Earthquake · reviewed by a seismologist
M 2.9md
Earthquake near Arcata, CA
No earthquake was likely felt in Arcata in the 24 hours to 5:36 am PST (13:36 UTC). The last one was M 5.0, 137 km (85 mi) WSW, at 8:56 pm PST on 4 November 2026, estimated intensity II (weak) in town; 145 felt reports to USGS. Every earthquake near Arcata
This page: a magnitude 2.9 earthquake was recorded 47 km (29 mi) northeast of Arcata, CA, at 1:31 am PST on 11 January 2020 (09:31 UTC), 31 km deep. 1 person has reported feeling it to USGS.
USGS: 11km SE of Weitchpec, CA
- When
- 1:31 am PST on 11 January 2020 ()
- Where
- 47 km (29 mi) northeast of Arcata, CA · earthquakes near Arcata
- Magnitude
- M 2.9 (md)
- Depth
- 31 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Humboldt County, 52 km SSW
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2415 days ago
Earthquake alerts for Arcata, CA
Get a notification in this browser when USGS records an earthquake near Arcata, 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 10 km (6 mi) from the epicentre. In Arcata, 47 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.
Earthquakes near other towns within 30 km: Willow Creek.
How big was it?
This earthquake released about 700 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 22,000× the energy of this one
- Magna, Utah 2020 M 5.7 15,000× the energy of this one
- Around the size people start to feel M 3.0 1.4× the energy of this one
- This earthquake M 2.9 about 700 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 710 times the energy of this one.
Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:
- 6.4 The 1954 Eureka-Arcata, California Earthquake · 37 km SW of this epicentre
- 5.8 Near Eureka, California · 47 km SW of this epicentre
- 5.6 15 km SW of Burnt Ranch, California · 44 km S of this epicentre
- 5.6 26 km NNW of Willow Creek, California · 15 km WNW of this epicentre
- 5.4 3 km NNW of Burnt Ranch, California · 32 km SSE 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 41.1097, -123.6197. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Humboldt County, CA | 52 km (32 mi) | SSW | earthquakes near Humboldt County |
| Trinity County, CA | 67 km (41 mi) | SE | earthquakes near Trinity County |
| Del Norte County, CA | 77 km (48 mi) | NNW | earthquakes near Del Norte County |
| Siskiyou County, CA | 105 km (65 mi) | ENE | earthquakes near Siskiyou County |
| Tehama County, CA | 160 km (100 mi) | SE | earthquakes near Tehama County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 2.4 11km WSW of Willow Creek, CA
- 2.6 5km SW of Somes Bar, CA
- 2.2 24km NW of Hayfork, CA
- 2.8 7km W of Weitchpec, CA
- 2.9 29km ENE of Willow Creek, CA
- 2.3 10km SE of Willow Creek, CA
- 1.8 11km SSE of Blue Lake, CA
- 2.2 9km ESE of Willow Creek, CA
- 2.4 21km SSE of Willow Creek, CA
- 2.5 16km SSE of Somes Bar, CA
- 2.5 8km E of Willow Creek, CA
- 2.0 18km ESE of Willow Creek, CA
- 2.3 20km ENE of Willow Creek, CA
- 2.3 18km E of Willow Creek, CA
- 2.4 12km SE of Weitchpec, 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.