QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Fremont, CA

No earthquake was likely felt in Fremont in the 24 hours to 12:03 am PST (08:03 UTC). The last one was M 3.5, 49 km (31 mi) ESE, at 7:21 am PDT on 27 September 2026, estimated intensity II (weak) in town; 8 felt reports to USGS. Every earthquake near Fremont

This page: a magnitude 1.7 earthquake was recorded 6 km (4 mi) east of Fremont, CA, at 5:22 pm PST on 14 February 2018 (01:22 UTC), 5.5 km deep.

USGS: 6km E of Fremont, CA

5 km (3 mi) NNE of Fremont, CA

5:22 pm PST, Feb 14, 2018 · · 5.5 km deep · released about 10 lb of TNT

Every earthquake near Fremont Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 12 kmSanta Clara County 41 kmSan Mateo County 42 kmContra Costa County 43 kmSanta Cruz County 59 kmSan Joaquin County 72 kmStanislaus County 81 kmSolano County 81 kmMarin County 92 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
5:22 pm PST on 14 February 2018 ()
Where
6 km (4 mi) east of Fremont, CA · earthquakes near Fremont
Magnitude
M 1.7 (md)
Depth
5.5 km below the surface
Felt
no reports yet
Nearest
Alameda County, 12 km N
Nearest mapped fault
Hayward fault, 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 3192 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 11 km (7 mi) from the epicentre. In Fremont, 6 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: Fremont 6 km, intensity II · Newark 11 km, intensity II · Union City 11 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 10 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 1,500,000× 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 92× the energy of this one
  4. This earthquake M 1.7 about 10 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 4.4 on 2018-01-04 — about 11,000 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 Near San Jose, California · 28 km SSE of this epicentre
  2. 6.2 The 1984 Morgan Hill, California Earthquake · 33 km SE of this epicentre
  3. 6.1 Near San Jose, California · 39 km SSE of this epicentre
  4. 5.8 7 km NNW of Boulder Creek, California · 44 km SSW of this epicentre
  5. 5.8 The 1980 Livermore, California Earthquake · 36 km NNE 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 37.5377, -121.9190. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 12 km (8 mi) N earthquakes near Alameda County
Santa Clara County, CA 41 km (25 mi) SSE earthquakes near Santa Clara County
San Mateo County, CA 42 km (26 mi) WSW earthquakes near San Mateo County
Contra Costa County, CA 43 km (26 mi) N earthquakes near Contra Costa County
Santa Cruz County, CA 59 km (37 mi) S earthquakes near Santa Cruz County
San Joaquin County, CA 72 km (45 mi) NE earthquakes near San Joaquin County

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

Aftershocks so far

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

  1. 2.0 6km NNE of Castro Valley, CA
  2. 1.8 14km ESE of Alum Rock, CA
  3. 1.6 2km NE of Danville, CA
  4. 2.2 6km NNE of Castro Valley, CA
  5. 2.1 6km NNE of Castro Valley, CA
  6. 1.6 4km SW of Danville, CA
  7. 1.7 2km W of Diablo, CA
  8. 1.8 2km W of Diablo, CA
  9. 1.6 2km WSW of Diablo, CA
  10. 1.6 2km SW of Diablo, CA
  11. 1.9 2km ENE of Danville, CA
  12. 2.8 2km WSW of Diablo, CA
  13. 3.5 2km ENE of Danville, CA
  14. 3.4 2km ENE of Danville, CA
  15. 1.5 2km SW of Diablo, 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.