QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Yorba Linda, CA

No earthquake was likely felt in Yorba Linda in the 24 hours to 4:02 am PST (12:02 UTC). The last one was M 1.8, 5 km (3 mi) ESE, at 9:16 pm PST on 3 November 2026, estimated intensity II (weak) in town. Every earthquake near Yorba Linda

This page: a magnitude 1.8 earthquake was recorded 8 km (5 mi) east of Yorba Linda, CA, at 10:40 am PDT on 29 September 2018 (17:40 UTC), 7.1 km deep.

USGS: 8km E of Yorba Linda, CA

in Anaheim, CA

10:40 am PDT, Sep 29, 2018 · · 7.1 km deep · released about 13 lb of TNT

Every earthquake near Yorba Linda Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 23 kmLos Angeles County 61 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
10:40 am PDT on 29 September 2018 ()
Where
8 km (5 mi) east of Yorba Linda, CA · earthquakes near Yorba Linda
Magnitude
M 1.8 (ml)
Depth
7.1 km below the surface
Felt
no reports yet
Nearest
Orange County, 23 km SSW
Nearest mapped fault
Elsinore fault, 1 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 2942 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 11 km (7 mi) from the epicentre. In Yorba Linda, 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.

Likely felt in: Yorba Linda 8 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 13 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 4.4 on 2018-08-29 — about 8,800 times the energy of this one.

Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1933 Long Beach, California Earthquake · 38 km SW of this epicentre
  2. 6.2 3 km SE of San Bernardino, California · 49 km ENE of this epicentre
  3. 6.0 The 1910 Lake Elsinore, California Earthquake · 36 km ESE of this epicentre
  4. 5.9 The 1987 Whittier Narrows, California Earthquake · 38 km WNW of this epicentre
  5. 5.8 The 1991 Sierra Madre, California Earthquake · 50 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 33.8805, -117.7260. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 23 km (14 mi) SSW earthquakes near Orange County
Los Angeles County, CA 61 km (38 mi) NW earthquakes near Los Angeles County
San Diego County, CA 130 km (81 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

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

  1. 2.5 3km N of Muscoy, CA
  2. 1.7 7km NNE of San Dimas, CA
  3. 2.3 7km NNE of San Dimas, CA
  4. 1.6 11km WSW of Newport Beach, CA
  5. 1.6 4km NNW of Signal Hill, CA
  6. 1.6 3km SE of Home Gardens, CA
  7. 2.0 5km SE of Loma Linda, CA
  8. 1.7 4km W of Lake Elsinore, CA
  9. 1.9 3km SW of San Bernardino, CA
  10. 1.6 1km SSW of Colton, CA
  11. 1.5 5km SSE of Home Gardens, CA
  12. 1.5 2km NE of Whittier, CA
  13. 2.3 4km WNW of Devore, CA
  14. 1.5 4km WSW of Lytle Creek, CA
  15. 1.9 1km NNE of Loma Linda, 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.