Assignment 1 Miracle Planet Snowball Earth

HOMEWORK 1: “Miracle Planet: Snowball Earth”https://www.youtube.com/watch?v=87hHbiWBwmY

1. How did the gigantic boulders in Central Park in Manhattan get there? What are they called?

2. When was peak of the last glaciation on earth, the peak of the last Ice Age?

3. What do the ancient deposits in Canada from 2.4 billion years ago show?

4. What was Joe Kirschvink able to show about the Precambrian lava flows of the Namibia? What does this tell us about the ancient temperatures at the equator?

5. What was Kirschvink’s proposal based on the data from Canada and Namibia?

6. How thick would be the ice sheet over Tokyo?

7. What does Paul Hoffman think would happen to life in the seas?

8. What gas is produced by decay of organic material? What are methanogens?

9. What does Jim Kasting (the author of your textbook) think about the atmosphere before 2.4 billion years ago?

10. What gas was introduced to the atmosphere when cyanobacteria arose about 2.3 billion years ago? What happened to the methane in the atmosphere? How did the climate of earth respond?

11. What kinds of bacteria survive in the geothermal areas of earth (like Iceland)?

12. How long was life only microbial? What might have triggered a mass extinction of microbes and allowed the expansion of multicellular life?

13. What kind of early fossils were found in Namibia from the end of the second snowball event, about 600 m.y. ago?

14. What is the Ediacaran Period? What kinds of creatures lived then?

15. What is the problem with melting the ice once the entire earth is in “snowball” conditions?

16. What was the level of oxygen before Snowball I? Between Snowball I and II? After Snowball II?

17. What does Kirschvink think got the earth out of the Snowball Earth events, even though the earth was completely ice-covered with a high albedo?Answer: It is the volcanic gases that have carbon dioxide. As these gases rose up, it warmed the Earth and melted the ice.
18. Once the temperature earth rose to melt the snowball ice cover, what would happen to the weather?

19. How does the rise of oxygen after Snowball II affect collagen? What does this do for life?

20. What was Arandaspis?Answer: It is the oldest-known fish with a backbone and no fins. This was considered the closest ancestor of the humans.
21. What does the change in the trilobites in the early Paleozoic suggest about the ecology of seas?

HOMEWORK 2: “How volcanoes froze the earth (twice)”https://www.youtube.com/watch?v=4ONwQV26L-k

1. What is the Cryogenian?

2. What are dropstones? How are they formed? How do we know where on the planet these dropstones were in the Precambrian?

3. What were the names of the two episodes of glaciation of Snowball Earth in the Cryogenian called?

4. Why does the change of the earth’s tilt hypothesis not explain the equatorial glaciers?

5. What does carbonates tell us about the snowball earth events?

6. What is “Slushball Earth”? What is another explanation for the survival of life during the peak of the snowball?

7. What are the two counterbalances that keep the earth from extremes of temperatures?

8. How did the breakup of Rodinia effect the carbon cycle?

9. How dim was the sun during the Cryogenian?

10. What was the influence of the Franklin Large Igneous Province?

11. What are fire fountains? How did they effect the stratosphere?

12. What is the runaway icehouse effect?

13. What eventually warmed the planet and ended each episode of the snowball earth?

14. What is the period after the Cryogenian called? What lived then?