Puysegur Trench

The Puysegur Trench and Macquarie Ridge are marked by the line extending south from the southwestern South Island.

The 6,300-metre (20,700 ft) deep[1] Puysegur Trench is a deep cleft in the floor of the south Tasman Sea formed by the subduction of the Indo-Australian Plate under the Pacific Plate to the south of New Zealand. Immediately to its east lies the Puysegur Ridge, a northern extension of the Macquarie Ridge, which separates the Puysegur Trench from the Solander Trough. To the west is the expanse of the Tasman Basin, which stretches most of the distance to Australia. To the north of the trench lies the Fiordland Basin, which can be considered an extension of the trench. The Puysegur Trench mirrors the Kermadec Trench and Tonga Trench north of New Zealand.

Map
Map of Puysegur Trench (blue) and its active ocean floor tectonic relationships. The immediate adjacent to the south McDougall Fault Zone (red shading) and approximate Macquarie Ridge line (yellow) are shown. The arc Solander volcanic edifice (brown) and the Resolution Ridge (black line) are shown. The Macquarie Ridge associated basins (northwest portion of South East Tasman Basin, Solander Trough & Emerald Basin) are shown in light purple shading as this delimits most of the historic cross faulting and other fault zones closely related to the historic sea floor spreading centre of the Macquarie Ridge (click on map to enable mouse over, a purple dot shown then is the location of the Macquarie Triple Junction far to the south).

The Puysegur Trench stretches for over 800 kilometres south from the southwesternmost point of the South Island's coast, its southernmost extent being 400 kilometres due west of the Auckland Islands. It is named after Puysegur Point.

  1. ^ Stern, Robert J. (2004). Subduction initiation: spontaneous and induced, Earth and Planetary Science Letters 226, 275–292. doi:10.1016/j.epsl.2004.08.007.