Earthquake near Long Beach, 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 13 km (8 mi) from the epicentre. In Long Beach, 3 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: Long Beach 3 km, intensity II · Signal Hill 5 km, intensity II · Seal Beach 5 km, intensity II · Lakewood 10 km, intensity II · Cypress 12 km, intensity II · Cerritos 13 km, intensity II · Bellflower 14 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 40 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 380,000× the energy of this one
2. Magna, Utah 2020 M 5.7 270,000× the energy of this one
3. Around the size people start to feel M 3.0 24× the energy of this one
4. This earthquake M 2.1 about 40 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 2020-09-19 — about 4,900 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

1. 6.4 The 1933 Long Beach, California Earthquake · 21 km SE of this epicentre Mar 11, 1933
2. 5.9 The 1987 Whittier Narrows, California Earthquake · 34 km NNE of this epicentre Oct 1, 1987
3. 5.4 5km S of Chino Hills, CA · 41 km ENE of this epicentre Jul 29, 2008
4. 5.3 2 km SSW of Santa Monica, California · 41 km NW of this epicentre Aug 4, 1927
5. 5.3 7km W of Newport Beach, CA · 21 km SE of this epicentre Mar 11, 1933

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 33.7640, -118.1550. 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. 1.7 7 km SSW of Seal Beach, CA 03:24 UTC
2. 1.8 4 km NE of View Park-Windsor Hills, CA 16:10 UTC
3. 1.5 0 km NNE of Carson, CA 12:59 UTC
4. 2.8 4 km SSE of Highland Park, CA 22:59 UTC
5. 1.7 3 km SSE of Highland Park, CA 15:52 UTC
6. 1.5 4 km SSE of Highland Park, CA 02:51 UTC
7. 1.5 6 km ENE of Villa Park, CA 11:32 UTC
8. 1.6 2 km N of Orange, CA 19:02 UTC
9. 1.8 5 km E of Inglewood, CA 13:13 UTC
10. 1.6 2 km WNW of Villa Park, CA 01:42 UTC
11. 1.6 5 km SSW of South Pasadena, CA 23:12 UTC
12. 1.8 1 km ENE of Valinda, CA 07:14 UTC
13. 2.4 16 km SSW of San Pedro, CA 02:12 UTC
14. 1.8 16 km S of Rancho Palos Verdes, CA 11:53 UTC
15. 1.6 2 km NNW of Orange, CA 06:39 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 13:02 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.