QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Susanville, CA

No earthquake was likely felt in Susanville in the 24 hours to 5:17 pm PST (01:17 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 1.8 earthquake was recorded 33 km (21 mi) north-northwest of Susanville, CA, at 11:17 am PDT on 12 May 2021 (18:17 UTC), 13 km deep.

USGS: 33km NNW of Susanville, CA

11:17 am PDT, May 12, 2021 · · 13 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Lassen County 16 kmPlumas County 77 kmWashoe County 97 kmModoc County 101 kmShasta County 104 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
11:17 am PDT on 12 May 2021 ()
Where
33 km (21 mi) north-northwest of Susanville, CA · earthquakes near Susanville
Magnitude
M 1.8 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Lassen County, 16 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2010 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 4 km (2 mi) from the epicentre. In Susanville, 33 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 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 · 46 km NE 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 40.6887, -120.8098. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lassen County, CA 16 km (10 mi) E earthquakes near Lassen County
Plumas County, CA 77 km (48 mi) S earthquakes near Plumas County
Washoe County, NV 97 km (60 mi) E earthquakes near Washoe County
Modoc County, CA 101 km (63 mi) N earthquakes near Modoc County
Shasta County, CA 104 km (65 mi) W earthquakes near Shasta County
Butte County, CA 132 km (82 mi) SSW earthquakes near Butte County

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

Aftershocks so far

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

  1. 1.8 37 km N of Chester, CA
  2. 1.8 4 km NNW of Hamilton Branch, CA
  3. 2.0 37km SE of Fall River Mills, CA
  4. 2.4 47km NNW of Susanville, CA
  5. 1.6 14km NNW of Chester, CA
  6. 2.0 5km NE of Hamilton Branch, CA
  7. 2.3 26km SE of Fall River Mills, CA
  8. 1.6 29 km NW of Susanville, California
  9. 1.8 36km SE of Fall River Mills, CA
  10. 1.9 23km ESE of McArthur, CA
  11. 2.5 48km NNW of Susanville, CA
  12. 1.6 25km NNE of Hamilton Branch, 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.