Earth’s Interior Chapter-1 Section-1

1. Earth’s InteriorChapter-1 Section-1 By: Ms. Vigil Science P-1 9/6/04

2. What is the Science of Geology? Earth’s Interior Chp 1-1 • Earth’s hard surface is formed of rock • Geology is the study of the planet Earth • earth’s landforms are the work of natural forces that slowly build up and wear down the land • The earth looks very different than it did thousands of years ago.

3. What are Surface Changes? Earth’s Interior Chp 1-1 • Constructive forces: shape the surface by building up mountains and landmasses. Example: volcanoes, etc. • Destructive forces: shape the surface by slowly wearing away mountains and other features. EROSION • Example: ocean waves, rain, wind, etc. • Continents

4. Is there indirect evidence of what’s inside the Earth? Earth’s Interior Chp 1-1 • Geologists cannot observe Earth’s interior directly via seismic waves • It is over 6,000 kilometers from the surface to the center of the Earth • Seismic Activity –when earthquakes occur they produce seismic waves • Seismic waves travel through the earth—the speed of the seismic waves and the paths they take reveal how the planet is put together

5. What is Temperature in the Center of the Earth like? Earth’s Interior Chp 1-1 • At first as you descend it becomes cool, however, • 20 meters + rock is getting warmer • For every 40 m descended, the temperature rises 1 degrees celsius

6. What is Pressure in the Center of the Earth like? Earth’s Interior Chp 1-1 • Pressure is the force pushing on a surface area • The deeper you go, the greater the pressure • Three main layers in the Earth • Crust • Mantle • Core

7. What is the Crust? Earth’s Interior Chp 1-1 • The layer of rock that forms Earth’s outer skin • Mountains, rocks, soil & water make-up the surface • Ranges from 5 to 40 kilometers • The crust includes both oceanic crust and continental crust • Basalt –type of rock that is dark and dense with a fine texture – is found primarily on the ocean floor • Granite – type of rock that has large crystals and is light in color and is found primarily on the land

8. What is the Mantle Earth’s Interior Chp 1-1 • A layer of hot rock • Made of two parts major parts at the uppermost part of the Mantle: • Lithosphere and Asthenosphere • Lithosphere • Uppermost part of the mantle and lower part of crust which together form a rigid layer approx. 200 km thick • Lithos means stone • Asthenosphere • Below the lithosphere • Soft like tar—it can bend like plastic

9. What is the core? Earth’s Interior Chp 1-1 • The core consists of two parts: Liquid Outer Core and a Solid Inner Core • Outer Core: • Layer of molten metal that surrounds the inner core –like a thick liquid • Inner Core • Is a dense ball of solid metal • Extreme pressure squeezes the atoms of iron and nickel into a tight solid that can’t become a liquid

10. How does the Earth’s Magnetic Field Work Earth’s Interior Chp 1-1 • Currents in the liquid outer core force the solid inner core to spin at a slightly faster rate than the rest of the planet • These currents in the outer core creates Earth’s magnetic field—causes the earth to act like a gigantic bar magnet

11. Exploring Earth’s Interior pg. 22-23 Earth’s Interior Chp 1-1 • Complete project • Scientific drawings of the Earth’s Interior p.22 and a Cross section from Earth’s surface to the center –pg 23. (These drawings are to be taped or glued into the Science journal)

12. Summarize: HOMEWORK • Geology • Constructive & Destructive Forces • Seismic waves • Temp & Pressure in Earth • Crust • Mantle • Core • Earth’s magnetic field