Seabed mining has potential as Tonga's EEZ covers the world's second deepest water, known as the
Tonga Trench, between the Pacific and the Australian tectonic plates; the chain of islands and the two parallel submarine ridges that run along the trench are partly volcanic.
The Tonga Archipelago stretches 250 kilometers along the western margin of the
Tonga Trench in the southern Pacific Ocean.
In back-arc basins, which are widespread in the western Pacific Ocean, a spreading center is located right next to a subduction zone (in this case, the
Tonga Trench) where one plate of Earth's crust dips beneath another one.
The green region here marks the slab of old oceanic plate plunging back into the mantle at the
Tonga Trench in the South Pacific Ocean.
By contrast, the Pacific plate is thought to be mature and tough where it reaches the
Tonga trench.
Fortunately, the plutonium container survived re-entry and, according to NASA documents, was "successfully targeted to deposit intact in the
Tonga Trench in the South Pacific where it is effectively isolated from man's environment." It remains there to this day.
The extraordinary scene was captured along the
Tonga Trench during a research expedition last summer, which was the result of a joint project by the universities of Oxford and Durham, funded by the Natural Environment Research Council.
The Philippine Trench, the third deepest part of the world after the Mariana and the
Tonga trenches, has been mentioned in the opening sequence of Warner Bros.