USGS CMG InfoBank: S-Wave Shadow Zone

Source: Annenberg/CPB Resources - Earth Revealed - 3. Earth's Interior

Keywords: "S-wave shadow zone", S-wave, core, "inner core", "outer core"

Our transcription: The S-waves leave a much larger shadow zone because none of them passes through the core.

Given that S-waves cannot traverse liquids, it seems probable that at least part of the Earth's core is liquid.

In fact, the way the seismic waves pass through the core tells us that it consists of two parts, a liquid outer core and a solid inner core.

Study of Earth's interior suggests that this core is composed mostly of iron combined with smaller amounts of lighter elements.