Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Glendora, CA
No earthquake was likely felt in Glendora in the 24 hours to 2:20 pm PST (22:20 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 1.8 earthquake was recorded 8 km (5 mi) north of Glendora, CA, at 11:47 am PST on 21 February 2022 (19:47 UTC), 12 km deep.
USGS: 8km N of Glendora, CA
7 km (5 mi) NNW of Glendora, CA · 53 km (33 mi) ENE of Los Angeles, CA
- When
- 11:47 am PST on 21 February 2022 ()
- Where
- 8 km (5 mi) north of Glendora, CA · earthquakes near Glendora
- Magnitude
- M 1.8 (ml)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest
- Los Angeles County, 35 km W
- Nearest mapped fault
- Sierra Madre fault, 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 1721 days ago
Earthquake alerts for Glendora, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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, 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: Azusa, Citrus, Bradbury, Duarte, Charter Oak, Irwindale.
How big was it?
This earthquake released about 16 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.
- Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
- Magna, Utah 2020 M 5.7 660,000× the energy of this one
- Around the size people start to feel M 3.0 59× the energy of this one
- This earthquake M 1.8 about 16 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 4.5 on 2020-09-19 — about 12,000 times the energy of this one.
Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:
- 5.9 The 1987 Whittier Narrows, California Earthquake · 25 km SW of this epicentre
- 5.8 The 1991 Sierra Madre, California Earthquake · 13 km WNW of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 18 km ESE of this epicentre
- 5.4 5km S of Chino Hills, CA · 31 km SSE of this epicentre
- 5.2 3km W of Lytle Creek, CA · 32 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 34.2078, -117.8767. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Los Angeles County, CA | 35 km (22 mi) | W | earthquakes near Los Angeles County |
| Orange County, CA | 60 km (37 mi) | S | earthquakes near Orange County |
| Ventura County, CA | 117 km (72 mi) | W | earthquakes near Ventura County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
34 earthquakes have been recorded within 50 km since this one.
- 1.6 4km SE of Ontario, CA
- 2.3 3km N of Rancho Cucamonga, CA
- 2.0 6km NNW of Glen Avon, CA
- 1.5 8km NE of Rancho Cucamonga, CA
- 2.0 8km NE of Rancho Cucamonga, CA
- 1.7 8km NE of Rancho Cucamonga, CA
- 1.7 3km SW of Orange, CA
- 2.2 7km SSW of Pearblossom, CA
- 1.9 5km NNW of Vincent, CA
- 1.8 2km W of Lakewood, CA
- 2.0 5km SSW of Lytle Creek, CA
- 1.6 3km SE of South Whittier, CA
- 1.6 1km NE of Mira Loma, CA
- 1.6 6km NW of Glen Avon, CA
- 2.4 2km NW of Llano, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.