Question

Which seismic wave refracts and cannot penetrate the core

Answer 1

Recordings of seismic waves from earthquakes led to the discovery of the earth's core and eventual maps of the layers of the Earth's inside. Just as the prism below refracts light at its faces, seismic waves bend, reflect and change speed at the boundaries between different materials below the Earth's surface.

Answer 2

Answer: P waves and S waves travel through the interior of the earth. P waves are the Primary waves and S waves are the Secondary waves.

P waves can travel in both solid as well as in liquid (outer core) whereas S wave can travel only through solid. When P waves enters the outer core, it gets deviated and again enters the outer core with further deviation.

In case of S waves, once it reaches the core-mantle boundary, it reflects to the side of it, forming a shadow zone commonly known as the S wave shadow zone (103°-103°). Thus it cannot penetrate through the outer core.