Kermadec Trench

Linear ocean trench in the South Pacific

Kermadec
Trench

Fiji

Lau
Basin

Tonga-
Kermadec
Ridge

Lau-
Colville
Ridge

Tonga
Trench

Osbourn Trough

Louisville

Seamount

Chain

Hikurangi

Trough

New Zealand

The major geological relationships of the Kermadec Trench (violet) which extends south as a continuation of the Tonga Trench (violet) from the Osbourn Trough to the Hikurangi Trough. Blue represents ocean depths of a kilometer or so and brown shades are shallower. Land is shown in dark green and the black line delineates the continent of Zealandia.

Map of the Kermadec Trench and Tonga Trench, north of New Zealand, near Fiji, Tonga and American Samoa. This map can be enlarged if required.

The Kermadec Trench is a linear ocean trench in the south Pacific Ocean. It stretches about 1,000 km (620 mi) from the Louisville Seamount Chain in the north (26°S) to the Hikurangi Plateau in the south (37°S), north-east of New Zealand's North Island.[1] Together with the Tonga Trench to the north, it forms the 2,000 km (1,200 mi)-long, near-linear Kermadec-Tonga subduction system, which began to evolve in the Eocene when the Pacific plate started to subduct beneath the Australian plate. Convergence rates along this subduction system are among the fastest on Earth, 80 mm (3.1 in)/yr in the north and 45 mm (1.8 in)/yr in the south.[2]

## Geology

[edit]

The Kermadec Trench is one of Earth's deepest oceanic trenches, reaching a depth of 10,047 metres (32,963 ft).[3] Formed by the subduction of the Pacific plate under the Indo-Australian plate, it runs parallel with and to the east of the Kermadec Ridge and island arc. The Tonga Trench marks the continuation of subduction to the north.

The Kermadec Trench has a southern continuation in the turbidite-filled Hikurangi Trough, but a series of seamounts on the Australian plate act as a dam and prevents this turbidity from reaching the sediment-starved Kermadec Trench. Debris from a larger subducted seamount probably dammed the trench from 2 Ma to 0.5 Ma and similar events probably redirected sediments in similar ways before that.[4]

Two oceanic plates meet at the Kermadec Trench which is located far from any larger landmass. Because of this, the Pacific plate as well as the trench itself is only covered by c. 200 m (660 ft) of sediments. The trench is almost perfectly straight and its simple geometry is the result of the uniformity of the subducting sea-floor. This sea-floor formed at the extinct Osbourn Trough, located just north of the Louisville Seamount Chain. Abyssal hills on the subducting sea-floor are oriented perpendicular to the old spreading centre and the sea-floor is 72–80 Ma near the Louisville seamounts at the northern end and more than 100 Ma near Hikurangi Plateau at the southern end. There are no seamounts on the sea-floor near the Kermadec Trench except one sitting on the trench slope at 31°30′S 176°27′W﻿ / ﻿31.50°S 176.45°W﻿ / -31.50; -176.45 which has been dated to 54.8±1.9 Ma.[1]

The Hikurangi Plateau formed part of the Ontong-Java-Manihiki-Hikurangi large igneous province (LIP) during the Ontong Java Event 120 Ma. The Manihiki Plateau is currently subducting under the southern part of the Kermadec Arc but most of it has already been subducted. The LIP-arc collision occurred 250 km (160 mi) north of its present location, but oblique plate convergence has migrated the subducted plateau southward.[5]

## Fauna

[edit]

In 2012, deep sea researchers discovered individuals of a species of giant amphipod at the trench's lowest depths.[6] Unlike most amphipods, which are approximately 2.5 cm (1 inch) long, this species reaches up to 34 cm (13 inches) in length, and is milky-white.[6]

The second-deepest fish, the hadal snailfish Notoliparis kermadecensis, is endemic to the trench and occupies a very limited depth range, 6,472 to 7,561 m (21,234 to 24,806 ft).[7]

A species of pearlfish, Echiodon neotes, has been caught in the Kermadec Trench at a depth of 8,200–8,300 m (26,900–27,200 ft). All other known pearlfishes live in the range 1,800–2,000 m (5,900–6,600 ft) and the presence of E. neotes at this depth remains unexplained.[8]

## Exploration

[edit]

In May 2014, the Nereus, an unmanned research submarine operated by the Woods Hole Oceanographic Institution (WHOI), imploded due to high pressure at a depth of 9,990 metres while exploring the Kermadec Trench.[9]

In December 2022, a research team from the Chinese Academy of Sciences and National Institute of Water and Atmospheric Research reached the bottom of the Scholl Deep nearly 10 km below the surface.[10]

## See also

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* Kermadec Islands
* Monowai Seamount
* Tonga-Kermadec Ridge

## References

[edit]

Notes

1. ^ a b Billen & Gurnis 2005, p. 9
2. ^ Stratford et al. 2015, p. 4
3. ^ Linley, T.; Stewart, AL; McMillan, PJ; Clark, MR; Gerringer, ME; Drazen, JC; Fujii, T; Jamieson, AJ (2017). "Bait attending fishes of the abyssal zone and hadal boundary: Community structure, functional groups and species distribution in the Kermadec, New Hebrides and Mariana trenches". Deep Sea Research Part I: Oceanographic Research Papers. 121: 38–53\. Bibcode:2017DSRI..121...38L. doi:10.1016/j.dsr.2016.12.009. ISSN 0967-0637.
4. ^ Lewis, Collot & Lallem 1998, Abstract
5. ^ Timm et al. 2014, Abstract; p. 2
6. ^ a b Morelle, Rebecca (2 February 2012). "'Supergiant' crustacean found in deepest ocean". BBC News. Retrieved 13 May 2014.
7. ^ Yancey et al. 2014, Significance; Fig. 1
8. ^ Fujii et al. 2010
9. ^ "Nereus, unmanned research sub, suffers 'catastrophic implosion' nearly 10 kilometres underwater". National Post. Toronto. Associated Press. 12 May 2014. Retrieved 13 May 2014.
10. ^ Cowing, Keith (2022-12-04). "Chinese And New Zealand Scientists Dive to One of the Ocean's Deepest Regions". Astrobiology. Retrieved 2022-12-31.

Bibliography

* Billen, M. I.; Gurnis, M. (2005). "Constraints on subducting plate strength within the Kermadec trench". Journal of Geophysical Research: Solid Earth. 110 (B5). Bibcode:2005JGRB..110.5407B. doi:10.1029/2004JB003308.
* Fujii, T.; Jamieson, A. J.; Solan, M.; Bagley, P. M.; Priede, I. G. (2010). "A large aggregation of liparids at 7703 meters and a reappraisal of the abundance and diversity of hadal fish". BioScience. 60 (7): 506–515\. doi:10.1525/bio.2010.60.7.6. S2CID 85118297. Retrieved 29 April 2017.
* Lewis, K. B.; Collot, J. Y.; Lallem, S. E. (1998). "The dammed Hikurangi Trough: a channel-fed trench blocked by subducting seamounts and their wake avalanches (New Zealand–France GeodyNZ Project)" (PDF). Basin Research. 10 (4): 441–468\. Bibcode:1998BasR...10..441L. doi:10.1046/j.1365-2117.1998.00080.x. S2CID 130811128. Retrieved 29 April 2017.
* Stratford, W.; Peirce, C.; Paulatto, M.; Funnell, M.; Watts, A. B.; Grevemeyer, I.; Bassett, D. (2015). "Seismic velocity structure and deformation due to the collision of the Louisville Ridge with the Tonga-Kermadec Trench" (PDF). Geophysical Journal International. 200 (3): 1503–1522\. doi:10.1093/gji/ggu475. Retrieved 16 April 2017.
* Timm, C.; Davy, B.; Haase, K.; Hoernle, K. A.; Graham, I. J.; de Ronde, C. E.; Woodhead, J.; Bassett, D.; Hauff, F.; Mortimer, N.; Seebeck, H. C.; Wysoczanski, R. J.; Caratori-Tontini, F.; Gamble, J. A. (2014). "Subduction of the oceanic Hikurangi Plateau and its impact on the Kermadec arc" (PDF). Nature Communications. 5: 4923. Bibcode:2014NatCo...5.4923T. doi:10.1038/ncomms5923. PMID 25230110. Retrieved 9 April 2017.
* Yancey, P. H.; Gerringer, M. E.; Drazen, J. C.; Rowden, A. A.; Jamieson, A. (2014). "Marine fish may be biochemically constrained from inhabiting the deepest ocean depths". PNAS. 111 (12): 4461–4465\. Bibcode:2014PNAS..111.4461Y. doi:10.1073/pnas.1322003111. PMC 3970477. PMID 24591588.

## External links

[edit]

* "Kermadec Trench". Woods Hole Oceanographic Institution. Retrieved 9 April 2017. An animation of a 3D model of the Kermadec Trench

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Seismic faults of New Zealand

North Island|

| North Island Fault System|

* Kaweka Fault
* Mohaka Fault
* Patoka Fault
* Ruahine Fault
* Rukumoana Fault
* Te Whaiti Fault
* Waimana Fault
* Waiohau Fault
* Waiotahi Fault
* Wairarapa Fault
* Wellington Fault
* Wheao Fault
* Whakatane Fault

|

Taupō Volcanic Zone (Taupō Rift)|

* Aratiatia Fault
* Edgecumbe Fault
* Matata Fault
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* Haukari West Whangamata Fault
* Horohoro Fault
* Kaiapo Fault
* Karioi Fault
* Ngapouri-Rotomahana Fault
* National Park Fault
* Ohakune Fault
* Orakonui Fault
* Paeroa Fault
* Poutu Fault Zone
* Puketarata Fault
* Rangipo Fault
* Raurimu Fault
* Taupō Fault Belt
* Thorpe - Poplar Fault
* Upper Waikato Stream Fault
* Wahianoa Fault
* Waihi Fault Zone
* Waipuna Fault

Hauraki Rift|

* Firth of Thames Fault
* Hauraki Fault
* Kerepehi Fault

Auckland regional faults|

* Wairoa North Fault

South Island|

| Alpine Fault|

|

Marlborough fault system|

* Awatere Fault
* Clarence Fault
* Elliott Fault
* Hope Fault
* Kekerengu Fault
* Wairau Fault

Canterbury fault system|

* Hundalee Fault
* Christchurch Fault
* Greendale Fault
* Port Hills Fault
* Ostler Fault Zone

Otago fault system|

* Akatore Fault
* Green Island Fault
* Kaikorai Fault
* Titri Fault
* Hyde Fault

Other|

| Predominantly oceanic faults|

* Kermadec–Tonga subduction zone (Hikurangi Margin)
* Macquarie fault zone

|

* Faults in New Zealand
* List of earthquakes in New Zealand
* Pacific plate
* Indo-Australian plate

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Oceanic features of Zealandia

Major divisions|

* Western Province (North Zealandia)
* Eastern Province (South Zealandia)

Plateaux, ridges, and rises|

* Bellona Plateau
* Bounty Platform
* Campbell Plateau
* Challenger Plateau
* Chatham Rise
* Chesterfield Plateau
* Colville-Lau Ridge
* Dampier Ridge
* Fairway Ridge
* Hikurangi Plateau
* Kenn Plateau
* Lord Howe Rise
* Loyalty Ridge
* Mellish Rise
* Norfolk Ridge
* Northland Plateau
* Puysegur Ridge
* Resolution Ridge
* Three Kings Ridge
* West Norfolk Ridge

Troughs and trenches|

* Bellona Gap
* Bellona Trough
* Bounty Trough
* Havre Trough
* Hikurangi Trough
* New Caledonia Trough
* Puysegur Trench

Oceanic basins|

* Bellona Basin
* Campbell Basin
* Canterbury Basin
* Capel Basin
* Cato Basin
* Chatham Slope
* Dampier Basin
* Deepwater Taranaki Basin
* East Coast Basin
* Emerald Basin
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* Faust Basin
* Gower Basin
* Great South Basin
* Middleton Seafloor Basin
* Monowai Basin
* Moore Basin
* New Caledonia Basin
* Norfolk Basin
* Northeast Slope
* Northland Basin
* Outer Campbell Basin
* Pegasus Basin
* Pukaki Basin
* Raukumara Basin
* Reinga Basin
* South Fiji Basin
* South Loyalty Basin
* Taranaki Basin
* Wanganui Basin
* West Coast Basin

Seamounts|

* Banc Capel
* Brothers Seamount
* Clark Seamount
* Flinder's Seamount
* Gifford Guyot
* Graveyard Seamounts
* Havre Seamount
* James Healy Seamount
* Lord Howe Seamount Chain
* Monowai Seamount
* Rumble III Seamount
* Rumble IV Seamount
* Rumble V Seamount
* South Kermadec Ridge Seamounts
* Tangaroa Seamount
* Tasmantid Seamount Chain

Other|

* Alpine Fault
* Hikurangi Margin
* Kermadec Plate
* Maari oil field
* Macquarie fault zone
* Maui gas field
* Pohokura field

31°S 177°W﻿ / ﻿31°S 177°W﻿ / -31; -177
*[c.]: circa
*[Ma]: million year ago
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