The Layers of the Earth –Movie Trailer 1. List as many words you’ve heard in science this year as you can. 2. Compare list with your group members 3. Now define the words on your list together 4. The group with the most words defined correctly wins their choice of a Homework Pass, Science Buck or a Piece of Candy
What are the big land masses that stick out of the ocean called? What happens to warm air in your house during the winter? Why is it warmer upstairs in a house than downstairs?
The Four Layers 1. Lithosphere - the crust is the layer that you live on 2. Asthenosphere – the mantle is much hotter and has the ability to flow. 3. Outer core and inner core are even hotter with pressures so great you would be squeezed into a ball smaller than a marble if you were able to go to the center of the Earth!
The Crust The Earths Crust is like the peel of an orange. It is very thin in comparison to the other three layers. The crust is only about 3- 6.5 miles thick under the oceans (oceanic crust - basalt) 25 miles thick under the continents (continental crust - granite). Made of granite and basalt
1. The Lithospheric PlatesThe crust of the Earth is broken into many piecescalled plates. The plates "float" on the soft, semi-rigid asthenosphere.
2. The Asthenosphere •The asthenosphere is the semi-rigid part of the middle mantle that flows like hot asphalt under a heavy weight. •Draw this diagram
The Lithosphere The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the Lithosphere. Draw this diagram
The Crust (Lithosphere) The crust is composed of two rocks. The continental crust is mostly granite. The oceanic crust is basalt. Basalt is much denser than the granite. Because of this the less dense continents ride on the denser oceanic plates.
The Middle Mantle(Asthenosphere) The Mantle is the largest layer. Made of very hot, dense rock that flows like asphalt Its movement is the reason the crustal plates of the Earth move.
Viscosity of the Mantle •Viscosity means thickness. •Mantle = thick. •Has a high viscosity.
Convection Currents The middle mantle "flows" because of convection currents. Convection currents - caused by the very hot material at the deepest part of the mantle rising, then cooling and sinking again --repeating this cycle over and over.
Now Let’s Try It Convection Current Demonstration Room Temperature Water Hot Plate with Boiling Water Room Temperature Water with food Coloring
Convection Currents The next time you heat anything like soup or water in a pan you can watch the convection currents move in the liquid. When the convection currents flow in the asthenosphere they also move the crust. The crust gets a free ride with these currents, like the cork in this illustration. Let’s try it. Safety Caution: Don’t get your face too close to the boiling water!
Classwork – Layers of Earth Use the fact sheet to help you complete the classwork. Turn in
Exit Ticket – Wrap Up Compare the lithosphere to the asthenosphere. ◦ What is different? ◦ What is the same? Lithosphere Asthenospher e Both
Homework Theory of Plate Tectonics – Preview For Next Class Meeting See how many you remember from previous years.