Trenches are long, narrow depressions on the seafloor that form at the boundary of tectonic plates where one plate is pushed, or subducts, beneath another.
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What is an example of a trench?
For example, the Mariana Trench, which lies beneath the Pacific Ocean near the Mariana island chain and not far from the coast of Japan, is the product of what’s called “subduction.” Beneath the trench, the Eurasian plate is sliding over a smaller one called the Philippine Plate, which is sinking into the mantle and
What do you mean trenches?
Definition of trench
(Entry 1 of 2) 1a : a long cut in the ground : ditch especially : one used for military defense often with the excavated dirt thrown up in front.
What is deep sea trench in science?
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.
What is trench in earthquake?
An oceanic trench is a linear depression of the sea floor caused by the subduction of one plate under another.
Is a trench a hole?
A trench is a type of excavation or in the ground that is generally deeper than it is wide (as opposed to a wider gully, or ditch), and narrow compared with its length (as opposed to a simple hole or pit).
Where are trenches found?
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.
How is a trench made?
In particular, ocean trenches are a feature of convergent plate boundaries, where two or more tectonic plates meet. At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.
Why are trenches full of water?
Much of the land where the trenches were dug was either clay or sand. The water could not pass through the clay and because the sand was on top, the trenches became waterlogged when it rained. The trenches were hard to dig and kept on collapsing in the waterlogged sand.
What is a trench for carrying water?
Infiltration trenches are gravel-filled and designed to receive stormwater. A trench can take water from a downpipe, overflow from tanks, or from pipes draining hard surfaces such as driveways or paving. Trenches are lined in non- woven geotextile and filled with gravel (such as scoria).
How many trenches are in the ocean?
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.
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.
Where is the deepest trench in the world?
the Pacific Ocean
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. Scientists use a variety of technologies to overcome the challenges of deep-sea exploration and explore the Trench.
Are trenches faults?
Normal faults, found on the outer rise of many Pacific trenches (e.g., Masson 1991), are one type of small-scale feature with potential impacts on the upper plate morphology. As the plate enters a subduction zone, flexural bending of the plate produces the outer rise (e.g., Bodine et al.
What is the deep ocean called?
The deepest part of the ocean is called the Challenger Deep and is located beneath the western Pacific Ocean in the southern end of the Mariana Trench, which runs several hundred kilometers southwest of the U.S. territorial island of Guam.
What is fault line and trenches?
What’s the difference between a trench and a fault line? A. A trench is created where one tectonic plate subducts under another tectonic plate. A fault line is a crack in the upper layer of the Earth’s crust. This fault is caused by stress caused by the tectonic plate movements.
How many feet is a trench?
The Mariana Trench is 6033.5 fathoms deep. Knowing that it is (11,033 meters (36,201 feet) deep, how do do we perform the conversion to fathoms?
What are trenches used for?
Trenches provided relative protection against increasingly lethal weaponry. Soldiers dug in to defend themselves against shrapnel and bullets. On the Western Front, trenches began as simple ditches and evolved into complex networks stretching over 250 miles (402 kilometres) through France and Belgium.
When a trench is 4 feet or more in depth?
A stairway, ladder, ramp or other safe means of egress shall be located in trench excavations that are 4 feet (1.22 m) or more in depth so as to require no more than 25 feet (7.62 m) of lateral travel for employees.
How are trenches formed kids?
As the plates move, one plate may go under another. This is called a subduction zone. Where two plates meet at a subduction zone, there is usually an extremely deep ocean trench. A trench happens when one tectonic plate goes under another in a subduction zone.
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.