Japanese Island Swallows Another

Japanese Island

An island off the coast of Japan swallowed another this week. Niijima, a Japanese island that did not exist until November keeps growing and has now overtaken its former neighbor, Nishino-shima.

When one thinks of how an island chain like Hawaii or Japan is formed, one thinks in terms of centuries. A lot of the islands in the area of Niijima formed tens of thousands of years ago. However, back in the 1970s and now again, the underwater volcanic action off Japan provides an amazing real-time show in how land masses are formed and change.

Niijima popped out of the water last November 21 about 440 yards from the coast of Nishino-shima. Since then, Niijima has continued to grow unabated from a tiny speck about 20 meters high to its current height, which NASA estimates at 60 meters (about 200 feet) above sea level. It has also grown 30 times larger overall and merged with its neighbor. Niijima continues to erupt steadily and add more land mass to the new combined island, which is about 3,280 feet across now.

Nishino-shima was not that old. It was formed by at eruption 40 years ago, but the area had been quiet since.. It still has a volcanic cone, but is largely being engulfed by ash and lava from Niijima. NASA’s Landsat has captured numerous images over the past few months showing the changes as well as the volcanic plume rising up into the atmosphere as the one Japanese island comes to life and swallows another.

Niijima is located in the Bonin Island chain, which is also known as the Ogasawara Islands in Japan. About 600 miles south of Tokyo, in the Philippine Sea, the Ogasawara National Park area is part of the Pacific “Ring of Fire” seismic action area. The archipelago of more than 30 subtropical and tropical islands was formed by ancient volcanoes along the sea floor. Only three of the islands are inhabited by humans. However, the island chain is home to 14 types of species that evolved there isolated and never mixed with species elsewhere. The animals are now protected. The archipelago also has more than 100 indigenous plants. The ocean water around the islands is very clear and full of coral reef and tropical fish, so it is a tourist area for diving, swimming with dolphins, whale watching … and now Niijima watching.

When Niijima emerged last fall, scientists thought it would be a tiny islet of ash and lava that would erode and disappear within a few years. Now, with the nonstop volcanic activity, they are not sure what will eventually happen in the area or if the combined island will be a permanent addition to the Japanese island chain.

The fascinating photos and activity in just the past five months illustrates that Earth is an active planet that is still constantly changing. While schoolbooks teach that the changes happen gradually over time, Niijima is allowing people to view the geologic changes as they unfold. It is anybody’s guess how big the new merged island will become and for how many more months, or years, the volcanic show will continue. But, with modern satellite imagery, everyone has a ringside seat to watch one Japanese island completely swallow and cover up another.

By Dyanne Weiss

Sources:
CNN
Japanese Tourism Organization
Science World
Slate

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