The striped magnetic pattern develops because, as oceanic crust pulls apart, magma rises to the surface at mid-ocean ridges and spills out to create new bands of ocean floor. … Later, after the planet’s magnetic field flips again, the next stripe of new ocean floor aligns its polarity in the opposite direction.
Where are magnetic stripes on the seafloor created?
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.
How is magnetic striping evidence of plate tectonics?
During times of normal magnetic polarity, the rocks being created stayed normal. … If they were created during times of reverse polarity, the rocks would freeze that magnetic orientation in place.
What are the zebra stripes on the ocean floor proof of?
Magnetic ‘zebra stripes’
In the late 1960s, this phenomenon provided crucial evidence confirming that the seafloor was indeed spreading apart. This concept is at the core of the revolutionary theory of “plate tectonics.”
What causes the strange stripes on the seafloor?
When scientists plotted the points of normal and reversed polarity on a seafloor map they made an astonishing discovery: the normal and reversed magnetic polarity of seafloor basalts creates a pattern. Stripes of normal polarity and reversed polarity alternate across the ocean bottom.
What the magnetic stripes on the ocean floor indicate?
Scientists discovered that the rock that makes up the ocean floor lies in a pattern of magnetized “stripes.” These stripes hold a record of reversals in Earth’s magnetic field. The rock of the ocean floor contains iron. The rock began as molten material that cooled and hardened.
What is the process of magnetic striping?
At spreading centres, this crust is separated into parallel bands of rock by successive waves of emergent magma. When Earth’s geomagnetic field undergoes a reversal, the change in polarity is recorded in the magma, which contributes to the alternating pattern of magnetic striping on the seafloor.
What are the lines of evidence that support the plate movement?
Modern continents hold clues to their distant past. Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. Fossils tell us when and where plants and animals once existed.
Where are magnetic stripes found?
In most magnetic stripe cards, the magnetic stripe is contained in a plastic-like film. The magnetic stripe is located 0.223 inches (5.66 mm) from the edge of the card, and is 0.375 inches (9.52 mm) wide. The magnetic stripe contains three tracks, each 0.110 inches (2.79 mm) wide.
What has caused the zebra pattern in the rock of the ocean floor?
What has caused the “zebra” pattern in the rock of the ocean floor? A magnetic reversal happens. … Rocks makes up the seafloor has iron in it and as the mid ocean ridge cools little pieces of iron “line up” with Earth’s magnetic field and then they stay like the magnetic field is preserved and the seafloor spread.
Where is the youngest material in the sea floor found?
The youngest crust of the ocean floor can be found near the seafloor spreading centers or mid-ocean ridges. As the plates split apart, magma rises from below the Earth’s surface to fill in the empty void.
Why is the oceanic crust younger than the continental crust?
Why is the seafloor so young? It is due to the process of subduction; oceanic crust tends to get colder and denser with age as it spreads off the mid-ocean ridges. … As the continental crust is lighter than the oceanic crust, the continental crust cannot subduct.
Which magnetic stripe is the oldest How do you know?
The magnetic pole reverses from time to time. The north pole becomes the south pole, and the south pole becomes the north pole. Rocks of normal and reversed polarity are found in stripes symmetrically about the mid-ocean ridge axis. The seafloor is youngest at the ridge crest and oldest far away from the ridge crest.
How magnetic symmetry can be used as evidence of seafloor spreading?
Identify how magnetic symmetry can be used as evidence of sea-floor spreading. As the sea floor spreads the magnetic orientation in the rocks as they cooled is preserved. As the earth’s magnetic field changes then a distinct pattern is imprinted in the rocks.
How does seafloor spreading occur?
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. Eventually, the crust cracks.