QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

21km ESE of Anza, CA

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

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Riverside County 52 kmSan Diego County 57 kmImperial County 114 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
7.6 km below the surface
Felt
24 reports · strongest reported intensity III
Nearest
Riverside County, 52 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3162 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 24 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 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× 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 1.4× 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 33.4638, -116.4702. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Riverside County, CA 52 km (33 mi) SW of here earthquakes near Riverside County
San Diego County, CA 57 km (35 mi) NNE of here earthquakes near San Diego County
Imperial County, CA 114 km (71 mi) WNW of here earthquakes near Imperial County

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

Aftershocks so far

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

  1. 1.9 14km SW of Borrego Springs, CA
  2. 4.0 14km NE of Julian, CA
  3. 2.2 14km NE of Julian, CA
  4. 2.6 14km NE of Julian, CA
  5. 1.6 14km N of Ocotillo Wells, CA
  6. 2.1 8km NE of Aguanga, CA
  7. 1.6 8km S of Idyllwild, CA
  8. 1.9 9km NNW of Anza, CA
  9. 1.7 22km ESE of Anza, CA
  10. 1.9 8km E of Borrego Springs, CA
  11. 1.9 22km ESE of Anza, CA
  12. 1.7 16km N of Ocotillo Wells, CA
  13. 1.6 8km ENE of Aguanga, CA
  14. 2.0 8km NE of Aguanga, CA
  15. 2.5 11km E of Borrego Springs, 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 5.2 on 2016-06-10 — it released about 1,400 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.