QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Dublin, CA

No earthquake was likely felt in Dublin in the 24 hours to 1:29 am PST (09:29 UTC). The last one was M 1.9, 5 km (3 mi) SW, at 10:32 am PST on 2 November 2026, estimated intensity II (weak) in town. Every earthquake near Dublin

This page: a magnitude 1.7 earthquake was recorded 4 km (2 mi) west-northwest of Dublin, CA, at 6:16 pm PST on 17 December 2020 (02:16 UTC), 10.0 km deep.

USGS: 4km WNW of Dublin, CA

7 km (4 mi) W of Dublin, CA · 40 km (25 mi) E of San Francisco, CA

6:16 pm PST, Dec 17, 2020 · · 10.0 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Alameda County 9 kmContra Costa County 23 kmSan Mateo County 48 kmSanta Clara County 60 kmSolano County 62 kmSan Joaquin County 67 kmMarin County 77 kmSanta Cruz County 78 kmStanislaus 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
6:16 pm PST on 17 December 2020 ()
Where
4 km (2 mi) west-northwest of Dublin, CA · earthquakes near Dublin
Magnitude
M 1.7 (md)
Depth
10.0 km below the surface
Felt
no reports yet
Nearest
Alameda County, 9 km SE
Nearest mapped fault
Calaveras fault, 3 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 2144 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. In Dublin, 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: Dublin 4 km, intensity II · San Ramon 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 12 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 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× the energy of this one
  4. This earthquake M 1.7 about 12 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 12,000 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 Near San Jose, California · 48 km SSE of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 23 km NE of this epicentre
  3. 5.7 15 km NE of East Foothills, California · 36 km SE of this epicentre
  4. 5.5 6 km NNE of East Foothills, California · 36 km SSE of this epicentre
  5. 5.4 9 km NE of Livermore, California · 24 km E 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 37.7113, -121.9760. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 9 km (6 mi) SE earthquakes near Alameda County
Contra Costa County, CA 23 km (14 mi) N earthquakes near Contra Costa County
San Mateo County, CA 48 km (30 mi) SW earthquakes near San Mateo County
Santa Clara County, CA 60 km (37 mi) SSE earthquakes near Santa Clara County
Solano County, CA 62 km (38 mi) N earthquakes near Solano County
San Joaquin County, CA 67 km (41 mi) ENE earthquakes near San Joaquin 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. 1.6 8km ESE of Fremont, CA
  2. 1.8 4km NE of Pleasanton, CA
  3. 2.7 8km ESE of Fremont, CA
  4. 1.9 6km N of Alum Rock, CA
  5. 2.0 0km SE of Pleasant Hill, CA
  6. 2.1 8km ESE of Fremont, CA
  7. 2.0 11km NE of Milpitas, CA
  8. 1.6 11km NE of Milpitas, CA
  9. 1.6 10km NE of Milpitas, CA
  10. 1.5 10km NE of Milpitas, CA
  11. 1.8 10km NE of Milpitas, CA
  12. 3.2 10km NE of Milpitas, CA
  13. 2.0 9km E of Alum Rock, CA
  14. 1.5 3km ESE of Berkeley, CA
  15. 2.6 3km ESE of Berkeley, 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.