QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mw

Earthquake near Borrego Springs, CA

No earthquake was likely felt in Borrego Springs in the 24 hours to 5:46 am PST (13:46 UTC). The last one was M 4.9, 145 km (90 mi) SE, at 10:27 am PST on 3 November 2026, estimated intensity II (weak) in town; 321 felt reports to USGS. Every earthquake near Borrego Springs

This page: a magnitude 3.9 earthquake was recorded 15 km (10 mi) north-northeast of Borrego Springs, CA, at 6:36 pm PDT on 25 April 2018 (01:36 UTC), 14 km deep. 101 people have reported feeling it to USGS.

USGS: 16km NNE of Borrego Springs, CA

40 km (25 mi) S of Indio, CA · 100 km (62 mi) NE of San Diego, CA

6:36 pm PDT, Apr 25, 2018 · · 14 km deep · released about 12 tons of TNT

Every earthquake near Borrego Springs Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Riverside County 48 kmSan Diego County 60 kmImperial County 95 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
6:36 pm PDT on 25 April 2018 ()
Where
15 km (10 mi) north-northeast of Borrego Springs, CA · earthquakes near Borrego Springs
Magnitude
M 3.9 (mw)
Depth
14 km below the surface
Felt
101 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
Riverside County, 48 km NE
Nearest mapped fault
San Jacinto 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 1611 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 91 km (57 mi) from the epicentre. In Borrego Springs, 15 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: Borrego Springs 15 km, intensity III · Mecca 30 km, intensity III · La Quinta 32 km, intensity III · Salton City 33 km, intensity III · Coachella 35 km, intensity III · Indio 39 km, intensity III · Palm Desert 39 km, intensity III · Anza 40 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 12 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 14,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 620× the energy of this one
  3. Magna, Utah 2020 M 5.7 440× the energy of this one
  4. This earthquake M 3.9 about 12 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 26× more

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 75 times the energy of this one.

Before 2016, the USGS record lists 14 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 The 1968 Borrego Mountain, California Earthquake · 29 km SE of this epicentre
  2. 6.4 The 1954 San Jacinto Fault, California Earthquake · 22 km ESE of this epicentre
  3. 6.0 16km WSW of Oasis, CA · 5 km ENE of this epicentre
  4. 5.7 Eastern San Diego County, California · 27 km SE of this epicentre
  5. 5.5 8km NNE of Ocotillo Wells, CA · 27 km SE 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 33.3797, -116.2983. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Riverside County, CA 48 km (30 mi) NE earthquakes near Riverside County
San Diego County, CA 60 km (37 mi) SW earthquakes near San Diego County
Imperial County, CA 95 km (59 mi) ESE earthquakes near Imperial County

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

Aftershocks so far

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

  1. 1.8 9km NE of Aguanga, CA
  2. 1.7 8km NE of Aguanga, CA
  3. 1.7 23km ESE of Anza, CA
  4. 1.6 23km ESE of Anza, CA
  5. 1.8 8km NE of Aguanga, CA
  6. 1.8 22km E of Julian, CA
  7. 2.0 9km NE of Aguanga, CA
  8. 1.5 7km E of Palomar Observatory, CA
  9. 2.8 10km ESE of Anza, CA
  10. 1.5 1km SW of Lake Henshaw, CA
  11. 2.0 9km NE of Aguanga, CA
  12. 2.5 5km E of Ocotillo Wells, CA
  13. 1.5 8km WSW of Anza, CA
  14. 1.7 8km NE of Aguanga, CA
  15. 2.4 8km NE of Aguanga, 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.