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What was Harry Hess seafloor spreading hypothesis?

What was Harry Hess seafloor spreading hypothesis?

Hess envisaged that oceans grew from their centres, with molten material (basalt) oozing up from the Earth’s mantle along the mid ocean ridges. This created new seafloor which then spread away from the ridge in both directions.

When did Harry Hess prove seafloor spreading?

After much thought, he proposed in 1960 that the movement of the continents was a result of sea-floor spreading. In 1962, he added a geologic mechanism to account for Wegener’s moving continents.

How does the age of the seafloor support seafloor spreading?

The age, density, and thickness of oceanic crust increases with distance from the mid-ocean ridge. Oceanic crust slowly moves away from mid-ocean ridges and sites of seafloor spreading. As it moves, it becomes cooler, more dense, and more thick.

How old is seafloor spreading?

The two parts of the oceanic plate are pulled apart, and magnetic stripes become older as they move away from the mid-ocean ridge. The figure shows the spreading ridge about 5 million years ago (a), about 2 to 3 million years ago (b) and nowadays (c). Courtesy of the U.S Geological Survey.

Which is one piece of evidence of seafloor spreading?

There is lots of evidence that proves that seafloor spreading is occurring. One piece of evidence is mid-ocean ridges. Rocks found near mid-ocean ridges are young and get older as the distance from the ocean ridge increases.

What are the evidence of 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 is the first step of seafloor spreading?

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

WHO confirmed seafloor spreading?

Harry Hess
Alfred Wegener produced evidence in 1912 that the continents are in motion, but because he could not explain what forces could move them, geologists rejected his ideas. Almost 50 years later Harry Hess confirmed Wegener’s ideas by using the evidence of seafloor spreading to explain what moved continents.

What is the evidence of seafloor spreading?

What is one piece of evidence of seafloor spreading?

What causes the seafloor to spread?

Sea-floor spreading is what happens at the mid-oceanic ridge where a divergent boundary is causing two plates to move away from one another resulting in spreading of the sea floor. As the plates move apart, new material wells up and cools onto the edge of the plates.

What are two pieces 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.

How did Harry Hess come up with the seafloor spreading hypothesis?

The seafloor spreading hypothesis was proposed by the American geophysicist Harry H. Hess in 1960. On the basis of Tharp’s efforts and other new discoveries about the deep-ocean floor, Hess postulated that molten material from Earth’s mantle continuously wells up along the crests of the mid-ocean ridges…

Who is the founder of the seafloor spreading theory?

Seafloor spreading was proposed by an American geophysicist, Harry H. Hess in 1960. By the use of the sonar, Hess was able to map the ocean floor and discovered the mid-Atlantic ridge (mid-ocean ridge). He also found out that the temperature near to the mid-Atlantic ridge was warmer than the surface away from it.

Is there any evidence 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.

When did Harry Hammond Hess publish his theory?

Harry Hammond Hess. He published ‘ The History of Ocean Basins ‘ in 1962, in which he outlined a theory that could explain how the continents could actually drift. This theory later became known as ‘ Sea Floor Spreading ‘.