Fukutoku-Okanoba

Fukutoku-Okanoba
The eruption smoke rises, and the fountain is emitted from the inside, giving it a coxtail shape on January 20, 1986
Highest point
Elevation−29 metres (−95 ft)[1]
Coordinates24°16′48″N 141°29′06″E / 24.28°N 141.485°E / 24.28; 141.485
Geography
Fukutoku-Okanoba is located in Japan
Fukutoku-Okanoba
Fukutoku-Okanoba
Geology
Mountain typeSubmarine volcano
Last eruptionAugust 2021

Fukutoku-Okanoba (福徳岡ノ場) is a submarine volcano that is part of the Volcano Islands in the Bonin Islands of Japan. It is located five kilometers (3.1 mi) northeast of the island of South Iwo Jima.

Geography

The volcano is part of a larger elongated submarine volcano with two peaks and with a magma composition of trachyandesite. The volcano itself has erupted on multiple occasions with the last eruption before 2021 occurring during 2010. The first island to form when this volcano was discovered formed in 1904–5 and with a few more forming during the course of the 1900s.[2]

History

The earliest recorded eruption of Fukutoku-Okanoba in 1904 formed an ephemeral island named Shin-Iwo-jima (New Sulfur Island). Other ephemeral islands have also formed, the most recent of which formed in 1986.[3] In 2010, the Japanese coast guard spotted steam rising one kilometer (0.62 mi) above the ocean and water discoloration of the surrounding area.[1] In 2021, the Japan Meteorological Agency (JMA) reported that a submarine eruption occurred at Fukutoku-Okanoba volcano at 6:20 a.m. local time on August 13.[4] On August 16, it was confirmed that a new island had formed as a result of the latest eruption.[5]

In October 2021, large quantities of pumice pebbles from Fukutoku-Okanoba damaged fisheries, tourism, the environment, 11 ports in Okinawa and 19 ports in Kagoshima prefecture.[6] Clean-up operations took 2–3 weeks.[6]

Timeline

  • 1904-1905 : An island roughly 145 m (476 ft) in height and 4.5 km (2.8 mi) in circumference is formed by an undersea eruption.[7] By June 1905, it shrinks to less than 3 m (9.8 ft) high and eventually collapses into a reef.
  • 1914 : An island with a height of 300 m (980 ft) and a circumference of 11.8 km (7.3 mi) is formed by a undersea eruption in January.[7] By the end of the year, it begins to collapse.
  • 1916 : The island is collapses.
  • 1986 : An island is formed by a undersea eruption in January, quickly submerging by the end of March.[7]
  • 2005 : An undersea eruption on July 2 creates a huge water vapor column with 1,000 m (3,300 ft) high and 50–100 m (160–330 ft) wide.
  • 2007 : On December 1, the Japan Meteorological Agency begins announcing eruption warnings for all active volcanoes in Japan, continuing to monitor the Fukutoku-Okanoba area ever since.
  • 2008 : Discolored water is observed for several months starting around February.[8]
  • 2010 : Due to an undersea eruption on February 3, eruptions and discolored water are observed in the surrounding area.[9][10]
  • 2013 : On September 27, observations by the Japan Maritime Self-Defense Forces confirm a green discoloration of the sea surface and the eruption of white foam on the sea surface within a radius of 450 m (1,480 ft).[11]
  • 2020 : On February 4, the Japan Coast Guard observes yellow-green discolored water in the area.
  • 2021 : On August 13, smoke from an undersea eruption of the seafloor is observed rising about 17,000 m (56,000 ft) high, in addition to volcanic lightning. Initially, volcanic ash crosses the Bashi Channel and enters the South China Sea.[12] This eruption is considered to be one of the largest in Japan after the Second World War.[13] Observations by the Japan Coast Guard on August 15 confirm a new island roughly 1 km (0.62 mi) in diameter.[14] On August 17, the new island had split into two parts, east and west, and on October 20 it was confirmed that the eastern side had disappeared.[13] In October, a large amount of pumice believed to have come from this eruption is found to have drifted over 1,000 km (620 mi) away to the Daito Islands and Ryukyu Islands.[13][15][16]
  • Eruption situation of Fukutoku Okanoba (Jan 20, 1986)
    Eruption situation of Fukutoku Okanoba (Jan 20, 1986)
  • Fukutoku Okanoba and South Iwo Jima during eruption activity (Jan 20, 1986)
    Fukutoku Okanoba and South Iwo Jima during eruption activity (Jan 20, 1986)
  • Pumice stones lifted by the eruption fill the surface of the sea. The distant island is South Iwo Jima (Jan 20, 1986)
    Pumice stones lifted by the eruption fill the surface of the sea. The distant island is South Iwo Jima (Jan 20, 1986)
  • Himawari-8 satellite images of the August 12 to August 13, 2021 eruption of Fukutoku-Okanoba
    Himawari-8 satellite images of the August 12 to August 13, 2021 eruption of Fukutoku-Okanoba

See also

References

  1. ^ a b "Fukutoku-Oka-no-Ba". Global Volcanism Program. Smithsonian Institution. Retrieved 2017-02-28.
  2. ^ "Fukutoku-Okanoba". www.volcanodiscovery.com. Archived from the original on 2021-08-16. Retrieved 2021-08-16.
  3. ^ "Fukutoku-Oka-no-Ba: Photo Gallery". Global Volcanism Program. Smithsonian Institution. Retrieved 2021-06-24.
  4. ^ "Fukutoku-Okanoba volcano (Volcano Islands, Japan): submarine explosion today". Volcano Discovery. August 13, 2021. Archived from the original on August 14, 2021. Retrieved August 14, 2021.
  5. ^ "Fukutoku-Okanoba volcano (Japan): new island born in the Pacific". Volcano Discovery. August 16, 2021. Archived from the original on August 21, 2021. Retrieved March 2, 2022.
  6. ^ a b "Japan ports swamped by pumice spewed from undersea volcano". The Guardian. October 30, 2021. Archived from the original on October 30, 2021.
  7. ^ a b c "福徳岡ノ場 有史以降の火山活動". 気象庁. Archived from the original on 2021-08-13. Retrieved 2021-08-16.
  8. ^ "平成20年（2008年）の福徳岡ノ場の火山活動" (PDF). 気象庁地震火山部 火山監視情報センター. Archived (PDF) from the original on 2021-08-13. Retrieved 2021-08-16.
  9. ^ "南硫黄島近海で白煙、新島出現の可能性も". 読売新聞. 2010-02-04. Archived from the original on 2010-02-04. Retrieved 2013-12-25.
  10. ^ "福徳岡ノ場の海底噴火" (PDF). かいほジャーナル. 42 (2010年春号). 海上保安庁: 1. 2010-03-26. Archived from the original (PDF) on 2013-08-24. Retrieved 2013-12-25.
  11. ^ "阿蘇山噴火の可能性 9月の火山活動 気象庁". ハザードラボ. Archived from the original on 2014-03-11. Retrieved 2014-03-11.
  12. ^ "Volcanic Ash Graphic Initial 142100UTC August 2021". VAAC Tokyo. Archived from the original on 2021-08-15. Retrieved 2021-08-14.
  13. ^ a b c "「福徳岡ノ場」噴火、戦後最大級と判明 桜島「大正噴火」に次ぐ規模". 毎日新聞. 2021-10-23. Archived from the original on 2021-10-23.
  14. ^ "海底火山の福徳岡ノ場で新島確認 過去は海没、噴石に警戒". 共同通信. 2021-08-16. Archived from the original on 2021-08-16. Retrieved 2021-08-16.
  15. ^ "沖縄・北大東島を取り巻く灰色ライン 謎の漂着物の正体は?". 琉球新報. 2021-10-08. Archived from the original on 2021-10-08.
  16. ^ "1450キロ離れた沖縄本島にも「軽石」漂着 小笠原の海底火山噴火の影響か". 琉球新報. 2021-10-14. Archived from the original on 2021-10-14.