QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Clearlake Oaks, CA

No earthquake was likely felt in Clearlake Oaks in the 24 hours to 10:33 am PST (18:33 UTC). The last one was M 2.8, 19 km (12 mi) SE, at 1:02 pm PST on 2 November 2026, estimated intensity II (weak) in town. Every earthquake near Clearlake Oaks

This page: a magnitude 1.8 earthquake was recorded 8 km (5 mi) east of Clearlake Oaks, CA, at 4:14 pm PDT on 19 April 2018 (23:14 UTC), less than 1 km deep.

USGS: 8km E of Clearlake Oaks, CA

4:14 pm PDT, Apr 19, 2018 · · -0.1 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Lake County 17 kmColusa County 33 kmNapa County 62 kmSonoma County 64 kmGlenn County 66 kmYolo County 70 kmSutter County 75 kmMendocino County 87 kmSolano County 101 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
4:14 pm PDT on 19 April 2018 ()
Where
8 km (5 mi) east of Clearlake Oaks, CA · earthquakes near Clearlake Oaks
Magnitude
M 1.8 (md)
Depth
-0.1 km below the surface
Felt
no reports yet
Nearest
Lake County, 17 km WNW
Nearest mapped fault
Bartlett Springs fault system, 3 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 3128 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 14 km (9 mi) from the epicentre. In Clearlake Oaks, 8 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 16 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 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 80,000 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.2 6 km ESE of Talmage, California · 46 km WNW 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 39.0280, -122.5740. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 17 km (11 mi) WNW earthquakes near Lake County
Colusa County, CA 33 km (21 mi) ENE earthquakes near Colusa County
Napa County, CA 62 km (38 mi) SSE earthquakes near Napa County
Sonoma County, CA 64 km (40 mi) SSW earthquakes near Sonoma County
Glenn County, CA 66 km (41 mi) NNE earthquakes near Glenn County
Yolo County, CA 70 km (43 mi) ESE earthquakes near Yolo County

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

Aftershocks so far

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

  1. 1.6 3km WNW of The Geysers, CA
  2. 1.8 7km WNW of The Geysers, CA
  3. 1.6 18km NE of Upper Lake, CA
  4. 1.7 7km NW of The Geysers, CA
  5. 2.0 7km NW of The Geysers, CA
  6. 2.0 7km NW of The Geysers, CA
  7. 1.8 6km WNW of The Geysers, CA
  8. 1.6 3km W of Cobb, CA
  9. 1.7 8km SE of Lake Pillsbury, CA
  10. 1.7 6km WNW of The Geysers, CA
  11. 1.8 6km WNW of Cobb, CA
  12. 1.5 6km NW of The Geysers, CA
  13. 2.6 6km WNW of Cobb, CA
  14. 2.8 7km WNW of The Geysers, CA
  15. 1.5 5km NNW 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.