As you may have already known, Japan has a lot of active and dormant volcanoes scattered all across its islands. But did you know that Japan is one of those countries that keep increasing its area due to volcanic activity? The Pacific Ring of Fire is a dangerous place in the world with many underwater volcanoes constantly fuming, thus increasing the landmass of Japan, often changing its geographical structure. The most recent island that gained mass is Nishinoshima, aka Rosario Island, which is located in the Ogasawara archipelago of Japan.
Nishinoshima is a small island off the coast of Tokyo to the southeast, located in the Izu-Ogasawara Trench. It is one of those caldera islands that remain silent for a very long time until they viciously start fuming.
After thousands of years of being calm, the 3,000-meter underwater volcano beneath the surface of Nishinoshima became violent, erupting lava and smoke every few minutes between the years 1973 and 1974, and 2013 and 2015. The Japan Coast Guard first identified the eruption by looking at the change in the color of the sea – from blue to yellowish green, with black rocks floating around the sea.
Different cones started to appear on the island, some of them shooting pumice-like rocks up to 300 meters high into the sky. Small new islands, aka craterlets, were formed around the main island of Nishinoshima. Due to the cooling of the lava flows, these smaller islands got merged with Nishinoshima, thus making it larger in size.
Niijima is one of Japan’s short-lived islands, reported first in November 2013, just half a kilometer away from Nishinoshima. In December 2013, its area was just 13.8 acres, but by December 2014, it has reached nearly 570 acres, swallowing the main island itself. There was also a cone formation on the main island of Nishinoshima, whose eruptions elongated the island, and finally merged with Niijima on December 26, 2013.
Many scientists believe that the new islands usually formed as a result of volcanic activity submerge once the rocks start cooling and the height decreases. However, in this case, the height of the island has increased so much that the newly fused Nishinoshima is likely to remain for many years to come. It is said that the area of Nishinoshima has increased approximately 11 times as a result of the merger in just 15 months.
Nishinoshima went into a passive mode for a few months, however, resumed its expansion in April 2017. Nishinoshima continues to expand more and more by extending into different directions. Scientists are stunned by how fast this island is growing, both in terms of height and area.
This island, which was once green and home to rare varieties of seabirds and plants, has become barren due to continuous volcanic eruptions. However, scientists are confirming that some sections of the island are seeing signs of life again.
There are many islands like Nishinoshima that were formed out of volcanic activity in recent times, for example, Surtsey in Iceland, Home Reef in Tonga, etc.
We all know that continents and major islands, including Japan, were formed as a result of seismic and volcanic activities for billions of years. Let’s see how much Nishinoshima is going to expand, and how important it will be for future generations to come. These new islands are called “atarashii shima” in Japanese.
The entire Ogasawara archipelago is filled with mysteries. Plenty of natural wonders, including some rare flora and fauna, can be seen here. There are military helicopter rides and freight ship trips for people who want to see remote islands, including Nishinoshima. However, you cannot get too close to Nishinoshima as you are expected to stay outside the safety radius.