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 32 km (20 mi) from the epicentre. In San Jacinto, 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: San Jacinto 3 km, intensity III · Hemet 7 km, intensity III · East Hemet 8 km, intensity III · Valle Vista 9 km, intensity III · Beaumont 13 km, intensity II · Banning 15 km, intensity II · Menifee 19 km, intensity II · Cabazon 20 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 810 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 420,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
3. Magna, Utah 2020 M 5.7 13,000× the energy of this one
4. This earthquake M 3.0 about 810 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 200 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

1. 6.7 The 1918 San Jacinto, California Earthquake · 5 km S of this epicentre Apr 21, 1918
2. 6.3 The 1992 Big Bear, California Earthquake · 46 km NNE of this epicentre Jun 28, 1992
3. 6.2 3 km SE of San Bernardino, California · 41 km NW of this epicentre Jul 23, 1923
4. 6.0 The 1910 Lake Elsinore, California Earthquake · 42 km WSW of this epicentre May 15, 1910
5. 6.0 The 1986 North Palm Springs, California Earthquake · 39 km ENE of this epicentre Jul 8, 1986

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 33.8088, -116.9645. Map © OpenStreetMap contributors.

Nearby places

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

Aftershocks so far

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

1. 2.3 3 km N of San Jacinto, CA 03:52 UTC
2. 0.8 3 km N of San Jacinto, CA 03:42 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 05:01 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

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.