QuakeIndex

quarry blast · reviewed by a seismologist

M 1.5ml

4 km NNE of Rancho Penasquitos, California

· -0.2 km deep · released about 5.7 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Diego County 30 kmOrange County 99 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 1.5 (ml)
Depth
-0.2 km below the surface
Felt
no reports yet
Nearest
San Diego County, 30 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3421 days ago

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

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 32.9915, -117.0942. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Diego County, CA 30 km (19 mi) W of here earthquakes near San Diego County
Orange County, CA 99 km (62 mi) SE of here earthquakes near Orange County
Riverside County, CA 130 km (81 mi) SW of here earthquakes near Riverside County

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

Aftershocks so far

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

  1. 1.5 7km E of Palomar Observatory, CA
  2. 1.5 1km SW of Lake Henshaw, CA
  3. 1.6 1km WNW of San Ysidro, CA
  4. 1.6 9km E of Pala, CA
  5. 2.0 4km W of Palomar Observatory, CA
  6. 1.6 6km NNW of Lakeside, CA
  7. 1.6 2km NNW of Julian, CA
  8. 1.8 10km ENE of Pala, CA
  9. 1.6 3km WNW of Julian, CA
  10. 1.5 6km NNW of Lakeside, CA
  11. 1.9 2km SW of Lake Henshaw, CA
  12. 1.6 4km ENE of Rancho San Diego, CA
  13. 1.9 1km SW of Lake Henshaw, CA
  14. 2.3 2km S of San Pasqual, 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.