QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Diablo, CA

Yes. A magnitude 1.9 earthquake was recorded 4 km (2 mi) N of Diablo, CA, at 2:53 pm PDT on 3 September 2016 (21:53 UTC), 11 km deep.

This was on 3 September 2016. The latest near Diablo: M 3.0 on 14 September 2026.

USGS: 3 km N of Diablo, California

8 km (5 mi) ESE of Walnut Creek, CA · 41 km (26 mi) ENE of San Francisco, CA

2:53 pm PDT, Sep 3, 2016 · · 11 km deep · released about 25 lb of TNT

10 km30 km60 km120 km N Contra Costa County 6 kmAlameda County 25 kmSolano County 44 kmSan Joaquin County 61 kmSan Mateo County 62 kmMarin County 72 kmSanta Clara County 76 kmNapa County 78 kmSacramento County 84 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
2:53 pm PDT on 3 September 2016 ()
Where
4 km (2 mi) N of Diablo, CA · earthquakes near Diablo
Magnitude
M 1.9 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 6 km N
Nearest mapped fault
Calaveras fault, 7 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 11 km (7 mi) from the epicentre. In Diablo, 4 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: Diablo 4 km, intensity II · Danville 6 km, intensity II · Alamo 7 km, intensity II · Blackhawk 7 km, intensity II · Clayton 8 km, intensity II · Walnut Creek 10 km, intensity II · San Ramon 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 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 The 2014 South Napa, California Earthquake · 49 km NW of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 17 km E of this epicentre
  3. 5.7 15 km NE of East Foothills, California · 50 km SSE of this epicentre
  4. 5.4 South of Elmira, California · 48 km N of this epicentre
  5. 5.4 9 km NE of Livermore, California · 26 km ESE 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 37.8702, -121.9615. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 6 km (3 mi) N earthquakes near Contra Costa County
Alameda County, CA 25 km (16 mi) S earthquakes near Alameda County
Solano County, CA 44 km (27 mi) N earthquakes near Solano County
San Joaquin County, CA 61 km (38 mi) E earthquakes near San Joaquin County
San Mateo County, CA 62 km (39 mi) SW earthquakes near San Mateo County
Marin County, CA 72 km (45 mi) WNW earthquakes near Marin County

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

Aftershocks so far

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

  1. 1.9 1 km WSW of Concord, California
  2. 2.3 8 km SE of Livermore, California
  3. 1.6 1 km NW of Acalanes Ridge, California
  4. 1.5 1 km NNW of Piedmont, California
  5. 2.2 0 km NW of Piedmont, California
  6. 2.3 1 km NW of Piedmont, California
  7. 1.9 10 km N of East Foothills, California
  8. 1.6 3 km SSW of Alamo, California
  9. 1.6 10 km NNE of East Foothills, California
  10. 1.7 1 km SSE of East Richmond Heights, California
  11. 1.7 10 km SW of Brentwood, California
  12. 1.6 6 km SE of Sunol, California
  13. 1.5 2 km SSE of Pleasanton, California
  14. 1.6 9 km NNE of East Foothills, California
  15. 1.8 3 km W of Orinda, 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.