Magnetic Field Ocean Floor

In sediments the orientation of magnetic particles acquires a slight bias towards the magnetic field as they are deposited on an ocean floor or lake bottom.

Magnetic field ocean floor.

Seafloor spreading and magnetic striping rising magma assumes the polarity of earth s geomagnetic field before it solidifies into oceanic crust. In the ocean floor the magnetization was orderly arranged in long strips. The figure below includes two images of the ocean floor. This is called detrital remanent magnetization.

They record the strength of the magnetic field in rocks on the ocean floor. The strips on the atlantic ocean floor in particular all seemed parallel to the mid atlantic ridge that is a volcanic ridge running roughly north to south with some zigs and zags halfway between europe africa and america. The survey data was used to create three dimensional relief maps of the ocean floor. The ocean floor is uniformly old preserving the earth s 4 6 billion history.

These two things were the magnetic striping on the ocean floor and the age of seafloor rocks. 2 a magnetometer is a device scientists can now use to study the ocean floor. Thermoremanent magnetization is the main source of the magnetic anomalies around mid ocean ridges. 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.

This similar to how iron filing line up when they are next to a magnet as seen in the pictures below. The magnetic field that is produced by the oceans the molten core and rocks in the crust and upper mantle protects the planet from streams of charged particles known as the solar wind. These instruments have been used to map the ocean floor. At spreading centres this crust is separated into parallel bands of rock by successive waves of emergent magma.

This tool can detect small changes in magnetic fields. Plate tectonics and reversals of the earth s magnetic field are responsible for the magnetic stripes found on the ocean floor. The ground of the ocean is made of magnetite that is part of iron rich volcanic rock. 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.

When the earth s magnetic field reverses a new stripe with the new polarity begins. When the rocks are in melted form these minerals will line up with earth s magnetic field. Magnetic striping magnetic minerals are found in rocks. Magnetometers are devices that can detect tiny deviations in the earth s magnetic field.

This rock has strong magnetic properties that allow us to see the history of earth s magnetic field.