The correct answer is: b) P waves travel faster and thus arrive sooner than do the S waves.
Explanation: Seismic waves are generated by earthquakes and travel through the Earth in different ways. There are two primary types of seismic waves: P waves (Primary waves) and S waves (Secondary waves). P waves are compressional waves that can move through both solid and liquid materials, while S waves are shear waves that can only travel through solids. Because P waves are faster than S waves, they are the first to be detected by seismographs after an earthquake occurs. This is why we observe a clear difference in arrival times for P waves and S waves during seismic events. Options A, C, and D are incorrect because:
- Statement A is false; while S waves cannot travel through liquids, P waves can.
- Statement C is misleading; shadow zones are regions where no seismic waves are detected, but this occurs for specific reasons related to the Earth’s structure.
- Statement D is incorrect; S waves cannot travel through the outer core because it is liquid.