Question: Where Does Seafloor Spreading Occur *?

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 are the causes 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 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 the 4 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 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.

How do the continents move?

Today, we know that the continents rest on massive slabs of rock called tectonic plates. The plates are always moving and interacting in a process called plate tectonics. … As the seafloor grows wider, the continents on opposite sides of the ridge move away from each other.

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. This evidence led scientists to look again at Wegener’s hypothesis of continental drift.

What is the process of subduction?

Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced to sink due to high gravitational potential energy into the mantle. Regions where this process occurs are known as subduction zones.

What is seafloor spreading 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 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.

What is the seafloor spreading theory?

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. …

What 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 was probably the first evidence that led?

Alfred Wegener is credited with developing the continental drift hypothesis. What was probably the first evidence that led some to suspect the continents were once connected? The puzzle-like fit of the continents, especially Africa and South America.

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.

Where do Seafloors with older ages tend to be found?

The next oldest seafloor is found at the margins of the north Atlantic Ocean and the northwestern Pacific Ocean, as far as possible from the mid-ocean ridges where they were created. These parts of the seafloor are about 200 million years old. Age of the oceanic crust. Courtesy of NOAA.

How old is the seafloor?

150 million yearsVery little of the sea floor is older than 150 million years. This is because the oldest sea floor is subducted under other plates and replaces by new surfaces. The tectonic plates are constantly in motion and new surfaces are always being created.

Who discovered seafloor spreading?

Harry HessHarry Hess was a geologist and Navy submarine commander during World War II. Part of his mission had been to study the deepest parts of the ocean floor. In 1946 he had discovered that hundreds of flat-topped mountains, perhaps sunken islands, shape the Pacific floor.

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.

Does the Earth get 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.

What is the first step of seafloor spreading quizlet?

1. A long crack in the oceanic crust forms at a mid ocean ridge. 2. Molten material rises and erupts along the ridge.