Pacific Ocean: An Island is Born; The Oceans; Scientific American Presents; by Malahoff; 2 Page(s)

Lying on my left side, peering through the small porthole, I gazed on a fantastic, jagged undersea landscape, just 47 days old. No human had seen it before. I was 1,328 meters (4,357 feet) below the sea, at the very bottom of a brand-new pit crater in Loihi, an undersea volcano 34 kilometers south of the big island of Hawaii.

Before July 16, 1996, the top of Loihi was marked by two pit craters, each about one kilometer in diameter and 300 meters deep, and a large hill, known as a cinder cone, underlain by magma (molten rock). Then, by August 10, and for largely unknown reasons, the magma inside the cone withdrew into the volcano's interior "plumbing," and Pele's Cone, as we called it, collapsed in a volcanic event as cataclysmic as the Mount St. Helens eruption in 1980. Some 300 million tons of rock fell into the volcano, creating a third pit crater, which my colleagues and I now call Pele's Pit.