Earthquake · reviewed by a seismologist
M 2.5md
Earthquake near Hayfork, CA
No earthquake was likely felt in Hayfork in the 24 hours to 11:35 pm PST (07:35 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 (15 mi) west of Hayfork, CA, at 6:41 pm PDT on 19 October 2018 (01:41 UTC), 23 km deep. 3 people have reported feeling it to USGS.
USGS: 25km W of Hayfork, CA
- When
- 6:41 pm PDT on 19 October 2018 ()
- Where
- 25 km (15 mi) west of Hayfork, CA · earthquakes near Hayfork
- Magnitude
- M 2.5 (md)
- Depth
- 23 km below the surface
- Felt
- 3 reports · strongest reported intensity II
- Nearest
- Trinity County, 33 km ENE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2943 days ago
Earthquake alerts for Hayfork, 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 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 3 km (2 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 200 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 75,000× the energy of this one
- Magna, Utah 2020 M 5.7 53,000× the energy of this one
- Around the size people start to feel M 3.0 4.7× the energy of this one
- This earthquake M 2.5 about 200 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 2,500 times the energy of this one.
Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:
- 6.4 The 1954 Eureka-Arcata, California Earthquake · 49 km NW of this epicentre
- 5.6 15 km SW of Burnt Ranch, California · 23 km NNW of this epicentre
- 5.4 3 km NNW of Burnt Ranch, California · 33 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 40.5388, -123.4770. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Trinity County, CA | 33 km (20 mi) | ENE | earthquakes near Trinity County |
| Humboldt County, CA | 42 km (26 mi) | WNW | earthquakes near Humboldt County |
| Tehama County, CA | 115 km (71 mi) | ESE | earthquakes near Tehama County |
| Glenn County, CA | 139 km (86 mi) | SE | earthquakes near Glenn County |
| Siskiyou County, CA | 141 km (88 mi) | NE | earthquakes near Siskiyou County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
48 earthquakes have been recorded within 50 km since this one.
- 1.8 17km ESE of Pine Hills, CA
- 1.5 28km NNE of Redway, CA
- 1.7 25km NNW of Redway, CA
- 1.8 31km ESE of Rio Dell, CA
- 1.7 8km E of Hydesville, CA
- 2.3 24km E of Hydesville, CA
- 3.8 16km ESE of Pine Hills, CA
- 2.5 7km ESE of Hydesville, CA
- 2.1 9km ENE of Hydesville, CA
- 2.9 22km NNW of Hayfork, CA
- 1.8 15km E of Hydesville, CA
- 2.0 31km W of Hayfork, CA
- 2.0 31km W of Hayfork, CA
- 2.0 20km SSE of Willow Creek, CA
- 2.0 34km NE of Redway, 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.