QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Anza, CA

No earthquake was likely felt in Anza in the 24 hours to 12:22 pm PST (20:22 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 1.7 earthquake was recorded 13 km (8 mi) southeast of Anza, CA, at 3:36 pm PST on 19 December 2018 (23:36 UTC), 11 km deep.

USGS: 13km SE of Anza, CA

88 km (55 mi) NE of San Diego, CA · 37 km (23 mi) SW of Palm Desert, CA

3:36 pm PST, Dec 19, 2018 · · 11 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N San Diego County 52 kmRiverside County 62 kmOrange County 113 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
3:36 pm PST on 19 December 2018 ()
Where
13 km (8 mi) southeast of Anza, CA · earthquakes near Anza
Magnitude
M 1.7 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
San Diego County, 52 km SSW
Nearest mapped fault
San Jacinto fault, 5 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 2885 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 7 km (4 mi) from the epicentre. In Anza, 13 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: Aguanga.

How big was it?

This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× the energy of this one
  4. This earthquake M 1.7 about 12 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 150,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1918 San Jacinto, California Earthquake · 49 km NW of this epicentre
  2. 6.0 16km WSW of Oasis, CA · 32 km ESE of this epicentre
  3. 5.5 1km ENE of Borrego Springs, CA · 31 km SE of this epicentre
  4. 5.4 20km NNW of Borrego Springs, CA · 12 km ESE of this epicentre
  5. 5.3 6km SSE of Hemet, CA · 42 km NW 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 33.4645, -116.5878. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Diego County, CA 52 km (32 mi) SSW earthquakes near San Diego County
Riverside County, CA 62 km (38 mi) ENE earthquakes near Riverside County
Orange County, CA 113 km (70 mi) WNW earthquakes near Orange County
Imperial County, CA 124 km (77 mi) ESE earthquakes near Imperial County

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

Aftershocks so far

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

  1. 1.9 15km ESE of Julian, CA
  2. 2.6 16km S of La Quinta, CA
  3. 2.5 8km NNW of Borrego Springs, CA
  4. 1.9 8km NNW of Borrego Springs, CA
  5. 1.9 8km NNW of Borrego Springs, CA
  6. 1.5 19km ESE of Anza, CA
  7. 1.7 16km ESE of Julian, CA
  8. 2.1 10km SE of Valle Vista, CA
  9. 1.9 9km SE of Valle Vista, CA
  10. 1.8 8km ENE of Julian, CA
  11. 1.7 4km WNW of Borrego Springs, CA
  12. 1.8 8km NE of Aguanga, CA
  13. 1.6 9km NE of Aguanga, CA
  14. 2.4 8km NE of Aguanga, CA
  15. 1.8 18km SSW of Oasis, 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.