Sage-Tips

What piece of evidence is considered to be the smoking gun of plate tectonic theory?

magnetic stripes
British geophysicists Frederick Vine and Drummond Matthews had suggested magnetic stripes might prove the theory, and this was the clear evidence. “We had this magic key, this magic magnetic profile,” Pitman said.

How do magnetic reversals support the theory of plate tectonics?

When the Earth’s magnetic field reverses, a new stripe, with the new polarity, begins. Such magnetic patterns led to recognition of the occurrence of sea-floor spreading, and they remain some of the strongest evidence for the theory of plate tectonics.

What evidence makes the theory of plate tectonics?

Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. Fossils tell us when and where plants and animals once existed. Some life “rode” on diverging plates, became isolated, and evolved into new species.

What natural phenomena are explained by the theory of plate tectonics?

The theory of plate tectonics explains most of the features of Earth’s surface. It explains why earthquakes, volcanoes and mountain ranges are where they are. It explains where to find some mineral resources. Plate tectonics is the key that unlocks many of the mysteries of our amazing planet.

How did Harry Hess discover what he discovered on the floor of the Pacific ocean?

Hess discovered that the oceans were shallower in the middle and identified the presence of Mid Ocean Ridges, raised above the surrounding generally flat sea floor (abyssal plain) by as much as 1.5 km. This created new seafloor which then spread away from the ridge in both directions.

What was discovered in 1953 using sonar?

In 1953, scientists discovered that a prominent valley, called the Great Global Rift, ran down the center of these ridges. Intrigued, Hess reexamined the data from a completely fresh, unorthodox perspective.

How do magnetic reversals happen?

These magnetic reversals, in which the direction of the field is flipped, are believed to occur when small, complex fluctuations of magnetic fields in the Earth’s outer liquid core interfere with the Earth’s main dipolar magnetic field to the point where they overwhelm it, causing it to reverse.

How do magnetic reversals provide evidence of the seafloor spreading hypothesis?

A polarity reversal means that the magnetic North flips to where we know the South Pole is. This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges. These patterns of stripes provide the history of seafloor spreading.

Why are magnetic patterns important evidence for plate tectonics?

Magnetic patterns are important evidence for plate tectonics because we can use the magnetic signatures of rock to identify the movement of large…

How does the mid ocean ridge provide evidence for plate tectonics?

From this, scientist found that in the ocean, there were subduction zones where the old ocean crust was subducted into deep ocean trenches. New ocean crust was then created at the mid ocean ridge. All this evidence complied together convinced scientists of the existence of plate tectonics and continental drift.

How does the plate tectonic theory unify the concepts of geology?

The theory of plate tectonics is a unifying theory that helps explain many seeming unrelated geologic phenomena. The theory states that Earth’s lithosphere is broken into numerous slabs or plates which are in constant motion driven by heat flow from within the Earth’s interior (mantle and core).

How can Earth’s magnetic reversals be used to support seafloor spreading theory?

Magnetic reversals occur every so often. When they happen, the Earth’s magnetic field reverses its polarity. In other words, north becomes south and south becomes north. Magnetic reversal proves seafloor spreading because we can see the polarity of the Earth’s magnetic field in rocks.

How did scientists determine the time scale for the magnetic reversals?

By combining magnetic polarity data from rocks on land and on the seafloor with radiometric age dating and fossil ages, scientists came up with a time scale for the magnetic reversals. The first four magnetic periods are: Brunhes normal – present to 730,000 years ago. Matuyama reverse – 730,000 years ago to 2.48 million years ago.

Where can we see the reversal of the solar magnetic field?

This reversal process can be seen in the paleomagnetic record, locked into rocks of the ocean floor and in some lava flows. The reversal process is not literally ‘periodic’ as it is on the sun, whose magnetic field reverses every 11 years.

How long does it take for the earth’s magnetic field to reverse?

The time between magnetic reversals on the Earth is sometimes as short as 10,000 years and sometimes as long as 25 million years; the time it takes to reverse is only about 5,000 years.

What was Wegener’s attitude towards Galileo’s theory?

He just sat smoking his pipe and listening. His attitude seems to have mirrored that of Galileo who, forced to recant Copernicus’ theory that the Earth moves around the sun, is said to have murmured, “Nevertheless, it moves!” Scientifically, of course, Wegener’s case was not as good as Galileo’s, which was based on mathematics.