How do mid-ocean ridges form and evolve?
How do mid-ocean ridges form and evolve?
The mid-ocean ridge is a continuous range of undersea volcanic mountains that encircles the globe almost entirely underwater. 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.
How does the mid-ocean ridge cause new crust to form?
Mid-ocean ridges are the boundaries between tectonic plates and are the place where the plates spread apart from each other. Magma from the underlying mantle erupts at the edges, then cools and solidifies to form new ocean crust.
Are mid-ocean ridges divergent or convergent?
The mid-ocean ridge system is an example of a divergent (rather than a convergent or transform) plate boundary. The mid-ocean ridge system has been understood only since the development and acceptance of plate tectonic theory in the 1960s.
What material forms the mid-ocean ridges?
Mid-ocean ridges are created by the upwelling of basaltic lava and lateral rifting of ocean crust (Figure 6.12). They form a rift valley system that encircles the Earth along a total length of over 75,000 km (Figure 6.11).
What is an example of mid ocean ridge?
Mid-ocean ridges form where two tectonic plates are pulling apart, also called seafloor spreading. The Mid-Atlantic Ridge, which is spreading one to two inches a year, along with the East Pacific Rise, which is spreading two to six inches a year, are two examples of very long mid-ocean ridges
What is the general age of crust at mid ocean ridges?
200 million years
What is the definition of mid-ocean ridge?
: an elevated region with a central valley on an ocean floor at the boundary between two diverging tectonic plates where new crust forms from upwelling magma.
What do you expect to find at mid-ocean ridge?
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.
What 2 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.
Why is the mid-ocean ridge important?
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.
Does subduction occur at mid-ocean ridges?
New seafloor is generated from the upper mantle at the mid-oceanic ridges, spreads laterally outward, and is eventually subducted, or consumed, at the margins of ocean basins. Subduction may also occur between two regions of oceanic crust, with older, denser sections underthrusting younger, less-dense ones.
What is the difference between Rift Valley and Mid-Ocean Ridge?
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.
What is the relationship between a mid-ocean ridge and a rift valley?
As tectonic plates move away from one another at mid-ocean ridges, molten rock from the mantle may well up and harden as it contacts the frigid sea, forming new oceanic crust at the bottom of the rift valley.
How deep is the Mid Atlantic Ridge?
1.4 km
What is one way that continental rifts are similar to mid-ocean ridges?
Answer: Both mid-ocean ridges and continental rifts form where two plates are moving apart from each other
Which feature of Earth is created at mid-ocean ridges quizlet?
Seafloor spreading 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. Seafloor spreading helps explain continental drift in the theory of plate tectonics.
What did scientists notice when they observed the mid-ocean ridge?
What did scientists in a submersible see when they observed the mid-ocean ridge? They discovered this by finding the age of rock samples obtained by drilling in the ocean floor. A deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle.
What technology did scientists use in the mid 1980s to map the mid-ocean ridge?
Inside Earth – Plate Tectonics retake
| Question | Answer |
|---|---|
| What technology did scientists use in the mid-1900’s to map the mid-ocean ridge? | sonar |
| When you touch a hot pot or pan, energy moves from the pot to your hand. This is called… | heat transfer |
| Earth’s mantle is… | a layer of hot rock. |
What technology did scientists use in the mid 1900s to map the mid-ocean ridge?
sonar
Why are rocks younger at the Mid-Ocean Ridge than they are farther away from it?
The scientists found that the farther the rocks the older the rocks were,so the youngest rocks were found near the mid-ocean ridge. This showed that sea-floor spreading took place because that fact that rocks were because pushed out showed us that the sea-floor was spreading.
Does the oceanic lithosphere get older or younger as you move closer to the mid-ocean ridge?
The oceanic lithosphere thickens as it ages and moves away from the mid-ocean ridge. As a result, the oceanic lithosphere is much younger than the continental lithosphere: the oldest oceanic lithosphere is about 170 million years old, while parts of the continental lithosphere are billions of years old.
What happens to the age of rocks as you move away from ocean ridges?
As rocks crystallise from lava at the ridges, they literally record the magnetic field of the Earth at the time of their creation. The two parts of the oceanic plate are pulled apart, and magnetic stripes become older as they move away from the mid-ocean ridge.
What does seafloor spreading look like?
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor
What is the theory of seafloor spreading?
Seafloor spreading, theory that oceanic crust forms along submarine mountain zones, known collectively as the mid-ocean ridge system, and spreads out laterally away from them. …
What are 3 types of evidence for seafloor 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.
Where is active seafloor spreading occurring today?
Where is active sea floor spreading occurring today? Seafloor spreading is the movement of old rock that is being pushed by the new young oceanic crust. This would be a divergent since the plates are separating from each other. Active seafloor spreading is occurring at mid-ocean ridges.
What is the importance of seafloor spreading?
Today it refers to the processes creating new oceanic lithosphere where plates move apart. Seafloor spreading replaces the lithosphere destroyed by subduction, and exerts important influences on Earth’s chemical and biological evolution.
What are the features of seafloor?
Features of the ocean include the continental shelf, slope, and rise. 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.
Which boundary is seafloor destroyed?
COnvergent Boundary