The Ogasawara Islands, just south of Japan, are a beautiful and geologically active spot. In 2013, members of the Japan Maritime Self-Defence Force noticed a “hot spot” among the islands, near the Nishinoshima volcano. In 2015 they returned, and found a small, entirely new islet, just south of the main volcano.
The researchers describe their findings in the journal Geology. The island started as what’s known as a Surtseyan eruption — a relatively violent underwater eruption of molten basalt. Eventually it created a cone of cooled lava, which prevented water from rushing into the eruption site. It turned into a Strombolian eruption — a steady series of moderate, dry eruptions which build up rock over time.
The result is a small island that looks like a bit of exposed brain floating in the water, thanks to its weird, twisting lava flows. It’s this convoluted tubing that interests the geologists. They have been studying “the development of lobes and tubes from breakouts and bifurcations … that fed lava to the active flow front.” Instead of a straight flow from the mouth of the volcano and into the sea, the lava took twisted paths from the volcano to the front of the flow, where it would eventually cool and turn into stone.
Now who gets naming rights?