Slideshow Transcript

1. Slide 1: Earth’s Structure
2. Slide 2: Earth’s Layers • Earth is made of 3 layers – crust, mantle, and core – crust is the layer we walk on • includes the ocean floor and continents – mantle is the layer under the crust • thickest layer of the planet • mostly made of solid rock – some is partly melted and flows very slowly like a thick liquid – core is deep inside the Earth • dense ball made mostly of iron and nickel (metals)
3. Slide 3: Inside the Earth • core can be divided into 2 layers – inner core: solid ball made mostly of iron and nickel • it is the hottest layer of Earth – outer core: pool of hot, liquid metal • mantle – some parts are solid rock – others are partly melted
4. Slide 4: • crust – outer layer – made of rocks and soil – where you live – forms ocean floors
5. Slide 5: How Plates Move • Earth’s crust and upper mantle are broken into continent-sized slabs called plates – plates move slowly across Earth’s surface on a thin layers of partly melted mantle • move only a few centimeters a year
6. Slide 6: • plates can move away from each other – usually happens on the ocean floor – new ocean floor crust forms • ex. Mid-Atlantic Ridge in the Atlantic Ocean • plates can move toward each other – mountains formed this way – sometimes one plate is pushed below the other plate • forms volcanos – crash head on • material on plates wrinkles and forms high mountains • ex. Himalaya Mountains of Asia
7. Slide 7: • plates moving past each other – rocks along cracks stick as plates slide past each other and then move suddenly when they become unstuck – causes earthquakes • ex. San Andreas fault
8. Slide 8: Summary • Earth is made of 3 layers – crust is the outer layer – mantle is the middle layer – core is the inner layer • Earth’s crust and upper mantle are broken into giant plates that move slowly