QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Lakeport, CA

No earthquake was likely felt in Lakeport in the 24 hours to 3:41 am PST (11:41 UTC). The last one was M 4.0, 51 km (32 mi) N, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Lakeport

This page: a magnitude 1.7 earthquake was recorded 12 km (8 mi) west of Lakeport, CA, at 11:35 am PST on 12 February 2021 (19:35 UTC), 5.3 km deep.

USGS: 12km W of Lakeport, CA

11:35 am PST, Feb 12, 2021 · · 5.3 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N Lake County 28 kmMendocino County 55 kmSonoma County 58 kmColusa County 73 kmGlenn County 85 kmNapa County 86 kmYolo County 108 kmMarin County 113 kmSutter County 117 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
11:35 am PST on 12 February 2021 ()
Where
12 km (8 mi) west of Lakeport, CA · earthquakes near Lakeport
Magnitude
M 1.7 (md)
Depth
5.3 km below the surface
Felt
no reports yet
Nearest
Lake County, 28 km ENE
Nearest mapped fault
Maacama fault, 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 2098 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 Lakeport, 12 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: North Lakeport, Talmage, Ukiah, Upper Lake, Kelseyville, Nice.

How big was it?

This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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 130,000 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 · 10 km NNW 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 39.0335, -123.0582. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 28 km (18 mi) ENE earthquakes near Lake County
Mendocino County, CA 55 km (34 mi) NW earthquakes near Mendocino County
Sonoma County, CA 58 km (36 mi) SSE earthquakes near Sonoma County
Colusa County, CA 73 km (45 mi) ENE earthquakes near Colusa County
Glenn County, CA 85 km (53 mi) NE earthquakes near Glenn County
Napa County, CA 86 km (54 mi) SE earthquakes near Napa 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. 1.5 3km W of Cobb, CA
  2. 1.8 10km ESE of Willits, CA
  3. 1.6 6km NW of The Geysers, CA
  4. 1.5 20km SSW of Willits, CA
  5. 2.6 11km ESE of Willits, CA
  6. 1.5 2km E of The Geysers, CA
  7. 2.3 4km NW of The Geysers, CA
  8. 2.7 4km NNW of The Geysers, CA
  9. 1.6 4km NNW of The Geysers, CA
  10. 2.0 13km W of Lake Pillsbury, CA
  11. 1.7 5km NW of The Geysers, CA
  12. 1.8 5km SSW of Redwood Valley, CA
  13. 1.6 3km SSW of Cobb, CA
  14. 2.0 8km W of Cobb, CA
  15. 1.7 7km SW of Boonville, 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.