South Kermadec Ridge Seamounts
The South Kermadec Ridge Seamounts are a continuation of the volcanic island arc, formed at the convergent boundary where the Pacific Plate subducts under the Indo-Australian Plate. The subducting Pacific Plate created the Kermadec Trench, the second deepest submarine trench, 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.
This area of the Kermadec Arc - Havre Trough is a relatively young oceanic arc-back-arc system as it became active in the Quaternary. The seamounts include:
- Speight Knoll
- Oliver Knoll
- Haungaroa Seamount
- Kuiwai Seamount
- Cole Seamount
- Ngātoroirangi Seamount
- Sonne Seamount
- Kibblewhite Seamount
- Gill Seamount
- *Situated in the middle of a deep basin in the Havre Trough, to the west of Kibblewhite and actually closer to the Lau-Colville Ridge than the Kermadec Ridge
- *Basalt age 1.1 ± 0.4 Ma
- Yokosuka Seamount
- *To west of Brothers situated on an elevated basal plateau
- Rapuhia Seamount
- *To west of Brothers
- Gilianes Seamount
- *To west of Brothers
- Brothers Seamount
- [James James Healy Seamount|Healy Seamount|Healy]
- * Two calderas in a 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
- **Satellitic cone to Healy at south west end of complex
- The Silents
- * Silent I Seamount
- * Silent II Seamount
- The Rumbles
- * Rumble I Seamount
- * Rumble II West Seamount
- * Rumble II East Seamount
- * Rumble III Seamount
- ** Largest of the chain of Rumble seamounts
- **Eruptions on:
- ***9 July 1958
- ***16 January 1963
- ***15 October 1973
- ***15 June 1986
- ***2 July 2008
- * Rumble IV Seamount
- * Rumble V Seamount
- Lillie Seamount
- *Lillie is north of Rumbles IV and V
- Tangaroa Seamount
- Clark Seamount
- Whakatāne Seamount