14km ESE of Alum Rock, CA

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 342 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 100,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 4,600× the energy of this one
3. Magna, Utah 2020 M 5.7 3,200× the energy of this one
4. This earthquake M 3.4 about 1.7 tons of TNT
5. Around the size people start to feel M 3.0 this one released 3.5× more

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.

Where

Epicentre 37.3122, -121.6782. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.3 15km E of Seven Trees, CA 04:29 UTC
2. 2.1 16km E of Seven Trees, CA 09:00 UTC
3. 1.5 15km E of Seven Trees, CA 08:18 UTC
4. 2.7 14km ESE of Alum Rock, CA 00:20 UTC
5. 1.6 15km E of Seven Trees, CA 23:35 UTC
6. 2.0 15km E of Seven Trees, CA 23:07 UTC
7. 3.5 15km E of Seven Trees, CA 22:08 UTC
8. 2.4 16km E of Seven Trees, CA 21:49 UTC
9. 1.5 15km E of Seven Trees, CA 19:41 UTC
10. 2.2 11km ESE of Alum Rock, CA 19:02 UTC
11. 2.9 15km E of Seven Trees, CA 18:47 UTC
12. 5.1 15km ESE of Alum Rock, CA 18:42 UTC
13. 2.3 10km NW of Westley, CA 13:24 UTC
14. 1.6 9km ENE of San Martin, CA 16:22 UTC
15. 2.6 9km ENE of San Martin, CA 15:14 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 10:47 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 4.2 on 2021-01-17 — it released about 18 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

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.