QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

5km ESE of Yorba Linda, CA

· 4.3 km deep · released about 1,300 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 22 kmLos Angeles County 58 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 3.1 (ml)
Depth
4.3 km below the surface
Felt
744 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Orange County, 22 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 879 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 744 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 270,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,500× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.3× more

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.

Where

Epicentre 33.8697, -117.7647. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 22 km (13 mi) N of here earthquakes near Orange County
Los Angeles County, CA 58 km (36 mi) SE of here earthquakes near Los Angeles County
San Diego County, CA 131 km (82 mi) NW of here earthquakes near San Diego County

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

Aftershocks so far

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

  1. 2.0 6km N of Fontana, CA
  2. 1.9 10km WSW of Corona, CA
  3. 1.5 4km NNW of Diamond Bar, CA
  4. 1.7 7km SSE of Home Gardens, CA
  5. 1.6 3km NNW of Fontana, CA
  6. 1.9 10km WSW of Corona, CA
  7. 1.6 2km SSE of Dana Point, CA
  8. 1.8 4km SE of Home Gardens, CA
  9. 2.1 3km N of Colton, CA
  10. 2.6 2km S of Placentia, CA
  11. 1.6 7km SSE of Home Gardens, CA
  12. 1.6 7km SSW of Devore, CA
  13. 1.6 4km SE of Home Gardens, CA
  14. 1.7 5km NW of Mira Loma, CA
  15. 1.5 5km SSE of Home Gardens, CA

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

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2020-09-19 — it released about 150 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.