QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Monument Hills, CA

No earthquake was likely felt in Monument Hills in the 24 hours to 11:23 pm PST (07:23 UTC). The last one was M 4.2, 93 km (58 mi) W, at 7:40 pm PDT on 28 July 2026, estimated intensity II (weak) in town; 240 felt reports to USGS. Every earthquake near Monument Hills

This page: a magnitude 2.1 earthquake was recorded 7 km (4 mi) south-southwest of Monument Hills, CA, at 5:55 am PST on 22 November 2016 (13:55 UTC), 12 km deep.

USGS: 6 km SSW of Monument Hills, California

15 km (9 mi) WNW of Davis, CA · 37 km (23 mi) W of Sacramento, CA

5:55 am PST, Nov 22, 2016 · · 12 km deep · released about 37 lb of TNT

10 km30 km60 km120 km N Yolo County 8 kmSolano County 38 kmNapa County 39 kmSacramento County 51 kmSutter County 51 kmColusa County 70 kmContra Costa County 76 kmYuba County 88 kmSonoma County 90 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
5:55 am PST on 22 November 2016 ()
Where
7 km (4 mi) south-southwest of Monument Hills, CA · earthquakes near Monument Hills
Magnitude
M 2.1 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Yolo County, 8 km N
Nearest mapped fault
Great Valley thrust fault system, 12 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 12 km (7 mi) from the epicentre. In Monument Hills, 7 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: Monument Hills 7 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 37 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 lists one earthquake of M5 or more within 50 km:

  1. 5.4 South of Elmira, California · 34 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 38.6037, -121.8947. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Yolo County, CA 8 km (5 mi) N earthquakes near Yolo County
Solano County, CA 38 km (23 mi) S earthquakes near Solano County
Napa County, CA 39 km (24 mi) WSW earthquakes near Napa County
Sacramento County, CA 51 km (32 mi) ESE earthquakes near Sacramento County
Sutter County, CA 51 km (32 mi) NNE earthquakes near Sutter County
Colusa County, CA 70 km (44 mi) NNW earthquakes near Colusa 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. 1.8 7 km ENE of Napa, California
  2. 2.8 15 km WSW of Esparto, California
  3. 1.7 13 km NNW of Moskowite Corner, California
  4. 3.3 2 km ENE of Angwin, California
  5. 1.9 14 km NW of Moskowite Corner, California
  6. 1.7 6 km SSW of Nicolaus, California
  7. 1.8 6 km WSW of Dunnigan, California
  8. 2.0 4 km SSE of Monument Hills, California
  9. 2.4 5 km SSW of Dunnigan, California
  10. 1.6 Northern California
  11. 1.8 8 km SSW of Dunnigan, California
  12. 1.7 7 km SSW of Dunnigan, California
  13. 2.0 6 km SW of Dunnigan, California
  14. 2.5 6 km SW of Dunnigan, California
  15. 1.6 10 km W of Esparto, 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.