Earthquake · reviewed by a seismologist
M 4.4mw
1km SE of Delta, B.C., MX
Yes. A magnitude 4.4 earthquake was recorded 1km SE of Delta, B.C., MX, 65 km (40 mi) WSW of Yuma, AZ, at 7:17 pm MST on 28 September 2018 (02:17 UTC), 29 km deep. 101 people have reported feeling it to USGS.
65 km (40 mi) WSW of Yuma, AZ
- When
- Magnitude
- M 4.4 (mw)
- Depth
- 29 km below the surface
- Felt
- 101 reports · strongest reported intensity III
- Measured shaking
- intensity VI (ShakeMap)
- USGS impact alert
- green
- Tsunami
- USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
- Nearest
- Imperial County, 79 km NNW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2903 days ago
Earthquake alerts for San Luis, AZ
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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 light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.
At this magnitude and depth, people at rest would likely notice it out to about 128 km (80 mi) from the epicentre. 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: Calexico 47 km, intensity III. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 62 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.4 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 2,700× the energy of this one
- Mineral, Virginia 2011 M 5.8 120× the energy of this one
- Magna, Utah 2020 M 5.7 86× the energy of this one
- This earthquake M 4.4 about 62 tons of TNT
- Around the size people start to feel M 3.0 this one released 130× more
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.
Where
Epicentre 32.3477, -115.1840. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Imperial County, CA | 79 km (49 mi) | NNW | earthquakes near Imperial County |
| Yuma County, AZ | 128 km (80 mi) | ENE | earthquakes near Yuma County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
49 earthquakes have been recorded within 50 km since this one.
- 1.8 5km S of Mexicali, B.C., MX
- 2.3 3km N of Guadalupe Victoria, B.C., MX
- 2.9 18km S of Alberto Oviedo Mota, B.C., MX
- 2.4 7km W of Alberto Oviedo Mota, B.C., MX
- 2.1 10km W of Alberto Oviedo Mota, B.C., MX
- 2.4 8km W of Alberto Oviedo Mota, B.C., MX
- 2.4 4km WSW of Alberto Oviedo Mota, B.C., MX
- 2.5 6km W of Alberto Oviedo Mota, B.C., MX
- 1.7 10km S of Progreso, B.C., MX
- 2.5 6km W of Alberto Oviedo Mota, B.C., MX
- 2.5 7km W of Alberto Oviedo Mota, B.C., MX
- 2.8 6km W of Alberto Oviedo Mota, B.C., MX
- 1.6 11km S of Progreso, B.C., MX
- 2.4 8km WSW of Alberto Oviedo Mota, B.C., MX
- 2.6 10km S of Progreso, B.C., MX
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.