Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Susanville, CA
No earthquake was likely felt in Susanville in the 24 hours to 11:19 am PST (19:19 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 1.7 earthquake was recorded 9 km (6 mi) north-northwest of Susanville, CA, at 4:45 pm PDT on 20 August 2020 (23:45 UTC), 2.9 km deep.
USGS: 9km NNW of Susanville, CA
- When
- 4:45 pm PDT on 20 August 2020 ()
- Where
- 9 km (6 mi) north-northwest of Susanville, CA · earthquakes near Susanville
- Magnitude
- M 1.7 (md)
- Depth
- 2.9 km below the surface
- Felt
- no reports yet
- Nearest
- Lassen County, 26 km NNE
- Nearest mapped fault
- Honey Lake fault, 9 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 2276 days ago
Earthquake alerts for Susanville, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 12 km (7 mi) from the epicentre. In Susanville, 9 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.
Likely felt in: Susanville 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
- Around the size people start to feel M 3.0 92× the energy of this one
- This earthquake M 1.7 about 10 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:
- 5.7 2 km NNE of Canyondam, California · 45 km SW 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 40.4920, -120.6975. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lassen County, CA | 26 km (16 mi) | NNE | earthquakes near Lassen County |
| Plumas County, CA | 57 km (35 mi) | S | earthquakes near Plumas County |
| Washoe County, NV | 91 km (57 mi) | ENE | earthquakes near Washoe County |
| Sierra County, CA | 103 km (64 mi) | S | earthquakes near Sierra County |
| Shasta County, CA | 117 km (73 mi) | WNW | earthquakes near Shasta County |
| Butte County, CA | 120 km (75 mi) | SW | earthquakes near Butte County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
50 earthquakes have been recorded within 50 km since this one.
- 2.0 3km SSW of East Shore, CA
- 2.0 5km NE of Hamilton Branch, CA
- 2.1 3km SW of East Shore, CA
- 1.5 4km NNE of Prattville, CA
- 1.6 4km ESE of Chester, CA
- 2.1 4km NNW of Canyondam, CA
- 1.8 5km E of Chester, CA
- 1.7 4km ESE of Chester, CA
- 2.5 3km E of Prattville, CA
- 2.3 3km ENE of Prattville, CA
- 1.6 29 km NW of Susanville, California
- 1.6 2km E of Prattville, CA
- 2.8 2km ENE of Prattville, CA
- 2.5 2km ENE of Prattville, CA
- 2.8 2km NE of Almanor, 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.