QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mw

5km NW of Palomar Observatory, CA

· 13 km deep · released about 25 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Diego County 42 kmOrange County 87 kmRiverside County 93 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 4.2 (mw)
Depth
13 km below the surface
Felt
14549 reports · strongest reported intensity V
Measured shaking
intensity V (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
San Diego County, 42 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 531 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 14549 people have reported feeling it to USGS.

How big was it?

This earthquake released about 25 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 6,700× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 300× the energy of this one
  3. Magna, Utah 2020 M 5.7 210× the energy of this one
  4. This earthquake M 4.2 about 25 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 53× 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 33.3817, -116.9097. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Diego County, CA 42 km (26 mi) NNW of here earthquakes near San Diego County
Orange County, CA 87 km (54 mi) ESE of here earthquakes near Orange County
Riverside County, CA 93 km (58 mi) WSW of here earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.7 2km E of San Jacinto, CA
  2. 1.6 11km NNW of Julian, CA
  3. 1.6 9km NNW of Anza, CA
  4. 1.7 4km NW of Palomar Observatory, CA
  5. 1.7 21km NNW of Borrego Springs, CA
  6. 1.7 0km E of Julian, CA
  7. 1.6 22km SSW of La Quinta, CA
  8. 1.9 10km NNW of Anza, CA
  9. 1.6 14km SE of Anza, CA
  10. 1.5 13km SE of Anza, CA
  11. 1.6 13km SE of Anza, CA
  12. 1.7 11km NNE of Julian, CA
  13. 2.6 5km NW of Palomar Observatory, CA
  14. 3.4 5km NW of Palomar Observatory, CA
  15. 1.9 10km SSW of Idyllwild, 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 36 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.