QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Glendora, CA

No earthquake was likely felt in Glendora in the 24 hours to 4:37 am PST (12:37 UTC). The last one was M 3.6, 64 km (40 mi) WSW, at 8:40 am PDT on 27 September 2026, estimated intensity II (weak) in town; 1,735 felt reports to USGS. Every earthquake near Glendora

This page: a magnitude 1.5 earthquake was recorded 17 km (11 mi) north-northeast of Glendora, CA, at 2:08 am PDT on 2 August 2018 (09:08 UTC), 7.1 km deep.

USGS: 17km NNE of Glendora, CA

62 km (39 mi) ENE of Los Angeles, CA · 16 km (10 mi) N of Glendora, CA

2:08 am PDT, Aug 2, 2018 · · 7.1 km deep · released about 5.6 lb of TNT

10 km30 km60 km120 km N Los Angeles County 42 kmOrange County 68 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
2:08 am PDT on 2 August 2018 ()
Where
17 km (11 mi) north-northeast of Glendora, CA · earthquakes near Glendora
Magnitude
M 1.5 (ml)
Depth
7.1 km below the surface
Felt
no reports yet
Nearest
Los Angeles County, 42 km WSW
Nearest mapped fault
San Gabriel fault, 3 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 3024 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 7 km (4 mi) from the epicentre. In Glendora, 17 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: Wrightwood, Azusa, San Dimas, Citrus, San Antonio Heights, Charter Oak.

How big was it?

This earthquake released about 5.6 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 2,700,000× 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 5.6 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 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.9 The 1987 Whittier Narrows, California Earthquake · 35 km SW of this epicentre
  2. 5.8 The 1991 Sierra Madre, California Earthquake · 17 km W of this epicentre
  3. 5.5 The 1990 Upland, California Earthquake · 19 km SE of this epicentre
  4. 5.4 5km S of Chino Hills, CA · 38 km S of this epicentre
  5. 5.2 3km W of Lytle Creek, CA · 26 km E 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 34.2868, -117.8143. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Los Angeles County, CA 42 km (26 mi) WSW earthquakes near Los Angeles County
Orange County, CA 68 km (42 mi) S earthquakes near Orange County
Kern County, CA 144 km (90 mi) NW earthquakes near Kern County

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

Aftershocks so far

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

  1. 1.6 7km NW of Rancho Cucamonga, CA
  2. 1.9 7km S of Lytle Creek, CA
  3. 2.1 4km ENE of Lytle Creek, CA
  4. 2.9 4km N of La Verne, CA
  5. 1.6 1km ESE of Maywood, CA
  6. 1.8 10km NE of Lake Los Angeles, CA
  7. 2.4 16km NE of Lake Los Angeles, CA
  8. 3.0 9km WSW of Wrightwood, CA
  9. 1.9 4km N of La Verne, CA
  10. 1.8 8km E of Yorba Linda, CA
  11. 1.7 4km SSE of Devore, CA
  12. 1.8 3km SE of Vincent, CA
  13. 1.9 3km NE of Vincent, CA
  14. 1.7 9km S of Quartz Hill, CA
  15. 2.4 3km NNW of La Verne, 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.