Earthquake · reviewed by a seismologist
M 2.4ml
Earthquake near Julian, CA
No earthquake was likely felt in Julian in the 24 hours to 6:05 am PST (14:05 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 19 km (12 mi) east-southeast of Julian, CA, at 1:06 am PDT on 23 September 2020 (08:06 UTC), 5.4 km deep. 4 people have reported feeling it to USGS.
USGS: 19km ESE of Julian, CA
73 km (46 mi) ENE of San Diego, CA · 59 km (36 mi) ENE of Santee, CA
- When
- 1:06 am PDT on 23 September 2020 ()
- Where
- 19 km (12 mi) east-southeast of Julian, CA · earthquakes near Julian
- Magnitude
- M 2.4 (ml)
- Depth
- 5.4 km below the surface
- Felt
- 4 reports · strongest reported intensity II
- Nearest
- San Diego County, 35 km W
- Nearest mapped fault
- Elsinore fault, under 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 2240 days ago
Earthquake alerts for Julian, CA
Get a notification in this browser when USGS records an earthquake near Julian, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 20 km (12 mi) from the epicentre. In Julian, 19 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.
Likely felt in: Julian 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 120 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.
- Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
- Magna, Utah 2020 M 5.7 89,000× the energy of this one
- Around the size people start to feel M 3.0 7.9× the energy of this one
- This earthquake M 2.4 about 120 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 15,000 times the energy of this one.
Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:
- 6.6 The 1968 Borrego Mountain, California Earthquake · 31 km ENE of this epicentre
- 6.4 The 1954 San Jacinto Fault, California Earthquake · 41 km NE of this epicentre
- 6.0 16km WSW of Oasis, CA · 42 km NNE of this epicentre
- 5.7 Eastern San Diego County, California · 33 km ENE of this epicentre
- 5.5 8km NNE of Ocotillo Wells, CA · 33 km ENE 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 33.0437, -116.3983. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Diego County, CA | 35 km (22 mi) | W | earthquakes near San Diego County |
| Riverside County, CA | 85 km (53 mi) | NNE | earthquakes near Riverside County |
| Imperial County, CA | 97 km (60 mi) | E | earthquakes near Imperial County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
52 earthquakes have been recorded within 50 km since this one.
- 1.6 24km SSW of La Quinta, CA
- 2.5 18km N of Borrego Springs, CA
- 1.6 13km NNW of Borrego Springs, CA
- 1.8 5km SSE of Lake Henshaw, CA
- 1.9 17km SE of Ocotillo Wells, CA
- 1.5 24km ESE of Anza, CA
- 1.6 11km ENE of Ocotillo Wells, CA
- 1.6 14km E of Borrego Springs, CA
- 1.7 17km SSW of Oasis, CA
- 2.3 19km SE of Ocotillo Wells, CA
- 2.6 26km N of Ocotillo, CA
- 1.5 20km ESE of Anza, CA
- 2.3 17km ESE of Julian, CA
- 2.3 26km SSW of Ocotillo Wells, CA
- 2.0 12km E of Ocotillo Wells, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.