QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near North Tustin, CA

No earthquake was likely felt in North Tustin in the 24 hours to 2:29 am PST (10:29 UTC). The last one was M 3.2, 36 km (22 mi) W, at 12:44 am PDT on 9 October 2026, estimated intensity II (weak) in town; 1,090 felt reports to USGS. Every earthquake near North Tustin

This page: a magnitude 1.6 earthquake was recorded 8 km (5 mi) east-southeast of North Tustin, CA, at 1:30 am PDT on 23 May 2018 (08:30 UTC), 13 km deep.

USGS: 8km ESE of North Tustin, CA

9 km (6 mi) E of Tustin, CA · 71 km (44 mi) ESE of Los Angeles, CA

1:30 am PDT, May 23, 2018 · · 13 km deep · released about 7.3 lb of TNT

Every earthquake near North Tustin Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 10 kmLos Angeles County 71 kmSan Diego 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
1:30 am PDT on 23 May 2018 ()
Where
8 km (5 mi) east-southeast of North Tustin, CA · earthquakes near North Tustin
Magnitude
M 1.6 (ml)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Orange County, 10 km SW
Nearest mapped fault
San Joaquin Hills thrust, 11 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 it was probably too small to be felt, even directly above it. In North Tustin, 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: Tustin, Lake Forest, Villa Park, Irvine, Orange, Trabuco Canyon.

How big was it?

This earthquake released about 7.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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.

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 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1933 Long Beach, California Earthquake · 30 km WSW of this epicentre
  2. 6.0 The 1910 Lake Elsinore, California Earthquake · 29 km E of this epicentre
  3. 5.9 The 1987 Whittier Narrows, California Earthquake · 49 km NW of this epicentre
  4. 5.5 The 1990 Upland, California Earthquake · 44 km N of this epicentre
  5. 5.4 5km S of Chino Hills, CA · 23 km NNW 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 33.7468, -117.7102. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 10 km (6 mi) SW earthquakes near Orange County
Los Angeles County, CA 71 km (44 mi) NW earthquakes near Los Angeles County
San Diego County, CA 118 km (73 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

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

  1. 1.8 2km NNW of La Verne, CA
  2. 3.4 4km N of La Verne, CA
  3. 4.4 4km N of La Verne, CA
  4. 1.6 12km SSE of San Pedro, CA
  5. 2.5 2km NE of Villa Park, CA
  6. 1.9 4km SE of Home Gardens, CA
  7. 1.7 1km ENE of Yorba Linda, CA
  8. 1.5 4km SSE of Home Gardens, CA
  9. 2.3 3km SSE of Charter Oak, CA
  10. 1.5 2km SE of Home Gardens, CA
  11. 2.8 3km NW of Fontana, CA
  12. 2.6 13km NE of Trabuco Canyon, CA
  13. 2.4 3km NNE of Rancho Cucamonga, CA
  14. 1.6 1km SSE of Placentia, CA
  15. 1.9 9km SSW of Wildomar, 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.