1. Briefly describe how an island arc forms. 2. Why are there expressions such as “solid earth” and “old as the hills,” which suggest that Earth is unchanging? 3. How did seismic waves contribute to...

1. Briefly describe how an island arc forms.

2. Why are there expressions such as “solid earth” and “old as the hills,” which suggest that Earth is unchanging?

3. How did seismic waves contribute to the discovery of Earth’s deep internal layers?