QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4ml

44km WSW of Rosarito, B.C., MX

Yes. A magnitude 2.4 earthquake was recorded 44km WSW of Rosarito, B.C., MX, 78 km (49 mi) SSW of San Diego, CA, at 11:47 pm PDT on 21 April 2021 (06:47 UTC), 18 km deep.

78 km (49 mi) SSW of San Diego, CA

· 18 km deep · released about 140 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Diego County 115 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 2.4 (ml)
Depth
18 km below the surface
Felt
no reports yet
Nearest
San Diego County, 115 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2030 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 140 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 110,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 78,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.9× the energy of this one
  4. This earthquake M 2.4 about 140 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 32.1637, -117.4540. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Diego County, CA 115 km (71 mi) NNE earthquakes near San Diego County

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

Aftershocks so far

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

  1. 2.2 57km WSW of Rosarito, B.C., MX
  2. 2.0 40km SW of Primo Tapia, B.C., MX
  3. 2.4 45km WSW of Coronado, CA
  4. 1.6 7km SW of Primo Tapia, B.C., MX
  5. 1.6 7km SW of Primo Tapia, B.C., MX
  6. 2.5 8km SSW of Primo Tapia, B.C., MX
  7. 1.6 8km SW of San Ysidro, CA
  8. 2.4 19km WSW of Primo Tapia, B.C., MX
  9. 3.6 46km SW of Primo Tapia, B.C., MX
  10. 2.5 24km WSW of Rosarito, B.C., MX
  11. 1.9 23km SW of Rosarito, B.C., MX
  12. 1.7 24km W of Rosarito, B.C., MX
  13. 2.6 41km W of El Sauzal, B.C., MX
  14. 3.0 45km SW of Primo Tapia, B.C., MX
  15. 2.0 13km NW of Rosarito, B.C., MX

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.