QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Clearlake, CA

No earthquake was likely felt in Clearlake in the 24 hours to 5:20 am PST (13:20 UTC). The last one was M 2.6, 22 km (14 mi) SSW, at 4:44 pm PST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Clearlake

This page: a magnitude 1.6 earthquake was recorded 9 km (5 mi) east-northeast of Clearlake, CA, at 5:02 pm PDT on 15 April 2021 (00:02 UTC), less than 1 km deep.

USGS: 9km ENE of Clearlake, CA

5:02 pm PDT, Apr 15, 2021 · · -0.6 km deep · released about 7.3 lb of TNT

10 km30 km60 km120 km N Lake County 24 kmColusa County 34 kmNapa County 55 kmSonoma County 61 kmYolo County 63 kmGlenn County 71 kmSutter County 71 kmSolano County 94 kmMendocino County 94 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
5:02 pm PDT on 15 April 2021 ()
Where
9 km (5 mi) east-northeast of Clearlake, CA · earthquakes near Clearlake
Magnitude
M 1.6 (md)
Depth
-0.6 km below the surface
Felt
no reports yet
Nearest
Lake County, 24 km NW
Nearest mapped fault
Hunting Creek-Berryessa fault system, 2 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 2036 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 11 km (7 mi) from the epicentre. In Clearlake, 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.

Likely felt in: Clearlake 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 7.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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 180,000 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 38.9750, -122.5275. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 24 km (15 mi) NW earthquakes near Lake County
Colusa County, CA 34 km (21 mi) NE earthquakes near Colusa County
Napa County, CA 55 km (34 mi) SSE earthquakes near Napa County
Sonoma County, CA 61 km (38 mi) SW earthquakes near Sonoma County
Yolo County, CA 63 km (39 mi) ESE earthquakes near Yolo County
Glenn County, CA 71 km (44 mi) N earthquakes near Glenn County

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

Aftershocks so far

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

  1. 2.1 10km NW of The Geysers, CA
  2. 1.7 1km NW of The Geysers, CA
  3. 1.6 3km WNW of Lower Lake, CA
  4. 1.6 2km ESE of The Geysers, CA
  5. 2.8 5km NW of The Geysers, CA
  6. 1.6 5km NW of The Geysers, CA
  7. 1.6 6km NW of The Geysers, CA
  8. 2.7 4km NW of The Geysers, CA
  9. 1.8 10km WNW of The Geysers, CA
  10. 1.6 8km SE of Cloverdale, CA
  11. 1.5 10km ENE of Clearlake, CA
  12. 1.8 7km WNW of The Geysers, CA
  13. 2.0 5km NNW of The Geysers, CA
  14. 1.6 6km NW of The Geysers, CA
  15. 3.1 2km SSW of Anderson Springs, 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.