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. Eventually, the crust cracks.
How does seafloor spreading occur and where does it occur?
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.
How seafloor spreading occurs in the mid ocean ridge and the formation of the new oceanic crust?
At mid-ocean ridges,
tectonic plates move apart and seafloor
spreading occurs. … It then cools and solidifies in the center of the ridge. The rising magma pushes up between the plates and drives them further apart. As new crust is forming at the spreading center, it pushes the older crust apart.
Where does seafloor spreading occur quizlet?
Where does seafloor spreading occur? This process occurs along divergent plate boundaries at areas called
mid-ocean ridges
.
What is the first step of seafloor spreading?
1.
A long crack in the oceanic crust forms at a mid ocean ridge
. 2. Molten material rises and erupts along the ridge.
What is the importance of seafloor spreading?
Seafloor spreading proves that
the ocean itself is a site of tectonic activity
. Seafloor spreading is just one part of plate tectonics. Subduction is another. Subduction happens where tectonic plates crash into each other instead of spreading apart.
Which of the following is evidence of seafloor spreading?
Several types of evidence supported Hess’s theory of sea-floor spreading:
eruptions of molten material, magnetic stripes in the rock of the ocean floor
, and the ages of the rocks themselves.
What is one piece of evidence of seafloor spreading?
There is lots of evidence that proves that seafloor spreading is occurring. One piece of evidence is
mid-ocean ridges
. Rocks found near mid-ocean ridges are young and get older as the distance from the ocean ridge increases.
What causes seafloor spreading quizlet?
During sea-floor spreading,
magma erupts along a mid-ocean ridge to form new oceanic
lithosphere. The floor then moves away from the ridge, often toward a trench at the edge of the ocean basin. … The pattern shows that ocean floor forms along mid-ocean ridges and then moves away from the ridge.
What are the 4 steps of seafloor spreading?
- Magma comes out of the rift valley.
- Magma cools to rock and hardens.
- Rock is pushed away as new rock is formed at MOR.
- Oceanic crust and continental crust meet at the trench.
- Oceanic crust bends down under the continental crust.
- Gravity pulls rock towards mantle.
- Rock melts to mantle.
What are the three types of seafloor spreading?
There are three types of plate-plate interactions based upon relative motion: convergent, where plates collide,
divergent
, where plates separate, and transform motion, where plates simply slide past each other.
What are three pieces of evidence for seafloor 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 is seafloor spreading and why is it important?
Today it refers to the
processes creating new oceanic lithosphere
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
Is the seafloor spreading accepted?
Seafloor spreading proves that
the ocean itself is a site of tectonic activity
. Seafloor spreading is just one part of plate tectonics. Subduction is another. Subduction happens where tectonic plates crash into each other instead of spreading apart.
What happens to the seafloor at 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.
