Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near San Diego, CA
No earthquake was likely felt in San Diego in the 24 hours to 4:22 am PST (12:22 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 1.8 earthquake was recorded 48 km (30 mi) west-northwest of San Diego, CA, at 6:28 am PDT on 20 September 2020 (13:28 UTC), 15 km deep.
USGS: 32km WSW of Encinitas, CA
46 km (29 mi) WNW of San Diego, CA · 35 km (22 mi) WSW of Encinitas, CA
- When
- 6:28 am PDT on 20 September 2020 ()
- Where
- 48 km (30 mi) west-northwest of San Diego, CA · earthquakes near San Diego
- Magnitude
- M 1.8 (ml)
- Depth
- 15 km below the surface
- Felt
- no reports yet
- Nearest
- San Diego County, 79 km E
- Nearest mapped fault
- Carlsbad fault, 12 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 2241 days ago
Earthquake alerts for San Diego, CA
Get a notification in this browser when USGS records an earthquake near San Diego, 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 it was probably too small to be felt, even directly above it. In San Diego, 48 km away, the estimate is intensity I (not felt). 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 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
- Magna, Utah 2020 M 5.7 810,000× the energy of this one
- Around the size people start to feel M 3.0 72× the energy of this one
- This earthquake M 1.8 about 13 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:
- 5.5 The 1986 Oceanside, California Earthquake · 25 km W 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 32.9377, -117.6115. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Diego County, CA | 79 km (49 mi) | E | earthquakes near San Diego County |
| Orange County, CA | 83 km (52 mi) | N | earthquakes near Orange County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
48 earthquakes have been recorded within 50 km since this one.
- 1.6 9km SSE of San Clemente, CA
- 2.3 42km WSW of Encinitas, CA
- 2.5 44km SE of Avalon, CA
- 1.6 25km WSW of Encinitas, CA
- 2.1 29km WSW of Carlsbad, CA
- 1.7 17km W of La Jolla, CA
- 2.0 49km ENE of San Clemente Is. (SE tip), CA
- 1.9 47km SSW of San Clemente, CA
- 1.6 49km ENE of San Clemente Is. (SE tip), CA
- 2.3 36km NE of San Clemente Is. (SE tip), CA
- 2.3 45km NE of San Clemente Is. (SE tip), CA
- 1.7 4km WNW of Camp Pendleton South, CA
- 2.1 39km W of La Jolla, CA
- 1.8 16km WSW of La Jolla, CA
- 1.7 38km WSW of Carlsbad, 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.