jälkijäristykset

Jälkijäristykset, often referred to as aftershocks, are seismic events that occur after a larger earthquake, known as the mainshock. They are essentially smaller earthquakes that originate in the same region as the mainshock, following the rupture and stress readjustment of the Earth's crust. These aftershocks are a natural consequence of the mainshock's seismic activity.

The intensity and frequency of aftershocks vary greatly. The largest aftershock is typically weaker than the mainshock, but can still be strong enough to cause significant damage, especially if structures have already been weakened by the initial earthquake. The number of aftershocks can range from a few to hundreds or even thousands, and they can continue for days, weeks, months, or even years after the main event, though their intensity and frequency generally decrease over time.

Scientists monitor aftershocks to understand the complex processes occurring within the Earth's crust after an earthquake. The distribution and timing of aftershocks can provide valuable information about the extent of the fault rupture and the distribution of stress in the region. While often less destructive than the mainshock, aftershocks pose a significant hazard to affected populations, as they can trigger further damage to already vulnerable buildings and infrastructure, and can cause additional fear and disruption.