SOLAR SYSTEM

Detailed explanation-1: -Evidence for a fluid outer core includes seismology which shows that seismic shear-waves are not transmitted through the outer core. Although having a composition similar to Earth’s solid inner core, the outer core remains liquid as there is not enough pressure to keep it in a solid state.

Detailed explanation-2: -7.4 shows wave propagation through Earth. Note that P waves pass through all layers of the earth, while S waves cannot pass through the solid core of the earth, resulting in an S wave shadow on the opposite side of the earthquake.

Detailed explanation-3: -Figure 19.2b: S-waves do not travel through the outer core, creating an even bigger shadow zone for S-waves. The fact that S-waves do not travel through the outer core suggests that the latter is liquid.

Detailed explanation-4: -S-waves are stopped by the liquid outer core, and P-waves are refracted as they enter and leave the liquid outer core. Additional data from the study of many earthquakes has shown scientists that the rate at which P-waves and S-waves move depends upon the type and density of the material through which they travel.