Earthquake · reviewed by a seismologist
M 2.5md
4km SW of Humboldt Hill, CA
- When
- Magnitude
- M 2.5 (md)
- Depth
- 18 km below the surface
- Felt
- 4 reports · strongest reported intensity II
- Nearest
- Humboldt County, 25 km E
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1183 days ago
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 4 people have reported feeling it to USGS.
How big was it?
This earthquake released about 190 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 78,000× the energy of this one
- Magna, Utah 2020 M 5.7 55,000× the energy of this one
- Around the size people start to feel M 3.0 4.9× the energy of this one
- This earthquake M 2.5 about 190 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 40.7005, -124.2178. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Humboldt County, CA | 25 km (15 mi) | W of here | earthquakes near Humboldt County |
| Trinity County, CA | 93 km (58 mi) | W of here | earthquakes near Trinity County |
| Del Norte County, CA | 118 km (74 mi) | S of here | earthquakes near Del Norte 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.
- 1.6 9km SW of Ferndale, CA
- 1.8 21km NW of Petrolia, CA
- 1.7 13km SSW of Ferndale, CA
- 1.9 14km WSW of Ferndale, CA
- 1.6 14km NW of Petrolia, CA
- 2.3 10km NW of Petrolia, CA
- 1.7 2km SSE of Fortuna, CA
- 1.9 4km WNW of Ferndale, CA
- 1.9 14km WSW of Ferndale, CA
- 2.6 25km WSW of Ferndale, CA
- 1.9 13km WSW of Ferndale, CA
- 1.9 20km WSW of Ferndale, CA
- 2.8 20km WSW of Ferndale, CA
- 2.3 19km WSW of Ferndale, CA
- 1.6 10km SSW of Ferndale, 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 6.4 on 2022-12-20 — it released about 620,000 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.