Question: What Evidence Is Used To Support Seafloor Spreading?

How does it prove seafloor spreading?

Magnetic reversal proves seafloor spreading because we can see the polarity of the Earth’s magnetic field in rocks.

As magma cools, particles in it get “frozen” in the direction of the magnetic field..

What scientist helped discover the process of seafloor spreading?

Harry H. HessThe seafloor spreading hypothesis was proposed by the American geophysicist Harry H. Hess in 1960.

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 tectonic plates to 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.

How did seafloor spreading provide evidence for continental drift?

Seafloor spreading disproves an early part of the theory of continental drift. Supporters of continental drift originally theorized that the continents moved (drifted) through unmoving oceans. Seafloor spreading proves that the ocean itself is a site of tectonic activity.

What is the average speed of seafloor spreading?

approximately 5 centimeters a yearThe average speed of seafloor spreading is approximately 5 centimeters a year. This growth rate can be compared to the growth rate of human fingernails (Krupicka). The global ridge system consists of oceanic ridges. Seafloor spreading occurs at these elevated oceanic ridges and has high heat flow and volcanism.

What is the source of magma for seafloor spreading?

Sea-floor spreading — In the early 1960s, Princeton geologist Harry Hess proposed the hypothesis of sea-floor spreading, in which basaltic magma from the mantle rises to create new ocean floor at mid-ocean ridges.

Which boundary is the seafloor destroyed?

subduction zonesYou 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.

What are 3 types of evidence for 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. This evidence led scientists to look again at Wegener’s hypothesis of continental drift.

What is the first step of seafloor spreading?

Also Know, what is the first step of seafloor spreading quizlet? Sea-Floor Spreading begins at a mid-ocean ridge, which forms along a crack in the oceanic crust. along the ridge, molten material that forms several kilometers beneath the surface rises and erupts.

Why is seafloor spreading important to continental drift?

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. … At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed.

What is the difference between seafloor spreading and continental drift?

Continental drift is a very similar process to seafloor spreading. Continental drift is the gradual movement of continental plates over the Earth’s surface over time. … Seafloor spreading is the formation of new areas of oceanic crust due to the upwelling of magma as oceanic aparts pull apart.

Which is the first step in the seafloor spreading process?

A crack forms in oceanic crust. Molten rock rises up through oceanic crust. Molten rock solidifies at the center of the ridge.

What process recycles the crust?

Crustal recycling is a tectonic process by which surface material from the lithosphere is recycled into the mantle by subduction erosion or delamination.