How Do Magnetic Stripes Form On The Ocean Floor?
When lava gets erupted at the mid-ocean ridge axis it cools and turns into hard rock. As it cools it becomes permanently magnetized in the direction of the Earth’s magnetic field. … This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges.
How does magnetic striping occur?
Magnetic Striping is when the sea floor is spreading and magma from the mantle is rising through the Earth’s crust. That magma then turns into new crust forming the “Oceanic Crust”.
What causes the strange stripes on the seafloor?
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.
How do magnetic stripes of iron in ocean rock?
How do magnetic stripes of iron in ocean rock provide evidence of seafloor spreading? They show when Earth’s poles reversed. … They reveal differences in the mineral composition of newly created rock. They reveal a matching pattern on either side of the ridge.
How magnetic stripes on the ocean floor are evidence for sea floor spreading?
How do strips of magnetized rock on the ocean floor provide evidence of sea-floor spreading? Strips of ocean-floor basalt record the polarity of Earth’s magnetic field at the time the rock formed. … The pattern shows that ocean floor forms along mid-ocean ridges and then moves away from the ridge.
Why were magnetic patterns found on the ocean floor puzzling?
Why were magnetic patterns found on the ocean floor puzzling? … No rocks were magnetic. They did not show alternating bands of normal and reversed polarity.
Where do magnetic anomaly patterns appear on the ocean floor?
What do the magnetic stripes pattern represents?
This represents periodic reversals in the direction of the Earth’s magnetic field.
How do magnetic stripes show the history of Earth’s magnetic field?
As rocks crystallize from lava at the ridges they literally record the magnetic field of the Earth at the time of their creation. … The two parts of the oceanic plate are pulled apart and magnetic stripes become older as they move away from the mid-ocean ridge.
Why are magnetic stripes in the Pacific Ocean wider than in the Atlantic Ocean?
Magnetic stripes in the Pacific Ocean are wider because the seafloor spreads more rapidly there than in the Atlantic Ocean. … Seafloor sediment increases in thickness away from the mid-ocean ridge because the oceanic crust is older farther away from the ridge.
Which statement accurately describes how magnetic stripes in ocean rock?
Which statement accurately describes how magnetic stripes in ocean rock provide evidence of seafloor spreading? C. The pattern of magnetic strips shows that the seafloor is expanding at mid-ocean ridges.
What is the orientation of the magnetic stripes of iron contained in rocks that support the idea of seafloor spreading?
Answer: When magma rises in the divergent boundary as new crust is formed the iron minerals in the magma align themselves with the earth’s magnetic field before the magma cools to rock. Iron minerals have a ferromagnetic property about them. This is why the rocks layers in the sea floor spreading have bands.
How does Earth’s magnetic field provide evidence for seafloor spreading quizlet?
Sample answer: Molten rock at mid-ocean ridges has magnetized minerals that align with Earth’s magnetic field. … The record of magnetic reversals is carried away from each side of the spreading center of a mid-ocean ridge showing that the molten rock is creating new lithosphere.
What creates magnetic stripes on the seafloor quizlet?
Evidence from magnetic stripes is found on the seafloor. The magnetic stripes are created by the reversal of Earth’s magnetic field. … Subduction happens near trenches so the sea-floor can be melted and solidified again.
What is the evidence for sea floor spreading?
Abundant evidence supports the major contentions of the seafloor-spreading theory. First samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached and the sediment cover is thinner near the ridge.
What causes magnetic stripes on the seafloor quizlet?
Why does the rock of the ocean floor have a pattern of magnetic stripes? The rock of the ocean floor contains iron. As molten material cooled and hardenend the iron bits inside lined up in the direction of Earth’s magnetic poles creating a pattern of magnetized stripes.
How does an ocean basin form?
How are ocean ridges formed a level?
A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range formed by plate tectonics. This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.
How does seafloor spreading relate to the size of the oceans?
Why do magnetic stripes on the ocean floor form a symmetrical pattern on either side of mid-ocean ridges?
At the mid-ocean ridge spreading axis these flips in the direction of the Earth’s magnetic field are recorded in the magnetization of the lava. This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges.
What causes magnetic anomalies on the sea floor?
The marine magnetic anomalies result from the remnant (or permanent) magnetization acquired when the material cooled below its Curie temperature.
How do magnetic anomaly patterns on the ocean floor best serve as evidence for seafloor spreading?
magnetic polarity reversals. How do magnetic anomaly patterns on the ocean floor best serve as evidence for seafloor spreading? The symmetry on either side of mid-ocean ridges shows that new crust is created and then split apart.
What is the ocean floor like where magnetic reversals are seen?
What do you notice about the magnetic stripe pattern on each side of the oceanic ridge?
The stripes are symmetric across the Oceanic Ridge. They create a mirror image. It suggests that new seafloor is formed in the middle (at the Ridge) and some of the new seafloor moves to each side of the Ridge forming a symmetric pattern.
How do Earth’s magnetic signatures support the idea that continents move?
When they added magnetic evidence from a second continent they showed that in the past there had either been two magnetic north poles or the continents had moved. Since there is only one magnetic north pole today they concluded that the simplest explanation is that the continents have moved.
How does magnetic reversal prove seafloor spreading?
Magnetic reversal proves seafloor spreading because we can see the polarity of the Earth’s magnetic field in rocks. As magma cools particles in it get “frozen” in the direction of the magnetic field.
How does a scientist use the magnetic field magnetic strips or magnetic lines in explaining the seafloor spreading theory?
Magnetic polarity stripes give clues to seafloor ages and the importance of mid-ocean ridges in the creation of oceanic crust. Seafloor spreading processes create new oceanic crust at mid-ocean ridges and destroy older crust at deep sea trenches.
How often do Earth’s magnetic poles reverse apex?
These reversals are random with no apparent periodicity to their occurrence. They can happen as often as every 10 thousand years or so and as infrequently as every 50 million years or more.
What is the bottom of the sea called?
Why do you think some magnetic stripes are wider than others?
As you move further away from the ridge crests the age of the magnetic stripes increases. This is due to the process of seafloor spreading that creates new crust and pushes the old crust away. … So the further away from the ridge you go the older the crust will be. Some magnetic stripes are wider than others.
How do the normal and reversed polarity of stripes of ocean floor prove that the Earth’s magnetic field has changed multiple times since its formation?
How do the normal and reversed polarity of stripes of ocean floor prove that the earth’s magnetic field has changed multiple times since its formation? It shows that the oceanic crust created by the upwelling of magma reflects the current magnetic field at that time thus different polarities testify to a change.
How do magnetic stripes of iron in ocean rock provide evidence of seafloor spreading they show when Earth’s poles reversed?
How do magnetic stripes of iron in ocean rock provide evidence of seafloor spreading? … They show how the density of the seafloor has changed. They reveal a matching pattern on either side of the ridge. They reveal differences in the mineral composition of newly created rock.
What did Harry Hess discover about the ocean floor?
Harry 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 do scientists date sea-floor rocks?
Scientists date sea-floor rocks by looking at patterns in the rocks including magnetic patterns and by looking at the geomagnetic reversal time scale. New material is constantly being pushed up from deep below the surface to form the ridge. … As the ridge rises rocks are pushed out to either side.
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