QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

Earthquake near Covelo, CA

No earthquake was likely felt in Covelo in the 24 hours to 4:21 am PST (12:21 UTC). The last one was M 2.2, 9 km (6 mi) N, at 3:31 pm PST on 10 November 2026, estimated intensity II (weak) in town. Every earthquake near Covelo

This page: a magnitude 3.1 earthquake was recorded 12 km (8 mi) northwest of Covelo, CA, at 8:36 am PDT on 14 September 2020 (15:36 UTC), 6.5 km deep. 3 people have reported feeling it to USGS.

USGS: 12km NW of Covelo, CA

8:36 am PDT, Sep 14, 2020 · · 6.5 km deep · released about 1,200 lb of TNT

10 km30 km60 km120 km N Mendocino County 48 kmGlenn County 87 kmTrinity County 90 kmLake County 99 kmTehama County 101 kmHumboldt County 106 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
8:36 am PDT on 14 September 2020 ()
Where
12 km (8 mi) northwest of Covelo, CA · earthquakes near Covelo
Magnitude
M 3.1 (ml)
Depth
6.5 km below the surface
Felt
3 reports · strongest reported intensity II
Nearest
Mendocino County, 48 km S
Nearest mapped fault
Bartlett Springs fault system, under 1 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 2182 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 39 km (24 mi) from the epicentre. In Covelo, 12 km away, the estimate is intensity III (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.

Likely felt in: Covelo 12 km, intensity III · Laytonville 21 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 290,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 13,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 9,100× the energy of this one
  4. This earthquake M 3.1 about 1,200 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.2× more

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 2017-12-14 — about 63 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 · 33 km WSW 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 39.8583, -123.3663. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 48 km (30 mi) S earthquakes near Mendocino County
Glenn County, CA 87 km (54 mi) ESE earthquakes near Glenn County
Trinity County, CA 90 km (56 mi) NNE earthquakes near Trinity County
Lake County, CA 99 km (62 mi) SSE earthquakes near Lake County
Tehama County, CA 101 km (63 mi) ENE earthquakes near Tehama County
Humboldt County, CA 106 km (66 mi) NNW earthquakes near Humboldt 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.

  1. 1.6 2km N of Redway, CA
  2. 1.8 24km NW of Covelo, CA
  3. 1.6 10km NNE of Brooktrails, CA
  4. 1.7 8km WSW of Covelo, CA
  5. 2.0 7km NE of Willits, CA
  6. 1.9 12km SE of Laytonville, CA
  7. 2.1 6km E of Covelo, CA
  8. 1.6 20km NNE of Rockport, CA
  9. 2.3 41km NE of Covelo, CA
  10. 1.5 8km SSE of Laytonville, CA
  11. 1.6 8km SSE of Laytonville, CA
  12. 1.9 37km NE of Covelo, CA
  13. 1.7 13km N of Laytonville, CA
  14. 2.3 9km SSE of Laytonville, CA
  15. 2.0 3km SE 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

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