QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

10km NNW of Alpine, CA

· 15 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Diego County 13 kmRiverside 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 1.8 (ml)
Depth
15 km below the surface
Felt
12 reports · strongest reported intensity III
Nearest
San Diego County, 13 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1972 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 12 people have reported feeling it to USGS.

How big was it?

This earthquake released about 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× the energy of this one
  4. This earthquake M 1.8 about 14 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 32.9162, -116.8218. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Diego County, CA 13 km (8 mi) SSW of here earthquakes near San Diego County
Riverside County, CA 118 km (73 mi) SW of here earthquakes near Riverside County
Orange County, CA 123 km (76 mi) SE of here earthquakes near Orange County

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

Aftershocks so far

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

  1. 1.6 5km SE of Chula Vista, CA
  2. 1.6 11km NE of Julian, CA
  3. 1.6 6km NNW of Lakeside, CA
  4. 1.6 6km NE of Rancho San Diego, CA
  5. 1.8 3km ESE of Julian, CA
  6. 1.6 6km NNW of Lakeside, CA
  7. 2.6 10km S of Borrego Springs, CA
  8. 1.5 11km NW of Julian, CA
  9. 1.8 5km NNE of San Ysidro, CA
  10. 1.6 10km S of Borrego Springs, CA
  11. 1.6 18km NNE of Pine Valley, CA
  12. 1.6 4km SE of Chula Vista, CA
  13. 1.7 21km E of Julian, CA
  14. 2.7 2km WNW of Lake Henshaw, CA
  15. 1.6 6km NNW of Lakeside, 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.