The result of a rather rare geological phenomenon, a new island a hundred meters long was born in Japan, formed following the eruption of an underwater volcano near the island of Iwo Jima, in the Pacific Ocean.
The eruption in question dates back to last October 21st, when the underwater volcano began to erupt, forming the islet in question in the space of just a week, without causing any damage. The site of the eruption – 1,200 km south of Tokyo – is known for some underwater volcanic activity, being part of the Ogasawara island chain in the western Pacific.
Specifically, the place where the new island was formed is only one kilometer as the crow flies from that of Ioto, known in the West as Iwo Jima – due to a misreading of the Japanese characters – famous for one of the bloodiest battles of the Second World War and for a famous photograph. Thanks to a rather rare geological phenomenon, Japan has therefore added another island to its already numerically rich heritage.
As explained to the Guardian by Fukashi Maeno, associate professor at the University of Tokyo’s Earthquake Research Institute, phreatomagmatic eruptions – a type of explosive eruption that results from the interaction of magma with water – occurred about one kilometer from Ioto, which formed the new continental mass of about 100 meters.
During last month’s eruptions, on site Maeno observed plumes of smoke and ash more than 50 meters high every few minutes as well as large rocks hurtling through the air and bands of brown pumice floating in the sea that had changed color.
Iwo Jima, renamed Iwoto Island by the Japanese authorities in 2007, is one of 111 active volcanoes in the Land of the Rising Sun, itself close to another new island that formed after an eruption in 2021. The new eruption of last month is proof that magmatic activity has returned to the area. The new island could grow and change shape if the eruptions continue, but it could also disappear under the waves, as already happened to those that were created in the area in 1904, 1914 and 1986, a direct consequence of erosion.
According to the latest census of geographers, dating back to the beginning of 2023, based on a recount, Japan has seen its number of islands double compared to the data known so far of four archipelagos and around 6 thousand islands. Using digital mapping technology, the National Information Authority has identified a total of 14,125 islands, 7,273 more than previously thought.