EARTH SCIENCE
VOLCANOES
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
true
|
|
|
false . There, the lava forms NEW oceanic crust.
|
|
|
Either A or B
|
|
|
None of the above
|
Detailed explanation-1: -Answer and Explanation: The Crust is less dense than the Mantle. The Crust has a density of about 2600 kilograms per cubic meter, while the Mantle’s density is 3400 kilograms per cubic meter.
Detailed explanation-2: -Below the crust is the mantle, a dense, hot layer of semi-solid rock approximately 2, 900 km thick. The mantle, which contains more iron, magnesium, and calcium than the crust, is hotter and denser because temperature and pressure inside the Earth increase with depth.
Detailed explanation-3: -The crust, with an average density of around 2.6 grams per cubic centimeter (g/cm3), is less dense than the mantle (average density of approximately 3.4 g/cm3 near the surface, but more than that at depth), and so it is floating on the “plastic” mantle.
Detailed explanation-4: -Molten rock, i.e., magma, is less dense and more buoyant than the surrounding rock, as a result magma rises through Earth’s crust.