The earth is divided into four main layers: the inner core, outer core, mantle, and crust. Compressional P waves will travel and refract through both fluid and solid materials. Shear S waves, however, cannot travel through fluids like air or water. Seismologists noticed that records from an earthquake made around the world changed radically once the event was more than a certain distance away, about 105 degrees in terms of the angle between the earthquake and the seismograph as measured at the center of the earth. After 105 degrees the direct P- and S- waves disappeared almost completely, but slow surface waves and waves taking other paths would arrive from over the horizon. The area beyond 105 degrees distance forms a shadow zone. At larger distances, some P waves that travel through the liquid core (path K on the figure above) would arrive, but still no S waves. The Earth has to have a molten, fluid core to explain the lack of S waves in the shadow zone, and the bending of P waves to form their shadow zone. *
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The earth is divided into four main layers: the inner core, outer core, mantle, and crust. Compressional P waves will travel and refract through both fluid and solid materials. Shear S waves, however, cannot travel through fluids like air or water. Seismologists noticed that records from an earthquake made around the world changed radically once the event was more than a certain distance away, about 105 degrees in terms of the angle between the earthquake and the seismograph as measured at the center of the earth. After 105 degrees the direct P- and S- waves disappeared almost completely, but slow surface waves and waves taking other paths would arrive from over the horizon. The area beyond 105 degrees distance forms a shadow zone. At larger distances, some P waves that travel through the liquid core (path K on the figure above) would arrive, but still no S waves. The Earth has to have a molten, fluid core to explain the lack of S waves in the shadow zone, and the bending of P waves to form their shadow zone. *
* crack.seismo.unr.edu/ftp/pub/louie/class/100/interior.html
I cant, I havent been there