Homework 1a-Environ Geology

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Homework 1a-Environ Geology

By | March 2013
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Answers:

1) Things that decrease population growth rates are famine, natural disasters, and spread of diseases. Additional causes are man-made disasters such as building near a ridge or living near a polluted river used for drinking water, and access to or depletion of resources. More people are located in areas where natural disasters commonly occur and this fact is yielding higher death rates with each event or cycle.

2) The mortality rates are higher than the birth rates each year. This leads to a decrease in population each year.

3) Fritz Haber discovered how to bond Nitrogen and Hydrogen to produce ammonia. Not only could fertilizers be made but explosives and chemical weapons were made with nitrogen for war time. Fertilizer runoff also pollutes streams, lakes, and oceans and becomes a man-made hazard for fish and anything locally utilizing the resource. This “mixed blessing” is the good and bad that ammonia brings through its many uses.

4) There are 3 plate boundaries and associated forces causing plates to move at boundaries. These are transform, divergent and convergent plate boundaries.

a. Transform plate boundaries occur where plates slide along transform faults (ex: San Andreas Fault).

b. Divergent plate boundaries occur where two plates slide apart from each other. (ex: mid ocean ridges such as the Mid-Atlantic Ridge)

c. Convergent plate boundaries occur where two plates slide towards each other causing a plate collision or where one plate slides under the other (ex: Andes Mountain Range in South America)

5) When a crustal block or fragment of terrane, having its own distinctive geologic history, is broken off from one tectonic plate and lies on top of another plate. This fragment is unique to the surrounding area hence being termed “exotic” to the environment in which it was placed by plate tectonic movement. These scattered fragments, like fossils carried away from Pangaea to new...