Earthquake near San Antonio Heights, CA

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

At this magnitude and depth, people at rest would likely notice it out to about 15 km (9 mi) from the epicentre. In San Antonio Heights, 9 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.

Likely felt in: Rancho Cucamonga 9 km, intensity II · Upland 12 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 36 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 420,000× the energy of this one
2. Magna, Utah 2020 M 5.7 300,000× the energy of this one
3. Around the size people start to feel M 3.0 27× the energy of this one
4. This earthquake M 2.0 about 36 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 9 earthquakes of M5 or more within 50 km; the five largest:

1. 6.2 3 km SE of San Bernardino, California · 30 km ESE of this epicentre Jul 23, 1923
2. 5.9 The 1987 Whittier Narrows, California Earthquake · 49 km WSW of this epicentre Oct 1, 1987
3. 5.8 The 1991 Sierra Madre, California Earthquake · 40 km WNW of this epicentre Jun 28, 1991
4. 5.6 7km ENE of Running Springs, CA · 49 km E of this epicentre Oct 16, 1999
5. 5.5 The 1990 Upland, California Earthquake · 13 km WSW of this epicentre Feb 28, 1990

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 34.1840, -117.5670. 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. 2.1 4km E of Mountain View Acres, CA 11:59 UTC
2. 1.7 1km SW of Loma Linda, CA 17:49 UTC
3. 1.6 7km SSE of Home Gardens, CA 17:24 UTC
4. 2.7 7km S of Lytle Creek, CA 08:24 UTC
5. 1.5 6km SE of Loma Linda, CA 13:49 UTC
6. 2.0 5km NNW of Yorba Linda, CA 18:33 UTC
7. 2.3 1km SW of Mira Loma, CA 04:09 UTC
8. 1.8 1km ESE of Loma Linda, CA 16:51 UTC
9. 1.8 4km S of Charter Oak, CA 00:23 UTC
10. 1.6 5km NW of Highland, CA 11:10 UTC
11. 1.9 5km NW of Highland, CA 11:04 UTC
12. 2.4 6km NW of Highland, CA 07:40 UTC
13. 2.6 4km NNW of Fontana, CA 02:00 UTC
14. 2.0 0km SW of Colton, CA 12:52 UTC
15. 2.1 2km S of Placentia, CA 19:24 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 07:26 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.