APHG Chapter 13 Guided Reading Assignment
1. What key contribution to our planet’s history did Alfred Wegener make?
A. He proposed a hypothesis that would account for the close “fit” of the shapes of the facing continents. His continental drift hypothesis required a preexisting super continent, Pangaea, which split into the continents of the world.
2. In what two ways have humans effected the earth’s environment during our presence on this planet?
A.
1. Long before we became technologically proficient, we exterminated wild life by the millions and burned grasslands and forests by the hundreds of thousands of square miles.
2. The twentieth-century population explosion combined with a rapid escalation in human consumption, magnifies humanity’s impact on the Earth. Adjectives such as “calamitous’ and “catastrophic” are often used to describe this impact.
3. Why is Earth often called the Blue Planet?
A. Because 70 percent of its surface discovered by water, and views from space are dominated by blue hues and swirls of white clouds.
4. Describe the Comet Hypothesis:
A. Proposes that icy comets bombarded the Earth for more than a billion years, while its atmosphere was still thin, accumulating fresh water from space that filled the basins in the formative crust.
5. Define Pacific Ring of Fire:
A. Ocean-girdling zone of crustal instability, volcanism, and earthquakes resulting from the tectonic activity along plate boundaries in the region.
6. When do scientists suggest that Homo sapiens appeared on the Earth?
A. A warming phase that occurred between 120,000 and 100,000 years ago.
7. What came close to exterminating humanity about 73,500 years ago?
A. Mount Toba erupted. This was not just an eruption: the entire mountain exploded, sending millions of tons of debris into orbit, obscuring the sun, creating long-term darkness, and altering global climate.
8. What do some bio geographers suggest the next great extinction may be caused by?
A.