Japan’s impressive archipelago has expanded yet again, as a submarine volcanic eruption, situated approximately 1,200 kilometers (745 miles) to the south of Tokyo, has given rise to a newly formed landmass.
Renowned experts in the field assert that this diminutive island emerged in the wake of a series of volcanic eruptions that commenced in October, near Iwoto Island, a constituent of the Ogasawara island chain, located in the vast expanse of the western Pacific.
Fukashi Maeno, an esteemed associate professor affiliated with Tokyo University’s institute for earthquake research, has officially confirmed the occurrence of phreatomagmatic eruptions, a specific category of explosive volcanic activity resulting from the interaction of magma with water. These eruptions transpired approximately one kilometer off the coast of Iwoto, culminating in the formation of a landmass with a diameter spanning approximately 100 meters.
Maeno, who conducted an aerial survey of the site at the end of October, reported to the Kyodo news agency that plumes of smoke and ash, exceeding 50 meters in height, periodically ascended during the course of these volcanic events.
The eruptions were accompanied by the spectacle of substantial rocks hurtling through the atmosphere and clusters of brown pumice stones adrift in the discolored sea, a consequence of the volcanic activity.
Iwoto, historically known for being the site of one of the most intense battles of the Pacific War and home to one of Japan’s 111 active volcanoes, is located in proximity to another recently formed island that materialized following a volcanic eruption in 2021. Iwoto Island was previously identified as Iwo Jima but was officially renamed by Japanese authorities in 2007.
This region has a history of witnessing dramatic bursts of volcanic activity. Japan’s meteorological agency has documented analogous eruptions in the vicinity of Iwoto between July and December of the preceding year, as well as in June of the current year.
Maeno contends that the recent emergence of this island serves as conclusive evidence of renewed magmatic activity within the area. The newfound island could undergo further expansion and modification if volcanic activity persists, yet it is equally susceptible to being engulfed beneath the ocean’s surface. Historical instances reveal that islands formed in a similar manner in 1904, 1914, and 1986 eventually succumbed to erosion and vanished.
Islands created from ash and rock fragments may face a formidable challenge in withstanding the ceaseless battering of oceanic waves. Nevertheless, continued volcanic eruptions possess the potential to generate lava flows that may eventually solidify into a more enduring and resilient landmass.
In 2013, several weeks of volcanic activity gave rise to an island that subsequently amalgamated with an existing landmass, resulting in the formation of a novel territory that, for a brief period, bore a striking resemblance to the iconic cartoon dog Snoopy.
Earlier this year, geographers made an intriguing revelation by asserting that Japan’s archipelago, traditionally perceived as comprising four principal islands and approximately 6,000 smaller, predominantly uninhabited islets, was, in fact, composed of twice as many landmasses. Utilizing advanced digital mapping technology, the Geospatial Information Authority of Japan identified a total of 14,125 islands, exceeding previous estimates by 7,273.
Nonetheless, Japan occasionally faces the loss of islands. Esanbe Hanakita Kojima, situated 500 meters off the coast of Hokkaido, silently slipped beneath the waves in 2018 without detection. This disappearance remained unnoticed until the author Hiroshi Shimizu embarked on a visit to the area while researching a sequel to his picture book, which explored Japan’s “hidden” islands.
