QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Covelo, CA

No earthquake was likely felt in Covelo in the 24 hours to 2:36 am PST (10:36 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 1.8 earthquake was recorded 13 km (8 mi) northwest of Covelo, CA, at 10:49 pm PDT on 16 September 2020 (05:49 UTC), 6.7 km deep.

USGS: 13km NW of Covelo, CA

10:49 pm PDT, Sep 16, 2020 · · 6.7 km deep · released about 17 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
10:49 pm PDT on 16 September 2020 ()
Where
13 km (8 mi) northwest of Covelo, CA · earthquakes near Covelo
Magnitude
M 1.8 (md)
Depth
6.7 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 48 km S
Nearest mapped fault
Bartlett Springs fault system, 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 2240 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 12 km (7 mi) from the epicentre. In Covelo, 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.

Likely felt in: Covelo 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 2017-12-14 — about 4,300 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 · 32 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 39.8577, -123.3695. 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

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

  1. 1.6 11km SE of Laytonville, CA
  2. 1.8 12km SE of Laytonville, CA
  3. 2.3 12km NNW of Covelo, CA
  4. 3.0 20km NNE of Rockport, CA
  5. 2.1 20km NNE of Rockport, CA
  6. 1.8 4km N of Laytonville, CA
  7. 1.6 14km SSE of Covelo, CA
  8. 1.6 8km WSW of Covelo, CA
  9. 1.7 12km WNW of Covelo, CA
  10. 1.6 2km N of Redway, CA
  11. 1.8 24km NW of Covelo, CA
  12. 1.6 10km NNE of Brooktrails, CA
  13. 1.7 8km WSW of Covelo, CA
  14. 2.0 7km NE of Willits, CA
  15. 1.9 12km SE of Laytonville, 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.