Obviously, the ocean floor had a story to tell, but what? In 1962, scientists of the U.S. Naval Oceanographic Office prepared a report summarizing available information on the magnetic stripes mapped for the volcanic rocks making up the ocean floor.
How were the magnetic patterns on the seafloor discovered?
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.
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.
What 2 questions did the discovery of magnetic striping raise?
The discovery of magnetic striping naturally prompted more questions: How does the magnetic striping pattern form? And why are the stripes symmetrical around the crests of the mid-ocean ridges? These questions could not be answered without also knowing the significance of these ridges.5 мая 1999 г.
How do scientists figure out the age of the seafloor?
Scientists can determine the age of the seafloor by examining the changing magnetic field of our planet. … When the lava solidifies at the ridges to form the new seafloor, radioactive elements coming from the mantle are trapped in it.
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.
What kind of rock is the seafloor made of?
What are magnetic stripes on the seafloor?
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.
Where is the youngest material in the seafloor 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.
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.
How old is the oldest seafloor?
approximately 280 million years old
How do magnets affect the human body?
Probably the best-known sensory effect of magnetism is shown in total darkness, when the head of a person whose eyes are fully adapted to the dark is put between the poles of an alternating current magnet. As the field strength is increased, the person will begin to see a faint glow around the visual periphery.
What are the 3 theories of plate tectonics?
Plates interact at three types of plate boundaries: divergent, convergent and transform. Most of the Earth’s geologic activity takes place at plate boundaries. At a divergent boundary, volcanic activity produces a mid ocean ridge and small earthquakes.
Which plates are older?
Types of Plates
Continental: Crust that’s older and thicker, made of lighter-weight rock. Oceanic: Younger and thinner, oceanic crust is made of relatively heavier rock.
What does seafloor spreading look like?
Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other. Seafloor spreading and other tectonic activity processes are the result of mantle convection. … The less-dense material rises, often forming a mountain or elevated area of the seafloor.
Which boundary is the seafloor destroyed?