According to the US Geological Survey, an earthquake with a preliminary magnitude of 3.5 struck areas of San Diego County early Friday.

Little after 6:30 a.m., an earthquake struck just over a mile southeast of Palomar Observatory. Palomar Mountain, northeast of Escondido, houses the observatory.

After each recorded earthquake, the USGS’s “Did You Feel It?” map monitors accounts of shaking from all throughout the region. Residents in locations around the quake, such as Valley Center, Oceanside, Carlsbad, Encinitas, and Poway, reported “weak” and “light” shaking, according to the map.

A 3.6-magnitude earthquake struck near Julian on Monday, May 9th, while a series of lesser earthquakes struck Imperial County on Tuesday, April 19.

A “non-earthquake incident” off the coast of Catalina Island prompted a false report of a quake on April 15. The false alarm did not reach the early warning system’s magnitude 4.5 threshold, according to the USGS, thus no public alerts were issued. Officials stated that they were looking into what triggered their system and that they would learn from their mistakes.

The National Earthquake Hazards Reduction Program, which Congress established in 1977, includes the USGS Earthquake Hazards Program. “The United States Geological Survey (USGS) and its partners monitor and report earthquakes, assess earthquake impacts and hazards, and conduct research into the sources and effects of earthquakes.”

The National Earthquake Hazards Reduction Program, established by Congress in 1977, includes the USGS Earthquake Hazards Program. “The USGS and its partners monitor and report earthquakes, assess earthquake impacts and hazards, and perform research into the causes and effects of earthquakes,” the agency’s website reads.