Earthquake · reviewed by a seismologist
M 2.5md
Earthquake near Hayfork, CA
No earthquake was likely felt in Hayfork in the 24 hours to 12:37 pm PST (20:37 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 2.5 earthquake was recorded 25 km (16 mi) west-northwest of Hayfork, CA, at 1:07 am PDT on 5 October 2017 (08:07 UTC), 22 km deep.
USGS: 1 km W of Hyampom, California
- When
- 1:07 am PDT on 5 October 2017 ()
- Where
- 25 km (16 mi) west-northwest of Hayfork, CA · earthquakes near Hayfork
- Magnitude
- M 2.5 (md)
- Depth
- 22 km below the surface
- Felt
- no reports yet
- Nearest
- Trinity County, 30 km E
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3326 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 7 km (4 mi) from the epicentre. In Hayfork, 25 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 180 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.
- Mineral, Virginia 2011 M 5.8 83,000× the energy of this one
- Magna, Utah 2020 M 5.7 59,000× the energy of this one
- Around the size people start to feel M 3.0 5.2× the energy of this one
- This earthquake M 2.5 about 180 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 4.8 on 2016-07-21 — about 2,700 times the energy of this one.
Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:
- 6.4 The 1954 Eureka-Arcata, California Earthquake · 44 km NW of this epicentre
- 5.8 Near Eureka, California · 49 km WNW of this epicentre
- 5.6 15 km SW of Burnt Ranch, California · 16 km NW of this epicentre
- 5.4 3 km NNW of Burnt Ranch, California · 24 km N 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 40.6168, -123.4720. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Trinity County, CA | 30 km (19 mi) | E | earthquakes near Trinity County |
| Humboldt County, CA | 40 km (25 mi) | WNW | earthquakes near Humboldt County |
| Tehama County, CA | 118 km (74 mi) | ESE | earthquakes near Tehama County |
| Siskiyou County, CA | 134 km (83 mi) | NE | earthquakes near Siskiyou County |
| Glenn County, CA | 145 km (90 mi) | SE | earthquakes near Glenn 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.
- 2.1 34km ENE of Redway, CA
- 2.3 28km W of Hayfork, CA
- 2.4 28km W of Hayfork, CA
- 1.6 29km NNE of Redway, CA
- 1.8 15km SE of Blue Lake, CA
- 1.7 30km NNE of Redway, CA
- 2.1 19km NNE of Redway, CA
- 2.7 14km ESE of Willow Creek, CA
- 2.0 37km NNE of Redway, CA
- 2.5 38km NNE of Redway, CA
- 1.9 9km NNW of Hayfork, CA
- 3.0 8km NNW of Hayfork, CA
- 2.4 16km S of Willow Creek, CA
- 1.8 16km S of Willow Creek, CA
- 1.8 6km N of Hayfork, 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.