Antelope Valley Earthquake

August 8, 2021

6.0 MW, 15:49:48.110 PDT, Coordinates: 38.5075, -119.4998 Depth: 7.5 km

Tsunami alert level: NONE. There is no risk of tsunami from this event.
Related: U.S. Tsunami Warning System and Tsunami Hazard Area Maps for California

REPORT CONTRIBUTORS: Cindy Pridmore (CGS), Jason Patton (CGS)

UPDATED: Tuesday, July 19, 2022 5:06 PM (Pacific Time)

Overview

A Shakemap showing intensity of ground shaking produced by the earthquake. Source: Center for Engineering Strong Motion Data

A magnitude 6.0 earthquake occurred on July 8, 2021 near the town of Walker in eastern California, just after 3:49 p.m. local time. The area is sparsely populated and at this time we have no reports of damage or injuries.

Location: 33 km (20.625 mi) SE of Markleeville, CA
Magnitude: 6 MW
Date and time: 2021-08-08 3:49 p.m. (Local)
Depth: 7.5 kilometers
Sense of motion: Oblique normal (down and sideways)
Maximum measured ground acceleration: 0.262 g measured by the strong motion station at Walker (#65097)
Nearest major fault: Epicenter likely within Holocene Antelope Valley Fault Zone, part of the eastern Sierra frontal fault zone.

Felt Reports

A 'Did You Feel It?' map showing the geographic distribution of people who reported feeling the earthquake. Source: U.S. Geological Survey

This event was widely felt, lightly from Eureka to Southern California, and from San Francisco to Central Nevada. Strongest reported shaking was near epicentral area: MMI Intensity VI “felt as strong shaking.” (Source: USGS Did You Feel It?)

Aftershocks

This information is time sensitive, and more aftershocks may occur at or shortly after this report was posted.

Largest aftershock: 4.6
Number of aftershocks at time of report: 34 (range of magnitudes 1.6 to 4.6)

Future earthquakes are possible in the area but the probability decreases with time. If there is another earthquake in this area, it is likely to happen in the general vicinity of the mainshock, where most of the aftershocks are taking place, or on a nearby fault. Visit the USGS Aftershock Forecast Page for additional information.

Public Safety

Be ready: more earthquakes than usual (aftershocks) will continue to occur in the vicinity of the mainshock.

When shaking starts, remember to Drop, Cover, and Hold On.
Stay away from vulnerable structures such as unreinforced masonry buildings.
Stay away from steep slopes where rockfall may occur.
This earthquake could be part of a sequence. An earthquake sequence may have larger and potentially damaging earthquakes in the future.

Technical Information

Media Resources

Media contact: Public Affairs Office, (916) 000-0000, pao@conservation.ca.gov
Press release: None available.
Social media hashtag: #AntelopeValleyEarthquake