Earthquake · reviewed by a seismologist
M 2.3md
Earthquake near Hamilton City, CA
USGS: 16km S of Hamilton City, CA
25 km (15 mi) SW of Chico, CA · 124 km (77 mi) NNW of Sacramento, CA
- When
- 3:23 pm PST on 26 February 2018 ()
- Where
- 16 km (10 mi) S of Hamilton City, CA · earthquakes near Hamilton City
- Magnitude
- M 2.3 (md)
- Depth
- 24 km below the surface
- Felt
- 1 report · strongest reported intensity III
- Nearest
- Glenn County, 33 km W
- Nearest mapped fault
- Great Valley thrust fault system, 24 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3140 days ago
A magnitude 2.3 earthquake was recorded 16 km (10 mi) S of Hamilton City, CA, at 3:23 pm PST on 26 February 2018 (23:23 UTC). 1 person has reported feeling it to USGS. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
Earthquakes near other towns within 30 km: Willows, Durham, Chico, Orland.
How big was it?
This earthquake released about 79 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 190,000× the energy of this one
- Magna, Utah 2020 M 5.7 130,000× the energy of this one
- Around the size people start to feel M 3.0 12× the energy of this one
- This earthquake M 2.3 about 79 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 3 earthquakes of M5 or more within 50 km:
- 5.7 The 1975 Oroville, California Earthquake · 45 km ESE of this epicentre
- 5.2 4 km E of Palermo, California · 49 km ESE of this epicentre
- 5.1 5 km ENE of Palermo, California · 49 km ESE 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 39.6010, -122.0178. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Glenn County, CA | 33 km (20 mi) | W | earthquakes near Glenn County |
| Butte County, CA | 36 km (23 mi) | ENE | earthquakes near Butte County |
| Colusa County, CA | 51 km (32 mi) | SSW | earthquakes near Colusa County |
| Tehama County, CA | 61 km (38 mi) | NNW | earthquakes near Tehama County |
| Sutter County, CA | 68 km (42 mi) | SSE | earthquakes near Sutter County |
| Yuba County, CA | 69 km (43 mi) | ESE | earthquakes near Yuba County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 2.5 5km NNE of Hamilton City, CA
- 2.5 4km SE of Concow, CA
- 1.9 10km N of Oroville, CA
- 1.9 10km SSE of Hamilton City, CA
- 2.0 5km NNE of Hamilton City, CA
- 2.0 5km NNE of Hamilton City, CA
- 2.0 5km NNE of Hamilton City, CA
- 3.0 1km NNW of Chico, CA
- 2.8 4km NE of Hamilton City, CA
- 1.8 4km NE of Hamilton City, CA
- 2.9 4km NE of Hamilton City, CA
- 1.9 6km N of Chico, CA
- 1.9 4km ENE of Palermo, CA
- 2.5 8km W of Durham, CA
- 1.6 15km SW of Durham, 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.