QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Clearlake, CA

No earthquake was likely felt in Clearlake in the 24 hours to 11:34 pm PST (07:34 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 1.5 earthquake was recorded 15 km (9 mi) east-northeast of Clearlake, CA, at 12:49 am PDT on 17 August 2023 (07:49 UTC), less than 1 km deep.

USGS: 15 km ENE of Clearlake, CA

12:49 am PDT, Aug 17, 2023 · · -0.5 km deep · released about 5.7 lb of TNT

10 km30 km60 km120 km N Lake County 27 kmColusa County 28 kmNapa County 56 kmYolo County 60 kmSutter County 66 kmSonoma County 66 kmGlenn County 68 kmSolano County 93 kmMendocino County 97 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
12:49 am PDT on 17 August 2023 ()
Where
15 km (9 mi) east-northeast of Clearlake, CA · earthquakes near Clearlake
Magnitude
M 1.5 (md)
Depth
-0.5 km below the surface
Felt
no reports yet
Nearest
Lake County, 27 km WNW
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 1182 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 Clearlake, 15 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: Lower Lake, Clearlake Oaks, Hidden Valley Lake, Clear Lake Riviera, Soda Bay, Cobb.

How big was it?

This earthquake released about 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 230,000 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 38.9950, -122.4630. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 27 km (17 mi) WNW earthquakes near Lake County
Colusa County, CA 28 km (17 mi) NE earthquakes near Colusa County
Napa County, CA 56 km (35 mi) SSE earthquakes near Napa County
Yolo County, CA 60 km (37 mi) SE earthquakes near Yolo County
Sutter County, CA 66 km (41 mi) E earthquakes near Sutter County
Sonoma County, CA 66 km (41 mi) SW earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 1.5 4 km W of Cobb, CA
  2. 1.7 14 km ESE of Lake Pillsbury, CA
  3. 1.7 1 km NE of The Geysers, CA
  4. 1.7 3 km NNW of The Geysers, CA
  5. 1.5 2 km W of Anderson Springs, CA
  6. 1.7 8 km WNW of Cobb, CA
  7. 1.6 3 km NE of The Geysers, CA
  8. 1.8 18 km SE of Lake Pillsbury, CA
  9. 2.5 18 km NNE of Upper Lake, CA
  10. 1.7 10 km WNW of The Geysers, CA
  11. 1.6 7 km WNW of Cobb, CA
  12. 1.6 2 km NW of The Geysers, CA
  13. 1.9 7 km NW of The Geysers, CA
  14. 1.6 1 km NE of The Geysers, CA
  15. 1.8 7 km WNW of The Geysers, 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.