Earthquake near Fremont, CA

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 15 km (9 mi) from the epicentre. In Fremont, 8 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 8 km, intensity II · Milpitas 12 km, intensity II · Union City 13 km, intensity II · Newark 13 km, intensity II · Pleasanton 14 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
3. Around the size people start to feel M 3.0 22× the energy of this one
4. This earthquake M 2.1 about 43 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 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 Aug 3, 1903
2. 6.2 The 1984 Morgan Hill, California Earthquake · 32 km SE of this epicentre Apr 24, 1984
3. 6.1 Near San Jose, California · 39 km SSE of this epicentre Jun 11, 1903
4. 5.8 7 km NNW of Boulder Creek, California · 45 km SSW of this epicentre Sep 5, 1955
5. 5.8 The 1980 Livermore, California Earthquake · 35 km NNE of this epicentre Jan 24, 1980

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 37.5390, -121.8952. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.0 14 km E of Seven Trees, California 02:14 UTC
2. 2.1 6 km ENE of East Foothills, California 16:01 UTC
3. 1.6 2 km ENE of San Leandro, California 19:13 UTC
4. 1.5 Northern California 22:32 UTC
5. 1.7 25 km SE of Livermore, California 19:27 UTC
6. 1.7 1 km ENE of Alamo, California 07:22 UTC
7. 1.8 3 km NNW of Castro Valley, California 07:18 UTC
8. 2.1 3 km NNW of Castro Valley, California 04:34 UTC
9. 2.4 6 km NE of East Foothills, California 13:48 UTC
10. 1.8 2 km SSE of North Gate, California 01:03 UTC
11. 1.9 3 km SE of North Gate, California 17:02 UTC
12. 2.1 15 km N of Morgan Hill, California 01:01 UTC
13. 1.7 3 km S of Loyola, California 20:24 UTC
14. 1.6 1 km SW of Blackhawk, California 12:11 UTC
15. 2.1 0 km SW of Blackhawk, California 08:11 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 10:44 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

• The official USGS event page — the source of record for every value above
• Did you feel it? Report it to USGS — reports go to USGS, not to us
• ShakeMap for this event, when USGS has produced one

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.