QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

11km N of Westmorland, CA

· 7.6 km deep · released about 1,600 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Imperial County 29 kmRiverside County 74 kmSan Diego County 106 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
1 report · strongest reported intensity II
Nearest
Imperial County, 29 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1858 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 1,600 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 210,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 9,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,700× the energy of this one
  4. This earthquake M 3.1 about 1,600 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.7× 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 33.1387, -115.6413. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Imperial County, CA 29 km (18 mi) WNW of here earthquakes near Imperial County
Riverside County, CA 74 km (46 mi) SSE of here earthquakes near Riverside County
San Diego County, CA 106 km (66 mi) E 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

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

  1. 2.2 8km WNW of Holtville, CA
  2. 1.9 9km WNW of Holtville, CA
  3. 1.6 16km E of Ocotillo, CA
  4. 1.5 14km WNW of Calipatria, CA
  5. 2.1 12km WNW of Calipatria, CA
  6. 1.6 15km E of Ocotillo Wells, CA
  7. 1.6 11km WSW of Niland, CA
  8. 2.0 5km S of Brawley, CA
  9. 1.9 10km W of Calipatria, CA
  10. 1.9 17km E of Ocotillo, CA
  11. 1.9 10km WNW of Calipatria, CA
  12. 2.0 11km W of Calipatria, CA
  13. 2.8 8km WNW of Calipatria, CA
  14. 1.6 16km NNW of Westmorland, CA
  15. 2.1 15km E of Ocotillo Wells, 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 5.3 on 2021-06-05 — 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.