QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

1km WNW of Pomona, CA

· 2.8 km deep · released about 49 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 44 kmLos Angeles County 48 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
2.8 km below the surface
Felt
107 reports · strongest reported intensity IV
Nearest
Orange County, 44 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2984 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 107 people have reported feeling it to USGS.

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 34.0672, -117.7692. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 44 km (27 mi) N of here earthquakes near Orange County
Los Angeles County, CA 48 km (30 mi) ESE of here earthquakes near Los Angeles County
San Diego County, CA 148 km (92 mi) NW 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

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

  1. 2.5 2km NE of Villa Park, CA
  2. 1.9 4km SE of Home Gardens, CA
  3. 1.7 1km ENE of Yorba Linda, CA
  4. 1.5 4km SSE of Home Gardens, CA
  5. 2.3 3km SSE of Charter Oak, CA
  6. 1.5 2km SE of Home Gardens, CA
  7. 2.8 3km NW of Fontana, CA
  8. 2.6 13km NE of Trabuco Canyon, CA
  9. 2.0 1km ESE of Loma Linda, CA
  10. 2.4 3km NNE of Rancho Cucamonga, CA
  11. 1.6 1km SSE of Placentia, CA
  12. 2.6 3km SSW of Signal Hill, CA
  13. 1.9 2km WSW of Yorba Linda, CA
  14. 1.7 6km ESE of Ontario, CA
  15. 2.7 6km ESE of Ontario, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.