QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4ml

Earthquake near Julian, CA

No earthquake was likely felt in Julian in the 24 hours to 10:54 pm PST (06:54 UTC). The last one was M 4.9, 151 km (94 mi) ESE, at 10:27 am PST on 3 November 2026, estimated intensity II (weak) in town; 321 felt reports to USGS. Every earthquake near Julian

This page: a magnitude 2.4 earthquake was recorded 8 km (5 mi) north-northwest of Julian, CA, at 7:50 am PST on 16 December 2016 (15:50 UTC), 2.5 km deep.

USGS: 8km NNW of Julian, CA

58 km (36 mi) NE of San Diego, CA · 40 km (25 mi) E of Escondido, CA

7:50 am PST, Dec 16, 2016 · · 2.5 km deep · released about 110 lb of TNT

10 km30 km60 km120 km N San Diego County 17 kmRiverside County 89 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
7:50 am PST on 16 December 2016 ()
Where
8 km (5 mi) north-northwest of Julian, CA · earthquakes near Julian
Magnitude
M 2.4 (ml)
Depth
2.5 km below the surface
Felt
no reports yet
Nearest
San Diego County, 17 km SW
Nearest mapped fault
Elsinore fault, 5 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 3563 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 21 km (13 mi) from the epicentre. In Julian, 8 km away, the estimate is intensity III (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.

Likely felt in: Julian 8 km, intensity III · San Diego Country Estates 19 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 110 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 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 95,000× the energy of this one
  3. Around the size people start to feel M 3.0 8.5× the energy of this one
  4. This earthquake M 2.4 about 110 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

The largest earthquake within 50 km since 2016 was M 5.2 on 2016-06-10 — about 16,000 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 16km WSW of Oasis, CA · 47 km NE of this epicentre
  2. 5.5 1km ENE of Borrego Springs, CA · 30 km ENE of this epicentre
  3. 5.4 20km NNW of Borrego Springs, CA · 35 km NNE of this epicentre
  4. 5.3 18km ESE of Anza, CA · 40 km NNE of this epicentre
  5. 5.2 10km ESE of Anza, CA · 45 km N 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 33.1353, -116.6472. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Diego County, CA 17 km (11 mi) SW earthquakes near San Diego County
Riverside County, CA 89 km (55 mi) NE earthquakes near Riverside County
Orange County, CA 121 km (75 mi) WNW 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. 1.9 8km NE of Aguanga, CA
  2. 1.7 8km NE of Aguanga, CA
  3. 1.7 11km S of Borrego Springs, CA
  4. 1.6 8km NNE of Borrego Springs, CA
  5. 1.7 12km N of Borrego Springs, CA
  6. 1.8 7km NNE of Borrego Springs, CA
  7. 2.0 26km ENE of Pine Valley, CA
  8. 2.0 17km SE of Julian, CA
  9. 2.0 27km ENE of Pine Valley, CA
  10. 1.7 9km NE of Aguanga, CA
  11. 2.0 26km NW of Ocotillo, CA
  12. 1.5 16km NNW of Borrego Springs, CA
  13. 1.6 4km WSW of Borrego Springs, CA
  14. 1.8 6km ENE of Borrego Springs, CA
  15. 1.7 12km NNE of Julian, 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.