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 3:32 am PST (11:32 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 22 km (14 mi) southeast of Covelo, CA, at 1:54 pm PST on 13 March 2021 (21:54 UTC), 5.1 km deep.

USGS: 22km SE of Covelo, CA

1:54 pm PST, Mar 13, 2021 · · 5.1 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Mendocino County 37 kmGlenn County 60 kmLake County 65 kmColusa County 89 kmTehama County 92 kmTrinity 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
1:54 pm PST on 13 March 2021 ()
Where
22 km (14 mi) southeast of Covelo, CA · earthquakes near Covelo
Magnitude
M 1.8 (md)
Depth
5.1 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 37 km SW
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 2067 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, 22 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 13 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 5.1 on 2016-08-10 — about 99,000 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 39.6297, -123.0975. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 37 km (23 mi) SW earthquakes near Mendocino County
Glenn County, CA 60 km (37 mi) E earthquakes near Glenn County
Lake County, CA 65 km (41 mi) SSE earthquakes near Lake County
Colusa County, CA 89 km (56 mi) SE earthquakes near Colusa County
Tehama County, CA 92 km (57 mi) NE earthquakes near Tehama County
Trinity County, CA 113 km (70 mi) N earthquakes near Trinity 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 7km E of Willits, CA
  2. 1.6 9km NNW of Redwood Valley, CA
  3. 1.7 8km NNW of Redwood Valley, CA
  4. 1.7 19km SW of Laytonville, CA
  5. 1.9 15km N of Brooktrails, CA
  6. 2.9 4km SSE of Redwood Valley, CA
  7. 2.0 12km WNW of Redwood Valley, CA
  8. 1.8 10km NNW of Redwood Valley, CA
  9. 1.5 2km WNW of Laytonville, CA
  10. 1.9 11km N of Covelo, CA
  11. 2.6 10km NNW of Redwood Valley, CA
  12. 1.9 8km NW of Laytonville, CA
  13. 2.0 5km WSW of Laytonville, CA
  14. 1.6 8km SSE of Laytonville, CA
  15. 1.9 13km SE of Lake Pillsbury, 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.