Since hot rocks are in a more expanded state and then contract as they cool (as they spread away from the ridge), the midocean ridges stand up high above the surrounding seafloor. The seafloor depth increases with distance away from the midocean ridges.
Table of Contents
What feature of the ocean floor develops where the oceanic lithosphere bends downward and sinks into the mantle?
Where two tectonic plates converge, if one or both of the plates is oceanic lithosphere, a subduction zone will form. An oceanic plate will sink back into the mantle. Remember, oceanic plates are formed from mantle material at midocean ridges.
What physiographic feature of the ocean floor lies at the base of the continental slope?
Abyssal plains Continuing your journey across the ocean basin, you would descend the steep continental slope to the abyssal plain. At depths of over 10,000 feet and covering 70% of the ocean floor, abyssal plains are the largest habitat on earth.
Why are mid ocean ridges elevated quizlet?
The Mid-Oceanic Ridge is elevated above surrounding seafloor because it is made of hotter and less dense lithosphere than oceanic crust farther away from the divergent boundary.
What happens at mid-ocean ridges?
Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.
How deep are deep sea trenches?
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 the source of energy for the life in deep ocean trenches where sunlight does not reach?
ANSWER. No sunlight reaches the deep ocean trenches and they get all of their energy from chemicals dissolved in the water.
What characteristic of a slab of oceanic lithosphere leads to the formation of deep ocean trenches instead of shallow trenches?
What characteristic of a slab of oceanic lithosphere leads to the formation of deep-ocean trenches instead of shallow trenches? Depends largely on its age and therefore its density (older = more dense) which results in a higher angle of subduction. Briefly describe how mountain belts such as the Himalayas form.
Which type of zone is located at a deep ocean trench?
Ocean trenches occupy the deepest layer of the ocean, the hadalpelagic zone. The intense pressure, lack of sunlight, and frigid temperatures of the hadalpelagic zone make ocean trenches some of the most unique habitats on Earth.
What is the most important topographic feature of the ocean floor why?
The important features are the extensive continental shelves less than 250 m deep (pink); the vast deep ocean plains between 4,000 and 6,000 m deep (light and dark blue); the mid-Atlantic ridge, in many areas shallower than 3,000 m; and the deep ocean trench north of Puerto Rico (8,600 m).
What are 4 types of ocean floor?
- Continental Shelf.
- Continental slope.
- Abyssal plains.
- The ocean deeps/ submarine trenches.
What are four features of deep ocean basins?
Geographic features associated with deep-ocean basins include trenches, abyssal plains, ocean ridges and rises, and submarine mountainous regions.
Which is the best description of a mid-ocean ridge?
A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about 2,600 meters (8,500 ft) and rises about 2,000 meters (6,600 ft) above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary.
How are mid-ocean ridges formed at divergent tectonic plates quizlet?
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.
What is the name of the process that occurs at the mid-ocean ridge?
This rock (basalt) becomes a new part of Earth’s crust. Mid-Ocean Ridges Seafloor spreading occurs along mid-ocean ridges—large mountain ranges rising from the ocean floor.
What happens at deep ocean trenches?
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 is the difference between Rift Valley and mid-ocean ridge?
Continental rift zones occur in weak spots in the continental lithospheric plate. A mid-ocean ridge usually originates in a continental plate as a rift zone that expands to the point of splitting the plate apart, with seawater filling in the gap.
What do mid-ocean ridges and hotspots have in common?
The buoyant rise of hot material transports heat to the surface from the deep interior while colder material sinks at subduction zones. Mid-ocean ridges and hotspots are major expressions of heat dissipation at Earth’s surface, as evidenced by their abundant volcanic activity.
Is there a door at the bottom of the Mariana Trench?
Has anything been to the bottom of the Mariana Trench?
Explorer Reaches Bottom of the Mariana Trench, Breaks Record for Deepest Dive Ever. Explorer and businessman Victor Vescovo descended 35,853 feet (10,927 meters) into the Pacific Ocean, breaking the record for deepest dive ever.
What did they find in the Mariana Trench?
A recent study revealed that a plastic bag, like the kind given away at grocery stores, is now the deepest known piece of plastic trash, found at a depth of 10,975 meters (36,000 feet) inside the Mariana Trench.
How can plants grow in the ocean without sunlight?
Obviously, organisms who live at the deep sea vents can’t rely on the Sun; instead, many of them rely on the chemicals that come out of the vents—the process they use to create food is called chemosynthesis instead of photosynthesis.
At what depth is there no light in the ocean?
The aphotic zone exists in depths below 1,000 meters. Sunlight does not penetrate to these depths and the zone is bathed in darkness.
What is the dark part of the ocean called?
Bthypelagic Zone – The next layer is called the bathypelagic zone. It is sometimes referred to as the midnight zone or the dark zone. This zone extends from 1,000 meters (3,281 feet) down to 4,000 meters (13,124 feet). Here the only visible light is that produced by the creatures themselves.
When oceanic lithosphere converges towards continental lithosphere the oceanic lithosphere is subducted under the continental lithosphere because it is?
when oceanic lithosphere collides with continental lithosphere, oceanic subducts because it’s denser than continental lithosphere. when two plates are made of oceanic lithosphere and collide, one plate is subducted under the other, forming deep ocean trench.