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Describe how the polarity of earth's magnetic field is recorded in the sea-floor?
Wiki User
∙ 9y ago
The polarity of the Earth's magnetic field is recorded in igneous rocks, and reversals.
Wiki User
∙ 9y ago
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What is the pattern of magnetic polarity reversals?
In a geomagnetic reversal, the south and north magnetic poles flip locations. A magnetic pole reversal takes place every 450,000 years on average, but this is not regular. We are way overdue since the last reversal was 780,000 years ago. There is a pattern in the magnetic polarity of basaltic rocks on opposite sides of a mid-ocean ridge. Basalt contains tiny magnetic crystals that point to the location of the north magnetic pole at the time the lava cools. The rocks at the ridge have positive polarity, but on either side of the ridge the polarity is negative, indicating that those lavas cooled when the magnetic field was opposite of what it is today. On either side of the basalt with negative polarity are more rocks with positive polarity. This pattern continues on both sides of the mid-ocean ridge across the ocean basin. The pattern of magnetic polarity is one of the main lines of evidence for seafloor spreading, which is the mechanism for plate tectonics.
How do magnetic reversals provide evidence for sea-floor spreading?
The presence of magnetic domains of alternating orientation parallel to the plate boundaries.
Which evidence causes most scientists to believe that seafloor spreading occurs at the mid-atlantic ridge?
Oceanic crust on both sides ofthe ridge shows matching patterns of reversed and normal magnetic polarity
First related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge?
Lawrence W. Morley, Frederick John Vine, and Drummond Hoyle Matthews were the first to tie magnetic stripe anomalies to seafloor spreading. The magnetic anomalies was the first evidence that supported the theory of seafloor spreading.
What structure on the seafloor would have magnetic striping?
astherosphere
What is the pattern of magnetic polarity reversals?
In a geomagnetic reversal, the south and north magnetic poles flip locations. A magnetic pole reversal takes place every 450,000 years on average, but this is not regular. We are way overdue since the last reversal was 780,000 years ago. There is a pattern in the magnetic polarity of basaltic rocks on opposite sides of a mid-ocean ridge. Basalt contains tiny magnetic crystals that point to the location of the north magnetic pole at the time the lava cools. The rocks at the ridge have positive polarity, but on either side of the ridge the polarity is negative, indicating that those lavas cooled when the magnetic field was opposite of what it is today. On either side of the basalt with negative polarity are more rocks with positive polarity. This pattern continues on both sides of the mid-ocean ridge across the ocean basin. The pattern of magnetic polarity is one of the main lines of evidence for seafloor spreading, which is the mechanism for plate tectonics.
What did the magnetic strips prove in seafloor spreading?
They proved that the seafloor was spreading.
What is the most important in providing support for the sea floor spreading hypothesis?
"Magnetic Polarity: the North and South magnetic poles have switched positions throughout Earth's history... the record of magnetic polarity in the rocks of the ocean floor provided unequivical support for the seafloor spreading hypothesis." - as quoted in chp. 4, pg. 94, from the textbook "The Good Earth: Introduction To Earth Science"
How a prediction and then evidence of magnetism in rocks on the ocean floor proved that the seafloor spreads?
The Earth's magnetic reversals have been recorded in newly forming oceanic seafloor basalt by the orientation of magnetic minerals which become frozen in place as the magma hardens. When the next reversal occurs, it as well becomes part of the ocean floor magnetic record.
How do magnetic reversals provide evidence for sea-floor spreading?
The presence of magnetic domains of alternating orientation parallel to the plate boundaries.
First related the symmetrical magnetic patterns in seafloor basalts to seafloor spreading at a mid-ocean ridge?
Lawrence W. Morley, Frederick John Vine, and Drummond Hoyle Matthews were the first to tie magnetic stripe anomalies to seafloor spreading. The magnetic anomalies was the first evidence that supported the theory of seafloor spreading.
Which evidence causes most scientists to believe that seafloor spreading occurs at the mid-atlantic ridge?
Oceanic crust on both sides ofthe ridge shows matching patterns of reversed and normal magnetic polarity
What do the magnetic stripes om the seafloor represent?
When Earth's magnetic poles have reversed themselves.
What do magnetic anomalies provide evidence of?
seafloor spreading
What structure on the seafloor would have magnetic striping?
astherosphere
How does magnetic stripes prove seafloor spreading?
ddd
What was the theory that was shown to be correct by age evidence and magnetic clues?
Magnetic Reversal
