QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

Earthquake near Julian, CA

No earthquake was likely felt in Julian in the 24 hours to 10:20 pm PST (06:20 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 2.8 earthquake was recorded 11 km (7 mi) northeast of Julian, CA, at 9:36 pm PDT on 18 April 2017 (04:36 UTC), 7.5 km deep. 25 people have reported feeling it to USGS.

USGS: 11km NE of Julian, CA

68 km (42 mi) ENE of San Diego, CA · 51 km (32 mi) E of Escondido, CA

9:36 pm PDT, Apr 18, 2017 · · 7.5 km deep · released about 430 lb of TNT

10 km30 km60 km120 km N San Diego County 27 kmRiverside County 81 kmImperial County 110 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
9:36 pm PDT on 18 April 2017 ()
Where
11 km (7 mi) northeast of Julian, CA · earthquakes near Julian
Magnitude
M 2.8 (ml)
Depth
7.5 km below the surface
Felt
25 reports · strongest reported intensity IV
Nearest
San Diego County, 27 km WSW
Nearest mapped fault
Elsinore fault, 1 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 3467 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 25 km (16 mi) from the epicentre. In Julian, 11 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 11 km, intensity III · Borrego Springs 18 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 430 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 35,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 25,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.2× the energy of this one
  4. This earthquake M 2.8 about 430 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 4,300 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 The 1968 Borrego Mountain, California Earthquake · 40 km E of this epicentre
  2. 6.4 The 1954 San Jacinto Fault, California Earthquake · 45 km ENE of this epicentre
  3. 6.0 16km WSW of Oasis, CA · 38 km NE of this epicentre
  4. 5.7 Eastern San Diego County, California · 40 km E of this epicentre
  5. 5.5 8km NNE of Ocotillo Wells, CA · 40 km E 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 33.1497, -116.5265. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Diego County, CA 27 km (17 mi) WSW earthquakes near San Diego County
Riverside County, CA 81 km (50 mi) NE earthquakes near Riverside County
Imperial County, CA 110 km (68 mi) E earthquakes near Imperial County
Orange County, CA 130 km (81 mi) WNW 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 8km NE of Aguanga, CA
  2. 1.6 8km NE of Aguanga, CA
  3. 2.0 8km NE of Aguanga, CA
  4. 2.0 8km NE of Aguanga, CA
  5. 1.8 12km NNE of Ocotillo Wells, CA
  6. 2.2 7km NNE of Borrego Springs, CA
  7. 2.4 14km W of Salton City, CA
  8. 2.1 14km W of Salton City, CA
  9. 2.3 10km SW of Salton City, CA
  10. 2.1 8km ENE of Borrego Springs, CA
  11. 2.4 7km SE of Julian, CA
  12. 1.6 11km SW of Anza, CA
  13. 1.7 6km NNE of Borrego Springs, CA
  14. 1.8 18km N of Borrego Springs, CA
  15. 1.6 6km NE 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.

On USGS

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