show” on the top navigation bar. Animation

So why is it called the “Theory” of Plate Tectonics? Lithosphere is broken up into many plates Interaction between the plates causes continents to move and oceans to expand Earthquakes, volcanoes, and other plate movement all caused by heat trying to escape from the Earth’s interior. So why is it called the “Theory” of Plate Tectonics?

What happens at a divergent boundary? Mid-Atlantic Ridge Plates moving apart Seafloor spreading Mid-ocean ridge Volcanic activity

How does a new ocean form? Magma in the ________________ starts to push through and form a new ______. asthenosphere rift

The Great Rift Valley ___________boundary on a continent New _______ forming Divergent ocean Label the Great Rift Valley on your seafloor map. Click here to see what’s happening at this rift valley.

Plate Tectonics In your science journal  Goal: Homework: Warm-up: To draw diagrams of each type of plate boundary. none In your science journal  Look at this diagram of a convergent boundary between two oceanic plates. What causes the trench to form, and what causes the island arc to form?

What happens at a transform boundary? All these “strike-slip” faults surrounding the ridge are called the “fracture zone”. Plates move laterally past each other Many earthquakes

San Andreas Fault

Seafloor Map Also, label the large transform boundary that cuts across the East Pacific Rise. Label the San Andreas Fault on your seafloor map.

What happens at a convergent boundary? Plate are pushed together Depends on which types of plates are converging

(oceanic/continental) Convergent (oceanic/continental) Oceanic goes under continental due to greater density Trench is created off the coast Mountains created on land due to rising magma magma

The Andes Mountains

Convergent (oceanic/oceanic) The OLDER oceanic plate will sink beneath the other Trench is created in between the plates An island arc is created due to rising magma magma

Island Arcs Japan Aleutian Islands, Alaska The Philippines

(continental/continental) Convergent (continental/continental) Both plates collide and deform The crust thickens as mountains are pushed upward Regional metamorphism takes place

The Himalayas

For a closer look at anywhere in the world click the map below:

Volcanic activity at plate boundaries To view this animation, click “View” and then “Slide Show” on the top navigation bar. Animation

Plate Boundaries To view this animation, click “View” and then “Slide Show” on the top navigation bar. Animation

Convection and Tectonics What causes the plates to move? Convection and Tectonics To view this animation, click “View” and then “Slide Show” on the top navigation bar. Animation

CLICK ME! Convection circulation Hottest magma  RISES Cooler magma  These motions cause _____________ RISES SINKS circulation

How is a lava lamp like the mantle? To view this animation, click “View” and then “Slide Show” on the top navigation bar. Animation

Plate Boundary Diagrams On the back of your map: Transform Boundary Divergent Boundary Convergent Boundary (oceanic/continental) Convergent Boundary (oceanic/oceanic) Convergent Boundary (continental/continental)

Convergent Boundary Goal: Homework: Warm-up: To complete and label the features on a profile of the seafloor. Study for plate tectonics quiz tomorrow In your science journal  Without looking at your book, notes, or map, draw and label a diagram showing a convergent boundary between continental and oceanic plates. You have 60 seconds starting…

Convergent Boundary Goal: Homework: Warm-up: To complete and label the features on a profile of the seafloor. Study for plate tectonics quiz tomorrow In your science journal  Without looking at your book, notes, or map, draw and label a diagram showing a convergent boundary between continental and oceanic plates. You have 60 seconds starting… NOW!

(continental/oceanic) Convergent Boundary (continental/oceanic)

How many different plates are there in this diagram? Subduction Zones How many different plates are there in this diagram? 1 2 3 4

Label the features below: Subduction Zones Label the features below:

Subduction Zones sea floor spreading subduction oceanic Identify the plate boundaries by placing a big letter “D” above the divergent boundary and placing a “C” above each convergent boundary. What process is taking place along the ridge? What process is taking place at the trenches? During subduction, a(n) ___________ plate will sink beneath the continental plate. 4. What causes one plate to sink while another floats? sea floor spreading subduction oceanic Oceanic crust is denser than continental because it’s more mafic in composition.

Subduction Zones (continued) Using a green colored pencil, shade in the area where the youngest ocean rocks would be found. Then, in blue, shade in the area of oldest ocean rock. Which of these areas (green or blue) would have the thickest sediment sitting on top of it, AND why? Using a red colored pencil, color in 2 areas where you would find melting rock. What happens to the melted rock, and what landforms does it produce? Blue would have the thickest layers of sediment because it’s older and has had more time to accumulate debris. The melted rock (magma) rises to the surface because it’s hot (less dense) where it creates volcanoes.

Subduction Zones (continued) On your diagram, draw circular arrows like those in Figure 1 on p. 110 to show the circulation of the magma within the Earth. What is the name of this process? 8. Plate tectonic motion is causing the ___________ Ocean to expand, while the __________ Ocean is getting smaller. convection Atlantic Pacific

Advanced Article Assignments Online Quiz: Quiz window: Thurs. 10/29 through Mon. 11/2 at 11:59 pm. Everyone takes both quizzes. See my website for the links. Article Summary: Due Wed. 11/4 (day after ½ day) Choose ONE article of the two for the Geology Unit. Everyone EXCEPT presenters PowerPoint Presentation: Wed. 11/4 Look at rubric for requirements Only our two presenting groups (see me after class)