Earthquake near San Jacinto, 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 30 km (19 mi) from the epicentre. In San Jacinto, 10 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: San Jacinto 10 km, intensity III · Banning 10 km, intensity III · Valle Vista 10 km, intensity III · Hemet 14 km, intensity II · Beaumont 14 km, intensity II · Idyllwild 18 km, intensity II · Yucaipa 27 km, intensity II · Menifee 28 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
3. Around the size people start to feel M 3.0 1.4× the energy of this one
4. This earthquake M 2.9 about 680 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 2018-05-08 — about 240 times the energy of this one.

Before 2016, the USGS record lists 22 earthquakes of M5 or more within 50 km; the five largest:

1. 6.7 The 1918 San Jacinto, California Earthquake · 12 km SW of this epicentre Apr 21, 1918
2. 6.3 The 1992 Big Bear, California Earthquake · 41 km N of this epicentre Jun 28, 1992
3. 6.2 3 km SE of San Bernardino, California · 45 km NW of this epicentre Jul 23, 1923
4. 6.0 The 1986 North Palm Springs, California Earthquake · 30 km NE of this epicentre Jul 8, 1986
5. 5.6 7km ENE of Running Springs, CA · 47 km NNW of this epicentre Oct 16, 1999

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 33.8362, -116.8723. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 1.6 5 km WSW of Morongo Valley, CA 15:40 UTC
2. 1.6 6 km WSW of Anza, CA 05:00 UTC
3. 3.1 5 km N of Cabazon, CA 18:29 UTC
4. 3.0 5 km N of Cabazon, CA 18:28 UTC
5. 2.9 3 km W of Banning, CA 01:02 UTC
6. 2.9 3 km W of Banning, CA 19:18 UTC
7. 1.6 7 km N of Anza, CA 08:14 UTC
8. 1.9 6 km S of Redlands, CA 05:43 UTC
9. 1.7 10 km SW of Idyllwild, CA 20:32 UTC
10. 1.6 1 km SSE of Hemet, CA 13:38 UTC
11. 1.7 10 km WNW of Morongo Valley, CA 00:09 UTC
12. 1.6 8 km N of Anza, CA 22:18 UTC
13. 2.4 6 km SW of Idyllwild, CA 06:37 UTC
14. 1.6 6 km WSW of Anza, CA 20:08 UTC
15. 2.3 2 km SE of Loma Linda, CA 18:25 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 01:31 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.