QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4ml

5 km NNE of San Bernardino, CA

· 7.8 km deep · released about 1.8 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 73 kmLos Angeles County 92 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 3.4 (ml)
Depth
7.8 km below the surface
Felt
525 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Orange County, 73 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 193 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 525 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 92,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,900× the energy of this one
  4. This earthquake M 3.4 about 1.8 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.8× 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 34.1708, -117.2633. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 73 km (45 mi) NE of here earthquakes near Orange County
Los Angeles County, CA 92 km (57 mi) E of here earthquakes near Los Angeles County
San Bernardino County, CA 125 km (78 mi) SW of here earthquakes near San Bernardino County
Riverside County, CA 126 km (78 mi) WNW of here earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.7 4 km SE of Home Gardens, CA
  2. 2.0 1 km NE of Loma Linda, CA
  3. 1.6 6 km N of Beaumont, CA
  4. 1.5 4 km SE of Home Gardens, CA
  5. 1.7 7 km S of Big Bear City, CA
  6. 1.6 6 km NNE of Fontana, CA
  7. 1.8 3 km S of Loma Linda, CA
  8. 1.6 7 km SSE of Home Gardens, CA
  9. 2.5 3 km WSW of San Bernardino, CA
  10. 1.7 4 km ENE of Moreno Valley, CA
  11. 1.7 7 km N of Upland, CA
  12. 2.4 10 km ENE of Lake Arrowhead, CA
  13. 1.9 10 km ENE of Lake Arrowhead, CA
  14. 1.7 12 km SW of Big Bear Lake, CA
  15. 1.8 3 km NNE of Moreno Valley, 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 2018-05-08 — it released about 45 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.