What are the layers of the Earth? What is one fact about each layer? 5 minute check October 7, 2013 What are the layers of the Earth? What is one fact about each layer? http://www.cnn.com/2012/10/01/tech/mantle-earth-drill- mission/index.html 3.1 - The student will describe the characteristics of the layers of the earth.

Listen to song- http://www.flocabulary.com/geology/

Let’s watch Bill Nye The science guy video Earth’s Crust While watching the video I want you to fill in the Earth’s Crust Quiz

Closing: What is “Pangaea” (whole earth)?

What is “Pangaea” (whole earth)? 5 minute check October 8, 2013 What is “Pangaea” (whole earth)? 3.1 - The student will describe the characteristics of the layers of the earth.

Evidence for Plate Tectonics Plate Tectonic Theory Evidence for Plate Tectonics

CONTINENTAL DRIFT Alfred Wegener in the early 1900’s proposed the hypothesis that continents were once joined together in a single large land mass or super continent he called Pangea (meaning “all land” in Greek). He proposed that Pangea had split apart and the continents had moved gradually to their present positions - a process that became known as continental drift.

CONTINENTAL DRIFT According to the hypothesis of continental drift, continents have moved slowly to their current locations.

Pangaea about 200 million years ago, before it began breaking up. Wegener named the southern portion of Pangaea Gondwana, and the northern portion Laurasia.

The continents about 70 million years ago The continents about 70 million years ago. Notice that the breakup of Pangea formed the Atlantic Ocean. India’s eventual collision with Eurasia would form the Himalayan Mountains.

The position of the continents today The position of the continents today. The continents are still slowly moving, at about the speed your fingernails grow. Satellite measurements have confirmed that every year the Atlantic Ocean gets a few inches wider!

Wegener’s Evidence for Continental Drift Continents fit together like a puzzle….e.g. the Atlantic coastlines of Africa and South America. The Best fit includes the continental shelves (the continental edges under water.) Picture from http://www.sci.csuhayward.edu/~lstrayer/geol2101/2101_Ch19_03.pdf

Wegener’s Evidence for Continental Drift Picture from http://volcano.und.edu/vwdocs/vwlessons/plate_tectonics/part3.html Fossils of plants and animals of the same species found on different continents.

This hypothesis helped to explain why fossils of plants and animals, along with matching rocks (strata), have been found on both sides of the Atlantic Ocean. Example: Applachain Mountains And if the continents are put back to their pre-drift locations the mountains form a continuous chain.

Lystrosaurus - fossils of this little land reptile were found in Africa, India, Argentina, China and Antarctica!

Wegener’s Evidence for Continental Drift Rock sequences (meaning he looked at the order of rock layers) in South America, Africa, India, Antarctica, and Australia show remarkable similarities. Wegener showed that the same three layers occur at each of these places. Picture from http://volcano.und.edu/vwdocs/vwlessons/plate_tectonics/part4.html

Seafloor Spreading Everyone agreed that Wegener’s evidence was compelling. But wouldn’t we feel the movement? Also, wouldn’t there be evidence to show that the continents were still moving today? Wegener was a meteorologist and his theory was not well accepted. (He died on an expedition in Greenland collecting ice samples)

Seafloor Spreading One reason scientists had a hard time with Wegener’s theory is that there was no mechanism for the continents motion.

Seafloor Spreading In the 1960’s, a scientist named Henry Hess made a discovery that would vindicate Wegner. Using new technology, radar, he discovered that the seafloor has both trenches and mid-ocean ridges. Harry Hess proposed the sea-floor spreading theory. Picture from USGS http://pubs.usgs.gov/gip/dynamic/HHH.html

Seafloor Spreading Hess proposed that hot, less dense material below Earth’s crust rises toward the surface at the mid- ocean ridges. Then, it flows sideways, carrying the seafloor away from the ridge in both directions. Picture from http://library.thinkquest.org/17457/platetectonics/4.php

Seafloor Spreading As the seafloor spreads apart at a mid- ocean ridge, new seafloor is created. The older seafloor moves away from the ridge in opposite directions. This helped explain how the crust could move—something that the continental drift hypothesis could not do. Picture from http://www.pbs.org/wgbh/aso/tryit/tectonics/divergent.html

Evidence for Spreading In 1968, scientists aboard the research ship Glomar Challenger began gathering information about the rocks on the seafloor. Scientists found that the youngest rocks are located at the mid-ocean ridges.

Mechanism for Plate Tectonics Seafloor Spreading provided insight to the mechanism for how the continents moved. The magma which pushes up at the mid-ocean ridge provides the new land pushing the plates, and the subduction zones gobble up the land on the the other side of the plates. Picture from http://library.thinkquest.org/17457/platetectonics/2.php The mechanism was convection currents!

Plate Tectonic Theory Both Hess’s discovery and Wegner’s continental drift theory combined into what scientists now call the Plate Tectonic Theory. Theory of plate tectonics: The Earth’s crust and part of the upper mantle are broken into sections, called plates which move on a plastic-like layer of the mantle

Plate Tectonic Theory Plate Tectonics explains Earthquakes Mountains Volcanoes

Closing: What is continental drift?

What is continental drift? 5 minute check October 9, 2013 What is continental drift? 3.1 - The student will describe the characteristics of the layers of the earth.

Let’s review from yesterday Alfred Wegener hypothesized what? Supercontinent called Pangaea What evidence did he use? Similarities in the types of rocks and ancient fossils In the 1960s scientists discovered what about the sea floor? Between the crust and the mantle there were all cracks and each piece they called plates. They called the moving of these plates Plate Tectonics. They are in constant motion and if there is a continent on the plate then it too is moving.

We are going to watch a video on sea floor spreading

So why do the plates move???? First thing we have to understand that in the Asthenosphere there are convection currents. But why do we have convection currents in the Asthenosphere??? Well the first thing we have to understand is that heat can travel three different ways YUP 3!!!! Example

So how do the plates move??? By convection! Let’s see an example of what convection is example we will need cold water and warm water Students have a try at it, example

See convection currents lab Fill the large beaker to EXACTLY 300ml, place in middle of draw In the small beaker fill close to the top, but not so high that you cannot walk while holding it Add EXACTLY 3 drops of food coloring to your SMALL beaker and stir with straw calmly till mixed Bring your small beaker to the microwave and heat water for 30 seconds. Using a paper towel to hold the small beaker walk calmly back to your group. Place a piece of tin foil TIGHTLY on your small beaker and drop it gently into the lager beaker carefully! Try not to spill! Using your straw poke A (meaning 1) hole in your aluminum foil to let small beaker water out into big beaker. Watch to see convection currents occur Clean and dry all materials before you return them to the counter

Closing What is convection heat?

What is convection heat? 5 minute check October 10, 2013 What is convection heat? 3.1 - The student will describe the characteristics of the layers of the earth.

Plates on the Move Now that we know why they move lets learn about the different movements plates can make

There are three types of plate movement

1. Divergent An example is seafloor spreading Plates are separating from each other as a new land mass forms This is seen at mid-ocean ridges and rifts Plate separation is a slow process. For example, divergence along the Mid Atlantic ridge causes the Atlantic Ocean to widen at only about 2 centimeters per year. Even though most are under the sea, not all of them are, when two continental crusts begins to separate the stretched crust forms a long, narrow depression called rift valley. A rift valley is currently forming in East Africa, and might eventually be new ocean basin.

2. Convergent Two continental plates collide. & crumple the edges of the plates & form mountains. We can see the end result of the collision between the Indian & Eurasian plates which are the Himalayan Mountains. Picture from USGS Picture from www.geology.com Author Hobart M. King

collision Three types of convergent boundaries: Continental-Continental Oceanic-Continental Oceanic-Oceanic destruction Produces a subduction zone, where the lithosphere is sliding back into the mantle.

What type of convergent boundaries are these? ______________ _______________ Continental-Oceanic Oceanic-Oceanic Continental-Continental

Subduction When an oceanic plate goes underneath or is subducted under a continental plate it is called subduction. This forms a trench, or deep valley, where the plates meet. An example of a subduction zone is the Marianas Trench where the Pacific Plate is subducting under the Eurasian Plate. Subduction is another type of a convergent plate movement. Picture from www.geology.com Author Hobart M. King

3. Transform Two plates slide past each other At transform boundaries crust is only deformed or fractured. Example: San Andreas Fault in California

Flip Book for our notebooks

A Divergent B Convergent C Transform plates are moving apart new crust is created Magma is coming to the surface plates are coming together crust is returning to the mantle plates are slipping past each other crust is not created or destroyed

A Divergent B Convergent C Transform Continental crust  rift valley Oceanic crust  mid-ocean ridge 2 continental plates  mountain range Plates move against each other Stress builds up Stress is released earthquake 2 oceanic plates or oceanic + continental subduction

Plate Tectonics Vocabulary Fault: a crack or fracture in the Earth’s crust along which movement, dislocation and overlaps of plates occur. Plate Boundary: Where two or more plates meet

Transform Convergent Divergent

Closing: What are the three main types of plate movements?

What are the three main types of plate movements? 5 minute check October 11, 2013 What are the three main types of plate movements? Video 3.1 - The student will describe the characteristics of the layers of the earth.

Friday Quiz

A Divergent B Convergent C Transform plates are moving apart new crust is created Magma is coming to the surface plates are coming together crust is returning to the mantle plates are slipping past each other crust is not created or destroyed

A Divergent B Convergent C Transform Continental crust  rift valley Oceanic crust  mid-ocean ridge 2 continental plates  mountain range Plates move against each other Stress builds up Stress is released earthquake 2 oceanic plates or oceanic + continental subduction

Plate Tectonics Vocabulary Fault: a crack or fracture in the Earth’s crust along which movement, dislocation and overlaps of plates occur. Plate Boundary: Where two or more plates meet

Transform Convergent Divergent