QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near Blue Lake, CA

No earthquake was likely felt in Blue Lake in the 24 hours to 4:21 am PST (12:21 UTC). The last one was M 5.0, 145 km (90 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 Blue Lake

This page: a magnitude 2.8 earthquake was recorded 20 km (13 mi) southeast of Blue Lake, CA, at 4:04 am PST on 20 December 2022 (12:04 UTC), 20 km deep. 7 people have reported feeling it to USGS.

USGS: 20km SE of Blue Lake, CA

4:04 am PST, Dec 20, 2022 · · 20 km deep · released about 490 lb of TNT

Every earthquake near Blue Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 8 kmTrinity County 62 kmDel Norte County 113 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
4:04 am PST on 20 December 2022 ()
Where
20 km (13 mi) southeast of Blue Lake, CA · earthquakes near Blue Lake
Magnitude
M 2.8 (md)
Depth
20 km below the surface
Felt
7 reports · strongest reported intensity III
Nearest
Humboldt County, 8 km WSW
Nearest mapped fault
Bald Mountain-Big Lagoon fault, 3 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 1353 days ago

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 20 km (12 mi) from the epicentre. In Blue Lake, 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.

Earthquakes near other towns within 30 km: Bayside, Arcata, Myrtletown, Cutten, Pine Hills, Eureka.

How big was it?

This earthquake released about 490 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 31,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.9× the energy of this one
  4. This earthquake M 2.8 about 490 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 4.9 on 2022-12-20 — about 1,500 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 The 1932 Eureka, California Earthquake · 38 km W of this epicentre
  2. 6.4 The 1954 Eureka-Arcata, California Earthquake · 13 km NNW of this epicentre
  3. 6.0 Near Rio Dell, California · 40 km SW of this epicentre
  4. 5.8 Near Eureka, California · 15 km WNW of this epicentre
  5. 5.6 15 km SW of Burnt Ranch, California · 19 km E 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 40.7355, -123.8405. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 8 km (5 mi) WSW earthquakes near Humboldt County
Trinity County, CA 62 km (39 mi) E earthquakes near Trinity County
Del Norte County, CA 113 km (70 mi) N earthquakes near Del Norte County
Siskiyou County, CA 145 km (90 mi) NE earthquakes near Siskiyou County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

56 earthquakes have been recorded within 50 km since this one.

  1. 2.7 7km WSW of Ferndale, CA
  2. 3.2 10km WSW of Ferndale, CA
  3. 2.3 9km SW of Ferndale, CA
  4. 2.1 5km SE of Ferndale, CA
  5. 2.5 6km NNE of Hydesville, CA
  6. 2.3 5km N of Hydesville, CA
  7. 2.2 21km NE of Hydesville, CA
  8. 2.4 10km NE of Hydesville, CA
  9. 2.1 10km WSW of Ferndale, CA
  10. 2.0 10km ENE of Hydesville, CA
  11. 2.4 8km SW of Ferndale, CA
  12. 1.8 6km SSW of Ferndale, CA
  13. 3.2 6km SW of Ferndale, CA
  14. 2.9 13km NE of Hydesville, CA
  15. 2.6 14 km ESE of Pine Hills, California

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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.