Aftershock Events: Understanding, Preparing for, and Staying Safe After Earthquakes

What Are Aftershocks?

Aftershocks are smaller earthquakes that occur in the same region following a larger mainshock. They result from the Earth’s crust readjusting to changes caused by the main earthquake.

Key Facts About Aftershocks

• Can continue for weeks, months, or even years after the main quake
• Typically less powerful than the mainshock (but can still be dangerous)
• Follow the “Omori’s Law” pattern – frequency decreases over time
• May cause additional damage to already weakened structures