Earthquake near Castro Valley, 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 23 km (14 mi) from the epicentre. In Castro Valley, 3 km away, the estimate is intensity III (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: Castro Valley 3 km, intensity III · San Leandro 4 km, intensity III · San Lorenzo 5 km, intensity III · Hayward 5 km, intensity III · San Ramon 14 km, intensity II · Alameda 15 km, intensity II · Union City 15 km, intensity II · Dublin 15 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 280 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 55,000× the energy of this one
2. Magna, Utah 2020 M 5.7 39,000× the energy of this one
3. Around the size people start to feel M 3.0 3.5× the energy of this one
4. This earthquake M 2.6 about 280 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 4.5 on 2019-10-15 — about 540 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

1. 7.9 The 1906 San Francisco, California Earthquake · 39 km W of this epicentre Apr 18, 1906
2. 5.8 The 1980 Livermore, California Earthquake · 33 km ENE of this epicentre Jan 24, 1980
3. 5.7 15 km NE of East Foothills, California · 45 km SE of this epicentre Mar 31, 1986
4. 5.5 6 km NNE of East Foothills, California · 43 km SE of this epicentre Oct 31, 2007
5. 5.4 9 km NE of Livermore, California · 36 km E of this epicentre Jan 27, 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 37.7113, -122.1112. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.8 1km S of San Ramon, CA 08:17 UTC
2. 1.7 1km E of Fremont, CA 10:50 UTC
3. 1.7 4km NNW of Pittsburg, CA 13:36 UTC
4. 2.4 3km NW of Pittsburg, CA 10:02 UTC
5. 1.6 4km ENE of Walnut Creek, CA 09:34 UTC
6. 2.1 10km SE of Livermore, CA 22:21 UTC
7. 1.6 1km N of San Pablo, CA 21:13 UTC
8. 2.0 12km SW of Byron, CA 17:12 UTC
9. 1.7 1km NE of Diablo, CA 02:33 UTC
10. 2.1 1km NE of Diablo, CA 02:09 UTC
11. 1.8 0km E of Diablo, CA 00:26 UTC
12. 1.5 0km E of Diablo, CA 16:43 UTC
13. 1.7 2km ESE of Woodside, CA 13:55 UTC
14. 1.5 2km WNW of Concord, CA 07:01 UTC
15. 1.7 3km ENE of San Ramon, CA 20:21 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 13:09 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.