deep-sea trench, also called oceanic trench, any long, narrow, steep-sided depression in the ocean bottom in which occur the maximum oceanic depths, approximately 7,300 to more than 11,000 metres (24,000 to 36,000 feet). They typically form in locations where one tectonic plate subducts under another.
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What are the 5 ocean trenches?
The Five Deeps Expedition was the first to reach the deepest point in each of the Earth’s five oceans: the Puerto Rico Trench in the Atlantic, South Sandwich Trench in the Southern Ocean, Java Trench in the Indian Ocean, Challenger Deep in the Pacific and Molloy Deep in the Arctic.
What are three ocean trenches?
The Mariana Trench of the Pacific Ocean, Molly Deep of the Arctic Ocean, Puerto Rico Trench of the Atlantic Ocean, South Sandwich Trench of the Southern Ocean, and the Diamantina Trench of the Indian Ocean are the deepest parts of oceans.
What are the two ocean trenches?
The Pacific Plate is subducting beneath the Mariana Plate forming Mariana Trench. The Pacific Plate is older and colder than the Mariana Plate. The trench formed by these two oceanic plates is the deepest spot in the world’s oceans and includes the Challenger Deep.
What is ocean trenches and ridges?
Trench: very deep, elongated cavity bordering a continent or an island arc; it forms when one tectonic plate slides beneath another. Ridge: underwater mountain range that criss-crosses the oceans and is formed by rising magma in a zone where two plates are moving apart.
What is the name of the deepest ocean trench?
The Mariana Trench
The Mariana Trench, in the Pacific Ocean, is the deepest location on Earth. According to the Exclusive Economic Zone (EEZ), the United States has jurisdiction over the trench and its resources.
What is the deepest zone of the ocean called?
hadalpelagic zone
The deepest zone of the ocean, the hadalpelagic zone extends from 19,700 feet (6,000 meters) to the very bottom at 36,070 feet (10,994 meters) in the Mariana Trench off the coast of Japan.
Where are deep sea trenches?
Deep-sea trenches generally lie seaward of and parallel to adjacent island arcs or mountain ranges of the continental margins. They are closely associated with and found in subduction zones—that is, locations where a lithospheric plate bearing oceanic crust slides down into the upper mantle under the force of gravity.
Where are trenches in the ocean?
Trenches are found on the floor of the sea; however, their common name is deep ocean trenches because they are more often found in the deepest areas of the ocean. Trenches are formed in subduction zones where tectonic plates collide. There are many known trenches that scientists continue to study.
How many trenches are in the world?
Globally, there are over 50 major ocean trenches covering an area of 1.9 million km2 or about 0.5% of the oceans. Trenches are geomorphologically distinct from troughs. Troughs are elongated depressions of the sea floor with steep sides and flat bottoms, while trenches are characterized by a V-shaped profile.
What do we call the ridge of the trench?
Firestep. What do we call the ridge of the trench? Parapet.
What is the difference between ocean ridges and ocean trenches?
Ocean ridges are boundaries where plates are being created, whereas trenches are boundaries where plates are being destroyed (subducted).
Are mid ocean ridges and trenches the same?
A mid ocean ridge is a divergent boundary where plates are moving apart, An ocean trench is a convergent boundary where plates are moving together.
Why is it called Mariana Trench?
The Mariana Trench was first pinpointed in 1875 during the undertaking of a global circumnavigation. It was found by utilizing sounding equipment on the HMS Challenger. It was named for the nearby Mariana Islands.
Which ocean is coldest?
The Arctic Ocean
The Arctic Ocean | National Geographic Society.
What’s in the bottom of the ocean?
In addition to minerals, we’ve found unusual animals at the bottom of the ocean. Smithsonian points out that even at 13,000 feet below the surface, where temperatures are near freezing and there’s no sunlight, researchers have discovered living creatures such as fish, coral, crustaceans, jellyfish and worms.
What are the 7 layers of the ocean?
The sunlight zone, the twilight zone, the midnight zone, the abyss and the trenches.
- Sunlight Zone. This zone extends from the surface down to about 700 feet.
- Twilight Zone. This zone extends from 700 feet down to about 3,280 feet.
- The Midnight Zone.
- The Abyssal Zone.
- The Trenches.
What are the 3 levels of the ocean?
There are three main ‘layers’ to the ocean that we will focus on: the surface ocean, the deep ocean, and the seafloor sediments (sediments that are still in contact with seawater).
What are the levels of the ocean called?
The sunlight zone, twilight zone, and deep ocean are the three major zones of the ocean. The deep ocean is further divided into 3 layers which are the midnight zone, the abyss and the trenches.
What causes an ocean trench?
Trenches are formed by subduction, a geophysical process in which two or more of Earth’s tectonic plates converge and the older, denser plate is pushed beneath the lighter plate and deep into the mantle, causing the seafloor and outermost crust (the lithosphere) to bend and form a steep, V-shaped depression.
Which is deeper the ocean or the sea?
Generally, the ocean is much deeper than the sea even if some seas can be almost as deep as big oceans. To give you a few examples, the depth of the Channel is 174m, the one of the North Sea is 700m and for the Black Sea it is 2,212m.