QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Upper Lake, CA

No earthquake was likely felt in Upper Lake in the 24 hours to 9:45 am PST (17:45 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 2.1 earthquake was recorded 18 km (11 mi) north-northeast of Upper Lake, CA, at 11:40 am PDT on 12 September 2016 (18:40 UTC), 9.2 km deep. 2 people have reported feeling it to USGS.

USGS: 18 km NNE of Upper Lake, California

11:40 am PDT, Sep 12, 2016 · · 9.2 km deep · released about 46 lb of TNT

Every earthquake near Upper Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 24 kmGlenn County 48 kmColusa County 52 kmMendocino County 55 kmSonoma County 88 kmNapa County 99 kmSutter County 101 kmTehama County 103 kmYolo County 106 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
11:40 am PDT on 12 September 2016 ()
Where
18 km (11 mi) north-northeast of Upper Lake, CA · earthquakes near Upper Lake
Magnitude
M 2.1 (md)
Depth
9.2 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Lake County, 24 km SSE
Nearest mapped fault
Bartlett Springs 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 3561 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 15 km (9 mi) from the epicentre. In Upper Lake, 18 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.

How big was it?

This earthquake released about 46 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 330,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 21× the energy of this one
  4. This earthquake M 2.1 about 46 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 29,000 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 · 33 km SW 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 39.3140, -122.8162. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 24 km (15 mi) SSE earthquakes near Lake County
Glenn County, CA 48 km (30 mi) NE earthquakes near Glenn County
Colusa County, CA 52 km (32 mi) ESE earthquakes near Colusa County
Mendocino County, CA 55 km (34 mi) WNW earthquakes near Mendocino County
Sonoma County, CA 88 km (55 mi) S earthquakes near Sonoma County
Napa County, CA 99 km (62 mi) SSE earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.9 20 km NNE of Upper Lake, California
  2. 1.8 19 km NNE of Upper Lake, California
  3. 1.7 8 km NE of Boonville, California
  4. 2.8 20 km NNE of Upper Lake, California
  5. 1.7 9 km NNE of Hopland, California
  6. 2.0 Northern California
  7. 1.5 20 km NNE of Upper Lake, California
  8. 1.8 17 km NE of Willits, California
  9. 1.5 18 km NE of Upper Lake, California
  10. 2.1 6 km N of Hopland, California
  11. 1.6 19 km NNE of Upper Lake, California
  12. 1.5 20 km NNE of Upper Lake, California
  13. 1.6 21 km E of Potter Valley, California
  14. 1.8 10 km SSW of Kelseyville, California
  15. 1.7 18 km NE of Upper Lake, California

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.