EARTH SCIENCE
TECTONICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Earth’s magnetic field is so strong it pushes apart iron-filled rocks.
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Earth is growing in size, and the mid-ocean ridges are where the crust has cracked to allow Earth to get bigger.
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Hot magma rises through the boundary at mid-ocean ridges, creating new rock and pushing apart the plates.
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Waves in the ocean pull the plates away from each other.
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Detailed explanation-1: -Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.
Detailed explanation-2: -Magma is pushed up through cracks in the crust along the mid-ocean ridge. As the magma is thrust up and hardens it forms new crust and the ocean floor on both sides of the mid-ocean ridge move outward.
Detailed explanation-3: -Mid ocean Ridges are the most prominent producers of magma globally. The magma is produced by decompression melting, which occurs when two plates move away from each other. This tectonic boundary is a Divergent Boundary. Typically it produces oceanic crust and typically occurs in oceanic crust settings.
Detailed explanation-4: -In 1962, Hess published a new idea that he called seafloor spreading. Hess wrote that hot magma rises up into the rift valley at the mid-ocean ridges. The lava cools to form new seafloor. Later more lava erupts at the ridge.