Sea Floor Magnetism Theory

The pattern of magnetic strips shows that the seafloor is expanding at mid ocean ridges.

Sea floor magnetism theory.

This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century. It states that the earth s oceanic crust acts as a recorder of reversals in the geomagnetic. New oceanic crust is magnetized as it forms and then it moves away from the ridge in both directions. As oceanic crust forms and spreads moving away from the ridge crest it pushes the continent away from the ridge axis.

What evidence supports hess s theory of seafloor spreading. Paleomagnetism or palaeomagnetism in the united kingdom is the study of the record of the. Harry hess s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. The models show a ridge a about 5 million years ago b about 2 to 3 million years ago and c in the present.

Was proven as patterns of magnetic field polarity preserved in seafloor basalt and by age dating of the rocks. North becomes south and south becomes north. 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. Check all that apply.

Paleomagnetism led the revival of the continental drift hypothesis and its transformation into theories of sea floor spreading and plate tectonics. Magnetic stripes are the result of reversals of the earth s field and seafloor spreading. Scientists discovered that new molten materials from inside earth create new crust. During normal polarity the north and south poles are aligned as they are now.

Sometimes for reasons unknown the magnetic poles switch positions. Seafloor spreading theory that oceanic crust forms along submarine mountain zones known collectively as the mid ocean ridge system and spreads out laterally away from them. The magnetic stripes continue across the seafloor. Definition theory facts.

Strong evidence of seafloor spreading and plate tectonics. The vine matthews morley hypothesis also known as the morley vine matthews hypothesis was the first key scientific test of the seafloor spreading theory of continental drift and plate tectonics its key impact was that it allowed the rates of plate motions at mid ocean ridges to be computed. This evidence was from the investigations of the molten material seafloor drilling radiometric age dating and fossil ages and the magnetic stripes. The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century.

The regions that hold the unique record of earth s magnetic field lie along the mid ocean ridges where the sea floor is spreading.