QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mw

16km NNE of Borrego Springs, CA

· 14 km deep · released about 12 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Riverside County 48 kmSan Diego County 60 kmImperial County 95 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 3.9 (mw)
Depth
14 km below the surface
Felt
101 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
Riverside County, 48 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1564 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 101 people have reported feeling it to USGS.

How big was it?

This earthquake released about 12 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 14,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 620× the energy of this one
  3. Magna, Utah 2020 M 5.7 440× the energy of this one
  4. This earthquake M 3.9 about 12 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 26× 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 33.3797, -116.2983. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Riverside County, CA 48 km (30 mi) SW of here earthquakes near Riverside County
San Diego County, CA 60 km (37 mi) NE of here earthquakes near San Diego County
Imperial County, CA 95 km (59 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

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

  1. 1.8 9km NE of Aguanga, CA
  2. 1.7 8km NE of Aguanga, CA
  3. 1.7 23km ESE of Anza, CA
  4. 1.6 23km ESE of Anza, CA
  5. 1.8 8km NE of Aguanga, CA
  6. 1.8 22km E of Julian, CA
  7. 2.0 9km NE of Aguanga, CA
  8. 1.5 7km E of Palomar Observatory, CA
  9. 2.8 10km ESE of Anza, CA
  10. 1.5 1km SW of Lake Henshaw, CA
  11. 2.0 9km NE of Aguanga, CA
  12. 2.5 5km E of Ocotillo Wells, CA
  13. 1.5 8km WSW of Anza, CA
  14. 1.7 8km NE of Aguanga, CA
  15. 2.4 8km NE of Aguanga, 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 75 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.