Final answer:
The seismograms for strong earthquakes will show larger wave amplitudes compared to weak earthquakes. P-waves arrive before S-waves due to their higher travel speed. The precision of determining the source of an earthquake depends on the timing accuracy of seismographs and the known speeds of seismic waves.
Step-by-step explanation:
Comparison of Seismograms for Strong and Weak Earthquakes:
A seismograph records seismic activity as a seismogram, which depicts the waveforms of seismic waves. For a strong earthquake, the seismogram would show larger amplitude waves that denote a higher energy release compared to a weak earthquake. The arrival times of the primary waves (P-waves) and secondary waves (S-waves) would also differ on the seismogram; however, the P-waves would always arrive before the S-waves due to their higher speed of travel through the Earth's interior. P-waves have speeds of 4 to 7 km/s and S-waves have speeds of 2 to 5 km/s, but both are faster in more rigid materials like granite.
Regarding the precise determination of the earthquake source, if S- and P-waves travel at 4.00 and 7.20 km/s respectively, and the precision of the seismograph's time recording is 0.100 s, then the uncertainty in the distance to the earthquake's epicenter can be calculated based on the differential travel time of the waves. The uncertainty increases if there is also uncertainty in the propagation speeds of the waves.
For the seismic waves from underground detonations of nuclear bombs, precise location of the test site and detection of test bans is also dependent on the precision of the seismograph and the known speeds of P- and S-waves in the region, indicating that limits in precision and the propagation speed uncertainties can affect the detection capabilities.