QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

Earthquake near Westmorland, CA

No earthquake was likely felt in Westmorland in the 24 hours to 10:12 pm PST (06:12 UTC). The last one was M 4.9, 79 km (49 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 Westmorland

This page: a magnitude 3.2 earthquake was recorded 3 km (2 mi) east of Westmorland, CA, at 6:05 pm PDT on 30 September 2020 (01:05 UTC), 7.0 km deep.

USGS: 3km E of Westmorland, CA

6:05 pm PDT, Sep 30, 2020 · · 7.0 km deep · released about 1.1 tons of TNT

Every earthquake near Westmorland Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Imperial County 21 kmRiverside County 86 kmSan Diego County 111 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
6:05 pm PDT on 30 September 2020 ()
Where
3 km (2 mi) east of Westmorland, CA · earthquakes near Westmorland
Magnitude
M 3.2 (ml)
Depth
7.0 km below the surface
Felt
no reports yet
Nearest
Imperial County, 21 km E
Nearest mapped fault
Brawley Seismic Zone, 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 2063 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 48 km (30 mi) from the epicentre. In Westmorland, 3 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: Brawley 9 km, intensity III · Calipatria 11 km, intensity III · Imperial 22 km, intensity II · El Centro 28 km, intensity II · Holtville 32 km, intensity II · Calexico 41 km, intensity II · Salton City 45 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.1 tons 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 6.7 160,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,200× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,100× the energy of this one
  4. This earthquake M 3.2 about 1.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.2× 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 350 times the energy of this one.

Before 2016, the USGS record lists 37 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1940 Imperial Valley, California Earthquake · 29 km SE of this epicentre
  2. 6.6 The 1942 Fish Creek Mountains, California Earthquake · 20 km WSW of this epicentre
  3. 6.6 The 1987 Superstition Hills, California Earthquake · 25 km W of this epicentre
  4. 6.4 The 1979 Imperial Valley Earthquake, California-Baja California · 47 km SSE of this epicentre
  5. 6.3 The 1906 Imperial Valley, California Earthquake · 18 km SSE 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 33.0427, -115.5850. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Imperial County, CA 21 km (13 mi) E earthquakes near Imperial County
Riverside County, CA 86 km (53 mi) NNW earthquakes near Riverside County
San Diego County, CA 111 km (69 mi) W earthquakes near San Diego County

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

Aftershocks so far

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

  1. 1.5 4km NNE of Westmorland, CA
  2. 1.7 2km E of Westmorland, CA
  3. 1.8 4km NE of Westmorland, CA
  4. 1.7 3km ENE of Westmorland, CA
  5. 1.5 3km ESE of Westmorland, CA
  6. 1.7 4km ENE of Westmorland, CA
  7. 2.0 4km NE of Westmorland, CA
  8. 2.4 3 km NE of Westmorland, California
  9. 1.8 3km E of Westmorland, CA
  10. 1.7 3km E of Westmorland, CA
  11. 1.9 3km ENE of Westmorland, CA
  12. 1.9 4km ESE of Westmorland, CA
  13. 1.9 3km ENE of Westmorland, CA
  14. 2.0 4km E of Westmorland, CA
  15. 1.5 5km ENE of Westmorland, 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.