Earthquake · reviewed by a seismologist
M 2.3md
Earthquake near Redway, CA
No earthquake was likely felt in Redway in the 24 hours to 9:50 pm PST (05:50 UTC). The last one was M 5.0, 153 km (95 mi) WNW, at 8:56 pm PST on 4 November 2026, estimated intensity II (weak) in town; 145 felt reports to USGS. Every earthquake near Redway
This page: a magnitude 2.3 earthquake was recorded 20 km (12 mi) north-northeast of Redway, CA, at 2:33 pm PST on 20 December 2021 (22:33 UTC), 26 km deep. 3 people have reported feeling it to USGS.
USGS: 20km NNE of Redway, CA
- When
- 2:33 pm PST on 20 December 2021 ()
- Where
- 20 km (12 mi) north-northeast of Redway, CA · earthquakes near Redway
- Magnitude
- M 2.3 (md)
- Depth
- 26 km below the surface
- Felt
- 3 reports · strongest reported intensity III
- Nearest
- Humboldt County, 48 km NNW
- Nearest mapped fault
- Little Salmon fault, 20 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 1784 days ago
Earthquake alerts for Redway, CA
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Alerts are on for .
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This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. In Redway, 20 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 91 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 170,000× the energy of this one
- Magna, Utah 2020 M 5.7 120,000× the energy of this one
- Around the size people start to feel M 3.0 10× the energy of this one
- This earthquake M 2.3 about 91 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 6.2 on 2021-12-20 — about 660,000 times the energy of this one.
Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:
- 7.2 The 1992 Petrolia, California Earthquake · 39 km W of this epicentre
- 6.0 Near Rio Dell, California · 43 km WNW of this epicentre
- 6.0 31 km NW of Shelter Cove, California · 48 km W of this epicentre
- 6.0 30 km SSW of Scotia, California · 44 km W of this epicentre
- 5.6 15 km SW of Burnt Ranch, California · 48 km NNE 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 40.2945, -123.7672. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Humboldt County, CA | 48 km (30 mi) | NNW | earthquakes near Humboldt County |
| Trinity County, CA | 68 km (42 mi) | NE | earthquakes near Trinity County |
| Mendocino County, CA | 100 km (62 mi) | SSE | earthquakes near Mendocino County |
| Glenn County, CA | 140 km (87 mi) | ESE | earthquakes near Glenn County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
54 earthquakes have been recorded within 50 km since this one.
- 1.8 11km NNE of Petrolia, CA
- 2.6 6km N of Petrolia, CA
- 2.4 7km N of Petrolia, CA
- 2.7 2km NE of Petrolia, CA
- 2.8 13km S of Ferndale, CA
- 1.7 13km WSW of Rio Dell, CA
- 1.7 13km N of Petrolia, CA
- 2.0 8km NNE of Petrolia, CA
- 1.6 7km N of Petrolia, CA
- 1.7 4km ENE of Petrolia, CA
- 2.9 12km N of Petrolia, CA
- 2.5 5km N of Petrolia, CA
- 2.1 9km NNE of Petrolia, CA
- 3.9 6km N of Petrolia, CA
- 2.7 14km S of Ferndale, 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.