Users' questions

How did paleomagnetism lead to seafloor spreading theory?

How did paleomagnetism lead to seafloor spreading theory?

Seafloor spreading carried new oceanic crust away from the mid-ocean ridge. This explanation of magnetic striping by paleomagnetism convinced scientists that new oceanic crust was being continually formed at mid-oceanic ridges. Seafloor spreading was accepted as a reality.

Why are there paleomagnetic stripes on the ocean floor?

Magnetic stripes are the result of reversals of the Earth’s field and seafloor spreading. New oceanic crust is magnetized as it forms and then it moves away from the ridge in both directions.

How does paleomagnetism support seafloor spreading and continental drift?

How does paleomagnetism serve as evidence for seafloor spreading? Seafloor spreading partially causes continental drift: heat from inside the earth rises and causes molten rock to be emitted from mid-ocean ridges, causing new rock to form and pushing old rock away from the ride, thus spreading the sea floor.

What do stripes represent for seafloor spreading?

These surveys revealed a series of invisible magnetic “stripes” of normal and reversed polarity in the sea floor, like that shown in the figure below. The patterns reflect the creation and spreading of oceanic crust along the mid-oceanic ridges. Basalt forming at the ridge crest picks up the existing magnetic polarity.

What are the 4 evidences of 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.

What is the concept of seafloor spreading?

Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other. Seafloor spreading and other tectonic activity processes are the result of mantle convection. The less-dense material rises, often forming a mountain or elevated area of the seafloor.

What does seafloor spreading look like?

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 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.

Which is the first step in the 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 3 pieces of evidence that support seafloor spreading?

Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples.

Where do seafloor spreading occur?

mid-ocean ridges
Seafloor spreading occurs along mid-ocean ridges—large mountain ranges rising from the ocean floor. The Mid-Atlantic Ridge, for instance, separates the North American plate from the Eurasian plate, and the South American plate from the African plate.

How are paleomagnetic rocks related to sea floor spreading?

Hence, paleomagnetic rocks (paleo: denoting rocks) on either side of the mid-ocean or submarine ridges provide the most important evidence to the concept of Sea Floor Spreading. Magnetic field records also provide information on the past location of tectonic plates.

How are magnetic stripes recorded on the ocean floor?

Consider the data itself. Ships or submersible vessels make a number of passes over a region of ocean floor, recording magnetic anomalies. The profiles are displayed down the page in a ‘stack’. Then lines are drawn from profile to profile where the researcher guesses common points exist.

How is paleomagnetism related to the continental drift theory?

Paleomagnetic studies of rocks have demonstrated that the orientation of the earth’s magnetic field has frequently alternated (geomagnetic reversal) over geologic time. Paleomagnetism led the revival of the continental drift hypothesis and its transformation into theories of Sea Floor Spreading and Plate Tectonics.

How does seafloor spreading help explain continental drift?

Seafloor spreading helps explain continental drift in the theory of plate tectonics. Rocks on either side of the crest of oceanic ridges having equidistant locations from the crest were found to have similarities both in terms of their constituents, their age and magnetic orientation.