What Are Magnetic Stripes On The Ocean Floor

Tape one end of each piece of audiotape to a flat surface.

What are magnetic stripes on the ocean floor. The specific magnetism of basalt rock is determined by the earth s magnetic field when the magma is cooling. Cut six short pieces each about 2 5 cm long from a length of audiotape. These two things were the magnetic striping on the ocean floor and the age of seafloor rocks. These patterns were unlike any seen for continental rocks.

Magnetic striping magnetic minerals are found in rocks. Plate tectonics and reversals of the earth s magnetic field are responsible for the magnetic stripes found on the ocean floor. What could cause this. 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.

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. 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. Note that the stripes are symmetrical about the central dusky purple stripe. Among the new findings was the discovery of zebra stripe like magnetic patterns for the rocks of the ocean floor.

Touch a bar magnet s north pole to the first piece of. When the rocks are in melted form these minerals will line up with earth s magnetic field. 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. Obviously the ocean floor had a story to tell but what.

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. In the oceans magnetic stripes are symmetrical about a mid ocean ridge axis. This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid ocean ridges. 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 ridge.

This pattern of stripes could represent what scientists see on the seafloor. By using the magnetometer the magnetic polarity will be shown through a timescale that contains the normal and a reverse polarity. Basalt forming at the ridge crest picks up the existing magnetic polarity. The patterns reflect the creation and spreading of oceanic crust along the mid oceanic ridges.

These patterns of stripes provide the history of seafloor spreading. This similar to how iron filing line up when they are next to a magnet as seen in the pictures below. 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.