The South Kermadec Ridge Seamounts are a continuation of the volcanic island arc,[1] formed at the convergent boundary where the Pacific Plate subducts under the Indo-Australian Plate. The subducting Pacific Plate created the Kermadec Trench,[2] the second deepest submarine trench,[3] to the east of the islands. The seamounts lie along the western aspect of the undersea Kermadec Ridge, which runs southwest from the Kermadec Islands towards the North Island of New Zealand and northeast towards Tonga (Kermadec-Tonga Arc).

South Kermadec Ridge Seamounts
Bathymetry of the Kermadec volcanic island arc and surrounding areas
Location
Location	South Pacific Ocean
Coordinates	35°30′S 178°12′E
Geology
Type	Seamount chain

This area of the Kermadec Arc - Havre Trough is a relatively young oceanic arc-back-arc system as it became active in the Quaternary.[4] The seamounts include:[5][4][6][7]

Map of South Kermadec Ridge Seamounts. It is possible by clicking on map to enable mouseover of names.

• Speight Knoll −1,840 metres (−6,037 ft)32.3883°S 179.591°E / -32.3883; 179.591 (Speight Knoll)[7]
• Oliver Knoll −2,200 metres (−7,218 ft)32.39448°S 179.67231°E / -32.39448; 179.67231 (Oliver Knolll)[7]
• Haungaroa Seamount −660 metres (−2,165 ft)32.6152°S 179.6217°E / -32.6152; 179.6217 (Haungaroa Seamount)[7]
• Kuiwai Seamount −560 metres (−1,837 ft)33.159°S 179.9565°E / -33.159; 179.9565 (Kuiwai Seamount)[7]
• Cole Seamount 33.4095°S 179.8715°E / -33.4095; 179.8715 (Cole Seamount)[7]
• Ngātoroirangi Seamount −340 metres (−1,115 ft)33.73533°S 179.79666°E / -33.73533; 179.79666 (Ngatoroirangi Seamount)[7]
• Sonne Seamount 34.066667°S 179.583333°E / -34.066667; 179.583333 (Sonne Seamount)[7]
• Kibblewhite Seamount −990 metres (−3,248 ft)34.5762°S 179.262°E / -34.5762; 179.262 (Kibblewhite Seamount)[7]
• Gill Seamount −1,200 metres (−3,937 ft) 34.62°S 178.375°E / -34.62; 178.375 (Gill Seamount)
  • Situated in the middle of a deep basin (3000m deep) to the west of Kibblewhite and actually closer to the Lau-Colville Ridge than the Kermadec Ridge[4]
• Yokosuka Seamount −1,060 metres (−3,478 ft) 34.7°S 178.57°E / -34.7; 178.57 (Yokosuka Seamount)
  • To west of Brothers situated on an elevated basal plateau (2500m deep)[4]
• Rapuhia Seamount −650 metres (−2,133 ft) 34.77°S 178.5°E / -34.77; 178.5 (Rapuhia Seamount)
  • To west of Brothers[4]
• Gilianes Seamount −700 metres (−2,297 ft) 34.77°S 178.58°E / -34.77; 178.58 (Gilianes Seamount)
  • To west of Brothers[4]
• Brothers Seamount −1,350 metres (−4,429 ft) 34.875°S 179.075°E / -34.875; 179.075 (Brothers Seamount) [6]
  Main article: Brothers Seamount
• Healy −1,150 metres (−3,773 ft) 35.0°S 178.9°E / -35.0; 178.9 (James Healy Seamount) [6]
  Main article: James Healy Seamount
  • Two calderas in a 15 kilometres (9 mi) elongated complex with the largest caldera being 3 x 4 km
    • This is believed to have been formed in the 1360 ± 75 CE eruption
  • Cotton −980 metres (−3,215 ft) 35.004°S 178.973°E / -35.004; 178.973 (Cotton Seamount) [6]
    • Satellitic cone to Healy at south west end of complex
• The Silents
  • Silent I Seamount[8]
  • Silent II Seamount −850 metres (−2,789 ft) 35.15991°S 178.86805°E / -35.15991; 178.86805 (Silent II Seamount)[7][8]
• The Rumbles
  • Rumble I Seamount −1,100 metres (−3,609 ft) 35.5°S 178.9°E / -35.5; 178.9 (Rumble I) [6]
  • Rumble II West Seamount −1,200 metres (−3,937 ft) 35.353°S 178.527°E / -35.353; 178.527 (Rumble II West Seamount) [6]
  • Rumble II East Seamount −850 metres (−2,789 ft) 35.42916°S 178.65475°E / -35.42916; 178.65475 (Rumble II East Seamount)[7]
  • Rumble III Seamount −140 metres (−459 ft) 35.745°S 178.478°E / -35.745; 178.478 (Rumble III) [6]
    • Largest of the chain of Rumble seamounts
    • Eruptions on:[9]
      • 9 July 1958
      • 16 January 1963
      • 15 October 1973
      • 15 June 1986
      • 2 July 2008
  • Rumble IV Seamount −450 metres (−1,476 ft)36.13°S 178.05°E / -36.13; 178.05 (Rumble IV) [6]
  • Rumble V Seamount −1,100 metres (−3,609 ft)36.139°S 178.197°E / -36.139; 178.197 (Rumble V) [6]
• Lillie Seamount −1,280 metres (−4,199 ft)35.86956°S 178.43546°E / -35.86956; 178.43546 (Lillie Seamount)[7]
  • Lillie is north of Rumbles IV and V
• Tangaroa Seamount −600 metres (−1,969 ft) 36.321°S 178.028°E / -36.321; 178.028 (Tangaroa Seamount) [6]
• Clark Seamount −860 metres (−2,822 ft) 36.446°S 177.839°E / -36.446; 177.839 (Clark Seamount) [6]
  Main article: Clark Seamount
• Whakatāne Seamount −900 metres (−2,953 ft) 36.78282°S 177.46181°E / -36.78282; 177.46181 (Whakatāne Seamount)[7][4]
  Main article: Whakatāne Seamount

References