EARTH SCIENCE
TECTONICS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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crustal plates sinking due to density differences
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new rock forming between two crustal plates at a mid-ocean ridge
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water pressure at great depths pushing two crustal plates apart
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deep ocean currents forcing crustal plates apart
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Detailed explanation-1: -Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow, churning motion of Earth’s mantle. Convection currents carry heat from the lower mantle and core to the lithosphere .
Detailed explanation-2: -Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.
Detailed explanation-3: -When two plates are moving away from each other, we call this a divergent plate boundary. Along these boundaries, magma rises from deep within the Earth and erupts to form new crust on the lithosphere. Most divergent plate boundaries are underwater and form submarine mountain ranges called oceanic spreading ridges.
Detailed explanation-4: -divergent plate boundary-a boundary between two plates that move away from one another; new lithosphere is created between the spreading plates. lithosphere-the rigid, outermost layer of the Earth; includes crust and uppermost mantle and is about 100 km thick.
Detailed explanation-5: -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.