1. Geology Geology-Study of the Earth and it’s processes; includes rocks and minerals, earthquake study and vulconology, and geologic time and fossils.

2. Earth’s Structure Lithosphere: outermost rigid layer of the Earth; made of crust and rigid upper part of mantle Asthenosphere: soft layer of the mantle on which parts of lithosphere move. Mesosphere: strong, lower part of mantle Outer Core: liquid Inner Core: solid; both parts iron with some nickel

3. How do we know? Scientists have used seismic evidence (earthquake waves) to detect what is inside the Earth. As the waves move and change inside, we can measure their changes to determine the materials the waves are passing through or bouncing off of.

4. Earth Has Faults (Doesn’t Everybody?) The Earth’s crust and the upper mantle are broken into fragments called plates. Plates interact and cause geologic features and events. When movement occurs due to this activity, it occurs along joints in the plates called faults.

5. Tennessee’s Faults Tennessee sits in between three geologically active faults: The New Madrid fault, which is in 5 states including W. TN along the Mississippi; and the Appalachians, which experience minor quakes every year. The New Madrid is a major fault line that caused the formation of Reelfoot Lake during a series of major earthquakes in 1811-1812. Tennessee's History

6. Other Earthquakes of Note Earthquake Information for California 1989- Quake in CA caused major damage in Bay Area (San Fran. And Oakland); 63 deaths, thousands of injuries, $6 billion in damage; largest EQ on San Andreas fault since 1906 Prince William Sound, Alaska 1964 March 28 9.2 EQ, causing up to 67 m waves in Valdez, large amount of property damage and a tsunami that traveled all the way to Hawaii and cause ripple effects as far as Puerto Rico

7. Alfred Wegener and Plate Tectonics Wegener proposed hypothesis of continental drift in 1915; he was a meteorologist. He named the large landmass Pangaea, meaning “all earth”. His evidence included: fossils of Glossopteris and Mesosaurus, matching mountain chains on different continents, and similar climate changes on landmasses.

8. Sea-Floor Spreading New ocean crust is formed at mid- ocean ridges as melted material from the mantle is deposited on the sea- floor. Older rocks are farther away, newer rocks closer.

9. Theory of Plate Tectonics This theory states the lithosphere is broken into rigid blocks called plates. Ocean plates are thinner than continental plates.

10. Plate Boundaries Where plates meet. Divergent boundary- where plates are pulled apart. This forms rifts such as the Great Rift Valley in E. Africa.

11. Continued Convergent- Where plates collide. If two continental plates collide mountains form (Himalayas). If an ocean and land plate collide, the ocean plate is subducted (slides under the land) to form a trench. If two ocean plates collide, you also get a trench.

12. continued Transform fault- plates move past one another in the same direction at different rates or opposite directions (San Andreas).

13. Volcanoes Strato-volcanoes: alternating flows of lava and ash. Mt. St. Helens Sheild volcanoes: sloping mountains made from lava. Mauna Loa Cinder-cone volcanoes: violent eruptions that blow out lava as cinders. Paricutin in Mexico

14. Historic Eruptions 1883: Krakatoa in Indonesia sent ash all around the globe; sunsets were strange colored for months. 1989: Wahaula Visitor Center in Hawaii engulfed by lava

15. Advantages of Geologic Activity Iceland: geothermal energy used to heat homes and produce electricity Basalt is a raw material used in cleaning supplies Volcanic glass is used for stone work and has been used for arrowheads