What are the five steps of seafloor spreading?

Terms in this set (7)

• 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 is the first step of seafloor spreading process?

The first step in the seafloor spreading comes in the form of cracking up of the oceanic crust. The convection currents manage to push huge amounts of magma under very high pressure and the crust breaks up.

What are the 4 evidences of 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 process of seafloor spreading for kids?

Seafloor spreading happens at the bottom of an ocean as tectonic plates move apart. It forms new crust as the plates move away from each other. The new crust then slowly moves away from the ridge. It is a place of earthquakes and volcanos.

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 are three pieces of evidence for seafloor spreading?

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 are 3 pieces of evidence to support that seafloor spreading is happening?

Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples. This evidence also led sci- entists to look again at Wegener’s theory of continental drift.

Where does seafloor spreading 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.

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 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 sea-floor spreading?

Magma comes out of the rift valley.

How would you describe the process of seafloor spreading?

Seafloor spreading is a geological process which involves the splitting of tectonic plates and their movement away from each other . Like all geological processes which involves tectonic activity, seafloor spreading is caused by mantle convection.

How fast does seafloor spread?

How Fast is the Seafloor Spreading The latest magnetic imaging result suggests that the Atlantic Ocean is expanding at a rate of between 5 and 10 centimeters a year while in the Pacific some areas are expanding as much as 13 centimeters.

How do scientists prove the seafloor is spreading?

The magnetism of mid-ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century. Basalt, the once-molten rock that makes up most new oceanic crust, is a fairly magnetic substance, and scientists began using magnetometers to measure the magnetism of the ocean floor in the 1950s. What they discovered was that the magnetism of the ocean floor around mid-ocean ridges was divided into matching “stripes” on either side of the ridge.