Ocean trenches are
deep sections of the ocean where an oceanic plate is usually sinking below a continental plate
. … They are formed in the subduction zone as the denser oceanic plate is subjected under the continental plate.
What is a deep-ocean trench in science?
Ocean trenches are long, narrow depressions on the seafloor. These chasms are
the deepest parts of the ocean
—and some of the deepest natural spots on Earth. … At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.
Where are deep-ocean trenches found quizlet?
What are deep-ocean trenches? Long, narrow creases in the seafloor representing the deepest parts of the ocean floor. Most are located
along the margins of the Pacific Ocean, with only two being located in the Atlantic
.
How is a deep-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.
What are some deep-ocean trenches?
- Mariana Trench. Located in the western Pacific Ocean, the Marina Trench is considered to be the deepest part of the Earth’s surface. …
- Tonga Trench. …
- Philippine Trench. …
- Kuril- Kamchatka Trench. …
- Kermadec Trench. …
- Izu-Ogasawara Trench. …
- Japan Trench. …
- Puerto Rico Trench.
What is the deepest trench in the 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.
Why are most trenches found in the Pacific Ocean?
Why are most oceanic trenches found in the Pacific Ocean?
The Pacific Ocean is shrinking and plates are descending below surrounding plates along its edges
, hence the creation of trenches.
Why are deep sea trenches important?
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They also are
the deepest parts of the ocean floor
. Trenches define one of the most important natural boundaries on the Earth’s solid surface, that between two lithospheric plates.
What do deep sea trenches reveal about Earth’s crust quizlet?
What do deep-sea trenches reveal about Earth’s crust? They
indicate where crust is moving together and diving down deeper into the mantle.
What are the three deepest trenches in the world?
| Trench Ocean Maximum Depth | Mariana Trench Pacific Ocean 10,920 m (35,830 ft) | Tonga Trench Pacific Ocean 10,820 m (35,500 ft) | Philippine Trench Pacific Ocean 10,540 m (34,580 ft) | Kuril–Kamchatka Trench Pacific Ocean 10,542 m (34,587 ft) |
|---|
How are deep-ocean trenches formed quizlet?
Ocean trenches are deep sections of the ocean where an oceanic plate is usually sinking below a continental plate. … They are formed in the
subduction zone as the denser oceanic plate is subjected under the continental plate
.
What are the four layers of oceanic crust from top to bottom?
The Oceanic crust is the uppermost layer of the oceanic portion of a tectonic plate. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of
troctolite, gabbro and ultramafic cumulates
. The crust overlies the solidified and uppermost layer of the mantle.
Where are the deepest parts of the seafloor?
The average ocean depth is 2.3 miles .
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.
How many deep-ocean trenches are there?
Of the Earth’s
20 major
trenches, 17 are found in the Pacific basin, a vast area rimmed by trenches of both marginal and island arc varieties. Marginal trenches bound the west coast of Central and South America from the Gulf of California to southern Chile.
Are deep-ocean trenches geologically stable?
They are
not geologically very stable
because volcanic activity and earthquakes are always associated with deep-ocean trenches.
What happens when oceanic crust falls into deep-ocean trenches?
The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary. … As
subduction
occurs, crust closer to a mid-ocean ridge moves away from the ridge and toward a deep-ocean trench. Sea-floor spreading and subduction work together.
