QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Clayton, CA

Yes. A magnitude 1.6 earthquake was recorded 10 km (6 mi) ESE of Clayton, CA, at 3:15 am PDT on 25 September 2016 (10:15 UTC), 3.8 km deep.

This was on 25 September 2016. The latest near Clayton: M 3.0 on 14 September 2026.

USGS: 10 km ESE of Clayton, California

8 km (5 mi) SSW of Antioch, CA · 54 km (33 mi) ENE of San Francisco, CA

3:15 am PDT, Sep 25, 2016 · · 3.8 km deep · released about 6.4 lb of TNT

10 km30 km60 km120 km N Contra Costa County 11 kmAlameda County 30 kmSolano County 41 kmSan Joaquin County 49 kmSan Mateo County 73 kmSacramento County 74 kmSanta Clara County 77 kmNapa County 80 kmMarin County 82 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
3:15 am PDT on 25 September 2016 ()
Where
10 km (6 mi) ESE of Clayton, CA · earthquakes near Clayton
Magnitude
M 1.6 (md)
Depth
3.8 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 11 km W
Nearest mapped fault
Greenville fault, 4 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3531 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In Clayton, 10 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Clayton 10 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 6.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.6 about 6.4 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 5.8 The 1980 Livermore, California Earthquake · 9 km SE of this epicentre
  2. 5.7 15 km NE of East Foothills, California · 49 km SSE of this epicentre
  3. 5.4 South of Elmira, California · 44 km N of this epicentre
  4. 5.4 9 km NE of Livermore, California · 21 km SSE of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 12 km SSE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 37.9083, -121.8285. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 11 km (7 mi) W earthquakes near Contra Costa County
Alameda County, CA 30 km (19 mi) SSW earthquakes near Alameda County
Solano County, CA 41 km (26 mi) NNW earthquakes near Solano County
San Joaquin County, CA 49 km (30 mi) E earthquakes near San Joaquin County
San Mateo County, CA 73 km (45 mi) SW earthquakes near San Mateo County
Sacramento County, CA 74 km (46 mi) NE earthquakes near Sacramento County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

59 earthquakes have been recorded within 50 km since this one.

  1. 2.5 3 km NNW of Piedmont, California
  2. 1.7 20 km SE of Livermore, California
  3. 1.7 1 km E of North Gate, California
  4. 1.6 8 km NE of Milpitas, California
  5. 1.8 9 km ENE of Blackhawk, California
  6. 1.7 5 km SW of Alamo, California
  7. 1.6 1 km SSW of Concord, California
  8. 1.6 0 km S of Concord, California
  9. 2.2 1 km SW of Concord, California
  10. 2.0 3 km SSE of Piedmont, California
  11. 1.7 0 km SSE of Concord, California
  12. 2.4 3 km ENE of Vallejo, California
  13. 1.8 2 km E of Berkeley, California
  14. 2.6 2 km SSW of Alamo, California
  15. 1.6 2 km ENE of San Leandro, California

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.