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.
Who discovered magnetic striping?
Vine and Matthews noticed there was a symmetrical pattern of magnetic stripes on either side of the mid ocean ridges. In addition when the basalts of the sea floor were dated, they were found to be the same age at similar distances away from the ridge on each side.
How were magnetic patterns on the seafloor discovered?
Shipboard magnetometers reveal the magnetic polarity of the rock beneath them. … 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.
Why was the discovery of mid ocean ridges important in the further development of the continental drift theory?
Impact of discovery: seafloor spreading
Alfred Wegener proposed the theory of continental drift in 1912. … The discovery of mid-ocean ridges and the process of seafloor spreading allowed for Wegner’s theory to be expanded so that it included the movement of oceanic crust as well as the continents.
How did the discovery of magnetic reversals advance our understanding of plate tectonics?
Geomagnetic reversals helped to prove the theory of plate tectonics by proving the notion of seafloor spreading. Seafloor spreading occurs on the ocean floor at areas called mid-ocean ridges where magma rises from a fault in the floor and forms new crust as the two plates move apart.
What are magnetic stripes on the ocean floor?
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 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.
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.
Where does seafloor spreading occur?
Seafloor spreading occurs along mid-ocean ridges—large mountain ranges rising from the ocean floor. The Mid-Atlantic Ridge, for instance, separates the North American plate from the Eurasian plate, and the South American plate from the African plate.
Why is the ocean floor not flat?
The difference is sea level is caused by two major factors: tides and ocean currents. Tides are mainly caused by the gravitational pull of the Moon and the Sun, acting on the Earth’s surface. Ocean currents are caused by winds and a mixing of waters with different densities.
What are the 4 evidence of continental drift?
They based their idea of continental drift on several lines of evidence: fit of the continents, paleoclimate indicators, truncated geologic features, and fossils.
What is the best evidence of plate tectonics?
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.
Are continents floating?
The continents do not float on a sea of molten rock. … Under the continents is a layer of solid rock known as the upper mantle or asthenosphere. Though solid, this layer is weak and ductile enough to slowly flow under heat convection, causing the tectonic plates to move.
What is the evidence of plate tectonics?
There is variety of evidence that supports the claims that plate tectonics accounts for (1) the distribution of fossils on different continents, (2) the occurrence of earthquakes, and (3) continental and ocean floor features including mountains, volcanoes, faults, and trenches.
How does the tectonic plates behave?
Plates are composed of lithosphere, about 100 km thick, that “float” on the ductile asthenosphere. … The plates behave as rigid bodies with some ability to flex, but deformation occurs mainly along the boundaries between plates. The plate boundaries can be identified because they are zones along which earthquakes occur.
What is the importance of seafloor spreading in understanding the origin of the plate movement?
Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.