Overview

• A magnitude 3.5 quake struck near Rialto on August 5 at 4:55 p.m., followed by two more 3.5-magnitude events that evening and a 3.7-magnitude aftershock near Lytle Creek overnight.
• Residents from Fontana to San Clemente and Santa Clarita reported light shaking through the USGS “Did You Feel It?” system.
• This latest tremor marks the fifth earthquake of magnitude 3.0 or greater in the past ten days clustered along the Fontana trend fault zone.
• Regional preparedness measures have helped ensure that none of the recent temblors resulted in injuries or structural damage.
• California and Nevada average 234 quakes of magnitude 3.0 to 4.0 each year, illustrating how the current swarm fits typical seismic patterns.