Southern California Earthquakes Today

Where to check today's activity

Earthquakes in Southern California are located by the Southern California Seismic Network, which is run jointly by Caltech and the USGS in Pasadena. Its hundreds of stations feed the USGS national catalog within minutes, so the same events appear on several sites. These are the most reliable places to look:

• The EQRadar live map, centered on Southern California, which displays USGS-reported earthquakes and lets you tap an event for details.
• The USGS Latest Earthquakes map, the official national listing.
• The SCSN website, which adds regional catalogs and background on local faults.
• The earthquake history view if you want to compare today with past weeks or years in the same area.

How to read what you see

Each listing gives a time, a Magnitude, a location and a Depth. Times are often shown in Coordinated Universal Time (UTC). Southern California is 8 hours behind UTC in winter and 7 hours behind during daylight saving time, so an event at 03:00 UTC happened the previous evening locally. Most local earthquakes are shallow, usually less than about 15 kilometers deep, which is one reason even moderate ones are felt strongly.

Pay attention to the review status. A brand-new event is marked automatic: computers picked the arrival times and estimated the size. Within minutes to hours a seismologist reviews it, and the magnitude may move up or down by a few tenths, or the location may shift slightly. That is normal. Larger events often get a ShakeMap showing estimated shaking across the region.

Why Southern California shakes so often

Southern California sits on the boundary between the Pacific and North American plates. Instead of a single crack, the boundary is a wide zone of many faults that together take up the plates' sliding motion. The San Andreas Fault is the biggest, running from the Salton Sea through the Coachella Valley, along the San Bernardino Mountains and across the Tejon Pass area. Parallel to it lie the San Jacinto and Elsinore fault zones, which are also very active.

Near the coast and under the Los Angeles basin are faults that are harder to see, including the Newport-Inglewood fault and hidden thrust faults such as the Puente Hills thrust beneath downtown Los Angeles. In the Mojave Desert, a band of faults called the Eastern California Shear Zone has produced several large earthquakes in recent decades. The east-west Garlock fault marks the northern edge of the Mojave. For an overview, see what causes earthquakes in California.

Notable past earthquakes

History shows that damaging earthquakes can come from many different faults, not only the San Andreas. The table lists some of the best-known events, with approximate magnitudes.

Local hazards beyond shaking

Shaking is the main hazard, but it is not the only one. Loose, water-soaked sediments in river valleys, along the coast and in parts of the Los Angeles basin can undergo Liquefaction, which can tilt buildings and break pipes. The steep mountains that ring the basins are prone to landslides and rockfalls, especially after wet winters. Coastal communities face a Tsunami hazard, mostly from very large earthquakes elsewhere around the Pacific; offshore faults could also produce local waves. The California Geological Survey publishes maps of liquefaction, landslide and tsunami zones.

Basins filled with deep sediment, like the Los Angeles and San Fernando valleys, can amplify and prolong shaking. That is part of why the effects of a given earthquake can vary a lot from one neighborhood to the next.

Early warning and alerts

California is covered by ShakeAlert, the USGS earthquake early warning system. When it detects an earthquake already under way, it can send alerts through Wireless Emergency Alerts, the state's MyShake app and Android phones, sometimes giving a few seconds of warning before strong shaking arrives. It does not predict earthquakes. Read more in our ShakeAlert guide.

EQRadar offers in-app alerts for places you save, but they only work while the page is open in your browser, and EQRadar does not send text messages, email or push notifications.

If you felt shaking

If you feel strong shaking, Drop, Cover and Hold On until it stops. Afterward, check yourself and others for injuries, look for hazards such as gas leaks or damaged walls, and expect aftershocks. Then file a report with USGS Did You Feel It? Your report helps scientists map how strongly the earthquake was felt, even for small events. After a larger quake, the USGS often publishes an aftershock forecast, which you can find on our risk page.

Frequently asked questions