QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Brentwood, CA

Yes. A magnitude 1.7 earthquake was recorded 11 km (7 mi) SW of Brentwood, CA, at 6:32 pm PST on 21 November 2016 (02:32 UTC), 20 km deep.

This was on 21 November 2016. The latest near Brentwood: M 3.0 on 14 September 2026.

USGS: 10 km SW of Brentwood, California

10 km (6 mi) SSW of Brentwood, CA · 63 km (39 mi) N of San Jose, CA

6:32 pm PST, Nov 21, 2016 · · 20 km deep · released about 11 lb of TNT

Every earthquake near Brentwood Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 17 kmAlameda County 26 kmSan Joaquin County 45 kmSolano County 48 kmSanta Clara County 71 kmSan Mateo County 72 kmStanislaus County 76 kmSacramento County 76 kmNapa County 87 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
6:32 pm PST on 21 November 2016 ()
Where
11 km (7 mi) SW of Brentwood, CA · earthquakes near Brentwood
Magnitude
M 1.7 (md)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 17 km WNW
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 it was probably too small to be felt, even directly above it. In Brentwood, 11 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.

Earthquakes near other towns within 30 km: Byron, Blackhawk, Knightsen, Diablo, Discovery Bay, Oakley.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 · 2 km SSE of this epicentre
  2. 5.7 15 km NE of East Foothills, California · 43 km S of this epicentre
  3. 5.5 6 km NNE of East Foothills, California · 47 km S of this epicentre
  4. 5.4 9 km NE of Livermore, California · 14 km SSE of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 5 km S 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 37.8587, -121.7757. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 17 km (10 mi) WNW earthquakes near Contra Costa County
Alameda County, CA 26 km (16 mi) SSW earthquakes near Alameda County
San Joaquin County, CA 45 km (28 mi) E earthquakes near San Joaquin County
Solano County, CA 48 km (30 mi) NNW earthquakes near Solano County
Santa Clara County, CA 71 km (44 mi) S earthquakes near Santa Clara County
San Mateo County, CA 72 km (45 mi) SW earthquakes near San Mateo County

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

Aftershocks so far

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

  1. 1.8 10 km NNE of East Foothills, California
  2. 1.7 1 km W of Diablo, California
  3. 2.0 5 km WSW of Martinez, California
  4. 1.7 4 km S of Pittsburg, California
  5. 1.9 6 km W of Country Club, California
  6. 1.5 1 km S of Livermore, California
  7. 2.1 8 km N of East Foothills, California
  8. 2.8 8 km SE of Livermore, California
  9. 1.6 2 km ESE of Waldon, California
  10. 1.8 9 km SW of Brentwood, California
  11. 1.5 0 km NW of Concord, California
  12. 1.8 5 km NE of East Foothills, California
  13. 2.1 12 km ESE of Elmira, California
  14. 1.6 1 km S of Pacheco, California
  15. 2.2 1 km E of Pacheco, 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.