Izu–Ogasawara Trench

{{short description|An oceanic trench in the western Pacific, consisting of the Izu Trench and the Bonin Trench}}

File:Map00148 (28286522445).jpg

The {{Nihongo|Izu–Ogasawara Trench|伊豆・小笠原海溝|Izu–Ogasawara Kaikō}}, also known as Izu–Bonin Trench, is an oceanic trench in the western Pacific Ocean, consisting of the Izu Trench (at the north) and the Bonin Trench (at the south, west of the Ogasawara Plateau).{{cite web|title=Locator map|url=http://www.soest.hawaii.edu/expeditions/mariana/images/regional_locator.jpg|website=Expedition to the Mariana forearc|publisher=School of Ocean and Earth Science and Technology at the University of Hawaii}}

It stretches from Japan to the northernmost section of Mariana Trench.{{Cite web |url=http://www.agu.org/pubs/crossref/2000/1999JC900324.shtml |title=Deep current structure above the Izu-Ogasawara Trench |access-date=2008-03-04 |archive-date=2012-03-01 |archive-url=https://web.archive.org/web/20120301205341/http://www.agu.org/pubs/crossref/2000/1999JC900324.shtml |url-status=dead }} The Izu–Ogasawara Trench is an extension of the Japan Trench. Here, the Pacific plate is being subducted beneath the Philippine Sea plate, creating the Izu Islands and Bonin Islands on the Izu–Bonin–Mariana Arc system.{{Cite web |url=http://www.terrapub.co.jp/journals/EPS/pdf/2006e/5808e033.pdf |title=Crustal structure of the ocean-island arc transition at the mid Izu-Ogasawara (Bonin) arc margin |access-date=2008-03-04 |archive-date=2017-10-29 |archive-url=https://web.archive.org/web/20171029065154/http://www.terrapub.co.jp/journals/EPS/pdf/2006e/5808e033.pdf |url-status=dead }}

It is {{Convert|9826|m|ft|0}} +/- 11m at its deepest point and first dived to its base on August 13, 2022, during a joint Caladan Oceanic/University of Western Australia expedition in the Deep Submergence Vehicle Limiting Factor. The pilot on the mission was Victor Vescovo with scientific mission specialist Professor Katsuyoshi Michibayashi of Nagoya University. On this dive, Prof. Michibayashi became the deepest-diving Japanese person in history.{{Cite web |last=Caladan Oceanic |date=October 3, 2022 |title="Caladan Oceanic Completes a Two Month Expedition with the Japanese Marine Science Community" |url=https://www.dropbox.com/s/cstweugnjcsial9/Caladan%20Oceanic%20-%20press%20release%20-%20Japanese%20trenches%20-%20October%202022%20.pdf?dl=0 |access-date=June 4, 2023}} Also in August 2022, the deepest fish ever recorded on camera was filmed in the trench, a juvenile snailfish, at a depth of 8,336 meters.{{Cite web |last=Metcalfe |first=Tom |title=Deepest Fish Discovered More Than 5 Miles below the Sea Surface |url=https://www.scientificamerican.com/article/deepest-fish-discovered-more-than-5-miles-below-the-sea-surface1/ |access-date=2023-06-04 |website=Scientific American}}

The xenophyophore Occultammina was first discovered at a depth of 8260 metres in the trench.{{Cite journal|last=Tendal|first=Os|last2=Swinbanks|first2=Dd|last3=Shirayama|first3=Y.|date=1982-01-01|title=A new infaunal xenophyophore (xenophyophorea, protozoa) with notes on its ecology and possible trace fossil analogs|url=https://archimer.ifremer.fr/doc/00120/23170/|journal=Oceanologica Acta|volume=5|issue=3|pages=325–329|issn=0399-1784}}