EVERYDAY SCIENCE

Detailed explanation-1: -The Mantle It is the largest layer of the Earth, 1800 miles thick. The mantle is composed of very hot, dense rock. This layer of rock even flows like asphalt under a heavy weight. This flow is due to great temperature differences from the bottom to the top of the mantle.

Detailed explanation-2: -Continental crust is also less dense than oceanic crust, though it is considerably thicker; mostly 35 to 40 km versus the average oceanic thickness of around 7-10 km. About 40% of the Earth’s surface is now underlain by continental crust.

Detailed explanation-3: -The crust is made of rock and varies between 3 to more than 43 miles (4.8 to 69 kilometers) thick. Even though this layer seems thick, it’s nothing compared to the other three layers. If the Earth was an apple, the crust would only be as thick as the skin!

Detailed explanation-4: -Continental crust is less dense than oceanic crust (2.7 g/cm3 vs. 3 g/cm3), and it is much older. The oldest rocks in continental crust are about 4.4 billion years old, while the oldest oceanic crust only goes back about 180 million years.