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 the evidence for seafloor spreading?
The theory of seafloor spreading states that new ocean crust is continually being formed, and that this crust is slowly carried away from its point of origin over a period of time.
The study of the repeated reversal of the Earth’s magnetic poles over time
has provided convincing evidence of seafloor spreading.
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
.
What are 4 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 the importance of seafloor spreading?
Significance. Seafloor spreading
helps explain continental drift in the theory of plate tectonics
. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.
What is an example of seafloor spreading?
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. … The Mid-Atlantic Ridge, for instance, is a slow spreading center.
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.
What are the steps in the process 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 happens when the seafloor spreads?
Seafloor spreading takes place at
the boundaries of divergent plates
whereby, as the divergent tectonic plates move away from each other, hot convectional currents from the mantle cause the lithosphere (the ocean crust) to become less-dense, ductile, and brittle, and therefore rise above the surrounding crust to form a …
What landforms does seafloor spreading create?
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.
Is the Earth’s diameter getting bigger because of seafloor spreading?
New crust is continually being pushed away from divergent boundaries (where sea-floor spreading occurs), increasing Earth’s surface. But
the Earth isn’t getting any bigger
.
Is the seafloor spreading accepted?
His basic idea of seafloor spreading along mid-oceanic ridges has well withstood the test of time. … Unlike Wegener, he was able to see his seafloor-spreading hypothesis
largely accepted
and confirmed as knowledge of the ocean floor increased dramatically during his lifetime.
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 causes the formation of new seafloor?
Explanation: 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.At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed.
At which boundaries is seafloor destroyed?
You are correct that the seafloor is destroyed at
subduction zones
, but it is simultaneously being created at mid-ocean ridges. see figure 1 . Figure 1: Seafloor spreading at a mid-ocean ridge(where new crust is being created) and it’s destruction at a subduction zone.
Why do tectonic plates move?
The heat from radioactive processes within the planet’s interior causes the plates
to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or tectonic shift.
