quarry blast · reviewed by a seismologist
M 1.6ml
Earthquake near Calipatria, CA
No earthquake was likely felt in Calipatria in the 24 hours to 10:44 am PST (18:44 UTC). The last one was M 4.9, 83 km (52 mi) SSE, at 10:27 am PST on 3 November 2026, estimated intensity III (weak) in town; 321 felt reports to USGS. Every earthquake near Calipatria
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.6 quarry blast was recorded 48 km (30 mi) east of Calipatria, CA, at 3:36 pm PDT on 23 April 2018 (22:36 UTC), less than 1 km deep.
USGS: 46km NE of Holtville, CA
77 km (48 mi) NW of Yuma, AZ
- When
- 3:36 pm PDT on 23 April 2018 ()
- Where
- 48 km (30 mi) east of Calipatria, CA · earthquakes near Calipatria
- Magnitude
- M 1.6 (ml)
- Depth
- -0.2 km below the surface
- Felt
- no reports yet
- Nearest
- Imperial County, 33 km W
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3031 days ago
Earthquake alerts for Calipatria, CA
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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 11 km (7 mi) from the epicentre. In Calipatria, 48 km away, the estimate is intensity I (not felt). 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.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 7.8 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.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 120× the energy of this one
- This earthquake M 1.6 about 7.8 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 6 earthquakes of M5 or more within 50 km; the five largest:
- 6.9 The 1940 Imperial Valley, California Earthquake · 44 km SW of this epicentre
- 5.5 Near Holtville, California · 42 km SW of this epicentre
- 5.3 8km E of Holtville, CA · 41 km SW of this epicentre
- 5.3 7km ESE of Calipatria, CA · 42 km W of this epicentre
- 5.3 6km ESE of Brawley, CA · 46 km WSW 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 33.0783, -115.0007. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Imperial County, CA | 33 km (21 mi) | W | earthquakes near Imperial County |
| Yuma County, AZ | 107 km (67 mi) | ESE | earthquakes near Yuma County |
| La Paz County, AZ | 115 km (71 mi) | NE | earthquakes near La Paz County |
| Riverside County, CA | 118 km (73 mi) | NW | earthquakes near Riverside County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
11 earthquakes have been recorded within 50 km since this one.
- 1.7 47km NE of Holtville, CA
- 1.7 45km NNW of Los Algodones, B.C., MX
- 1.6 46km NE of Holtville, CA
- 1.6 47km NE of Holtville, CA
- 1.7 44km NNW of Los Algodones, B.C., MX
- 2.0 45km NNW of Los Algodones, B.C., MX
- 1.7 47km NE of Holtville, CA
- 1.6 47km NE of Holtville, CA
- 1.6 44km NNW of Los Algodones, B.C., MX
- 1.7 45km NE of Holtville, CA
- 1.6 47km NE of Holtville, 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.