Bounty through

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Topographic map of Zealandia with the Bounty Trough to the southeast

The Bounty Trough is a depression east of New Zealand lying below sea level. It is part of the 4.9 million square kilometers and 94% below sea level area that scientists call Zealandia and that is being advertised as a continent .

geography

The Bounty Trough is located around 100 km east of the South Island of New Zealand, between the undersea mountain range Chatham Rise in the north and the also undersea Campbell Plateau in the south. The depression, which is shaped like a former valley with a narrow depression ( bounty channel ) running in the middle in a west-east direction, similar to a river, is around 800 km long, 250 km wide and falls from around 1000 m below sea level to the east to around 4000 m.

Origin of name

At the request of the New Zealand Geographic Board (NZGB) in October 2012, the designation Bounty Trough for the deepening on the sea floor was officially adopted by the ( GEBCO ) Sub-Committee on Undersea Feature Names (SCUFN), a committee established by the Intergovernmental Oceanographic Commission ( of UNESCO ) together with the International Hydrographic Organization . The name Bounty was borrowed from the name of the Bounty Islands , which are located south of the eastern part of the Bounty Trough and were named on September 8, 1788 by Captain William Bligh after his ship Bounty .

For the narrow, river-like depression recognizable on topographic maps, an official name was also set in October 2012 and the channel was designated the Bounty Channel .

geology

It is believed that the Bounty Trough originally a grave breach was that in the late stage of the separation of New Zealand from the supercontinent Gondwana , which began about 125 million years ago and 100 million years lasted, was active and in the Cretaceous one of Subduction zone , which was north of the Chatham Rise . The Bounty Trough drops eastwards in three stages and is divided into basins around 1000 m lower. The basement of the Bounty Trough is covered with stratified sediments that have formed since the Pliocene and are around 2 km thick. The conspicuous Bounty Channel cuts deep into the sediments, shows river characteristics and was probably formed in the last Ice Age.

literature

Individual evidence

  1. ↑ Mortimer et al. 10 co-authors: Zealandia: Earth's Hidden Continent . In: GSA Today . 2017, p.  1 .
  2. ^ Bounty Trough . In: GEBCO - Undersea Feature Names Gazetteer . National Centers for Environmental Information (NOAA), accessed on March 12, 2017 (English, interactive map for selecting the geographic object).
  3. ↑ Coordinates and longitudes of the Campbell Plateau were determined by Google Earth .
  4. ↑ a b 25th SCUFN Meeting - Report . (PDF; 1.9 MB) International Hydrographic Organization , January 2012, accessed on March 12, 2017 (English).
  5. ^ The History of Zealandia . GNS Science , accessed March 12, 2017 .
  6. ↑ Grobys, Gohl, Davy , Uenzelmann-Neben , Deen, Barker : Is the Bounty Trough off eastern New Zealand an aborted rift? . 2007, p.  18-20 .
  7. ↑ Grobys, Gohl, Davy , Uenzelmann-Neben , Deen, Barker : Is the Bounty Trough off eastern New Zealand an aborted rift? . 2007, p.  1-3 .
  8. ^ Keith Lewis, Scott D. Nodder, Lionel Carter : Sea floor geology - Abysses . In: Alexander Hare McLintock (Ed.): An Encyclopaedia of New Zealand . Wellington 1966 ( online [accessed March 12, 2017]).

Coordinates: 44 ° 30 ′ 0 ″  S , 172 ° 0 ′ 0 ″  E