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Do iron rich rocks have reversed polarity or no magnetic proparty?
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The patterns of iron particles found in sea floor rocks result from what?
The earths magnetic polarity at the time of rock formation.
Which aspect of magnetic reversal provides evidence of continental drift?
Periodically, the magnetic field of the earth reverses polarity. The direction of the magnetic field is recorded in the magnetic properties of rocks when they are erupted. Rocks are being continuously added at sea floor spreading regions, and thus the magnetic reversals are recorded as pairs of parallel 'stripes' alongside the mid ocean spreading ridge.
Why are magnet patterns important evidence for plate tectonics?
magnetic rocks on the ocean floor show that the Earths magnetic field has been frequently reversed forming new sea floor.
What is the evidence of pole reversal?
The evidence for Earth's magnetic pole reversals comes from the Geological record. If you look at the fossil polarity of a section of sea floor taken across and to either side of a mid oceanic ridge, there is a mirror pattern of stripes where the rocks have reversed polar directions. Similarly the poles of the Sun reverse every 11 years as the sun goes through a maxima and minima.
What are reversals?
In the past, the polarity of the Earth's magnetic field has reversed, many times over. This was discovered in samples of the rocks of the ocean floor at mid-ocean ridges, where matching patterns of magnetic polarity were discovered on each side of the mid ocean ridge. It is believed that the magnetic field is caused by electrical currents in the Earth's interior. [We know that the interior is too hot to sustain the magnetism of a bar magnet. As proved by the Curie's.] If these currents circulate parallel to the equator, then they would be pretty stable. but we know that the poles are moving. This may indicate that the path of electrical conduction is not a simple circle. We just have to wait. The earth's magnetic field is caused by the effect of the Earth's rotation on the liquid iron core. This field occasionally flips so that the direction that was magnetic north becomes magnetic south and what was magnetic south becomes magnetic north. This is called a magnetic reversal and these reversals can be detected in Earth's lava rocks which lock in the direction of the current field when they cool and solidify. Earth's magnetic field flips about once every 100 thousand years. The Sun goes through similar magnetic reversal cycles but on the Sun the reversals happen about once every 11 years. Please see the related link for more information.
Why is it believed that the Earth's magnetic field has reversed its polarity in the past?
By observing magnetic rocks in geological deposits.By observing magnetic rocks in geological deposits.By observing magnetic rocks in geological deposits.By observing magnetic rocks in geological deposits.
How is the polarity of Earth's magnetic field recorded in the sea floor?
The polarity of the Earth's magnetic field is recorded in igneous rocks, and reversals.
What is the result of Magnetic reversals?
The north pole becomes the south pole and vice versa. Also any rocks cooling in the reversed field will trap the magnetic polarity prevalent at their time of cooling. This means we can can trace the history of past magnetic reversals.
Describe how the polarity of earth's magnetic field is recorded in the sea-floor?
The polarity of the Earth's magnetic field is recorded in igneous rocks, and reversals.
What happened to the magnetic orientation of rocks as the poles reversed?
There is nothing -_-
Scientists used the pattern of alternating normal and reversed polarity in rocks to create the geomagnetic?
time scale
Is the ocean floor made out of a pattern of magnetized strips?
Yes, the igneous rocks of the ocean floor exhibit a pattern of oppositely polarized magnetic strips. This demonstrates that the earth's magnetic field has reversed polarity (i.e. swapped north and south poles) several times in the past.
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.
The alignment of iron minerals in rocks when they are formed reflects the fact that Earth's has reversed itself several times in the past?
magnetic field.
How are the rocks organized on the mid-Atlantic ridge?
They are arranged in a pattern with magnetic strips having reversed polarities.
The patterns of iron particles found in sea floor rocks result from what?
The earths magnetic polarity at the time of rock formation.
What happens in a magnetic reversal?
The Earth's magnetic polarity reverses. On effect is that remnant magnetism induced in igneous rocks stays, recording the change, and these have been measured to analyse the effect.
