The Tonga Trench is located in the Pacific ocean and is 32,000 ft (9,900 m) deep.
The trench and its forearc form an active convergent margin between two plates of the lithosphere, the Pacific Plate being subducted into the earth's semi-molten aesthenosphere, and the northeastern corner of the Australian Plate overriding it. The Tonga trench extends north-northeast from the North Island of New Zealand. Categories: Plate tectonics | Sedimentology | Geology stubs ... The lithosphere (from the Greek for rocky sphere) is the solid outermost shell of a rocky planet. ... The Pacific plate is shown in pale yellow on this map The Pacific Plate is an oceanic tectonic plate beneath the Pacific Ocean. ... Categories: Geology stubs | Plate tectonics ... The asthenosphere (from an invented Greek a + sthenos without strength) is the region of the Earth between 100-200 km below the surface—but perhaps extending as deep as 400 km—that is is the weak or soft zone in the upper mantle. ... Categories: Plate tectonics | Geology stubs ... The North Island is one of the two main islands of New Zealand, the other being the South Island. ...
The convergence is taking place at breath-taking speed: a rate estimated at approximately 15 cm/yr (by Lonsdale, 1986); however, recent Global Positioning Satellite measurements indicate in places a convergence of 24 cm/yr across the northern Tonga Trench, which is the fastest plate velocity yet 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 (see the Relics section). A radioisotope thermoelectric generator (RTG) is a simple electrical generator which obtains its power from radioactive decay. ... Apollo 13 was an American space mission, part of the Apollo program. ...
External link
Bathymetral maps in color, with full descriptive notes, as published in Marine Geophysical Researches, 2000. (Wikipedia might obtain one of these maps)
Trenches along with volcanic arcs and zones of earthquakes that dip under the volcanic arc as deeply as 700 km are diagnostic of convergent plate boundaries and their deeper manifestations, subduction zones.
Trenches are centerpieces of the distinctive physiography of a convergent plate margin.
Trenches distant from an influx of continental sediments lack an accretionary prism, and the inner slope of such trenches is commonly composed of igneous or metamorphic rocks.
Feeds |
Contact