QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

2 km ESE of Rossmoor, CA

· 10 km deep · released about 9.3 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 29 kmLos Angeles County 50 kmVentura County 118 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 1.7 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Orange County, 29 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 622 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 9.3 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 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 100× the energy of this one
  4. This earthquake M 1.7 about 9.3 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.

Where

Epicentre 33.7788, -118.0625. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Orange County, CA 29 km (18 mi) WNW of here earthquakes near Orange County
Los Angeles County, CA 50 km (31 mi) SSE of here earthquakes near Los Angeles County
Ventura County, CA 118 km (73 mi) ESE of here earthquakes near Ventura County
San Diego County, CA 146 km (91 mi) NW of here earthquakes near San Diego County

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

Aftershocks so far

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

  1. 2.1 6 km WSW of Norco, CA
  2. 2.2 3 km SSW of Yorba Linda, CA
  3. 1.6 3 km SSW of Yorba Linda, CA
  4. 1.7 1 km N of Universal City, CA
  5. 2.7 7 km SW of Seal Beach, CA
  6. 1.6 5 km ESE of Yorba Linda, CA
  7. 1.8 3 km SSE of Cudahy, CA
  8. 2.0 1 km E of Palos Verdes Estates, CA
  9. 1.6 1 km NW of Rolling Hills Estates, CA
  10. 1.6 3 km N of Placentia, CA
  11. 2.1 5 km ESE of Yorba Linda, CA
  12. 1.7 2 km N of Universal City, CA
  13. 1.6 4 km SE of Rowland Heights, CA
  14. 1.6 2 km NNW of Universal City, CA
  15. 2.1 1 km N of Manhattan Beach, 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 21,000 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.