QuakeIndex

chemical explosion · reviewed by a seismologist

M 1.8ml

Earthquake near Irvine, CA

No earthquake was likely felt in Irvine in the 24 hours to 4:47 am PST (12:47 UTC). The last one was M 3.2, 36 km (22 mi) WNW, at 12:44 am PDT on 9 October 2026, estimated intensity II (weak) in town; 1,090 felt reports to USGS. Every earthquake near Irvine

No: USGS classifies this as a chemical explosion, not an earthquake. A magnitude 1.8 chemical explosion was recorded in Irvine, CA, at 7:37 pm PDT on 27 June 2018 (02:37 UTC), less than 1 km deep.

USGS: 4km WSW of Irvine, CA

6 km (3 mi) W of Irvine, CA · 66 km (41 mi) SE of Los Angeles, CA

7:37 pm PDT, Jun 27, 2018 · · 0.0 km deep · released about 14 lb of TNT

Every earthquake near Irvine Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 5 kmLos Angeles County 71 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
7:37 pm PDT on 27 June 2018 ()
Where
in Irvine, CA · earthquakes near Irvine
Magnitude
M 1.8 (ml)
Depth
0.0 km below the surface
Felt
no reports yet
Nearest
Orange County, 5 km E
Nearest mapped fault
San Joaquin Hills thrust, 2 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 3030 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 13 km (8 mi) from the epicentre. 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.

Likely felt in: Irvine in town, intensity II · Tustin 9 km, intensity II · Costa Mesa 9 km, intensity II · Santa Ana 9 km, intensity II · Newport Beach 11 km, intensity II · North Tustin 11 km, intensity II · Fountain Valley 12 km, intensity II · Laguna Hills 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

USGS catalogues this as chemical explosion, not an earthquake.

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 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× 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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1933 Long Beach, California Earthquake · 16 km WSW of this epicentre
  2. 6.0 The 1910 Lake Elsinore, California Earthquake · 40 km E of this epicentre
  3. 5.9 The 1987 Whittier Narrows, California Earthquake · 49 km NNW of this epicentre
  4. 5.4 5km S of Chino Hills, CA · 32 km N of this epicentre
  5. 5.3 7km W of Newport Beach, CA · 17 km WSW 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 33.6688, -117.8300. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 5 km (3 mi) E earthquakes near Orange County
Los Angeles County, CA 71 km (44 mi) NW earthquakes near Los Angeles County
San Diego County, CA 121 km (75 mi) SE 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. 1.6 1km ESE of Maywood, CA
  2. 1.7 8km SSE of Home Gardens, CA
  3. 1.6 5km SE of Home Gardens, CA
  4. 1.5 7km SSE of Home Gardens, CA
  5. 1.6 12km SSE of Corona, CA
  6. 2.1 8km W of Newport Beach, CA
  7. 2.4 7km W of Newport Beach, CA
  8. 2.1 9km ENE of North Tustin, CA
  9. 1.8 8km E of Yorba Linda, CA
  10. 1.9 2km WNW of Orange, CA
  11. 1.7 3km W of Orange, CA
  12. 1.9 5km SE of Home Gardens, CA
  13. 2.0 14km NW of Fallbrook, CA
  14. 1.9 9km ENE of Villa Park, CA
  15. 1.6 4km SE of Home Gardens, 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.