Earthquake · reviewed by a seismologist
M 2.4md
Earthquake near Boonville, CA
No earthquake was likely felt in Boonville in the 24 hours to 5:51 pm PST (01:51 UTC). The last one was M 4.0, 65 km (41 mi) NNE, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Boonville
This page: a magnitude 2.4 earthquake was recorded 6 km (4 mi) south of Boonville, CA, at 8:38 pm PDT on 18 September 2016 (03:38 UTC), 1.6 km deep. 8 people have reported feeling it to USGS.
USGS: 6 km S of Boonville, California
81 km (50 mi) NW of Santa Rosa, CA
- When
- 8:38 pm PDT on 18 September 2016 ()
- Where
- 6 km (4 mi) south of Boonville, CA · earthquakes near Boonville
- Magnitude
- M 2.4 (md)
- Depth
- 1.6 km below the surface
- Felt
- 8 reports · strongest reported intensity III
- Nearest
- Mendocino County, 54 km N
- Nearest mapped fault
- San Andreas fault, 20 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
Earthquake alerts for Boonville, CA
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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, people at rest would likely notice it out to about 21 km (13 mi) from the epicentre. In Boonville, 6 km away, the estimate is intensity III (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: Boonville 6 km, intensity III. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 120,000× the energy of this one
- Magna, Utah 2020 M 5.7 86,000× the energy of this one
- Around the size people start to feel M 3.0 7.7× the energy of this one
- This earthquake M 2.4 about 120 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:
- 5.2 6 km ESE of Talmage, California · 30 km NE 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 38.9527, -123.3793. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mendocino County, CA | 54 km (33 mi) | N | earthquakes near Mendocino County |
| Lake County, CA | 57 km (36 mi) | ENE | earthquakes near Lake County |
| Sonoma County, CA | 62 km (38 mi) | SE | earthquakes near Sonoma County |
| Colusa County, CA | 102 km (63 mi) | ENE | earthquakes near Colusa County |
| Napa County, CA | 104 km (65 mi) | ESE | earthquakes near Napa County |
| Glenn County, CA | 111 km (69 mi) | NE | earthquakes near Glenn 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.
- 1.5 9 km S of Kelseyville, California
- 1.9 9 km WNW of Cobb, California
- 1.7 11 km WNW of Cobb, California
- 1.5 10 km WNW of Cobb, California
- 3.0 10 km W of Cobb, California
- 5.0 10 km W of Cobb, California
- 1.6 4 km ENE of Hopland, California
- 2.3 10 km W of Cobb, California
- 1.8 9 km W of Cobb, California
- 1.7 9 km WNW of Cobb, California
- 1.8 10 km NE of Philo, California
- 2.0 10 km W of Cobb, California
- 2.0 3 km ESE of Hopland, California
- 2.4 7 km NNE of Hopland, California
- 2.4 7 km NNE of Hopland, 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
- 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.