QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Anza, CA

No earthquake was likely felt in Anza in the 24 hours to 4:15 am PST (12:15 UTC). The last one was M 2.6, 17 km (10 mi) S, at 10:44 pm PST on 5 November 2026, estimated intensity II (weak) in town; 7 felt reports to USGS. Every earthquake near Anza

This page: a magnitude 1.6 earthquake was recorded 17 km (11 mi) east-southeast of Anza, CA, at 8:44 pm PDT on 31 May 2016 (03:44 UTC), 13 km deep.

USGS: 17km ESE of Anza, CA

93 km (58 mi) NE of San Diego, CA · 33 km (20 mi) SSW of Palm Desert, CA

8:44 pm PDT, May 31, 2016 · · 13 km deep · released about 7.3 lb of TNT

10 km30 km60 km120 km N San Diego County 55 kmRiverside County 56 kmImperial County 118 kmOrange County 119 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
8:44 pm PDT on 31 May 2016 ()
Where
17 km (11 mi) east-southeast of Anza, CA · earthquakes near Anza
Magnitude
M 1.6 (ml)
Depth
13 km below the surface
Felt
no reports yet
Nearest
San Diego County, 55 km SSW
Nearest mapped fault
San Jacinto fault, 2 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 3816 days ago

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 Anza, 17 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.

Earthquakes near other towns within 30 km: Borrego Springs, La Quinta.

How big was it?

This earthquake released about 7.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1954 San Jacinto Fault, California Earthquake · 45 km ESE of this epicentre
  2. 6.0 16km WSW of Oasis, CA · 26 km ESE of this epicentre
  3. 5.7 Eastern San Diego County, California · 49 km SE of this epicentre
  4. 5.5 8km NNE of Ocotillo Wells, CA · 49 km SE of this epicentre
  5. 5.5 1km ENE of Borrego Springs, CA · 28 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 33.4727, -116.5190. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Diego County, CA 55 km (34 mi) SSW earthquakes near San Diego County
Riverside County, CA 56 km (35 mi) ENE earthquakes near Riverside County
Imperial County, CA 118 km (74 mi) ESE earthquakes near Imperial County
Orange County, CA 119 km (74 mi) WNW earthquakes near Orange 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. 2.0 20km ESE of Anza, CA
  2. 1.9 22km ESE of Anza, CA
  3. 1.9 20km ESE of Anza, CA
  4. 1.8 11km ESE of Anza, CA
  5. 1.8 22km ESE of Anza, CA
  6. 1.6 24km SSW of La Quinta, CA
  7. 1.8 22km N of Borrego Springs, CA
  8. 2.1 22km N of Borrego Springs, CA
  9. 2.0 22km N of Borrego Springs, CA
  10. 1.6 24km SSW of La Quinta, CA
  11. 1.6 23km ESE of Anza, CA
  12. 2.6 21km NNW of Borrego Springs, CA
  13. 1.6 22km ESE of Anza, CA
  14. 3.1 22km ESE of Anza, CA
  15. 2.0 23km NNW of Borrego Springs, 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.