quarry blast · reviewed by a seismologist
M 1.5ml
Earthquake near Home Gardens, CA
No earthquake was likely felt in Home Gardens in the 24 hours to 5:16 am PST (13:16 UTC). The last one was M 1.6, 7 km (4 mi) SSE, at 1:57 pm PST on 6 November 2026, estimated intensity II (weak) in town. Every earthquake near Home Gardens
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.5 quarry blast was recorded 12 km (7 mi) southeast of Home Gardens, CA, at 3:20 pm PST on 9 March 2021 (23:20 UTC), less than 1 km deep. 1 person has reported feeling it to USGS.
USGS: 12km SE of Home Gardens, CA
14 km (8 mi) ESE of Corona, CA · 93 km (58 mi) ESE of Los Angeles, CA
- When
- 3:20 pm PST on 9 March 2021 ()
- Where
- 12 km (7 mi) southeast of Home Gardens, CA · earthquakes near Home Gardens
- Magnitude
- M 1.5 (ml)
- Depth
- -0.7 km below the surface
- Felt
- 1 report · strongest reported intensity I
- Nearest
- Orange County, 34 km WSW
- Nearest mapped fault
- Elsinore fault, 6 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 2073 days ago
Earthquake alerts for Home Gardens, 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 10 km (6 mi) from the epicentre. In Home Gardens, 12 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: El Cerrito Corona, Woodcrest, Mead Valley, Corona, Good Hope, Meadowbrook.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 5.4 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.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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 21,000 times the energy of this one.
Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 The 1918 San Jacinto, California Earthquake · 43 km E of this epicentre
- 6.2 3 km SE of San Bernardino, California · 36 km NNE of this epicentre
- 6.0 The 1910 Lake Elsinore, California Earthquake · 12 km SSE of this epicentre
- 5.5 The 1990 Upland, California Earthquake · 45 km NNW of this epicentre
- 5.4 5km S of Chino Hills, CA · 34 km WNW 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 33.8000, -117.4383. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 34 km (21 mi) | WSW | earthquakes near Orange County |
| Los Angeles County, CA | 88 km (55 mi) | WNW | earthquakes near Los Angeles County |
| San Diego County, CA | 106 km (66 mi) | SE | earthquakes near San Diego County |
| San Bernardino County, CA | 165 km (102 mi) | NE | earthquakes near San Bernardino 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.
- 1.8 6km NNE of Fontana, CA
- 1.6 4km NNE of San Bernardino, CA
- 1.5 4km SE of Loma Linda, CA
- 1.8 5km E of Yucaipa, CA
- 2.1 4km SE of Loma Linda, CA
- 1.6 4km SE of Chino Hills, CA
- 3.0 4km SE of Loma Linda, CA
- 1.7 5km SSE of Home Gardens, CA
- 1.6 11km ENE of North Tustin, CA
- 2.2 6km NW of Mira Loma, CA
- 1.6 5km N of Lake Elsinore, CA
- 1.5 3km E of Fontana, CA
- 1.6 6km SE of Loma Linda, CA
- 1.5 3km NNW of Fontana, CA
- 2.6 1km N of Yucaipa, 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.