1.   Just ahead lay the outlying volcanic islands of To Shima and Nii Shima, and the wind carried us slantwise between them.

2.   This pattern coincides with a number of structural features, including mid-oceanic ridges, mountain belts, oceanic trenches and volcanic island arcs.

3.   Convergent boundaries between oceanic lithosphere are marked by an oceanic trench, a volcanic island arc and a Wadati-Benioff zone.

4.   Consequently, if a volcanic island is to be formed the rate of growth of a volcano must exceed the rate of ocean floor subsidence.

5.   But here, near the town of Bukittinggi in the highlands of Sumatra, a volcanic island about the size of California, there was more.

6.   Lighter minerals floated to the top of the hot, turbulent mantle, forming volcanic islands in the primeval ocean.

7.   No one was prepared, really, for the rocky volcanic island, the fierce Japanese defense, the casualties.

8.   On these volcanic islands, isolation and time conspired to create a vast diversity of unique species.

9.   On bloody Iwo Jima in the North Pacific, U.S. Marines drive the remaining Japanese defenders into a pocket on the northern tip of the tiny volcanic island.