QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Earthquake near Susanville, CA

No earthquake was likely felt in Susanville in the 24 hours to 4:10 pm PST (00:10 UTC). The last one was M 2.2, 15 km (9 mi) N, at 8:16 am PDT on 25 September 2026, estimated intensity II (weak) in town. Every earthquake near Susanville

This page: a magnitude 2.5 earthquake was recorded 48 km (30 mi) north-northwest of Susanville, CA, at 6:03 pm PDT on 4 July 2021 (01:03 UTC), 14 km deep.

USGS: 48km NNW of Susanville, CA

6:03 pm PDT, Jul 4, 2021 · · 14 km deep · released about 160 lb of TNT

10 km30 km60 km120 km N Lassen County 24 kmModoc County 88 kmPlumas County 91 kmShasta County 98 kmWashoe County 103 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
6:03 pm PDT on 4 July 2021 ()
Where
48 km (30 mi) north-northwest of Susanville, CA · earthquakes near Susanville
Magnitude
M 2.5 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Lassen County, 24 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1889 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 17 km (11 mi) from the epicentre. In Susanville, 48 km away, the estimate is intensity II (weak). 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 160 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.

  1. Mineral, Virginia 2011 M 5.8 95,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 68,000× the energy of this one
  3. Around the size people start to feel M 3.0 6× the energy of this one
  4. This earthquake M 2.5 about 160 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 one earthquake of M5 or more within 50 km:

  1. 5.0 26 km S of Likely, California · 41 km ENE 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 40.8138, -120.8762. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lassen County, CA 24 km (15 mi) ESE earthquakes near Lassen County
Modoc County, CA 88 km (54 mi) N earthquakes near Modoc County
Plumas County, CA 91 km (57 mi) S earthquakes near Plumas County
Shasta County, CA 98 km (61 mi) W earthquakes near Shasta County
Washoe County, NV 103 km (64 mi) E earthquakes near Washoe County
Tehama County, CA 138 km (86 mi) WSW earthquakes near Tehama County

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

Aftershocks so far

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

  1. 1.9 10 km NNE of Susanville, CA
  2. 2.7 10 km NNE of Susanville, CA
  3. 1.6 35 km SSE of Fall River Mills, CA
  4. 1.7 28 km E of Viola, CA
  5. 2.0 38 km SSE of Fall River Mills, CA
  6. 1.6 40 km SSE of Fall River Mills, CA
  7. 1.9 26 km SE of Fall River Mills, CA
  8. 1.9 25 km S of Nubieber, California
  9. 2.2 26 km ESE of Fall River Mills, CA
  10. 2.1 8 km SE of McArthur, CA
  11. 1.6 22 km NNE of Chester, CA
  12. 1.8 37 km N of Chester, CA
  13. 2.0 37km SE of Fall River Mills, CA
  14. 2.4 47km NNW of Susanville, CA
  15. 2.3 26km SE of Fall River Mills, 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

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