The New Hebrides Trench is an

oceanic trench Oceanic trenches are prominent long, narrow topographic depressions of the ocean floor. They are typically wide and below the level of the surrounding oceanic floor, but can be thousands of kilometers in length. There are about of oceanic tren ...

which extends to over deep in the

Southern Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

. It lies to the northeast of

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

and the

Loyalty Islands The Loyalty Islands Province ( French ''Province des îles Loyauté'') is one of three administrative subdivisions of New Caledonia encompassing the Loyalty Island (french: Îles Loyauté) archipelago in the Pacific, which are located northeast of ...

, to the southwest of

Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...

, east of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, and south of

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

and the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capita ...

. The trench was formed as a result of the

subduction zone Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

. The

Australian Plate The Australian Plate is a major tectonic plate in the eastern and, largely, southern hemispheres. Originally a part of the ancient continent of Gondwana, Australia remained connected to India and Antarctica until approximately when India broke ...

is being subducted under the

New Hebrides Plate The New Hebrides Plate, sometimes called the Neo-Hebridean Plate, is a minor tectonic plate located in the Pacific Ocean, near the island country of Vanuatu. The plate is bounded on the southwest by the Indo-Australian Plate which is subducting ...

causing

volcanism Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called ...

which produced the Vanuatu archipelago. The trench was first explored in 2013 by the

University of Aberdeen The University of Aberdeen ( sco, University o' 'Aiberdeen; abbreviated as ''Aberd.'' in List of post-nominal letters (United Kingdom), post-nominals; gd, Oilthigh Obar Dheathain) is a public university, public research university in Aberdeen, Sc ...

's Oceanlab team. They found

cusk-eels The cusk-eel family, Ophidiidae, is a group of marine bony fishes in the Ophidiiformes order. The scientific name is from the Greek ''ophis'' meaning "snake", and refers to their eel-like appearance. True eels, however, diverged from other ray-fi ...

, prawns, and other eels, and crustaceans. This is significantly different from other deep sea trenches that have been studied.

Tectonics

At the New Hebrides Trench, the Australian plate is being subducted underneath the New Hebrides microplate. The convergence rate ranges from /yr in the south, to /yr in the central section, to /yr in the north. The anomalous lack of convergence in the central section is caused by the subduction of the

d'Entrecasteaux Ridge The d'Entrecasteaux () Ridge (DER) is a double oceanic ridge in the south-west Pacific Ocean, north of New Caledonia and west of Vanuatu Islands. It forms the northern extension of the New Caledonia–Loyalty Islands arc, and is now actively su ...

Associated seismicity

Major earthquakes associated with the subduction zone:

References

{{coord, -20, 168, region:XP_source:wikidata, display=title Geology of New Caledonia Geology of the Pacific Ocean Loyalty Islands Oceanic trenches of the Pacific Ocean Subduction zones