Sea Floor Magnetism Theory

Strong evidence of seafloor spreading and plate tectonics.

Sea floor magnetism theory.

What evidence supports hess s theory of seafloor spreading. It states that the earth s oceanic crust acts as a recorder of reversals in the geomagnetic. Evidence of sea floor spreading. Definition theory facts.

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. Harry hess s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. Sometimes for reasons unknown the magnetic poles switch positions. The regions that hold the unique record of earth s magnetic field lie along the mid ocean ridges where the sea floor is spreading.

This evidence was from the investigations of the molten material seafloor drilling radiometric age dating and fossil ages and the magnetic stripes. Was proven as patterns of magnetic field polarity preserved in seafloor basalt and by age dating of the rocks. The models show a ridge a about 5 million years ago b about 2 to 3 million years ago and c in the present. Paleomagnetism or palaeomagnetism in the united kingdom is the study of the record of the.

The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century. Scientists discovered that new molten materials from inside earth create new crust. 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. The pattern of magnetic strips shows that the seafloor is expanding at mid ocean ridges.

With reversed polarity the north and south poles are in the opposite position during wwii magnetometers attached to ships to search. Check all that apply. If the oceanic crust reaches a deep sea trench it sinks into the trench and is lost into the mantle. The magnetic stripes continue across the seafloor.

Magnetic stripes are the result of reversals of the earth s field and seafloor spreading. 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. During normal polarity the north and south poles are aligned as they are now.

North becomes south and south becomes north.