Earthquake · reviewed by a seismologist
M 2.1md
Earthquake near Magalia, CA
USGS: 6 km S of Stirling City, California
27 km (17 mi) ENE of Chico, CA
- When
- 1:56 pm PDT on 9 August 2017 ()
- Where
- 7 km (4 mi) NE of Magalia, CA · earthquakes near Magalia
- Magnitude
- M 2.1 (md)
- Depth
- 3.8 km below the surface
- Felt
- 1 report · strongest reported intensity III
- Nearest
- Butte County, 22 km SSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3334 days ago
A magnitude 2.1 earthquake was recorded 7 km (4 mi) NE of Magalia, CA, at 1:56 pm PDT on 9 August 2017 (20:56 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: Forest Ranch, Paradise, Berry Creek.
How big was it?
This earthquake released about 46 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 5.8 330,000× the energy of this one
- Magna, Utah 2020 M 5.7 230,000× the energy of this one
- Around the size people start to feel M 3.0 21× the energy of this one
- This earthquake M 2.1 about 46 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 · 47 km S of this epicentre
- 5.2 4 km E of Palermo, California · 46 km S of this epicentre
- 5.1 5 km ENE of Palermo, California · 45 km S 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 39.8520, -121.5205. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Butte County, CA | 22 km (14 mi) | SSW | earthquakes near Butte County |
| Plumas County, CA | 61 km (38 mi) | ENE | earthquakes near Plumas County |
| Yuba County, CA | 66 km (41 mi) | SSE | earthquakes near Yuba County |
| Tehama County, CA | 68 km (42 mi) | WNW | earthquakes near Tehama County |
| Glenn County, CA | 80 km (50 mi) | WSW | earthquakes near Glenn County |
| Nevada County, CA | 89 km (55 mi) | SE | earthquakes near Nevada County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
32 earthquakes have been recorded within 50 km since this one.
- 1.6 6km W of Almanor, CA
- 1.5 15km SW of Chester, CA
- 1.8 12km S of Hamilton City, CA
- 1.7 3 km S of Canyondam, California
- 2.2 4km S of Canyondam, CA
- 2.0 10km NNW of Oroville, CA
- 1.6 10km SSE of Hamilton City, CA
- 1.6 4 km S of Canyondam, California
- 1.7 1 km NW of Paxton, California
- 1.9 10km N of Oroville, CA
- 2.0 2km NW of Paxton, CA
- 2.1 13km SE of Mineral, CA
- 2.0 10km N of Thermalito, CA
- 1.9 11km WNW of Belden, CA
- 1.6 11km WSW of Chester, 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.