QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Anza, CA

No earthquake was likely felt in Anza in the 24 hours to 4:56 pm PST (00:56 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 1.5 earthquake was recorded 9 km (6 mi) north of Anza, CA, at 8:20 am PST on 27 December 2016 (16:20 UTC), 12 km deep.

USGS: 10km N of Anza, CA

30 km (19 mi) SW of Cathedral City, CA · 101 km (63 mi) NNE of San Diego, CA

8:20 am PST, Dec 27, 2016 · · 12 km deep · released about 5.4 lb of TNT

10 km30 km60 km120 km N Riverside County 64 kmSan Diego County 69 kmOrange County 101 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
8:20 am PST on 27 December 2016 ()
Where
9 km (6 mi) north of Anza, CA · earthquakes near Anza
Magnitude
M 1.5 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Riverside County, 64 km E
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 3563 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, 9 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: Idyllwild, Idyllwild-Pine Cove, Valle Vista, Palm Springs, East Hemet, Cathedral City.

How big was it?

This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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

The largest earthquake within 50 km since 2016 was M 5.2 on 2016-06-10 — about 340,000 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1918 San Jacinto, California Earthquake · 30 km WNW of this epicentre
  2. 6.1 The 1992 Joshua Tree, California Earthquake · 49 km NE of this epicentre
  3. 6.0 16km WSW of Oasis, CA · 49 km ESE of this epicentre
  4. 6.0 The 1986 North Palm Springs, California Earthquake · 41 km N of this epicentre
  5. 5.4 20km NNW of Borrego Springs, CA · 32 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 33.6395, -116.6883. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Riverside County, CA 64 km (40 mi) E earthquakes near Riverside County
San Diego County, CA 69 km (43 mi) S earthquakes near San Diego County
Orange County, CA 101 km (63 mi) W earthquakes near Orange County

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

Aftershocks so far

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

  1. 2.0 8km NNW of Cabazon, CA
  2. 1.7 9km NE of Aguanga, CA
  3. 2.0 11km WSW of Morongo Valley, CA
  4. 2.9 14km N of Cabazon, CA
  5. 1.9 14km N of Cabazon, CA
  6. 1.8 13km NE of Thousand Palms, CA
  7. 1.5 16km NNW of Borrego Springs, CA
  8. 2.2 9km NE of Thousand Palms, CA
  9. 2.5 4km S of Banning, CA
  10. 1.8 7km NNE of Borrego Springs, CA
  11. 1.6 8km NE of Aguanga, CA
  12. 1.7 9km NE of Aguanga, CA
  13. 1.9 4km ESE of Palomar Observatory, CA
  14. 1.9 6km WNW of Lake Henshaw, CA
  15. 1.7 4km N of Cabazon, 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.