QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Hamilton City, CA

No earthquake was likely felt in Hamilton City in the 24 hours to 12:48 am PST (08:48 UTC). The last one was M 4.0, 85 km (53 mi) WSW, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Hamilton City

This page: a magnitude 2.1 earthquake was recorded 9 km (6 mi) south of Hamilton City, CA, at 2:50 pm PDT on 13 May 2017 (21:50 UTC), 22 km deep.

USGS: 8 km S of Hamilton City, California

21 km (13 mi) WSW of Chico, CA

2:50 pm PDT, May 13, 2017 · · 22 km deep · released about 44 lb of TNT

10 km30 km60 km120 km N Glenn County 33 kmButte County 36 kmTehama County 54 kmColusa County 57 kmYuba County 73 kmSutter County 75 kmLake County 87 kmPlumas County 109 kmYolo County 110 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
2:50 pm PDT on 13 May 2017 ()
Where
9 km (6 mi) south of Hamilton City, CA · earthquakes near Hamilton City
Magnitude
M 2.1 (md)
Depth
22 km below the surface
Felt
no reports yet
Nearest
Glenn County, 33 km WSW
Nearest mapped fault
Great Valley thrust fault system, 23 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 3468 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Hamilton City, 9 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: Orland, Chico, Durham, Willows.

How big was it?

This earthquake released about 44 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 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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. 5.7 The 1975 Oroville, California Earthquake · 49 km ESE 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 39.6640, -122.0295. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Glenn County, CA 33 km (20 mi) WSW earthquakes near Glenn County
Butte County, CA 36 km (23 mi) E earthquakes near Butte County
Tehama County, CA 54 km (34 mi) NNW earthquakes near Tehama County
Colusa County, CA 57 km (35 mi) SSW earthquakes near Colusa County
Yuba County, CA 73 km (46 mi) SE earthquakes near Yuba County
Sutter County, CA 75 km (47 mi) SSE earthquakes near Sutter County

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

Aftershocks so far

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

  1. 1.9 14km ENE of Willows, CA
  2. 2.7 6km ENE of Durham, CA
  3. 2.3 9km NE of Orland, CA
  4. 1.6 24km NE of Alder Springs, CA
  5. 2.0 2km E of Hamilton City, CA
  6. 2.0 16km SE of Willows, CA
  7. 1.7 10km N of Thermalito, CA
  8. 2.1 9km NW of Hamilton City, CA
  9. 2.1 3km NW of Oroville East, CA
  10. 1.8 10km N of Oroville, CA
  11. 1.7 18km E of Willows, CA
  12. 1.8 11km N of Oroville, CA
  13. 2.2 10km NE of Orland, CA
  14. 1.8 11km N of Oroville, CA
  15. 1.7 10km N of Thermalito, 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.