1. Warm-Up # 46 What is a galaxy? millions or billions of stars, gas and dust, held together by gravitational attraction

2. What have many irregular shaped galaxies been involved in? COLLISION with Another galaxy WARM-UP #47

3. 1)Background radiation. This radiation, a type of energy, is believed to be left over from the actual Big Bang. 2)The expansion of the universe. This means the distance between galaxies is increasing over time. Warm-Up # 48 What evidence is there for the Big Bang Theory???

4. How old is the universe? WARM-UP #50

5. The first man made object ever sent into space was in 1957 when the Russian satellite named Sputnik was launched. WARM-UP #49

6. ABOUT 14 BILLION YEARS Warm-Up # 50 How old is the universe?

7. Why are the spectra of galaxies shifted toward the red end? They show redshift because they are moving away from us. WARM-UP #51

8. WARM-UP # 52 What is ONE piece of evidence that the continents were once all joined together? You know two – fit together like a puzzle and matching fossil evidence.

9. WARM Up # 53 Who proposed the theory of continental drift? Alfred Wegener proposed the theory of continental drift in 1912. He was a German scientist.

10. What is the theory of seafloor spreading and what scientist developed this theory? Warm-Up # 54 Scientists found that the youngest rocks are located at the mid-ocean ridges. It was discovered by Henry Hess.

11. Warm-Up # 56 Seafloor spreading (Hess) and continental drift (Wegner) What are the two theories that when combined make up the theory of plate tectonics?

12. Warm-Up # 55 Label the three major layers of earth on this diagram:

13. Warm-Up # 57 A. What theory of explains why the seafloor has both trenches and mid-ocean ridges? B. Evidence that tectonic plates are being created at divergent boundaries is that _______ rocks are found at the mid-ocean ridges and ______________rocks are found further away. C. What is the name of the one large supercontinent that existed millions of years ago? Seafloor spreading younger older Pangea

14. Warm-Up # 58 What is the name of the most famous transform fault (plate boundary) in the world? San Andreas Where is it? California What is a transform fault? A plate boundary where the plates grind past each other (not toward or away from each other).

15. February 20 Warm-Up # 59 What is hot, melted rock under the surface of the Earth known as??? MAGMA. Hot, melted rock on the surface of Earth is known as LAVA

16. February 20 Warm-Up # 60 What are climate clues???? Wegner found fossils of the same organism but in very different climates – like a tropical plant in a polar region or a glacial (glacier) deposit in a tropical region.

17. Warm-UP # 61 Two plates in California form a transform fault. The Pacific Plate moves toward the North American Plate causing earthquakes along the fault. Why are there so many earthquakes in California?

18. 18 WARM-UP # 62 Which earthquake wave travels the slowest? Primary Waves (p-waves) are the slowest. Which earthquake wave is the most destructive? Surface/Land Waves (L-waves are the most destructive.

19. 19 WARM-UP # 63 What scale is used to compare the strengths of earthquakes ? The Richter magnitude scale is used to describe the strength of an earthquake and is based on the height of the lines on the seismogram.

20. 20 WARM-UP # 64 What is the difference between the focus of an earthquake and the epicenter of an earthquake? The focus is UNDERGROUND. It is the place on the Earth’s crust where the pressure was released. The Epicenter is the spot on the Earth’s surface directly above the focus.