QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Upper Lake, CA

No earthquake was likely felt in Upper Lake in the 24 hours to 8:53 pm PST (04:53 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 1.7 earthquake was recorded 21 km (13 mi) north of Upper Lake, CA, at 11:52 am PDT on 20 October 2016 (18:52 UTC), 6.8 km deep.

USGS: 20 km N of Upper Lake, California

11:52 am PDT, Oct 20, 2016 · · 6.8 km deep · released about 9.6 lb of TNT

Every earthquake near Upper Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 29 kmGlenn County 49 kmMendocino County 50 kmColusa County 58 kmSonoma County 92 kmTehama County 102 kmNapa County 105 kmSutter County 106 kmYolo County 112 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
11:52 am PDT on 20 October 2016 ()
Where
21 km (13 mi) north of Upper Lake, CA · earthquakes near Upper Lake
Magnitude
M 1.7 (md)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
Lake County, 29 km SSE
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 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 10 km (6 mi) from the epicentre. In Upper Lake, 21 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 9.6 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 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 · 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 39.3498, -122.8695. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 29 km (18 mi) SSE earthquakes near Lake County
Glenn County, CA 49 km (30 mi) NE earthquakes near Glenn County
Mendocino County, CA 50 km (31 mi) W earthquakes near Mendocino County
Colusa County, CA 58 km (36 mi) ESE earthquakes near Colusa County
Sonoma County, CA 92 km (57 mi) S earthquakes near Sonoma County
Tehama County, CA 102 km (63 mi) NNE earthquakes near Tehama County

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

Aftershocks so far

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

  1. 1.6 17 km ENE of Potter Valley, California
  2. 1.6 4 km NNE of Ukiah, California
  3. 1.5 23 km NNE of Upper Lake, California
  4. 2.4 19 km N of Upper Lake, California
  5. 3.0 20 km NNE of Upper Lake, California
  6. 1.6 20 km NNE of Upper Lake, California
  7. 1.8 18 km NNE of Upper Lake, California
  8. 1.8 21 km NNE of Upper Lake, California
  9. 1.6 20 km NNE of Upper Lake, California
  10. 1.6 17 km NNE of Upper Lake, California
  11. 2.1 19 km NNE of Upper Lake, California
  12. 2.0 Northern California
  13. 1.6 4 km ENE of Hopland, California
  14. 2.2 20 km NNE of Upper Lake, California
  15. 1.6 28 km WSW of Paskenta, 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.