QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Hidden Valley Lake, CA

No earthquake was likely felt in Hidden Valley Lake in the 24 hours to 11:05 pm PST (07:05 UTC). The last one was M 2.6, 18 km (11 mi) W, at 4:44 pm PST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Hidden Valley Lake

This page: a magnitude 1.6 earthquake was recorded 9 km (6 mi) east-northeast of Hidden Valley Lake, CA, at 4:12 pm PST on 21 January 2018 (00:12 UTC), 7.0 km deep.

USGS: 9km ENE of Hidden Valley Lake, CA

48 km (30 mi) NNE of Santa Rosa, CA · 118 km (73 mi) N of San Francisco, CA

4:12 pm PST, Jan 21, 2018 · · 7.0 km deep · released about 9 lb of TNT

10 km30 km60 km120 km N Napa County 39 kmLake County 39 kmColusa County 43 kmYolo County 52 kmSonoma County 53 kmSutter County 69 kmSolano County 78 kmGlenn County 85 kmMarin County 91 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
4:12 pm PST on 21 January 2018 ()
Where
9 km (6 mi) east-northeast of Hidden Valley Lake, CA · earthquakes near Hidden Valley Lake
Magnitude
M 1.6 (md)
Depth
7.0 km below the surface
Felt
no reports yet
Nearest
Napa County, 39 km SSE
Nearest mapped fault
Hunting Creek-Berryessa fault system, 7 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 3214 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 9 km (6 mi) from the epicentre. In Hidden Valley Lake, 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.

Earthquakes near other towns within 30 km: Lower Lake, Middletown, Clearlake, Cobb, Clear Lake Riviera, Clearlake Oaks.

How big was it?

This earthquake released about 9 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 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 9 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 5.0 on 2016-12-14 — about 110,000 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 38.8375, -122.4617. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 39 km (24 mi) SSE earthquakes near Napa County
Lake County, CA 39 km (24 mi) NW earthquakes near Lake County
Colusa County, CA 43 km (26 mi) NNE earthquakes near Colusa County
Yolo County, CA 52 km (32 mi) ESE earthquakes near Yolo County
Sonoma County, CA 53 km (33 mi) SW earthquakes near Sonoma County
Sutter County, CA 69 km (43 mi) ENE earthquakes near Sutter County

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

Aftershocks so far

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

  1. 1.7 10km WNW of Cobb, CA
  2. 2.7 10km WNW of Cobb, CA
  3. 2.2 6km NW of The Geysers, CA
  4. 1.6 7km E of Clearlake Oaks, CA
  5. 1.7 10km NNE of Cloverdale, CA
  6. 2.1 4km W of Cobb, CA
  7. 1.9 6km NW of The Geysers, CA
  8. 2.5 10km NNE of Cloverdale, CA
  9. 1.6 6km W of Cobb, CA
  10. 1.6 3km SSW of Anderson Springs, CA
  11. 1.8 2km NNW of The Geysers, CA
  12. 1.8 10km WNW of The Geysers, CA
  13. 2.4 10km WNW of The Geysers, CA
  14. 1.5 7km WNW of The Geysers, CA
  15. 1.9 2km SE 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.