Tonga Trench

The Tonga Trench is located in the Pacific Ocean and is 10,882 meters (35,702 ft) deep at its deepest point, known as the Horizon Deep.

The trench lies at the northern end of the Kermadec-Tonga Subduction Zone, an active subduction zone where the Pacific Plate is being subducted below the Tonga Plate and the Indo-Australian Plate. The Tonga Trench extends north-northeast from the Kermadec Islands north of the North Island of New Zealand. The trench turns west north of the Tonga Plate and becomes a transform fault zone.

The convergence is taking place at a rate estimated at approximately 15 centimeters (6 in) per year (by Lonsdale, 1986); however, recent Global Positioning Satellite measurements indicate in places a convergence of 24 centimeters (10 in) per year across the northern Tonga Trench, which is the fastest plate velocity recorded on the planet (Bevis "et al.", 1995).Such oceanic trenches are important sites for the formation of what will become continental crust and for recycling of material back into the mantle. Along the Tonga Trench mantle-derived melts are transferred to the island arc systems, and abyssal oceanic sediments and fragments of oceanic crust are collected.

The trench is the last resting place of the Radioisotope thermoelectric generator from the aborted Apollo 13 mission.

References

*Wright, Dawn J., et al., 2001, [http://dusk.geo.orst.edu/tonga/ Bathymetry of the Tonga Trench and Forearc: A Map Series, as published in "Marine Geophysical Researches", 2000.] [http://dusk2.geo.orst.edu/tonga/tonga_series.pdf PDF version]
*Bird, P., An updated digital model of plate boundaries, Geochem. Geophys. Geosyst., 4(3), 1027, doi:10.1029/2001GC000252, 2003. [http://element.ess.ucla.edu/publications/2003_PB2002/2003_PB2002.htm] also available as a PDF file (13 mb) [http://element.ess.ucla.edu/publications/2003_PB2002/2001GC000252.pdf]

See also

*Oceanic trench