Warm-up

What are the phases of the moon starting with the New Moon?

Draw them.

Vocabulary Words• Asthenosphere-plasticlike layer of Earth on which the lithospheric plates float and

move around • Continental drift- Wegener’s hypothesis that all continents were once connected in

a single large landmass that broke apart about 200 million years ago and drifted slowly to their current positions

• Convection current- current in Earth’s Mantle that transfers heat in Earth’s interior and is the driving force for plate tectonics

• Lithosphere- rigid layer of Earth about 100 km, made of the crust and part of the upper mantle

• Pangaea- large ancient landmass that was composed of all the continents joined together

• Plate- a large section of Earth’s oceanic or continental crust and rigid upper mantle that moves around the asthenosphere

• Plate tectonics- theory that Earth’s crust and upper mantle are broken into plates that float and move around the plasticlike layer of the mantle

• Seafloor spreading- Jess’s theory that new seafloor is formed when magma is forced upward toward the surface at mid-ocean ridge

• Convergent boundary- when plates collide with each other• Transform boundary- when plates slide pass each other• Divergent boundary- plates are moving apart

Cornell NotesTitle: Plate Tectonics

• Standards: S6E5. Students will investigate the scientific view of how the earth’s surface is formed.

e. Recognize that lithospheric plates constantly move and cause major geological events on the earth’s surface.

f. Explain the effects of physical processes (plate tectonics, erosion, deposition, volcanic eruption, gravity) on geological features including oceans (composition, currents, and tides).

EQ: What is plate tectonics?

The Theory of Plate Tectonics

Plate Tectonics• The Earth’s lithosphere is divided into

plates that move on top of the asthenosphere.

Earth’s Major Plates

When the water moves beneath the raft, the raft moves with it. When the asthenosphere moves, the lithosphere moves with it…

Asthenosphere

Lithosphere

Types of Plate Boundaries

• When two plates meet, they form a boundary.

• There are three types of boundaries1. Convergent

2. Divergent

3. Transform

Convergent Boundaries

• Two plates push together

• Term to know: SUBDUCTIONSUBDUCTION means the crust is SINKINGSINKING!!

• Three types of convergent boundaries:1. Oceanic/Oceanic = subduction = TRENCH2. Oceanic/Continental = TRENCH3. Continental/Continental = MOUNTAINS

**Oceanic crust sinks, **Oceanic crust sinks, **Continental crust rises!!**Continental crust rises!!

Convergent Collision #1 Convergent Collision #1 (Oceanic/Oceanic)(Oceanic/Oceanic)

Both oceanic plates SINK (subduction!)(subduction!) and form a TRENCH. Magma rises and forms and island arc of volcanoes.

Subduction Zone

Convergent Collision #2 (Oceanic/Continental)

• The oceanic plate sinks (subduction!) below the continent and the continental plate slides over the top of the oceanic plate. Forms a TRENCH.

Subduction Zone

Convergent Collision #3(Continental/Continental)

• Both continental plates collide and rise up forming MOUNTAINS. (Ex. Himilayas)

Divergent Boundaries

• Two plates pull apart causing a rift valley in the middle.

• Sea-floor spreading is created by a divergent boundary.

Rift Valley

Mid Ocean Ridge

Sea Floor Spreading

• Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins

• Magma rises to the surface and solidifies and new crust forms

• Older Crust is pushed

farther away from the ridge

Transform BoundariesTransform Boundaries

• Plates slide past each other (Ex. Plates slide past each other (Ex. San Andreas Fault)San Andreas Fault)

• Causes earthquakes!Causes earthquakes!

San Andreas FaultThis fence used to line up!!

WHY do the plates move?…CONVECTION CURRENTS in the

mantle…Hot rock (less dense) rises to the surface, cools (more dense), and sinks back to the mantle.

HOT ROCK RISES

COOL ROCK SINKS

Convection Currents

Brain Pop!