Earth Science

Answer the following questions.

1. Summarize advances over time in determining the age of the Earth, including the importance of the discovery or radioactivity.

Radioactive or radiometric dating allows us to estimate the Earth's age by giving us the actual age of rock within a range of several million years. Radiometric dating is based on the scientific law of radioactive decay and the half-life of radioactive elements. Uranium and some other elements decay into lead over time at a specific rate. Knowing the content of these elements in the makeup of a rock allows its age to be calculated. Currently, the oldest rocks of Earth origin are estimated to be over 4 billion years old.

2. What makes Earth a habitable, relatively stable environment within which we exist and survive? Review the early development of the solar system, including the Big Bang theory, to support your answer.

3. Alfred Wegener was a polar explorer and visionary. Describe how his early work was viewed with skepticism and how ultimately his theory on continental drift was proven. What kinds of evidence did Wegener rely on to substantiate his continental drift hypotheses (Pangaea)?

4. Explain how seismic tomography has been used to show what is actually happening on Earth. Include in your answer a discussion of plate tectonics and sea-floor spreading.

5. Explain how the laws of thermodynamics determine the motions that result in the formation of mountains and oceans.