<P> Its name , S for secondary , comes from the fact that it is the second direct arrival on an earthquake seismogram , after the compressional primary wave , or P - wave , because S - waves travel slower in rock . Unlike the P - wave , the S - wave can not travel through the molten outer core of the Earth , and this causes a shadow zone for S - waves opposite to where they originate . They can still appear in the solid inner core : when a P - wave strikes the boundary of molten and solid cores , S - waves will then propagate in the solid medium . And when the S - waves hit the boundary again they will in turn create P - waves . This property allows seismologists to determine the nature of the inner core . </P>
<P> Its name , S for secondary , comes from the fact that it is the second direct arrival on an earthquake seismogram , after the compressional primary wave , or P - wave , because S - waves travel slower in rock . Unlike the P - wave , the S - wave can not travel through the molten outer core of the Earth , and this causes a shadow zone for S - waves opposite to where they originate . They can still appear in the solid inner core : when a P - wave strikes the boundary of molten and solid cores , S - waves will then propagate in the solid medium . And when the S - waves hit the boundary again they will in turn create P - waves . This property allows seismologists to determine the nature of the inner core . </P>
s waves can not travel through which part of the earth
s waves can not travel through which part of the earth
the molten outer core of the Earth
the molten outer core of the Earth