QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near San Diego, CA

No earthquake was likely felt in San Diego in the 24 hours to 12:51 pm PST (20:51 UTC). The last one was M 4.7, 152 km (95 mi) E, at 12:10 am PDT on 10 May 2026, estimated intensity II (weak) in town; 203 felt reports to USGS. Every earthquake near San Diego

This page: a magnitude 1.7 earthquake was recorded 27 km (17 mi) west-northwest of San Diego, CA, at 5:55 pm PST on 29 December 2021 (01:55 UTC), 13 km deep.

USGS: 18km WSW of La Jolla, CA

29 km (18 mi) W of San Diego, CA

5:55 pm PST, Dec 29, 2021 · · 13 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N San Diego County 68 kmOrange County 105 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
5:55 pm PST on 29 December 2021 ()
Where
27 km (17 mi) west-northwest of San Diego, CA · earthquakes near San Diego
Magnitude
M 1.7 (ml)
Depth
13 km below the surface
Felt
no reports yet
Nearest
San Diego County, 68 km ENE
Nearest mapped fault
Carlsbad fault, 16 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1758 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In San Diego, 27 km away, the estimate is intensity II (weak). 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.

Earthquakes near other towns within 30 km: Del Mar, Coronado, Solana Beach.

How big was it?

This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.5 The 1986 Oceanside, California Earthquake · 46 km WNW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 32.7767, -117.4413. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Diego County, CA 68 km (42 mi) ENE earthquakes near San Diego County
Orange County, CA 105 km (65 mi) NNW earthquakes near Orange County

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

Aftershocks so far

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

  1. 1.5 1km ESE of San Ysidro, CA
  2. 1.6 45 km WSW of Coronado, CA
  3. 1.8 23 km WSW of Encinitas, CA
  4. 1.8 3km NE of Rancho San Diego, CA
  5. 1.5 9km SSW of Escondido, CA
  6. 2.4 45km WSW of Coronado, CA
  7. 1.6 6km E of Chula Vista, CA
  8. 1.6 24km WSW of Carlsbad, CA
  9. 1.7 44km WSW of Carlsbad, CA
  10. 1.6 26km WSW of Carlsbad, CA
  11. 1.7 10km SW of La Jolla, CA
  12. 1.6 4km NE of San Ysidro, CA
  13. 2.4 15km SW of La Jolla, CA
  14. 1.5 6km NW of Lakeside, CA
  15. 1.5 3km ENE of San Ysidro, 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.