QuakeIndex

quarry blast · reviewed by a seismologist

M 1.5mh

Earthquake near San Juan Capistrano, CA

No earthquake was likely felt in San Juan Capistrano in the 24 hours to 7:04 am PST (15:04 UTC). The last one was M 3.5, 36 km (22 mi) SW, at 1:22 pm PDT on 5 October 2026, estimated intensity II (weak) in town; 126 felt reports to USGS. Every earthquake near San Juan Capistrano

No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.5 quarry blast was recorded 8 km (5 mi) east of San Juan Capistrano, CA, at 3:34 pm PDT on 31 July 2024 (22:34 UTC), less than 1 km deep.

USGS: 8 km E of San Juan Capistrano, CA

6 km (4 mi) NNE of San Clemente, CA · 96 km (60 mi) SE of Los Angeles, CA

3:34 pm PDT, Jul 31, 2024 · · -0.5 km deep · released about 5.4 lb of TNT

10 km30 km60 km120 km N Orange County 27 kmSan Diego County 91 kmLos Angeles County 100 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
3:34 pm PDT on 31 July 2024 ()
Where
8 km (5 mi) east of San Juan Capistrano, CA · earthquakes near San Juan Capistrano
Magnitude
M 1.5 (mh)
Depth
-0.5 km below the surface
Felt
no reports yet
Nearest
Orange County, 27 km NW
Nearest mapped fault
Newport-Inglewood-Rose Canyon fault, 14 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 736 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In San Juan Capistrano, 8 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: San Clemente, Ladera Ranch, Las Flores, Dana Point, Coto De Caza, Laguna Niguel.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 5.4 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 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.1 on 2024-05-01 — about 8,200 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1933 Long Beach, California Earthquake · 42 km WNW of this epicentre
  2. 6.0 The 1910 Lake Elsinore, California Earthquake · 28 km NE of this epicentre
  3. 5.3 7km W of Newport Beach, CA · 42 km WNW of this epicentre
  4. 5.2 8km ENE of Trabuco Canyon, CA · 23 km NNE of this epicentre
  5. 5.0 Near Lake Elsinore, California · 28 km NE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 33.4963, -117.5793. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 27 km (17 mi) NW earthquakes near Orange County
San Diego County, CA 91 km (57 mi) SE earthquakes near San Diego County
Los Angeles County, CA 100 km (62 mi) NW earthquakes near Los Angeles 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. 2.6 27 km WSW of Dana Point, CA
  2. 2.6 27 km WSW of Dana Point, CA
  3. 2.8 27 km WSW of Dana Point, CA
  4. 1.7 5 km SSE of Home Gardens, CA
  5. 1.8 4 km SSE of Home Gardens, CA
  6. 2.1 9 km NNE of Trabuco Canyon, CA
  7. 1.7 2 km NE of Yorba Linda, CA
  8. 1.6 8 km SSE of Home Gardens, CA
  9. 1.7 5 km SSE of Home Gardens, CA
  10. 1.5 1 km NE of Yorba Linda, CA
  11. 1.6 3 km W of Irvine, CA
  12. 1.5 4 km SE of Home Gardens, CA
  13. 1.5 6 km ENE of Villa Park, CA
  14. 1.6 2 km N of Orange, CA
  15. 1.6 2 km WNW of Villa Park, 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.