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EARTTHQUAKE WAVES, , “The study of the passage of seismic (earth quack) waves through ", the earth have helped greatly in knowing the interior of the earth. plelam S mie wee, , Sand, waves felt, , , , , , , , , , + The earth waves changes its behavior as it pass different, boundaries of different zones. Their velocity differ in solid and liquid, zone., , + The earthquake waves suffer reflection and refraction when they, , travel through different media aly P, , ae, , Timing and strength, of seismic waves, S waves absorbed gives us a picture of, , the interior., , bourlary, , + Density and velocity increase with depth with sudden increase at, the average depth of 33km ~ boundary of crust and mantle called, Mohorovicic discontinuity, , + and continue this process further until up to the depth of 2,900km., boundary of mantle and outer core called, , Gutenberg discontinuity Velocity decrease from here, showing molten layer as the S-waves disappear here., , , , , , , , * The velocity increase again from the depth of, 5150 km. (> boundary between outer core and inner eee, , core) which show solid inner core and continues till the Cer’ crust & upper, " Repiti discontinuity ees | om, , , , of the earth 6371km. mantle, , | between upper &, + METEORS reaching earth from space which are ower Mant, formed in the same way as the earth shows in their, cross section, layered structure and similar layers that, are supposed to be found in the interior of the earth., , Guttenberg, , discontinuity, between lower, Mantle & outer Core, , , , Lehmann discontinuity, between outer &, , Fig. Earth's internal avers and thier boundaries (modified by Pomasi=)