Earthquake · reviewed by a seismologist
M 2.9md
Earthquake near Hayfork, CA
No earthquake was likely felt in Hayfork in the 24 hours to 8:29 pm PST (04:29 UTC). The last one was M 3.7, 42 km (26 mi) W, at 2:44 pm PDT on 7 September 2026, estimated intensity II (weak) in town; 15 felt reports to USGS. Every earthquake near Hayfork
This page: a magnitude 2.9 earthquake was recorded 32 km (20 mi) south-southwest of Hayfork, CA, at 8:02 pm PDT on 6 July 2020 (03:02 UTC), 33 km deep.
USGS: 32km SSW of Hayfork, CA
- When
- 8:02 pm PDT on 6 July 2020 ()
- Where
- 32 km (20 mi) south-southwest of Hayfork, CA · earthquakes near Hayfork
- Magnitude
- M 2.9 (md)
- Depth
- 33 km below the surface
- Felt
- no reports yet
- Nearest
- Trinity County, 44 km NNE
- Nearest mapped fault
- Bartlett Springs fault system, 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 2252 days ago
Earthquake alerts for Hayfork, CA
Get a notification in this browser when USGS records an earthquake near Hayfork, CA. No account or email needed.
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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. In Hayfork, 32 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 780 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
- Magna, Utah 2020 M 5.7 14,000× the energy of this one
- Around the size people start to feel M 3.0 1.2× the energy of this one
- This earthquake M 2.9 about 780 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 4.5 on 2016-08-28 — about 210 times the energy of this one.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
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 40.2972, -123.3637. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Trinity County, CA | 44 km (28 mi) | NNE | earthquakes near Trinity County |
| Humboldt County, CA | 66 km (41 mi) | NW | earthquakes near Humboldt County |
| Mendocino County, CA | 96 km (60 mi) | S | earthquakes near Mendocino County |
| Tehama County, CA | 98 km (61 mi) | E | earthquakes near Tehama County |
| Glenn County, CA | 113 km (70 mi) | SE | earthquakes near Glenn County |
| Shasta County, CA | 123 km (76 mi) | ENE | earthquakes near Shasta County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
47 earthquakes have been recorded within 50 km since this one.
- 2.0 3km SE of Redway, CA
- 2.1 28km ENE of Redway, CA
- 2.1 23km NNE of Redway, CA
- 3.7 30km NNE of Redway, CA
- 1.8 6km ESE of Redway, CA
- 2.4 8km WNW of Hayfork, CA
- 1.6 19km NE of Covelo, CA
- 2.2 12km WNW of Covelo, CA
- 2.7 12km WNW of Covelo, CA
- 2.1 34km NE of Redway, CA
- 2.3 29km W of Hayfork, CA
- 1.7 12km NW of Covelo, CA
- 1.7 12km WNW of Covelo, CA
- 1.5 13km NW of Covelo, CA
- 1.6 13km NW of Covelo, 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.