The earthquakes are caused by:
Rocks which are firmly attached to each other inside of the crust of the earth surface suddenly moving adjacent to the fault line.
Rocks which are firmly attached to each other inside of the crust of the earth surface suddenly moving adjacent to the fault line.
The intensity of an earthquake is how much the ground shakes at a certain point due to an earthquake. The intensity is classified into 10 stages in Japan.
| Intensity | |
|---|---|
| 0 | People do not feel the ground motion. |
| 1 | People inside of buildings feel the ground motion slightly. |
| 2 | Many people inside of buildings feel the ground motion. |
| 3 | Most people inside of buildings feel the ground motion |
| 4 | Suspended objects shake violently. |
| 5(lower) | Dishes fall from shelves. |
| 5(upper) | Heavy furniture and gravestones move and the water pipes can be damaged. |
| 6(lower) | The windows of buildings fall out and cracks in the ground and landslides occur. |
| 6(upper) | People cannot stand. |
| 7 | People cannot stand and buildings with weak earthquake resistance are demolished or collapse. |
The magnitude is the value calculated by estimating the total amount of energy released during the earthquake.
The moment magnitude is the value where the long-period ground motion is considered for the magnitude calculation method.