SCIENCE
EARTH SCIENCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Earth’s crust becomes cooler.
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Earth’s mantle becomes warmer.
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Earth’s mantle becomes cooler.
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Earth’s outer core becomes warmer.
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Detailed explanation-1: -The decrease in the Earth’s tectonic activity would therefore occur if the Earth’s mantle became cooler, as the tectonic plates move over the magma, which is a paste formed by silicate of iron and magnesium and whose temperature reaches 600° and 1, 200° Celsius, driven by forces from inside the planet.
Detailed explanation-2: -Estimates of the speed with which Earth’s mantle moves range from 1 to 20 cm/year with an average of about 5 cm/year in the case of plate motions to as much as 50 cm/year in hotspots such as the Hawaiian Islands (see Plates, Plumes, And Paradigms (2005) edited by Gillian R.
Detailed explanation-3: -Convection currents drive the movement of Earth’s rigid tectonic plates in the planet’s fluid molten mantle. In places where convection currents rise up towards the crust’s surface, tectonic plates move away from each other in a process known as seafloor spreading (Fig.
Detailed explanation-4: -Which of the following changes would end Earth’s tectonic activity? Earth’s mantle becomes cooler and solid.
Detailed explanation-5: -Mantle convection is the very slow creeping motion of Earth’s solid silicate mantle as convection currents carry heat from the interior to the planet’s surface.