Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Arbuckle, CA
No earthquake was likely felt in Arbuckle in the 24 hours to 9:03 am PST (17:03 UTC). The last one was M 4.0, 94 km (58 mi) NW, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Arbuckle
This page: a magnitude 1.8 earthquake was recorded 22 km (14 mi) southwest of Arbuckle, CA, at 4:50 pm PDT on 17 August 2019 (23:50 UTC), 18 km deep.
USGS: 22km SW of Arbuckle, CA
75 km (47 mi) WNW of Sacramento, CA · 48 km (30 mi) WNW of Woodland, CA
- When
- 4:50 pm PDT on 17 August 2019 ()
- Where
- 22 km (14 mi) southwest of Arbuckle, CA · earthquakes near Arbuckle
- Magnitude
- M 1.8 (md)
- Depth
- 18 km below the surface
- Felt
- no reports yet
- Nearest
- Colusa County, 33 km N
- Nearest mapped fault
- Great Valley thrust fault system, 7 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 2631 days ago
Earthquake alerts for Arbuckle, CA
Get a notification in this browser when USGS records an earthquake near Arbuckle, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 Arbuckle, 22 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: Dunnigan, Esparto, Hidden Valley Lake.
How big was it?
This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 900,000× the energy of this one
- Magna, Utah 2020 M 5.7 640,000× the energy of this one
- Around the size people start to feel M 3.0 57× the energy of this one
- This earthquake M 1.8 about 17 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 4.2 on 2018-01-18 — about 3,800 times the energy of this one.
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 38.8792, -122.2375. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Colusa County, CA | 33 km (21 mi) | N | earthquakes near Colusa County |
| Yolo County, CA | 37 km (23 mi) | SE | earthquakes near Yolo County |
| Napa County, CA | 42 km (26 mi) | S | earthquakes near Napa County |
| Sutter County, CA | 49 km (31 mi) | ENE | earthquakes near Sutter County |
| Lake County, CA | 51 km (32 mi) | WNW | earthquakes near Lake County |
| Sonoma County, CA | 72 km (44 mi) | WSW | earthquakes near Sonoma County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
55 earthquakes have been recorded within 50 km since this one.
- 1.9 3km NW of The Geysers, CA
- 1.9 3km NNW of The Geysers, CA
- 1.6 3km SE of The Geysers, CA
- 1.6 2km NW of The Geysers, CA
- 1.9 3km NNW of The Geysers, CA
- 1.6 3km NW of The Geysers, CA
- 2.0 3km SSE of The Geysers, CA
- 1.9 3km WSW of Anderson Springs, CA
- 2.1 1km ESE of The Geysers, CA
- 1.7 14km E of Angwin, CA
- 1.8 14km E of Angwin, CA
- 1.9 2km NW of The Geysers, CA
- 2.0 4km NNW of The Geysers, CA
- 1.7 14km E of Angwin, CA
- 1.6 4km SW of Anderson Springs, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.