QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

2km NNW of Palomar Observatory, CA

· 5.3 km deep · released about 49 lb of TNT

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10 km30 km60 km120 km N San Diego County 40 kmRiverside County 90 kmOrange County 90 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
5.3 km below the surface
Felt
no reports yet
Nearest
San Diego County, 40 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1721 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 49 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 5.8 310,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 220,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 49 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 33.3713, -116.8740. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Diego County, CA 40 km (25 mi) NNW of here earthquakes near San Diego County
Riverside County, CA 90 km (56 mi) WSW of here earthquakes near Riverside County
Orange County, CA 90 km (56 mi) ESE of here earthquakes near Orange County

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

Aftershocks so far

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

  1. 2.3 23km ESE of Anza, CA
  2. 1.5 23km SSW of La Quinta, CA
  3. 2.2 6km SSW of Warner Springs, CA
  4. 2.0 23km ESE of Anza, CA
  5. 1.8 24km ESE of Anza, CA
  6. 1.5 19km SE of Anza, CA
  7. 4.0 5km WSW of Palomar Observatory, CA
  8. 1.6 11km N of Borrego Springs, CA
  9. 1.5 5km WNW of Lake Henshaw, CA
  10. 3.2 20km N of Borrego Springs, CA
  11. 1.6 3km NNW of Palomar Observatory, CA
  12. 1.8 17km SE of Anza, CA
  13. 2.1 6km NNE of Anza, CA
  14. 1.9 13km WNW of Anza, CA
  15. 2.2 23km 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 38,000 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.