the relatively thick part of the earth's crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.
the relatively thin part of the earth's crust that underlies the ocean basins. It is geologically young compared with the continental crust and consists of basaltic rock overlain by sediments.
the rigid outer part of the earth, consisting of the crust and upper mantle.
The blanket of gas on the surface of a planet or satellite.
Convection currents in the magma drive plate tectonics. Heat generated from the radioactive decay of elements deep in the interior of the Earth creates magma (molten rock) in the aesthenosphere. The aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the Earth that extends to 2900 km.
Polar ice caps are dome-shaped sheets of ice found near the North and South Poles. They form because high-latitude polar regions receive less heat from the Sun than other areas on Earth. ... The polar ice caps contain the majority of Earth's supply of freshwater.