The three are different. The first is Molten Material,which is indeed erupting along mid-ocean ridges. The scientists dived to the ocean floor in Alvin, a small sumbarine. Alvin was built to withstand the crushing pressures four kilometers down in the ocean. A ridge's central valley, Alvin's crew found strange rocks shaped like pillows. Other rocks looked like toothpaste squeezed from a tube. Such rocks form only when molten material hardens quickly under again and again along the mid-ocean ridges.
The second is Magnetic Stripes, which are patterns of the ocean floor that provided more support for sea-floor spreading. Earth's magnetic poles have reversed themselves many times during Earth's history. The last reversal happened 780,000 years ago.
The third and final one is Drilling Samples, which came from rock samples obtained by drilling into the ocean floor. The Glomar Challenger, a drilling ship built in 1968, gathered the samples. The Glomar Challenger sent drilling pipes through water six kilometers deep to drill holes in the ocean floor. This feat has been compared to digging a hole into the sidewalk from the top of the Empire State Building.
Information from: California Earth Science Textbook, pages 152-153.
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-SmallvilleGrl
Magnetic stripes on the seafloor showed alternating patterns of normal and reversed polarity, matching Earth's magnetic field reversals. Age dating of seafloor rocks revealed that rocks were youngest along mid-ocean ridges and oldest near continental margins. Sediment thickness on the seafloor was thinnest at mid-ocean ridges and thickest near the continents, supporting the idea of seafloor spreading.
Typical rates of spreading average around 5 centimeter (2 inches) per year.
The ages of the rocks become older the farther the way they are from the ridges. The closer they are the younger it is. This leaves evidence to the seafloor spreading theory.
Oceanic currents themselves do not directly cause seafloor spreading. Seafloor spreading is primarily driven by tectonic forces, specifically the movement of tectonic plates away from each other at mid-ocean ridges. This movement leads to the upwelling of magma from the mantle, creating new oceanic crust at the spreading center. Ocean currents can affect the distribution of heat and nutrients in the ocean, but they do not play a direct role in the process of seafloor spreading.
Magnetism is used to support the theory of seafloor spreading through the study of magnetic stripes on the seafloor. These stripes are aligned with the Earth's magnetic field and provide evidence for the process of seafloor spreading, where new oceanic crust is formed at mid-ocean ridges. As the crust cools and solidifies, the magnetic minerals in the rocks align with the Earth's magnetic field, creating a record of magnetic reversals over time that support the theory of seafloor spreading.
They proved that the seafloor was spreading.
A diagram that shows how seafloor spreading works.
Gravity in the oceanic crust is responsible for seafloor spreading.
Seafloor spreading is triggered by a rift in a continental land mass.
The observation of the alternating magnetic stripes on the seafloor was instrumental in formulating the hypothesis of seafloor spreading.
Seafloor Spreading helped move the Continents to their current location.
Seafloor Spreading
how am i suposed to know
No, seafloor spreading does not hold the plates in place. Seafloor spreading is a process that occurs at mid-ocean ridges where new oceanic crust is formed and spreads apart. It is driven by the movement of tectonic plates, which are actually responsible for holding the seafloor in place.
When seafloor spreading occurs, it pushes the underground magma up though the new crust, creating a sort of volcano out of the new crust. Magma is a very important part in seafloor spreading. :]
Magnetic stripes on the seafloor showed alternating patterns of normal and reversed polarity, matching Earth's magnetic field reversals. Age dating of seafloor rocks revealed that rocks were youngest along mid-ocean ridges and oldest near continental margins. Sediment thickness on the seafloor was thinnest at mid-ocean ridges and thickest near the continents, supporting the idea of seafloor spreading.
Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics.