Earthquake near East Foothills, 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 22 km (14 mi) from the epicentre. In East Foothills, 5 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: Milpitas 8 km, intensity III · San Jose 12 km, intensity II · Santa Clara 14 km, intensity II · Campbell 19 km, intensity II · Sunnyvale 20 km, intensity II · Fremont 21 km, intensity II · Cupertino 22 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
3. Around the size people start to feel M 3.0 5.6× the energy of this one
4. This earthquake M 2.5 about 170 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 20 earthquakes of M5 or more within 50 km; the five largest:

1. 6.9 The 1989 Loma Prieta, California Earthquake · 43 km S of this epicentre Oct 18, 1989
2. 6.5 Near Morgan Hill, California · 38 km SSE of this epicentre Jul 1, 1911
3. 6.2 Near San Jose, California · 14 km S of this epicentre Aug 3, 1903
4. 6.2 The 1984 Morgan Hill, California Earthquake · 17 km SE of this epicentre Apr 24, 1984
5. 6.1 Near San Jose, California · 25 km S of this epicentre Jun 11, 1903

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 37.4217, -121.8160. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.9 4km NE of Portola Valley, CA 15:30 UTC
2. 1.7 5km NNE of San Leandro, CA 17:08 UTC
3. 1.6 3 km W of Portola Valley, California 02:55 UTC
4. 1.8 4 km WNW of La Honda, California 16:28 UTC
5. 1.5 11 km ESE of East Foothills, California 05:05 UTC
6. 1.7 1 km N of North Fair Oaks, California 19:36 UTC
7. 1.9 14 km E of Seven Trees, California 13:52 UTC
8. 2.0 10 km ENE of Milpitas, California 16:47 UTC
9. 2.2 8 km ENE of San Martin, California 14:53 UTC
10. 1.6 12 km ESE of East Foothills, California 21:52 UTC
11. 2.7 8 km ENE of San Martin, California 08:09 UTC
12. 1.6 6 km NNW of Day Valley, California 04:08 UTC
13. 2.3 2 km SSE of Dublin, California 21:15 UTC
14. 2.6 15 km SSE of Livermore, California 09:43 UTC
15. 1.6 0 km S of Los Altos Hills, California 04:50 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 07:28 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.