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The Earth has two poles, the north pole and the south pole that behave like giant magnets. The rock on the ocean floor contains iron. The rock began as molten material that cooled and hardened. As the rock cooled, the iron bits inside lined up in the direction of Earth's magnetic poles. This locked the iron bits in place, giving the rocks a permanent "magnetic memory". The stripes are significant because of the "magnetic memory" giving us an idea of what occurred when sea-floor spreading took place.
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Describe how the polarity of earth's magnetic field is recorded in the sea-floor?
Magnetic minerals in the Earth's crust align with the planet's magnetic field at the time of their formation. When new oceanic crust is created at mid-ocean ridges, these minerals record the direction of the Earth's magnetic field on the sea-floor. This creates alternating stripes of normal and reversed polarity as the sea-floor spreads.
How do magnetic stripes show the history of earths magnitic field?
Magnetic stripes on the ocean floor are formed as magma from the mantle rises at mid-ocean ridges and solidifies into rock. The Earth's magnetic field periodically reverses its polarity, causing magnetic minerals in the cooling rock to align with the prevailing magnetic field. These alternating magnetic orientations create stripes of normal and reversed polarity that are preserved in the oceanic crust as it spreads away from the ridges. By studying these magnetic stripes, scientists can reconstruct the history of the Earth's magnetic field reversals and the seafloor spreading process.
Why do magnetic strips appear on the sea floor?
Magnetic stripes on the sea floor form as a result of the movement of tectonic plates. When magma rises to the surface at mid-ocean ridges and solidifies into new rock, it records the Earth's magnetic field at the time. This creates alternating stripes of normal and reversed polarity as the Earth's magnetic field has flipped multiple times throughout history.
How were scientists able to use rock on the ocean floor to determine that the Earth and magnetic field has changed direction?
Scientists studied the alignment of magnetic minerals in oceanic rocks to determine that the Earth's magnetic field has undergone reversals in polarity. By analyzing the magnetic "stripes" on the ocean floor, they found alternating bands of rocks with normal and reversed polarity, suggesting that Earth's magnetic field has changed direction over time.
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.
On the real ocean floor alternating stripes of normal and reversed polarity are not all of equal width. What does this tell you about the lengths of time represented by normal and reversed polarity?
It would indicate that the length of time between reversals is not predictable.
When new rock is added to an oceanic ridge the magnetized strips on side of the ridge are evidence of sea floor spreading this is because the rock the two sides of the ridge?
are equal in width and polarity
How magnetic reversals provide evidence for sea floor spreading?
Because of the stripes at the sea floor which are magnetic minerals
What Causes of magnetic striping?
Magnetic striping on the ocean floor is caused by the movement of tectonic plates. As new oceanic crust is formed at mid-ocean ridges, Earth's magnetic field causes iron-rich minerals in the crust to align and record the direction of the magnetic field at that time. This results in alternating patterns of magnetic polarity stripes on the ocean floor.
What geologic discovery in the 1960's provided the scientific evidence to verify the occurrence of continental drift?
The discovery was the presence of magnetic stripes on the ocean floor which indicated that the seafloor was spreading, solidifying from melt, and the magnetic minerals contained therein were aligning themselves with the magnetic alignment of the Earth at the time of their solidification.
How does magnetic stripes prove seafloor spreading?
Magnetic stripes on the seafloor provide evidence for seafloor spreading because they show alternating bands of normal and reversed polarity along mid-ocean ridges. These stripes form as new oceanic crust is created at mid-ocean ridges, with the Earth's magnetic field aligning minerals in the crust in the direction of the prevailing polarity at the time of its formation. By collecting and analyzing samples from the ocean floor, scientists can observe these magnetic patterns and confirm the process of seafloor spreading over geologic time scales.
Strips of alternating magnetic polarities found in rocks in the ocean basins?
They are known as magnetic stripes and are formed as new sea floor is created at mid-ocean ridges. When molten rock solidifies, it preserves the direction of Earth's magnetic field at that time, creating a record of magnetic reversals in the oceanic crust. The alternating stripes of normal and reversed polarity provide evidence for seafloor spreading and plate tectonics.
