QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

3km SSW of Palomar Observatory, CA

· 11 km deep · released about 38 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Diego County 35 kmOrange County 92 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 2.1 (ml)
Depth
11 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
San Diego County, 35 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2432 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 lb of TNT

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 33.3277, -116.8758. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Diego County, CA 35 km (22 mi) NNW of here earthquakes near San Diego County
Orange County, CA 92 km (57 mi) ESE of here earthquakes near Orange County
Riverside County, CA 93 km (57 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

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

  1. 1.7 6km SW of Idyllwild, CA
  2. 1.5 18km ESE of Anza, CA
  3. 1.8 13km W of Anza, CA
  4. 1.7 8km SSW of Idyllwild, CA
  5. 2.0 15km SE of Anza, CA
  6. 2.1 5km N of Murrieta, CA
  7. 1.8 13km NNW of Borrego Springs, CA
  8. 2.1 4km E of Julian, CA
  9. 1.9 6km NNW of Lakeside, CA
  10. 2.9 6km NNW of Lakeside, CA
  11. 1.7 8km NNW of Borrego Springs, CA
  12. 2.1 19km ESE of Anza, CA
  13. 1.6 19km ESE of Anza, CA
  14. 1.6 20km ESE of Anza, CA
  15. 1.6 21km ESE of Anza, 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 48,000 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.