Summary
Highlights
Earth's Internal Structure00:00:03
The Earth is composed of distinct layers categorized by density and physical properties, including the solid inner core, liquid outer core, the massive mantle, and the thin outer crust.
Crustal Differences00:01:43
The Earth has two types of crust: thin, dense oceanic crust made of basalt, and thicker, less dense continental crust made largely of granite, which allows it to float higher.
The Lithosphere and Asthenosphere00:02:27
The asthenosphere is a plastic, flowing layer of the mantle, while the rigid lithosphere—consisting of the crust and upper mantle—floats on top, broken into tectonic plates.
Isostasy and the Moho00:04:13
The Moho marks the boundary between crust and mantle. Isostasy describes the equilibrium process where the lithosphere sinks or rises in the asthenosphere based on added or removed surface weight, similar to an iceberg in water.