QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

44 km E of Fort Bidwell, California

Yes. A magnitude 1.6 earthquake was recorded 44 km E of Fort Bidwell, California, at 9:40 pm PST on 4 December 2025 (05:40 UTC), 6.7 km deep.

· 6.7 km deep · released about 7.3 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Modoc County 95 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 1.6 (ml)
Depth
6.7 km below the surface
Felt
no reports yet
Nearest
Modoc County, 95 km WSW
Nearest mapped fault
Warner Valley faults, 4 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 330 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 7.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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

The largest earthquake within 50 km since 2016 was M 4.1 on 2016-01-03 — about 5,800 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.0 25 km SSE of Plush, Oregon · 42 km NNW 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 41.8473, -119.6204. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Modoc County, CA 95 km (59 mi) WSW earthquakes near Modoc County
Lake County, OR 122 km (76 mi) NNW earthquakes near Lake County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

28 earthquakes have been recorded within 50 km since this one.

  1. 2.4 39 km E of Fort Bidwell, California
  2. 2.2 47 km ESE of Plush, Oregon
  3. 2.1 54 km ENE of Fort Bidwell, California
  4. 2.0 45 km E of Fort Bidwell, California
  5. 1.8 46 km ENE of Fort Bidwell, California
  6. 1.6 48 km E of Fort Bidwell, California
  7. 1.8 46 km E of Fort Bidwell, California
  8. 2.2 48 km SE of Plush, Oregon
  9. 1.7 46 km ENE of Fort Bidwell, California
  10. 1.9 47 km E of Fort Bidwell, California
  11. 1.7 45 km E of Fort Bidwell, California
  12. 1.7 47 km E of Fort Bidwell, California
  13. 2.0 40 km E of Fort Bidwell, California
  14. 1.9 47 km E of Fort Bidwell, California
  15. 2.1 46 km E of Fort Bidwell, California

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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.