QuakeIndex

Earthquake · reviewed by a seismologist

M 4.9mw

17km ESE of Anza, CA

· 10 km deep · released about 300 tons of TNT

10 km30 km60 km120 km N Riverside County 54 kmSan Diego County 58 kmImperial County 118 kmOrange County 120 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
Magnitude
M 4.9 (mw)
Depth
10 km below the surface
Felt
14100 reports · strongest reported intensity IV
Measured shaking
intensity VII (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Riverside County, 54 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 250 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 14100 people have reported feeling it to USGS.

How big was it?

This earthquake released about 300 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 560× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 25× the energy of this one
  3. Magna, Utah 2020 M 5.7 18× the energy of this one
  4. This earthquake M 4.9 about 300 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 640× 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.

Where

Epicentre 33.4895, -116.5063. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Riverside County, CA 54 km (33 mi) WSW of here earthquakes near Riverside County
San Diego County, CA 58 km (36 mi) NNE of here earthquakes near San Diego County
Imperial County, CA 118 km (73 mi) WNW of here earthquakes near Imperial County
Orange County, CA 120 km (74 mi) E of here 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. 1.5 16km ESE of Anza, CA
  2. 1.6 16km ESE of Anza, CA
  3. 3.6 16km ESE of Anza, CA
  4. 1.7 15km ESE of Anza, CA
  5. 1.9 16km ESE of Anza, CA
  6. 1.7 17km ESE of Anza, CA
  7. 1.8 18km ESE of Anza, CA
  8. 2.2 17km ESE of Anza, CA
  9. 1.8 16km ESE of Anza, CA
  10. 3.1 16km ESE of Anza, CA
  11. 2.1 17km ESE of Anza, CA
  12. 1.6 15km ESE of Anza, CA
  13. 2.1 16km ESE of Anza, CA
  14. 1.7 17km ESE of Anza, CA
  15. 2.3 18km ESE of Anza, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.2 on 2016-06-10 — it released about 3 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.