Question 30
Read the following nomogram carefully.
This nomogram can be used to estimate magnitude of earthquake. P is the arrival time of P-wave (longitudinal seismic wave) and S is the arrival of S-wave (Transversal seismic wave). The above nomogram shows that the magnitude of earthquake in Richter Scale is 5. If it was recorded at the seismogram that the P-wave arrived at 07:19:19 and the S-wave at 07:19:49 with amplitude 50 mm.
a. Find the magnitude of the earthquake. (Score: 4)
b. How could you classify the earthquake according to the following classification? (Score: 1)
| Class | Magnitude |
| --- | --- |
| Great | 8 or more |
| Major | 7–7.9 |
| Strong | 6–6.9 |
| Moderate | 5–5.9 |
| Light | 4–4.9 |
| Minor | 3–3.9 |
This nomogram can be used to estimate magnitude of earthquake. P is the arrival time of P-wave (longitudinal seismic wave) and S is the arrival of S-wave (Transversal seismic wave). The above nomogram shows that the magnitude of earthquake in Richter Scale is 5. If it was recorded at the seismogram that the P-wave arrived at 07:19:19 and the S-wave at 07:19:49 with amplitude 50 mm.
a. Find the magnitude of the earthquake. (Score: 4)
b. How could you classify the earthquake according to the following classification? (Score: 1)
| Class | Magnitude |
| --- | --- |
| Great | 8 or more |
| Major | 7–7.9 |
| Strong | 6–6.9 |
| Moderate | 5–5.9 |
| Light | 4–4.9 |
| Minor | 3–3.9 |