QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Redwood Valley, CA

No earthquake was likely felt in Redwood Valley in the 24 hours to 9:22 pm PST (05:22 UTC). The last one was M 1.5, 7 km (5 mi) SE, at 12:31 pm PST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Redwood Valley

This page: a magnitude 1.7 earthquake was recorded 11 km (7 mi) east-southeast of Redwood Valley, CA, at 6:00 pm PDT on 19 June 2021 (01:00 UTC), 6.9 km deep.

USGS: 11km ESE of Redwood Valley, CA

94 km (58 mi) NNW of Santa Rosa, CA

6:00 pm PDT, Jun 19, 2021 · · 6.9 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Lake County 32 kmMendocino County 38 kmGlenn County 71 kmColusa County 73 kmSonoma County 80 kmNapa County 104 kmYolo County 119 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
6:00 pm PDT on 19 June 2021 ()
Where
11 km (7 mi) east-southeast of Redwood Valley, CA · earthquakes near Redwood Valley
Magnitude
M 1.7 (md)
Depth
6.9 km below the surface
Felt
no reports yet
Nearest
Lake County, 32 km ESE
Nearest mapped fault
Maacama fault, 11 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 1972 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 11 km (7 mi) from the epicentre. In Redwood Valley, 11 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: Talmage, Ukiah, Upper Lake, North Lakeport, Nice, Lakeport.

How big was it?

This earthquake released about 12 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 110,000 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 · 13 km S 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 39.2360, -123.0803. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 32 km (20 mi) ESE earthquakes near Lake County
Mendocino County, CA 38 km (24 mi) NW earthquakes near Mendocino County
Glenn County, CA 71 km (44 mi) NE earthquakes near Glenn County
Colusa County, CA 73 km (45 mi) E earthquakes near Colusa County
Sonoma County, CA 80 km (50 mi) S earthquakes near Sonoma County
Napa County, CA 104 km (65 mi) SE earthquakes near Napa County

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

Aftershocks so far

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

  1. 2.3 6km E of Willits, CA
  2. 1.6 13km SE of Talmage, CA
  3. 1.9 14km SSW of Lake Pillsbury, CA
  4. 1.7 10km WNW of The Geysers, CA
  5. 1.7 4km NW of Redwood Valley, CA
  6. 1.6 7km ENE of Brooktrails, CA
  7. 1.8 6km ESE of Clearlake Oaks, CA
  8. 2.4 9km WNW of Cobb, CA
  9. 1.5 16km SSW of Willits, CA
  10. 1.8 13km W of Lakeport, CA
  11. 1.7 17km NNE of Nice, CA
  12. 2.1 7km E of Clearlake Oaks, CA
  13. 2.7 9km NW of The Geysers, CA
  14. 1.5 8km ESE of Willits, CA
  15. 2.0 15km WNW of Lake Pillsbury, 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.