Last Updated on September 26, 2022 by amin
Ocean Basins (Part 2): Features of the Ocean Floor (Deep Ocean Basins)
What is the role of the mid-ocean ridge?
Mid-ocean ridges are the longest largest and most voluminous magmatic environment on Earth. Ridges are the site of new lithospheric and crustal production that may be subsequently subducted into the mantle and recycled or involved in magma-producing dehydration reactions that slowly build up continental crust (Fig.
What type of feature is found at the sea floor spreading centers?
Seafloor spreading occurs along mid-ocean ridges—large mountain ranges rising from the ocean floor. The Mid-Atlantic Ridge for instance separates the North American plate from the Eurasian plate and the South American plate from the African plate.Jun 8 2015See also how does specific heat of water affect climate
What is a crack in the center of a mid-ocean ridge?
Running along the top of this chain of mountains is a deep crack called a rift valley. It is here that new ocean floor is continuously created. As the two sides of the mountain move away from each other magma wells up from the Earth’s interior.
How did the geologists discover that oceanic crust moves beneath the continental crust?
Geologists collect samples of oceanic crust through drilling at the ocean floor using submersibles and studying ophiolites. Ophiolites are sections of oceanic crust that have been forced above sea level through tectonic activity sometimes emerging as dikes in continental crust.
What is the bottom of the sea called?
seabedThe seabed (also known as the seafloor sea floor ocean floor and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as ‘seabeds’.
Why does the oceanic crust sink beneath the continental crust at the subduction zone?
Oceanic crust is denser than continental crust that is why the former sinks through the process of subduction.
Which feature of the ocean floor includes its deepest parts?
The deepest parts of the ocean are within the subduction trenches and the deepest of these is the Marianas Trench in the southwestern Pacific (near Guam) at 11 000 m (Figure 18.5).
What is underneath the ocean floor?
The ocean floor is called the abyssal plain. Below the ocean floor there are a few small deeper areas called ocean trenches. Features rising up from the ocean floor include seamounts volcanic islands and the mid-oceanic ridges and rises.
What feature is generated along spreading centers?
Spreading centers occur where two plates are moving away from each other and deep cracks are opened through the crust. This lengthening of the crust allows magma from the upper mantle to rise to the surface and cool commonly forming basalt. An excellent example is the Mid-Atlantic Ridge.
Ocean Floor Features
What feature of the ocean floor develops?
As plates converge one plate may move under the other causing earthquakes forming volcanoes or creating deep ocean trenches. Where plates diverge from each other molten magma flows upward between the plates forming mid-ocean ridges underwater volcanoes hydrothermal vents and new ocean floor crust.
What is formed when the ocean floor moves on either side of a mid-ocean ridge?
Seafloor spreading or Seafloor spread is a process that occurs at mid-ocean ridges where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
Ocean Floor Features
Do mid-ocean ridges move?
Thus the mid-ocean ridge is also known as a “spreading center” or a “divergent plate boundary.” The plates spread apart at rates of 1 cm to 20 cm per year. As oceanic plates move apart rock melts and wells up from tens of kilometers deep.
Which ocean floor features makes up the deepest parts of the ocean?
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.
What happens to the part of the oceanic crust as it reaches the asthenosphere?
When the oceanic plate is subducted due to partial melting of the asthenosphere magma with an andesitic composition is formed. The magma formed is less dense than the surrounding material so it rises to the surface to form a magmatic arc on the edge of the continent which the oceanic plate is subducted under.
What are the characteristics of mid-ocean ridges?
A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of ~ 2 600 meters (8 500 ft) and rises about two kilometers above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary. See also what language did the romans write in
Which feature is formed near the divergent boundaries between two plates of oceanic crust?
oceanic spreading ridgesMost divergent plate boundaries are underwater and form submarine mountain ranges called oceanic spreading ridges. While the process of forming these mountain ranges is volcanic volcanoes and earthquakes along oceanic spreading ridges are not as violent as they are at convergent plate boundaries.
The Ocean Floor Revealed
What is a spreading center on land called?
The first sort of plate boundary is called a divergent boundary or spreading center. At these boundaries two plates move away from one another.
What is the center of tectonic plates?
Two main tectonic structures are spreading centers and subduction zones. Spreading centers occur at the boundary between two plates that are moving apart called divergent plate boundaries. Here the plate motion opens a gap between the plates and magma from the mantle rises up through it.
What do the slits stand for what does the space under the paper stand for?
What does the space under the paper stand for? The side slits stand for where subduction has occurred and the ocean floor has sunk in. Also the space under the paper stands for the oceanic crust of the Earth.
What Feature Of The Ocean Floor Does The Center Slit Represent??
The center slit represents a Mid-Ocean Ridge 2. The strips of paper represent oceanic crust or seafloor.
What major ocean floor feature was discovered by oceanographers following ww2?
Harry Hess was a geologist and Navy submarine commander during World War II. Part of his mission had been to study the deepest parts of the ocean floor. In 1946 he had discovered that hundreds of flat-topped mountains perhaps sunken islands shape the Pacific floor.
What are the key surface features produced by sea floor spreading?
Midocean ridges transform faults and fracture zones are the key surface features produced by seafloor spreading. In detail midocean ridges are made up of short offset segments. The curved linear features running perpendicular to midocean ridges are fracture zones and transform faults.
What type of boundary would be found at spreading centers?
Divergent boundaries. Divergent boundaries occur along spreading centers where plates are moving apart and new crust is created by magma pushing up from the mantle.Sep 15 2014
Where is the ocean floor deepest?
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 geologic feature is produced by the divergence of the Eurasian Plate and North American Plate?
The Mid Atlantic Ridge
The Mid Atlantic Ridge like other ocean ridge systems has developed as a consequence of the divergent motion between the Eurasian and North American and African and South American Plates.See also where is spain on the world map
What process is involved when the oceanic crust plunges down into the mantle?
This process called subduction occurs at the oceanic trenches (figure 6). The entire region is known as a subduction zone. Subduction zones have a lot of intense earthquakes and volcanic eruptions. The subducting plate causes melting in the mantle.
Why does ocean crust far from a mid-ocean ridge subside?
As the sheets of oceanic crust move away from the mid-ocean ridge the rock is cooled and thus becomes heavier. After about 200 million years the cooled lithospheric plate has become heavier than the asthenosphere that it rides over and it sinks thereby producing a subduction zone.
What is the primary reason for the elevated position of the oceanic ridge system?
The primary reason for the elevated position of the ridge system is that newly created oceanic lithosphere is hot and therefore less dense than cooler rocks of the deep-ocean basin.
What is the meaning of ocean floor?
Definition of seafloor : the floor of a sea or ocean : seabed The Earth’s crust in this view is divided into several immense plates that make up the continents and seafloors and that all float on a hot plastic subterranean “mantle.”— Walter Sullivan.
Why were magnetic patterns found on the ocean floor puzzling?
Why were magnetic patterns found on the ocean floor puzzling? … No rocks were magnetic. They did not show alternating bands of normal and reversed polarity.
Which is the best description of a mid-ocean ridge?
A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range formed by plate tectonics. This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.
Which of the following are not features associated with mid-ocean ridges?
(a)Mid-ocean ridge is not associated with a convergent plate boundary. Explanation: Mid-ocean ridges form near divergent plate boundaries where the new ocean bottom is formed when tectonic plates separate. The Molten rock rises to the seafloor as the plates separate resulting in massive basalt volcanic eruptions.
Why is the center of the Atlantic Ocean shallower than areas closer to the continents?
Question: Why is the center of the Atlantic Ocean shallower than areas closer to the continents? … Oceanic plates collide at this location making submarine mountains c. Newly formed crust at this location is much hotter than older crust d.
What do you call to the middle slit where a new ocean floor is formed?
Mid-ocean ridges occur along divergent plate boundaries where new ocean floor is created as the Earth’s tectonic plates spread apart.