What three types of evidence provided support for the 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 evidence is there for seafloor spread?
The study of the repeated reversal of the Earth’s magnetic poles over time has provided convincing evidence of seafloor spreading. Objective: To explore how magnetic studies and age information provide evidence for seafloor spreading that explains why oceanic crust is younger than continental crust.
What evidence do we have for seafloor spreading?
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 .
How is seafloor spreading explained and proven?
Seafloor spreading is the mechanism by which new seafloor lithosphere is constantly being created at mid-ocean ridges. This theory, introduced by Harry Hess, was proven as patterns of magnetic field polarity preserved in seafloor basalt and by age dating of the rocks .
What is the root cause of seafloor spreading?
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.
What is seafloor spreading and why is it important?
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 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 .
Which is the first step in seafloor spreading process?
1. A long crack in the oceanic crust forms at a mid ocean ridge . 2. Molten material rises and erupts along the ridge.
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.
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 .
Do spreading centers move?
As the two plates move apart from each other, which often occurs at a rate of several centimetres per year, molten rock wells up from the underlying mantle into the gap between the diverging plates and solidifies into new oceanic crust. Spreading centres are found at the crests of oceanic ridges.
Why is Earth not growing in spite 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 . ... Deep below the Earth’s surface, subduction causes partial melting of both the ocean crust and mantle as they slide past one another.
What causes the seafloor to move?
The seafloor changes because of the earth plates moving causing magma to spew in the water. The magma is then pushed outward causing the seafloor to move and change.
Where is the seafloor spreading the fastest?
Some of our recent research involves hydrothermal and structural investigations along Earth’s fastest seafloor spreading center, the 28°S–32°S East Pacific Rise. The fastest present-day seafloor spreading, ~150 km/Myr, occurs along the Pacific-Nazca boundary between the Easter and Juan Fernandez microplates .
Who proved that the seafloor is spreading?
The seafloor spreading hypothesis was proposed by the American geophysicist Harry H. Hess in 1960.
What is the benefits of seafloor spreading?
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.
