Earthquake · reviewed by a seismologist
M 2.1md
6km WSW of Petrolia, CA
- When
- Magnitude
- M 2.1 (md)
- Depth
- 7.8 km below the surface
- Felt
- no reports yet
- Nearest
- Humboldt County, 58 km NE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2425 days ago
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
How big was it?
This earthquake released about 51 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 300,000× the energy of this one
- Magna, Utah 2020 M 5.7 210,000× the energy of this one
- Around the size people start to feel M 3.0 19× the energy of this one
- This earthquake M 2.1 about 51 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.
Where
Epicentre 40.2980, -124.3480. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Humboldt County, CA | 58 km (36 mi) | SW of here | earthquakes near Humboldt County |
| Trinity County, CA | 111 km (69 mi) | WSW of here | earthquakes near Trinity County |
| Mendocino County, CA | 123 km (77 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
57 earthquakes have been recorded within 50 km since this one.
- 1.9 13km WSW of Petrolia, CA
- 1.8 10km N of Petrolia, CA
- 2.2 13km WNW of Petrolia, CA
- 1.7 7km NE of Petrolia, CA
- 1.8 12km SSE of Rio Dell, CA
- 2.3 36km WNW of Petrolia, CA
- 1.9 22km WSW of Ferndale, CA
- 2.4 34km W of Petrolia, CA
- 1.9 11km W of Petrolia, CA
- 2.2 42km WNW of Petrolia, CA
- 1.7 23km NW of Petrolia, CA
- 1.5 10km SSW of Rio Dell, CA
- 1.7 12km NW of Petrolia, CA
- 2.3 14km WNW of Petrolia, CA
- 5.2 15km W 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 5.6 on 2019-06-23 — it released about 140,000 times the energy of this one.
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.