QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Upper Lake, CA

No earthquake was likely felt in Upper Lake in the 24 hours to 10:23 am PST (18:23 UTC). The last one was M 1.6, 8 km (5 mi) W, at 4:31 am PST on 10 November 2026, estimated intensity II (weak) in town. Every earthquake near Upper Lake

This page: a magnitude 1.8 earthquake was recorded 15 km (10 mi) northeast of Upper Lake, CA, at 2:58 pm PDT on 21 May 2022 (21:58 UTC), less than 1 km deep.

USGS: 16km NE of Upper Lake, CA

2:58 pm PDT, May 21, 2022 · · -0.7 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Lake County 17 kmColusa County 48 kmGlenn County 50 kmMendocino County 60 kmSonoma County 83 kmNapa County 93 kmSutter County 96 kmYolo County 100 kmTehama County 107 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
2:58 pm PDT on 21 May 2022 ()
Where
15 km (10 mi) northeast of Upper Lake, CA · earthquakes near Upper Lake
Magnitude
M 1.8 (md)
Depth
-0.7 km below the surface
Felt
no reports yet
Nearest
Lake County, 17 km S
Nearest mapped fault
Bartlett Springs fault system, 1 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 1635 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 13 km (8 mi) from the epicentre. In Upper Lake, 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: Nice, North Lakeport, Lakeport, Clearlake Oaks, Soda Bay.

How big was it?

This earthquake released about 13 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 99,000 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 · 32 km WSW 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 39.2603, -122.7805. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 17 km (11 mi) S earthquakes near Lake County
Colusa County, CA 48 km (30 mi) E earthquakes near Colusa County
Glenn County, CA 50 km (31 mi) NE earthquakes near Glenn County
Mendocino County, CA 60 km (37 mi) WNW earthquakes near Mendocino County
Sonoma County, CA 83 km (51 mi) S earthquakes near Sonoma County
Napa County, CA 93 km (58 mi) SSE earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.7 6km ESE of Lake Pillsbury, CA
  2. 1.5 3km WNW of Cobb, CA
  3. 1.7 4km E of Willits, CA
  4. 1.8 6km ESE of Lake Pillsbury, CA
  5. 1.6 2km NW of Cobb, CA
  6. 1.6 3km NNW of Cobb, CA
  7. 1.7 3km NW of Cobb, CA
  8. 2.1 2km NW of Cobb, CA
  9. 4.2 2km WNW of Cobb, CA
  10. 1.6 15km NW of Lake Pillsbury, CA
  11. 1.6 5km ENE of Talmage, CA
  12. 1.5 8km NW of The Geysers, CA
  13. 1.6 6km NW of The Geysers, CA
  14. 1.7 6km NW of The Geysers, CA
  15. 1.8 10km SE of Willits, 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.