QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Clear Lake Riviera, CA

No earthquake was likely felt in Clear Lake Riviera in the 24 hours to 11:16 pm PST (07:16 UTC). The last one was M 2.6, 19 km (12 mi) S, at 4:44 pm PST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Clear Lake Riviera

This page: a magnitude 1.9 earthquake was recorded 3 km (2 mi) west of Clear Lake Riviera, CA, at 5:19 pm PDT on 25 September 2017 (00:19 UTC), 4.2 km deep. 2 people have reported feeling it to USGS.

USGS: 3 km W of Clear Lake Riviera, California

57 km (35 mi) N of Santa Rosa, CA · 134 km (83 mi) NNW of San Francisco, CA

5:19 pm PDT, Sep 25, 2017 · · 4.2 km deep · released about 25 lb of TNT

Every earthquake near Clear Lake Riviera Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 17 kmSonoma County 50 kmColusa County 51 kmNapa County 62 kmGlenn County 78 kmMendocino County 79 kmYolo County 80 kmSutter County 92 kmMarin County 101 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
5:19 pm PDT on 25 September 2017 ()
Where
3 km (2 mi) west of Clear Lake Riviera, CA · earthquakes near Clear Lake Riviera
Magnitude
M 1.9 (md)
Depth
4.2 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Lake County, 17 km N
Nearest mapped fault
Konocti Bay fault, 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 1558 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 Clear Lake Riviera, 3 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.

Likely felt in: Clearlake 12 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 53,000 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 · 34 km WNW 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 38.9557, -122.7597. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 17 km (11 mi) N earthquakes near Lake County
Sonoma County, CA 50 km (31 mi) SSW earthquakes near Sonoma County
Colusa County, CA 51 km (32 mi) ENE earthquakes near Colusa County
Napa County, CA 62 km (39 mi) SE earthquakes near Napa County
Glenn County, CA 78 km (49 mi) NNE earthquakes near Glenn County
Mendocino County, CA 79 km (49 mi) NW earthquakes near Mendocino 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. 2.5 5 km S of Cobb, California
  2. 2.0 5 km S of Cobb, California
  3. 2.4 18 km NE of Upper Lake, California
  4. 1.6 Northern California
  5. 2.7 5 km SSW of Cobb, California
  6. 1.6 Northern California
  7. 1.8 9 km W of Hopland, California
  8. 1.9 8 km W of Cobb, California
  9. 1.6 11 km ESE of Hidden Valley Lake, California
  10. 1.9 8 km W of Cobb, California
  11. 1.7 5 km SSE of Cobb, California
  12. 1.6 8 km W of Cobb, California
  13. 2.3 4 km SW of Cobb, California
  14. 1.6 8 km WSW of Cobb, California
  15. 2.5 8 km WSW of Cobb, 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.