QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

Earthquake near Holtville, CA

No earthquake was likely felt in Holtville in the 24 hours to 8:37 am PST (16:37 UTC). The last one was M 4.9, 46 km (29 mi) SSE, at 10:27 am PST on 3 November 2026, estimated intensity III (weak) in town; 321 felt reports to USGS. Every earthquake near Holtville

This page: a magnitude 3.2 earthquake was recorded 7 km (4 mi) southwest of Holtville, CA, at 8:28 pm PDT on 7 April 2021 (03:28 UTC), 16 km deep. 3 people have reported feeling it to USGS.

USGS: 6km SW of Holtville, CA

8:28 pm PDT, Apr 7, 2021 · · 16 km deep · released about 1,900 lb of TNT

Every earthquake near Holtville Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Imperial County 30 kmRiverside County 118 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
8:28 pm PDT on 7 April 2021 ()
Where
7 km (4 mi) southwest of Holtville, CA · earthquakes near Holtville
Magnitude
M 3.2 (ml)
Depth
16 km below the surface
Felt
3 reports · strongest reported intensity II
Nearest
Imperial County, 30 km NNE
Nearest mapped fault
Imperial 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 1979 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 44 km (27 mi) from the epicentre. In Holtville, 7 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: Holtville 7 km, intensity III · El Centro 12 km, intensity III · Calexico 12 km, intensity III · Imperial 15 km, intensity II · Brawley 24 km, intensity II · Calipatria 39 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
  4. This earthquake M 3.2 about 1,900 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 2× 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 4.9 on 2020-10-01 — about 390 times the energy of this one.

Before 2016, the USGS record lists 44 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1940 Imperial Valley, California Earthquake · 9 km NE of this epicentre
  2. 6.6 The 1942 Fish Creek Mountains, California Earthquake · 39 km NW of this epicentre
  3. 6.6 The 1987 Superstition Hills, California Earthquake · 47 km NW of this epicentre
  4. 6.4 The 1979 Imperial Valley Earthquake, California-Baja California · 14 km SSE of this epicentre
  5. 6.3 The 1906 Imperial Valley, California Earthquake · 15 km NNW 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 32.7777, -115.4377. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Imperial County, CA 30 km (19 mi) NNE earthquakes near Imperial County
Riverside County, CA 118 km (73 mi) NNW earthquakes near Riverside County

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

Aftershocks so far

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

  1. 2.4 6km SW of Progreso, B.C., MX
  2. 1.6 4km NNE of Westmorland, CA
  3. 1.5 16km E of Ocotillo, CA
  4. 1.5 16km E of Ocotillo, CA
  5. 1.6 16km E of Ocotillo, CA
  6. 1.5 12km WNW of Calipatria, CA
  7. 1.9 16km E of Ocotillo, CA
  8. 1.9 17km E of Ocotillo, CA
  9. 1.5 16km E of Ocotillo, CA
  10. 1.6 21km ESE of Ocotillo, CA
  11. 1.6 17km E of Ocotillo, CA
  12. 2.3 16km E of Ocotillo, CA
  13. 2.1 14km WNW of Calipatria, CA
  14. 1.7 14km WNW of Calipatria, CA
  15. 2.5 3km SW of Brawley, 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.