Earthquake near Alamo, CA

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Alamo, 2 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: Danville, Diablo, Saranap, San Ramon, Walnut Creek, Acalanes Ridge.

How big was it?

This earthquake released about 5.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
3. Around the size people start to feel M 3.0 170× the energy of this one
4. This earthquake M 1.5 about 5.6 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 20,000 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

1. 7.9 The 1906 San Francisco, California Earthquake · 49 km WSW of this epicentre Apr 18, 1906
2. 6.0 The 2014 South Napa, California Earthquake · 49 km NNW of this epicentre Aug 24, 2014
3. 5.8 The 1980 Livermore, California Earthquake · 21 km E of this epicentre Jan 24, 1980
4. 5.7 15 km NE of East Foothills, California · 50 km SE of this epicentre Mar 31, 1986
5. 5.4 9 km NE of Livermore, California · 29 km ESE 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 37.8497, -122.0062. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.6 1km ESE of East Richmond Heights, CA 08:12 UTC
2. 2.5 3km ENE of Oakland, CA 19:07 UTC
3. 1.7 2km NNW of Crockett, CA 10:34 UTC
4. 2.4 1km NW of Crockett, CA 09:45 UTC
5. 1.7 6km NE of Blackhawk, CA 05:16 UTC
6. 1.6 2km NW of Crockett, CA 07:21 UTC
7. 2.7 2km NW of Crockett, CA 20:01 UTC
8. 3.5 2km NW of Crockett, CA 19:56 UTC
9. 2.0 4km E of El Sobrante, CA 11:18 UTC
10. 1.6 6km WNW of Mountain House, CA 22:57 UTC
11. 2.8 6km WNW of Mountain House, CA 01:58 UTC
12. 2.5 3km ESE of San Leandro, CA 19:28 UTC
13. 1.5 16km SSE of Livermore, CA 21:16 UTC
14. 1.7 2km E of Hayward, CA 06:24 UTC
15. 1.6 2km W of Diablo, CA 18:39 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 15:43 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.