QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near San Ramon, CA

No earthquake was likely felt in San Ramon in the 24 hours to 11:54 pm PST (07:54 UTC). The last one was M 2.1, 6 km (4 mi) NNE, at 7:18 am PDT on 31 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near San Ramon

This page: a magnitude 1.7 earthquake was recorded 7 km (4 mi) west of San Ramon, CA, at 4:49 pm PDT on 14 October 2017 (23:49 UTC), 14 km deep.

USGS: 7 km W of San Ramon, California

15 km (9 mi) E of Oakland, CA · 11 km (7 mi) W of San Ramon, CA

4:49 pm PDT, Oct 14, 2017 · · 14 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N Alameda County 19 kmContra Costa County 19 kmSan Mateo County 48 kmSolano County 56 kmMarin County 68 kmSanta Clara County 69 kmSan Joaquin County 71 kmSanta Cruz County 84 kmNapa 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
4:49 pm PDT on 14 October 2017 ()
Where
7 km (4 mi) west of San Ramon, CA · earthquakes near San Ramon
Magnitude
M 1.7 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Alameda County, 19 km SE
Nearest mapped fault
Calaveras fault, 6 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 3311 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In San Ramon, 7 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.

Earthquakes near other towns within 30 km: Danville, Castro Valley, Alamo, Moraga, Ashland, San Leandro.

How big was it?

This earthquake released about 11 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 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.9 The 1906 San Francisco, California Earthquake · 43 km W of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 27 km ENE of this epicentre
  3. 5.7 15 km NE of East Foothills, California · 46 km SE of this epicentre
  4. 5.5 6 km NNE of East Foothills, California · 45 km SE of this epicentre
  5. 5.4 9 km NE of Livermore, California · 31 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 37.7707, -122.0573. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 19 km (12 mi) SE earthquakes near Alameda County
Contra Costa County, CA 19 km (12 mi) NNE earthquakes near Contra Costa County
San Mateo County, CA 48 km (30 mi) SW earthquakes near San Mateo County
Solano County, CA 56 km (35 mi) N earthquakes near Solano County
Marin County, CA 68 km (42 mi) WNW earthquakes near Marin County
Santa Clara County, CA 69 km (43 mi) SSE earthquakes near Santa Clara 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. 1.6 10km NNE of Alum Rock, CA
  2. 1.7 4km SW of Stanford, CA
  3. 2.3 3km N of San Leandro, CA
  4. 1.5 5km E of Vallejo, CA
  5. 1.9 3km N of San Leandro, CA
  6. 2.4 2km E of Berkeley, CA
  7. 1.5 9km SE of Livermore, CA
  8. 1.6 2km E of Hayward, CA
  9. 4.4 2km SE of Berkeley, CA
  10. 3.9 8km ENE of Alum Rock, CA
  11. 2.7 0km SW of Pacheco, CA
  12. 1.5 8km SSE of Rio Vista, CA
  13. 2.3 2km NW of Pittsburg, CA
  14. 1.6 5km NNW of Pacifica, CA
  15. 2.2 5km NNW of Pacifica, 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.