Earth's Crust Quiz

The Earth's crust is composed of large amounts of silicon and aluminum and is the outermost layer of the Earth. It is divided into two types: oceanic and continental. The crust is part of the lithosphere and is made up of plates on which the continents and oceans rest.

The lithosphere is the zone of rigid, brittle rock made up of the crust and the upper layer of the mantle. It is related to the Earth's crust and upper mantle as they together form the lithosphere, which is divided into separate plates that move slowly in response to the convecting part of the mantle.

The mantle is the thickest layer of the Earth, approximately 2900km (1800 miles) thick. It is composed of elements such as magnesium, silicon, oxygen, and iron. The mantle is solid but capable of flow, and its convection currents cause changes on the Earth's surface.

The asthenosphere is the semi-rigid part of the middle mantle that flows like hot asphalt under a heavy weight. It is a soft layer of the mantle on which pieces of the lithosphere move. The asthenosphere, also known as the 'weak sphere,' allows the lithospheric plates to move due to its semi-solid/semi-liquid nature.

Convection currents in the middle mantle cause the mantle to 'flow' and contribute to the movement of the lithospheric plates. These currents are responsible for the rise, cooling, and sinking of hot magma, creating a cycle that acts as a conveyor belt for the tectonic plates and causes changes on the Earth's surface.