Sea Floor Spreading Definition Magnetic

The rate at which new oceanic lithosphere is added to each tectonic plate on either side of a mid ocean ridge is the spreading half rate and is equal to half of the spreading rate.

Sea floor spreading definition magnetic.

A process in which new ocean floor is created as molten material from the earth s mantle rises in margins between plates or ridges and spreads out. Encyclopaedia britannica s editors oversee subject areas in which they have extensive knowledge whether from years of experience gained by working on that content or via study for an advanced degree. The minerals contained in the rocks are oriented opposite to the magnetic field. A mid ocean ridge is an underwater mountain system.

As upwelling of magma continues the plates continue to diverge a process known as seafloor spreading. As a general rule fast ridges see spreading rate of more than 9 cm year. Earth s magnetic field because the outer core of earth is liquid iron that revolves around the solid inner core a magnetic field is produced that protects us from harmful things coming from space. Intermediate ridges have a spreading rate of 4 9 cm year while slow spreading ridges have a rate less than 4 cm year.

At spreading centres this crust is separated into parallel bands of rock by successive waves of emergent magma. Samples collected from the ocean floor show that the age of oceanic crust increases with distance from the spreading centre important evidence in favour of this process. The field behaves as if a permanent magnet were located near the center of the earth inclined about 11 degrees from the geographic axis of rotation fig. In the 20th century the magnetic survey was conducted in the mid ocean ridge in order to investigate evidence of sea floor spreading.

The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century. 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 what they discovered was that the magnetism of the ocean floor around. These age data also allow the rate of seafloor spreading to be. Sea floor spreading a.

The earth s magnetic field the earth s magnetic field is thought to arise from the movement of liquid iron in the outer core as the planet rotates. By using the magnetometer the magnetic polarity will be shown through a timescale that contains the normal and a reverse polarity. Additionally spreading rates determine if the ridge is a fast intermediate or slow.