Why do mid-ocean ridges spread at different rates?
As the plates separate molten rock rises to the seafloor producing enormous volcanic eruptions of basalt. The speed of spreading affects the shape of a ridge – slower spreading rates result in steep irregular topography while faster spreading rates produce much wider profiles and more gentle slopes.
What is the evidence of spreading at mid-ocean ridges?
The magnetic history of the earth is thus recorded in the spreading ocean floors as in a very slow magnetic tape recording forming a continuous record of the movement of the ocean floors. Other supportive evidence has emerged from study of the fracture zones that offset the sections of the ridge.
What two features occur at mid-ocean ridges?
There are two processes ridge-push and slab-pull thought to be responsible for the spreading seen at mid-ocean ridges and there is some uncertainty as to which is dominant. Ridge-push occurs when the weight of the ridge pushes the rest of the tectonic plate away from the ridge often towards a subduction zone.
Which increases relative to the mid-ocean ridge?
Increased seafloor spreading means that the mid-ocean ridge will then expand and form a broader ridge with decreased average depth taking up more space in the ocean basin. This displaces the overlying ocean and causes sea levels to rise.
How can you differentiate slow spreading ridges and fast spreading ridges?
Fast-spreading mid-ocean ridges have an axial high (the “rise crest”) whereas slow-spreading ridges have deep axial rift valleys. This difference in morphology is reflected in the ruggedness of the flanks of ridges.
What is the rate of spreading at the Mid Atlantic Ridge is this considered fast or slow?
The Mid-Atlantic Ridge for instance is a slow spreading center. It spreads 2-5 centimeters (.8-2 inches) every year and forms an ocean trench about the size of the Grand Canyon. The East Pacific Rise on the other hand is a fast spreading center.
What are three kinds of evidence of the ocean floor spreading?
Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material magnetic stripes and drilling samples.
How seafloor spreading occurs in the mid-ocean ridge and the formation of the new oceanic crust?
What are the evidence of seafloor spreading theory?
Evidence of Sea Floor Spreading. Harry Hess’s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. This evidence was from the investigations of the molten material seafloor drilling radiometric age dating and fossil ages and the magnetic stripes.
What occurs at the mid-ocean ridge during the process?
Answer: 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.
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.
What is the major evidence that sea floor spreading creates new lithosphere explain your answer?
The record of magnetic reversals is carried away from each side of the spreading center of a mid-ocean ridge showing that the molten rock is creating new lithosphere.
How does the rate of seafloor spreading affect sea level?
The increased rate of seafloor spreading caused sea level to rise. Increasing the rate of seafloor spreading inflates the ridge. Hot young lithosphere is forming and moving away from the ridge at a faster rate and moves a greater distance from the ridge before it cools and contracts. … So sea level rises.
What contributes to the high thermal energy flow readings near the center of a mid-ocean ridge?
The high thermal-energy flow at a mid-ocean ridge comes from seawater. 9. Magnetic bands on the ocean floor are evidence that Earth’s magnetic field changes.
What type of tectonic plate boundary created the Mid Atlantic Ridge?
The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean and part of the longest mountain range in the world.
Which mid ocean ridge is spreading the slowest?
The Ridge is named after him and the name was recognized in April 1987 by SCUFN (under that body’s old name the Sub-Committee on Geographical Names and Nomenclature of Ocean Bottom Features). The ridge is the slowest known spreading ridge on earth with a rate of less than one centimeter per year.
Which mid ocean ridge is spreading the fastest?
The fastest present-day seafloor spreading ~150 km/Myr occurs along the Pacific-Nazca boundary between the Easter and Juan Fernandez microplates.
What is the difference between mid ocean ridges and rift valleys?
The major difference between different types is what type of plate the divergent boundary is between. If the boundary is found between two continental plates you are left with a rift valley. … If two oceanic plates begin moving away from each other it creates a mid-oceanic ridge.
Which is spreading faster the Mid-Atlantic Ridge or the East Pacific Rise?
The East Pacific Rise is spreading faster than the Mid-Atlantic Ridge. The wide swath of red and orange parallel to the East Pacific Rise illustrates that a large area of oceanic rocks are very young.
Where is the spreading ridge?
Which ridge is spreading faster?
What is the process by which new oceanic lithosphere forms at mid-ocean ridge called?
How are mid-ocean ridges formed?
It formed and evolves as a result of spreading in Earth’s lithosphere—the crust and upper mantle—at the divergent boundaries between tectonic plates. The vast majority of volcanic activity on the planet occurs along the mid-ocean ridge and it is the place where the crust of the Earth is born.
What does the seafloor spreading do for tectonic plates?
What evidence helped give strong support for the hypothesis of seafloor spreading at mid-ocean ridges?
This hypothesis was supported by several lines of evidence: (1) at or near the crest of the ridge the rocks are very young and they become progressively older away from the ridge crest (2) the youngest rocks at the ridge crest always have present-day (normal) polarity and (3) stripes of rock parallel to the ridge …
What is evidence of seafloor spreading Brainly?
One piece of evidence of seafloor spreading is a mid-ocean ridge. Explanation: The Mid-Atlantic Ridge is a mountain system formed by plate tectonics on the seafloor.
What parts of your model represent the Mid-Ocean Ridge?
Where did the geologist discovered mid-ocean ridge?
It is now called the Mid-Ocean Ridge. In 1953 American physicists Maurice Ewing (1906-1974) and Bruce Heezen (1924-1977) discovered that through this underwater mountain range ran a deep canyon. In some places the canyon called the Great Global Rift came very close to land.
What is the average spreading rate along the mid Atlantic and the Mid Indian ridges?
Mid-ocean ridges are geologically important because they occur along the kind of plate boundary where new ocean floor is created as the plates spread apart. 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.
Which ocean is spread by plate tectonics?
the Pacific Ocean
Seafloor-spreading rates are much more rapid in the Pacific Ocean than in the Atlantic and Indian oceans. At spreading rates of about 15 cm (6 inches) per year the entire crust beneath the Pacific Ocean (about 15 000 km [9 300 miles] wide) could be produced in 100 million years.
Why are mid-ocean ridges elevated compared to the surrounding ocean floor?
How does the oceanic lithosphere change as it moves away from the mid-ocean ridge?
The oceanic lithosphere thickens as it ages and moves away from the mid-ocean ridge. This thickening occurs by conductive cooling which converts hot asthenosphere into the lithospheric mantle and causes the oceanic lithosphere to become increasingly dense with age.
Is new oceanic lithosphere is unable to form at mid-ocean ridges?
New oceanic lithosphere is unable to form at mid-ocean ridges. … Bands of magnetic material in the sea floor that have opposite poles or exhibit magnetic reversal can provide evidence for sea floor spreading.
What is the role of mid-ocean ridge in the movement of lithospheric plates?
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.
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