Earthquake · automatic estimate, may change
M 1.6md
Earthquake near Saint Helena, CA
No earthquake was likely felt in Saint Helena in the 24 hours to 7:32 am PST (15:32 UTC). The last one was M 1.7, 11 km (7 mi) SSW, at 12:33 am PDT on 25 October 2026, estimated intensity II (weak) in town. Every earthquake near Saint Helena
This page: a magnitude 1.6 earthquake was recorded 3 km (2 mi) north-northwest of Saint Helena, CA, at 1:56 am PST on 16 December 2024 (09:56 UTC), 7.9 km deep. The magnitude and location are an automatic first estimate and may change.
USGS: 3 km of Saint Helena, CA
84 km (52 mi) N of San Francisco, CA · 22 km (14 mi) ENE of Santa Rosa, CA
- When
- 1:56 am PST on 16 December 2024 ()
- Where
- 3 km (2 mi) north-northwest of Saint Helena, CA · earthquakes near Saint Helena
- Magnitude
- M 1.6 (md)
- Depth
- 7.9 km below the surface
- Felt
- no reports yet
- Nearest
- Napa County, 14 km ESE
- Nearest mapped fault
- West Napa fault, 4 km from its surface trace — near is not the same as on
- Status
- Automatic — a machine’s first estimate, which may change
USGS · last changed by USGS · we first saw it 696 days ago
Earthquake alerts for Saint Helena, 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 8 km (5 mi) from the epicentre. In Saint Helena, 3 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: Angwin 5 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
- Around the size people start to feel M 3.0 130× the energy of this one
- This earthquake M 1.6 about 7.6 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 5.0 on 2016-12-14 — about 130,000 times the energy of this one.
Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:
- 6.0 The 2014 South Napa, California Earthquake · 38 km SSE of this epicentre
- 5.3 3 km E of Bloomfield, California · 37 km SW of this epicentre
- 5.3 Northern California · 38 km SW 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 38.5315, -122.4782. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Napa County, CA | 14 km (8 mi) | ESE | earthquakes near Napa County |
| Sonoma County, CA | 39 km (24 mi) | W | earthquakes near Sonoma County |
| Yolo County, CA | 53 km (33 mi) | ENE | earthquakes near Yolo County |
| Solano County, CA | 55 km (34 mi) | ESE | earthquakes near Solano County |
| Marin County, CA | 58 km (36 mi) | SSW | earthquakes near Marin County |
| Lake County, CA | 68 km (42 mi) | NNW | earthquakes near Lake 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.
- 1.6 5 km WNW of Cobb, CA
- 1.7 6 km NNW of The Geysers, CA
- 1.8 5 km NNW of The Geysers, CA
- 2.0 6 km WNW of Cobb, CA
- 1.9 5 km WNW of Cobb, CA
- 4.7 4 km NW of Cobb, CA
- 1.9 4 km NW of Cobb, CA
- 1.6 3 km ESE of The Geysers, CA
- 1.6 12 km E of Cloverdale, CA
- 1.9 12 km NW of The Geysers, CA
- 1.8 8 km NNW of The Geysers, CA
- 2.2 10 km NW of The Geysers, CA
- 1.8 5 km SW of Kenwood, CA
- 2.4 5 km WNW of Cobb, CA
- 1.6 2 km NNE of The Geysers, 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.