QuakeIndex

Earthquake · reviewed by a seismologist

M 5.1mw

Earthquake near Upper Lake, CA

No earthquake was likely felt in Upper Lake in the 24 hours to 7:31 am PST (15:31 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 5.1 earthquake was recorded 21 km (13 mi) north-northeast of Upper Lake, CA, at 7:57 pm PDT on 9 August 2016 (02:57 UTC), 14 km deep. 960 people have reported feeling it to USGS.

USGS: 20 km NNE of Upper Lake, California

7:57 pm PDT, Aug 9, 2016 · · 14 km deep · released about 650 tons of TNT

Every earthquake near Upper Lake Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 25 kmGlenn County 46 kmColusa County 51 kmMendocino County 56 kmSonoma County 90 kmSutter County 100 kmNapa County 100 kmTehama County 101 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
7:57 pm PDT on 9 August 2016 ()
Where
21 km (13 mi) north-northeast of Upper Lake, CA · earthquakes near Upper Lake
Magnitude
M 5.1 (mw)
Depth
14 km below the surface
Felt
960 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Lake County, 25 km S
Nearest mapped fault
Bartlett Springs fault system, 4 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 302 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

At this magnitude and depth, people at rest would likely notice it out to about 204 km (127 mi) from the epicentre. In Upper Lake, 21 km away, the estimate is intensity IV (light). 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.

Likely felt in: Upper Lake 21 km, intensity IV · Lakeport 33 km, intensity IV · Ukiah 40 km, intensity IV · Clearlake 44 km, intensity IV · Willits 48 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 650 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 260× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12× the energy of this one
  3. Magna, Utah 2020 M 5.7 8.2× the energy of this one
  4. This earthquake M 5.1 about 650 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 1,400× more

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 (31 mi) since our catalogue begins in 2016. No other earthquake of M4 or more has been recorded this close in that time.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.2 6 km ESE of Talmage, California · 35 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 39.3293, -122.8018. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 25 km (16 mi) S earthquakes near Lake County
Glenn County, CA 46 km (28 mi) NE earthquakes near Glenn County
Colusa County, CA 51 km (32 mi) ESE earthquakes near Colusa County
Mendocino County, CA 56 km (35 mi) WNW earthquakes near Mendocino County
Sonoma County, CA 90 km (56 mi) S earthquakes near Sonoma County
Sutter County, CA 100 km (62 mi) ESE 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. 1.8 21 km NNE of Upper Lake, California
  2. 2.1 19 km NNE of Upper Lake, California
  3. 1.8 21 km NNE of Upper Lake, California
  4. 1.7 3 km ENE of Willits, California
  5. 1.8 20 km NNE of Upper Lake, California
  6. 1.7 19 km NNE of Upper Lake, California
  7. 1.8 21 km NNE of Upper Lake, California
  8. 1.8 20 km NNE of Upper Lake, California
  9. 1.8 20 km NNE of Upper Lake, California
  10. 1.8 20 km NNE of Upper Lake, California
  11. 1.9 20 km WSW of Stonyford, California
  12. 1.6 21 km W of Stonyford, California
  13. 1.8 21 km NNE of Upper Lake, California
  14. 1.8 19 km NNE of Upper Lake, California
  15. 1.9 20 km WSW of Stonyford, 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.