- Where does seafloor spreading occur?
- Which magnetic stripe is the oldest How do you know?
- How do the magnetic patterns on the seafloor develop?
- What are the three types of seafloor spreading?
- What is the theory of seafloor spreading?
- How magnetic symmetry can be used as evidence of seafloor spreading?
- What causes the strange stripes on the seafloor?
- How do magnetic minerals help support the theory of seafloor spreading?
- What are the causes of seafloor spreading?
- What is the major evidence that seafloor spreading creates new lithosphere?
- What is the main reason that magma forms during seafloor spreading at oceanic ridges?
- What pattern can be found on the seafloor?
- What causes paleomagnetism?
- What does the pattern of magnetic stripes on the seafloor indicate?
Where does seafloor spreading occur?
Sea-floor spreading is what happens at the mid-oceanic ridge where a divergent boundary is causing two plates to move away from one another resulting in spreading of the sea floor.
As the plates move apart, new material wells up and cools onto the edge of the plates..
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 do the magnetic patterns on the seafloor develop?
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.
What are the three types of seafloor spreading?
There are three types of plate-plate interactions based upon relative motion: convergent, where plates collide, divergent, where plates separate, and transform motion, where plates simply slide past each other.
What is the theory of seafloor spreading?
Seafloor spreading is the mechanism by which new seafloor lithosphere is constantly being created at mid-ocean ridges. This theory, introduced by Harry Hess, was proven as patterns of magnetic field polarity preserved in seafloor basalt and by age dating of the rocks.
How magnetic symmetry can be used as evidence of seafloor spreading?
Explanation: Magnetic symmetry was the first evidence that lead to the theory of sea floor spreading. During World War II submarine warfare caused the intense study of magnetism on the ocean floor. The magnetic symmetry made spotting local abnormalities like a steel submarine easier to spot.
What causes the strange stripes on the seafloor?
Seafloor Magnetism 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.
How do magnetic minerals help support the theory of seafloor spreading?
Iron bearing minerals support seafloor spreading because they can record the earth’s magnetic field direction when they form. … hot, less-dense material rises toward the surface at mid ocean ridges, then it flows sideways carrying the seafloor away from the ridge in both directions.
What are the causes of seafloor spreading?
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.
What is the major evidence that seafloor spreading creates new lithosphere?
When the Earth’s magnetic field reverses, the magnetized minerals align in the opposite direction. 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 is the main reason that magma forms during seafloor spreading at oceanic ridges?
When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere. The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones, rather than magma pressure, although there is typically significant magma activity at spreading ridges.
What pattern can be found on the seafloor?
When scientists studied the magnetic properties of the seafloor, they discovered normal and reversed magnetic stripes with different widths. These magnetic patterns are parallel to the mid-ocean ridges and symmetrical on both sides.
What causes paleomagnetism?
Paleomagnetism is possible because some of the minerals that make up rocks—notably magnetite—become permanently magnetized parallel to the earth’s magnetic field at the time of their formation. … When the deposit into which they settle hardens into rock, the magnetization will be fixed.
What does the pattern of magnetic stripes on the seafloor 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.