QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Middletown, CA

No earthquake was likely felt in Middletown in the 24 hours to 11:17 pm PST (07:17 UTC). The last one was M 1.6, 9 km (6 mi) WNW, at 5:12 am PST on 10 November 2026, estimated intensity II (weak) in town. Every earthquake near Middletown

This page: a magnitude 1.7 earthquake was recorded in Middletown, CA, at 5:07 am PST on 20 November 2016 (13:07 UTC), 5.2 km deep.

USGS: 1 km NW of Middletown, California

36 km (22 mi) N of Santa Rosa, CA · 111 km (69 mi) N of San Francisco, CA

5:07 am PST, Nov 20, 2016 · · 5.2 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N Sonoma County 37 kmNapa County 39 kmLake County 40 kmColusa County 57 kmYolo County 63 kmMarin County 80 kmSolano County 81 kmSutter County 85 kmGlenn County 95 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
5:07 am PST on 20 November 2016 ()
Where
in Middletown, CA · earthquakes near Middletown
Magnitude
M 1.7 (md)
Depth
5.2 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 37 km SW
Nearest mapped fault
Konocti Bay fault, 10 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 11 km (7 mi) from the epicentre. 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: Cobb 11 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 10 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 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 38.7637, -122.6267. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 37 km (23 mi) SW earthquakes near Sonoma County
Napa County, CA 39 km (24 mi) SE earthquakes near Napa County
Lake County, CA 40 km (25 mi) NNW earthquakes near Lake County
Colusa County, CA 57 km (35 mi) NE earthquakes near Colusa County
Yolo County, CA 63 km (39 mi) E earthquakes near Yolo County
Marin County, CA 80 km (50 mi) S earthquakes near Marin County

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

Aftershocks so far

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

  1. 1.8 2 km SSW of Cobb, California
  2. 2.6 3 km W of Cobb, California
  3. 1.9 7 km W of Cobb, California
  4. 2.3 7 km W of Cobb, California
  5. 1.8 6 km W of Middletown, California
  6. 2.3 10 km W of Cobb, California
  7. 2.0 7 km W of Cobb, California
  8. 1.9 7 km W of Cobb, California
  9. 1.6 2 km SSW of Cobb, California
  10. 1.8 9 km W of Cobb, California
  11. 1.5 6 km SSW of Cobb, California
  12. 1.5 6 km W of Cobb, California
  13. 1.7 9 km WNW of Cobb, California
  14. 1.6 3 km SSW of Cobb, California
  15. 2.2 3 km SSW 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.