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Name:  Laura Maria W.
Status: Student
Age: 16
Location: N/A
Country: N/A
Date: October 31, 2003

Why do seismic waves bend when they reach the boundary between the Earths mantle and core? Why do they then carry on bending as they go through the mantle?

The "long" answer is complicated. The short answer is that the speed of the wave depends upon the properties of the medium through which it is traveling -- particularly the density of the medium. Just as light is "bent" when it passes through glass or water because the speed of light is different in different media, so too seismic waves are "bent" when they pass through media of different densities.

Vince Calder

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