1. Earth’s interior

2. Geologist have used evidence to learn about the Earth’s interior: Direct evidence and indirect evidence. Geologist have used evidence to learn about the Earth’s interior: Direct evidence and indirect evidence.

3. Earth’s Center Three main layers of Earth crust, mantle and core. Three main layers of Earth crust, mantle and core. The deeper you go temperature increases as well as, pressure. The deeper you go temperature increases as well as, pressure. The Crust is a solid layer of rock that includes both dry land and ocean floor. On the crust you find rocks and mountains. The Crust is a solid layer of rock that includes both dry land and ocean floor. On the crust you find rocks and mountains. The mantle is made up of rock that is very hot, but solid. The mantle is made up of rock that is very hot, but solid. The core is made mostly of the metals iron and nickel. It consist of a liquid outer core and solid inner core. The core is made mostly of the metals iron and nickel. It consist of a liquid outer core and solid inner core. Scientist think that movements in the liquid outer core create Earth's magnetic field. Since Earth has a magnetic field,the planet acts like a giant bar magnet. Scientist think that movements in the liquid outer core create Earth's magnetic field. Since Earth has a magnetic field,the planet acts like a giant bar magnet.

4. Convection Currents in Earth As material deep in the mantle is heated, it becomes less dense and rises. At the same time, material nearer Earth's surface spreads out, cools, and becomes denser. This denser materials sinks below the hotter, less dense material. Uneven heating causes material in the mantle to constantly slowly rise and fall in convection currents. As material deep in the mantle is heated, it becomes less dense and rises. At the same time, material nearer Earth's surface spreads out, cools, and becomes denser. This denser materials sinks below the hotter, less dense material. Uneven heating causes material in the mantle to constantly slowly rise and fall in convection currents.

5. Drifting Continents Alfred Wegner’s hypothesis was that all the continents were once joined together in a single landmass and have drifted apart. Alfred Wegner’s hypothesis was that all the continents were once joined together in a single landmass and have drifted apart. The continents that drifted together to form the super continents Pangea. The continents that drifted together to form the super continents Pangea. Wegner gathered evidence from different scientific fields to support his ideas about continental drift. He studied land features, fossils and evidence of climate change. Wegner gathered evidence from different scientific fields to support his ideas about continental drift. He studied land features, fossils and evidence of climate change. Wegner’s Hypothesis was rejected because he could not provide a satisfactory explanation for the force that pushes or pulls the continents.Wegner could not identify the cause of continental drift, most geologist rejected his idea. Wegner’s Hypothesis was rejected because he could not provide a satisfactory explanation for the force that pushes or pulls the continents.Wegner could not identify the cause of continental drift, most geologist rejected his idea.

6. Sea-Floor Spreading Mid-ocean ridges are underwater mountains. Mid-ocean ridges are underwater mountains. Mid- ocean ridge curve like the seam of a baseball along the sea floor. They extend into all of the Earth’s ocean. Mid- ocean ridge curve like the seam of a baseball along the sea floor. They extend into all of the Earth’s ocean. Oceanic crust created along the mid-ocean ridge is destroyed at deep-ocean trench. In the process of subduction, oceanic crust sinks down beneath the trench into the mantle. Oceanic crust created along the mid-ocean ridge is destroyed at deep-ocean trench. In the process of subduction, oceanic crust sinks down beneath the trench into the mantle. Because of the sea-floor spreading, the distance between Europe and North America is increasing by a few centimeters per year. Because of the sea-floor spreading, the distance between Europe and North America is increasing by a few centimeters per year.

7. The Theory of Plate Tectonics The uppermost part of the mantle is very similar to the crust. The uppermost part of the mantle and the crust together form a rigid layer called the lithosphere. The uppermost part of the mantle is very similar to the crust. The uppermost part of the mantle and the crust together form a rigid layer called the lithosphere. A scientific theory is a well-tested concept that explains a wide range of observations. A scientific theory is a well-tested concept that explains a wide range of observations.

8. The Theory of Plate Tectonic States that pieces of Earth’s lithosphere are in slow, constant motion, driven by convection currents in the mantle. States that pieces of Earth’s lithosphere are in slow, constant motion, driven by convection currents in the mantle. The theory of plate tectonics explains the formation,movement and subduction of Earth’s plates. The theory of plate tectonics explains the formation,movement and subduction of Earth’s plates. The plates move, they collide, pull apart, or grind past each other producing changes in Earth’s surface. Example: volcanoes, mountain ranges and deep ocean trenches The plates move, they collide, pull apart, or grind past each other producing changes in Earth’s surface. Example: volcanoes, mountain ranges and deep ocean trenches

9. Faults Faults are large cracks in the Earth's crust where rocks have slipped past each other. Faults are large cracks in the Earth's crust where rocks have slipped past each other. The plates move at a slow rate: from 1 to 24 cm per year. The plates move at a slow rate: from 1 to 24 cm per year. The North American and Eurasia plates are moving apart at a rate of 2.5 cm per year. The North American and Eurasia plates are moving apart at a rate of 2.5 cm per year. The plates have been moving apart for tens of millions of years. The plates have been moving apart for tens of millions of years.

10. Plate Boundaries Seven major plates: Pacific, North American, South American, Eurasian, Indo-Australian and Antarctic. Seven major plates: Pacific, North American, South American, Eurasian, Indo-Australian and Antarctic. Three kinds of plate boundaries: Divergent, convergent and transform boundaries. Three kinds of plate boundaries: Divergent, convergent and transform boundaries.

11. Divergent Boundary The place where two plates move apart or diverge. The place where two plates move apart or diverge. Most divergent boundaries occur in the mid-ocean ridge. Most divergent boundaries occur in the mid-ocean ridge. Divergent boundaries also occur on land. It forms a deep valley called a rift valley. Divergent boundaries also occur on land. It forms a deep valley called a rift valley.

12. Convergent Boundaries The place where two plates come together or converge. When the two plates converge, the results is called collision. The place where two plates come together or converge. When the two plates converge, the results is called collision. When the two plates collide, the density of the plates determines which one comes out on top. When the two plates collide, the density of the plates determines which one comes out on top. Example: Sometimes a plate that carries ocean crust collides with a plate carrying continental crust. Oceanic crust is more dense than continental crust. Subduction occurs. Example: Sometimes a plate that carries ocean crust collides with a plate carrying continental crust. Oceanic crust is more dense than continental crust. Subduction occurs.

13. Transform Boundaries A transform boundary is a place where two plates slip past each other, A transform boundary is a place where two plates slip past each other, moving past each other, moving in opposite directions. moving past each other, moving in opposite directions. Earthquakes often occur along the transform boundaries, but crust is neither created or destroyed. Earthquakes often occur along the transform boundaries, but crust is neither created or destroyed. The transform boundary between the Pacific and North American plates is moving LA north toward San Francisco at a rate of 5 cm per year. At this rate it will take the two cities about 11 million years to be side by side.