QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Earthquake near Willow Creek, CA

No earthquake was likely felt in Willow Creek in the 24 hours to 11:41 pm PST (07:41 UTC). The last one was M 5.0, 175 km (109 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 Willow Creek

This page: a magnitude 2.5 earthquake was recorded 9 km (5 mi) east of Willow Creek, CA, at 8:03 am PDT on 2 November 2021 (15:03 UTC), 26 km deep.

USGS: 8km E of Willow Creek, CA

8:03 am PDT, Nov 2, 2021 · · 26 km deep · released about 140 lb of TNT

Every earthquake near Willow Creek Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 42 kmTrinity County 48 kmDel Norte County 97 kmSiskiyou County 110 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
8:03 am PDT on 2 November 2021 ()
Where
9 km (5 mi) east of Willow Creek, CA · earthquakes near Willow Creek
Magnitude
M 2.5 (md)
Depth
26 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 42 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1763 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Willow Creek, 9 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 140 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.

  1. Mineral, Virginia 2011 M 5.8 110,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 75,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.7× the energy of this one
  4. This earthquake M 2.5 about 140 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 3,500 times the energy of this one.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1954 Eureka-Arcata, California Earthquake · 32 km WSW of this epicentre
  2. 5.8 Near Eureka, California · 43 km WSW of this epicentre
  3. 5.6 15 km SW of Burnt Ranch, California · 26 km SSW of this epicentre
  4. 5.6 26 km NNW of Willow Creek, California · 31 km NW of this epicentre
  5. 5.4 3 km NNW of Burnt Ranch, California · 12 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 40.9413, -123.5297. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 42 km (26 mi) SW earthquakes near Humboldt County
Trinity County, CA 48 km (30 mi) SE earthquakes near Trinity County
Del Norte County, CA 97 km (61 mi) NNW earthquakes near Del Norte County
Siskiyou County, CA 110 km (68 mi) NE earthquakes near Siskiyou County
Tehama County, CA 142 km (88 mi) SE earthquakes near Tehama 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.

  1. 2.1 36km W of Hayfork, CA
  2. 2.5 24km SE of Blue Lake, CA
  3. 2.1 28km WNW of Hayfork, CA
  4. 2.3 15km E of Willow Creek, CA
  5. 1.9 18km ENE of Hydesville, CA
  6. 2.4 17km ENE of Willow Creek, CA
  7. 1.8 20km SSE of Willow Creek, CA
  8. 2.1 25km WNW of Weaverville, CA
  9. 2.0 7km W of Willow Creek, CA
  10. 2.4 14km E of Willow Creek, CA
  11. 2.3 28km ENE of Willow Creek, CA
  12. 1.7 31km W of Hayfork, CA
  13. 2.1 26km ESE of Willow Creek, CA
  14. 2.4 7km S of Somes Bar, CA
  15. 2.3 14km SE of Bayside, 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

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