Earth's Crust is broken...but the pieces fit together like a puzzle! And they move- constantly!! What theory explains this process? Were there other theories before this one was determined to be the most well supported? Plate Tectonics
270 million Pangaea What do we call the large land mass that all continents created 270 million years ago? How could that have happened? Are the continents still moving today? Pangaea
Earth's Crust is broken into Tectonic Plates. Some plates carry continents. Some plates are mainly under the ocean.
Identify the 3 ways that plates can move. What do we call the boundaries that these plates form?
What do we call the movement of heat in the Mantle that causes the plates to move? Convection Currents create the force that makes the plates move.
What can cause this shaking and trembling of the solid Earth? What do we call this "crack" in the Earth's Crust?
What is this instrument? What is it used for? What is this recorded data called?
Mostly unnoticeable Felt by all- little damage When Seismologists give an Earthquake a "number" to describe how powerful the earthquake is, we call that the Earthquake's. Magnitude Moment Magnitude Scale
Where do most earthquakes occur?
Big Ideas: 1. Where do most volcanoes occur? 2. What are the forces that cause a volcano? Pressure 3. How can volcanoes occur in the middle of tectonic plates?
Volcanoes form when there is a weak spot on the Earth's crust and magma forces its way to the surface! - convergent boundaries (especially subduction zones) - divergent boundaries (sea floor spreading under the oceans) - hot spots
Older Crust has moved past the Hot Spot Younger Newer What does this diagram represent?
Demonstrations: Raw egg- what is the energy that is creating a force making pressure build? Why does the "magma" flow out of the cracks? Earth with no cracksadd heat and pressure Earth with a crack- add heat and pressure.
Identify the parts of the volcano that this model represents: Pipe Vent Magma Magma Chamber Side Vents
Type of lava: viscous lava Lava-
Shapes of Volcano: Shield volcano: Toothpaste tubes Demo; 1 per table; compare tubes with no cracks to tubes with cracks(vents); Quiet Eruptions: lava flows easily and there are multiple vents to release pressure. Composite Volcanoes can be quiet or explosive:balloon- DEMO-1. quiet 2. explosive Gas: When heated it expands; can create an explosive eruption. Demo: 2 liter club soda bottles-compare no crack/crack- type of eruption? Caution! Limit touching lava!
Match the name with the volcanic shape: Composite Cinder Cone Shield
Might Like the club soda bottle
destruction (duration) Explosiveness, destruction and how long it erupts- in seconds.
How does the Earth's solid crust change? 1. Plates moving apart (divergent boundaries) can mountains under the ocean (sea floor spreading)
Earth Changes!! 2. Some changes are slow (erosion by wind, water, ice) 3. and 4. Some changes are fast- earthquakes http://sciencenetlinks.com/interactives/shapeitup.html
3. EARTHQUAKES CAN CHANGE THE SURFACE OF THE EARTH! past (transform) can create Earthquakes! Draw epicenter What are the two scales used to measure the magnitude of an Earthquake?
4. VOLCANOES CAN CHANGE THE EARTH'S Convergent boundaries- subduction zones- can create mountains, trenches, volcanoes, earthquakes Divergent boundaries- under the oceans- can create new crust, mountains and trenches (Sea Floor Spreading) in the mantle can cause mountains to form... Island building. Types of volcanoes: Draw a volcano and see if class can identify it and its parts.
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(Identify: magma chamber, pipe, vent, crater) What type of eruption? Where would you find Click to reveal
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What are the variables that lead to the most explosive volcanic eruptions? What effect does gas have?
Natural Phenomena: and other Earth (15 minutes)