M4.0 Earthquake 10 km ENE of Coso Junction, CA — August 23, 2026
2026-08-23 07:59:55 UTC (58 min ago) · approx. 11:59 PM UTC-8 local
On August 23, 2026 at 07:59 UTC, a magnitude 4.0 shallow crustal earthquake struck 10 km ENE of Coso Junction, CA, at a depth of 2.2 km and coordinates 36.0697°, -117.8413°. The earthquake was reported felt by 4 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.4 (moderate).
Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 13 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 327 m — a useful intuition for the size of the slip patch on the fault.
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 4 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-117.8413°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.0 earthquake near Coso Junction, CA?
The magnitude 4.0 earthquake that struck 10 km ENE of Coso Junction, CA on August 23, 2026 at 07:59 UTC had a depth of 2.2 km. It was felt by 4 people with maximum shaking intensity of MMI 4.4 (moderate). For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.0 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: ci41533416). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, August 23, 2026). M4.0 Earthquake 10 km ENE of Coso Junction, CA — August 23, 2026. Retrieved August 23, 2026 from https://www.earthquaketracker.org/earthquakes/event/ci41533416/