QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Lafayette, CA

No earthquake was likely felt in Lafayette in the 24 hours to 8:41 pm PST (04:41 UTC). The last one was M 2.1, 8 km (5 mi) NE, at 4:05 am PST on 8 November 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Lafayette

This page: a magnitude 1.8 earthquake was recorded in Lafayette, CA, at 9:42 pm PDT on 7 June 2023 (04:42 UTC), 11 km deep. 1 person has reported feeling it to USGS.

USGS: 2km N of Lafayette, CA

30 km (18 mi) ENE of San Francisco, CA · 7 km (4 mi) W of Walnut Creek, CA

9:42 pm PDT, Jun 7, 2023 · · 11 km deep · released about 15 lb of TNT

Every earthquake near Lafayette Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 15 kmAlameda County 34 kmSolano County 43 kmMarin County 57 kmSan Mateo County 59 kmNapa County 69 kmSan Joaquin County 75 kmSan Francisco County 82 kmSanta Clara County 85 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
9:42 pm PDT on 7 June 2023 ()
Where
in Lafayette, CA · earthquakes near Lafayette
Magnitude
M 1.8 (md)
Depth
11 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Contra Costa County, 15 km E
Nearest mapped fault
Concord fault, 11 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 1252 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 8 km (5 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: Lafayette in town, intensity II · Walnut Creek 5 km, intensity II · Orinda 6 km, intensity II · Pleasant Hill 7 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 10,000 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 41 km WSW of this epicentre
  2. 6.0 The 2014 South Napa, California Earthquake · 38 km NNW of this epicentre
  3. 5.8 The 1980 Livermore, California Earthquake · 32 km ESE of this epicentre
  4. 5.4 South of Elmira, California · 48 km NNE of this epicentre
  5. 5.4 9 km NE of Livermore, California · 40 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 37.9033, -122.1207. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 15 km (9 mi) E earthquakes near Contra Costa County
Alameda County, CA 34 km (21 mi) SSE earthquakes near Alameda County
Solano County, CA 43 km (27 mi) NNE earthquakes near Solano County
Marin County, CA 57 km (36 mi) WNW earthquakes near Marin County
San Mateo County, CA 59 km (36 mi) SSW earthquakes near San Mateo County
Napa County, CA 69 km (43 mi) NNW earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.8 8 km S of Byron, CA
  2. 1.5 6 km NNE of Orinda, CA
  3. 2.0 10 km SW of Brentwood, CA
  4. 2.1 10 km WSW of San Lorenzo, CA
  5. 1.7 2 km ENE of San Leandro, CA
  6. 2.0 7 km NW of San Francisco Zoo, CA
  7. 1.9 3 km ESE of South San Francisco, CA
  8. 2.0 1 km E of Pacifica, CA
  9. 2.3 1 km E of Pacifica, CA
  10. 2.2 1 km NW of Green Valley, CA
  11. 1.5 4 km ESE of Pacifica, CA
  12. 2.1 4 km NNE of Fairview, CA
  13. 2.2 2 km NW of Concord, CA
  14. 1.8 10 km ESE of Black Point-Green Point, CA
  15. 1.8 1 km ENE of Pittsburg, 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.