its a large crack in the ground, usually in a "V" shape, where the tectonic plate have seperated, leaving a large gap in the ground
Undersea volcanoes that erupt.
The Trieste was that famous submarine. It is actually considered a bathyscaphe, but the term submarine could be applied. It dove to the deepest undersea point in the world, the Challenger Deep in the Mariana Trench, where the water depth is nearly 36,000 feet. A link is provided to the Wikipedia article on this revolutionary undersea vehicle.
Undersea Fleet was created in 1956.
Undersea City was created in 1958.
Undersea Trilogy was created in 1992.
Undersea Quest was created in 1954.
The duration of Undersea Kingdom is 3.77 hours.
Undersea Trilogy has 501 pages.
Some islands may be built by undersea volcanoes.
Naval Undersea Museum was created in 1995.
Undersea Kingdom was created on 1936-05-30.
Jules' Undersea Lodge was created in 1986.