QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

8km N of Glendora, CA

· 12 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Los Angeles County 35 kmOrange County 60 kmVentura County 117 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 1.8 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Los Angeles County, 35 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1675 days ago

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

How big was it?

This earthquake released about 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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.

Where

Epicentre 34.2078, -117.8767. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Los Angeles County, CA 35 km (22 mi) E of here earthquakes near Los Angeles County
Orange County, CA 60 km (37 mi) N of here earthquakes near Orange County
Ventura County, CA 117 km (72 mi) E of here earthquakes near Ventura County

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

Aftershocks so far

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

  1. 1.6 4km SE of Ontario, CA
  2. 2.3 3km N of Rancho Cucamonga, CA
  3. 2.0 6km NNW of Glen Avon, CA
  4. 1.5 8km NE of Rancho Cucamonga, CA
  5. 2.0 8km NE of Rancho Cucamonga, CA
  6. 1.7 8km NE of Rancho Cucamonga, CA
  7. 1.7 3km SW of Orange, CA
  8. 2.2 7km SSW of Pearblossom, CA
  9. 1.9 5km NNW of Vincent, CA
  10. 1.8 2km W of Lakewood, CA
  11. 2.0 5km SSW of Lytle Creek, CA
  12. 1.6 3km SE of South Whittier, CA
  13. 1.6 1km NE of Mira Loma, CA
  14. 1.6 6km NW of Glen Avon, CA
  15. 2.4 2km NW of Llano, 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 4.5 on 2020-09-19 — it released about 12,000 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.