QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Berkeley, CA

No earthquake was likely felt in Berkeley in the 24 hours to 7:49 am PST (15:49 UTC). The last one was M 1.6, 2 km (2 mi) E, at 6:31 pm PST on 1 November 2026, estimated intensity II (weak) in town. Every earthquake near Berkeley

This page: a magnitude 1.8 earthquake was recorded 3 km (2 mi) east-southeast of Berkeley, CA, at 6:50 pm PST on 6 December 2020 (02:50 UTC), 8.7 km deep.

USGS: 3km ESE of Berkeley, CA

18 km (11 mi) ENE of San Francisco, CA · in Berkeley, CA

6:50 pm PST, Dec 6, 2020 · · 8.7 km deep · released about 14 lb of TNT

10 km30 km60 km120 km N Contra Costa County 26 kmAlameda County 38 kmMarin County 49 kmSan Mateo County 51 kmSolano County 52 kmSan Francisco County 71 kmNapa County 72 kmSan Joaquin County 86 kmSanta Clara 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
6:50 pm PST on 6 December 2020 ()
Where
3 km (2 mi) east-southeast of Berkeley, CA · earthquakes near Berkeley
Magnitude
M 1.8 (md)
Depth
8.7 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 26 km ENE
Nearest mapped fault
Hayward fault, under 1 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 2156 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 Berkeley, 3 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: Berkeley 3 km, intensity II · Orinda 6 km, intensity II · Oakland 7 km, intensity II · El Cerrito 8 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 30 km WSW of this epicentre
  2. 6.0 The 2014 South Napa, California Earthquake · 39 km N of this epicentre
  3. 5.8 The 1980 Livermore, California Earthquake · 42 km E of this epicentre
  4. 5.4 9 km NE of Livermore, California · 49 km ESE of this epicentre
  5. 5.3 The 1957 San Francisco, California Earthquake · 30 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 37.8640, -122.2440. 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 38 km (24 mi) SE earthquakes near Alameda County
Marin County, CA 49 km (30 mi) WNW earthquakes near Marin County
San Mateo County, CA 51 km (32 mi) SSW earthquakes near San Mateo County
Solano County, CA 52 km (32 mi) NNE earthquakes near Solano County
San Francisco County, CA 71 km (44 mi) WSW earthquakes near San Francisco 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. 2.3 2km SE of Danville, CA
  2. 1.8 2km ESE of Berkeley, CA
  3. 2.6 1km ENE of Union City, CA
  4. 2.2 3km SW of Green Valley, CA
  5. 1.6 8km ESE of Fremont, CA
  6. 1.8 4km NE of Pleasanton, CA
  7. 2.7 8km ESE of Fremont, CA
  8. 2.0 0km SE of Pleasant Hill, CA
  9. 2.1 8km ESE of Fremont, CA
  10. 1.5 3km ESE of Berkeley, CA
  11. 2.6 3km ESE of Berkeley, CA
  12. 2.1 2km WNW of Castro Valley, CA
  13. 1.9 2km NW of Orinda, CA
  14. 1.7 9km NW of San Francisco Zoo, CA
  15. 2.0 5km SW of Danville, 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.