Basalt the once molten rock that makes up most new oceanic crust is a fairly magnetic substance and scientists began using magnetometers to measure the magnetism of the ocean floor in the 1950s.
Magnetic stripes on the sea floor are created where.
What they discovered was that the magnetism of the ocean floor around mid ocean ridges was divided into matching stripes on either side of the.
It does however provide evidence that sea floor spreading occurs and hence is evidence for the theory of plate tectonics.
Basalt forming at the ridge crest picks up the existing magnetic polarity.
These surveys revealed a series of invisible magnetic stripes of normal and reversed polarity in the sea floor like that shown in the figure below.
Plate tectonics and reversals of the earth s magnetic field are responsible for the magnetic stripes found on the ocean floor.
9 10 this results in broadly evident stripes from which the past magnetic field polarity can be inferred from data gathered with a magnetometer towed on the sea surface or from an aircraft.
The patterns reflect the creation and spreading of oceanic crust along the mid oceanic ridges.
In the 1960s the past record of geomagnetic reversals of earth s magnetic field was noticed by observing magnetic stripe anomalies on the ocean floor.
Magnetic reversals found in the sea floor do not cause continental drift.
When magma flows out of a mid ocean ridge small magnetic minerals in the magma align themselves to point in the direction of the earth s current magnetic north.