Chapter 14 Answers to Review Questions

Chapter 14 Answers to Review Questions - Chapter 14 Answers...

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Chapter 14 Answers to Questions for Review 1. The study of the geological evidence left behind by advancing and retreating glaciers; collection of fossil pollen of tundra plants; core samples taken from ocean floor sediments and Greenland and Antarctica ice; the study of annual growth rings of trees; documents concerning droughts, floods, and crop yields; the study of oxygen-isotope ratios of corals; borehole temperature profiles. 2. The most recent North American glaciers reached their maximum thickness and extent about 18,000 to 22,000 years ago. At that time, the sea level was perhaps 120 m (395 ft) lower than it is now. The lower sea level exposed vast areas of land, such as the Bering land bridge, a strip of land that connected Siberia to Alaska, which allowed human and animal migration from Asia to North America. 3. It is significantly higher. 4. The Younger-Dryas was a cold spell lasting from about 12,700 to 11,700 years ago. 5. A positive feedback mechanism is a process which is reinforced by other processes. A negative feedback mechanism is a process which is weakened by interactions among other variables. The water vapor-temperature increase process is a positive feedback mechanism. 6. According to plate tectonics, the now existing continents were at one time joined together in a single huge continent, which broke apart. Its pieces slowly moved across the face of the earth, thus changing the distribution of continents and ocean basins. We find glacial features near sea level in Africa today, suggesting that the area underwent a period of glaciation hundreds of millions of years ago. Were temperatures at low elevations near the equator ever cold enough to produce ice sheets? Probably not. The ice sheets formed when this land mass was located at a much higher latitude. Over the many millions
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This note was uploaded on 06/23/2008 for the course METR 010 taught by Professor Elajoie during the Spring '08 term at San Jose State.

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Chapter 14 Answers to Review Questions - Chapter 14 Answers...

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