QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Laytonville, CA

No earthquake was likely felt in Laytonville in the 24 hours to 1:35 am PST (09:35 UTC). The last one was M 2.4, 13 km (8 mi) WSW, at 7:25 am PST on 4 November 2026, estimated intensity II (weak) in town. Every earthquake near Laytonville

This page: a magnitude 1.7 earthquake was recorded 13 km (8 mi) southeast of Laytonville, CA, at 2:17 am PST on 30 December 2021 (10:17 UTC), 7.5 km deep.

USGS: 13km SE of Laytonville, CA

2:17 am PST, Dec 30, 2021 · · 7.5 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Mendocino County 19 kmLake County 77 kmGlenn County 84 kmColusa County 109 kmTehama County 115 kmTrinity County 119 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
2:17 am PST on 30 December 2021 ()
Where
13 km (8 mi) southeast of Laytonville, CA · earthquakes near Laytonville
Magnitude
M 1.7 (md)
Depth
7.5 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 19 km SSW
Nearest mapped fault
Maacama fault, 6 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 1774 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In Laytonville, 13 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: Brooktrails, Willits, Covelo.

How big was it?

This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× the energy of this one
  4. This earthquake M 1.7 about 12 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 4.3 on 2019-04-29 — about 7,700 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.9 9 km S of Leggett, California · 36 km NW 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 39.5973, -123.3855. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 19 km (12 mi) SSW earthquakes near Mendocino County
Lake County, CA 77 km (48 mi) SE earthquakes near Lake County
Glenn County, CA 84 km (52 mi) E earthquakes near Glenn County
Colusa County, CA 109 km (68 mi) ESE earthquakes near Colusa County
Tehama County, CA 115 km (71 mi) ENE earthquakes near Tehama County
Trinity County, CA 119 km (74 mi) N earthquakes near Trinity County

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

Aftershocks so far

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

  1. 1.9 18km SW of Willits, CA
  2. 1.9 13km WNW of Alder Springs, CA
  3. 1.8 14km NE of Willits, CA
  4. 1.9 20km NE of Brooktrails, CA
  5. 1.7 6km E of Willits, CA
  6. 2.2 20km NE of Covelo, CA
  7. 2.1 5km E of Covelo, CA
  8. 1.7 9km W of Covelo, CA
  9. 1.9 6km E of Covelo, CA
  10. 1.9 2km W of Redwood Valley, CA
  11. 1.6 7km ESE of Redwood Valley, CA
  12. 1.8 5km NW of Lake Pillsbury, CA
  13. 2.0 23km NW of Alder Springs, CA
  14. 2.3 5km E of Covelo, CA
  15. 1.7 5km E of Covelo, 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.