On average, a magnitude 6.4 earthquake will produce an aftershock as large as what was experienced early Friday, and about 10 aftershocks with a magnitude 4.4 or larger. Earthquakes of this size can cause damage, particularly close to the epicenter, according to the USGS.
It’s also likely there will be smaller quakes into next week, with 50 to 700 aftershocks rolling in at magnitude 3 or higher, officials said. Magnitude 3 and above are large enough to be felt near the epicenter. USGS estimates a 9% chance of one or more aftershocks of magnitude 6.4 or greater in the next week.
An average of five earthquakes with magnitudes between 5.0 and 6.0 occur each year in California and Nevada, according to a recent three-year data sample. Before Thursday, it had been almost five years since the state experienced an earthquake of magnitude 6.0 or stronger. Experts had said the period of calm was sure to end, and when it did, it would likely bring destruction.
Stay safe and make sure you have an action plan! -Vanessa J