QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Piedmont, CA

No earthquake was likely felt in Piedmont in the 24 hours to 4:20 am PST (12:20 UTC). The last one was M 2.6, 5 km (3 mi) NNW, at 6:23 pm PST on 1 November 2026, estimated intensity III (weak) in town; 114 felt reports to USGS. Every earthquake near Piedmont

This page: a magnitude 1.9 earthquake was recorded in Piedmont, CA, at 6:49 am PDT on 6 June 2025 (13:49 UTC), 5.2 km deep. 12 people have reported feeling it to USGS.

USGS: 2 km ESE of Piedmont, CA

6 km (4 mi) N of Oakland, CA

6:49 am PDT, Jun 6, 2025 · · 5.2 km deep · released about 22 lb of TNT

10 km30 km60 km120 km N Contra Costa County 26 kmAlameda County 33 kmSan Mateo County 47 kmMarin County 53 kmSolano County 55 kmSan Francisco County 73 kmNapa County 77 kmSanta Clara County 81 kmSan Joaquin 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
6:49 am PDT on 6 June 2025 ()
Where
in Piedmont, CA · earthquakes near Piedmont
Magnitude
M 1.9 (md)
Depth
5.2 km below the surface
Felt
12 reports · strongest reported intensity II
Nearest
Contra Costa County, 26 km ENE
Nearest mapped fault
Hayward fault, 2 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 520 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 14 km (9 mi) from the epicentre. 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: Oakland 5 km, intensity II · Alameda 7 km, intensity II · Orinda 7 km, intensity II · Berkeley 8 km, intensity II · Lafayette 11 km, intensity II · San Leandro 12 km, intensity II · El Cerrito 14 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 22 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 5.8 680,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 480,000× the energy of this one
  3. Around the size people start to feel M 3.0 43× the energy of this one
  4. This earthquake M 1.9 about 22 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

The largest earthquake within 50 km since 2016 was M 4.5 on 2019-10-15 — about 6,700 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 31 km WSW of this epicentre
  2. 6.0 The 2014 South Napa, California Earthquake · 45 km N of this epicentre
  3. 5.8 The 1980 Livermore, California Earthquake · 39 km E of this epicentre
  4. 5.4 9 km NE of Livermore, California · 45 km E of this epicentre
  5. 5.3 The 1957 San Francisco, California Earthquake · 29 km SW 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 37.8203, -122.2135. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 26 km (16 mi) ENE earthquakes near Contra Costa County
Alameda County, CA 33 km (20 mi) SE earthquakes near Alameda County
San Mateo County, CA 47 km (29 mi) SSW earthquakes near San Mateo County
Marin County, CA 53 km (33 mi) WNW earthquakes near Marin County
Solano County, CA 55 km (34 mi) NNE earthquakes near Solano County
San Francisco County, CA 73 km (45 mi) W earthquakes near San Francisco County

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

Aftershocks so far

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

  1. 1.7 2 km E of Hayward, CA
  2. 2.0 2 km ENE of Berkeley, CA
  3. 1.9 7 km ESE of Black Point-Green Point, CA
  4. 1.9 3 km SW of Clayton, CA
  5. 2.6 3 km ESE of Berkeley, CA
  6. 1.9 5 km WSW of San Francisco Zoo, CA
  7. 1.6 3 km SW of Clayton, CA
  8. 1.7 2 km ENE of Pacheco, CA
  9. 1.6 6 km ENE of Vallejo, CA
  10. 1.6 2 km NW of Concord, CA
  11. 1.9 5 km SSE of Pittsburg, CA
  12. 2.3 1 km N of Sunol, CA
  13. 2.5 2 km NW of Woodside, CA
  14. 1.8 6 km NW of San Francisco Zoo, CA
  15. 2.0 2 km SW of Oakland, CA

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.