Earthquake · reviewed by a seismologist
M 4.5mw
22km W of Petrolia, CA
- When
- Magnitude
- M 4.5 (mw)
- Depth
- 15 km below the surface
- Felt
- 196 reports · strongest reported intensity IV
- Measured shaking
- intensity III (ShakeMap)
- USGS impact alert
- green
- Tsunami
- USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
- Nearest
- Humboldt County, 70 km NE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3033 days ago
This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 196 people have reported feeling it to USGS.
How big was it?
This earthquake released about 79 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.5 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 2,100× the energy of this one
- Mineral, Virginia 2011 M 5.8 95× the energy of this one
- Magna, Utah 2020 M 5.7 68× the energy of this one
- This earthquake M 4.5 about 79 tons of TNT
- Around the size people start to feel M 3.0 this one released 170× 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 40.2918, -124.5423. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Humboldt County, CA | 70 km (43 mi) | SW of here | earthquakes near Humboldt County |
| Mendocino County, CA | 134 km (83 mi) | NW of here | earthquakes near Mendocino County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
58 earthquakes have been recorded within 50 km since this one.
- 1.7 10km WSW of Petrolia, CA
- 2.8 35km W of Petrolia, CA
- 2.1 6km SW of Petrolia, CA
- 2.4 9km SW of Petrolia, CA
- 2.2 20km W of Petrolia, CA
- 2.5 34km WNW of Petrolia, CA
- 2.8 59km WNW of Petrolia, CA
- 2.4 21km W of Petrolia, CA
- 1.7 21km NW of Petrolia, CA
- 2.6 65km W of Ferndale, CA
- 2.7 35km WNW of Ferndale, CA
- 2.6 35km WNW of Ferndale, CA
- 1.9 12km NW of Petrolia, CA
- 2.5 8km NNW of Petrolia, CA
- 2.5 9km NNW of Petrolia, 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.
For this area
The largest earthquake within 50 km in our catalogue was M 4.4 on 2016-01-02.
From the QuakeIndex catalogue, built from the USGS FDSN event service.
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.