N | Name | Lead time | Origin place | Alarm rate | Estimated PG | Probable mechanism |
1 | Seismic foreshocks | 24 - 20 hours | Ground | ~20 - 30% | ~10 - 20 | Fracturing by WGM |
2 | Seismic acoustic pulses | 16 - 12 hours | Ground | ~70% | ~20 - 100 | Fracturing by WGM |
3 | ULF pulsating emission | 4 - 3 hours | Ground | 40 - 50% | ~1 - 5 | EKE by WGM |