Magnetic stripes in the 20th century the magnetic survey was conducted in the mid ocean ridge in order to investigate evidence of sea floor spreading.
What are magnetic stripes on the ocean floor.
Over time the earth s magnetic field reverses its north to south polarity and the magnetic minerals point in the opposite direction creating a striped pattern.
Among the new findings was the discovery of zebra stripe like magnetic patterns for the rocks of the ocean floor.
Cut six short pieces each about 2 5 cm long from a length of audiotape.
Obviously the ocean floor had a story to tell but what.
The specific magnetism of basalt rock is determined by the earth s magnetic field when the magma is cooling.
This similar to how iron filing line up when they are next to a magnet as seen in the pictures below.
Evidence from magnetic stripes.
Basalt forming at the ridge crest picks up the existing magnetic polarity.
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.
These patterns were unlike any seen for continental rocks.
The patterns reflect the creation and spreading of oceanic crust along the mid oceanic ridges.
In the oceans magnetic stripes are symmetrical about a mid ocean ridge axis.
The pieces should be spaced 1 cm apart and lined up lengthwise in a single row.
Oceanographic exploration in the 1950s led to a much better understanding of the ocean floor.
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.
These two things were the magnetic striping on the ocean floor and the age of seafloor rocks.
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.
By using the magnetometer the magnetic polarity will be shown through a timescale that contains the normal and a reverse polarity.
This pattern of stripes could represent what scientists see on the seafloor.
What could cause this.
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.
When the rocks are in melted form these minerals will line up with earth s magnetic field.
Touch a bar magnet s north pole to the first piece of.
Tape one end of each piece of audiotape to a flat surface.
This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid ocean ridges.
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.
Magnetic striping magnetic minerals are found in rocks.
These patterns of stripes provide the history of seafloor spreading.