Earthquake near San Jose, CA

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 28 km (17 mi) from the epicentre. In San Jose, 34 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: East Foothills.

How big was it?

This earthquake released about 570 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 27,000× the energy of this one
2. Magna, Utah 2020 M 5.7 19,000× the energy of this one
3. Around the size people start to feel M 3.0 1.7× the energy of this one
4. This earthquake M 2.9 about 570 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 4.1 on 2017-10-10 — about 72 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. 6.5 Near Morgan Hill, California · 33 km SSW of this epicentre Jul 1, 1911
2. 6.2 Near San Jose, California · 28 km WSW of this epicentre Aug 3, 1903
3. 6.2 The 1984 Morgan Hill, California Earthquake · 17 km WSW of this epicentre Apr 24, 1984
4. 6.1 Near San Jose, California · 33 km SW of this epicentre Jun 11, 1903
5. 5.8 The 1979 Coyote Lake, California Earthquake · 32 km S of this epicentre Aug 6, 1979

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 37.3917, -121.5107. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.1 4km WNW of Mountain House, CA 21:02 UTC
2. 3.0 6km WNW of Mountain House, CA 20:58 UTC
3. 1.8 15km N of Hollister, CA 15:26 UTC
4. 1.8 6km SW of Gilroy, CA 22:33 UTC
5. 1.8 8km NE of Alum Rock, CA 02:43 UTC
6. 2.4 9km ENE of San Martin, CA 22:55 UTC
7. 2.3 13km NNE of Morgan Hill, CA 22:00 UTC
8. 1.8 10km ENE of Milpitas, CA 04:03 UTC
9. 1.6 8km NE of Alum Rock, CA 02:50 UTC
10. 1.7 10km E of Alum Rock, CA 20:35 UTC
11. 1.6 6km SSW of Gilroy, CA 18:07 UTC
12. 2.2 6km E of Fremont, CA 15:35 UTC
13. 1.8 5km NW of Mountain House, CA 01:46 UTC
14. 1.8 8km E of Interlaken, CA 20:43 UTC
15. 2.1 14km ENE of Seven Trees, CA 02:21 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 13:54 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.